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Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 03-2017 trié par par titre, page: 0
» $16times 100$ GHz Echelle Grating-Based Wavelength Multiplexer on Silicon-on-Insulator Platform
Résumé:
This letter reports on an Echelle grating demultiplexer for dense wavelength-division-multiplexing applications with 16 channels and 100 GHz channel spacing. The Echelle grating is designed and fabricated on a silicon-on-insulator platform with a silicon guiding layer of 300 nm. The measured insertion losses of the Echelle grating are lower than 2 dB for all channels and the crosstalk is below 15 dB. Error free transmission was obtained for all channels with negligible penalty.
Auteurs: X. Pommarede;K. Hassan;P. Billondeau;V. Hugues;P. Grosse;B. Charbonnier;G.-H. Duan;
Apparue dans: IEEE Photonics Technology Letters
Date publication: 03.-2017, volume: 29, issue:6, pages: 493 - 495
Editeur: IEEE
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» $H_{2}$ Optimal Coordination of Homogeneous Agents Subject to Limited Information Exchange
Résumé:
Controllers with a diagonal-plus-low-rank structure constitute a scalable class of controllers for multi-agent systems. Previous research has shown that diagonal-plus-low-rank control laws appear as the optimal solution to a class of multi-agent $H_{2}$ coordination problems, which arise in the control of wind farms. In this technical note we show that this result extends to the case where the information exchange between agents is subject to limitations. We also show that the computational effort required to obtain the optimal controller is independent of the number of agents and provide analytical expressions that quantify the usefulness of information exchange.
Auteurs: Daria Madjidian;Leonid Mirkin;Anders Rantzer;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 03.-2017, volume: 62, issue:3, pages: 1424 - 1430
Editeur: IEEE
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» $k$ -Connectivity in Random $K$ -Out Graphs Intersecting Erdős-Rényi Graphs
Résumé:
We investigate k -connectivity in secure wireless sensor networks under the random pairwise key predistribution scheme with unreliable links. When wireless communication links are modeled as independent on-off channels, this amounts to analyzing a random graph model formed by intersecting a random K -out graph and an Erdős-Rényi graph. We present conditions on how to scale the parameters of this intersection model so that the resulting graph is k -connected with probability approaching to one (resp. zero) as the number of nodes gets large. The resulting zero-one law is shown to improve and sharpen the previous result on the 1-connectivity of the same model. We also provide numerical results to support our analysis.
Auteurs: Faruk Yavuz;Jun Zhao;Osman Yağan;Virgil Gligor;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 03.-2017, volume: 63, issue:3, pages: 1677 - 1692
Editeur: IEEE
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» 100-MHz GaN-HEMT Class-G Supply Modulator for High-Power Envelope-Tracking Applications
Résumé:
In this paper, a highly efficient class-G supply modulator targeting high-power wideband envelope tracking applications is presented. The maximum output power using a 50% duty cycle at 100-MHz switching frequency is 62 W for a switching between 30 and 50 V delivered in a 25- $Omega $ load. The modulator including its driver circuit reaches an overall efficiency in the range of 97%–88% for switching frequencies from dc to 100 MHz for passive loads in a wide range. The modulator is designed to operate at various supply voltage levels and is evaluated within the range from 20 to 50 V while powering loads from 25 to 100 $Omega $ . The modulator is characterized in terms of efficiency, switching frequency, and nonlinearities.
Auteurs: Nikolai Wolff;Wolfgang Heinrich;Olof Bengtsson;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 03.-2017, volume: 65, issue:3, pages: 872 - 880
Editeur: IEEE
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» 2-D Analytical Modeling of the Electrical Characteristics of Dual-Material Double-Gate TFETs With a SiO2/HfO2 Stacked Gate-Oxide Structure
Résumé:
A physics-based 2-D analytical model for surface potential, electric field, drain current, subthreshold swing (SS) and threshold voltage of dual-material (DM) double-gate tunnel FETs (DG TFETs) with SiO2/HfO2 stacked gate-oxide structure has been developed in this paper. The parabolic-approximationtechnique, with suitable boundary conditions, has been used to solve Poisson’s equation in the channel region. Channel potential model is used to develop electric field expression. The drain current expression is extracted by analytically integrating the band-to-band tunneling generation rate over the channel thickness. Threshold voltage has been extracted by maximum transconductance method. The proposed model also demonstrates that the proper choice of work function for both the latterly contacting gate electrode (near the source and drain) materials which can give better results in terms of input-output characteristics, SS, and {I}_{ math\rm{\scriptscriptstyle ON}}/{I}_{ math\rm{\scriptscriptstyle OFF}} than the conventional TFET devices. Although the proposed model has been primarily developed for Si-channel-based DM DG TFET devices, however, the model has also been shown to be applicable for other materials like SiGe (indirect bandgap) and InAs channel-based TFET structures. The results of the proposed model have been validated against the TCAD simulation results obtained by using SILVACO ATLAS device simulation software.
Auteurs: Sanjay Kumar;Ekta Goel;Kunal Singh;Balraj Singh;Prince Kumar Singh;Kamalaksha Baral;Satyabrata Jit;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 960 - 968
Editeur: IEEE
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» 2-D Analytical Threshold Voltage Model for Dielectric Pocket Double-Gate Junctionless FETs by Considering Source/Drain Depletion Effect
Résumé:
This paper proposes an analytical threshold voltage model for the dielectric pocket double gate (DP-DG) junctionless FETs (JLFETs). The channel potential function has been obtained by solving 2-D Poisson’s equation using an evanescent mode analysis with suitable boundary conditions. The potential function has then been used for modeling the threshold voltage to investigate the effects of the DP thickness and length on the short-channel effects of the structure. The effects of source and drain depletion regions have been included for improving the accuracy of the model. The model results of DP-DG JLFETs have been compared with the simulation data obtained from the 2-D TCAD ATLAS device simulator.
Auteurs: Balraj Singh;Deepti Gola;Kunal Singh;Ekta Goel;Sanjay Kumar;Satyabrata Jit;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 901 - 908
Editeur: IEEE
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» 2.4-GHz $Q$ -Enhanced Lumped Ring Filter With Two Transmission Zeros Using 0.18- $mu$ m SiGe BiCMOS Process
Résumé:
A 2.4-GHz Q-enhanced lumped ring filter with a narrow bandpass response and two stopband-rejection transmission zeros using 0.18- $mu text{m}$ SiGe BiCMOS technology is demonstrated in this letter. A transformer-based Q-enhanced technique is employed to boost the Q-factor of on-chip inductors for low passband insertion loss. The measured results show zero dB insertion loss, 120-MHz 3-dB bandwidth for the passband centered at 2.45 GHz and with two transmission zeros at 2.35 and 2.65 GHz, respectively. The noise figure is about 14.5 dB, IP1dB is about −15.2 dBm and IIP3 is about −4.5 dBm, respectively. The total current consumption is 9.9 mA at 1.8 V supply voltage.
Auteurs: Yu-Chih Hsiao;Chinchun Meng;Shih-Te Yang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 305 - 307
Editeur: IEEE
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» 2016 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications [Conference Reports]
Résumé:
Presents information on the 2016 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications.
Auteurs: Yong Fan;Yu Jian Cheng;Zi Xuan Huang;
Apparue dans: IEEE Microwave Magazine
Date publication: 03.-2017, volume: 18, issue:2, pages: 100 - 102
Editeur: IEEE
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» 2016 Reviewers for IEEE Transactions on Network and Service Management
Résumé:
The success and quality of this journal critically depends on the dedication and expertise of a large number of reviewers. On behalf of the Editorial Board, I would like to thank them for their excellent work.
Auteurs: Rolf Stadler;
Apparue dans: IEEE Transactions on Network and Service Management
Date publication: 03.-2017, volume: 14, issue:1, pages: 2 - 7
Editeur: IEEE
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» 3D Catheter Shape Determination for Endovascular Navigation Using a Two-Step Particle Filter and Ultrasound Scanning
Résumé:
In endovascular catheter interventions, the determination of the three-dimensional (3D) catheter shape can increase navigation information and help reduce trauma. This study describes a shape determination method for a flexible interventional catheter using ultrasound scanning and a two-step particle filter without X-ray fluoroscopy. First, we propose a multi-feature, multi-template particle filter algorithm for accurate catheter tracking from ultrasound images. Second, we model the mechanical behavior of the catheter and apply a particle filter shape optimization algorithm to refine the results from the first step. Finally, the acquired catheter’s 3D shapes are displayed together with the preoperative 3D images of the cardiac structures to provide intuitive endovascular navigation. We validated our method using ultrasound scanning of the straight and curved catheters in a water tank, and the shape determination errors were 1.44 ± 0.38 mm and 1.95 ± 0.46 mm, respectively. Further, endovascular catheter shape determination was validated in a catheter intervention experiment with a heart phantom. The error of the acquired endovascular catheter shape was 2.23 ± 0.87 mm. These results demonstrate that our two-step method is both accurate and effective. Using ultrasound scanning for shape determination of a flexible catheter will be helpful in endovascular interventions, reducing exposure to radiation and providing rich navigation information.
Auteurs: Fang Chen;Jia Liu;Hongen Liao;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 03.-2017, volume: 36, issue:3, pages: 685 - 695
Editeur: IEEE
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» 5G Converged Cell-Less Communications in Smart Cities
Résumé:
Ubiquitous information service converged by different types of heterogeneous networks is one of fundamental functions for smart cities. Considering the deployment of 5G ultra-dense wireless networks, 5G converged cell-less communication networks are proposed to support mobile terminals in smart cities. To break obstacles of heterogeneous wireless networks, the 5G converged cell-less communication network is vertically converged in different tiers of heterogeneous wireless networks and horizontally converged in celled architectures of base stations/ access points. Moreover, the software defined network controllers are configured to manage the traffic scheduling and resource allocation in 5G converged cell-less communication networks. Simulation results indicate the coverage probability and the energy saving at both base stations and mobile terminals are improved by the cooperative grouping scheme in 5G converged cell-less communication networks.
Auteurs: Tao Han;Xiaohu Ge;Lijun Wang;Kyung Sup Kwak;Yujie Han;Xiong Liu;
Apparue dans: IEEE Communications Magazine
Date publication: 03.-2017, volume: 55, issue:3, pages: 44 - 50
Editeur: IEEE
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» 5G Worldwide Developments [Mobile Radio]
Résumé:
Huawei and NTT DOCOMO announced what they claim is the world's first fifth-generation (5G), large-scale field trial in the 4.5-GHz band using new numerology and frame structure complying with the Third Generation Partnership Project (3GPP) 5G New Radio (NR) current agreements. In the trial, 11.29 Gb/s total user throughput and less than 0.5 ms one-way user plane latency were achieved in the macrocell coverage of a real urban application scenario in Yokohama, Japan. The macrocell was made up of one base station that worked in the 4.5-GHz band with 200-MHz bandwidth, 64 transceivers, and 23 pieces of user equipment (UE) of both static and mobile types. The trial combined multiuser (MU), multiple-input, multiple-output (MIMO) technology for simultaneous multiple access and a precoding algorithm that optimizes signals for maximized performance and also limits interuser interference. It achieved a MU-MIMO transmission of a maximum 79.82 b/s/Hz/cell.
Auteurs: Javier Gozalvez;
Apparue dans: IEEE Vehicular Technology Magazine
Date publication: 03.-2017, volume: 12, issue:1, pages: 4 - 11
Editeur: IEEE
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» 9/12 2-D Modulation Code for Bit-Patterned Media Recording
Résumé:
This paper presents a 9/12 2-D modulation code to overcome 2-D interference effects in bit-patterned media recording (BPMR) systems. Next-generation storage systems that are challenged by the superparamagnetic effect require new technologies to be developed, and for magnetic recording, BPMR technology is regarded to be one of the most promising candidates to extend area density beyond 1 Tb/in2. BPMR systems not only help to reduce transition noise and non-linear bit shift, but they also simplify the tracking operation. Nevertheless, some challenges arise for BPMR systems from a signal processing point of view. One of the primary challenges in the systems is the 2-D interference due to the effects of both the along- and across-track intersymbol interference. Moreover, the effect of media noise and the physical limits of the electromechanical components also negatively impact the system performance. The proposed modulation code converts 9 b sequences of user data into 2-D output codewords in 6-by-2 arrays to avoid fatal interference as much as possible, and a reasonable Hamming distance is also ensured for the codeword set. The proposed code achieves gains of about 2 and 1 dB over a system without encoding and a system with 6/8 modulation coding at the same code rate, respectively. Moreover, the performance of the 9/12 2-D modulation codes according to the different array sizes is also investigated.
Auteurs: Chi Dinh Nguyen;Jaejin Lee;
Apparue dans: IEEE Transactions on Magnetics
Date publication: 03.-2017, volume: 53, issue:3, pages: 1 - 7
Editeur: IEEE
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» In Situ Error Detection Techniques in Ultralow Voltage Pipelines: Analysis and Optimizations
Résumé:
In order to achieve high tolerance against process, voltage, and temperature variations in the ultralow voltage (ULV) circuits, in situ error detection and correction (EDAC) techniques were presented. However, circuits adding the capability of error detection incur large hardware overhead, especially in ULV due to larger delay variability. In this paper, we analyze the hardware overhead of error detection techniques in pipelines based on three different sequential elements: flip-flops, two-phase latches, and pulsed latches. By exploiting the cycle-borrowing ability, we propose a technique called sparse insertion of error detecting registers on the two-phase latch-based and pulsed-latch-based pipelines to reduce the sequential logic area. Furthermore, we propose a delay-padding methodology using a multi- V_{t} cell library in ULV circuits to reduce EDAC hardware overhead. The proposed techniques are applied on a benchmark six-stage pipeline operating at 0.35 V in a 65-nm CMOS. The analysis results show that our proposed techniques can reduce the total area by 26%–33% and the error detecting register count by 2.9– 4.3\times compared with conventional EDAC techniques.
Auteurs: Wei Jin;Seongjong Kim;Weifeng He;Zhigang Mao;Mingoo Seok;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 1032 - 1043
Editeur: IEEE
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» A +12-dBm OIP3 60-GHz RF Downconversion Mixer With an Output-Matching, Noise- and Distortion-Canceling Active Balun for 5G Applications
Résumé:
A CMOS millimeter-wave (mmWave) downconversion mixer with a local-oscillator (LO) buffer is proposed for wireless Gb/s data-transfer enabling systems, such as 5G systems. To obtain high linearity at low supply voltages, the proposed mmWave downconversion mixer adopts an on-chip transformer-based topology. In order to achieve differential to single-ended conversion and IF output matching, while maintaining a high linearity performance, the proposed mmWave downconversion mixer incorporates an active balun with common-source and common-drain configurations employing common-mode noise and third-order intermodulation distortion cancellations. The proposed downconversion mixer with active balun and LO buffer was implemented using a 65-nm CMOS process and it draws 18 mA from a 1 V supply voltage. It demonstrates a gain greater than 5.6 dB, noise figure less than 10.9 dB, and third-order output intercept point more than 12.4 dBm, in the band from 57 to 66 GHz.
Auteurs: Chihoon Choi;Ju Ho Son;Ockgoo Lee;Ilku Nam;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 284 - 286
Editeur: IEEE
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» A 0.1–2-GHz Quadrature Correction Loop for Digital Multiphase Clock Generation Circuits in 130-nm CMOS
Résumé:
A 100-MHz–2-GHz closed-loop analog in-phase/ quadrature correction circuit for digital clocks is presented. The proposed circuit consists of a phase-locked loop- type architecture for quadrature error correction. The circuit corrects the phase error to within a 1.5° up to 1 GHz and to within 3° at 2 GHz. It consumes 5.4 mA from a 1.2 V supply at 2 GHz. The circuit was designed in UMC 0.13- \mu text{m} mixed-mode CMOS with an active area of 102,,\mu {math\rm{ m}} \times 95,,\mu {math\rm{ m}} . The impact of duty cycle distortion has been analyzed. High-frequency quadrature measurement related issues have been discussed. The proposed circuit was used in two different applications for which the functionality has been verified.
Auteurs: Immanuel Raja;Vishal Khatri;Zaira Zahir;Gaurab Banerjee;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 1044 - 1053
Editeur: IEEE
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» A 0.2–1.45-GHz Subsampling Fractional- $N$ Digital MDLL With Zero-Offset Aperture PD-Based Spur Cancellation and In Situ Static Phase Offset Detection
Résumé:
A digital fractional- ${N}$ subsampling multiplying delay-locked loop is proposed in this paper. A zero phase-offset latch-based aperture phase detector is introduced in a reference spur cancellation loop to precisely cancel any static phase offset (SPO) between the injected reference and the digitally controlled oscillator (DCO) phases. An in situ detection scheme is employed to directly measure this phase offset accurately by obviating the requirement of a high-speed off-chip measurement setup. Moreover, a mathematical expression is derived for the calculation of reference spur generated from a given SPO. A uniformly distributed switched capacitor-based DCO frequency tuning achieves highly linear gain. The chip prototype is fabricated in a 1.2-V supply, 65-nm LP CMOS technology and covers an output frequency range of 0.2–1.45 GHz while occupying a core area of 0.054 mm2. Measured phase noise at 1.4175 GHz is −95 dBc/Hz at 100-kHz offset, which is 9 dB lower than in phase-locked loop mode of operation.
Auteurs: Somnath Kundu;Bongjin Kim;Chris H. Kim;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 799 - 811
Editeur: IEEE
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» A 0.3 V 10-bit SAR ADC With First 2-bit Guess in 90-nm CMOS
Résumé:
This paper presents the design and implementation of a 10-bit ultra-low voltage energy-efficient successive approximation register (SAR) analog-to-digital converter (ADC). The proposed first 2-bit guess (F2G) scheme reduces the DAC switching energy by 90% and improves the DNL and INL by \sqrt {3} {/2} in theory compared with the conventional approach. By employing majority-vote comparison at the conversions of LSBs, the noise requirement of comparator can be relaxed by half. With the segmented and bundled routing, the parasitic capacitors of bottom-plates of DAC array are reduced to improve power efficiency and speed. Implemented in 90-nm CMOS technology, the test chip occupied a core area of 0.03 mm2. The prototype consumes 67.3 nW at 150 kS/s from a single 0.3 V supply voltage and achieves an ENOB of 8.85 bits and an SFDR of 70.7 dB at Nyquist input, respectively. The resultant Walden’s FoM and Schreier’s FoM are 0.97 fJ/conv.-step and 175.5 dB, respectively.
Auteurs: Jin-Yi Lin;Chih-Cheng Hsieh;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 03.-2017, volume: 64, issue:3, pages: 562 - 572
Editeur: IEEE
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» A 0.5 V 5.96-GHz PLL With Amplitude-Regulated Current-Reuse VCO
Résumé:
This letter proposes an ultralow-power 5.96-GHz phase-locked loop (PLL) with a current-reuse VCO under low supply voltage of 0.5 V. While the current-reuse VCO can achieve lower power consumption, it has the drawback of amplitude-imbalance of differential outputs due to its asymmetric structure. Proposed amplitude regulation technique utilizes only one capacitor at the center-tap of the inductor, which does not require additional power consumption. The proposed PLL was fabricated in a 65-nm CMOS process. It achieved phase noise of −129 dBc/Hz at 10-MHz offset. Total power consumption was 0.69 mW under 0.5 V supply voltage.
Auteurs: Sho Ikeda;Sang_yeop Lee;Hiroyuki Ito;Noboru Ishihara;Kazuya Masu;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 302 - 304
Editeur: IEEE
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» A 0.95-mW 6-b 700-MS/s Single-Channel Loop-Unrolled SAR ADC in 40-nm CMOS
Résumé:
This brief presents a low-power and high-speed single-channel successive approximation register (SAR) analog-to-digital converter (ADC). It uses a loop-unrolled architecture with multiple comparators. Each comparator is used not only to make a comparison but also to store its output and generate an asynchronous clock to trigger the next comparator. The SAR logic is significantly simplified to increase speed and reduce power. The comparator offset and decision time are optimized with a bidirectional single-side switching technique by controlling the input common-mode voltage $V_mathrm{cm}$. To remove the nonlinearity due to the comparators' offset mismatch, a simple and effective $V_mathrm{cm}$- adaptive offset calibration technique is proposed. The prototype ADC in 40-nm CMOS achieves a 35-dB signal to noise-plus-distortion ratio and a 48-dB spurious-free dynamic range at a 700-MS/s sampling rate. It consumes 0.95 mW, leading to a Walden figure-of-merit (FOM) of 30 fJ/conversion-step and a Schreier FOM of 153.4 dB.
Auteurs: Long Chen;Kareem Ragab;Xiyuan Tang;Jeonggoo Song;Arindam Sanyal;Nan Sun;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 03.-2017, volume: 64, issue:3, pages: 244 - 248
Editeur: IEEE
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» A 103.125-Gb/s Reverse Gearbox IC in 40-nm CMOS for Supporting Legacy 10- and 40-GbE Links
Résumé:
This paper presents the first 103.125-Gb/s multilink gearbox (MLG) IC, which facilitates the transport of independent 10- and 40-GbE signals to $4 times 25.78$ Gb/s physical layers, such as 100GBASE-xR4. The IC consumes only 1.37 W while implementing complicated reverse gearbox functionality. The measured TX jitter from 10- and 25-G lanes is 0.407 and 0.448 psrms, respectively. The measured input sensitivities for a BER of $10^{mathrm {-12}}$ of the 10- and 25-G RXs are 20 and 42 mVppd, respectively. The proposed gearbox IC, fabricated in a 40-nm CMOS process, occupies $3.7 times 3.4$ mm2. The power consumption of RX and TX in a 25-G interface is 50.9 and 52 mW, respectively, and those of a 10-G interface are 29 and 24.4 mW, respectively. MLG functionality is verified using embedded self-test logics.
Auteurs: Taehun Yoon;Joon-Yeong Lee;Jinhee Lee;Kwangseok Han;Jeong-Sup Lee;Sangeun Lee;Taeho Kim;Jinho Han;Hyosup Won;Jinho Park;Hyeon-Min Bae;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 688 - 703
Editeur: IEEE
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» A 2.4–3.6-GHz Wideband Subharmonically Injection-Locked PLL With Adaptive Injection Timing Alignment Technique
Résumé:
This paper proposes a wideband subharmonically injection-locked PLL (SILPLL) with adaptive injection timing alignment technique. The SILPLL includes three main circuit blocks: one-oscillator-period constant-delay (OOPCD) divider, timing-adjusted phase detector (TPD), and pulse generator (PG). The proposed injection timing alignment technique can align the injection timing adaptively in a wide range of the output clock frequency using the two blocks (OOPCD and TPD) and a falling edge locking scheme of pulses. It can avoid the risk that SILPLL may lock to the wrong frequency or even fail to lock. The PG block is used for half-integral injection to relax the tradeoff between the phase noise of SILPLL and the output frequency resolution. The OOPCD circuit occupies a negligible area. After the injection timing alignment is finished, the OOPCD is powered off so that no extra power is consumed. The SILPLL is implemented in the 65-nm 1P9M CMOS process. It consumes 8.6 mW at 1.2 V supply and occupies an active core area of 1 \times 0.6 mm2. The measured output frequency range is 2.4~3.6 GHz with an output frequency resolution of 200 MHz and the phase noise is −127.6 dBc/Hz at an offset of 1 MHz from a carrier frequency of 3.4 GHz. The rms jitter integrated from 1 kHz to 30 MHz is less than 112 fs for all the covered frequency points. Under the supply voltage range from 1.1 to 1.3 V and the temperature range from −20 °C to 70 °C, the rms jitter variation of all the covered frequency points is less than 27 fs, which shows good robustness over environmental variation.
Auteurs: Zhao Zhang;Liyuan Liu;Peng Feng;Nanjian Wu;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 929 - 941
Editeur: IEEE
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» A 2.5 GHz Low Power, High- ${Q}$ , Reliable Design of Active Bandpass Filter
Résumé:
In this paper, a variation-aware and reliable design of a fully integrated radio frequency (RF) bandpass filter realized using a voltage differencing transconductance amplifier is presented. The filter is characterized by its high frequency operation, low power consumption, high quality factor, and it is insensitive to process, voltage, and temperature variations. Sensitivity analysis has been performed to analyze the circuit performance in the presence of parasitics. The inductor-less approach finds its application in integrated building blocks of RF front ends, thus eliminating the requirement of off-chip filters in transceivers. Centered at 2.511 GHz and operating within the 36.21 MHz 3-dB bandwidth, the filter draws 0.168 mA from a ±1 V power supply, attains a voltage gain of 72.6 dB, a quality factor of 69.34 and noise figure of ~29.6 dB. In addition, it has a dynamic range of 125.84 dB-Hz and a 1-dB compression of −1.5 dBm which translates into a figure of merit as high as 94 dB.
Auteurs: Vikash Kumar;Rishab Mehra;Aminul Islam;
Apparue dans: IEEE Transactions on Device and Materials Reliability
Date publication: 03.-2017, volume: 17, issue:1, pages: 229 - 244
Editeur: IEEE
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» A 210-GHz SiGe Balanced Amplifier for Ultrawideband and Low-Voltage Applications
Résumé:
This letter presents a low-voltage balanced amplifier for millimeter-wave radio systems. An ultrawideband of operation is demonstrated from 155 to 210 GHz, which corresponds to a 30% relative bandwidth. Over this band, the system provides 10-dB gain for a power consumption of only 16.8 mW. For the employed 0.8 V voltage supply, the large-signal characterizations demonstrated a maximum iP $_{mathrm {mathbf {1 {}dB}}}$ of −17.1 dBm and oP $_{mathrm {mathbf {1 {}dB}}}$ of −10.2 dBm. The measured input and output return losses are above 10 and 20 dB for the whole band. The described features are enabled by the balanced common-base architecture, the ad hoc designed multistub matching networks, and the employed high performance 450-GHz SiGe BiCMOS fabrication technology. The realized amplifier compares well against reported SiGe BiCMOS designs operating above 200 GHz by showing the widest demonstrated bandwidth as well as the lowest voltage supply and power consumption.
Auteurs: Paolo Valerio Testa;Corrado Carta;Bernhard Klein;Ronny Hahnel;Dirk Plettemeier;Frank Ellinger;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 287 - 289
Editeur: IEEE
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» A 25 Gb/s 1.13 pJ/b −10.8 dBm Input Sensitivity Optical Receiver in 40 nm CMOS
Résumé:
This paper describes the design of a 25 Gb/s energy-efficient CMOS optical receiver with high input sensitivity. By incorporating a current-boosting preamplifier with a dual-path time-interleaved integrating-type optical receiver, it provides 1:2 demultiplexing operation with a tolerance to lower bandwidth photodiodes. The bandwidth of current amplifier is chosen as $0.35times $ operating data rate for maximizing the receiver signal-to-noise ratio. Experimental results show that the receiver can achieve 25 Gb/s operation when integrated with a 9 or 17 GHz GaAs photodiode. Input sensitivities in the two cases are −7.2 dBm (w/i a 9 GHz photodiode) and −10.8 dBm (w/i a 17 GHz photodiode), respectively, for a bit error rate of less than $10^{-12}$ . In addition, a single-tap decision-feedback equalizer (DFE) is embedded to compensate photodiode bandwidth and improve input sensitivity. Integrated with a low-cost 9 GHz photodiode, the input sensitivity and timing margin of the receiver are improved by 2 dB and 0.25 UI, respectively, after DFE compensation. By utilizing a current integrator and time-interleaved comparators, its energy efficiency is 1.13 pJ/b at 25 Gb/s under a 1.2 V power supply. Fabricated in a 40 nm bulk-CMOS technology, the core circuit occupies a chip area of 0.007 mm2 only.
Auteurs: Shih-Hao Huang;Wei-Zen Chen;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 747 - 756
Editeur: IEEE
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» A 28-Gb/s Receiver With Self-contained Adaptive Equalization and Sampling Point Control Using Stochastic Sigma-Tracking Eye-Opening Monitor
Résumé:
This paper describes a 28-Gb/s receiver IC with self-contained adaptive equalization and sampling point control using an on-chip stochastic sigma-tracking eye-opening monitor (SSEOM). The proposed SSEOM accurately detects the bit-error-rate (BER)-related eye contour efficiently without the use of an external microcontroller. The SSEOM determines the BER-optimal sampling point and equalizer coefficients on the basis of pattern-filtered eye diagrams. It also features a background adaptation scheme for robust long-term operation by tracking temperature variations and device aging. The proposed SSEOM is integrated in a 28-Gb/s receiver that is designed to compensate for channel loss up to 25 dB at the Nyquist rate by using a continuous time linear equalizer (CTLE) and a one-tap decision feedback equalizer (DFE) together with an one-tap pre-emphasis at a transmitter. The time required for complete adaptation and the total power consumption are 364 ms and 43.9 mW, respectively. The proposed 28-Gb/s receiver is fabricated in 40 nm CMOS.
Auteurs: Hyosup Won;Joon-Yeong Lee;Taehun Yoon;Kwangseok Han;Sangeun Lee;Jinho Park;Hyeon-Min Bae;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 03.-2017, volume: 64, issue:3, pages: 664 - 674
Editeur: IEEE
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» A 3-D Wideband Model Based on Dynamic Evolution of Scatterers for HAP-MIMO Channel
Résumé:
A theoretical 3-D wideband model based on the dynamic evolution of scatterers for high altitude platform multiple-input multiple-output channel is proposed. In this letter, we consider the dynamic properties of scatterers that scatterers could re-appear after they have vanished, and an $M$ -step, two-state Markov process is used to model the dynamic evolution of scatterers. The Chapman–Kolmogorov equations are used to derive the survival probabilities of scatterers and the complexity is reduced by using eigenvalue decomposition. The space-time-frequency correlation function is derived, and numerical results show that an $M$ -step Markov process is indispensable to investigate the dynamic properties of scatterers.
Auteurs: Zhuxian Lian;Lingge Jiang;Chen He;
Apparue dans: IEEE Communications Letters
Date publication: 03.-2017, volume: 21, issue:3, pages: 684 - 687
Editeur: IEEE
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» A 32-Stage 15-b Digital Time-Delay Integration Linear CMOS Image Sensor With Data Prediction Switching Technique
Résumé:
This paper presents a 512-column linear CMOS image sensor (CIS) with 32-stage digital time-delay integration (TDI) operation. A signal processing architecture consists of analog-front-ends, analog-to-digital converters (ADCs), and digital accumulators (DAs) are designed with optimization of timing, area, and power efficiency. An eight-column-shared 10-b successive approximation register ADC with data prediction switching technique and 11-b DA are proposed to achieve a data depth of 15 b after 32-stage TDI. The achieved signal-to-noise ratio boost is 14.84 dB after 32-stage TDI operation. The proposed linear TDI sensor is implemented in 0.11- \mu text{m} TSMC backside illumination CIS technology with a line time of 104~\mu text{s} , a pixel pitch of 7.5~\mu text{m} , and a power consumption of 153.2~\mu text{W} /column.
Auteurs: Chin Yin;Ting Liao;Kuan-Lin Liu;Chen-Che Kao;Chin-Fong Chiu;Chih-Cheng Hsieh;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 1167 - 1173
Editeur: IEEE
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» A 36-V 49% Efficient Hybrid Charge Pump in Nanometer-Scale Bulk CMOS Technology
Résumé:
This paper introduces a hybrid charge pump (HCP) architecture. The HCP enables high-voltage dc outputs in a nanometer-scale CMOS technology at improved power efficiency by optimally mixing different charge pump (CP) types that trade off voltage range and power efficiency. Conventional CP outputs in a bulk CMOS process are limited to a single-diode breakdown voltage ( $sim 12$ V in a 65-nm technology node). To support >12 V outputs, the HCP extends the voltage tolerance of bulk CMOS substrates via two technology methods: double-diode substrate isolation and field oxide isolation. To enable these isolation methods, two specialized CP cells are devised: an all-nMOS voltage doubler and an improved-drive Dickson-type pump. Two HCP design examples with opposite voltage polarities are implemented in a 65-nm CMOS technology, and their measurement results are discussed. The positive voltage HCP achieves a 36 V output and 49% peak efficiency at a 20- $mu text{A}$ load current and occupies 0.18 mm $^{mathrm {mathbf {2}}}$ in area. This output voltage represents a $3times $ increase in the technology’s voltage range compared to ranges attainable by conventional designs.
Auteurs: Yousr Ismail;Haechang Lee;Sudhakar Pamarti;Chih-Kong Ken Yang;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 781 - 798
Editeur: IEEE
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» A 370-pJ/b Multichannel BFSK/QPSK Transmitter Using Injection-Locked Fractional-N Synthesizer for Wireless Biotelemetry Devices
Résumé:
This paper presents a 401–428-MHz BFSK/QPSK transmitter (TX) with two types of fractional-injection-locking techniques for multichannel transmission capabilities. A $Delta Sigma$ -based injection-locked ring oscillator is proposed to achieve fine frequency tuning with a frequency resolution of 1.3 kHz. The proposed method facilitates multichannel BFSK modulation. For high data rate wideband QPSK modulation, frequency tuning is achieved through sequential injection locking. The TX performs 550 Kb/s for BFSK and 11 Mb/s for band-shaped QPSK with EVM of 4.4% and 4.9%, respectively. It also achieves a settling time of less than $0.8~mu text{s}$ . This helps to save operating power of the wireless medical devices with duty-cycling protocol employed in the TX. Fabricated in 130-nm process technology, the TX achieves an energy efficiency of 370 pJ/b while delivering −13 dBm of output power with 1-V supply.
Auteurs: Kok-Hin Teng;Chun-Huat Heng;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 867 - 880
Editeur: IEEE
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» A 3D Assembled Silicon-Embedded Transformer for 10-MHz, Ultra-High-Isolation, Compact Chip-to-Chip Power Transfer
Résumé:
In this letter, a 3D assembled silicon-embedded transformer (3DASET) is proposed and demonstrated for low-frequency, ultra-high-isolation, compact power transfer applications. The primary and secondary coils of the 3DASET are embedded inside the primary side and secondary side chips, respectively, from the backside to achieve a large coil thickness and a whole-area utilization for each coil, as well as simple fabrication and compact integration. The two chips are then back-to-back bonded, and ultra-high isolation can be achieved with a sufficiently strong and thick isolation layer between the chips. The 2-mm2 3DASET fabricated can work at a low frequency of 10 MHz with a reasonable efficiency of 70%, which is essential for reducing the switching and rectifying losses of the system. A high isolation capability of over 4.5 kV can also be achieved.
Auteurs: Rongxiang Wu;Niteng Liao;Xiangming Fang;Jian Cai;Qian Wang;Johnny K. O. Sin;
Apparue dans: IEEE Electron Device Letters
Date publication: 03.-2017, volume: 38, issue:3, pages: 356 - 358
Editeur: IEEE
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» A 3D Localization Approach for Subsea Pipelines Using a Spherical Detector
Résumé:
A 3D localization approach for subsea pipelines is proposed using an internal mobile spherical detector without any external auxiliary location measurements. The process of solving for the pipeline orientation using the magnetic field and acceleration measured simultaneously by the spherical detector is formulated in the rotating sensor frame. Specifically, when the frames of the accelerometer and magnetometer are identical, the measured acceleration can be used to construct the rotation matrix to map the rotating sensor frame to the stationary pipe frame. This transformation by the rotation matrix can be applied to the measured rotating magnetic field to solve the orientation equations. The rolling frequency of the detector is used to calculate the spherical detector’s velocity and mileage within the pipeline. The approach and the system have been successfully applied in a 30-km long oil pipeline. After calibration by aligning the calculated and actual pipeline ends through 3D rotation, an absolute localization error of 1.2 km is achieved. This result is promising as an initial model for future use with external measurements.
Auteurs: Xinjing Huang;Shili Chen;Shixu Guo;Tianshu Xu;Qianli Ma;Shijiu Jin;Gregory S. Chirikjian;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1828 - 1836
Editeur: IEEE
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» A 4-Element 60-GHz CMOS Phased-Array Receiver With Beamforming Calibration
Résumé:
A 4-element 60-GHz phased-array receiver RF front-end (RFE) employing LO-path phase-shifting configuration is presented. A wide bandwidth from 57 to 66 GHz is achieved by using multiple design techniques, including wide-band input matching network using on-chip baluns, peak-frequency staggering in the LNAs, and resonant-frequency tuning of the LC load in the first down-conversion stages. Furthermore, beamforming calibration is implemented by sequentially performing gain equalization, I/Q calibration and successive-approximation phase tuning. Implemented in a 65-nm CMOS process, each element measures gain of 21 dB and NF of 7.2 dB and IP1dB of −21 dBm in high-gain mode while achieves IP1dB of −12.5 dBm with gain of −2 dB and NF of 20 dB in low-gain mode. With beamforming calibration, the peak-to-null ratio of the synthesized 4-element array pattern is improved from 16.5 dB to 28.5 dB, corresponding to phase error of ±0.6° and amplitude mismatch of ±1.1 dB. The whole system consumes 320 mW from a 1.2-V supply and occupies a core area of 2.0\times 1.3 mm2 excluding pads.
Auteurs: Liang Wu;Hiu Fai Leung;Alvin Li;Howard C. Luong;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 03.-2017, volume: 64, issue:3, pages: 642 - 652
Editeur: IEEE
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» A 5.6 ppm/°C Temperature Coefficient, 87-dB PSRR, Sub-1-V Voltage Reference in 65-nm CMOS Exploiting the Zero-Temperature-Coefficient Point
Résumé:
This paper describes an MOSFET-only voltage reference realized in 65-nm CMOS featuring a temperature coefficient (TC) of 5.6 ppm/°C from -40 °C to 125 °C, a power supply rejection ratio of 87 dB from dc up to 800 kHz (and 75 dB at 1 MHz), a minimum supply voltage of 0.8 V, and a power dissipation of 13 $mu text{W}$ . These attributes are achieved by exploiting the zero-TC point of an MOSFET and combining it with a novel curvature-compensation technique, an active attenuator, and an impedance-adapting frequency compensation scheme.
Auteurs: Jize Jiang;Wei Shu;Joseph S. Chang;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 623 - 633
Editeur: IEEE
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» A 58.6 mW 30 Frames/s Real-Time Programmable Multiobject Detection Accelerator With Deformable Parts Models on Full HD $1920times 1080$ Videos
Résumé:
This paper presents a programmable, energy-efficient, and real-time object detection hardware accelerator for low power and high throughput applications using deformable parts models, with $2times $ higher detection accuracy than traditional rigid body models. Three methods are used to address the high computational complexity of eight deformable parts detection: classification pruning for $33times $ fewer part classification, vector quantization for $15times $ memory size reduction, and feature basis projection for $2times $ reduction in the cost of each classification. The chip was fabricated in a 65 nm CMOS technology, and can process full high definition $1920times 1080$ videos at 60 frames/s without any OFF-chip storage. The chip has two programmable classification engines (CEs) for multiobject detection. At 30 frames/s, the chip consumes only 58.6 mW (0.94 nJ/pixel, 1168 GOPS/W). At a higher throughput of 60 frames/s, the CEs can be time multiplexed to detect even more than two object classes. This proposed accelerator enables object detection to be as energy-efficient as video compression, which is found in most cameras today.
Auteurs: Amr Suleiman;Zhengdong Zhang;Vivienne Sze;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 844 - 855
Editeur: IEEE
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» A 60-GHz 4-Gb/s Fully Integrated NRZ-to-QPSK Fiber-Wireless Modulator
Résumé:
A fully integrated optical-to-wireless modulator for low-cost fiber-optical backhaul links is presented in this paper. In the receiver, a CMOS photodetector with a bandwidth of 0.5 GHz is integrated to perform optical-to-electrical conversion. A gain-boosted inverter based transimpedance amplifier achieves a high gain-bandwidth product without using inductive peaking. The two-stage equalizer compensates the photodetector bandwidth and extends the operation data rate to 4 Gb/s. The wireless modulator directly up-converts and modulates the baseband I/Q NRZ data to a QPSK signal centered at 60 GHz. Realized in 65-nm CMOS, the optical front-end achieves -3-dBm optical input sensitivity at 4 Gb/s with 10^{math\rm {-12}} BER. The modulator produces -7.2-dBm output power with -12-dB EVM at a bit efficiency of 19.6 pJ/b. This design demonstrates that a small form factor and low cost optical-to-millimeter-wave modulator can be realized to support future fiber-wireless networks.
Auteurs: Yipeng Wang;Duona Luo;Quan Pan;Liwen Jing;Zhixin Li;C. Patrick Yue;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 03.-2017, volume: 64, issue:3, pages: 653 - 663
Editeur: IEEE
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» A 60-GHz CMOS Frequency Tripler With Broadband Performance
Résumé:
A 60-GHz differential frequency tripler with broadband performance was implemented in 90-nm CMOS technology. A $text{G}_{mathrm {mathbf {m}}}$ -boosted topology and notch filter were used in a fully differential cascode configuration to improve the performance of broadband and harmonic suppression. The proposed frequency tripler exhibits a measured 3-dB bandwidth ranging from 51.3 to 70.2 GHz, with a minimum conversion loss of 5.24 dB at 60 GHz. Compared with the third-harmonic frequency, the fundamental frequency and second-harmonic frequency are suppressed by more than 29.2 and 33.7 dBc, respectively.
Auteurs: Min-Li Chou;Hsien-Chin Chiu;Hsuan-Ling Kao;Fan-Hsiu Huang;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 281 - 283
Editeur: IEEE
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» A 650-GHz Backward Wave Oscillator Based on Axial Loaded Double Defected-Photonic Crystal SWS
Résumé:
Axial loaded Double Defected Photonic Crystal (ADD-PC) with a cylindrical beam channel is introduced as a slow-wave structure (SWS) for backward wave oscillator (BWO) source design. The structural and the geometrical dimensions of the proposed SWS for submillimeter wave regime are realizable using the modern microfabrication processes. Starting from the basic design; the dispersion diagram, the modal phase velocity, and the beam interaction impedance are calculated. The effect of fabrication tolerance on both the operating frequency and the beam interaction impedance is also discussed. Using a custom built numerical electron beam–wave interaction algorithm, the electromagnetic field generation supported by the ADD-PC SWS is analyzed thoroughly. Simulation results indicate that with the proposed BWO, an output power of almost 8 W at 650 GHz with 1.8% conversion efficiency can be achieved.
Auteurs: Ahmed I Nashed;Sujeet K. Chaudhuri;Safieddin Safavi-Naeini;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 03.-2017, volume: 45, issue:3, pages: 372 - 380
Editeur: IEEE
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» A 70-GHz LO Phase-Shifting Bidirectional Frontend Using Linear Coupled Oscillators
Résumé:
A 70-GHz two-element bidirectional frontend is demonstrated with linear coupled oscillators in a 90-nm silicon–germanium BiCMOS process. The transmitter has a measured peak output power of 7.2 dBm and a peak conversion gain of 14.5 dB while consuming 47 mA from a 1.8-V supply. The receiver has a peak conversion gain of 9.9 dB and a minimum noise figure of 8.6 dB with a nominal current consumption of 18 mA from a 1.5-V supply. The frontend is integrated with a two-element linear coupled oscillator array and achieves a maximum phase scanning of ±80°.
Auteurs: Tissana Kijsanayotin;Jun Li;James F. Buckwalter;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 03.-2017, volume: 65, issue:3, pages: 892 - 904
Editeur: IEEE
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» A 75-MHz Continuous-Time Sigma–Delta Modulator Employing a Broadband Low-Power Highly Efficient Common-Gate Summing Stage
Résumé:
A wide-bandwidth (BW) power-efficient continuous-time $Sigma Delta $ modulator (CT $Sigma Delta text{M}$ ) is presented. The modulator introduces a third-order filter implemented with a lossless integrator and a multiple-feedback single-amplifier biquadratic filter with embedded loop stability compensation. An active summing block is implemented by employing a common-gate current buffer followed by a transimpedance amplifier. This combination relaxes the specification requirements of the operational amplifier by making its required BW independent of the closed-loop gain. The proposed technique achieves optimum BW with reduced power consumption, making it functional for over gigahertz operation. Fabricated in a standard 40-nm CMOS technology, and clocked at 3.2 GHz, the CT $Sigma Delta text{M}$ achieves a signal-to-noise-and-distortion ratio of 65.5 dB over 75-MHz BWwhile consuming 22.8 mW of power. The obtained Walden’s figure of merits is 98 fJ/conv-step.
Auteurs: Carlos Briseno-Vidrios;Alexander Edward;Ayman Shafik;Samuel Palermo;Jose Silva-Martinez;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 657 - 668
Editeur: IEEE
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» A 92-dB DR, 24.3-mW, 1.25-MHz BW Sigma–Delta Modulator Using Dynamically Biased Op Amp Sharing
Résumé:
A 2–2 cascaded switched-capacitor \Sigma \Delta modulator is presented for design of low-voltage, low-power, broadband analog-to-digital conversion. To reduce power dissipation in both analog and digital circuits and ensure low-voltage operation, a half-sample delayed-input feedforward architecture is employed in combination with 4-bit quantization, which results in reduced integrator output swings and relaxed timing constraint in the feedback path. The integrator power is further reduced by sharing an op amp in the two integrators in each stage and periodically changing the op amp bias condition between a high-current and a low-current mode using a fast low-power high-precision charge pump circuit. Implemented in a 0.18- \mu text{m} CMOS technology, the experimental prototype achieves a 92-dB dynamic range, a 91-dB peak signal-to-noise ratio, and an 84-dB peak signal-to-noise plus distortion ratio, respectively for a signal bandwidth of 1.25 MHz. Operated at a 40-MHz sampling rate, the modulator dissipates 24.3 mW from a 1 V supply.
Auteurs: Je-Kwang Cho;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 881 - 893
Editeur: IEEE
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» A Bit-Plane Decomposition Matrix-Based VLSI Integer Transform Architecture for HEVC
Résumé:
In this brief, a new very-large-scale integrated (VLSI) integer transform architecture is proposed for the High Efficiency Video Coding (HEVC) encoder. The architecture is designed based on the signed bit-plane transform (SBT) matrices, which are derived from the bit-plane decompositions of the integer transform matrices in HEVC. Mathematically, an integer transform matrix can be equally expressed by the binary weighted sum of several SBT matrices that are only composed of binary 0 or ±1. The SBT matrices are very simple and have lower bit width than the original integer transform in the form. The SBT matrices are also sparse and there are many zero elements. The sparse characteristic of SBT matrices is very helpful for saving the addition operators of SBT. In the proposed architecture, instead of the original integer transform in high bit width, the video data can be respectively transformed with the SBT matrices in lower bit width. As a result, the delay of the transform unit circuit can be significantly reduced with the proposed SBT. Moreover, exploiting the redundant element characteristic of SBT matrices, in which the elements are 0 or ±1, the adder reuse strategy is proposed for our transform architecture, which can save the circuit area efficiently. The simulation results show that by employing the proposed strategies the VLSI transform architecture can be synthesized in a proper area with a high working frequency and low latency. The architecture can support all HEVC encoders coding ultra high-definition video sequences in real time.
Auteurs: Honggang Qi;Qingming Huang;Wen Gao;
Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs
Date publication: 03.-2017, volume: 64, issue:3, pages: 349 - 353
Editeur: IEEE
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» A BNBF User Selection Scheme for NOMA-Based Cooperative Relaying Systems With SWIPT
Résumé:
In this letter, we investigate the outage performance of cooperative relaying transmissions in two-user non-orthogonal multiple access systems, wherein simultaneous wireless information and power transfer is employed at the near users to power their relaying operations. To this end, a best-near best-far (BNBF) user selection scheme is proposed. Considering three relaying protocols, i.e., decode-and-forward (DF), amplify-and-forward (AF), and hybrid DF/AF protocols, tight closed-form approximate expressions for the outage probability are derived to evaluate the system performance. Numerical results reveal that, for any relaying protocols used, the diversity order achieved by the BNBF scheme is $M+1$ , where $M$ is the number of far users, and does not depend on the number of near users.
Auteurs: Nhu Tri Do;Daniel Benevides Da Costa;Trung Q. Duong;Beongku An;
Apparue dans: IEEE Communications Letters
Date publication: 03.-2017, volume: 21, issue:3, pages: 664 - 667
Editeur: IEEE
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» A Broadband and High-Gain Planar Complementary Yagi Array Antenna With Circular Polarization
Résumé:
A novel planar end-fire circularly polarized (CP) complementary Yagi array antenna is proposed. The antenna has a compact and complementary structure, and exhibits excellent properties (low profile, single feed, broadband, high gain, and CP radiation). It is based on a compact combination of a pair of complementary Yagi arrays with a common driven element. In the complementary structure, the vertical polarization is contributed by a microstrip patch Yagi array, while the horizontal polarization is yielded by a strip dipole Yagi array. With the combination of the two orthogonally polarized Yagi arrays, a CP antenna with high gain and wide bandwidth is obtained. With a profile of $0.05lambda _{mathrm{0}}$ (3 mm), the antenna has a gain of about 8 dBic, an impedance bandwidth ( $vert S_{11}vert < -10 $ dB) of 13.09% (4.57–5.21 GHz) and a 3-dB axial-ratio bandwidth of 10.51% (4.69–5.21 GHz).
Auteurs: Wenlong Zhou;Juhua Liu;Yunliang Long;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1446 - 1451
Editeur: IEEE
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» A Carrier-Based PWM Scheme for Neutral Point Voltage Balancing in Three-Level Inverter Extending to Full Power Factor Range
Résumé:
This paper proposes a unique carrier-based pulse width modulation strategy for a three-level neutral-point-clamped inverter that works satisfactorily and with uniform convergence time over the full power factor (PF) range of the load variation. It has excellent control over capacitor voltages and mitigates low-frequency oscillations in the neutral point for the full PF range. First, an investigation is made to see how the load currents get modulated to generate compensating neutral current causing charging and discharging of dc-link capacitors. It is observed that when an additional modulating voltage signal that is in phase with the corresponding phase current is added in each phase, a neutral current is produced in the right direction which can be used to compensate for any prior unbalance in capacitor voltages. It is demonstrated that the performance of this scheme is insensitive to the load PF variation (full range from zero to unity). It performs satisfactorily throughout the entire linear modulation range and eliminates any undesirable low-frequency harmonic component in the compensating neutral current. The effectiveness of the proposed scheme is verified through simulation and experimental results by varying load PF as well as modulation index with both passive and motor loads.
Auteurs: Santu Kr. Giri;Sibaprasad Chakrabarti;Subrata Banerjee;Chandan Chakraborty;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 1873 - 1883
Editeur: IEEE
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» A CCA and ICA-Based Mixture Model for Identifying Major Depression Disorder
Résumé:
The fMRI signals are usually filtered before processing and analyzing. This process can result in the loss of information carried by the higher frequency in the low frequency fluctuation. ICA and CCA are two classical methods in fMRI. ICA finds the statistically independent components of the observed data, however these components are usually physiologically uninterpretable without auxiliary procedures. CCA decomposes two sets of data into component pairs in some order, however these components may be mixtures of real signals and noise. In order to obtain statistically independent components and avoid the loss of information in the process of filtering, we propose a mixed model based on ICA and CCA, which does not need to filter the data. It is shown by the experiments that the new model has some advantages compared with the classical ICA and CCA. The components obtained by the new model is statistically independent. The useful information included in the low frequency fluctuation can be preserved. Experiments on synthetic data show satisfying results. As an application, this new model is used to design an algorithm to discriminate the major depressions from normal controls, with encouraging experimental results.
Auteurs: Wuhong Lin;Huawang Wu;Yishu Liu;Dongsheng Lv;Lihua Yang;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 03.-2017, volume: 36, issue:3, pages: 745 - 756
Editeur: IEEE
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» A Chalcogenide Multimode Interferometric Temperature Sensor Operating at a Wavelength of $2~mutext{m}$
Résumé:
This paper investigated the fabrication of a singlemode-multimode-singlemode fiber structure based on a chalcogenide (As2S3 and AsxS1-x) multimode fiber sandwiched between two standard silica singlemode fibers using a commercial fiber fusion splicer. The temperature dependence of this hybrid fiber structure was investigated and a first proof of concept showed that the hybrid SMS fiber structure has an average experimental temperature sensitivity of circa 84.38 pm/°C over a temperature range of 20 °C~100°C at the wavelength range around 2~\mu text{m} . The measured results show a general agreement with numerical simulations based on a guided-mode propagation analysis method. Our result provides a potential platform for the development of compact, high-optical-quality, and robust sensing devices operating at the midinfrared wavelength range.
Auteurs: Lin She;Pengfei Wang;Weimin Sun;Xianfan Wang;Wenlei Yang;Gilberto Brambilla;Gerald Farrell;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1721 - 1726
Editeur: IEEE
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» A Cloud Computing Solution for the Efficient Implementation of the P-SBAS DInSAR Approach
Résumé:
We present an efficient Cloud Computing (CC) implementation of the Parallel Small BAseline Subset (P-SBAS) algorithm, which is an advanced Differential Interferometric Synthetic Aperture Radar (DInSAR) technique for the generation of Earth surface displacement time series through distributed computing infrastructures. The rationale of our approach consists in properly distributing the large data volumes and the processing tasks involved in the P-SBAS chain among the available (virtual and/or physical) computing nodes of the CC infrastructure, so that each one of these elements can concurrently work on data that are physically stored on its own local volume. To do this, both an ad hoc management of the data flow and an appropriate scheduling of the parallel jobs have been also implemented to properly handle the high complexity of the P-SBAS workflow. The proposed solution allows minimizing the overall data transfer and network load, thus improving the P-SBAS efficiency and scalability within the exploited CC environments. The presented P-SBAS implementation has been extensively validated through two experimental analyses, which have been carried out by exploiting the Amazon Web Services (AWS) Elastic Cloud Compute (EC2) resources. The former analysis involves the processing of a large (128 SAR images) COSMO-SkyMed dataset, which has been performed by exploiting up to 64 computing nodes, and is aimed at demonstrating the P-SBAS scalable performances. The latter allows us to show the P-SBAS capability to generate DInSAR results at a regional scale (150 000 km2 in Southern California) in a very short time (about 9 h), by simultaneously processing 18 ENVISAT frames that correspond to a total of 741 SAR images, exploiting in parallel 144 AWS computing nodes. The presented results confirm the effectiveness of the proposed P-SBAS CC solution, which may contribute to further extend the frontiers of the DInSAR investigation at a very large scale.
Auteurs: Ivana Zinno;Francesco Casu;Claudio De Luca;Stefano Elefante;Riccardo Lanari;Michele Manunta;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 03.-2017, volume: 10, issue:3, pages: 802 - 817
Editeur: IEEE
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» A Cloud Reservation System for Big Data Applications
Résumé:
Emerging Big Data applications increasingly require resources beyond those available from a single server and may be expressed as a complex workflow of many components and dependency relationships—each component potentially requiring its own specific, and perhaps specialized, resources for its execution. Efficiently supporting this type of Big Data application is a challenging resource management problem for existing cloud environments. In response, we propose a two-stage protocol for solving this resource management problem. We exploit spatial locality in the first stage by dynamically forming rack-level coalitions of servers to execute a workflow component. These coalitions only exist for the duration of the execution of their assigned component and are subsequently disbanded, allowing their resources to take part in future coalitions. The second stage creates a package of these coalitions, designed to support all the components in the complete workflow. To minimize the communication and housekeeping overhead needed to form this package of coalitions, the technique of combinatorial auctions is adapted from market-based resource allocation. This technique has a considerably lower overhead for resource aggregation than the traditional hierarchically organized models. We analyze two strategies for coalition formation: the first, history-based uses information from past auctions to pre-form coalitions in anticipation of predicted demand; the second one is a just-in-time that builds coalitions only when support for specific workflow components is requested.
Auteurs: Dan C. Marinescu;Ashkan Paya;John P. Morrison;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 03.-2017, volume: 28, issue:3, pages: 606 - 618
Editeur: IEEE
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» A CMOS Monolithic Position-Sensitive Detector With Stray Illumination Noise Removal for Light-Spot Position Detection Applications
Résumé:
In this paper, a novel CMOS monolithic position-sensitive detector (PSD) with stray illumination noise removal for light spot position detection applications is proposed. The light sensor and analog processing circuits are monolithically and compactly integrated. Compared with devices developed in previous studies, the proposed monolithic PSD not only has the basic functions of PSDs, but also achieves stray illumination noise removal. All the functions and performance of the proposed monolithic PSD were successfully tested and demonstrated through measurements. The proposed chip is suitable for devices involving light-spot position detection.
Auteurs: Cheng-Ta Chiang;Yu-Ting Hou;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1918 - 1924
Editeur: IEEE
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» A Coaxial Magnetic Gear With Consequent-Pole Rotors
Résumé:
In this paper, a novel coaxial magnetic gear (MG) is proposed, in which both permanent magnet and consequent poles are employed on the inner and outer rotors. The MG is expected with improved torque transmission capability by increasing the effective magnetic flux and offering additional reluctance torque. Air-gap field distribution and torque–angle characteristic of this MG are analyzed and compared with the conventional MG, which adopts dual surface-mounted permanent magnet rotors. To maximize the torque density, several key design parameters are investigated using finite-element method. Analysis results indicate that the proposed MG with ferrite magnets can largely improve the pull-out torque. In addition, end effect and power losses with different rotor structures are analyzed. Performance of two optimized MGs is then validated with test. Also, the MG cost effectiveness with different magnet materials is presented.
Auteurs: Jian-Xin Shen;Hua-Yang Li;He Hao;Meng-Jia Jin;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 267 - 275
Editeur: IEEE
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» A Cognitive Control Method for Cost-Efficient CBTC Systems With Smart Grids
Résumé:
Communication-based train control (CBTC) systems use wireless local area networks for information transmission between trains and wayside equipment. Since inevitable packet delay and drop are introduced in train–wayside communications, information uncertainties in trains' states will lead to unplanned traction/braking demands, as well as waste in electrical energy. Moreover, with the introduction of regenerative braking technology, power grids in CBTC systems are evolving to smart grids, and cost-aware power management should be employed to reduce the total financial cost of consumed electrical energy. In this paper, a cognitive control method for CBTC systems with smart grids is presented to enhance both train operation performance and cost efficiency. We formulate a cognitive control system model for CBTC systems. The information gap in cognitive control is calculated to analyze how the train–wayside communications affect the operation of trains. The Q-learning algorithm is used in the proposed cognitive control method, and a joint objective function composed of the information gap and the total financial cost is applied to generate optimal policy. The medium-access control layer retry-limit adaption and traction strategy selection are adopted as cognitive actions. Extensive simulation results show that the cost efficiency and train operation performance of CBTC systems are substantially improved using our proposed cognitive control method.
Auteurs: Wenzhe Sun;Fei Richard Yu;Tao Tang;Siqing You;
Apparue dans: IEEE Transactions on Intelligent Transportation Systems
Date publication: 03.-2017, volume: 18, issue:3, pages: 568 - 582
Editeur: IEEE
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» A Collision-Mitigation Cuckoo Hashing Scheme for Large-Scale Storage Systems
Résumé:
With the rapid growth of the amount of information, cloud computing servers need to process and analyze large amounts of high-dimensional and unstructured data timely and accurately. This usually requires many query operations. Due to simplicity and ease of use, cuckoo hashing schemes have been widely used in real-world cloud-related applications. However, due to the potential hash collisions, the cuckoo hashing suffers from endless loops and high insertion latency, even high risks of re-construction of entire hash table. In order to address these problems, we propose a cost-efficient cuckoo hashing scheme, called MinCounter. The idea behind MinCounter is to alleviate the occurrence of endless loops in the data insertion by selecting unbusy kicking-out routes. MinCounter selects the “cold” (infrequently accessed), rather than random, buckets to handle hash collisions. We further improve the concurrency of the MinCounter scheme to pursue higher performance and adapt to concurrent applications. MinCounter has the salient features of offering efficient insertion and query services and delivering high performance of cloud servers, as well as enhancing the experiences for cloud users. We have implemented MinCounter in a large-scale cloud testbed and examined the performance by using three real-world traces. Extensive experimental results demonstrate the efficacy and efficiency of MinCounter.
Auteurs: Yuanyuan Sun;Yu Hua;Dan Feng;Ling Yang;Pengfei Zuo;Shunde Cao;Yuncheng Guo;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 03.-2017, volume: 28, issue:3, pages: 619 - 632
Editeur: IEEE
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» A Community-Driven Access Control Approach in Distributed IoT Environments
Résumé:
The distributed Internet of Things is emerging in the literature as a new paradigm for IoT where remotely controlled smart objects can act on their own to sense/actuate, store, and interpret information either created by them or within the surrounding environment. This paradigm calls for novel security and access control mechanisms to enable smart objects with various resource limitations to evaluate a claimed access right from external entities without relying on central authorization systems. This article proposes utilizing a community-based structure to define the notion of access rights in a distributed IoT environment. With this structure, within a given community of smart objects sharing a common mission, access rights are to be evaluated based on the community norms by smart objects with sufficient resources on behalf of those with resource limitations. A novel, community-driven, access control framework is proposed in addition to a prototype to demonstrate access control granting in a user-friendly manner.
Auteurs: Dina Hussein;Emmanuel Bertin;Vincent Frey;
Apparue dans: IEEE Communications Magazine
Date publication: 03.-2017, volume: 55, issue:3, pages: 146 - 153
Editeur: IEEE
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» A Compact Four-Way Power Combiner
Résumé:
A compact 8-port waveguide network is proposed in this letter. It is constructed by cascading two compact coaxial magic-Ts and one coplanar coaxial waveguide magic-T in series. Based on the 8-port waveguide network, a four-way power combiner is realized with three matching ports connected to loads. Measurements show that from 7.8 to 10.3 GHz, the return loss is greater than 18 dB, the isolation is greater than 21 dB, the insertion loss is less than 0.4 dB, and the amplitude and phase imbalance are less than 0.3 dB and 3°, respectively. Its cross section areas are approximately $1.1lambda times 1.1lambda $ for the central frequency of 9 GHz. The measurements agree well with the simulations.
Auteurs: Letian Guo;Jiawei Li;Wenhua Huang;Hao Shao;Tao Ba;
Apparue dans: IEEE Microwave and Wireless Components Letters
Date publication: 03.-2017, volume: 27, issue:3, pages: 239 - 241
Editeur: IEEE
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» A Compact Ground-Based Interferometric Radar for Landslide Monitoring: The Xerém Experiment
Résumé:
A real-time monitoring system based on ground-based synthetic aperture radar interferometry (GB-InSAR) were developed and deployed with the objective to gain understanding of landslide dynamics in an area in Xerém (district of Duque de Caxias - RJ, Brazil). The area is subjected to landslide risk and the deployed system aims to provide subsidies to the authorities to prepare actions related to prevention and evacuation, and serve as the basis for a future early-warning system in the framework of the Civil Defense of Duque de Caxias. The system consists of a compact and rugged X-band GB-InSAR newly developed by Bradar, Brazil. The processing and monitoring methodology are proposed. Two campaigns, totaling six days, were carried out. The acquisitions of the first campaign occurred without rain. In the second campaign, rain events, varying from light to torrential rainfall, occurred for a period of time, in subsequent days, during the radar acquisitions. New insights on landslide dynamics are revealed. The monitoring data show that, approximately 10 h after heavy rainfall, the terrain movement on a slope reached 4 mm/h during ca. 5 to 8 h, resulting in velocities of 20 to 32 mm/day.
Auteurs: Karlus Alexander Câmara de Macedo;Fernanda Ledo G. Ramos;Clóvis Gaboardi;João Roberto Moreira;Fernanda Vissirini;Marcello Silva da Costa;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 03.-2017, volume: 10, issue:3, pages: 975 - 986
Editeur: IEEE
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» A Compact, Capacitively Fed UWB Antenna With Monopole-Like Radiation Characteristics
Résumé:
A compact, ultrawideband (UWB) antenna occupying a cylindrical volume and providing omnidirectional monopole-like radiation is introduced. The antenna consists of two closely placed 3-D loops, two parasitic small loops, and a circular top hat. Two strip-shaped probes, each coupling with one loop, are used to feed the antenna in common mode. UWB operation is achieved by taking advantage of the magnetic coupling of the parallel-fed 3-D loops. Small electrical dimensions of the antenna are due to the special capacitive proximity feeding scheme and the presence of the top hat. A prototype with 4.1:1 bandwidth is designed, fabricated, and characterized. The antenna demonstrates a VSWR better than 2:1 and monopole-like omnidirectional radiation characteristics across this entire band. It occupies a cylindrical volume with a diameter of $0.14lambda _{mathrm{min}}$ and a height of $0.09lambda _{mathrm{min}}$ , where $lambda _{mathrm{min}}$ is the free-space wavelength at the lowest frequency of operation. The antenna has a $k_{mathrm{min}}a = 0.73$ , where $k_{mathrm{min}}$ is the wavenumber at its lowest frequency of operation. The fabricated prototype is demonstrated to have a lowest frequency of operation that is only 10% above the theoretical limits on UWB antennas. Further miniaturization of the antenna using a spherical top hat is also examined and demonstrated to be capable of reducing $k_{mathrm{min}}a$ values down to 0.60.
Auteurs: Mingjian Li;Nader Behdad;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1026 - 1037
Editeur: IEEE
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» A Comparative Study of Metal–Semiconductor–Metal Ultraviolet Photodetectors Based on Ultrasonic Spray Pyrolysis Deposited Anatase and Rutile TiO2
Résumé:
Anatase and rutile TiO2-based metal–semiconductor–metal (MSM) ultraviolet photodetectors (PDs) are fabricated and investigated. The TiO2 thin films are grown by the ultrasonic spray pyrolysis deposition and the TiO2 films are annealed at 400 °C and 800 °C to form the anatase and the rutile phases. The material characteristics were measured by X-ray diffraction, Raman spectrum, X-ray photoelectron spectroscopy, and photoluminescence. The optical characteristics such as refractive index, extinction coefficient, absorption coefficient, and optical reflectance were characterized. The electrical and optoelectronic characteristics of the anatase and rutile TiO2 MSM PDs were characterized, including current-voltage, Schottky barrier height, spectral responsivity, response time, and detectivity.
Auteurs: Han-Yin Liu;Guan-Jyun Liu;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 1108 - 1113
Editeur: IEEE
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» A Comparison of Three Uniquely Different State of the Art and Two Classical Multiobjective Optimization Algorithms as Applied to Electromagnetics
Résumé:
This paper compares three modern and two classical multiobjective optimizers (MOOs) as applied to real-world problems in electromagnetics. The behavior of sophisticated optimizers on simple test functions has been studied exhaustively. In contrast, the algorithms here are tested on practical applications, where the function evaluations are computationally expensive, making the convergence rate a crucial factor. The examples considered include the optimization of a narrowband slot antenna, a mushroom-type electromagnetic bandgap structure, and an ultrawideband Vivaldi antenna. Another popular topic in the literature is in comparing classical MOOs on electromagnetics problems. The modern optimizers chosen in this paper are state of the art and each has a distinct design philosophy. This paper introduces two unique MOOs to the electromagnetics community: BORG, an auto-adaptive genetic algorithm and the Multi-Objective Covariance Matrix Adaptation Evolutionary Strategy (MO-CMA-ES), an extension of the popular single-objective CMA-ES. These algorithms are compared to the Multi-objective Evolutionary Algorithm based on Decomposition (MOEA/D), a Chebysheff scalarization algorithm, and two classical MOOs. This paper will study the behavior of these algorithms on problems in electromagnetics with a limited number of function evaluations using five distinct metrics and will provide useful guidelines and recommended optimizer settings.
Auteurs: Jogender Nagar;Douglas H. Werner;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1267 - 1280
Editeur: IEEE
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» A Comprehensive Characterization Method for Lateral Profiling of Interface Traps and Trapped Charges in P-SONOS Cell Devices
Résumé:
A comprehensive characterization method has been developed in this paper for reliable lateral profiling of the interface traps ( ${Delta {mathrm{ N}}_{mathrm{ it}}}$ ), localized charges ( ${Delta {mathrm{ N}}_{mathrm{ ot}}}$ ), and trapped holes ( ${Delta {mathrm{ N}}_{mathrm{ hole}}}$ ) in P-SONOS cell devices. Charge pumping current ( ${rm I_{mathrm{ CP}}} $ ) measurement can be used to probe ${Delta {mathrm{ N}}_{mathrm{ it}}}$ and ${Delta {mathrm{ N}}_{mathrm{ ot}}} $ from the increase of maximum ${rm I_{mathrm{ CP}};({mathrm{ I}}_{rm CP,{mathrm{ max}}} )}$ and the shift of ${rm I_{mathrm{ CP}}} $ curve along the base level voltage ( ${rm V_{mathrm{ b}}} $ ). When increasing the program and erase (P/E) cycles, the negative threshold voltage ( ${rm V_{mathrm{ T}}} $ ) shift at both program and erase states suggests the generation of ${Delta {mathrm{ N}}_{mathrm{ hole}}}$ . The evolution of ${Delta {mathrm{ N}}_{mathrm{ it}}} $ , ${Delta {mathrm{ N}}_{mathrm{ ot}}} $ , and ${Delta {mathrm{ N}}_{mathrm{ hole}}}$ during P/E cycling can consistently explain the nonmonotonic variations of gate induced drain leakage current ( ${rm I_{mathrm{ GIDL}}}$ ) and substrate current ( ${rm I_{mathrm{ SUB}}}$ ) as well as dramatic differences between the source and drain. The lateral migration of ${Delta {mathrm{ N}}_{mathrm{ ot}}}$ caused by extending P/E cycles may lead to the failure of two-bit operation in SONOS cell devices. The larger ${rm V_{mathrm{ T}}}$ shift and subthreshold swing, smaller read current, and lower transconductance may degrade the endurance and retention of P-SONOS when applied in Flash memory.
Auteurs: Jyh-Chyurn Guo;Pei-Ying Du;
Apparue dans: IEEE Transactions on Device and Materials Reliability
Date publication: 03.-2017, volume: 17, issue:1, pages: 121 - 129
Editeur: IEEE
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» A Comprehensive Study of MapReduce Over Lustre for Intermediate Data Placement and Shuffle Strategies on HPC Clusters
Résumé:
With high performance interconnects and parallel file systems, running MapReduce over modern High Performance Computing (HPC) clusters has attracted much attention due to its uniqueness of solving data analytics problems with a combination of Big Data and HPC technologies. Since the MapReduce architecture relies heavily on the availability of local storage media, the Lustre-based global storage in HPC clusters poses many new opportunities and challenges. In this paper, we perform a comprehensive study on different MapReduce over Lustre deployments and propose a novel high-performance design of YARN MapReduce on HPC clusters by utilizing Lustre as the additional storage provider for intermediate data. With a deployment architecture where both local disks and Lustre are utilized for intermediate data storage, we propose a novel priority directory selection scheme through which RDMA-enhanced MapReduce can choose the best intermediate storage during runtime by on-line profiling. Our results indicate that, we can achieve 44 percent performance benefit for shuffle-intensive workloads in leadership-class HPC systems. Our priority directory selection scheme can improve the job execution time by 63 percent over default MapReduce while executing multiple concurrent jobs. To the best of our knowledge, this is the first such comprehensive study for YARN MapReduce with Lustre and RDMA.
Auteurs: Md. Wasi-ur- Rahman;Nusrat Sharmin Islam;Xiaoyi Lu;Dhabaleswar K. (DK) Panda;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 03.-2017, volume: 28, issue:3, pages: 633 - 646
Editeur: IEEE
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» A Comprehensive Study on the Geometrical Effects in High-Power 4H–SiC BJTs
Résumé:
Geometrical effects on the forward characteristics of high-power bipolar junction transistors are studied. An implantation-free area optimized junction termination is implemented in order to have a stable breakdown voltage. The effect of varying the emitter-base geometry, i.e., the emitter width ( W_{E}) , the base width ( W_{B}) , emitter contact–emitter edge distance ( W_{n}) , and base contact–emitter edge ( W_{p}) on the on-state characteristics is studied in the different emitter cell geometries. The emitter size effect shows the highest influence on the current gain ( \beta ) . It shows a significant effect on the \beta (single finger design, about 61%; square cell geometry, about 98%; hexagon cell geometry, about 90%). The base size effect also shows a significant improvement on the \beta of about 23% at a given W_{E} .
Auteurs: Arash Salemi;Hossein Elahipanah;Carl-Mikael Zetterling;Mikael Östling;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 882 - 887
Editeur: IEEE
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» A Consensus-Based Approach for Platooning with Intervehicular Communications and Its Validation in Realistic Scenarios
Résumé:
Automated and coordinated vehicles' driving (platooning) is very challenging due to the multibody control complexity and the presence of unreliable time-varying wireless intervehicular communication (IVC). We propose a novel controller for vehicle platooning based on consensus and analytically demonstrate its stability and dynamic properties. Traditional approaches assume the logical control topology as a constraint fixed a priori, and the control law is designed consequently; our approach makes the control topology a design parameter that can be exploited to reconfigure the controller, depending on the needs and characteristics of the scenario. Furthermore, the controller automatically compensates outdated information caused by network losses and delays. The controller is implemented in Plexe, which is a state-of-the-art IVC and mobility simulator that includes basic building blocks for platooning. Analysis and simulations show the controller robustness and performance in several scenarios, including realistic propagation conditions with interference caused by other vehicles. We compare our approach against a controller taken from the literature, which is generally considered among the most performing ones. Finally, we test the proposed controller by implementing the real dynamics (engine, transmission, braking systems, etc.) of heterogeneous vehicles in Plexe and verifying that platoons remain stable and safe, regardless of real-life impairments that cannot be modeled in the analytic solution. The results show the ability of the proposed approach to maintain a stable string of realistic vehicles with different control-communication topologies, even in the presence of strong interference, delays, and fading conditions, providing higher comfort and safety for platoon drivers.
Auteurs: Stefania Santini;Alessandro Salvi;Antonio Saverio Valente;Antonio Pescapé;Michele Segata;Renato Lo Cigno;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 03.-2017, volume: 66, issue:3, pages: 1985 - 1999
Editeur: IEEE
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» A Controllable Power Distribution Strategy for Open Winding Hybrid Excitation Generator System
Résumé:
The open winding permanent magnet generator system is suitable for applications such as renewable energy power generation systems with multiple power sources, due to its high power density, relatively few power switches, and high degree of integration. However, for this system, it is difficult to quantitatively control the power distribution between different energy sources. In this paper, an open winding hybrid excitation generator system is presented, and for this system, a controllable power distribution strategy is investigated. In the proposed strategy, the excitation current is regulated according to the error in the current loop of the auxiliary energy source, which can achieve the regulation of the output power of the generator and finally realize the power quantitative control of the auxiliary energy source. Then, the topologies of the hybrid excitation machine are analyzed and chosen with emphasize on the influence of the flux regulation capability on the control capability of system power distribution. The experiments are carried out on a parallel hybrid excitation flux-switching (PHEFS) generator system, and the results verify the correctness and effectiveness of the proposed controllable power distribution strategy and the power distribution capability of the PHEFS generator.
Auteurs: Yu Wang;Zhiquan Deng;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 122 - 136
Editeur: IEEE
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» A Conversation About Signal Processing at Elementary School [From the Editor]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Min Wu;
Apparue dans: IEEE Signal Processing Magazine
Date publication: 03.-2017, volume: 34, issue:2, pages: 3 - 4
Editeur: IEEE
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» A Conversation with Your Future Self [From the Editor's Desk]
Résumé:
Presents the introductory editorial for this issue of the publication.
Auteurs: Lanny Floyd;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 03.-2017, volume: 23, issue:2, pages: 3 - 3
Editeur: IEEE
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» A Convolutional Neural Network-Based Chinese Text Detection Algorithm via Text Structure Modeling
Résumé:
Text detection in a natural environment plays an important role in many computer vision applications. While existing text detection methods are focused on English characters, there are strong application demands on text detection in other languages, such as Chinese. In this paper, we present a novel text detection algorithm for Chinese characters based on a specific designed convolutional neural network (CNN). The CNN contains a text structure component detector layer, a spatial pyramid layer, and a multi-input-layer deep belief network (DBN). The CNN is pre-trained via a convolutional sparse auto-encoder, specifically designed for extracting complex features from Chinese characters. In particular, the text structure component detectors enhance the accuracy and uniqueness of feature descriptors by extracting multiple text structure components in various ways. The spatial pyramid layer enhances the scale invariability of the CNN for detecting texts in multiple scales. Finally, the multi-input-layer DBN replaces the fully connected layers in the CNN to ensure features from multiple scales are comparable. A multilingual text detection dataset, in which texts in Chinese, English, and digits are labeled separately, is set up to evaluate the proposed text detection algorithm. The proposed algorithm shows a significant performance improvement over the baseline CNN algorithms. In addition the proposed algorithm is evaluated over a public multilingual benchmark and achieves state-of-the-art result under multiple languages. Furthermore, a simplified version of the proposed algorithm with only general components is evaluated on the ICDAR 2011 and 2013 datasets, showing comparable detection performance to the existing general text detection algorithms.
Auteurs: Xiaohang Ren;Yi Zhou;Jianhua He;Kai Chen;Xiaokang Yang;Jun Sun;
Apparue dans: IEEE Transactions on Multimedia
Date publication: 03.-2017, volume: 19, issue:3, pages: 506 - 518
Editeur: IEEE
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» A DC-to-12.5 Gb/s 9.76 mW/Gb/s All-Rate CDR With a Single LC VCO in 90 nm CMOS
Résumé:
A dual-lane DC-to-12.5 Gb/s all-rate clock and data recovery (CDR) IC with a single LC voltage-controlled oscillator is fabricated in a 90 nm CMOS. An all-rate clock divider with an asynchronous phase calibration scheme is employed to generate all-rate clock signals without a phase mismatch or duty cycle distortion. The IC features an automatic loop gain control scheme that adjusts the bandwidth of a CDR in the background for optimal bit error rate (BER) performance by monitoring the phase difference between the incoming data and the recovered clock signal. The proposed CDR consumes 244 mW at 12.5 Gb/s under dual-lane operation with an input sensitivity of 12 mV $_{mathrm { {pp,diff}}}$ . The CDR supports referenceless all-rate operation with a BER < 10 $^{mathrm { {-12}}}$ on PRBS31 and compensates for 20 dB of channel loss using a continuous-time linear equalizer (CTLE), a one-tap decision feedback equalizer (DFE), and a three-tap pre-emphasis filter. The power efficiency of the test chip is 9.76 mW/Gb/s.
Auteurs: Jong-Hyeok Yoon;Soon-Won Kwon;Hyeon-Min Bae;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 856 - 866
Editeur: IEEE
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» A Declarative Optimization Engine for Resource Provisioning of Scientific Workflows in Geo-Distributed Clouds
Résumé:
Geo-distributed clouds are becoming increasingly popular for cloud providers, and data centers with different regions often offer different prices, even for the same type of virtual machines. Resource provisioning in geo-distributed clouds is an important and complicated problem for budget and performance optimizations of scientific workflows. Scientists are facing the complexities resulted from various cloud offerings in the geo-distributed settings, severe cloud performance dynamics and evolving user requirements on performance and cost. To address those complexities, we propose a declarative optimization engine named Geco for resource provisioning of scientific workflows in geo-distributed clouds. Geco allows users to specify their workflow optimization goals and constraints of specific problems with an extended declarative language. We propose a novel probabilistic optimization approach for evaluating the declarative optimization goals and constraints to address the cloud dynamics. Additionally, we develop runtime optimizations to more effectively utilize the cloud resources at runtime. To accelerate the solution finding, Geco leverages the power of GPUs to find the solution in a fast and timely manner. Our evaluations with four common workflow provisioning problems demonstrate that, Geco is able to achieve more effective performance/cost optimizations in geo-distributed cloud environments than the state-of-the-art approaches.
Auteurs: Amelie Chi Zhou;Bingsheng He;Xuntao Cheng;Chiew Tong Lau;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 03.-2017, volume: 28, issue:3, pages: 647 - 661
Editeur: IEEE
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» A Deep Matrix Factorization Method for Learning Attribute Representations
Résumé:
Semi-Non-negative Matrix Factorization is a technique that learns a low-dimensional representation of a dataset that lends itself to a clustering interpretation. It is possible that the mapping between this new representation and our original data matrix contains rather complex hierarchical information with implicit lower-level hidden attributes, that classical one level clustering methodologies cannot interpret. In this work we propose a novel model, Deep Semi-NMF, that is able to learn such hidden representations that allow themselves to an interpretation of clustering according to different, unknown attributes of a given dataset. We also present a semi-supervised version of the algorithm, named Deep WSF, that allows the use of (partial) prior information for each of the known attributes of a dataset, that allows the model to be used on datasets with mixed attribute knowledge. Finally, we show that our models are able to learn low-dimensional representations that are better suited for clustering, but also classification, outperforming Semi-Non-negative Matrix Factorization, but also other state-of-the-art methodologies variants.
Auteurs: George Trigeorgis;Konstantinos Bousmalis;Stefanos Zafeiriou;Björn W. Schuller;
Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence
Date publication: 03.-2017, volume: 39, issue:3, pages: 417 - 429
Editeur: IEEE
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» A Depth From Defocus Measurement System Using a Liquid Lens Objective for Extended Depth Range
Résumé:
A novel depth from defocus (DFD) measurement system is presented, where the extension of the measurement range is performed using an emergent technology based on liquid lenses. A suitable set of different focal lengths, obtained by properly changing the liquid lens supply voltage, provides multiple camera settings without duplicating the system elements or using moving parts. A simple and compact setup, with a single camera/illuminator coaxial assembly, is obtained. The measurement is based on an active DFD technique using modulation measurement profilometry for the estimation of the contrast at each image point as a function of the depth range. Two different measurement methods are proposed, both based on a combination of multiple contrast curves, each derived at a specific focal length. In the first method (intensity contrast method), the depth information is recovered directly from the contrast curves, whereas in the second (differential contrast method), the depth is measured using contrast curve pairs. We obtained a measurement \sigma _{{{0}}} of 0.55 mm over a depth range of 60 mm with the intensity contrast method (0.92% of the total range) and an \sigma _{{{0}}} of 0.76 mm over a depth range of 135 mm with the differential contrast method (0.56% of the total range). Thus, the intensity contrast method is within the state-of-the-art DFD systems, whereas the differential contrast method allows, \sigma _{{{0}}} being almost equal, a remarkable extension of the depth range.
Auteurs: Simone Pasinetti;Ileana Bodini;Matteo Lancini;Franco Docchio;Giovanna Sansoni;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 03.-2017, volume: 66, issue:3, pages: 441 - 450
Editeur: IEEE
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» A Diamond Milestone for a Winning Combination
Résumé:
Auteurs: George F. Hayhoe;
Apparue dans: IEEE Transactions on Professional Communication
Date publication: 03.-2017, volume: 60, issue:1, pages: 2 - 3
Editeur: IEEE
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» A Displacement Uncertainty Model for 2-D DIC Measurement Under Motion Blur Conditions
Résumé:
In this paper, the effects of motion blur on 2-D digital image correlation (DIC) measurements are discussed, with a particular focus on the description of displacement measurement uncertainty. The research started with the simulation of motion blur with a suitable literature-based algorithm. Then the state of the art of uncertainty analysis in the context of DIC was compared with simulation results, and it was found that the effects of motion blur on uncertainty are not predicted correctly by the literature models. This phenomenon is explained by the fact that the literature models do not consider motion blur. Consequently, a simple monodimensional case is analyzed. In this way, it has been possible to evaluate the sensitivity of DIC correlation function [evaluated as the sum of squared differences (SSD)] to motion blur. Using these results, it is possible to extend the analysis to the case of a generic image with the help of a power-law model. Eventually, the model proposed in this paper is able to represent the effects of motion blur correctly.
Auteurs: Alberto Lavatelli;Emanuele Zappa;
Apparue dans: IEEE Transactions on Instrumentation and Measurement
Date publication: 03.-2017, volume: 66, issue:3, pages: 451 - 459
Editeur: IEEE
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» A Distributed Feedback Motion Planning Protocol for Multiple Unicycle Agents of Different Classes
Résumé:
This paper presents a novel feedback method for the motion planning and coordination of multiple agents that belong to two classes, namely class-A and class-B. All agents are modeled via unicycle kinematics. Agents of class-B do not share information with agents of class-A and do not participate in ensuring safety, modeling thus agents with failed sensing/communication systems, agents of higher priority, or moving obstacles with known upper bounded velocity. The method is built upon a family of 2-D analytic vector fields, which under mild assumptions are proved to be safe feedback motion plans with a unique stable singular point. The conditions which ensure collision free and almost global convergence for a single agent and the analytical form of the vector fields are then utilized in the design the proposed distributed, semi-cooperative multi-agent coordination protocol. Semi-cooperative coordination has been defined in prior work as the ad hoc prioritization and conflict resolution among agents of the same class; more specifically, participation in conflict resolution and collision avoidance for each agent is determined on-the-fly based on whether the agent's motion results in decreasing its distance with respect to its neighbor agents; based on this condition, the agent decides to either ignore its neighbors, or adjust its velocity and avoid the neighbor agent with respect to which the rate of decrease of the pairwise inter agent distance is maximal. The proposed coordination protocol builds upon this logic and addresses the case of multiple agents of distinct classes (class-A and class-B) in conflict. Guarantees on the safety of the multi-agent system and the almost global convergence of the agents to their destinations are proved. The efficacy of the proposed methodology is demonstrated via simulation results in static and dynamic environments.
Auteurs: Dimitra Panagou;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 03.-2017, volume: 62, issue:3, pages: 1178 - 1193
Editeur: IEEE
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» A Dual Method for Computing Power Transfer Distribution Factors
Résumé:
Power Transfer Distribution Factors (PTDFs) play a crucial role in power grid security analysis, planning, and redispatch. Fast calculation of the PTDFs is therefore of great importance. In this paper, we present a non-approximative dual method of computing PTDFs. It uses power flows along topological cycles of the network but still relies on simple matrix algebra. At the core, our method changes the size of the matrix that needs to be inverted to calculate the PTDFs from N\times N , where N is the number of buses, to (L-N+1)\times (L-N+1) , where L is the number of lines and L-N+1 is the number of independent cycles (closed loops) in the network while remaining mathematically fully equivalent. For power grids containing a relatively small number of cycles, the method can offer a speedup of numerical calculations.
Auteurs: Henrik Ronellenfitsch;Marc Timme;Dirk Witthaut;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1007 - 1015
Editeur: IEEE
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» A Dynamic Real Option-Based Investment Model for Renewable Energy Portfolios
Résumé:
This work proposes a dynamic model to devise the optimal risk-averse investment policy in a portfolio of complementary renewable sources for a generation company in the Brazilian power system. The proposed method merges a static energy-contracting model, based on a hybrid robust-and-stochastic optimization approach, with a mean reverting binomial lattice model for real-option valuation. The proposed merge extends previous works by providing support to risk-averse investment decisions in complementary renewable sources dynamically distributed over time. The most important results of the model are: how much capacity to invest or build from each renewable source, how much to sell from the energy portfolio in bilateral contracts, and the optimal timing to invest. Unlike previous reported works, our model takes into account three classes of uncertainties simultaneously: renewable production of candidate sources and prices in the spot and contract markets. A case study with realistic data from the Brazilian power system is presented to illustrate the value of our model.
Auteurs: Aderson Campos Passos;Alexandre Street;Luiz Augusto Barroso;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 883 - 895
Editeur: IEEE
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» A Fast Process-Variation-Aware Mask Optimization Algorithm With a Novel Intensity Modeling
Résumé:
With the continuous shrinkage of advanced technology nodes into the sub-16-nm regime, optical proximity correction (OPC) is still the main stream to preserve acceptable wafer image quality under lithographic process variations in the foreseeable future. However, OPC is getting more aggressive to keep pace with advanced technology nodes. This results in complex mask solutions and long computation time. In this paper, we propose a novel-intensity-based OPC algorithm to find mask solutions with minimal edge placement error and process variability band area within a short computation time. This is achieved through exploiting a fast novel intensity estimation model with acceptable estimation accuracy to guide the OPC response including two-fragment shifting, corner hammering, and subresolution assist feature insertion for better convergence. Moreover, our algorithm is extended to satisfy the mask notch rule and reduce shot count for a lower mask manufacturing cost. The experimental results show that our algorithm outperforms recently published algorithms on the public benchmarks.
Auteurs: Ahmed Awad;Atsushi Takahashi;Satoshi Tanaka;Chikaaki Kodama;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 998 - 1011
Editeur: IEEE
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» A Faster Algorithm for Enumerating Connected Convex Subgraphs in Acyclic Digraphs
Résumé:
Subgraph enumeration is one of the most crucial steps involved in the custom instruction identification for application-specific instruction set processors. Generating all connected convex subgraphs from an acyclic digraph is a computationally difficult problem. In this letter, we propose a simple and fast algorithm for enumerating all connected convex subgraphs in acyclic digraphs. Experimental results show that our algorithm outperforms the latest algorithm in the literature. We also present a parallel approach for enumerating all connected convex subgraphs using MapReduce. Results for real world benchmarks covering different application domains reveal that the parallel approach can achieve near linear speedup over the sequential approach.
Auteurs: Shanshan Wang;Chenglong Xiao;Wanjun Liu;
Apparue dans: IEEE Embedded Systems Letters
Date publication: 03.-2017, volume: 9, issue:1, pages: 9 - 12
Editeur: IEEE
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» A Fault-Diagnosis and Fault-Tolerant Control Scheme for Flying Capacitor Multilevel Inverters
Résumé:
The high number of power semiconductors in multilevel converters makes them susceptible to failure. Therefore, one of the main concerns in utilizing multilevel inverters is their reliability. This paper proposes a new simple fault-diagnosis and fault-handling method to increase the robustness and reliability of a flying capacitor multilevel inverter (FCMLI) which is one of the most prominent multilevel inverters. The proposed method is capable of diagnosing failed switch(es) and reconfiguring the switching sequence such that the output voltage is maintained similar to a normal operation condition. The proposed scheme identifies failed switch(es) by using the information about the charging state of the capacitors and the applied switching sequence. After identifying the failed switch(es), the algorithm bypasses the failed switch(es) and converts the control signals of the faulty leg from an M -cell L-level configuration to an (M-F)-cell L -level configuration (where F is the number of failed switches). The most attractive feature of the proposed control scheme is that any number of failed switches can be tolerated, as long as the number of functional switches is higher than the minimum number of cells required to build a full-binary L-level FCMLI. Simulation and experimental results are presented that verify the effectiveness of the proposed method.
Auteurs: Jalal Amini;Mehrdad Moallem;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 1818 - 1826
Editeur: IEEE
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» A Ferroelectric Nonvolatile Processor with 46 $mu $ s System-Level Wake-up Time and 14 $mu $ s Sleep Time for Energy Harvesting Applications
Résumé:
Nonvolatile processor (NVP) attracts more and more attentions for its immunity to power loss in energy harvesting scenarios. The overall performance of an NVP is determined by its sleep and wake-up speeds, which refer to how fast the NVP can turn itself off and on when a sudden power failure occurs. To the best of our knowledge, this paper is the first work to improve the system-level sleep/wake-up speed of an energy harvesting NVP. A hybrid CMOS/ferroelectric nonvolatile flip-flop (nvFF) and a high-speed voltage detector are designed and integrated in the proposed NVP to jointly minimize its sleep and wake-up time. Measurement results demonstrate 46~\mu text {s} wake-up time and 14~\mu text {s} sleep time, which is up to 18 and 24 times speedup over existing works. This approach not only improves the robustness of the NVP to power fluctuations but also brings significant advantages for better utilization of harvested energy.
Auteurs: Fang Su;Yongpan Liu;Yiqun Wang;Huazhong Yang;
Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers
Date publication: 03.-2017, volume: 64, issue:3, pages: 596 - 607
Editeur: IEEE
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» A Flexible Continuous-Time $Delta Sigma $ ADC With Programmable Bandwidth Supporting Low-Pass and Complex Bandpass Architectures
Résumé:
A flexible continuous-time \Delta \Sigma modulator that supports both low-pass and complex bandpass (CBP) architectures with the programmable bandwidths of 5 and 10 MHz is presented. By utilizing flexibility into both architectural level and core building blocks, scalable power consumption is obtained for each mode with desired performance. An amplifier topology with active feedforward, antipole splitting, and current reuse techniques is proposed for effective power reduction. A prototyped \Delta \Sigma modulator in a 65-nm CMOS achieves a 65.1-/62.2-dB peak signal-to-noise-plus-distortion ratio (SNDR) with a 5-/10-MHz bandwidth in the LP architecture and a 62.9-/64.1-dB SNDR over a 5-/10-MHz signal band with a tunable center frequency of 4–6 MHz in the CBP architecture, respectively. The figure of merit is 0.21/0.23/0.36/0.24 pJ/conversion step for each mode with a power consumption of 3.1/4.8/4.2/6.3 mW by a 1.2 V supply voltage. The dynamic range is 73/65.8/74.3/74.2 dB. The active area is 0.39 mm2.
Auteurs: Yang Xu;Xinwang Zhang;Zhihua Wang;Baoyong Chi;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 872 - 880
Editeur: IEEE
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» A Flexible Voltage Bus Converter for the 48-/12-V Dual Supply System in Electrified Vehicles
Résumé:
Due to an increasing in-vehicle electric load demand, a new 48-V electric system architecture proposed by German premier car manufacturers has been gaining increasing attention recently for electrified vehicles. In this paper, a multiple-voltage bus converter for the 48-V and existing 12-V dual supply system, providing additional flexible dc bus voltages, is proposed. The proposed converter can provide a dual flexible dc voltage bus and an additional dependent voltage bus while simultaneously managing the 12-V supply net using only one single-leg switch pole and a diode. The additional dc voltage buses will provide more options to accommodate variable electric load components in a vehicle, improving their power density. Due to the multiple control objectives, the single-leg pole requires a multimode switching strategy to regulate the additional bus voltages. To improve the onboard vehicle system reliability and performance, an impedance network structure is implemented in the converter to obtain a dead-time-free pulsewidth modulation (PWM). Simulation and experimental results are presented to verify the feasibility and effectiveness of the proposed structure and control method.
Auteurs: Taehyung Kim;Sangshin Kwak;
Apparue dans: IEEE Transactions on Vehicular Technology
Date publication: 03.-2017, volume: 66, issue:3, pages: 2010 - 2018
Editeur: IEEE
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» A Flow-Level Extension to OMNeT++ for Long Simulations of Large Networks
Résumé:
This letter presents a Flow-Level Extension to OMNeT++ (FLEO) that allows a discrete event simulator to operate on flows of traffic, and so simulate larger networks for longer periods of time for a given set of computation and memory resources compared with packet-based simulation. FLEO simulations of link utilization are accurate to within 0.2% of a packet-based simulation, yet run 30 to 90 times faster than packet-based simulation. These characteristics make it suitable for the simulation of streaming media, which comprises the majority of data usage today, as well as investigation of traffic engineering within a network, for example, using software-defined networking.
Auteurs: Gilbert Anggono;Tim Moors;
Apparue dans: IEEE Communications Letters
Date publication: 03.-2017, volume: 21, issue:3, pages: 496 - 499
Editeur: IEEE
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» A Framework for Robust Assessment of Power Grid Stability and Resiliency
Résumé:
Security assessment of large-scale, strongly nonlinear power grids containing thousands to millions of interacting components is a computationally expensive task. Targeting at reducing the computational cost, this paper introduces a framework for constructing a robust assessment toolbox that can provide mathematically rigorous certificates for the grids’ stability in the presence of variations in power injections, and for the grids’ ability to withstand a bunch sources of faults. By this toolbox we can “offline” screen a wide range of contingencies or power injection profiles, without reassessing the system stability on a regular basis. In particular, we formulate and solve two novel robust stability and resiliency assessment problems of power grids subject to the uncertainty in equilibrium points and uncertainty in fault-on dynamics. Furthermore, we bring in the quadratic Lyapunov functions approach to transient stability assessment, offering real-time construction of stability/resiliency certificates and real-time stability assessment. The effectiveness of the proposed techniques is numerically illustrated on a number of IEEE test cases.
Auteurs: Thanh Long Vu;Konstantin Turitsyn;
Apparue dans: IEEE Transactions on Automatic Control
Date publication: 03.-2017, volume: 62, issue:3, pages: 1165 - 1177
Editeur: IEEE
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» A Frequency Stable Volume Integral Equation Method for Anisotropic Scatterers
Résumé:
We introduce a volume integral equation method for the numerical solution of the electromagnetic scattering problem from electrically anisotropic inhomogeneous objects. The problem’s unknown, that is the sum of the conduction and polarization current densities, is decomposed in terms of its loop, star and facet components. Suitable strategies have been implemented to enforce the uniqueness of this discrete representation. Furthermore, through a convenient scaling of the unknowns, we also make the present method immune to the low-frequency breakdown problem, showing its stability regardless of the operating frequency. This approach has been extensively validated against the null-field method by analyzing the scattering from a uniaxial dielectric sphere and a uniaxial dielectric slab and comparing the scattered electric field in both the near and far zones. The condition number of the scattering problem consisting of a slab with an assigned conductivity tensor is also monitored as a function of the exciting frequency.
Auteurs: Carlo Forestiere;Giovanni Miano;Guglielmo Rubinacci;Antonello Tamburrino;Lalita Udpa;Salvatore Ventre;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1224 - 1235
Editeur: IEEE
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» A Frequency-Shift Method to Measure Shear-Wave Attenuation in Soft Tissues
Résumé:
In vivo quantification of shear-wave attenuation in soft tissues may help to better understand human tissue rheology and lead to new diagnostic strategies. Attenuation is difficult to measure in acoustic radiation force elastography because the shear-wave amplitude decreases due to a combination of diffraction and viscous attenuation. Diffraction correction requires assuming a cylindrical wavefront and an isotropic propagation medium, which may not be the case in some applications. In this paper, the frequency-shift method, used in ultrasound imaging and seismology, was adapted for shear-wave attenuation measurement in elastography. This method is not sensitive to diffraction effects. For a linear frequency dependence of the attenuation, a closed-form relation was obtained between the decrease in the peak frequency of the gamma-distributed wave amplitude spectrum and the attenuation coefficient of the propagation medium. The proposed method was tested against a plane-wave reference method in homogeneous agar–gelatin phantoms with 0%, 10%, and 20% oil concentrations, and hence different attenuations of 0.117, 0.202, and 0.292 $text {Np}cdot text {m}^{-1}$ /Hz, respectively. Applicability to biological tissues was demonstrated with two ex vivo porcine liver samples (0.79 and 1.35 $text {Np} ,cdot , text {m}^{-1}$ /Hz) and an in vivo human muscle, measured along (0.43 $text {Np},cdot , text {m}^{-1}$ /Hz) and across (1.77 $text {Np}cdot text {m}^{-1}$ /Hz) the tissue fibers. In all cases, the data supported the assumptions of a gamma-distributed spectrum for the- source and linear frequency attenuation for the tissue. This method provides tissue attenuation, which is relevant diagnostic information to model viscosity, in addition to shear-wave velocity used to assess elasticity. Data processing is simple and could be performed automatically in real time for clinical applications.
Auteurs: Simon Bernard;Siavash Kazemirad;Guy Cloutier;
Apparue dans: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Date publication: 03.-2017, volume: 64, issue:3, pages: 514 - 524
Editeur: IEEE
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» A Frog-Shaped Linear Piezoelectric Actuator Using First-Order Longitudinal Vibration Mode
Résumé:
A frog-shaped linear piezoelectric actuator was proposed, designed, fabricated, and tested. The proposed actuator only used the first-order longitudinal vibration to generate linear motion, which made the design, optimization, and miniaturization of the actuator more flexible by abbreviating the frequency degeneration. By stimulating the first-order longitudinal vibration, alternate oblique movements are formed on the ends of two driving feet. Meanwhile, an elongating and shortening movement of the whole actuator is generated. When two parallel walls are in contact with the ends of two diving feet and a vertical preload is applied, the vertical components of the alternate oblique movements will overcome the preload, while the horizontal components of the alternate oblique movements and the elongating and shortening movements will together push the actuator into linear motion. Vibration characteristics and alternate oblique movements of the driving feet were investigated by the finite-element method. Experiment tests of vibration characteristics and mechanical output ability were then carried out. The tested resonance frequency and vibration amplitudes agreed well with the calculated ones. The prototype achieved a maximum speed and a thrust of 287 mm/s and 11.8 N, respectively.
Auteurs: Qiang Zhang;Weishan Chen;Yingxiang Liu;Junkao Liu;Qiang Jiang;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 2188 - 2195
Editeur: IEEE
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» A Fully Integrated Reconfigurable Self-Startup RF Energy-Harvesting System With Storage Capability
Résumé:
This paper introduces a fully integrated RF energy-harvesting system. The system can simultaneously deliver the current demanded by external dc loads and store the extra energy in external capacitors, during periods of extra output power. The design is fabricated in 0.18- $mu text{m}$ CMOS technology, and the active chip area is 1.08 mm2. The proposed self-startup system is reconfigurable with an integrated LC matching network, an RF rectifier, and a power management/controller unit, which consumes 66–157 nW. The required clock generation and the voltage reference circuit are integrated on the same chip. Duty cycle control is used to operate for the low input power that cannot provide the demanded output power. Moreover, the number of stages of the RF rectifier is reconfigurable to increase the efficiency of the available output power. For high available power, a secondary path is activated to charge an external energy storage element. The measured RF input power sensitivity is −14.8 dBm at a 1-V dc output.
Auteurs: Mohamed A. Abouzied;Krishnan Ravichandran;Edgar Sánchez-Sinencio;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 704 - 719
Editeur: IEEE
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» A Game-Theoretical Analysis of Wireless Markets Using Network Aggregation
Résumé:
Modeling wireless access and spectrum markets is challenging due to a plethora of technological and economic aspects that affect their performance. This work develops a modeling framework for analysing such markets using network economics, game theory, and queueing networks. The framework models the service selection of users as well as the competition and coalition among providers. It also develops tools and algorithms to analytically compute the Nash equilibriums (NEs) under the presence of discontinuities in the derivatives of the utility functions of providers. The analysis of different market scenarios reveals various interesting trends in the offered prices, market share, and revenue of providers depending on the user utility function, traffic demand, and mobility pattern. It also demonstrates the role of the quality of service (QoS) in the user utility function in reducing the intensity of competition and allowing for higher prices and revenue. However, the analysis of large-scale markets exhibits a high computational complexity. To improve the computational efficiency, we developed a network aggregation methodology based on the theorem of Norton. This aggregation allows the construction of equivalent networks for a specific region of interest, omitting the details of the entire networks. We demonstrate the aggregation algorithm in the context of capacity planning.
Auteurs: Georgios Fortetsanakis;Ioannis Dimitriou;Maria Papadopouli;
Apparue dans: IEEE Transactions on Mobile Computing
Date publication: 03.-2017, volume: 16, issue:3, pages: 602 - 616
Editeur: IEEE
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» A Gaussian Beam Approximation Approach for Embedding Antennas Into Vector Parabolic Equation-Based Wireless Channel Propagation Models
Résumé:
Vector parabolic equation (VPE) methods have been widely applied to the modeling of radio-wave propagation in tunnel environments, offering high computational efficiency and fidelity. While the propagation environment can be discretized and represented in detail, the representation of radiating sources (such as transmitting antennas) requires the calculation, analytical if possible or numerical via another method such as ray-tracing (RT), of the fields that the sources generate on the initial plane of the VPE model. These initial conditions are necessary for subsequently applying VPE. However, the solutions offered so far compromise either the accuracy or the efficiency of VPE. For example, generating the initial conditions for VPE through RT adds significant computational overhead to the typically fast VPE solver. To address this significant limitation of VPE methods, we introduce a technique that allows one to directly embed antennas into a VPE mesh, via a Gaussian beam approximation of their radiated fields. Hence, the initial conditions for VPE are generated for practical antenna patterns, without invoking other techniques and with no compromise on the inherent efficiency of VPE. Concrete guidelines on how to choose parameters for Gaussian beams are provided. Numerical results are compared to experimental measurements in various tunnel scenarios, demonstrating the validity and usefulness of the technique.
Auteurs: Xingqi Zhang;Costas D. Sarris;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1301 - 1310
Editeur: IEEE
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» A General Construction for PMDS Codes
Résumé:
Partial MDS [(PMDS) also known as maximally recoverable] codes allow for local erasure recovery by utilizing row-wise parities and additional erasure correction through global parities. Recent works on PMDS codes focus on special case parameter settings, and a general construction for PMDS codes is stated as an open problem. This letter provides an explicit construction for PMDS codes for all parameters utilizing concatenation of Gabidulin and MDS codes, a technique originally proposed by Rawat et al. for constructing optimal locally repairable codes. This approach allows for PMDS constructions for any parameters albeit with large field sizes. To lower the field size, a relaxation on the rate requirement is considered, and PMDS codes based on combinatorial designs are constructed.
Auteurs: Gokhan Calis;O. Ozan Koyluoglu;
Apparue dans: IEEE Communications Letters
Date publication: 03.-2017, volume: 21, issue:3, pages: 452 - 455
Editeur: IEEE
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» A Geometric Programming to Importance Sampling for Power System Reliability Evaluation
Résumé:
A novel Geometric Programming (GP) is presented in the first time by the optimization model of importance sampling parameters (ISP) in Variance Minimization (VM) for importance sampling (IS) of power system reliability evaluation. The key point of the proposed method is that the equality constraints of VM optimization model can be relaxed into inequalities because of its special structure, thus a new GP-VM convex optimization model can be built exactly to solve the difficulty of obtaining the optimal ISP. Numerical results of two test systems verify the effectiveness of the proposed method.
Auteurs: Chao Yan;Tao Ding;Zhaohong Bie;Xifan Wang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1568 - 1569
Editeur: IEEE
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» A GPU-Based Processing Chain for Linearly Unmixing Hyperspectral Images
Résumé:
Linear spectral unmixing is one of the nowadays hottest research topics within the hyperspectral imaging community, being a proof of this fact the vast amount of papers that can be found in the scientific literature about this challenging task. A subset of these works is devoted to the acceleration of previously published unmixing algorithms for application under tight time constraints. For this purpose, hyperspectral unmixing algorithms are typically implemented onto high-performance computing architectures in which the operations involved are executed in parallel, which conducts to a reduction in the time required for unmixing a given hyperspectral image with respect to the sequential version of these algorithms. The speedup factors that can be achieved by means of these high-performance computing platforms heavily depend on the inherent level of parallelism of the algorithms to be executed onto them. However, the majority of the state-of-the-art unmixing algorithms were not originally conceived for being parallelized in an ulterior stage, which clearly restricts the amount of acceleration that can be reached. As far as advanced hyperspectral sensors have increasingly high spatial, spectral, and temporal resolutions, it is hence mandatory to follow a new approach that consists of developing a new class of highly parallel unmixing solutions that can take full advantage of the characteristics of nowadays high-performance computing architectures. This paper represents a step forward toward this direction as it proposes a new parallel algorithm for fully unmixing a hyperspectral image together with its implementation onto two different NVIDIA graphic processing units (GPUs). The results obtained reveal that our proposal is able to unmix hyperspectral images with very different spatial patterns and size better and much faster than the best GPU-based unmixing chains up-to-date published, with independence of the characteristics of the selected GPU.
Auteurs: Ernestina Martel;Raúl Guerra;Sebastián López;Roberto Sarmiento;
Apparue dans: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Date publication: 03.-2017, volume: 10, issue:3, pages: 818 - 834
Editeur: IEEE
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» A Grey Wolf-Assisted Perturb & Observe MPPT Algorithm for a PV System
Résumé:
This paper proposes a new hybrid maximum power point tracking (MPPT) algorithm combining grey wolf optimization (GWO) and perturb & observe (P&O) technique for efficient extraction of maximum power from a photovoltaic system subjected to rapid variation of solar irradiance and partial shading conditions. GWO handles the initial stages of MPPT followed by application of the P&O algorithm at the final stage in view of achieving faster convergence to the global peak (GP). This MPPT thus overcomes the computational overhead as encountered in the case of a GWO-based MPPT algorithm reported earlier by Mohanty et al. The idea behind using the hybrid technique is to scale down the search space of GWO which helps to speed up for achieving convergence toward the GP. The proposed MPPT algorithm is first implemented using MATLAB/Simulink and subsequently an experimental setup is prepared for its practical implementation. From the obtained results, it is confirmed that the proposed MPPT provides superior tracking performance in any weather conditions compared to both GWO and PSO+PO-based MPPT algorithms.
Auteurs: Satyajit Mohanty;Bidyadhar Subudhi;Pravat Kumar Ray;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 340 - 347
Editeur: IEEE
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» A Hand-Held Assistant for Semiautomated Percutaneous Needle Steering
Résumé:
Objective: Permanent prostate brachytherapy is an effective and popular treatment modality for prostate cancer in which long needles are inserted into the prostate. Challenges associated with manual needle insertion such as needle deflection limit this procedure to primarily treat the entire prostate gland even for patients with localized cancer. In this paper, we present a new semiautomated hand-held needle steering assistant designed to help surgeons improve needle placement accuracy. Methods: Regular clinical brachytherapy needles are connected to a compact device that the surgeon holds. As the surgeon inserts the needle, the device rotates the needle base on a measured and calculated basis in order to produce a desired trajectory of the needle tip. A novel needle–tissue interaction model and a steering algorithm calculate such control actions based on ultrasound images of the needle in tissue. The assistant can also apply controlled longitudinal microvibrations to the needle that reduce needle–tissue friction. Results: Experimental validation of the proposed system in phantom and ex-vivo biological tissue report an average needle targeting accuracy of 0.33 mm over 72 needle insertions in 12 different experimental scenarios. Conclusion: We introduce a new framework for needle steering in prostate brachytherapy in which the surgeon remains in charge of the needle insertion. The device weighs 160 g, making it easy to incorporate with current insertion techniques. Significance: Expected benefits of the proposed system include more precise needle targeting accuracy, which can result in improved focal treatment of prostate cancer.
Auteurs: Carlos Rossa;Nawaid Usmani;Ronald Sloboda;Mahdi Tavakoli;
Apparue dans: IEEE Transactions on Biomedical Engineering
Date publication: 03.-2017, volume: 64, issue:3, pages: 637 - 648
Editeur: IEEE
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» A Hidden Markov Model for 3D Catheter Tip Tracking With 2D X-ray Catheterization Sequence and 3D Rotational Angiography
Résumé:
In minimal invasive image guided catheterization procedures, physicians require information of the catheter position with respect to the patient’s vasculature. However, in fluoroscopic images, visualization of the vasculature requires toxic contrast agent. Static vasculature roadmapping, which can reduce the usage of iodine contrast, is hampered by the breathing motion in abdominal catheterization. In this paper, we propose a method to track the catheter tip inside the patient’s 3D vessel tree using intra-operative single-plane 2D X-ray image sequences and a peri-operative 3D rotational angiography (3DRA). The method is based on a hidden Markov model (HMM) where states of the model are the possible positions of the catheter tip inside the 3D vessel tree. The transitions from state to state model the probabilities for the catheter tip to move from one position to another. The HMM is updated following the observation scores, based on the registration between the 2D catheter centerline extracted from the 2D X-ray image, and the 2D projection of 3D vessel tree centerline extracted from the 3DRA. The method is extensively evaluated on simulated and clinical datasets acquired during liver abdominal catheterization. The evaluations show a median 3D tip tracking error of 2.3 mm with optimal settings in simulated data. The registered vessels close to the tip have a median distance error of 4.7 mm with angiographic data and optimal settings. Such accuracy is sufficient to help the physicians with an up-to-date roadmapping. The method tracks in real-time the catheter tip and enables roadmapping during catheterization procedures.
Auteurs: Pierre Ambrosini;Ihor Smal;Daniel Ruijters;Wiro J. Niessen;Adriaan Moelker;Theo Van Walsum;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 03.-2017, volume: 36, issue:3, pages: 757 - 768
Editeur: IEEE
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» A High Dynamic-Range Neural Recording Chopper Amplifier for Simultaneous Neural Recording and Stimulation
Résumé:
Closed-loop neuromodulation is essential for the advance of neuroscience and for administering therapy in patients suffering from drug-resistant neurological conditions. Neural stimulation generates large artifacts at the recording sites, which easily saturate traditional recording front ends. This paper presents a neural recording chopper amplifier capable of handling in-band artifacts up to 40 mVpp while preserving the accompanying small neural signals. New techniques have been proposed that solve the issues of low input impedance and electrode-offset rejection, which enable a DC input impedance of 300 $text{M}Omega $ and a dynamic range of 69 dB (200 Hz–5 kHz) and 78 dB (1–200 Hz). Implemented in a 40-nm CMOS process, the prototype occupies an area of 0.071 mm2/channel, and consumes $2~mu text{W}$ from a 1.2 V supply. The input-referred noise is $7~mu text{V}_{mathrm {rms}}$ (200 Hz–20 kHz) and $2~mu text{V}_{mathrm {rms}}$ (1–200 Hz). The total harmonic distortion for a 20-mVp input at 1 kHz is −74 dB. This paper improves the linearity by 14–26 dB, dynamic range by 11–28 dB, and input-impedance for chopped front ends by a factor of 11 as compared with the current state of the art, while achieving similar power and noise performance.
Auteurs: Hariprasad Chandrakumar;Dejan Marković;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 645 - 656
Editeur: IEEE
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» A High-Accuracy Wind Power Forecasting Model
Résumé:
In this letter, a forecasting model consisting of the Gaussian process with a novel composite covariance function for high-accuracy wind power forecasting is presented. The proposed composite covariance function is based on the exploration of joint effects between numerical weather prediction features. The performance of the proposed forecasting model is evaluated using the 2012 global energy forecasting competition wind power forecasting data, and the proposed model outperforms all of the competitors.
Auteurs: Shengchen Fang;Hsiao-Dong Chiang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1589 - 1590
Editeur: IEEE
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» A High-Speed and Power-Efficient Voltage Level Shifter for Dual-Supply Applications
Résumé:
This brief presents a fast and power-efficient voltage level-shifting circuit capable of converting extremely low levels of input voltages into high output voltage levels. The efficiency of the proposed circuit is due to the fact that not only the strength of the pull-up device is significantly reduced when the pull-down device is pulling down the output node, but the strength of the pull-down device is also increased using a low-power auxiliary circuit. Postlayout simulation results of the proposed circuit in a 0.18- \mu text{m} technology demonstrate a total energy per transition of 157 fJ, a static power dissipation of 0.3 nW, and a propagation delay of 30 ns for input frequency of 1 MHz, low supply voltage level of V_{math\rm {{DDL}}}= 0.4 V, and high supply voltage level of V_{math\rm {{DDH}}}= 1.8 V.
Auteurs: Seyed Rasool Hosseini;Mehdi Saberi;Reza Lotfi;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 1154 - 1158
Editeur: IEEE
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» A History of Baseball and Paper Mills [History]
Résumé:
On Saturday night, 22 October 2016, I witnessed the Chicago Cubs clinch a place in baseball's 2016 World Series after capturing the pennant during the National League Central Division playoffs with the Los Angeles Dodgers. Not since 1945 had this baseball club been able to accomplish this extraordinary feat. It was on 28 May 1957, at a National League baseball owners midseason meeting in Chicago, that the decision was made to move the Brooklyn Dodgers franchise to Los Angeles. Chicago, of course, has always been known as a baseball town, and the young Cubs players, in their early 20s, magically captured the hearts of their devoted fans in winning their place in history once again.
Auteurs: Barry C. Brusso;
Apparue dans: IEEE Industry Applications Magazine
Date publication: 03.-2017, volume: 23, issue:2, pages: 7 - 11
Editeur: IEEE
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» A Hybrid Magnetoelastic Wireless Sensor for Detection of Food Adulteration
Résumé:
This paper investigates a step by step design procedure of a hybrid passive wireless sensor. The hybrid sensor measures both the electrical (dielectric constant) and the mechanical (viscosity) properties of liquid, providing a two-factor quality control. The hybrid sensor is based on an inductor-capacitor resonant tank coupled with a magnetoelastic strip. The mechanical and the electrical resonances change as a function of viscosity and dielectric constant, respectively. Two different hybrid sensor designs are investigated: 1) a parallel plate capacitor coupled with a separate amorphous ferromagnetic magnetoelastic strip (Metglas) and 2) a capacitor made using two parallel mounted magnetoelastic strips. The sensors are integrated as part of the “smart vial” making it field operable for food quality monitoring and control. Here, detection of adulteration in extra virgin olive oil is achieved by measuring the change in viscosity and dielectric constant for different adulteration levels. The real part of the dielectric constant for different liquid samples is measured in the frequency range of 3–24 MHz. The hybrid sensor is able to detect adulteration levels below 10% in volume. These sensors can be integrated with passive RFIDs for simultaneous measurement of multiple samples in an array format.
Auteurs: Saranraj Karuppuswami;Amanpreet Kaur;Harikrishnan Arangali;Premjeet Prem Chahal;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1706 - 1714
Editeur: IEEE
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» A Hybrid Recommendation Model for Learning Object Repositories
Résumé:
Learning Objects (LOs) have emerged as a cornerstone approach for the development and distribution of educational content. These resources are distributed by Learning Object Repositories (LORs), which can make it easier for users to find suitable LOs by using Recommender Systems (Rss). This paper presents a hybrid recommendation model for LORs that combines content-based, demographic and context-aware techniques, along with the use of quality and popularity metrics. This article also describes how the model has been used to implement two RSs for two real LORs: ViSH and Europeana. Each of these RSs was evaluated in terms of accuracy, utility,usability and satisfaction perceived by end users. Besides, an A/B testing was performed in ViSH to compare the recommendations of the RS with random suggestions. The results showed that the RSs had a high user acceptance in terms of utility, usability and satisfaction, and that the RSs significantly exceeded the performance achieved by the random recommendations.
Auteurs: Aldo Gordillo;Enrique Barra;Juan Quemada;
Apparue dans: IEEE Latin America Transactions
Date publication: 03.-2017, volume: 15, issue:3, pages: 462 - 473
Editeur: IEEE
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» A Hybrid Temporal Reasoning Framework for Fall Monitoring
Résumé:
This paper presents a real-time method for detecting a fall at different phases using a wireless tri-axial accelerometer and reports the classification performance when the sensor is placed on different body parts. The proposed hybrid framework combines a rule-based knowledge representation scheme with a time control mechanism and machine-learning-based activity classification. Real-time temporal reasoning is performed using a standard rule-based inference engine. The framework is validated for fall detection performance, false alarm evaluation, and comparison with a highly cited baseline method. Based on a data set with 14 fall types (280 falls) collected from 16 subjects, the highest accuracy values of 86.54%, 87.31%, and 91.15% are obtained for fall detection at pre-impacts, impacts, and post-impacts, respectively. Without post-impact activity information, the side of the waist and chest are the best sensor positions, followed by the head, front of the waist, wrist, ankle, thigh, and upper arm. With post-impact activity information, the best sensor position is the side of the waist, followed by the head, wrist, front of the waist, thigh, chest, ankle, and upper arm. Most false alarms occur during transitions of lying postures. The proposed method is more robust to a variety of fall and activity types and yields better classification performance and false alarm rates compared with the baseline method. The results provide guidelines for sensor placement when developing a fall monitoring system.
Auteurs: Natthapon Pannurat;Surapa Thiemjarus;Ekawit Nantajeewarawat;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1749 - 1759
Editeur: IEEE
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» A Linear Equivalent Circuit Model for Depletion-Type Silicon Microring Modulators
Résumé:
We present a linear equivalent circuit model for the depletion-type Si microring modulator (MRM). Our model consists of three blocks: one for parasitic components due to interconnects and pads, one for the electrical elements of the core p-n junction, and the third for a lossy LC tank representing Si MRM optical modulation characteristics. Model parameter values are extracted from measurement of a fabricated Si MRM device. Simulated modulation characteristics with our equivalent circuit show very good agreement with measured results. Using our model, we can analyze Si MRM modulation frequency response characteristics and perform gain-bandwidth product optimization of the entire Si photonic transmitter composed of a Si MRM and electrical driver circuits.
Auteurs: Myungjin Shin;Yoojin Ban;Byung-Min Yu;Min-Hyeong Kim;Jinsoo Rhim;Lars Zimmermann;Woo-Young Choi;
Apparue dans: IEEE Transactions on Electron Devices
Date publication: 03.-2017, volume: 64, issue:3, pages: 1140 - 1145
Editeur: IEEE
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» A Linearizing Digitizer for Wheatstone Bridge Based Signal Conditioning of Resistive Sensors
Résumé:
Output of a typical Wheatstone bridge, when it is connected to measure from a single or a dual resistive element, possesses non-linear characteristic. This paper presents a novel signal conditioning scheme, which provides a linear-digital output directly from the resistive sensor(s) that are connected in such bridge configurations. In the present scheme, the input stage of a dual-slope analog-to-digital converter (DSADC) is suitably augmented to incorporate the quarter-bridge and (or) half-bridge containing the resistive sensor as an integral part of the DSADC. A combination of the current mode excitation and wisely selected integration and de-integration operations of the DSADC enable to achieve linearization in the digitization process itself, leading to an overall reduction in the complexity level and number of blocks used keeping the high accuracy unaltered. A detailed analysis has been conducted to quantify the effect of various sources of errors in the output of the DSADC. The details are presented in the paper. The proposed method not only provides a linear digital output but also drastically reduces the effect on the output due to the lead wires that connect the Wheatstone bridge and the DSADC. Thus, the proposed scheme is well suited for the situations where the sensor(s) is (are) remotely located at a distance. Simulation studies as well as results from a prototype developed and tested establish the practicality of the proposed scheme. The inherent non-linearity of the Wheatstone bridge is reduced by nearly two orders of magnitude.
Auteurs: Ponnalagu Ramanathan Nagarajan;Boby George;Varadarajan Jagadeesh Kumar;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1696 - 1705
Editeur: IEEE
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» A Location-Based Mobile Crowdsensing Framework Supporting a Massive Ad Hoc Social Network Environment
Résumé:
This article addresses one of the key challenges of engaging a massive ad hoc crowd by providing sustainable incentives. The incentive model is based on a context-aware cyber-physical spatio-temporal serious game with the help of a mobile crowd sensing mechanism. To this end, this article describes a framework that can create an ad hoc social network of millions of people and provide context-aware serious-game services as an incentive. While interacting with different services, the massive crowd shares a rich trail of geo-tagged multimedia data, which acts as a crowdsourcing eco-system. The incentive model has been tested on the mass crowd at the Hajj since 2014. From our observations, we conclude that the framework provides a sustainable incentive mechanism that can solve many real-life problems such as reaching a person in a crowd within the shortest possible time, isolating significant events, finding lost individuals, handling emergency situations, helping pilgrims to perform ritual events based on location and time, and sharing geo-tagged multimedia resources among a community of interest within the crowd. The framework allows an ad hoc social network to be formed within a very large crowd, a community of interests to be created for each person, and information to be shared with the right community of interests. We present the communication paradigm of the framework, the serious game incentive model, and cloud-based massive geo-tagged social network architecture.
Auteurs: Md. Abdur Rahman;M. Shamim Hossain;
Apparue dans: IEEE Communications Magazine
Date publication: 03.-2017, volume: 55, issue:3, pages: 76 - 85
Editeur: IEEE
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» A Long Duration Transient Resilient Pipeline Scheme
Résumé:
Single event transients (SETs) in combinational logic remain an important topic in the reliability domain. SETs were traditionally relatively short in comparison to the clock period. The majority of the countermeasures utilizes this property. However, advances in technology scaling will reverse the ratio for complementary metal-oxide semiconductor devices. Investigations show that SETs may last up to multiple clock cycles in the future. So-called long duration transients (LDTs) corrupt almost all available countermeasures. This paper presents a new methodology to tackle LDTs. Dual modular redundancy (DMR) is used to detect any corruption of the application logic. A new micro-rollback scheme expands the DMR architecture with fault correction capabilities. The concept is also capable of handling single event upsets and timing violations. The correction penalty is two clock cycles. The approach was implemented and verified in a Viterbi decoder architecture. The scheme utilizes a newly designed History Cell. The History Cell introduces an area overhead of 97% and a power overhead of 110%, compared to a standard cell DFF.
Auteurs: Erol Koser;Walter Stechele;
Apparue dans: IEEE Transactions on Device and Materials Reliability
Date publication: 03.-2017, volume: 17, issue:1, pages: 12 - 19
Editeur: IEEE
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» A Low Voltage SRAM Using Resonant Supply Boosting
Résumé:
This paper presents a novel resonating inductor-based supply boosting scheme for low-voltage static random-access memories and logic in deep 14-nm silicon on insulator (SOI) FinFET technologies. The technique combines capacitive (C) and inductive (L) boosting for the first time. Simulation and measured hardware results from a 14-nm test chip show that this new technique is able to improve $V_{mathrm {min}}$ (down to 0.3 V), functional yield, and access time, when compared with designs with or without capacitive-boosted supplies. Simulations also reveal the optimal combinations of “L” and “C” needed for each $V_{mathrm {dd}}$ to achieve minimal boost voltage, where the static random-access memory can be rendered fully functional in the absence of any assist circuitry. Furthermore, the resonant supply provides power savings compared with a boosted supply alone.
Auteurs: Rajiv V. Joshi;Matthew M. Ziegler;Holger Wetter;
Apparue dans: IEEE Journal of Solid-State Circuits
Date publication: 03.-2017, volume: 52, issue:3, pages: 634 - 644
Editeur: IEEE
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» A Low-Power Wireless Piezoelectric Sensor-Based Respiration Monitoring System Realized in CMOS Process
Résumé:
This paper presents a methodology of monitoring respiration pattern using piezoelectric transducer incorporating CMOS integrated circuits for signal processing and data transmission. As a proof of concept, the system has been tested by placing electrodes on human chest using adhesive hydrogel to detect the pulsatile vibration due to respiration. The system can be used either as a wearable device itself or alternatively can be attached to a jacket or a chest belt. The front-end transducer is a piezoelectric material-based sensor, which is comprised of a ferroelectric polymer named polyvinylidene-fluoride (PVDF). PVDF is also biocompatible, which makes the sensor suitable to be used as a wearable device. The charge produced by the sensor is converted to a proportional voltage signal with the help of a charge amplifier designed in a standard 130-nm CMOS process with eight metal and one poly layer. The analog voltage signal acquired from the charge amplifier is then converted into a digital signal using a reconfigurable pipelined analog-to-digital converter for ease of transmission. An impulse-radio ultra-wideband transmitter operating in the frequency range of 3.1–5 GHz is designed for wireless transmission of the data. The smaller footprint, lighter weight, wireless telemetry, and low-cost material along with the low-power integrated CMOS circuitry for signal processing and data transmission make the proposed system an attractive choice for stable respiration monitoring system.
Auteurs: Ifana Mahbub;Salvatore Andrea Pullano;Hanfeng Wang;Syed Kamrul Islam;Antonino S. Fiorillo;Gary To;M. R. Mahfouz;
Apparue dans: IEEE Sensors Journal
Date publication: 03.-2017, volume: 17, issue:6, pages: 1858 - 1864
Editeur: IEEE
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» A Low-Profile Aperture-Coupled Microstrip Antenna With Enhanced Bandwidth Under Dual Resonance
Résumé:
A low-profile aperture-coupled microstrip patch antenna (MPA) using the TM10 and TM30 resonant modes to enhance the impedance bandwidth is proposed in this paper. Based on the cavity model for a square MPA, the TM10 and TM30 modes as well as both higher odd-order and even-order modes between them can be characterized. In order to combine the dual radiative resonant modes for a wide impedance bandwidth, a rectangular radiating patch with an aperture-coupled feeder is employed and theoretically investigated at first, aiming to demonstrate that all of the undesired modes between them can be removed effectively. After that, by loading the shorting pins properly underneath the patch, the resonant frequency of TM10 mode is shown to progressively turn up with slight effect on that of TM30 mode. As a result, these two radiative modes can be allocated in proximity to each other, resulting in a wide impedance bandwidth with a stable radiation pattern and the same far-field polarization. Moreover, the principal parameters of the MPA have been extensively studied in order to investigate the sensitivity in input impedance of the aperture-fed patch antenna. Finally, the proposed antenna is fabricated and measured. Simulated and measured results are found in good agreement with each other and illustrate that the antenna achieves a wide impedance bandwidth of about 15.2% in fraction or 2.32–2.70 GHz under $vert text{S}_{mathrm {mathbf {11}}}vert < -10$ dB, while keeping a low profile property with the height of 0.032 free-space wavelength. Besides, a stable gain varied from 3 to 6.8 dBi within the whole operating band is also obtained.
Auteurs: Neng-Wu Liu;Lei Zhu;Wai-Wa Choi;Xiao Zhang;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1055 - 1062
Editeur: IEEE
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» A Mathematical Model for Determining an Electrohydrodynamic Accelerator’s Monopolar Flow Limit During Positive Corona Discharge
Résumé:
This paper presents a mathematical model establishing the velocity limit of electrohydrodynamics fluid accelerators with tip to plane and cylinder to plane electrode configurations. The model is based on the calculation of the electric field lines length and trajectory, allowing practical use even if only the spatial characteristics of the geometry, the fluid’s ion mobility and the applied voltage are known. Experiments are performed with wire-plane and needle-grid electrode configurations to validate the developed mathematical model, both for the calculation of the average flow limit of the geometry and for the calculation of the flow limit at the end of each electric field line.
Auteurs: Emmanouil D. Fylladitakis;Antonios X. Moronis;Michael P. Theodoridis;
Apparue dans: IEEE Transactions on Plasma Science
Date publication: 03.-2017, volume: 45, issue:3, pages: 432 - 440
Editeur: IEEE
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» A Meeting of Materials: Integrating Diverse Semiconductor Technologies for Improved Performance at Lower Cost
Résumé:
Semiconductor technology has seen rapid advances in recent years. Complementary?metal-oxide-semiconductor (CMOS) technology is providing tremendous digital processing power by integrating billions of transistors. Indium phosphide (InP) has bridged the terahertz frequency barrier. Gallium nitride (GaN) is offering unprecedented solid-state RF power across the microwave spectrum. Diverse, accessible heterogeneous integration (DAHI) allows engineers to take advantage of all of these advances by combining them along with other semiconductor technologies onto a single chip. DAHI offers the ultimate in RF, mixedsignal, and digital capability for future mobile applications that will demand smaller size and weight with lower power and cost.
Auteurs: Augusto Gutierrez-Aitken;Bryan Yi-Cheng Wu;Dennis Scott;Ken Sato;Benjamin Poust;Monte Watanabe;Cedric Monier;Nancy Lin;Xiang Zeng;Eric Nakamura;Peter Cheng;Eric Kaneshiro;Wesley Chan;Ioulia Smorchkova;Khanh Thai;Sujane Wang;David Slavin;Aaron Oki;Rey
Apparue dans: IEEE Microwave Magazine
Date publication: 03.-2017, volume: 18, issue:2, pages: 60 - 73
Editeur: IEEE
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» A Method and Toolkit for Digital Musical Instruments: Generating Ideas and Prototypes
Résumé:
Digital musical instruments (DMIs) make up a class of devices in which gestural control and sound production are physically decoupled, but digitally mapped. This work discusses aspects of DMI design by focusing on the complexity of the design space and the importance of prototyping cycles. The authors' research questions cover how to provide an initial path for generating DMI ideas and how to reduce the time and effort required to build functional DMI prototypes. To address these questions, they propose a new methodology and an associated physical prototyping toolkit, which has building blocks inspired by of existing instruments. Preliminary tests with musicians and DMI designers revealed a strong potential for its use in the development of DMIs, and also uncovered limitations of the current toolkit. This article is part of a special issue on multimedia technologies for enriched music.
Auteurs: Filipe Calegario;Marcelo M. Wanderley;Stéphane Huot;Giordano Cabral;Geber Ramalho;
Apparue dans: IEEE Multimedia
Date publication: 03.-2017, volume: 24, issue:1, pages: 63 - 71
Editeur: IEEE
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» A Method to Start Rotating Induction Motor Based on Speed Sensorless Model-Predictive Control
Résumé:
In some cases, such as restarting after power interruption or starting a motor rotated by external load, the motor may be rotating before being powered by the inverter. For speed-sensorless operation, as both the initial rotational direction and speed is unknown, it would be difficult to achieve smooth and fast resumption of normal operation if the starting scheme is not deliberately designed. In this paper, a method based on adaptive full order observer (AFO) is proposed to address this problem. For AFO without a properly designed feedback gain matrix, the estimated speed cannot converge to the actual speed if initial estimated speed is significantly lower than the actual speed. Through analyzing the transfer function of stator current error, the convergence condition of speed estimation is deduced. A feedback gain matrix and the condition for shifting to normal operation are subsequently proposed to improve restarting performance. The detailed design and implementation of the proposed method combined with finite control set model-predictive flux control is illustrated. Simulation and experimental results validate the effectiveness of the developed schemes.
Auteurs: Haitao Yang;Yongchang Zhang;Paul D. Walker;Nong Zhang;Bo Xia;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 359 - 368
Editeur: IEEE
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» A Methodology for Short-Term Load Forecasting
Résumé:
Demand forecasting is important for electrical analysis development by utilities. It requires low error levels in order to reach reliability in electrical analysis. However, the demand for energy has dissimilar profiles variations depending on the type of day, weather conditions and geographical area. For this reason, it is necessary to group those curves showing similar behaviors and characterize them to establish which factors are significant for understanding. This paper proposes a novel methodology to identify those significant factors in the forecasting model for energy demand, and measure their effect on the Mean Absolute Percentage Error (MAPE) criterion and error performance. The experimental results show advantages of this methodology for zones with several behaviors in hourly power consumption.
Auteurs: Jamer Jimenez Mares;Katheryn Donado Mercado;Christian G. Quintero M.;
Apparue dans: IEEE Latin America Transactions
Date publication: 03.-2017, volume: 15, issue:3, pages: 400 - 407
Editeur: IEEE
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» A Minorization–Maximization Algorithm for Maximizing the Secrecy Rate of the MIMOME Wiretap Channel
Résumé:
We consider physical layer security in a multi-input multi-output multi-eavesdropper wiretap channel and present an exact solution to the problem of secrecy rate maximization. A system model with multiple multi-antenna eavesdroppers and multiple multi-antenna full-duplex receivers is considered, which is general enough such that models existing in the literature may be considered as special cases. In particular, we perform joint beamforming and artificial noise optimization in an effort to maximize the achievable secrecy rate. The optimization is performed in the presence of artificial noise generated by both transmitter and legitimate receivers. The resulting optimization problem is non-convex and difficult to solve. We develop a minorization–maximization algorithm to solve the problem exactly and the results can therefore be used to benchmark existing methods. Numerical results are presented to demonstrate the efficacy of the proposed approach.
Auteurs: Mudassir Masood;Ali Ghrayeb;Prabhu Babu;Issa Khalil;Mazen Hasna;
Apparue dans: IEEE Communications Letters
Date publication: 03.-2017, volume: 21, issue:3, pages: 520 - 523
Editeur: IEEE
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» A Mixed Interval Power Flow Analysis Under Rectangular and Polar Coordinate System
Résumé:
A Rectangular Interval Power Flow (RIPF) method is proposed to improve solutions for intervals of power flow problems due to nondeterministic characteristics of demand loads and output of generators. It is based on affine arithmetic which is a self-validated numerical analysis and serves to improve the interval results through optimization method. Since no approximation is presumed, the RIPF method acquires narrower intervals of voltage phase and active power of branches than Polar Interval Power Flow (PIPF), it is an excellent method raised before. However, as RIPF is no better than that of PIPF for estimating intervals of voltage magnitude, because it relaxes restriction of the voltage equations. Therefore, a Mixed Interval Power Flow (MIPF) method is envisaged and developed in the paper to incorporate merits of RIPF for computing the intervals of voltage phase and active power of branches but not giving the advantage of PIPF for evaluating intervals of voltage magnitude. As a validation of our suggested approach, two case studies are carried out, and results conclude that the MIPF method acquires more accurate power flow intervals than the conventional method.
Auteurs: Cong Zhang;Haoyong Chen;Honwing Ngan;Ping Yang;Dong Hua;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1422 - 1429
Editeur: IEEE
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» A Model Predictive Control Approach for Low-Complexity Electric Vehicle Charging Scheduling: Optimality and Scalability
Résumé:
With the increasing adoption of plug-in electric vehicles (PEVs), it is critical to develop efficient charging coordination mechanisms that minimize the cost and impact of PEV integration to the power grid. In this paper, we consider the optimal PEV charging scheduling, where the noncausal information about future PEV arrivals is not known in advance, but its statistical information can be estimated. This leads to an “online” charging scheduling problem that is naturally formulated as a finite-horizon dynamic programming with continuous state space and action space. To avoid the prohibitively high complexity of solving such a dynamic programming problem, we provide a model predictive control (MPC)-based algorithm with computational complexity O(T^3) , where T is the total number of time stages. We rigorously analyze the performance gap between the near-optimal solution of the MPC-based approach and the optimal solution for any distributions of exogenous random variables. Furthermore, our rigorous analysis shows that when the random process describing the arrival of charging demands is first-order periodic, the complexity of the proposed algorithm can be reduced to O(1) , which is independent of T . Extensive simulations show that the proposed online algorithm performs very closely to the optimal online algorithm. The performance gap is smaller than 0.4% in most cases.
Auteurs: Wanrong Tang;Ying Jun (Angela) Zhang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1050 - 1063
Editeur: IEEE
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» A Model to Represent Correlated Time Series in Reliability Evaluation by Non-Sequential Monte Carlo Simulation
Résumé:
This paper proposes a model that represents statistically dependent time-varying quantities, such as loads, wind power generation, and water inflows, and can be applied to evaluate power systems composite reliability by Non-Sequential Monte Carlo Simulation (MCS). This proposal is based on nonparametric stochastic models, which do not require a priori characterizations of the probability density functions of the random variables. Additionally, the maximal information coefficient, which allows mapping nonlinear relationships between the variables, and Bayesian network structures, which allow handling high dimensionality problems when multiple time series are represented, are applied. The proposed model allows reliability indices to be obtained with the same accuracy as the Sequential MCS but with computational costs on the order of the Non-Sequential MCS. The model is flexible enough to represent the relationships between variables with different levels of discretization, as in the case of the wind power generation and water inflows of a hydroelectric system.
Auteurs: Carmen Lucia Tancredo Borges;Julio A. S. Dias;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1511 - 1519
Editeur: IEEE
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» A modified analysis of electrical energy consumption in University buildings
Résumé:
To analyze the concept of charge for electricity consumption, it is important to consider the type of billing-rate. Therefore, in this study a change of model analysis for the implementation of the use and consumption of electricity in university buildings is proposed. The approach that is made, is based on recent changes in the cost of energy in relation to the tariff that most university buildings have. Based on the physical conditions, equipment and number of users, in combination with rate type of the university buildings, indicators of consumption and use of electric power are proposed. In the same way, an analysis of the variability of the cost and use of electrical energy that allows identify a change in the actions that traditionally were being made to reduce the costs of billing is made.
Auteurs: Jesus Martinez Patino;Fernando Ireta Moreno;Miguel Angel Hernandez Figueroa;Jose Merced Lozano Garcia;Heriberto Gutierrez Martin;
Apparue dans: IEEE Latin America Transactions
Date publication: 03.-2017, volume: 15, issue:3, pages: 408 - 414
Editeur: IEEE
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» A Modified Tolles–Lawson Model Robust to the Errors of the Three-Axis Strapdown Magnetometer
Résumé:
The estimating of the Tolles–Lawson model’s coefficients plays an important role in aeromagnetic compensation. The directional cosines, which are indispensable for estimating the coefficients, are usually measured by a three-axis strapdown magnetometer in a general aeromagnetic survey system. However, in some cases, the scalar magnetometer may have a much higher accuracy than the three-axis strapdown magnetometer. This imbalance of the measurement accuracy is then introduced into the Tolles–Lawson model and affects the estimation of the coefficients. In this letter, a modified Tolles–Lawson model is introduced to reduce the imbalance through substituting the error model of the three-axis strapdown magnetometer into the calculation of the directional cosines. The characteristics of the modified model are analyzed and the corresponding coefficient-estimating system is developed. Simulation results illustrate that the modified model is more robust to the larger errors of the three-axis strapdown magnetometer than the classical model.
Auteurs: Qi Han;Zhenjia Dou;Xiaojun Tong;Xiang Peng;Hong Guo;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 03.-2017, volume: 14, issue:3, pages: 334 - 338
Editeur: IEEE
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» A Multi-Grid Iterative Method for Photoacoustic Tomography
Résumé:
Inspired by the recent advances on minimizing nonsmooth or bound-constrained convex functions on models using varying degrees of fidelity, we propose a line search multi-grid (MG) method for full-wave iterative image reconstruction in photoacoustic tomography (PAT) in heterogeneous media. To compute the search direction at each iteration, we decide between the gradient at the target level, or alternatively an approximate error correction at a coarser level, relying on some predefined criteria. To incorporate absorption and dispersion, we derive the analytical adjoint directly from the first-order acoustic wave system. The effectiveness of the proposed method is tested on a total-variation penalized Iterative Shrinkage Thresholding algorithm (ISTA) and its accelerated variant (FISTA), which have been used in many studies of image reconstruction in PAT. The results show the great potential of the proposed method in improving speed of iterative image reconstruction.
Auteurs: Ashkan Javaherian;Sean Holman;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 03.-2017, volume: 36, issue:3, pages: 696 - 706
Editeur: IEEE
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» A Multi-Objective Model Oriented Mapping Approach for NoC-based Computing Systems
Résumé:
In this paper, a multi-objective, i.e., reliability, communication energy, performance, co-optimization model oriented mapping approach is proposed to find optimal mappings when applications are mapped onto network-on-chip (NoC) based reconfigurable architectures. A co-optimization model, defined as reliability efficiency model (REM), is developed to evaluate the overall reliability efficiency of a mapping. In REM, reliability efficiency is defined as the reliability profit at the same energy latency product. Based on REM, a mapping approach, referred to as priority and compensation factor oriented branch and bound (PCBB), is introduced to figure out the best mapping pattern. Two techniques, priority allocation and compensation factor utilization, are adopted to make a tradeoff between search efficiency and accuracy. Experimental results show that the proposed approach has three major contributions compared to state-of-the-art approaches. (1) PCBB is highly efficient in finding best mappings, with a 3x and 720x speedup compared to branch and bound (BB) and simulated annealing (SA). (2) PCBB is able to dynamically remap after the reconfiguration of the architecture. (3) General quantitative evaluation for reliability, communication energy and performance are made respectively before integrated into the unified model REM, whereas other similar models only touch upon two of them quantitatively.
Auteurs: Chen Wu;Chenchen Deng;Leibo Liu;Jie Han;Jiqiang Chen;Shouyi Yin;Shaojun Wei;
Apparue dans: IEEE Transactions on Parallel and Distributed Systems
Date publication: 03.-2017, volume: 28, issue:3, pages: 662 - 676
Editeur: IEEE
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» A Multi-Solver Scheme Based on Combined Field Integral Equations for Electromagnetic Modeling of Highly Complex Objects
Résumé:
A combined field integral equation (CFIE)-based multisolver scheme is presented for electromagnetic modeling of objects with complex structures and materials. In this scheme, an object is decomposed into multiple bodies based on its material property and geometry. To model bodies with complicated materials, the finite element-boundary integral (FE-BI) method is applied. To model bodies with homogeneous or conducting materials, the method of moments is employed. Specifically, three solvers are integrated in this multi-solver scheme: the FE-BI(CFIE) for inhomogeneous objects, the CFIE for dielectric objects, and the CFIE for conducting objects. A mixed testing scheme that utilizes both the Rao–Wilton–Glisson and the Buffa–Christiansen functions is adopted to obtain a good accuracy. In the iterative solution of the combined system, the multilevel fast multipole algorithm is applied to accelerate computation and reduce memory costs, and a preconditioner based on an absorbing boundary condition is employed to speed up the convergence. In the numerical examples, the individual solvers are first demonstrated to be well conditioned and highly accurate. Then, the validity of the proposed multisolver scheme is demonstrated and its capability is shown by solving scattering problems of electrically large missilelike objects.
Auteurs: Jian Guan;Su Yan;Jian-Ming Jin;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1236 - 1247
Editeur: IEEE
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» A Multi-Tenant Cloud-Based DC Nano Grid for Self-Sustained Smart Buildings in Smart Cities
Résumé:
Energy is one of the most valuable resources of the modern era and needs to be consumed in an optimized manner by an intelligent usage of various smart devices, which are major sources of energy consumption nowadays. With the popularity of low-voltage DC appliances such as-LEDs, computers, and laptops, there arises a need to design new solutions for self-sustainable smart energy buildings containing these appliances. These smart buildings constitute the next generation smart cities. Keeping focus on these points, this article proposes a cloud-assisted DC nanogrid for self-sustainable smart buildings in next generation smart cities. As there may be a large number of such smart buildings in different smart cities in the near future, a huge amount of data with respect to demand and generation of electricity is expected to be generated from all such buildings. This data would be of heterogeneous types as it would be generated from different types of appliances in these smart buildings. To handle this situation, we have used a cloudbased infrastructure to make intelligent decisions with respect to the energy usage of various appliances. This results in an uninterrupted DC power supply to all low-voltage DC appliances with minimal dependence on the grid. Hence, the extra burden on the main grid in peak hours is reduced as buildings in smart cities would be self-sustainable with respect to their energy demands. In the proposed solution, a collection of smart buildings in a smart city is taken for experimental study controlled by different data centers managed by different utilities. These data centers are used to generate regular alerts on the excessive usage of energy from the end users' appliances. All such data centers across different smart cities are connected to the cloud-based infrastructure, which is the overall manager for making all the decisions about energy automation in smart cities. The efficacy of the proposed scheme is evaluated with respect to various pe- formance evaluation metrics such as satisfaction ratio, delay incurred, overhead generated, and demand-supply gap. With respect to these metrics, the performance of the proposed scheme is found to be good for implementation in a realworld scenario.
Auteurs: Neeraj Kumar;Athanasios V. Vasilakos;Joel J. P. C. Rodrigues;
Apparue dans: IEEE Communications Magazine
Date publication: 03.-2017, volume: 55, issue:3, pages: 14 - 21
Editeur: IEEE
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» A Multichip Phase-Leg IGBT Module Bonded by Pressureless Sintering of Nanosilver Paste
Résumé:
This paper presents the design, development, and optimization of large-area die attachment by pressureless sintering of nanosilver paste. With the proposed die attachment, a high power 1200 V/150 A insulated-gate-bipolar-transistor (IGBT) module is fabricated using large-area IGBT ( ${12.56 times 12.56}$ mm2) and diode ( ${6.3 times 6.3}$ mm2) chips. The average die-shear strength of higher than 30 MPa can be obtained with the low void ratio of 1.8%. The electrical characteristics of the IGBT module using pressureless sintered nanosilver paste have been measured and compared with the commercial one using soldered Sn5Pb92.5Ag2.5. Test result shows that this IGBT module has identical static and dynamic characteristics as the commercial one. Therefore, the pressureless sintered nanosilver could be used as an alternative to high-lead solder in power module manufacturing, especially in assembling SiC- or GaN-based devices for high temperature applications.
Auteurs: Shancan Fu;Yunhui Mei;Xin Li;Changsheng Ma;Guo-Quan Lu;
Apparue dans: IEEE Transactions on Device and Materials Reliability
Date publication: 03.-2017, volume: 17, issue:1, pages: 146 - 156
Editeur: IEEE
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» A Multiobjective Approach for Multistage Reliability Growth Planning by Considering the Timing of New Technologies Introduction
Résumé:
This paper proposes a new multiobjective multiple stage reliability growth planning (MO-MS-RGP) model. The model is based on multiobjective consideration of developing a new product, including the cost, time, and product reliability. The number of test units, test time, and the percentage of introduced new technologies are considered as decision variables in the model. Varying reliability growth rates are considered for each subsystem in each stage. Product new technologies or contents can be completely introduced in one stage or partially introduced to the product over multiple stages. New product development time limit and budget are considered as constraints in the MO-MS-RGP model. An integrated approach is developed to formulate and solve the proposed MO-MS-RGP problem. The approach starts with a multiobjective evolutionary algorithm, called multipleobjective particle swarm optimization to find a set of Pareto optimal solutions. Then, clustering methods are applied to cluster the solutions obtained by the evolutionary algorithm. Finally, the clustered solutions are ranked using a multiple criteria decision making method. A numerical example illustrates the application of the proposed MO-MS-RGP model for the reliability growth planning optimization of a next generation engine development.
Auteurs: Mohammadsadegh Mobin;Zhaojun Li;Ghorbanmohammad Komaki;
Apparue dans: IEEE Transactions on Reliability
Date publication: 03.-2017, volume: 66, issue:1, pages: 97 - 110
Editeur: IEEE
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» A Multireflect-Thru Method of Vector Network Analyzer Calibration
Résumé:
We present a new method for two-port vector network analyzer (VNA) calibration, which uses multiple offset-reflect standards and a flush thru connection. Offset-reflect standards consist of sections of the same uniform transmission line with different lengths, which are terminated with the same highly reflective load. The unknown propagation constant of the transmission line and the load reflection coefficient are then determined simultaneously with the VNA calibration coefficients. We compare our method with the multiline thru-reflect-line (TRL) method and show that both methods yield similar results. Our new multireflect-thru method is solely based upon dimensional parameters of the calibration standards. Therefore, like the multiline TRL method, it can be used to establish a traceable VNA calibration. Thus, the multireflect-thru method constitutes an alternative to the multiline TRL calibration in environments in which the use of transmission lines is troublesome, such as in the case of VNAs with very small coaxial and waveguide connectors. The multireflect-thru method is also useful in on-wafer measurements since it allows us to keep a constant distance between the probes, which reduces the impact of crosstalk and speeds up automated testing.
Auteurs: Arkadiusz Lewandowski;Wojciech Wiatr;Dazhen Gu;Nathan D. Orloff;James Booth;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 03.-2017, volume: 65, issue:3, pages: 905 - 915
Editeur: IEEE
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» A Multisensor Mobile Interface for Industrial Environment and Healthcare Monitoring
Résumé:
This paper presents a reconfigurable multisensor mobile interface architecture that is applicable to heterogeneous sensor applications and also easy to generate new types of combined services. The multisensor interface attributes compactness and flexibility to reconfigurable readout integrated circuits (ROICs) and migration of signal processing and computation burdens from a sensor tag to a smartphone. Two reconfigurable ROICs which were designed and fabricated in a 0.18-μm CMOS process generate raw digital data from environmental and healthcare sensors. Their detected raw data are wirelessly sent to the smartphone where real-time calibration and postprocessing are performed optimally for each sensor. In an application to industrial systems, an in-vehicle system prototype supporting combined monitoring services of air-quality and healthcare was integrated into a steering wheel cover and experimentally verified to provide real-time measurement of three environmental sensor signals and two healthcare physiological signals with the results displayed on a smartphone.
Auteurs: Subin Choi;Dae Jung Kim;Yun Young Choi;Kyeonghwan Park;Sung-Woo Kim;Sung Hun Woo;Jae Joon Kim;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 2344 - 2352
Editeur: IEEE
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» A Near BER-Optimal Decoding Algorithm for Convolutionally Coded Relay Channels With the Decode-and-Forward Protocol
Résumé:
Relay-assisted communication has been shown to be an effective technique to improve the reliability and throughput of real-world wireless communication networks. It enables single-antenna users to form a virtual antenna array without installing multiple antennas at the transmitter or the receiver. This paper re-examines the decoding problem in the convolutionally coded relay channel with the classical decode-and-forward protocol. By tackling the challenge of modeling the error propagation effect at the relay, a near BER-optimal decoding (NBOD) algorithm at the destination is derived, assuming the availability of perfect receiver channel state information. Its decoding complexity is linear in the information block length, while the exact BER-optimal decoding algorithm with a sub-exponential complexity is still unknown. The major approximation involved in the derivation of the NBOD algorithm is the pairwise error probability approximation that causes a practically insignificant degradation from the optimal BER performance. Our simulation result confirms that the proposed NBOD algorithm can perform close to the maximum likelihood performance bound on BER in the three-node one-way relay channel scenario. In addition, we have further extended the proposed algorithm for more general single-source single-destination decode-and-forward-based relay networks. Simulation results further verify that the proposed NBOD algorithm can outperform existing decoding algorithms based on maximal-ratio combining and selective decode-and-forward in various relay channel scenarios at the cost of higher complexity.
Auteurs: Bin Qian;Wai Ho Mow;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 03.-2017, volume: 16, issue:3, pages: 1767 - 1781
Editeur: IEEE
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» A Necessary Condition for Power Flow Insolvability in Power Distribution Systems With Distributed Generators
Résumé:
This paper proposes a necessary condition for power flow insolvability in power distribution systems with distributed generators (DGs). We show that the proposed necessary condition indicates the impending singularity of the Jacobian matrix and the onset of voltage instability. We consider different operation modes of DG inverters, e.g., constant-power and constant-current operations, in the proposed method. A new index based on the presented necessary condition is developed to indicate the distance between the current operating point and the power flow solvability boundary. Compared to existing methods, the operating condition-dependent critical loading factor provided by the proposed condition is less conservative and is closer to the actual power flow solution space boundary. The proposed method only requires the present snapshots of voltage phasors to monitor the power flow insolvability and voltage stability. Hence, it is computationally efficient and suitable to be applied to a power distribution system with volatile DG outputs. The accuracy of the proposed necessary condition and the index is validated by simulations on a distribution test system with different DG penetration levels.
Auteurs: Zhaoyu Wang;Bai Cui;Jianhui Wang;
Apparue dans: IEEE Transactions on Power Systems
Date publication: 03.-2017, volume: 32, issue:2, pages: 1440 - 1450
Editeur: IEEE
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» A New Buck Converter With Optimum-Damping and Dynamic-Slope Compensation Techniques
Résumé:
This paper presents a new buck converter with optimum-damping and dynamic-slope compensation techniques. The optimum-damping control is a well-known current control method, and the proposed dynamic-slope generator can achieve frequency compensation to prevent subharmonic oscillation. When the system is disturbed, the proposed dynamic-slope generator can stabilize the circuit in a single cycle. Hence, the dynamic-slope compensation can be used to replace traditional extra slope compensation in the optimum-damping-control circuit. The measured transient time of the load current is 2 μs from 50 to 500 mA, and 3 μs from 500 to 50 mA. The optimum-damping-control techniques can rapidly reach desired output voltage in 2–3 switching cycles. The experimental and simulation results confirm that the proposed approach can achieve the slope compensation and accelerate the transient response. The proposed converter has been fabricated with TSMC 0.18 μm CMOS 1P6M technology. The converter's operating frequency is 1 MHz, the maximum output current is 500 mA, and the peak power efficiency is 89.68% under 300-mA load current. The chip area is only 1.0376 mm × 1.0599 mm (include PADs).
Auteurs: Jiann-Jong Chen;Yuh-Shyan Hwang;Jian-Fong Liou;Yi-Tsen Ku;Cheng-Chieh Yu;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 2373 - 2381
Editeur: IEEE
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» A New Direction for III–V FETs for Mobile CPU Operation Including Burst-Mode: In0.35Ga0.65As Channel
Résumé:
In this letter, we show that conventional III–V MOSFETs with moderate/high In content channels (In0.53Ga0.47As or In0.70Ga0.30As) at scaled nodes are incompatible with mobile SoC designs, which often operate at intermediate/high {V_{{math\rm {dd}}}} (0.7 V to \geq 1 V) to achieve high frequency including during burst-mode. The incompatibility is due to conventional III–V FETs having too small bandgap, and thus too high leakage when operated at the increased voltages. We show that FETs with a more optimal lower In content, In0.35Ga0.65As, have the necessary combination of larger bandgap (~Si) and sufficiently high injection velocity (~2.5 times Si) to enable both low leakage and high performance (versus Si), across the entire {V_{{math\rm {dd}}}} range of mobile SoC operation. We report for the first time the growth and characterization of ultra-thin In0.35Ga0.65As FETs with a standard 1nm EOT gate dielectric. Calibrated models show that In0.35Ga0.65As enables the highest performance at very low leakages at intermediate/high {V_{{math\rm {dd}}}} in short channel FETs.
Auteurs: T. Rakshit;B. Obradovic;W.-E. Wang;W.-H. Kim;K.-M. Shin;S.-C. Baek;S.-W. Lee;S.-H. Kim;J.-M. Lee;D. Kim;A. Hoover;W.-B. Song;M. Cantoro;Y.-C. Heo;R. Rooyackers;S. C. Ardila;A. Vais;D. Lin;N. Collaert;M. S. Rodder;
Apparue dans: IEEE Electron Device Letters
Date publication: 03.-2017, volume: 38, issue:3, pages: 314 - 317
Editeur: IEEE
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» A New Distortion Correction Method for FMCW SAR Real-Time Imaging
Résumé:
A new and fast approach to correct distortion between the airborne frequency-modulated continuous wave synthetic aperture radar (FMCW SAR) real-time images is proposed in this letter. The main idea of the proposed method contains two parts. First, the rotation distortion, according to the adjacent subimages caused by the selection of the reference trajectory, is efficiently corrected by data reposition. Comparing with the conventional correction technique, the time consumption is dramatically reduced from 0.3 s to only 0.717 ms. Second, the residual offset error between the rotated subimages is analyzed and compensated in the first-step motion compensation. With the application of the proposed method, the distortion correction during FMCW SAR real-time imaging becomes realizable. The correction approach has been evaluated by an FMCW SAR system, and the obtained results verify the feasibility and effectiveness of the proposed method.
Auteurs: Chengfei Gu;Wenge Chang;Xiangyang Li;Gaowei Jia;Xinqun Luan;
Apparue dans: IEEE Geoscience and Remote Sensing Letters
Date publication: 03.-2017, volume: 14, issue:3, pages: 429 - 433
Editeur: IEEE
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» A New Era for Cities with Fog Computing
Résumé:
In this article, the authors dissect the technical challenges that cities face when implementing smart city plans and outlines the design principles and lessons learned after they carried out a flagship initiative on fog computing in Barcelona. In particular, they analyze what they call the Quadruple Silo (QS) problem -- that is, four categories of silos that cities confront after deploying commercially available solutions. Those silo categories are: physical (hardware) silos, data silos, and service management silos, and the implications of the three silos in administrative silos. The authors show how their converged cloud/fog paradigm not only helps solve the QS problem, but also meets the requirements of a growing number of decentralized services -- an area in which traditional cloud models fall short. The article exposes cases in which fog computing is a must, and shows that the reasons for deploying fog are centered much more on operational requirements than on performance issues related to the cloud.
Auteurs: Marcelo Yannuzzi;Frank van Lingen;Anuj Jain;Oriol Lluch Parellada;Manel Mendoza Flores;David Carrera;Juan Luis Pérez;Diego Montero;Pablo Chacin;Angelo Corsaro;Albert Olive;
Apparue dans: IEEE Internet Computing
Date publication: 03.-2017, volume: 21, issue:2, pages: 54 - 67
Editeur: IEEE
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» A New Framework for the Performance Analysis of Wireless Communications Under Hoyt (Nakagami- $q$ ) Fading
Résumé:
We present a novel relationship between the distribution of circular and non-circular complex Gaussian random variables. Specifically, we show that the distribution of the squared norm of a non-circular complex Gaussian random variable, usually referred to as the squared Hoyt distribution, can be constructed from a conditional exponential distribution. From this fundamental connection we introduce a new approach, the Hoyt transform method, that allows to analyze the performance of a wireless link under Hoyt (Nakagami- q ) fading in a very simple way. We illustrate that many performance metrics for Hoyt fading can be calculated by leveraging well-known results for Rayleigh fading and only performing a finite-range integral. We use this technique to obtain novel results for some information and communication-theoretic metrics in Hoyt fading channels.
Auteurs: Juan M. Romero-Jerez;F. Javier Lopez-Martinez;
Apparue dans: IEEE Transactions on Information Theory
Date publication: 03.-2017, volume: 63, issue:3, pages: 1693 - 1702
Editeur: IEEE
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» A New High-Switching-Frequency Modulation Technique to Improve the DC-Link Voltage Utilization in Multilevel Converters
Résumé:
This paper presents a new high-frequency modulation method for multilevel converters. The proposed method provides a broad linear operating range and can be digitally implemented with minimal computational effort. This modulation method creates a phase voltage composed of a rectangular component superimposed on the top of a quasi-square-shaped reference function. The reference functions are defined such that the utilization of the dc-link voltage is maximized in any modulation index, while the dv/dt of the switches is always the minimum possible value. In order to implement the proposed method, an update time that is much shorter than the fundamental period is defined in the algorithm for updating the rectangular components of the reference voltage. The high-frequency rectangular component can then be imposed on the reference function to generate the final switching function by switching between two voltage levels during the time between two update instances. Several experimental results are provided to evaluate the performance of the proposed method and to compare its operation to conventional methods.
Auteurs: Mohsen Aleenejad;Hamid Mahmoudi;Reza Ahmadi;Hossein Iman-Eini;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 1807 - 1817
Editeur: IEEE
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» A New Method for Determining the Magnetic Properties of Solid Materials Employed in Unconventional Magnetic Circuits
Résumé:
To evaluate the quality of magnetic materials used in electrical machines, accurate material characterization is required. For common, solid (nonlaminated) ferromagnetic materials, characterization procedures such as the toroidal ring sample test method are capable of mapping electromagnetic properties with reasonable accuracy. This is true when the investigation is for solid materials to be used in conventional magnetic circuits, i.e., where the flux paths and induced eddy currents follow the more common “radial” characteristics, as in a standard rotating machine. When solid ferromagnetic materials are employed in unconventional machine structures, such as for transverse flux machines or tubular linear machines, classical methods are not capable of achieving an accurate representation of the flux conditions in the machine, thus resulting in inaccurate characterization data that usually underestimate the total loss prediction. In this paper, a new testing method is proposed to impose the correct flux conditions for solid materials (used in tubular linear machines) and accurately map the eddy current losses in the solid parts. The proposed method uses a simple experimental test setup to characterize the power loss of solid, ferromagnetic material. The basic experimental results from the new setup are compared to results from three-dimensional finite element analysis.
Auteurs: Ahmed Mahmood Mohammed;Tom Cox;Michael Galea;Chris Gerada;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 2468 - 2475
Editeur: IEEE
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» A New Quality Metric for III–V/High-k MOS Gate Stacks Based on the Frequency Dispersion of Accumulation Capacitance and the CET
Résumé:
This letter proposes a metric to assess the quality of high-k dielectrics on III–V substrates and a benchmarking methodology for the gate stack qualification in the region of MOS device operation above threshold voltage, {V}_{t} . The metric is based on a capacitive equivalent thickness (CET) - normalized frequency dispersion ( text{D}_{math\rm {eff}} ) evaluated in the accumulation region of capacitance–voltage (C–V) measurements of III–V MOS devices. {D} _{math\rm {eff}} is found to be CET independent, which allows for a preliminary assessment of the dielectric quality by using relatively thick layers. Several gate stacks, single layer or bi-layer, including those with Al2O3, and the recently reported ASM-imec interfacial layer (IL) with HfO2 are evaluated and compared against Si MOS devices. Using the proposed technique, a clear difference between the various deposition processes is observed. The results indicate that the quality of a single layer Al2O3 or a bi-layer stack of Al2O3/HfO2 on InGaAs is significantly lower compared with Si gate stacks while the ASM-imec IL yields a gate-stack with good performance on the proposed quality metric. In addition, these results correlate well with the reliability performance of the studied gate stacks.
Auteurs: Abhitosh Vais;Jacopo Franco;Koen Martens;Dennis Lin;Sonja Sioncke;Vamsi Putcha;Laura Nyns;Jan Maes;Qi Xie;Michael Givens;Fu Tang;Xiaoqiang Jiang;Anda Mocuta;Nadine Collaert;Aaron Thean;Kristin De Meyer;
Apparue dans: IEEE Electron Device Letters
Date publication: 03.-2017, volume: 38, issue:3, pages: 318 - 321
Editeur: IEEE
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» A New Space-Vector-Modulation Algorithm for a Three-Level Four-Leg NPC Inverter
Résumé:
For power conversion systems interfaced to four-wire supplies, four-leg converters have become a standard solution. A four-leg converter allows good compensation of zero-sequence harmonics and full utilisation of the dc-link voltage. These are very important features when unbalanced and/or nonlinear loads are connected to the system. This paper proposes a three-dimensional space vector modulation (SVM) algorithm and provides a comprehensive analysis of the algorithm implemented on a three-level, four-leg neutral-point-clamped converter. The algorithm allows a simple definition of the different switching patterns and enables balancing of the dc-link capacitor voltages using the redundancies of the converter states. A resonant controller is selected as the control strategy to validate the proposed SVM algorithm in a 6 kW experimental rig.
Auteurs: Felix Rojas;Ralph Kennel;Roberto Cardenas;Ricardo Repenning;Jon C. Clare;Matias Diaz;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 23 - 35
Editeur: IEEE
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» A New Synthesis and Design Method for Wideband Bandpass Filters With Generalized Unit Elements
Résumé:
A new synthesis and design method for wideband bandpass filters has been proposed using the concept of generalized unit elements (GUEs). The synthesis starts with a lumped-element LC circuit, which is obtained by some well-known circuits and classic methods, such as the ladder-type circuit and the coupling matrix method. A GUE is an equivalent circuit, which is represented by either a coupled LC circuit or a section of the transmission line coupled by stubs. In this view, an LC circuit is transformed into the transmission line circuit directly via a general network of a GUE. This contributes to the key idea behind the synthesis procedure. Detailed analysis on the GUE and its equivalent circuits are discussed in terms of the equivalent characteristic impedance and the extended Richard’s transformation. Based on these two variables, frequency and constant mapping functions are proposed to explicitly obtain characteristic impedances in the transmission line circuit. In the final part, three prototype filters, namely, the classic Chebyshev ladder-type filter, the general box-shaped Chebyshev filter of symmetrical filtering responses, and the cascaded trisection filter in an asymmetrical transmission zero distribution are designed and fabricated, respectively. All the experimental results agree well with the predicted ones and thus it verifies the proposed synthesis and design method.
Auteurs: Runqi Zhang;Sha Luo;Lei Zhu;
Apparue dans: IEEE Transactions on Microwave Theory and Techniques
Date publication: 03.-2017, volume: 65, issue:3, pages: 815 - 823
Editeur: IEEE
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» A New Variational Method for Bias Correction and Its Applications to Rodent Brain Extraction
Résumé:
Brain extraction is an important preprocessing step for further analysis of brain MR images. Significant intensity inhomogeneity can be observed in rodent brain images due to the high-field MRI technique. Unlike most existing brain extraction methods that require bias corrected MRI, we present a high-order and $L_{0}$ regularized variational model for bias correction and brain extraction. The model is composed of a data fitting term, a piecewise constant regularization and a smooth regularization, which is constructed on a 3-D formulation for medical images with anisotropic voxel sizes. We propose an efficient multi-resolution algorithm for fast computation. At each resolution layer, we solve an alternating direction scheme, all subproblems of which have the closed-form solutions. The method is tested on three T2 weighted acquisition configurations comprising a total of 50 rodent brain volumes, which are with the acquisition field strengths of 4.7 Tesla, 9.4 Tesla and 17.6 Tesla, respectively. On one hand, we compare the results of bias correction with N3 and N4 in terms of the coefficient of variations on 20 different tissues of rodent brain. On the other hand, the results of brain extraction are compared against manually segmented gold standards, BET, BSE and 3-D PCNN based on a number of metrics. With the high accuracy and efficiency, our proposed method can facilitate automatic processing of large-scale brain studies.
Auteurs: Huibin Chang;Weimin Huang;Chunlin Wu;Su Huang;Cuntai Guan;Sakthivel Sekar;Kishore Kumar Bhakoo;Yuping Duan;
Apparue dans: IEEE Transactions on Medical Imaging
Date publication: 03.-2017, volume: 36, issue:3, pages: 721 - 733
Editeur: IEEE
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» A Nine-Phase Six-Terminal Concentrated Single-Layer Winding Layout for High-Power Medium-Voltage Induction Machines
Résumé:
This paper proposes a new winding layout for high-power medium-voltage nine-phase induction machines (IMs) based on a single-layer concentrated winding layout having a unity winding factor. The machine is fundamentally an asymmetrical nine-phase IM, where phases are connected in such a way as to provide six terminals that are fed from two three-phase inverters. Compared to a conventional asymmetrical six-phase IM with the same stator and copper volumes, it provides improved torque density, a higher torque/current ratio, and a simpler winding layout. Finite-element simulation is used to compare the proposed winding layout with a conventional split-phase six-phase IM to assess the claimed merits. A 1.5-hp prototype IM is also used for experimental verification. The experimental results are given under both healthy and fault conditions, where the faulty converter is completely disabled. The achievable derating factors under this case are then given and compared with those of conventional six-phase IMs.
Auteurs: Ayman S. Abdel-Khalik;Shehab Ahmed;Ahmed M. Massoud;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 1796 - 1806
Editeur: IEEE
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» A Non-Orthogonal Multiple-Access Scheme Using Reliable Physical-Layer Network Coding and Cascade-Computation Decoding
Résumé:
This paper studies non-orthogonal transmission over a $K$ -user fading multiple access channel. We propose a new reliable physical-layer network coding and cascade-computation decoding scheme. In the proposed scheme, $K$ single-antenna users encode their messages by the same practical channel code and QAM modulation, and transmit simultaneously. The receiver chooses $K$ linear coefficient vectors and computes the associated $K$ layers of finite-field linear message combinations in a cascade manner. Finally, the $K$ users’ messages are recovered by solving the $K$ linear equations. The proposed can be regarded as a generalized onion peeling. We study the optimal network coding coefficient vectors used in the cascade computation. Numerical results show the performance of the proposed approaches that of the iterative maximum $a~posteriori$ probability detection and decoding scheme, but without using receiver iteration. This results in considerable complexity reduction, processing delay, and easier implementation. Our proposed scheme significantly outperforms the iterative detection and decoding scheme with a single iteration, for example, by 1.7 dB for the two user case. The proposed scheme provides a competitive solution for non-orthogonal multiple access.
Auteurs: Tao Yang;Lei Yang;Y. Jay Guo;Jinhong Yuan;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 03.-2017, volume: 16, issue:3, pages: 1633 - 1645
Editeur: IEEE
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» A Non-Stationary Mobile-to-Mobile Channel Model Allowing for Velocity and Trajectory Variations of the Mobile Stations
Résumé:
In mobile-to-mobile (M2M) communication systems, both the transmitter and the receiver are moving with a certain velocity, which is usually assumed to be constant over time. However, in realistic propagation scenarios, the velocity of the mobile stations (MSs) is subject to changes resulting in a non-stationary fading process. In this paper, we develop a non-stationary narrow-band M2M multipath fading channel model, where the transmitter and the receiver experience changes in their velocities and trajectories. For this model, we derive expressions for the local autocorrelation function (ACF), the Wigner–Ville spectrum, the local average Doppler shift, and the local Doppler spread under isotropic scattering conditions. In addition, we investigate the correlation properties of the proposed model assuming non-isotropic scattering around the MSs. By relaxing the standard assumption of constant velocities of the MSs, this paper shows that the local ACF and the Wigner–Ville spectrum differ completely from known expressions derived for wide-sense stationary M2M channel models. Furthermore, it is shown that our model provides consistent results with respect to the Doppler spread. The proposed channel model is useful for the performance analysis of M2M communication systems under non-stationary conditions caused by velocity variations of the MSs.
Auteurs: Wiem Dahech;Matthias Pätzold;Carlos A. Gutiérrez;Néji Youssef;
Apparue dans: IEEE Transactions on Wireless Communications
Date publication: 03.-2017, volume: 16, issue:3, pages: 1987 - 2000
Editeur: IEEE
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» A Novel 4-DOF Hybrid Magnetic Bearing for DGMSCMG
Résumé:
In this paper, a novel structure of four degrees of freedom (4-DOF) hybrid magnetic bearing is proposed for double gimbal magnetically suspended control momentum gyro (DGMSCMG). It includes two active parts and one passive part, and every active part has eight stator magnetic poles around the circumference in X and Y directions, which are divided into upper and lower layers. The passive part has two whole magnetic rings, which is located in the middle of this 4-DOF hybrid magnetic bearing. The radial active force is analyzed by equivalent magnetic circuit method (EMCM) and the axial resilience force is analyzed by the infinitesimal method based on the end magnetic flux. Meanwhile, three-dimensional finite-element model of the 4-DOF hybrid magnetic bearing is established with ANSYS software, and the radial displacement versus radial force, the current versus radial force, and the axial displacement versus axial resilience force characteristics are analyzed compared with the EMCM. Furthermore, the 10 Nms DGMSCMG prototype with the proposed 4-DOF hybrid magnetic bearing is manufactured, and the experiments of the radial active force test and the axial resilience force test are carried out. Experimental results show that the presented 4-DOF hybrid magnetic bearing has good force performance and verify the correctness of the theoretical analysis.
Auteurs: Jinji Sun;Ziyan Ju;Cong Peng;Yun Le;Hongliang Ren;
Apparue dans: IEEE Transactions on Industrial Electronics
Date publication: 03.-2017, volume: 64, issue:3, pages: 2196 - 2204
Editeur: IEEE
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» A Novel and Fast SimRank Algorithm
Résumé:
SimRank is a widely adopted similarity measure for objects modeled as nodes in a graph, based on the intuition that two objects are similar if they are referenced by similar objects. The recursive nature of SimRank definition makes it expensive to compute the similarity score even for a single pair of nodes. This defect limits the applications of SimRank. To speed up the computation, some existing works replace the original model with an approximate model to seek only rough solution of SimRank scores. In this work, we propose a novel solution for computing all-pair SimRank scores. In particular, we propose to convert SimRank to the problem of solving a linear system in matrix form, and further prove that the system is non-singular, diagonally dominate, and symmetric definite positive (for undirected graphs). Those features immediately lead to the adoption of Conjugate Gradient (CG) and Bi-Conjugate Gradient (BiCG) techniques for efficiently computing SimRank scores. As a result, a significant improvement on the convergence rate can be achieved; meanwhile, the sparsity of the adjacency matrix is not damaged all the time. Inspired by the existing common neighbor sharing strategy, we further reduce the computational complexity of the matrix multiplication and resolve the scalable issues. The experimental results show our proposed algorithms significantly outperform the state-of-the-art algorithms.
Auteurs: Juan Lu;Zhiguo Gong;Xuemin Lin;
Apparue dans: IEEE Transactions on Knowledge and Data Engineering
Date publication: 03.-2017, volume: 29, issue:3, pages: 572 - 585
Editeur: IEEE
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» A Novel Broadband Dual Circularly Polarized Microstrip-Fed Monopole Antenna
Résumé:
A broadband dual circularly polarized (CP) planar monopole antenna is presented in this communication. The antenna is fed by dual orthogonal microstrip lines for polarization diversity. Circular polarization is achieved with a modified ground-plane structure and the isolation between the ports is improved by extending a protruded strip between the feed lines. L-shaped strips (LSSs) and inverted LSSs are designed along the radiating edges of the monopole. The combination of these two strips maximizes the axial ratio (AR) bandwidth, when they are placed $lambda _{g}$ /4 apart at center frequency of the CP band. This principle is verified by fabricating the prototype on a 1-mm-thick FR4 substrate with 32 mm $times32$ mm lateral dimension. From the experimental results, it is observed that the 3-dB AR bandwidth of the proposed antenna is 80.7% (3.74–8.8 GHz). The gain, return loss, and port isolation are higher than 1, 10, and 20 dB, respectively, within the CP band.
Auteurs: Chandu DS;S. S. Karthikeyan;
Apparue dans: IEEE Transactions on Antennas and Propagation
Date publication: 03.-2017, volume: 65, issue:3, pages: 1410 - 1415
Editeur: IEEE
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» A Novel Cache-Utilization-Based Dynamic Voltage-Frequency Scaling Mechanism for Reliability Enhancements
Résumé:
We propose a cache architecture using a 7T/14T SRAM (Fujiwara et al., 2009) and a control mechanism for reliability enhancements. Our control mechanism differs from conventional dynamic voltage-frequency scaling (DVFS) methods in that it considers not only the cycles per instruction behaviors but also the cache utilization. To measure cache utilization, a novel metric is proposed. The experimental results show that our proposed method achieves 1000 times less bit-error occurrences compared with conventional DVFS methods under the ultralow-voltage operation. Moreover, the results indicate that our proposed method surprisingly not only incurs no performance and energy overheads but also achieves on average a 2.10% performance improvement and a 6.66% energy reduction compared with conventional DVFS methods.
Auteurs: Yen-Hao Chen;Yi-Lun Tang;Yi-Yu Liu;Allen C.-H. Wu;TingTing Hwang;
Apparue dans: IEEE Transactions on Very Large Scale Integration Systems
Date publication: 03.-2017, volume: 25, issue:3, pages: 820 - 832
Editeur: IEEE
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» A Novel Centralized PV Power Plant Controller for Reducing the Voltage Unbalance Factor at Transmission Level Interconnection
Résumé:
This paper presents a novel centralized positive and negative sequence control strategy for enhancing the unbalanced operation of electric transmission networks. The proposed control strategy is deployed as an effective ancillary service provided by a photovoltaic power plants. The excess capacity of grid-tied inverters is utilized based on a novel centralized positive and negative sequence reactive current division algorithm. The control strategy dynamically allocates the amount of reactive power compensated by each inverter in the power plant according to its active power generation level. The performance of the proposed control strategy is evaluated for a photovoltaic power plant connected to the IEEE 12-bus Flexible AC Transmission Systems test system in steady-state and transient operation. This is demonstrated through unbalanced loads and asymmetrical grid faults. The proposed control strategy effectively reduced the voltage unbalance factor within the acceptable operating limits, and enhanced the transient response at the transmission level interconnection. This is achieved in order to adhere to grid codes’ requirements and the IEC 61000-3-13 standard.
Auteurs: Nada Al Awadhi;Mohamed Shawky El Moursi;
Apparue dans: IEEE Transactions on Energy Conversion
Date publication: 03.-2017, volume: 32, issue:1, pages: 233 - 243
Editeur: IEEE
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