Publications dans les journaux scientifiques dans le domaine de l'ingénierie : 07-2010 trié par par titre, page: 0 |
| » 'Operational health' monitoring for confidence in long term electric field measurements |
Résumé:
The paper describes practical aspects of electrostatic fieldmeter instrumentation for long term monitoring of electric fields in adverse environmental conditions. Examples of applications have been in studies of tank washing on large crude oil tankers and measurement of atmospheric electric fields. Particular attention is drawn to the technique developed for continuous monitoring of operational health to justify confidence in observations. |
| Auteurs: John, Chubb , John, Harbour |
| Apparue dans: Journal of Electrostatics |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » 0.8?W 12-bit SAR ADC sensors interface for RFID applications |
Résumé:
The design and first measuring results of an ultra-low power 12 bit successive-approximation ADC for autonomous multi-sensor systems are presented. The comparator and the DAC are optmised for low power consumption. The power consumption is 0.52?W from a 1.2V supply with a sample clock of 3.125kHz and 0.85?W at 6.25kHz. This gives 136pJ per conversion or 66fJ per conversion step. As per authors' knowledge, 66fJ per conversion step is the best reported so far.The ADC was realised in the NXP CMOS 0.14?m technology; the area was 0.35mm2. Only four metal layers were used in order to allow 3D integration of... |
| Auteurs: Daniela, De Venuto , David Tio, Castro , Youri, Ponomarev , Eduard, Stikvoort |
| Apparue dans: Microelectronics Journal |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » 100 Gb/s optical access based on optical orthogonal frequency-division multiplexing |
Résumé:
The ever-increasing bandwidth demand in access systems is catalyzing research and development activity in future ultra high-speed 100 Gb/s passive optical networks. In this article we discuss the principles, key advantages, and most recent demonstrations of a record 100 Gb/s OFDM-based PON as a future PON candidate architecture. Moreover, we provide an analysis of primary cost factors in a practical DSP-based OFDMA-PON implementation and survey the most recent achievements in this domain. Due to the combination of highly attractive advanced features and favorable related trends in longhaul 100 Gb/s fiber transmission, OFDMA-PON can be regarded as a very promising solution for future PON-based access. |
| Auteurs: Cvijetic, N.;Dayou Qian;Junqiang Hu; |
| Apparue dans: IEEE Communications Magazine |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 70 - 77 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » 100 gigabit Ethernet transport: Part 2 [Guest editorial] |
Résumé:
Over the past year, the development of 100 Gb/s per wavelength systems have moved from laboratory demonstrations to field trials to commercial deployment. In two previous issues of IEEE Communications Magazine on 100 Gb/s Ethernet (100GbE), we covered the key enabling technologies, implementation issues, network requirements, and field experiments. In this third installment of our series on 100GbE, we continue our investigation, contributing articles on network design issues, access technology, digital signal processing requirements, and more field trial results. We also explore technology trends for next-generation systems beyond 100 Gb/s per wavelength. |
| Auteurs: Wellbrock, G.;Wang, T.;Ishida, O.; |
| Apparue dans: IEEE Communications Magazine |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 24 - 24 |
| Editeur: IEEE |
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| » 100G and beyond with digital coherent signal processing |
Résumé:
The demand for increased bandwidth is ever present. Coherent technology coupled with advanced modulation formats and digital signal processing is a key enabler for optical communication systems at 100 Gb/s and beyond. This article reviews the attributes of coherent systems in light of the challenges faced by system designers to realize increased bit rates for next-generation optical systems. |
| Auteurs: Roberts, K.;Beckett, D.;Boertjes, D.;Berthold, J.;Laperle, C.; |
| Apparue dans: IEEE Communications Magazine |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 62 - 69 |
| Editeur: IEEE |
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| » 100G Ethernet and OTU4 testing challenges: From the lab to the field |
Résumé:
The combination of digital media, personal computing, and global networking is creating a radical shift in the telecom industry. However, the transport backbone, which was built on 10G wavelengths, is nearing capacity and is driving the need for upgrades to 40G and 100G. 100G Ethernet and OTU4 bring new fundamental concepts, which require new training and new testing. 100G Ethernet and OTU4 equipment is currently in development or in trial, and the next phase is to deploy this equipment in the field. This article is mostly based on the work done by IEEE P802.3ba and ITU-T Study Group 15 to provide an overview of how 100G Ethernet and OTU4 are different from previous technologies, and includes guidance on which tests need to be performed with these emerging technologies. 112G line side testing is also briefly discussed. |
| Auteurs: Drolet, P.;Duplessis, L.; |
| Apparue dans: IEEE Communications Magazine |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 78 - 82 |
| Editeur: IEEE |
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| » 2:1 Candidate Position Subsampling Technique for Fast Optimal Motion Estimation |
Résumé:
The candidate position subsampling technique (CPST) basically chooses candidates in a search window at a sampling rate. The 2:1 CPST chooses half the candidates, and then selects one or more candidates that are considered as to be close to the optimal motion vector before conducting a fine search. The fine search is conducted by checking four neighbors of the chosen candidate(s) referred to as winner(s). The CPST can be combined with a fast optimal block-matching algorithm, such as the multilevel successive elimination algorithm (MSEA), in order to reduce the number of computations used in rejecting the non-best candidate. We propose a new 2:1 CPST fitted to the MSEA. The proposed algorithm adopts a new condition for the winner which helps to find the best candidate efficiently. Moreover, a fast motion estimation step is used to reduce the number of computations of the MSEA, and the peak signal-to-noise ratio (PSNR) compensation step is adopted to guarantee that the PSNR performance of the proposed algorithm is very close to that of the full search. Experimental results show that the proposed algorithm reduces the computational loads of the MSEA by 47.26% on average with only ${-}{rm 0.027}~{rm dB}$ PSNR degradation in the worst case. |
| Auteurs: Lee, H.-S.;Jung, J.-H.;Park, D.-J.; |
| Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 1052 - 1056 |
| Editeur: IEEE |
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| » 3-D FIR Cone-Shaped Filter Design by a Nest of McClellan Transformations and Its Variable Design |
Résumé:
In this paper, the technique of a nest of McClellan transformations is proposed for the design of 3-D FIR cone- shaped filters. First, a transformation subfilter for fan-type mapping is found. Then the cosine term of a frequency variable of the above transformation subfilter is replaced by an embedded transformation subfilter which possesses circular contours. The technique stated above is also extended to design 3-D FIR variable cone-shaped filters such that the inclination of the cone-shaped filters can be adjusted online. Moreover, an efficient structure is proposed for the implementation of the designed filters. Several examples will be presented to demonstrate the effectiveness of the proposed method. |
| Auteurs: Shyu, J.-J.;Pei, S.-C.;Huang, Y.-D.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1697 - 1707 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » 3-D medical image compression usiNG 3-D wavelet coders |
Résumé:
This paper presents compression of 3-D medical images using 3-Dwavelet encoders. Four wavelet transforms, namely, Daubechies 4, Daubechies 6, Cohen-Daubechies-Feauveau 9/7 and Cohen-Daubechies-Feauveau 5/3 are used in the first stage with encoders such as 3D SPIHT, 3D SPECK and 3D BISK are used in the second stage for the compression and the optimal wavelet-encoder combination is identified. Two versions of wavelet transform, symmetric and decoupled wavelet transform are considered. Experiments are performed using medical test images such as magnetic resonance images (MRI) and x-ray angiograms (XA). The performances of the proposed scheme are evaluated in terms of peak signal to... |
| Auteurs: N., Sriraam , R., Shyamsunder |
| Apparue dans: Digital Signal Processing |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » 3-D numerical analysis of EHD turbulent flow and mono-disperse charged particle transport and collection in a wire-plate ESP |
Résumé:
The present study attempts to develop a detailed numerical approach and a simulation procedure to predict the motion of gas, ions and particles inside a simple parallel plate channel containing a single corona wire. A hybrid FEM-FCT-FVM method is used: the FEM-FCT numerical algorithm is applied for modeling the steady-state corona discharge, while the turbulent gas flow and the particle motion under electrostatic forces are modeled using the commercial CFD code FLUENT. Calculations for the gas flow are carried out by solving the Reynolds-averaged Navier-Stokes equations and turbulence is modeled using the k-? turbulence model. An additional source term is... |
| Auteurs: Niloofar, Farnoosh , K., Adamiak , G.S.P., Castle |
| Apparue dans: Journal of Electrostatics |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » 325 GHz Single Layer Sub-Millimeter Wave FSS Based Split Slot Ring Linear to Circular Polarization Convertor |
Résumé:
A single layer, frequency selective surface based, sub-millimeter wave transmission polarizer is presented that converts incident slant linear 45° polarization into circular polarization upon transmission. The polarization convertor consists of a 30 mm diameter 10 thick silicon reinforced metalized screen containing 2700 resonator cells and perforated with nested split ring slot apertures. The screen was designed and optimized using CST Microwave Studio and predictions were validated experimentally by transmission measurements over the 250-365 GHz frequency range. This frequency range is used for remote environmental monitoring and 325 GHz represents a molecular emission line for H2O. The results obtained show good agreement between measured and modeled predictions. The measured 3 dB axial ratio bandwidth was 11.75%, measured minimum Axial Ratio was 0.19 dB and the measured insertion loss of the single layer screen was 3.38 dB. |
| Auteurs: Euler, M.;Fusco, V.;Cahill, R.;Dickie, R.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2457 - 2459 |
| Editeur: IEEE |
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| » 3D Nonlinear Super-Resolution Microwave Inversion Technique Using Time-Domain Data |
Résumé:
A nonlinear three-dimensional full-wave inverse scattering method using time-domain data and models is presented. It successfully reconstructs 3D images of various unknown objects using time-domain data. The method uses Born-type iterations and a constrained minimization to reconstruct successively improved images. The use of time-domain data allows very few transmitters and receivers to be used. It is shown that this technique achieves super-resolution, namely 0.1 wavelength. The method is able to recover contrasts of over 2:1. It can also recover objects with minute contrasts of as low as 10%, thus taking a step towards addressing recent findings in the breast cancer imaging community, for example, that some breast tumors have only a 10% contrast with respect to the glandular tissues. This method could present a promising tool for the early-stage breast cancer detection as well as other medical and subsurface imaging applications. |
| Auteurs: Ali, M.A.;Moghaddam, M.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2327 - 2336 |
| Editeur: IEEE |
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| » 60 GHz beamforming using in-package bondwire antenna array |
Résumé:
An antenna array using in-package bondwire to perform beamforming for 60 GHz applications is presented. 1 mil gold bondwire designed to resonate at 60 GHz was employed as an antenna array to provide smaller area and a cheaper way to manufacture it. The overall size of the bondwire antenna array on a CMOS chip is 1 x 3 mm2 and its radiation pattern shows fair agreement with simulation results. |
| Auteurs: Jeong, Y.S.;Kang, M.K.;Kim, T.W.; |
| Apparue dans: Electronics Letters |
| Date publication: 07.-2010, volume: 46, issue:15, pages: 1047 - 1048 |
| Editeur: IEEE |
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| » 68–110-GHz-Band Low-Noise Amplifier Using Current Reuse Topology |
Résumé:
This paper proposes a new topology for a broadband low-noise-amplifier (LNA). A common-gate (CG) amplifier with a matching inductor composes a unit cell, and the unit cells are cascaded to increase gain. As both the input and output impedances of the unit cell are matched to 50 $Omega$ for a wide frequency range, it is possible to increase the gain while maintaining wide bandwidth. Thus, high-gain and broadband performance can be obtained using this topology. The other features of the amplifier are its small size, low power consumption, and current reuse topology. This paper presents the design methodology of a multistage CG amplifier with a matching inductor. Fabricated in an 80-nm InP HEMT process, we developed an ultra-broadband LNA. The LNA with a three-stage CG amplifier exhibited a gain of 18 dB and a noise figure of 3.5 dB from 68 to over 110 GHz. The power consumption was 12 mW under a power supply voltage of 3 V. The chip size is 0.55$,times,$ 0.75 mm$^{2}$ . Furthermore, we developed a receiver for passive millimeter-wave imagers by integrating a six-stage LNA with a power detector. The chip size of the receiver is 1.1$,times,$ 0.75 mm$^{2}$ . The sensitivity of the pre-amplified detector was more than 2 000 V/mW from 75 to 100 GHz. These results show that the topology is one of the best candidates for high-gain and broadband LNA with small size and low power consumption. |
| Auteurs: Sato, M.;Takahashi, T.;Hirose, T.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1910 - 1916 |
| Editeur: IEEE |
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| » In Situ Doped Source/Drain for Performance Enhancement of Double-Gated Poly-Si Nanowire Transistors |
Résumé:
A poly-Si nanowire (NW) thin-film transistor configured with the double-gated scheme was fabricated and characterized. The fabrication process features the clever use of selective plasma etching to form a rectangular NW underneath a hard mask. In this paper, we show that replacing the original ion-implanted poly-Si with in situ doped poly-Si for the source/drain significantly enhances the device performance, including steeper subthreshold swing (SS), larger on/off current ratio, and reduced series resistance. In particular, the SS is improved to a record-breaking low value of 73 mV/dec, which, to the best of our knowledge, is the most ideal ever reported for a poly-Si based device. The new NW transistors with such excellent switching properties are highly promising for reducing power consumption and operational voltage in practical circuit applications. |
| Auteurs: Chen, W.-C.;Lin, H.-C.;Chang, Y.-C.;Lin, C.-D.;Huang, T.-Y.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1608 - 1615 |
| Editeur: IEEE |
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»  -Channel Multiple Description Coding With Two-Rate Coding and Staggered Quantization |
Résumé:
A low complexity $M$-channel multiple description coding scheme is developed in this paper, in which each description carries one subset of the input with a higher bit rate and the rest with a lower bit rate. The lower-rate codings in different descriptions are designed to be mutually refinable using staggered scalar quantizers. For correlated sources, a two-rate predictive coding is used in each description. Closed-form expressions of the distortions are derived when different numbers of descriptions are received. The application of the proposed scheme in lapped transform based image coding is also investigated, and the optimal transform is obtained. Experimental results using both 1-D memoryless sources and 2-D images demonstrate the superior performance of the proposed scheme. |
| Auteurs: Samarawickrama, U.;Liang, J.;Tian, C.; |
| Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 933 - 944 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A 0.5-Hz High-Pass Cutoff Dual-Loop Transimpedance Amplifier for Wearable NIR Sensing Device |
Résumé:
This brief describes a fully integrated dual-loop transimpedance amplifier with bandpass response for wearable near-infrared (NIR) sensing operating at low frequency: one loop to lower the lower band cutoff frequency and another loop for self-regulating DC photocurrent to prevent saturation at later stages. The circuit was implemented in a 0.35-$muhbox{m}$ CMOS process and achieved a DC photocurrent rejection ranging from 2.7 to 15 $muhbox{A}$ and a $-$3-dB high-pass cutoff frequency from 0.5 to 110 Hz by using on-chip capacitors. Both total harmonic distortion and spurious-free dynamic range are better than $-$42 dB. It achieves an improvement of 390 times in capacitor reduction compared with the traditional DC rejection technique. |
| Auteurs: Wong, A. K. Y.;Leung, K. N.;Pun, K.-P.;Zhang, Y.-T.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 531 - 535 |
| Editeur: IEEE |
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| » A 10-mW Submillimeter-Wave Solid-State Power-Amplifier Module |
Résumé:
In this paper, we demonstrate a packaged sub-millimeter wave solid-state power amplifier (SSPA). The SSPA is implemented in coplanar waveguide (CPW) and uses an advanced high ${ f}_{rm MAX}$ InP HEMT transistor with a sub 50-nm gate. A monolithically integrated CPW dipole-to-waveguide transition eliminates the need for wirebonding and additional substrates. On-chip compact tandem couplers are used for power combining. The amplifier demonstrates 15-dB small-signal gain at 340 GHz. Peak saturated output power of 10 mW at 338 GHz is obtained at the waveguide flange output for the SSPA module. |
| Auteurs: Radisic, V.;Deal, W. R.;Leong, K. M. K. H.;Mei, X. B.;Yoshida, W.;Liu, P.-H.;Uyeda, J.;Fung, A.;Samoska, L.;Gaier, T.;Lai, R.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1903 - 1909 |
| Editeur: IEEE |
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» A 2-D Artificial Dielectric With  for the Terahertz Region |
Résumé:
We demonstrate a 2-D artificial dielectric medium suitable for the terahertz region by exploiting the characteristic frequency dependence in the phase velocity of the lowest order transverse-electric $({rm TE}_{1})$ mode of the parallel-plate waveguide (PPWG). This artificial medium exhibits a plasma-like behavior having a frequency-dependent refractive index that varies between zero and unity. Using this medium, we demonstrate the optical phenomena of total internal reflection and Brewster's effect, and also demonstrate a convergent PPWG-lens. |
| Auteurs: Mendis, R.;Mittleman, D. M.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1993 - 1998 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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» A 20 GS/s 1.2 V 0.13  CMOS Switched Cascode Track-and-Hold Amplifier |
Résumé:
A low voltage, low power, high sampling rate trackand-hold amplifier (THA) architecture is proposed. The THA samples at 20 GS/s and combines a distributed amplifier and a switched cascode stage. Power consumption for the circuit is 71 mW and it occupies 0.09 $hbox{mm}^{2}$ in 0.13 $muhbox{m}$ CMOS. The THA delivers up to 34 dB spur-free dynamic range (SFDR) and $-$32 dB total harmonic distortion (THD) at a supply voltage of 1.2 V. Input return loss remains below $-$ 10 dB over all frequencies of interest, while output return loss remains below $-$15 dB. |
| Auteurs: Orser, H.;Gopinath, A.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 512 - 516 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A 3-D Ritz solution for free vibration of circular/annular functionally graded plates integrated with piezoelectric layers |
Résumé:
This paper addresses three-dimensional (3-D) free vibration characteristic of thick circular/annular functionally graded (FG) plates with surface-bonded piezoelectric layers on the basis of 3-D Ritz solution. Three displacement components along with electrical potential field of the plate are expressed by a set of Chebyshev polynomials multiplied by geometry boundary functions. Both open-circuit and closed-circuit surface conditions are taken into account. The mechanical properties of the FG plates are assumed to vary continuously through the thickness of the plate and obey either exponent or power law distribution of the volume fraction of the constituents. The effect of thickness-to-radius ratio, inner-to-outer radius... |
| Auteurs: Sh., Hosseini-Hashemi , M., Azimzadeh-Monfared , H., Rokni Damavandi Taher |
| Apparue dans: International Journal of Engineering Science |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » A 520–590 GHz Crossbar Balanced Fundamental Schottky Mixer |
Résumé:
We report on the design and performance of a crossbar broadband, biasable, balanced fundamental 520-590 GHz fix-tuned frequency mixer that utilizes planar Schottky diodes. The suspended stripline circuit is fabricated on a GaAs membrane mounted in a split waveguide block. The chip is supported by thick beam leads that are also used to provide precise RF grounding, RF coupling and DC/IF connections. At room temperature, the mixer has a measured DSB noise temperature of 2200 K at the low end of the band, and less than 4000 K across the design band. |
| Auteurs: Schlecht, E.T.;Gill, J.J.;Lin, R.H.;Dengler, R.J.;Mehdi, I.; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 387 - 389 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A 56.5–72.2 GHz Transformer-Injection Miller Frequency Divider in 0.13 $mu{rm m}$ CMOS |
Résumé:
A V-band Miller frequency divider with a locking range of 15.7 GHz (f0 = 64 GHz) is realized in 0.13 μm CMOS technology. Using the proposed transformer-injection technique, the signal can be injected into the mixer core directly without the current and impedance limitations of the input stage. The divider also features a fully differential topology. Under the condition of VDD = 0.9 V, the divider can even function with a power dissipation of only 0.81 mW. |
| Auteurs: Wei-Sung Chang;Kai-Wen Tan;Hsu, S.S.H.; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 393 - 395 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A 60 GHz-Standard Compatible Programmable 50 GHz Phase-Locked Loop in 90 nm CMOS |
Résumé:
This letter presents, for the first time, a 60 GHz four-channel standard compatible heterodyne frequency synthesizer solution with low-cost reference signal. The presented PLL features a dual-core varactor-based LC cross-coupled voltage-controlled oscillator (VCO). The measured phase noise is -80.1 dBc/Hz at 1 MHz offset, and it is limited by the phase noise of the reference signal. The measured output spectrum shows spur suppression higher than 32 dBc. Using the lowest reference frequency to date (27 MHz), the presented PLL is suitable for applications in low cost fully integrated multi-gigabit 60 GHz CMOS radio transceivers. |
| Auteurs: Barale, F.;Sen, P.;Sarkar, S.;Pinel, S.;Laskar, J.; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 411 - 413 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A 800Mb/s CMOS detection scheme for UWB impulse-radio communication |
Résumé:
A CMOS detection procedure for ultra-wideband impulse radio (UWB-IR) communication system, employing Bi-Phase Shift Keying (BPSK) modulation scheme, is presented here. The chip, designed and fabricated in a 0.18 CMOS process, requires a supply voltage of 1.8V and occupies a die area of 0.01mm2. A train of Gaussian monocycle pulses (GMP), modulated by a random data sequence of 800Mb/s, is detected successfully by the detector. The detection scheme employing a very simple architecture with a power consumption of 3mW is well suited for non-coherent wireless communication system. |
| Auteurs: Mohiuddin, Hafiz , Nobuo, Sasaki , Takamaro, Kikkawa |
| Apparue dans: AEU - International Journal of Electronics and Communications |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » A 9-bit 80 MS/s Successive Approximation Register Analog-to-Digital Converter With a Capacitor Reduction Technique |
Résumé:
A 9-bit 80 MS/s successive approximation register analog-to-digital converter (ADC), which is suitable for low power and a small area, is presented. The 9-bit capacitor array consists of only 16 unit capacitors and a coupling capacitor due to the proposed binary-weighted split-capacitor arrays with a merged-capacitor switching technique. The proposed ADC includes a comparator with offset cancellation and uses digital calibration for error correction. The ADC is implemented in a 65-nm complimentary metal–oxide–semiconductor technology and occupies an active area of 0.068 $hbox{mm}^{2}$ with a reference buffer. The differential and integral nonlinearities of the ADC are less than 0.37 and 0.40 LSB, respectively. The ADC shows a signal-to-noise-distortion ratio of 50.71 dB, a spurious-free dynamic range of 66.72 dB, and an effective number of bits of 8.13 bits with a 78 MHz sinusoidal input at 80 MS/s. The ADC consumes 3.4 mW with the reference buffer at a 1.0-V supply and achieves a figure of merit of 78 fJ/conversion step. |
| Auteurs: Cho, Y.-K.;Jeon, Y.-D.;Nam, J.-W.;Kwon, J.-K.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 502 - 506 |
| Editeur: IEEE |
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» A  to  Bidirectional I/O Buffer With a Dynamic Gate Bias Generator |
Résumé:
This paper presents a wide-range I/O buffer able to transmit and receive signals of 0.9/1.2/1.8/3.3/5.0 V by using a typical ${0.18}~mu{hbox {m}}$ CMOS process. The Dynamic gate bias circuit in the proposed I/O buffer is composed of two voltage converters, an EOS (Electrical Overstress) protector, and standard logic cells. A High voltage detector detects voltage level of VDDIO and then generates several bias voltages to the Dynamic gate bias circuit. By using the Dynamic gate bias generator to generate appropriate gate drives for the triple-stacked MOS transistors in the Output stage, the gate-oxide overstress and hot-carrier degradation are avoided. A Floating N-well circuit in the proposed I/O buffer is used to remove undesirable leakage current paths. The proposed I/O buffer can operate at 10/40/50/40/10 MHz when VDDIO are biased at 5.0/3.3/1.8/1.2/0.9 V, respectively. The maximum speed is 50 MHz given a 19 pF load. The maximum static power consumption is merely ${3.9}~mu{rm W}$ justified by the measurements on silicon. |
| Auteurs: Wang, C.-C.;Hsu, C.-H.;Liu, Y.-C.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1642 - 1653 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Bayesian Reconstruction Method with Marginalized Uncertainty Model for Camera Motion in Microrotation Imaging |
Résumé:
Reconstruction of a 3-D structure from multiple projection images requires prior knowledge of projection directions or camera motion parameters that describe the relative positions and orientations of 3-D structure with respect to the camera. These parameters can be estimated using, for instance, the conventional correlation alignment and feature-based methods. However, the alignment methods are not perfect, where the inaccuracy of the estimated motion parameters causes artifacts in the reconstruction. To overcome this problem, we propose a Bayesian approach to reconstruct the object that takes the motion uncertainty distribution into account. Moreover, we consider the motion parameters as nuisance parameters and integrate them out from the posterior distribution, assuming a Gaussian uncertainty model, which yields a statistical cost function to be minimized. The proposed method is applied in microrotation fluorescence imaging, where we aim at 3-D reconstruction of a rotating object from an image series, acquired by an optical microscope. The experiments with simulated and real microrotation datasets demonstrate that the proposed method provides visually and numerically better results than the traditional reconstruction methods, which ignore the uncertainty of the motion estimates. |
| Auteurs: Laksameethanasan, D.;Brandt, S. S.; |
| Apparue dans: IEEE Transactions on Biomedical Engineering |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1719 - 1728 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Behavior Model of a Dickson Charge Pump Circuit for Designing a Multiple Charge Pump System Distributed in LSIs |
Résumé:
This brief discusses how each of multiple charge pump circuits in LSIs is designed in case where the power and ground line resistance is not negligible. A behavior model for a charge pump, including the local power and ground voltages as input parameters, is proposed and a systematic design methodology is then presented. A system designer can use the behavior model to determine the specifications on each pump and power and ground resistance for minimizing overall area. |
| Auteurs: Tanzawa, T.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 527 - 530 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A bend loss-based singlemode fiber microdisplacement sensor |
Résumé:
An all-fiber displacement sensor with a simple configuration is proposed and investigated theoretically and experimentally. The proposed fiber displacement sensor consists of a half-loop structure of high-bend loss singlemode fiber-1060XP. A ratiometric power measurement system for interrogating the proposed sensor is also presented. By measuring the change in ratio of bend loss in the ratiometric measurement system, a change in displacement can be measured assuming the ratiometric system is calibrated. The proposed macrobending fiber-based displacement sensor achieves a competitive resolution of circa 0.3 [mu]m and also benefits from simplicity compared with conventional fiber Bragg grating-based displacement sensor. The displacement sensor is sensitive to temperature and an experimental investigation of this sensitivity is presented. It is found that the ratio response has a linear variation with temperature; therefore, temperature dependence can be mitigated by a suitable correction process. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2231-2235, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25446 |
| Auteurs: Pengfei Wang, Yuliya Semenova, Qiang Wu, Gerald Farrell |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A bibliography of the literature on process capability indices: 2000-2009 |
Résumé:
This paper contains a bibliography of approximately 530 journal papers and books on process capability indices for the period 2000-2009. The related literature is classified into four major categories, namely, books, review/overview papers, theory- and method-related papers, and special applications. Theory- and method-related papers are further classified into univariate and multivariate cases, and special applications include acceptance sampling plans, supplier selection, and tolerance design and other optimizations. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Bong-Jin Yum, Kwan-Woo Kim |
| Apparue dans: Quality and Reliability Engineering International |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Broadband 835–900-GHz Fundamental Balanced Mixer Based on Monolithic GaAs Membrane Schottky Diodes |
Résumé:
The development of a 835–900-GHz biasable fundamental balanced mixer using planar GaAs Schottky diodes is presented. The monolithic microwave integrated circuit integrates two planar Schottky anodes in a balanced configuration, stripline filtering elements, and on-chip capacitor on a thin GaAs membrane. At 850 GHz, double side-band (DSB) mixer noise temperature of 2660 K and conversion loss of 9.25 dB are measured, respectively, at room temperature. When the mixer is cooled to 120 K, the DSB mixer noise temperature and conversion loss improve to 1910 K and 8.84 dB, respectively. |
| Auteurs: Thomas, B.;Maestrini, A.;Gill, J.;Lee, C.;Lin, R.;Mehdi, I.;de Maagt, P.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1917 - 1924 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Broadband Folded Printed Quadrifilar Helical Antenna Employing a Novel Compact Planar Feeding Circuit |
Résumé:
A broadband printed quadrifilar helical antenna employing a novel compact feeding circuit is proposed in this paper. This antenna presents an excellent axial ratio over a wide beamwidth, with a 29% bandwidth. A specific feeding circuit based on an aperture-coupled transition and including two 90° surface mount hybrids has been designed to be integrated with the quadrifilar antenna. Over the bandwidth, the measured reflection coefficient of the antenna fed by the wideband compact circuit has been found to be equal to or lower than -12 dB and the maximum gain varies between 1.5 and 2.7 dBic from 1.18 to 1.58 GHz. The half-power beamwidth is 150°, with an axial ratio below 3 dB over this range. The compactness of the feeding circuit allows small element spacing in array arrangements. |
| Auteurs: Caillet, M.;Clénet, M.;Sharaiha, A.;Antar, Y.M.M.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2203 - 2209 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Built-In-Test Circuit for RF Differential Low Noise Amplifiers |
Résumé:
This paper presents an efficient, low-cost, built-in test (BIT) circuit for radio frequency differential low noise amplifiers (DLNAs). The BIT circuit detects amplitude alterations at the outputs of the DLNA, due to parametric or catastrophic faults, and provides a single digital Pass/Fail indication signal. A triple modular redundancy approach has been adopted for the BIT circuit design to avoid possible yield loss in case of a malfunctioning test circuitry. The technique has been evaluated on a typical CMOS RF DLNA and simulation results are presented. |
| Auteurs: Dermentzoglou, L.;Arapoyanni, A.;Tsiatouhas, Y.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1549 - 1558 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Case for Optimized Protocols in the Creation of a Smarter Grid |
Résumé:
The design trades made in choosing an appropriate protocol for the conveyance of meter data are discussed. The paper identifies “context” as the mechanism by which communication efficiencies are sometimes obtained. This paper concludes that while generalized protocols are commonly used to communicate between utility back-office applications, specialized protocols can yield an optimum solution when reaching endpoints. |
| Auteurs: Haynes, D. D.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1476 - 1482 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Century of Development in Applied Electrostatics [History] |
Résumé:
To most electrical engineers, the term electrostatics brings to mind some hazy visions of early electrical experimentation involving an ancient Greek, a dead cat, and a piece of amber. Many of us recreated this quaint demonstration of triboelectric charging and its subsequent attraction in high school physics class. Perhaps some, in more enlightened schools, substituted modern materials such as plastics and synthetic fibers. In university electrical engineering programs, electrostatics is usually ignored or relegated to mathematical simplifications involving quasi-electrostatic approximations of important applications in electromagnetics. Meanwhile, a serious work involves the state-of-the-art study of topics such as electrodynamics and digital electronics. These fields have dominated so many important advances in the 20th century. |
| Auteurs: Castle, G.S.P.; |
| Apparue dans: IEEE Industry Applications Magazine |
| Date publication: 07.-2010, volume: 16, issue:4, pages: 8 - 13 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Channel-Estimation and Data-Detection Scheme for Multiuser MIMO-CDMA Systems in Fading Channels |
Résumé:
In this paper, we examine the effect of channel estimation errors on the performance of multiple-input–multiple-output (MIMO) systems that employ code-division multiple-access (CDMA) transmission. Channel estimation based on training techniques has widely been considered throughout the literature. However, employing these training techniques in MIMO-CDMA systems degrades system performance due to multiuser interference. This degradation is clear as the diversity advantage of the MIMO system diminishes with the increased level of interference. As a remedy to this problem, we propose a channel-estimation and data-detection scheme based on the superimposed training technique for space-time spreading systems. The proposed scheme enhances the performance of the space-time system by eliminating the interference effect from both the channel and data estimates using two decorrelators: channel and data decorrelators. We investigate the performance of the proposed estimation technique considering an asynchronous CDMA uplink transmission over frequency-selective slow-fading channels. In particular, we analyze the bit-error-rate (BER) performance of the multiuser system with two-transmit-antenna and $V$-receive-antenna configuration over Rayleigh fading channels. Compared with other conventional estimation techniques, our results show that the proposed estimation technique is more robust to channel-estimation errors. Furthermore, both simulations and analytical results indicate that full system diversity is achieved. |
| Auteurs: Assra, A.;Hamouda, W.;Youssef, A.; |
| Apparue dans: IEEE Transactions on Vehicular Technology |
| Date publication: 07.-2010, volume: 59, issue:6, pages: 2830 - 2844 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Class of Constrained Adaptive Beamforming Algorithms Based on Uniform Linear Arrays |
Résumé:
A new class of adaptive beamforming algorithms is proposed based on a uniformly spaced linear array by constraining its weight vector to a specific conjugate symmetric form. The method is applied to the well-known reference signal based (RSB) beamformer and the linearly constrained minimum variance (LCMV) beamformer as two implementation examples. The effect of the additional constraint is equivalent to adding a second step in the derived adaptive algorithm. However, a difference arises for the RSB case since no direction-of-arrival (DOA) information of the desired signal is available, which leads to a two-stage structure for incorporating the imposed constraint. Compared to the traditional algorithms, the proposed ones can achieve a faster convergence speed and a higher steady state output signal-to-interference-plus-noise ratio, given the same stepsize. |
| Auteurs: Zhang, L.;Liu, W.;Langley, R. J.; |
| Apparue dans: IEEE Transactions on Signal Processing |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 3916 - 3922 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Closed-Form Solution to Asymmetric Motion Profile Allowing Acceleration Manipulation |
Résumé:
In this paper, we propose a new complete closed-form formula for asymmetric motion profiles of long, medium, and short distances, which enables easy manipulation of jerks in arrival time for effectively reducing the acceleration and thus the overshoot. The design parameter named jerk ratio is newly introduced to scale down the jerks during the deceleration period so that the velocity profile is in an asymmetric S-curve. Owing to the jerk ratio, the motion formulas are remarkably simplified in analytic forms for short, medium, and long distances. The effectiveness of the proposed approach will be illustrated with the sledge movement control in an optical data storage system by experiments. |
| Auteurs: Rew, K.-H.;Kim, K.-S.; |
| Apparue dans: IEEE Transactions on Industrial Electronics |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 2499 - 2506 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A CMOS low-voltage low-power temperature sensor |
Résumé:
Temperature sensing circuits are used in a wide range of applications such as in the biomedical area, cold chain monitoring and industrial applications. In the biomedical area, temperature patient monitoring systems can be found in a wide range of hospital applications such as the intensive care unit, surgery rooms and clinical analysis. When the systems also incorporate also communication features, they form a telemedicine system in which the patients can be remotely monitored. The need of portability promotes a demand for sensors and signal conditioners that can be placed directly on the patient or even implanted. Implanted systems provide comfort... |
| Auteurs: Paulo Cesar, Crepaldi , Tales Cleber, Pimenta , Robson Luiz, Moreno |
| Apparue dans: Microelectronics Journal |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Collaborative Multiagent Taxi-Dispatch System |
Résumé:
This paper presents a novel multiagent approach to automating taxi dispatch that services current bookings in a distributed fashion. The existing system in use by a taxi operator in Singapore and elsewhere, attempts to increase customer satisfaction locally, by sequentially dispatching nearby taxis to service customers. The proposed dispatch system attempts to increase customer satisfaction more globally, by concurrently dispatching multiple taxis to the same number of customers in the same geographical region, and vis-à-vis human driver satisfaction. To realize the system, a multiagent architecture is proposed, populated with software collaborative agents that can actively negotiate on behalf of taxi drivers in groups of size N for available customer bookings. Theoretically, an analysis of the boundary and optimal multiagent taxi-dispatch situations is presented along with a discussion of their implications. Experimentally, the operational efficiency of the existing and proposed dispatch systems was evaluated through computer simulations. The empirical results, obtained for a 1000-strong taxi fleet over a discrete range of N , show that the proposed system can dispatch taxis with reduction in customer waiting and empty taxi cruising times of up to 33.1% and 26.3%, respectively; and up to 41.8% and 41.2% reduction when a simple negotiation speedup heuristic was applied. |
| Auteurs: Kiam Tian Seow;Nam Hai Dang;Der-Horng Lee; |
| Apparue dans: IEEE Transactions on Automation Science and Engineering |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 607 - 616 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Collaborative Recommender System Based on Space-Time Similarities |
Résumé:
The Internet of Things (IoT) concept promises a world of networked and interconnected devices that provides relevant content to users. Recommender systems can find relevant content for users in IoT environments, offering a user-adapted personalized experience. Collaboration-based recommenders in IoT environments rely on user-to-object, space-time interaction patterns. This extension of that idea takes into account user location and interaction time to recommend scattered, pervasive context-embedded networked objects. The authors compare their proposed system to memory-based collaborative methods in which user similarity is based on the ratings of previously rated items. Their proof-of-concept implementation was used in a real-world scenario involving 15 students interacting with 75 objects at Carlos III University of Madrid. |
| Auteurs: Munoz-Organero, Mario;Ramíez-González, Gustavo A.;Munoz-Merino, Pedro J.;Delgado Kloos, Carlos; |
| Apparue dans: IEEE Pervasive Computing |
| Date publication: 07.-2010, volume: 9, issue:3, pages: 81 - 87 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Combinatorial Approach to X-Tolerant Compaction Circuits |
Résumé:
Test response compaction for integrated circuits (ICs) with scan-based design-for-testability (DFT) support in the presence of unknown logic values (Xs) is investigated from a combinatorial viewpoint. The theoretical foundations of X-codes, employed in an X-tolerant compaction technique called X-compact, are examined. Through the formulation of a combinatorial model of X-compact, novel design techniques are developed for X-codes to detect a specified maximum number of errors in the presence of a specified maximum number of unknown logic values, while requiring only small fan-out. The special class of X-codes that results leads to an avoidance problem for configurations in combinatorial designs. General design methods and nonconstructive existence theorems to estimate the compaction ratio of an optimal X-compactor are also derived. |
| Auteurs: Fujiwara, Y.;Colbourn, C. J.; |
| Apparue dans: IEEE Transactions on Information Theory |
| Date publication: 07.-2010, volume: 56, issue:7, pages: 3196 - 3206 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Combinatorial Solution for Model-Based Image Segmentation and Real-Time Tracking |
Résumé:
We propose a combinatorial solution to determine the optimal elastic matching of a deformable template to an image. The central idea is to cast the optimal matching of each template point to a corresponding image pixel as a problem of finding a minimum cost cyclic path in the three-dimensional product space spanned by the template and the input image. We introduce a cost functional associated with each cycle, which consists of three terms: a data fidelity term favoring strong intensity gradients, a shape consistency term favoring similarity of tangent angles of corresponding points, and an elastic penalty for stretching or shrinking. The functional is normalized with respect to the total length to avoid a bias toward shorter curves. Optimization is performed by Lawler's Minimum Ratio Cycle algorithm parallelized on state-of-the-art graphics cards. The algorithm provides the optimal segmentation and point correspondence between template and segmented curve in computation times that are essentially linear in the number of pixels. To the best of our knowledge, this is the only existing globally optimal algorithm for real-time tracking of deformable shapes. |
| Auteurs: Schoenemann, Thomas;Cremers, Daniel; |
| Apparue dans: IEEE Transactions on Pattern Analysis and Machine Intelligence |
| Date publication: 07.-2010, volume: 32, issue:7, pages: 1153 - 1164 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Compact 100-PPS High-Voltage Trigger Pulse Generator |
Résumé:
Innovative design of a compact 100-pulses-per-second high-voltage trigger pulse generator, based on an incorporated structure with a curled parallel-plate capacitor and a spiral-strip pulse transformer, is presented. The repetitive trigger pulse generator was developed to trigger a trigatron, which has been used to pulse a 500-kV intense electron beam accelerator (IEBA). The trigger pulse generator consists of a spiral-strip transformer, a curled parallel-plate capacitor, two sharpening spark gaps, a repetitive controlling module, and a charging module. The generator system was designed based on the circuit theory and the electromagnetic theory. Experimental results show that the trigger pulse generator can deliver a 100-kV pulse with 80-ns rise time and 200-ns duration of full-width at half-maximum at a maximum repetition rate of 100 Hz. Due to its good stability, compact structure, and low cost, the high-voltage trigger pulse generator is an excellent candidate to trigger the IEBA system. |
| Auteurs: Liu, J.;Zhang, Y.;Chen, Z.;Feng, J.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1680 - 1686 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A compact butler matrix for WLAN application |
Résumé:
In this article, a compact butler matrix for wireless communications is designed and implemented at 2.4 GHz using defected ground structures (DGS).The butler matrix consists of a 3-dB coupler, crossover (0-dB coupler), and phase shifter. The 3-dB coupler and crossover are compacted using T-model of transmission line and DGS. The size of proposed butler matrix is about 35% of a conventional matrix. To verify simulation results, designed matrix has been implanted and measured. Fortunately, there is very good agreement between simulation results and measured results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2294-2298, 2010; DOI 10.1002/mop.25474 |
| Auteurs: Mohsen Maddah-Ali, Keyvan Forooraghi |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Compact Parallel-Plane Perpendicular-Current Feed for a Modified Equiangular Spiral Antenna |
Résumé:
The design and measurement is described of a compact (59.94 mm × 59.94 mm × 1.14 mm) bidirectional ultrawideband modified equiangular spiral antenna with an integrated feed internally matched to a 50-Ohm microstrip transmission line. An ultrawideband transition from microstrip to parallel-strip line soldered to a short (1.14 mm) twin-line transmission line feeds the spiral. The currents on the feed travel in a direction approximately perpendicular to the direction of the currents on the spiral at the points where the feed passes the spiral in close proximity (0.57 mm). Holes were etched from the metal arms of the spiral to reduce the impedance mismatch caused by coupling between the transmission line feed and the spiral. Measured and simulated radiation patterns and VSWR plots show good performance over the ultrawideband range (3.1-10.6 GHz) with a 2:1 VSWR everywhere in this range except for 3.33-3.95 GHz, which has a 3:1 VSWR. This spiral exhibits an elliptical polarization over the ultrawideband range. |
| Auteurs: Eubanks, T.W.;Kai Chang; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2193 - 2202 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A compact pentagonal monopole antenna for portable UWB systems |
Résumé:
Design of a compact microstrip-fed ultra-wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni-directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 × 30 mm2 on FR4 substrate with permittivity 4.4. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2390-2393, 2010; DOI 10.1002/mop.25449 |
| Auteurs: Paulbert Thomas, M. Gopikrishna, C. K. Aanandan, P. Mohanan, K. Vasudevan |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Compact Printed Antenna With an Embedded Double-Tuned Metamaterial Matching Network |
Résumé:
A compact antenna intended for use in a laptop computer is proposed with the antenna consisting of a simple radiating strip and a matching network based on a metamaterial particle. The matching network is used to increase the -10 dB bandwidth of the antenna. Double-tuned matching network theory is used to increase the bandwidth of the antenna by forming a loop on the Smith Chart inside a given VSWR circle. The matching network is implemented using a complementary-split-ring-resonator (CSRR) microstrip network to act as a shunt LC network. This is confirmed by means of a circuit model to model the CSRR-microstrip network. Finally the antenna is fabricated and tested with the measured and simulated results showing good agreement. The measured antenna has 560 MHz of bandwidth centered at 2.54 GHz with an efficiency of 89%. |
| Auteurs: Selvanayagam, M.;Eleftheriades, G.V.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2354 - 2361 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Compact Repetitive Unipolar Nanosecond-Pulse Generator for Dielectric Barrier Discharge Application |
Résumé:
Dielectric barrier discharge excitated by pulsed power is a promising approach for producing nonthermal plasma at atmospheric pressure, but pulsed power generators vary widely in performance and should be chosen according to application requirements. In this paper, a repetitive unipolar nanosecond-pulse generator is constructed using resonant charging and one-stage magnetic compression circuits, where IGBT and magnetic switches are the key units, respectively. The generator is capable of providing repetitive pulses with a voltage of up to 30 kV and duration of 70 ns at a 300 resistive load. Output pulse voltage can be adjusted by varying ac input voltage or trigger pulse-width. This compact and convenient generator has been used successfully to produce stable dielectric barrier discharge. |
| Auteurs: Tao Shao;Dongdong Zhang;Yang Yu;Cheng Zhang;Jue Wang;Ping Yan;Yuanxiang Zhou; |
| Apparue dans: IEEE Transactions on Plasma Science |
| Date publication: 07.-2010, volume: 38, issue:7, pages: 1651 - 1655 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Compact Wideband Leaky-Wave Antenna With Etched Slot Elements and Tapered Structure |
Résumé:
A compact wideband leaky-wave antenna (LWA) with etched slot elements and tapered structure is studied. The proposed antenna is composed of an asymmetric-fed multi-section tapered short leaky-wave antenna with two embedded slots and a ground plane with etched slot elements. Base on the concept of LWA, the asymmetric-fed is utilized to excite the first higher order mode. By etching slot elements on the ground plane, the current distribution of this antenna can be influenced to compact the width of conventional LWA. In order to achieve the impedance matching, this multi-section tapered short leaky-wave antenna is embedded with two rectangular slots. This technique not only improves the impedance matching but also suppresses the back lobe. According to the measured results, the impedance bandwidth achieves about 1.30 GHz for 7-dB return loss, which covers the range from 3.30 to 4.60 GHz, and the scanning angle of the measured main beam is about 36°, which covers the range from 17° to 53°. This short LWA is only about 1.14 λ0 at 3.4 GHz, and the back lobe can be suppressed by 7.5 dB at 4.3 GHz. Due to the etched slot elements on the ground plane, the frequency of the radiation angle is shifted to lower frequency by 750 MHz, which can compact the width of LWA by more than 20%. |
| Auteurs: Jin-Wei Wu;Jou, C.F.;Chien-Jen Wang; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2176 - 2183 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A comparative analysis and design of quantum-dot cellular automata memory cell architecture |
Résumé:
Quantum-dot cellular automata (QCA) nanotechnology is considered as the best candidate for memory system owing to its dense packages and low power consumption. This paper analyzes the drawbacks of the previous QCA memory architectures and improves memory cell that exploits regular clock zone layout by employing two new clocking signals and a compact Read/Write circuit. The proposed layout is verified with the modified QCADesigner simulator and is analyzed by considering the noise effect. This design, occupying only a fraction of the area compared with the previous memory design, has superior performance. It is shown that the clock circuitry is very regular, helping manufacturability for physical implementation. Comparisons show that Read/Write latency of the proposed design is mitigated, the overall cell number, control cell and layout area are reduced (100%), and its performance against random charge noise is presented to be better. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Xiaokuo Yang, Li Cai, Hongtu Huang, Xiaohui Zhao |
| Apparue dans: International Journal of Circuit Theory and Applications |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Comparative Study of Calderón Preconditioners for PMCHWT Equations |
Résumé:
The Calderón identities are used to precondition the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) equations for wave scattering by dielectric objects. Based on the Calderón identities, several versions of preconditioners are presented and studied. The memory requirements and computational costs of different preconditioners are analyzed and discussed. The convergence properties of the iterative solutions and the solution accuracy of the Calderón preconditioned PMCHWT equations are also investigated and compared theoretically and numerically at different frequencies. With the help of the Calderón preconditioners, the convergence rate of the iterative solutions of the PMCHWT equations is significantly improved. Several numerical examples are given to show the performance of the Calderón preconditioners and to draw some conclusions. |
| Auteurs: Su Yan;Jian-Ming Jin;Zaiping Nie; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2375 - 2383 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A comparative study of self-heating effect of nMOSFETs fabricated on SGOI and SGSOAN substrates |
Résumé:
In this work, for the first time, the electrical and thermal characteristics of strained Si/SiGe nanoscale n type metal-oxide-silicon field-effect transistors (MOSFETs) with silicon-on-aluminum nitride (SOAN) substrate are investigated by ISE TCAD. This novel structure is named as SGSOAN nMOSFET. A comparative study of self-heating effect (SHE) of nMOSFETs fabricated on SGOI and SGSOAN are presented in this paper. Numerical study results show that this novel SGSOAN structure can greatly eliminate excessive self-heating in devices, which gives a more promising application for SGOI to work at high temperature. |
| Auteurs: Hongxia, Liu , Bin, Li , Jin, Li , Bo, Yuan |
| Apparue dans: Microelectronics Reliability |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A comparison between LQR control for a long string of SISO systems and LQR control of the infinite spatially invariant version? |
Résumé:
In this paper we consider a long string of SISO systems which in the limit becomes a scalar infinite spatially invariant system. We compare the LQR control for long-but-finite strings with the LQR control for the corresponding infinite strings. We give analytical and numerical examples where these are quite different and we investigate the cause. In addition, we obtain sufficient conditions for the LQR solutions to be similar as the length of the string increases. |
| Auteurs: Ruth, Curtain , Orest, Iftime , Hans, Zwart |
| Apparue dans: Automatica |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Comparison of Two-Phase Computational Fluid Dynamics Codes Applied to the ITER First Wall Hypervapotron |
Résumé:
Enhanced radial transport in the plasma and the effect of ELMS may increase the ITER first wall heat loads to as much as 4 to 5 $hbox{MW/m}^{2}$ over localized areas. One proposed heatsink that can handle these higher loads is a CuCrZr hypervapotron. One concept for a first wall panel consists of 20 hypervapotron channels, each measuring 1400 mm long and 48.5 mm wide. The nominal cooling conditions anticipated for each channel are 400 g/s of water at 3 MPa and 100 $^{circ} hbox{C}$. This will result in boiling over a portion of the total length. A two-phase thermalhydraulic analysis is required to predict accurately the thermal performance. Existing heat transfer correlations used for nucleate boiling are not appropriate here because the flow does not reach fully developed conditions in the multi-segmented channels. Our design-by-analysis approach used two commercial codes, Fluent and Star-CCM+, to perform computational fluid dynamics analyses with conjugate heat transfer. Both codes use the Rensselear (RPI) model for wall heat flux partitioning to model nucleate boiling as implemented in user-defined functions. We present a comparison between the two codes for this Eulerian multiphase problem that relies on temperature dependent materials properties. The analyses optimized the hypervapotron geometry, including teeth height and pitch, as well as the depth of the back channel to permit highly effective boiling heat transfer in the grooves between the teeth while ensuring that no boiling could occur at the back channel exit. The analysis used a representative heat flux profile with the peak heat flux of 5 $hbox{MW/m}^{2}$ limited to a 50 mm length. The maximum surface temperature of the heatsink is 415 $^{circ}hbox{C}-
-
$. The baseline design uses 2 mm for the teeth height, a 3 mm width and 6 mm pitch, and a back channel depth of 8 mm. The teeth are detached from the sidewall by a 2-mm-wide slot on both sides that aids in sweep-out and quenching of the vapor bubbles. |
| Auteurs: Youchison, D. L.;Ulrickson, M. A.;Bullock, J. H.; |
| Apparue dans: IEEE Transactions on Plasma Science |
| Date publication: 07.-2010, volume: 38, issue:7, pages: 1704 - 1708 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A comparison study on the dynamics of planar 3-DOF 4-RRR, 3-RRR and 2-RRR parallel manipulators |
Résumé:
This paper presents a comparison study on the dynamics of three planar 3-DOF parallel manipulators, one with 3-RRR structure, and the other two with 2-RRR and 4-RRR structures. The inverse kinematics and Jacobian matrix of these mechanisms are analyzed. The dynamic formulations in the linear form are derived and a dynamic performance index is given to compare their dynamic performances. The results show that the 2-RRR parallel manipulator has the worst dynamic performance. |
| Auteurs: Jun, Wu , Jinsong, Wang , Zheng, You |
| Apparue dans: Robotics and Computer-Integrated Manufacturing |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Complete Description of the QoS Feasibility Region in the Vector Broadcast Channel |
Résumé:
We characterize the complete quality-of-service (QoS) feasibility region and present a simple feasibility test for given QoS requirements in the Gaussian vector broadcast channel. While most contributions in the literature recast the QoS constraints into requirements for the signal-to-interference-and-noise ratios (SINRs), we convert them into upper bounds for the minimum mean square errors (MMSEs) instead and test feasibility in the MMSE domain. Our main contribution is a complete description of the feasible MMSE region. Its closure is shown to be a polytope and we find the complete set of its bounding half-spaces noniteratively after a finite number of steps. The polytope can easily be converted into any other QoS domain like SINR or rate. However, the simple geometry of the MMSE domain is lost in other domains. Once the bounding half-spaces are determined, any target MMSE tuple can quickly be checked for feasibility by verifying its membership to the interior of the polytope. For nondegenerate channels, the only relevant bounding half-space is essentially the lower bound on the sum mean square error. No further computations are necessary contrary to existing feasibility checks which iteratively solve eigenproblems in an alternating optimization framework for every single QoS requirement to test. For two particular user/antenna configurations, we find a noniterative closed form solution for the optimum power allocation of the signal-to-interference ratio (SIR) balancing. |
| Auteurs: Hunger, R.;Joham, M.; |
| Apparue dans: IEEE Transactions on Signal Processing |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 3870 - 3878 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Computer-Aided Diagnosis System of Nuclear Cataract |
Résumé:
Cataracts are the leading cause of blindness worldwide, and nuclear cataract is the most common form of cataract. An algorithm for automatic diagnosis of nuclear cataract is investigated in this paper. Nuclear cataract is graded according to the severity of opacity using slit lamp lens images. Anatomical structure in the lens image is detected using a modified active shape model. On the basis of the anatomical landmark, local features are extracted according to clinical grading protocol. Support vector machine regression is employed for grade prediction. This is the first time that the nucleus region can be detected automatically in slit lamp images. The system is validated using clinical images and clinical ground truth on >5000 images. The success rate of structure detection is 95% and the average grading difference is 0.36 on a 5.0 scale. The automatic diagnosis system can improve the grading objectivity and potentially be used in clinics and population studies to save the workload of ophthalmologists. |
| Auteurs: Li, H.;Lim, J.;Liu, J.;Mitchell, P.;Tan, A.;Wang, J.;Wong, T.; |
| Apparue dans: IEEE Transactions on Biomedical Engineering |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1690 - 1698 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A constraint programming approach to tool allocation and production scheduling in flexible manufacturing systems |
Résumé:
This paper presents a constraint programming (CP) methodology to deal with the scheduling of flexible manufacturing systems (FMSs). The proposed approach, which consists of both a model and a search strategy, handles several features found in industrial environments, such as limitations on number of tools in the system, lifetime of tools, as well as tool magazine capacity of machines. In addition, it tackles the problem in a integrated way by considering tool planning and allocation, machine assignment, part routing, and task timing decisions altogether in the approach. The formulation, which is able to take into account a variety of objective... |
| Auteurs: L.J., Zeballos |
| Apparue dans: Robotics and Computer-Integrated Manufacturing |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Context-Sensitive Technique Robust to Registration Noise for Change Detection in VHR Multispectral Images |
Résumé:
This paper presents an automatic context-sensitive technique robust to registration noise (RN) for change detection (CD) in multitemporal very high geometrical resolution (VHR) remote sensing images. Exploiting the properties of RN in VHR images, the proposed technique analyzes the distribution of the spectral change vectors (SCVs) computed according to the change vector analysis (CVA) in a quantized polar domain. The method studies the SCVs falling into each quantization cell at different resolution levels (scales) to automatically identify the effects of RN in the polar domain. This information is jointly exploited with the spatial context information contained in the neighborhood of each pixel for generating the final CD map. The spatial context information is modeled through the definition of adaptive regions homogeneous both in spatial and temporal domain (parcels). Experimental results obtained on real VHR remote sensing multitemporal images confirm the effectiveness of the proposed technique. |
| Auteurs: Marchesi, S.;Bovolo, F.;Bruzzone, L.; |
| Apparue dans: IEEE Transactions on Image Processing |
| Date publication: 07.-2010, volume: 19, issue:7, pages: 1877 - 1889 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Control Scheme With Energy Saving and DC-Link Overvoltage Rejection for Induction Motor Drives of Electric Vehicles |
Résumé:
This paper presents a control scheme for an induction motor that integrates, within a coherent solution, some of the features that are commonly required from an electric vehicle drive. The main features of the proposed control scheme are the capability to exploit the maximum torque in the whole speed range, a weak dependence on the motor parameters, a good robustness against the variations of the dc-link voltage, and, whenever possible, the maximum efficiency. The performance of the control scheme is verified by experimental tests. |
| Auteurs: Casadei, D.;Mengoni, M.;Serra, G.;Tani, A.;Zarri, L.; |
| Apparue dans: IEEE Transactions on Industry Applications |
| Date publication: 07.-2010, volume: 46, issue:4, pages: 1436 - 1446 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Control Strategy for Hybrid Power Filter to Compensate Four-Wires Three-Phase Systems |
Résumé:
A control algorithm is proposed for a three-phase hybrid power filter constituted by a series active filter and a shunt passive filter. The control strategy is based on the dual formulation of the compensation system principles. It is applied by considering a balanced and resistive load as ideal load, so that the voltage waveform injected by the active filter is able to compensate the reactive power, to eliminate harmonics of the load current and to balance asymmetrical loads. This strategy improves the passive filter compensation characteristics without depending on the system impedance, and avoiding the series/shunt resonance problems, since the set load-filter would present resistive behavior. An experimental prototype was developed and experimental results are presented. |
| Auteurs: Salmerón, P.;Litrán, S. P.; |
| Apparue dans: IEEE Transactions on Power Electronics |
| Date publication: 07.-2010, volume: 25, issue:7, pages: 1923 - 1931 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A convexity-based homotopy method for nonlinear optimization in model predictive control |
Résumé:
This paper presents a convexity-based homotopy solution procedure to non-convex optimal control problems (OCPs) arising in model predictive control. The approach deals with a special class of OCP formulations, where the dynamic system involved is control-affine and the objective is a penalty on deviations from a state reference trajectory. The non-convex OCP is modified by introducing a penalized pseudo state and a homotopy parameter which gradually transforms the original problem into a convex one. The method solves first this convex formulation and uses the result to initialize the solution of the next problem on the zero path, recovering the original OCP. The proposed methodology is evaluated for the benchmark control problem of an isothermal chemical reactor with Van de Vusse reactions and input multiplicity. For the simple case with control horizon one, the method is able to find the global solution due to the convex initialization, while local optimization techniques only lead to a local minimum. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Julián Bonilla, Moritz Diehl, Filip Logist, Bart De Moor, Jan F. M. Van Impe |
| Apparue dans: Optimal Control Applications and Methods |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Cooperative Multicast Strategy in Wireless Networks |
Résumé:
Multicast is a bandwidth-efficient mechanism to provide wireless services for a group of terminals. Providing reliable wireless multicast is challenging due to packet loss and channel fading. In this research, we investigate the medium-access-control (MAC) layer cooperation to enhance the reliability of wireless multicast. We show that the optimal relaying strategy is a pure threshold policy, i.e., the optimal number of relays is bounded by a threshold. We also propose a simple and efficient algorithm to find the optimal time allocation for the direct and relay transmissions. |
| Auteurs: Niu, B.;Jiang, H.;Zhao, H. V.; |
| Apparue dans: IEEE Transactions on Vehicular Technology |
| Date publication: 07.-2010, volume: 59, issue:6, pages: 3136 - 3143 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Critical Cross-Examination on Load-Balancing Transformers for Distribution Systems |
Résumé:
A load balancing transformer (LBT) has already been suggested for improving the unbalance of three-phase primary currents. Each phase includes one extra pair of coupling windings in addition to the usual primary and secondary windings. Two coupling windings, located on two different phases, are made in series, where the resulting circuit is then reversely paralleled with the secondary winding placed on the third phase. Under unbalanced conditions, the load currents are distributed between the coupling and secondary windings that are supplied through different primary phases. This paper proposes a method in order to define all possible LBTs, which paves the way to cross-examine and select the best connections of windings for the LBT. Starting from the original LBT, it is shown that the best LBT is practically connected, such as a zig-zag winding. Then, a novel idea is suggested in which a controller and some four-quadrant semiconductor switches contribute to the improvement of the performance of the LBT. These switches should control the amount of current transfer from one phase to another. A combinatorial selection problem is arranged to find the best way of switching modulation. Both simulations and experimental works (using a designed 12-kVA laboratory prototype) verify the studied examination and proposals, showing the switch-mode zig-zag LBT as having the best performance. |
| Auteurs: Ahmadi, D.;Bina, M. T.;Golkar, M. A.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1645 - 1656 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Cross-Layer Approach-Based Gnutella for Collaborative Virtual Environments over Mobile Ad Hoc Networks |
Résumé:
Collaborative Virtual Environments (CVEs) such as military training programs, emergency preparedness simulations, and online games place strict requirements on network performance when participating users share the 3D virtual environment through their mobile devices in an ad hoc network. However, most support systems for existing CVEs are confined to a desktop setting, thus preventing collaboration while users are mobile. In this work, we propose and evaluate a Gnutella peer-to-peer network over mobile ad hoc networks (MANETs) to support Mobile Collaborative Virtual Environment (MCVE) applications. Both architectures share some common features such as decentralization, self-reorganization, and self-healing. However, peer-to-peer networks and MANETs operate on different network layers, and thus, cause poor performance. To address this problem, we explore a novel cross-layer approach to improve the overall performance of CVEs over MANETs. The network layer should be aware of the user's physical position in the virtual environment (VE) in order to minimize network traffic and cope with a moderate workload between nodes. In this paper, we present a cross-layer approach model for collaborative virtual environment over MANET. We describe its implementation and evaluate its performance using NS2 simulator. |
| Auteurs: Boukerche, A.;Zarrad, A.;Araujo, R.B.; |
| Apparue dans: IEEE Transactions on Parallel and Distributed Systems |
| Date publication: 07.-2010, volume: 21, issue:7, pages: 911 - 924 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Cusum-Based Multilevel Alerting Method for Physiological Monitoring |
Résumé:
Alerting systems used by current physiological monitors are designed to detect changes in the levels of vital signs, but they tend to be very sensitive to artifacts. This paper proposes a method to detect changes in the direction of trend and generate multilevel alerts according to the statistical significance of the detection. One-point-ahead signal predictions are calculated by averaging the historical data with the weights decreasing in the past. The two-sided cumulative sums (Cusum) of the prediction errors are tested against multiple thresholds to detect change points with two levels of certainty. The temporal shapes of the detected changes are analyzed using heuristics to determine whether to trigger an alert. The method was tested offline using 20 cases collected during surgery at a local hospital. The detection results were evaluated by two experienced anesthesiologists. The direction of trend was correctly detected in $90.2%$ of the annotated changes for end-tidal carbon dioxide, $89.4%$ for expiratory minute volume, $91.8%$ for peak airway pressure, and $95.4%$ for noninvasive blood pressure. The certainty levels of the true-positive alerts estimated by the algorithm have a high ratio of agreement with the anesthesiologists’ evaluations. |
| Auteurs: Yang, P.;Dumont, G.;Ansermino, J. M.; |
| Apparue dans: IEEE Transactions on Information Technology in Biomedicine |
| Date publication: 07.-2010, volume: 14, issue:4, pages: 1046 - 1052 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Data Capturing Method for Buses on Chip |
Résumé:
In this paper, a new data reading technique for a bus of lines is proposed for fast operation. The proposed method utilizes multiple reference voltages available within a line's receiving logic and the initial conditions of wires in order to determine early and accurately the transmitted data of the current cycle. The presented technique does not require repeater insertion for reasonably long lines and it can significantly accelerate signal propagation. Experimental results are given in the 65 nm CMOS process for interconnects of various lengths. |
| Auteurs: Skoufis, M. N.;Karmarkar, K.;Tragoudas, S.;Haniotakis, T.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1631 - 1641 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A delta-method technique in the wavelet domain to determine statistical quantities of the response of electromagnetic devices with uncertain parameters |
Résumé:
In this paper a method to determine the mean value and the variance of the response of a system with uncertain parameters is proposed. With the term 'response of a system' we indicate either the value of a single parameter that represents a figure of merit of a device (e.g. the efficiency of a transmission system or the band width of a communication channel) or a characteristic function of the system (e.g. the impulse or the frequency response). In the latter case we estimate the mean value and the variance at every sample of the response. The estimate is performed by using the delta method, a technique for approximating expected values of functions of random variables when the direct evaluation is not feasible. Two examples of the application of the proposed procedure are reported and the results are compared with simulations performed by a Monte Carlo analysis. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Sami Barmada, Antonino Musolino, Marco Raugi, Mauro Tucci |
| Apparue dans: International Journal of Numerical Modelling: Electronic Networks, Devices and Fields |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A differential quadrature analysis of dynamic and quasi-static magneto-thermo-elastic stresses in a conducting rectangular plate subjected to an arbitrary variation of magnetic field |
Résumé:
A rapid, convergent and accurate differential quadrature method (DQM) is employed for numerical simulation of dynamic and quasi-static magneto-thermo-elastic stresses in a conducting rectangular plate subjected to an arbitrary variation of magnetic field. Fundamental equations of plane electromagnetic, temperature and elastic fields are formulated. To the best of the authors' knowledge, this is the first attempt to apply the DQM to magneto-thermo-elasticity and the first attempt to analyze a finite two-dimensional magneto-thermo-elastic problem. The fundamental equations and the inhomogeneous time-dependent boundary conditions are discretized in spatial and temporal domain by differential quadrature (DQ) rules. The unknowns satisfying the governing equations,... |
| Auteurs: Yufeng, Xing , Bo, Liu |
| Apparue dans: International Journal of Engineering Science |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Digitally Controlled Unity Power Factor Compensator for Pulse-Burst-Modulated Loads |
Résumé:
Pulse-burst-modulated (PBM) loads cause line losses that are significant when compared with equivalent loads that are compensated to operate with sinusoidal line currents. This study details the conceptual design of a system meant to compensate the power factor of a load power conditioned by means of PBM. The compensator controller is a digital controller that monitors the line current and voltage and adjusts the compensation current accordingly. Simulations of the proposed method confirm the effectiveness of such a compensator maintaining a nearly sinusoidal line current, even in the presence of an inductive load. |
| Auteurs: Ferreira, K. J.;Emanuel, A. E.; |
| Apparue dans: IEEE Transactions on Power Electronics |
| Date publication: 07.-2010, volume: 25, issue:7, pages: 1888 - 1893 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Direct Approach for the Frequency-Adaptive Feedforward Cancellation of Harmonic Disturbances |
Résumé:
This paper is concerned with the robust rejection of harmonic disturbances with unknown frequency and amplitude affecting uncertain linear system. The developed control scheme combines the properties of adaptive feedforward cancellation (AFC) techniques with the phase and frequency detection capabilities provided by a nonlinear frequency estimation algorithm. Under mild assumptions on the nominal model of the system to be controlled, the proposed scheme is proven to achieve the complete rejection of harmonic disturbances at the input or at the output of the system. A detailed stability analysis based on averaging provides useful informations on the effect of the tuning parameters over the convergence of the estimator. The effectiveness of the proposed approach is demonstrated by a two-time scale averaging analysis. |
| Auteurs: Pin, G.; |
| Apparue dans: IEEE Transactions on Signal Processing |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 3523 - 3530 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A direct method for porous particle density characterization applied to activated carbons |
Résumé:
A new method for setting the porous particle overall density is proposed. The apparent density of the particle including the solid matter as well as the different internal porosities (from microporous to macroporous pore size ranges) is currently needed for industrial applications as gas storage, heterogeneous catalysis... The technique proposed is based on the principle own immersion fluid applied to a granular medium consisting of extremely fine particles playing the role of non-wetting liquid. Here are presented the restrictive theoretical and experimental conditions, which have to be fulfilled by any granular medium before applying this principle. The conventional technique of... |
| Auteurs: G., Plantard , V., Goetz , X., Py |
| Apparue dans: Advanced Powder Technology |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Discrete-Time Neural Network for Optimization Problems With Hybrid Constraints |
Résumé:
Recurrent neural networks have become a prominent tool for optimizations including linear or nonlinear variational inequalities and programming, due to its regular mathematical properties and well-defined parallel structure. This brief presents a general discrete-time recurrent network for linear variational inequalities and related optimization problems with hybrid constraints. In contrary to the existing discrete-time networks, this general model can operate not only on bound constraints, but also on hybrid constraints comprised of inequality, equality and bound constraints. The model has dynamical properties of global convergence, asymptotical and exponential convergences under some weaker conditions. Numerical examples demonstrate its efficacy and performance. |
| Auteurs: Huajin Tang;Haizhou Li;Zhang Yi; |
| Apparue dans: IEEE Transactions on Neural Networks |
| Date publication: 07.-2010, volume: 21, issue:7, pages: 1184 - 1189 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A disposable piezoelectric micropump with high performance for closed-loop insulin therapy system |
Résumé:
This paper presents a novel and disposable piezoelectric micropump with high performance for a new closed-loop insulin therapy system. The micropump was designed by using four chambers in a serial connection structure, and was manufactured by using the materials with good bio-compatibility. The major advantages of the proposed micropump include: possessing high performance under lower working voltage, low cost, high resolution of flow rate. A maximum backpressure of 22 kPa was recorded at an applied voltage of 36Vpp and a driving frequency of 200Hz, the maximum resolution of outflow can obtain 6.23×10-5ml per pulse. Through in vivo animal tests, the... |
| Auteurs: Guojun, Liu , Chuanliang, Shen , Zhigang, Yang , Xinxia, Cai , Honghai, Zhang |
| Apparue dans: Sensors and Actuators A: Physical |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Distortion-Compensated Charge Transfer Amplifier for a 1.66-MHz Cyclic Pipeline ADC |
Résumé:
A distortion-compensated charge transfer amplifier (DCCTA) is proposed to improve the linearity constraints of the differential charge transfer amplifier (DCTA). The proposed DCCTA effectively reduces distortion at its output by source degeneration, cross coupling, and making the drain-to-source voltage of the amplifying transistor independent of the applied input signal. This DCCTA yields an effective number of bits of 9.26 bits, compared with 6.05 bits for the DCTA at 40 MHz while consuming only 13.5 $muhbox{W}$ from a 1.2-V source. A 1.66-MHz cyclic pipeline analog-to-digital converter employing this DCCTA as a residue amplifier was simulated using 90-nm CMOS process, resulting in a peak resolution of 9.21 bits, without being limited by the thermal noise. |
| Auteurs: Sandhu, T. S.;El-Sankary, K.;El-Masry, E.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 507 - 511 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Distributed Contention Vector Division Multiple Access (D-CVDMA) Protocol for Wireless Networks |
Résumé:
Traditional Time Division Multiple Access (TDMA) protocol provides deterministic periodic collision-free data transmissions. However, TDMA lacks flexibility and exhibits low efficiency in dynamic environments such as wireless LANs. On the other hand, contention-based MAC protocols such as the IEEE 802.11 DCF are adaptive to network dynamics but are generally inefficient in heavily loaded or large networks. To take advantage of the both types of protocols, a D-CVDMA protocol is proposed. It is based on the k-round elimination contention (k-EC) scheme, which provides fast contention resolution for Wireless LANs. D--CVDMA uses a contention mechanism to achieve TDMA-like collision-free data transmissions, which does not need to reserve time slots for forthcoming transmissions. These features make the D-CVDMA robust and adaptive to network dynamics such as node leaving and joining, changes in packet size and arrival rate, which, in turn, make it suitable for the delivery of hybrid traffic including multimedia and data content. D-CVDMA is designed for single-hop wireless ad hoc networks. Analyses and simulations demonstrate that D-CVDMA outperforms the IEEE 802.11 DCF and k-EC in terms of network throughput, delay, jitter, and fairness. |
| Auteurs: Bosheng Zhou;Marshall, A.; |
| Apparue dans: IEEE Transactions on Mobile Computing |
| Date publication: 07.-2010, volume: 9, issue:7, pages: 1049 - 1054 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Dynamic Region-of-Interest Vision Tracking System Applied to the Real-Time Wing Kinematic Analysis of Tethered Drosophila |
Résumé:
Tracking objects that move fast with respect to their size is challenging because it necessitates large field of views often incompatible with the required spatial and temporal resolutions. Here, we present a novel computer vision system that overcomes this tradeoff by employing a camera with dynamic region-of-interest (ROI) capabilities, combined with an efficient predictive approach. We apply this method to extract the wing kinematics of tethered flying fruit flies in real time. At each frame, only the pixels immediately surrounding the wing are exposed, and the wing position is extracted. It is then fed to an extended Kalman filter that extracts four key parameters of the measurement time-course and, therefore, provides real-time feedback of wing motion. Using this approach, we are able to sample the wing position of both wings at 7 kHz in a 2500 pixel ROI. Our methods promise new applications that can be implemented in general purpose digital hardware for high performance tracking and process control in a broad range of applications in technology and science. |
| Auteurs: Graetzel, C.F.;Nelson, B.J.;Fry, S.N.; |
| Apparue dans: IEEE Transactions on Automation Science and Engineering |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 463 - 473 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Dynamic Search Range Algorithm for Stabilized Reduction of Memory Traffic in Video Encoder |
Résumé:
Embedded compression is commonly employed in a video codec to reduce the data traffic to/from off-chip frame memory. We proposed a method for maintaining the memory bandwidth requirement at a significantly reduced level through dynamic search range adjustment for the motion estimation based on the observed relationship between the compression ratio and the motion vector. This, together with the so-called “center moving” to adjust the newly incoming macroblocks, helped significantly lower the requirement of the memory bandwidth without a fluctuation. Experimental results have shown that the memory bandwidth requirement can be finally stabilized to 20% of that of the full search. The image quality degradation was merely 0.02 dB. |
| Auteurs: Jung, J.;Kim, J.;Kyung, C.-M.; |
| Apparue dans: IEEE Transactions on Circuits and Systems for Video Technology |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 1041 - 1046 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Dynamic Subspace Method for Hyperspectral Image Classification |
Résumé:
Many studies have demonstrated that multiple classifier systems, such as the random subspace method (RSM), obtain more outstanding and robust results than a single classifier on extensive pattern recognition issues. In this paper, we propose a novel subspace selection mechanism, named the dynamic subspace method (DSM), to improve RSM on automatically determining dimensionality and selecting component dimensions for diverse subspaces. Two importance distributions are proposed to impose on the process of constructing ensemble classifiers. One is the distribution of subspace dimensionality, and the other is the distribution of band weights. Based on the two distributions, DSM becomes an automatic, dynamic, and adaptive ensemble. The real data experimental results show that the proposed DSM obtains sound performances than RSM, and that the classification maps remarkably produce fewer speckles. |
| Auteurs: Yang, J.-M.;Kuo, B.-C.;Yu, P.-T.;Chuang, C.-H.; |
| Apparue dans: IEEE Transactions on Geoscience and Remote Sensing |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 2840 - 2853 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Dynamical Games Approach to Transmission-Rate Adaptation in Multimedia WLAN |
Résumé:
This paper considers the scheduling, rate adaptation, and buffer management in a multiuser wireless local-area network (WLAN) where each user transmits scalable video payload. Based on opportunistic scheduling, users access the available medium (channel) in a decentralized manner. The rate adaptation problem of the WLAN multimedia networks is then formulated as a general-sum switching control dynamic Markovian game by modelling the video states and block fading channel qualities of each user as a finite states Markovian chain. A value iteration algorithm is proposed to compute the Nash equilibrium policy of such a game and the convergence of the algorithm is also proved. We also give assumptions on the system so that the Nash equilibrium transmission policy of each user is a randomization of two pure policies with each policy nondecreasing on the buffer state occupancy. Based on this structural result, we use the policy gradient algorithm to compute the Nash equilibrium policy. |
| Auteurs: Huang, J. W.;Mansour, H.;Krishnamurthy, V.; |
| Apparue dans: IEEE Transactions on Signal Processing |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 3635 - 3646 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A fast algorithm for the linear canonical transform |
Résumé:
In recent years there has been a renewed interest in finding fast algorithms to compute accurately the linear canonical transform (LCT) of a given function. This is driven by the large number of applications of the LCT in optics and signal processing. The well-known integral transforms: Fourier, fractional Fourier, bilateral Laplace and Fresnel transforms are special cases of the LCT. In this paper we obtain an O(N log N) algorithm to compute the LCT by using a chirp-FFT-chirp transformation yielded by a convergent quadrature formula for the fractional Fourier transform. This formula gives a unitary discrete LCT in closed form.... |
| Auteurs: Rafael G., Campos , Jared, Figueroa |
| Apparue dans: Signal Processing |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
» A Fast and High-Precision VCO Frequency Calibration Technique for Wideband  Fractional-N Frequency Synthesizers |
Résumé:
A VCO frequency calibration technique suitable for a wideband fractional-N PLL is presented. It provides a fast and high-precision search for an optimal discrete tuning curve of an $LC$ VCO during the coarse tuning process in a fractional-N PLL. A high-speed frequency error detector (FED) converts the VCO frequency to a digital value and computes the exact frequency difference from a target frequency. A minimum error code finder finds an optimal code that is closest to the target frequency. Due to the pure digital domain operation, a $Delta Sigma $ modulator in PLL can be deactivated during the calibration process, which makes this technique fast and accurate especially for a $Delta Sigma $ fractional-N PLL. We achieve a single-bit calibration time of only $kT_{REF}$ for obtaining a frequency resolution of $f_{REF}/k$, and compared to the conventional techniques, which is the best performance in terms of the calibration time versus resolution. Such fast VCO frequency calibration can greatly reduce the total lock time in a PLL. A 2.3–3.9 GHz fractional-N PLL employing the proposed calibration technique is implemented in 0.13 $~mu{hbox {m}}$ CMOS. Successful operation is verified through experimental results. The measured calibration time for a 6-bit capbank is 1.09 and 2.03$~mu{hbox {s}} $ for a frequency resolution of 19.2 and 4.8 MHz, respectively. |
| Auteurs: Shin, J.;Shin, H.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1573 - 1582 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Fault Diagnosis Method of Power Systems Based on Improved Objective Function and Genetic Algorithm-Tabu Search |
Résumé:
Based on the improved optimization objective function of fault diagnosis, a genetic algorithm-Tabu search (GATS) method is introduced for the purpose of fault diagnosis of power systems. The genetic algorithm has good global search ability, while the Tabu search algorithm has good local search ability. Integrating the advantages of these two algorithms, a new hybrid algorithm, called GATS, can be obtained. Using the function of Shcaffer, the advantages of GATS are proven in this paper. The results of case studies show that GATS is superior to conventional methods in terms of the sensitivity of original solution and the dependency of original parameters. The satisfactory results can be obtained when the GATS method is applied in the event of abnormal operations of protective relays and circuit breakers or the multiple-fault scenarios. |
| Auteurs: Lin, X.;Ke, S.;Li, Z.;Weng, H.;Han, X.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1268 - 1274 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A feasibility study of pressure-retarded osmosis power generation system based on measuring permeation volume using reverse osmosis membrane |
Résumé:
A pressure-retarded osmosis (PRO) power generation system is a hydroelectric power system which utilizes permeation flow through a semipermeable membrane. Permeation flow is generated by the potential energy of the salinity difference between sea water and fresh water. Since the cost of the membrane is high, the permeation performance of the membrane must be improved in order to realize PRO systems. We have investigated reverse osmosis (RO) membrane products as semipermeable membranes and measured the permeation volume of a few products. The generation power per unit membrane area calculated from the permeation volume is about 0.62 W/m2. But as a result of our improvements (greater salt water volume, spacers for fresh water channel with the function of discharging concentrated salinity, extralow-pressure type of membrane, washing the support layer of membrane when the generation power falls by half) the generated power may be 2.43 W/m2. Then the power system cost would be about 4.1 million yen/kW. In addition, if the support layer of the membrane is made thinner and a PRO system is applied to equipment where pumping power for another purpose is available (wastewater treatment plants located at the seaside, thermal and nuclear power plants, sea water desalination plants), the generated power may be increased. These improvements may enable PRO systems to be realized at a cost close to that of photovoltaic power systems. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 8-20, 2010; Published online in Wiley InterScience (). DOI 10.1002/eej.21000 |
| Auteurs: Hiroshi Enomoto, Masashi Fujitsuka, Tomoyasu Hasegawa, Masatoshi Kuwada, Akihiko Tanioka, Mie Minagawa |
| Apparue dans: Electrical Engineering in Japan |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A filter for a state space model with fractional Gaussian noise? |
Résumé:
A filter for estimating the hidden signal and parameters in a state space model, where the noise in the observations is fractional Gaussian noise, is obtained. |
| Auteurs: Robert J., Elliott , Jia, Deng |
| Apparue dans: Automatica |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Framework for RFID Deployment in Supply Chains |
Résumé:
The proposed framework shows how the granularity of tagging and deployment scope affect RFID implementation, helping managers identify RFID benefits and barriers and align deployment with their company's business strategy and return-on-investment goals. |
| Auteurs: Bradley, James;Guerrero, Hector; |
| Apparue dans: IT Professional |
| Date publication: 07.-2010, volume: 12, issue:4, pages: 44 - 50 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Frequency-Multiplied Source With More Than 1 mW of Power Across the 840–900-GHz Band |
Résumé:
We report on the design, fabrication, and characterization of an 840–900-GHz frequency multiplier chain that delivers more than 1 mW across the band at room temperature with a record peak power of 1.4 mW at 875 GHz. When cooled to 120 K, the chain delivers up to 2 mW at 882 GHz. The chain consists of a power amplifier module that drives two cascaded frequency triplers. This unprecedented output power from an electronic source is achieved by utilizing in-phase power-combining techniques. The first stage tripler uses four power-combined chips while the last stage tripler utilizes two power-combined chips. The source output was analyzed with a Fourrer transform spectrometer to verify signal purity. |
| Auteurs: Maestrini, A.;Ward, J. S.;Gill, J. J.;Lee, C.;Thomas, B.;Lin, R. H.;Chattopadhyay, G.;Mehdi, I.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1925 - 1932 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A fused system of sensing and communication with hetero-core spliced fiber optic sensors |
Résumé:
We have developed an optical fiber network combining communication and sensing using a hetero-core spliced fiber optic sensor inserted into an existing communication line. The measurement uses the Internet infrastructure effectively, and the sensitivity characteristic by wavelength of the measurement was examined. In addition, six binary switch modules and one displacement sensor module using the hetero-core spliced fiber optic sensor were inserted into an actual communication line, and the influence on the communication was examined. The hetero-core spliced fiber optic sensor showed the characteristic of loss only. When the sensor is inserted into the communication line, if the loss can be controlled to within tolerance to the wavelength of 1.31 [mu]m of the communication line, a measurement function can be added to the communication line by a comparatively simple construction method. In addition, we realized a multiple binary switch measurement in real-time basis with tandem connection by simple addressing algorithm. The binary switches can be applied to a home security system to monitor the state of doors opening and closing. We have successfully fabricated and demonstrated the binary switch sensing system in tandem connection consisting of three binary switches using the proposed method. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(3): 40-48, 2010; Published online in Wiley InterScience (). DOI 10.1002/ eej.21021 |
| Auteurs: Norihiko Shinomiya, Hiroyuki Sasaki, Michiko Nishiyama, Emiko Kondo, Yuko Ito, Kazuhiro Watanabe |
| Apparue dans: Electrical Engineering in Japan |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A fuzzy approach for multiple-receiver digital communication systems with data fusion |
Résumé:
Many multiple-receiver diversity schemes employ hard decisions combining rules to achieve a diversity gain in digital communications. In this paper, a fuzzy combining approach in diversity systems is proposed. The confidence levels associated with the local receiver soft-decisions are modeled by means of fuzzy membership functions. The reliabilities of the local receivers are weighted by the soft-decision confidence levels and fused in a central digital receiver to decide which symbol was transmitted. The performance of the proposed approach is evaluated and compared to the performance of optimal diversity, majority voting, optimal partial decision, and selection diversity in case of binary... |
| Auteurs: Ashraf M., Aziz |
| Apparue dans: AEU - International Journal of Electronics and Communications |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Fuzzy Rule-Based Approach for Islanding Detection in Distributed Generation |
Résumé:
The proposed method develops a fuzzy rule-based classifier that was tested using features for islanding detection in distributed generation. In the developed technique, the initial classification boundaries are found out by using the decision tree (DT). From the DT classification boundaries, the fuzzy membership functions (MFs) are developed and the corresponding rule base is formulated for islanding detection. But some of the fuzzy MFs are merged based upon similarity the measure for reducing the fuzzy MFs and simplifying the fuzzy rule base to make it more transparent. The developed fuzzy rule-based classifier is tested using features with noise up to a signal-to-noise ratio of 20 dB and provides classification results without misdetection, which shows the robustness of the proposed approach for islanding detection for distributed generations in the distribution network. |
| Auteurs: Samantaray, S. R.;El-Arroudi, K.;Joos, G.;Kamwa, I.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1427 - 1433 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Galois field-based logic synthesis with testability |
Résumé:
In deep-submicron very-large-scale integration (VLSI) systems, efficient circuit testability is one of the most demanding requirements. An automatic synthesis technique for designing efficiently testable logic circuits is one of the ways to tackle the problem. To this end, this study introduces the generalised theory and a new fast efficient graph-based decomposition technique for the functions over finite fields defined over the set GF(N), where N is a power of a prime number, which utilises the data structure of the multiple-output decision diagrams. In particular, the proposed technique can decompose any N valued arbitrary function over the fields conjunctively and disjunctively. The proposed technique is capable of generating testable circuits. The experimental results show that the proposed method is more economical in terms of literal count compared to the existing approaches. Furthermore, the authors have shown that the basic block can be tested with only eight test vectors. |
| Auteurs: Mathew, J.;Jabir, A.M.;Singh, A.K.;Rahaman, H.;Pradhan, D.K.; |
| Apparue dans: IET Computers & Digital Techniques |
| Date publication: 07.-2010, volume: 4, issue:4, pages: 263 - 273 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A General Model for Estimating the Laminated Steel Losses Under PWM Voltage Supply |
Résumé:
The new model is based on a modified Steinmetz equation and employs a hysteresis-loss multiplicative coefficient and a combined coefficient for eddy-current and excess losses, both coefficients being variable with induction and frequency. The material model coefficients are first identified through multifrequency tests with sine-wave excitation. The iron-loss increase due to pulsewidth-modulation supply is estimated using global waveform parameters of the nonsinusoidal voltage. The study includes three different grades of non-grain-oriented electric steel. The data cover a wide range of fundamental frequency from 10 to 600 Hz and induction from 0.05 to 2 T. The errors of the computational model are small at relatively low fundamental frequency and increase thereafter. The main advantages of the model are its simplicity of use and minimal data requirements. |
| Auteurs: Popescu, M.;Ionel, D. M.;Boglietti, A.;Cavagnino, A.;Cossar, C.;McGilp, M. I.; |
| Apparue dans: IEEE Transactions on Industry Applications |
| Date publication: 07.-2010, volume: 46, issue:4, pages: 1389 - 1396 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A General Upper Bound on the Size of Constant-Weight Conflict-Avoiding Codes |
Résumé:
Conflict-avoiding codes are used in the multiple-access collision channel without feedback. The number of codewords in a conflict-avoiding code is the number of potential users that can be supported in the system. In this paper, a new upper bound on the size of constant-weight conflict-avoiding codes is proved. This upper bound is general in the sense that it is applicable to all code lengths and all Hamming weights. Several existing constructions for conflict-avoiding codes, which are known to be optimal for Hamming weights equal to four and five, are shown to be optimal for all Hamming weights in general. |
| Auteurs: Shum, K. W.;Wong, W. S.;Chen, C. S.; |
| Apparue dans: IEEE Transactions on Information Theory |
| Date publication: 07.-2010, volume: 56, issue:7, pages: 3265 - 3276 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Generalized Delayed Signal Cancellation Method for Detecting Fundamental-Frequency Positive-Sequence Three-Phase Signals |
Résumé:
A novel scheme for obtaining the fundamental-frequency positive-sequence grid voltage vector based on a generalization of the delayed signal cancellation method is proposed in this paper. The technique is implemented by sampling and storing the instantaneous $alphabeta$ voltage vector. A mathematical transformation is then proposed through which the current and delayed voltage vectors are combined. It is shown that the proposed transformation has unity gain for the fundamental-frequency positive-sequence voltage vector, while its gain is equal to zero for some chosen components. Cascaded transformations can then be used for eliminating the fundamental-frequency negative-sequence vector, as well as chosen positive- and negative-sequence harmonic vector components and, thus, for accurately obtaining the fundamental-frequency positive-sequence voltage vector. The output of the last transformation block is input to a synchronous reference frame phase-locked loop for detecting frequency and position of the positive-sequence vector. A proposal for making the scheme frequency adaptive is also presented. The good performance of the proposed method is verified with simulations and experiments by using distorted and unbalanced signals, containing fundamental-frequency as well as positive- and negative-sequence harmonic components. The proposed method frequency adaptation capability is also verified. |
| Auteurs: Neves, F. A. S.;Cavalcanti, M. C.;de Souza, H. E. P.;Bradaschia, F.;Bueno, E. J.;Rizo, M.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1816 - 1825 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Generalized Drift-Diffusion Model for Rectifying Schottky Contact Simulation |
Résumé:
We present a discussion on the modeling of Schottky barrier rectifying contacts (diodes) within the framework of partial-differential-equation-based physical simulations. We propose a physically consistent generalization of the drift-diffusion model to describe the boundary layer close to the Schottky barrier where thermionic emission leads to a non-Maxwellian carrier distribution, including a novel boundary condition at the contact. The modified drift-diffusion model is validated against Monte Carlo simulations of a GaAs device. The proposed model is in agreement with the Monte Carlo simulations not only in the current value but also in the spatial distributions of microscopic quantities like the electron velocity and concentration. |
| Auteurs: Traversa, F. L.;Bertazzi, F.;Bonani, F.;Donati Guerrieri, S.;Ghione, G.;Perez, S.;Mateos, J.;Gonzalez, T.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1539 - 1547 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Generalized Synthesis Procedure for Low-Profile, Frequency Selective Surfaces With Odd-Order Bandpass Responses |
Résumé:
We present a generalized synthesis procedure for designing low-profile frequency selective surfaces (FSS) with bandpass responses of odd-order (N = 3,5,7,...). The FSSs designed using this technique use a combination of resonant and non-resonant sub-wavelength constituting unit cells with unit cell dimensions and periodicities in the order of 0.15 λ0, where λ0 is the free space wavelength. The main advantage of using this technique, compared to traditional FSS design techniques, is that it allows for the design of low-profile and ultrathin FSSs that can provide sharp frequency selectivity. An Nth order FSS designed using this technique typically has an electrical thickness in the order of ~ (N - 1) λ0/50 which is significantly smaller than the overall thickness of a traditionally designed Nth order FSS (~ (N - 1) λ0/4). The proposed synthesis procedure is validated for two FSS prototypes having third- and fifth-order bandpass responses. Principles of operation, detailed synthesis procedure, and implementation guidelines for this type of FSS are presented and discussed in this communication. |
| Auteurs: Behdad, N.;Al-Joumayly, M.A.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2460 - 2464 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Generalized System for Photoresponsive Membrane Rupture in Polymersomes |
Résumé:
Polymersomes are vesicles whose membranes comprise self-assembled block copolymers. It has recently been shown that co-encapsulating conjugated multiporphyrin dyes in a polymersome membrane with ferritin protein in the aqueous lumen confers photolability to the polymersome. In the present study, the photolability is shown to be extendable to vesicles containing dextran, an inert and inexpensive polysaccharide, as the luminal solute. How structural features of the polymersome/porphyrin/dextran composite affect its photoresponse is explored. Increasing dextran molecular weight, decreasing block copolymer molecular weight, and altering fluorophore-membrane interactions results in increasing the photoresponsiveness of the polymersomes. Amphiphilic interactions of the luminal encapsulant with the membrane coupled with localized heat production in the hydrophobic bilayer likely cause differential thermal expansion in the membrane and the subsequent membrane rupture. This study suggests a general approach to impart photoresponsiveness to any biomimetic vesicle system without chemical modification, as well as a simple, bio-inert method for constructing photosensitive carriers for controlled release of encapsulants. |
| Auteurs: Neha P. Kamat, Gregory P. Robbins, Jeff Rawson, Michael J. Therien, Ivan J. Dmochowski, Daniel A. Hammer |
| Apparue dans: Advanced Functional Materials |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Global Approach for Modeling and Analysis of Edge-Coupled Traveling-Wave Terahertz Photoconductive Sources |
Résumé:
In this paper, a global and geometry-independent approach is proposed for accurate analysis of edge-coupled continuous wave (CW) traveling-wave terahertz photomixer sources. All major physical phenomena involved in the operation of such devices are included in three interconnected solvers, which are combined as a unified analysis tool. A photonic solver is developed to find the optical intensity across the fast photoabsorbing region from which the carrier generation rate is determined. A semiconductor solver is used to study the charge carrier transport inside the photoconductive region through drift-diffusion model, and to predict the generated photocurrent with the beat frequency of two CW lasers. An electromagnetic solver is introduced to rigorously calculate the coupled terahertz signal into the guiding transmission line through a Lorentz reciprocity theorem. Theoretical formulation behind each solver is discussed in detail, and numerical results from each solver are presented. The proposed approach is a powerful tool for global optimization of the photoconductive sources, especially for maximizing the optical-to-terahertz power conversion. |
| Auteurs: Neshat, M.;Saeedkia, D.;Rezaee, L.;Safavi-Naeini, S.; |
| Apparue dans: IEEE Transactions on Microwave Theory and Techniques |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 1952 - 1966 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Graphene Oxide·Streptavidin Complex for Biorecognition - Towards Affinity Purification |
Résumé:
In our postgenomic era, understanding of protein-protein interactions by characterizing the structure of the corresponding protein complex is becoming increasingly important. An important problem is that many protein complexes are only stable for a few minutes. Dissociation will occur when using the typical, time-consuming purification methods such as tandem affinity purification and multiple chromatographic separations. Therefore, there is an urgent need for a quick and efficient protein-complex purification method for 3D structure characterization. The graphene oxide (GO)·streptavidin complex is prepared via a GO·biotin·streptavidin strategy and used for affinity purification. The complex shows a strong biotin recognition capability and an excellent loading capacity. Capturing biotinylated DNA, fluorophores and Au nanoparticles on the GO·streptavidin complexes demonstrates the usefulness of the GO·streptavidin complex as a docking matrix for affinity purification. GO shows a high transparency towards electron beams, making it specifically well suited for direct imaging by electron microscopy. The captured protein complex can be separated via a filtration process or even via on-grid purification and used directly for single-particle analysis via cryo-electron microscopy. Therefore, the purification, sample preparation, and characterization are rolled into one single step. |
| Auteurs: Zunfeng Liu, Linhua Jiang, Federica Galli, Igor Nederlof, René C. L. Olsthoorn, Gerda E. M. Lamers, Tjerk. H. Oosterkamp, Jan Pieter Abrahams |
| Apparue dans: Advanced Functional Materials |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Handheld Programmable-Logic-Device-Based Temperature and Relative-Humidity Sensor, Processor, and Display System Platform for Automation and Control of Industry Processes |
Résumé:
The development, testing, and validation of a small versatile battery-powered handheld programmable-logic-device (PLD)-based temperature and relative-humidity (RH) sensor, processor, and display system platform is addressed in this paper. An initial and illustrative application of the platform, which is used for its validation—temperature and RH sensing, calculation, and display of equilibrium moisture content of wood, is described. The platform may be utilized for computation and display of a range of temperature- and RH-sensitive metrics/parameters of importance to other process industries. The cost of the platform is important but not the highest priority. As illustrated in the wood-process-industry application of the platform, a higher priority is an ability to efficiently explore, implement, and compare, in a timely manner, different processor microarchitectures and display system formats which may be used in the calculation and display of any process-industry temperature- and/or RH-dependent process metric(s). This could include simultaneous calculation and display of multiple metrics which are a function of temperature and RH. After comparison, a best processor microarchitecture and display system can then be chosen and implemented based on specific industry process application performance/cost and other requirements. A PLD-based sensor, processor, and display system platform offers this opportunity. |
| Auteurs: Tangirala, K. P.;Heath, J. R.;Radun, A.;Conners, T. E.; |
| Apparue dans: IEEE Transactions on Industry Applications |
| Date publication: 07.-2010, volume: 46, issue:4, pages: 1619 - 1629 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A High Efficiency Flyback Converter With New Active Clamp Technique |
Résumé:
This paper proposes a flyback converter with a new noncomplementary active clamp control method. With the proposed control method, the energy in the leakage inductance can be fully recycled. The soft switching can be achieved for the main switch and the absorbed leakage energy is transferred to the output and input side. Compared to the conventional active clamp technique, the proposed methods can achieve high efficiency both for heavy-load and light-load condition, and the efficiency is almost not affected by the leakage inductance. The detailed operation principle and design considerations are presented. Performance of the proposed circuit is validated by the experimental results from a 16 V/4 A prototype. |
| Auteurs: Zhang, J.;Huang, X.;Wu, X.;Qian, Z.; |
| Apparue dans: IEEE Transactions on Power Electronics |
| Date publication: 07.-2010, volume: 25, issue:7, pages: 1775 - 1785 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments |
Résumé:
Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accuracy are limited by the convolved transverse spot size and pointing jitter of the beam. In this paper we present an electron energy spectrometer consisting of two magnets designed specifically for laser wakefield experiments. In the primary magnet the field is produced by permanent magnets. A second optional electromagnet can be used to obtain better resolution for electron energies above 75 MeV. The spectrometer has an acceptance of 2.5–400 MeV (Emax/Emin>100) with a resolution of better than 1% rms for electron energies above 25 MeV. This high resolution is achieved by refocusing electrons in the energy plane and without any postprocessing image deconvolution. Finally, the spectrometer employs two complimentary detection mechanisms: (1) absolutely calibrated scintillation screens imaged by cameras outside the vacuum chamber and (2) an array of scintillating fibers coupled to a low-noise charge-coupled device. |
| Auteurs: Sears, Christopher M. S.;Cuevas, Sofia Benavides;Schramm, Ulrich;Schmid, Karl;Buck, Alexander;Habs, Dieter;Krausz, Ferenc;Veisz, Laszlo; |
| Apparue dans: Review of Scientific Instruments |
| Date publication: 07.-2010, volume: 81, issue:7, pages: 073304 - 073304-7 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A high-temperature high-pressure calorimeter for determining heats of solution up to 623 K |
Résumé:
A high-temperature high-pressure isoperibol calorimeter for determining the heats of solution and reaction of very dilute substances in water (10-4 m) at temperatures up to 623 K is described. The energies of vaporization of water at steam saturation pressure were measured as a function of temperature and the results agree with the corresponding values from steam tables to better than 0.08±0.18%. The novelties of the present instrument relative to flow type heat capacity calorimeters are that measurements can be made at orders of magnitude lower concentrations and that measurement of heat of reaction involving solids or gases or in the presence of high concentrations of supporting electrolytes, acids, and bases is possible. Furthermore, the advantage of using enthalpy data over heat capacity data for calculations of the standard state Gibbs free energies of electrolytes is that the experimental heat data of this research need only be integrated once to derive higher temperature free energy data from lower temperatures. The derived heat capacities can be used mathematically to obtain free energies by double integration. However, the resulting errors are much smaller than if experimental aqueous heat capacities were used for the integrations. |
| Auteurs: Djamali, Essmaiil;Turner, Peter J.;Murray, Richard C.;Cobble, James W.; |
| Apparue dans: Review of Scientific Instruments |
| Date publication: 07.-2010, volume: 81, issue:7, pages: 075105 - 075105-6 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Highly Effective Impulse Noise Detection Algorithm for Switching Median Filters |
Résumé:
Under the framework of switching median filtering, a highly effective algorithm for impulse noise detection is proposed aiming at providing solid basis for subsequent filtering. This algorithm consists of two iterations to make the decision as accurate as possible. Two robust and reliable decision criteria are proposed for each iteration. Extensive simulation results show that the false alarm rate and miss detection rate of the proposed algorithm are both very low and substantially outperform existing state-of-the-art algorithms. At the same time, the proposed algorithm is in principle simpler as it is intuitive and it is easy to implement as it has uncomplicated structure and few codes. |
| Auteurs: Duan, F.;Zhang, Y.-J.; |
| Apparue dans: IEEE Signal Processing Letters |
| Date publication: 07.-2010, volume: 17, issue:7, pages: 647 - 650 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Hybrid Measurement Approach for Wideband Characterization and Modeling of Power Transformers |
Résumé:
This paper describes a hybrid procedure for wideband characterization and modeling of power transformer behavior from frequency sweep measurements. The approach is based on measuring corresponding sets of voltage and current vectors that are associated with short circuit and open circuit conditions. These vectors are stacked side-by-side in two matrices which are used for computing the short circuit admittance matrix. This hybrid approach is shown to give more information about the transformer behavior than the traditional approach of measuring the admittance matrix directly under short-circuit conditions, which tends to corrupt the small eigenvalues associated with open-circuit conditions. From the obtained admittance matrix, a pole-residue model is extracted via vector fitting and passivity enforcement, thereby giving a model ready for EMTP simulation. The accuracy of the small eigenvalues is retained by using a modal formulation in the fitting and passivity enforcement step. Application to a distribution transformer shows that the hybrid approach can greatly improve the accuracy of time-domain simulations involving high-impedance terminations. |
| Auteurs: Gustavsen, B.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1932 - 1939 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A hybrid multi-agent based particle swarm optimization algorithm for economic power dispatch |
Résumé:
This paper presents a new multi-agent based hybrid particle swarm optimization technique (HMAPSO) applied to the economic power dispatch. The earlier PSO suffers from tuning of variables, randomness and uniqueness of solution. The algorithm integrates the deterministic search, the Multi-agent system (MAS), the particle swarm optimization (PSO) algorithm and the bee decision-making process. Thus making use of deterministic search, multi-agent and bee PSO, the HMAPSO realizes the purpose of optimization. The economic power dispatch problem is a non-linear constrained optimization problem. Classical optimization techniques like direct search and gradient methods fails to give the global optimum solution. Other Evolutionary algorithms... |
| Auteurs: Rajesh, Kumar , Devendra, Sharma , Abhinav, Sadu |
| Apparue dans: International Journal of Electrical Power & Energy Systems |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Hybrid Nested Partitions Algorithm for Banking Facility Location Problems |
Résumé:
The facility location problem has been studied in many industries including banking network, chain stores, and wireless network. Maximal covering location problem (MCLP) is a general model for this type of problems. Motivated by a real-world banking facility optimization project, we propose an enhanced MCLP model which captures the important features of this practical problem, namely, varied costs and revenues, multitype facilities, and flexible coverage functions. To solve this practical problem, we apply an existing hybrid nested partitions algorithm to the large-scale situation. We further use heuristic-based extensions to generate feasible solutions more efficiently. In addition, the upper bound of this problem is introduced to study the quality of solutions. Numerical results demonstrate the effectiveness and efficiency of our approach. |
| Auteurs: Li Xia;Wenjun Yin;Jin Dong;Wu, T.;Ming Xie;Yanjia Zhao; |
| Apparue dans: IEEE Transactions on Automation Science and Engineering |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 654 - 658 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Hybrid Passive Filter Configuration for VAR Control and Harmonic Compensation |
Résumé:
This paper proposes a novel topology for a three-phase hybrid passive filter (HPF) to compensate for reactive power and harmonics. The HPF consists of a series passive filter and a thyristor-controlled-reactor-based variable-impedance shunt passive filter (SPF). A mutual-inductance design concept is used to reduce the series passive filter inductance rating. The special features of the proposed HPF system are as follows: 1) insensitivity to source-impedance variations; 2) no series or parallel resonance problems; 3) fast dynamic response; and 4) significant size reduction in an SPF capacitor. The performance of the proposed HPF system is validated by simulation, as well as by experimentation, under different load conditions. Experimental and simulation results show that the proposed system can effectively compensate all voltage and current harmonics and reactive power for large nonlinear loads. |
| Auteurs: Hamadi, A.;Rahmani, S.;Al-Haddad, K.; |
| Apparue dans: IEEE Transactions on Industrial Electronics |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 2419 - 2434 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A hybrid strategy for the time- and energy-efficient trajectory planning of parallel platform manipulators |
Résumé:
In planning the trajectories of motor-driven parallel platform manipulators, the objective is to identify the trajectory which accomplishes the assigned motion with the minimal travel time and energy expenditure subject to the constraints imposed by the kinematics and dynamics of the manipulator structure. In this study, the possible trajectories of the manipulator are modeled using a parametric path representation, and the optimal trajectory is then obtained using a hybrid scheme comprising the particle swarm optimization method and the local conjugate gradient method. The numerical results confirm the feasibility of the optimized trajectories and show that the hybrid scheme is not... |
| Auteurs: Chun-Ta, Chen , Te-Tan, Liao |
| Apparue dans: Robotics and Computer-Integrated Manufacturing |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Hypergraph Approach to Linear Network Coding in Multicast Networks |
Résumé:
Network coding is a promising generalization of routing which allows a node to generate output messages by encoding its received messages. A typical scenario where network coding offers unique advantages is a multicast network where a source node generates messages and multiple receivers collect the messages. In a multicast network, linear network codes are preferred due to its sufficiency and simplicity. In this paper, we propose an approach to transforming the linear coding problem into a graph theory problem. By utilizing hypergraphs, we model the linear codes by constructing a pseudodual graph of the multicast network. Then, a valid linear code is equivalent to a cover in the pseudodual graph satisfying some constraints. By iterative refinements, an eligible cover can be found in polynomial time. Moreover, we propose several preprocessing algorithms to further reduce the computation time required by the iterative refinements by reducing the graph size before transformation. An important contribution of this work is that the proposed approach can be readily extended to solve many minimal network coding problems. By assigning different weights to edges, minimal network coding problems are reduced to the shortest path problem in the pseudodual graph. Our simulation results show that the proposed preprocessing algorithms can reduce the computation time by about 40-50 percent in a medium size multicast network compared to the scheme without preprocessing algorithms, and the throughput of the system with network coding is 25 percent higher than that with the traditional approach of multiple multicast trees. |
| Auteurs: Yang, Min;Yang, Yuanyuan; |
| Apparue dans: IEEE Transactions on Parallel and Distributed Systems |
| Date publication: 07.-2010, volume: 21, issue:7, pages: 968 - 982 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A K-Band High-Voltage Four-Way Series-Bias Cascode Power Amplifier in 0.13 $mu$ m CMOS |
Résumé:
This letter reports a K-band high-voltage power amplifier delivering 100 mW output power in CMOS technology. The amplifier used series-bias of four cascode power cells to increase operating voltage and achieve high output power. The two-stage series-bias amplifier showed a maximum small-signal gain of 19.5 dB, an output power of 20 dBm, and a PAE of 12.4% at 21 GHz. The results of this study will be useful for realizing a fully integrated single-chip transceiver at microwave and millimeter-wave frequencies. |
| Auteurs: Jong-Wook Lee;Byung-Sung Kim; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 408 - 410 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Kernel-Based Nonparametric Regression Method for Clutter Removal in Infrared Small-Target Detection Applications |
Résumé:
Small-target detection in infrared imagery with a complex background is always an important task in remote-sensing fields. Complex clutter background usually results in serious false alarm in target detection for low contrast of infrared imagery. In this letter, a kernel-based nonparametric regression method is proposed for background prediction and clutter removal, furthermore applied in target detection. First, a linear mixture model is used to represent each pixel of the observed infrared imagery. Second, adaptive detection is performed on local regions in the infrared image by means of kernel-based nonparametric regression and two-parameter constant false alarm rate (CFAR) detector. Kernel regression, which is one of the nonparametric regression approaches, is adopted to estimate complex clutter background. Then, CFAR detection is performed on “pure” target-like region after estimation and removal of clutter background. Experimental results prove that the proposed algorithm is effective and adaptable to small-target detection under a complex background. |
| Auteurs: Gu, Y.;Wang, C.;Liu, B.;Zhang, Y.; |
| Apparue dans: IEEE Geoscience and Remote Sensing Letters |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 469 - 473 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Key Exchange Method for Intelligent Electronic Devices in Distribution Automation |
Résumé:
The use of communication networks and intelligent electronic devices (IEDs) for power systems is becoming more common and more necessary. Changes in the power system structure, changes in requirements and the necessity to have easy access to accurate data have led to the need for communication systems. Due to these changes, communication systems with IEDs in power companies expose the safety-critical power companies' network to the multitude security problems of communication networks. This paper proposes a method called multiple channel secure acknowledging multicast, which merges the tasks of acknowledgment and key changes in a simple and direct manner to make exposed IEDs more secure in distribution automation. |
| Auteurs: Kim, M.;Metzner, J. J.; |
| Apparue dans: IEEE Transactions on Power Delivery |
| Date publication: 07.-2010, volume: 25, issue:3, pages: 1458 - 1464 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Lab-Scale Alternative Interconnection Solution of Semiconductor Dice Compatible with Power Modules 3-D Integration |
Résumé:
Increase in the power density of power modules requires an interconnection technology alternative to wire-bonding technology. Emerging interconnection technologies allow a 3-D packaging of power modules. A proposal of interconnection solution for the power semiconductor dice is presented here; it is based on copper microposts that are electroplated on topside of the die. The die with its microposts is then attached to a top direct-bonding copper (DBC) substrate using a copper/tin transient liquid phase technique. The assembly of the backside of the die to a bottom DBC substrate is processed concurrently using the same transient liquid phase technique. The benefits or limitations of the substrate on the assembly are not discussed in this letter. Manufacturing and electrical characterization of a power semiconductor die with the microposts interconnection is presented in detail. |
| Auteurs: Ménager, L.;Soueidan, M.;Allard, B.;Bley, V.;Schlegel, B.; |
| Apparue dans: IEEE Transactions on Power Electronics |
| Date publication: 07.-2010, volume: 25, issue:7, pages: 1667 - 1670 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Level Set Formulation of Geodesic Curvature Flow on Simplicial Surfaces |
Résumé:
Curvature flow (planar geometric heat flow) has been extensively applied to image processing, computer vision, and material science. To extend the numerical schemes and algorithms of this flow on surfaces is very significant for corresponding motions of curves and images defined on surfaces. In this work, we are interested in the geodesic curvature flow over triangulated surfaces using a level set formulation. First, we present the geodesic curvature flow equation on general smooth manifolds based on an energy minimization of curves. The equation is then discretized by a semi-implicit finite volume method (FVM). For convenience of description, we call the discretized geodesic curvature flow as dGCF. The existence and uniqueness of dGCF are discussed. The regularization behavior of dGCF is also studied. Finally, we apply our dGCF to three problems: the closed-curve evolution on manifolds, the discrete scale-space construction, and the edge detection of images painted on triangulated surfaces. Our method works for compact triangular meshes of arbitrary geometry and topology, as long as there are no degenerate triangles. The implementation of the method is also simple. |
| Auteurs: Wu, Chunlin;Tai, Xuecheng; |
| Apparue dans: IEEE Transactions on Visualization and Computer Graphics |
| Date publication: 07.-2010, volume: 16, issue:4, pages: 647 - 662 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Lightweight Sanity Check for Implemented Architectures |
Résumé:
Architecture evaluations offer many benefits, including the early detection of problems and a better understanding of a system's possibilities. Although many methods for evaluating architectures are available, studies have shown that industry's adoption of architecture evaluations is low. A reason for this lack of adoption is the limited out-of-the-box process and tool support available to start performing architecture reviews. This article introduces the lightweight sanity check for implemented architectures (LiSCIA) evaluation method. LiSCIA can be used out of the box to perform a first architectural evaluation of a system. The check is based on years of experience in evaluating the maintainability of software systems. By periodically performing this check, developers and project managers can control the implemented architecture's erosion as the system (and its requirements) evolves over time. |
| Auteurs: Bouwers, Eric;van Deursen, Arie; |
| Apparue dans: IEEE Software |
| Date publication: 07.-2010, volume: 27, issue:4, pages: 44 - 50 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Low Overhead DPA Countermeasure Circuit Based on Ring Oscillators |
Résumé:
Side-channel attacks, particularly differential power analysis (DPA) attacks, are efficient ways to extract secret keys of the attacked devices by leaked physical information. To resist DPA attacks, hiding and masking methods are commonly used, but it usually resulted in high area overhead and performance degradation. In this brief, a DPA countermeasure circuit based on digital controlled ring oscillators is presented to efficiently resist the first-order DPA attack. The implementation of the critical S-box of the advanced encryption standard (AES) algorithm shows that the area overhead of a single S-box is about 19% without any extra delay in the critical path. Moreover, the countermeasure circuit can be mounted onto different S-box implementations based on composite field or look-up table (LUT). Based on our approach, a DPA-resistant AES chip can be proposed to maintain the same throughput with less than 2K extra gates. |
| Auteurs: Liu, P.-C.;Chang, H.-C.;Lee, C.-Y.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 546 - 550 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Low Phase Noise Quadrature VCO Using Symmetrical Tail Current-Shaping Technique |
Résumé:
This letter presents a new symmetrical tail current-shaping technique to improve the phase noise of a quadrature voltage-controlled oscillator (QVCO). This proposed QVCO consists of two first-harmonic injection-locked oscillators (ILOs) and the outputs are injected back to the gates of the QVCO's tail transistors in order to shape the tail currents. A switching current path is provided between the two tail current sources in order to eliminate the asymmetric phenomenon of the tail currents. The measured phase noise can be improved by 4 dB using this technique. This CMOS LC-tank QVCO has been implemented using the TSMC 0.18 μm mixed-signal/RF CMOS 1P6M technology and the die area is 0.7 × 1.1 mm2. The total power consumption is 11.2 mW at the supply voltage of 1.4 V. The measured phase noise at 1 MHz offset is -119.3 dBc/Hz at the oscillation frequency of 5.28 GHz. The figure of merit (FOM) of the proposed QVCO is -183 dBc/Hz. |
| Auteurs: I-Shing Shen;Tze-Che Huang;Jou, C.F.; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 399 - 401 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A low power CMOS compatible embedded EEPROM for passive RFID tag |
Résumé:
A 512-bit low-voltage CMOS-compatible EEPROM is developed and embedded into a passive RFID tag chip using 0.18?m CMOS technology. The write voltage is halved by adopting a planar EEPROM cell structure. The wide Vth distribution of as-received memory cells is mitigated by an initial erase and further reduced by an in-situ regulated erase operation using negative feedback. Although over-programmed charges leak from the floating gates over several days, the remaining charges are retained without further loss. The 512-bit planar EEPROM occupies 0.018mm2 and consumes 14.5 and 370?W for read and write at 85°C, respectively. |
| Auteurs: Kyoung-Su, Lee , Jung-Hoon, Chun , Kee-Won, Kwon |
| Apparue dans: Microelectronics Journal |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Low-Complexity Cyclostationary-Based Spectrum Sensing for UWB and WiMAX Coexistence With Noise Uncertainty |
Résumé:
This paper focuses on a cognitive radio approach based on a noncooperative spectrum-sensing technique that is suitable for applications in detection and avoidance (DAA) schemes to allow coexistence between ultrawideband multiband (secondary user) and Worldwide Interoperability for Microwave Access (WiMAX; primary user) systems and, hence, improve spectral efficiency. In particular, the cyclostationary property of WiMAX signals due to the cyclic prefix is exploited here. The spectrum-sensing method devised in this paper is a statistical test that relies on cyclostationarity, and it belongs to the class of the single-cycle detector. The performance of the proposed detector, in terms of primary-user detection probability, is derived by computer simulations. The results obtained highlight that the proposed approach enables efficient downlink detection under conditions of low signal-to-noise ratio (SNR) and noise uncertainty. The implementation complexity of the proposed method is also discussed here to highlight advantages with respect to previously proposed alternatives. Finally, an analytical approach is presented to derive the false-alarm probability to allow the implementation of a constant false-alarm rate detector. In addition, the use of an efficient interference-mitigation scheme is also considered to improve the bit-error-rate performance. |
| Auteurs: Tani, A.;Fantacci, R.; |
| Apparue dans: IEEE Transactions on Vehicular Technology |
| Date publication: 07.-2010, volume: 59, issue:6, pages: 2940 - 2950 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A low-cost millimeter wave interferometer for remote vibration sensing |
Résumé:
Remote sensing of ground vibration is a key tool in the detection of shallowly buried objects, such as land mines. Millimeter wave systems show promise for replacing laser Doppler vibrometers as the key sensing technology on the grounds of reduced cost and because they provide a larger (10 cm versus 1 mm), more robust sensor footprint. We have developed a double-conversion interferometer operating at 39 GHz that can be built for about $10 000. The system employs quadrature detection in order to provide reliable sensitivity over wavelength-sized changes in target range. Laboratory tests show that it can estimate sinusoidal ground motion from a 1 s time series with an uncertainty of about 5 μm. |
| Auteurs: Smith, Martin L.;Scales, John A.;Weiss, Manoja;Zadler, Brian; |
| Apparue dans: Journal of Applied Physics |
| Date publication: 07.-2010, volume: 108, issue:2, pages: 024902 - 024902-5 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Low-Cost Very Large Scale Integration Architecture for Multistandard Inverse Transform |
Résumé:
In this brief, a low-cost very large scale integration (VLSI) architecture is designed for multistandard inverse transform. The proposed architecture is used in multistandard decoder of MPEG-2, MPEG-4 ASP, H.264/AVC and VC-1. Two circuit share strategies, factor share (FS) and adder share (AS), are applied to the inverse transform architecture for saving its circuit resource. It is shown that the proposed multistandard inverse transform architecture can support the real-time decoding of 1920 $times$ 1080@60 Hz high-definition video at the cost of low circuit resource. |
| Auteurs: Qi, H.;Huang, Q.;Gao, W.; |
| Apparue dans: IEEE Transactions on Circuits and Systems II: Express Briefs |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 551 - 555 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Low-Field Mobility Model for Bulk, Ultrathin Body SOI and Double-Gate n-MOSFETs With Different Surface and Channel Orientations—Part I: Fundamental Principles |
Résumé:
An easy-to-implement electron mobility model that accurately predicts low-field mobility in the channel of bulk MOSFETs and UTB-SOI FETs fabricated on different crystal orientations is developed. The model accounts for the influence of surface orientation and in-plane current-flow direction on effective masses, subband repopulation, and scattering rates. The paper is divided into two parts. In Part I, the general features of the model are presented, taking into account phonon, Coulomb, and surface roughness scattering. Band and repopulation effects are addressed based on the solution of the Schrödinger–Poisson equations. The effects of interface states and ultrathin body are treated in Part II. |
| Auteurs: Silvestri, L.;Reggiani, S.;Gnani, E.;Gnudi, A.;Baccarani, G.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1567 - 1574 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Low-Field Mobility Model for Bulk, Ultrathin Body SOI and Double-Gate n-MOSFETs With Different Surface and Channel Orientations—Part II: Ultrathin Silicon Films |
Résumé:
In this paper, together with the accompanying Part I, an easy-to-implement electron mobility model that accurately predicts low-field mobility in bulk MOSFETs and UTB-SOI FETs fabricated on different crystal orientations is developed. In Part I, the general features of the model have been presented. In this Part II, the effects induced by extremely small silicon thicknesses are addressed. These effects include the scattering induced by interface states and silicon thickness fluctuations, intervalley-phonon scattering suppression, and surface optical phonons. Besides, corrections necessary for double-gate FETs are considered. This allows the validity of the model presented in Part I to be extended to single- and double-gate FETs with silicon thicknesses as small as about 2.5 nm. |
| Auteurs: Silvestri, L.;Reggiani, S.;Gnani, E.;Gnudi, A.;Baccarani, G.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1575 - 1582 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Low-Intrusion Load and Efficiency Evaluation Method for In-Service Motors Using Vibration Tests With an Accelerometer |
Résumé:
This paper presents a novel low-intrusion load and efficiency evaluation method for in-service induction motors based on vibration measurements. This method enhances the traditional vibration analysis by providing motor load and efficiency information in addition to the mechanical health information. The application is in multimotor plants, where individual motor monitoring is too expensive to implement yet where motor operating conditions need to be known to work at improved plant efficiency. The vibration signature of the machine, measured by an accelerometer and processed by fast Fourier transform (FFT) is used to extract frequencies defining shaft speed and the supply frequency. This data, in conjunction with the basic motor performance data, enables the determination of the actual load and indirectly, the efficiency which the motor is operating at. For motors supplied form a variable-speed drive (VSD), the loss segregation method is used to yield the motor losses indirectly and thus, the efficiency. |
| Auteurs: Zhang, H.;Zanchetta, P.;Bradley, K. J.;Gerada, C.; |
| Apparue dans: IEEE Transactions on Industry Applications |
| Date publication: 07.-2010, volume: 46, issue:4, pages: 1341 - 1349 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A low-noise amplifier design using the performance limitations of a microwave transistor for the ultra-wideband applications |
Résumé:
In this work, a design method of an ultra-wideband, low-noise amplifier (LNA) is put forward exploiting the performance limitations of a single high-quality discrete transistor. For this purpose, the compatible (noise F, input VSWR Vi, gain GT) triplets and their (ZS, ZL) terminations of the microwave transistor are used for the feasible design target space with the minimum noise Fmin(f), maximum gain GTmax(f), and a low constant input VSWR Vireq using the optimum noise impedance Zopt(f), and the maximum gain termination ZLmax(f) over the available bandwidth B. In the next stage, this multiobjective design process is reduced to the Darlington synthesis of the corresponding Zopt(f), ZLmax(f) terminations using the unit elements and short-circuited stubs in the T-, L-, [Pi]-configurations. This synthesis is transformed to an optimization process with the determined feasible target space and optimization variables. Here, particle swarm intelligence is successfully implemented as a comparatively simple and efficient optimization tool in both verification of the design target space and the design process of the input and output matching circuits. Typical design examples are given with their challenging performances in the simple matching configurations realizable by the microstrip line technology. Furthermore, the performances of the synthesized amplifiers are compared using an analysis programme in MATLAB code and a microwave system simulator and verified to agree with each other and the design target space. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. |
| Auteurs: Filiz Güne[scedil], Salih Demirel, Ufuk Özkaya |
| Apparue dans: International Journal of RF and Microwave Computer-Aided Engineering |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A low-voltage band-gap reference circuit with second-order analyses |
Résumé:
A new band-gap reference (BGR) circuit employing sub-threshold current is proposed for low-voltage operations. By employing the fraction of VBE and the sub-threshold current source, the proposed BGR circuit with chip area of 0.029mm2 was fabricated in the standard 0.18µm CMOS triple-well technology. It generates reference voltage of 170 mV with power consumption of 2.4µW at supply voltage of 1 V. The agreement between simulation and measurement shows that the variations of reference voltage are 1.3 mV for temperatures from -20 to 100[compfn]C, and 1.1 mV per volt for supply voltage from 0.95 to 2.5 V, respectively. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Chao-Jui Liang, Chiu-Chiao Chung, Hongchin Lin |
| Apparue dans: International Journal of Circuit Theory and Applications |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A mathematical model for an upper convected Maxwell fluid with an elastic core: Study of a limiting case |
Résumé:
In this paper we formulate a mathematical model for a continuum which behaves like an upper convected visco-elastic Maxwell fluid if the stress is above a certain threshold and like a neo-Hookean elastic solid if the stress is below that threshold. The constitutive equations for each phase are derived within the context of the theory of natural configurations and by means of the criterion of the maximization of the rate of dissipation [11]. We then focus on a limiting case in which the continuum becomes an elastic-rigid body. In this limiting case the constitutive relation of the material becomes implicit... |
| Auteurs: Lorenzo, Fusi , Angiolo, Farina |
| Apparue dans: International Journal of Engineering Science |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Matrix Pseudoinversion Lemma and Its Application to Block-Based Adaptive Blind Deconvolution for MIMO Systems |
Résumé:
The matrix inversion lemma gives an explicit formula of the inverse of a positive definite matrix ${mmb A}$ added to a block of dyads (represented as ${mmb{BB}}^{{rm H}}$) as follows: ${(!{mmb A}+{mmb{BB}}^{{rm H}})}^{-1}!=!{mmb A}^{-1}-{mmb A}^{-1}{mmb B}{({mmb I}+{mmb B}^{{rm H}}{mmb A}^{-1}{mmb B})}^{-1}{mmb B}^{{rm H}}{mmb A}^{-1}$. It is well known in the literature that this formula is very useful to develop a block-based recursive least squares algorithm for the block-based recursive identification of linear systems or the design of adaptive filters. We extend this result to the case when the matrix ${mmb A}$ is singular and present a matrix pseudoinversion lemma along with some illustrative examples. Based on this result, we propose a block-based adaptive multichannel superexponential algorithm. We present simulation results for the performance of the block-based algorithm in order to show the usefulness of the matrix pseudoinversion lemma. |
| Auteurs: Kohno, K.;Kawamoto, M.;Inouye, Y.; |
| Apparue dans: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1449 - 1462 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A matter of degrees |
Résumé:
What do you want to do during your career? If you're thinking about applying to a graduate program, you should know the answer to this question first—or at least have a good sense of your preferred direction. |
| Auteurs: Williamson, S.; |
| Apparue dans: IEEE Potentials |
| Date publication: 07.-2010, volume: 29, issue:4, pages: 23 - 26 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A meandering dual-mode bandpass filter with rectangular-loop perturbation |
Résumé:
A dual-mode bandpass filter is proposed that is composed of a meandering resonator and a small rectangular loop for the purpose of perturbation.Both the length and width of the rectangular loop could control the dual-mode resonant frequencies. A prototype filter is designed and fabricated with a center frequency of 2.45 GHz. The measured fractional bandwidth is 10.98%, insertion loss is 0.8 dB, and return loss is over 15 dB, which are in good agreement with the simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2356-2359, 2010; DOI 10.1002/mop.25454 |
| Auteurs: Rui Chu, Jun-Fa Mao, Liang Zhou |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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| » A Medium-Voltage Motor Drive With a Modular Multilevel PWM Inverter |
Résumé:
This paper describes the control and operating performance of a modular multilevel PWM inverter for a transformerless medium-voltage motor drive. The inverter is prominent in the modular arm structure consisting of a cascaded stack of multiple bidirectional chopper-cells. The dominant ac-voltage fluctuation with the same frequency as the motor (inverter) frequency occurs across the dc capacitor of each chopper-cell. The magnitude of the voltage fluctuation is inversely proportional to the motor frequency. This paper achieves theoretical analysis on the voltage fluctuation, leading to system design. A downscaled model rated at 400 V and 15 kW is designed and built up to confirm the validity and effectiveness of the nine-level (17-level in line-to-line) PWM inverter for a medium-voltage motor drive. |
| Auteurs: Hagiwara, M.;Nishimura, K.;Akagi, H.; |
| Apparue dans: IEEE Transactions on Power Electronics |
| Date publication: 07.-2010, volume: 25, issue:7, pages: 1786 - 1799 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Method of Obtaining Ice Concentration and Floe Size From Shipboard Oblique Sea Ice Images |
Résumé:
Digital cameras are widely used on research vessels to ascertain ice conditions in ice-infested seas. However, geometric distortion of images cannot be avoided if the camera is tilted relative to the sea surface. In this study, the geometric distortion induced by oblique photography was quantitatively estimated based on photogrammetric theory to enable accurate measurement of sea ice features. One accurate method of calculating the ice concentration and floe size was developed, and a corresponding simplified method was also tested. Proper selection of camera system parameters (camera height, tilt, and focal length) cannot only avoid possible errors induced by geometric distortion but also make full use of the image information. Additionally, oblique sea ice images obtained during the 2006 Winter Weddell Outflow Study were investigated using the methods developed here. The results revealed that the geometric distortion of oblique images could be accurately corrected by analyzing each image pixel and that the simplified method could be applied to ensure the precision and efficiency of calculating ice features. |
| Auteurs: Lu, P.;Li, Z.; |
| Apparue dans: IEEE Transactions on Geoscience and Remote Sensing |
| Date publication: 07.-2010, volume: 48, issue:7, pages: 2771 - 2780 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A method of solving scheduling problems using an improved guided genetic algorithm |
Résumé:
In this paper, an improved guided genetic algorithm is proposed for the job-shop scheduling problem. The proposed method is improved by a genetic algorithm using multipliers which can be adjusted during the search process. Simulation results based on some benchmark problems demonstrate that the proposed method can find better solutions than the genetic algorithm and the original guided genetic algorithm. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(8): 15-15, 2010; Published online in Wiley InterScience (). DOI 10.1002/ecj.10263 |
| Auteurs: Gyouhi Ou, Hiroki Tamura, Koichi Tanno, Zheng Tang |
| Apparue dans: Electronics and Communications in Japan |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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| » A Methodology for Extraction of the Density of Interface States in the Presence of Frequency Dispersion via the Conductance Technique |
Résumé:
The density of interface states in the presence of significant frequency dispersion arising from parasitic effects is extracted via the conductance technique. A complete electrical model is presented to highlight the complex nature of parasitic effects, which cannot be explained by conventional models. This technique is successfully applied to MOS capacitors with identical layers of $hbox{HfO}_{2}/ hbox{SiO}_{2}$ dielectrics but differing in the type of gate. The Poly/TiN gate gives a significant reduction of the EOT; however, the interface state density is found to have increased in comparison with the polysilicon gate. |
| Auteurs: Sicre, S. B. F.;De Souza, M. M.; |
| Apparue dans: IEEE Transactions on Electron Devices |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1642 - 1650 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A minirhizotron imaging system to identify roots expressing the green fluorescent protein |
Résumé:
The limited flexibility available in the configuration of commercial minirhizotron imaging systems makes it difficult to adapt these systems to new applications. It is also too expensive to introduce modifications, which are often very temporary to these systems at the end of the development process.In order to identify the roots of a single species in mixed plant stands, we developed a new minirhizotron imaging system that makes it possible to observe roots expressing green fluorescent protein (GFP). This system is based on affordable and easily obtainable components such as webcams. Here, we report a protocol to identify suitable webcams for... |
| Auteurs: Marc, Faget , Markus, Liedgens , Peter, Stamp , Patrick, Flütsch , Juan Manuel, Herrera |
| Apparue dans: Computers and Electronics in Agriculture |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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|
| » A Modified Bow-Tie Antenna for Improved Pulse Radiation |
Résumé:
The analysis, design, and realization of a modified bow-tie antenna optimized for impulse ground penetrating radar (GPR) applications is described. The proposed antenna shows improved properties important for GPR, which include its compact size (in comparison with a conventional bow-tie antenna) and ability to radiate UWB pulses with increased amplitude and very small late-time ringing. A substantial increase in the amplitude of the transmitted pulse is achieved by utilizing radiation from discontinuities introduced by the resistive loading employed in the antenna to suppress late-time ringing. By choosing an optimal distance between the antenna's feed point and the location of the resistive loading, radiations that occur from the antenna's feed point and the mentioned discontinuities at the resistive loading will combine constructively in the boreside direction of the antenna. As a result, one will observe a substantial increase of the amplitude of the transmitted pulse in the boreside direction. Furthermore, an analytical expression describing approximate time-harmonic current distribution is derived to indicate an optimal resistive loading profile for the proposed antenna. Additionally, the traveling-wave current distribution of the antenna is theoretically analyzed to examine the applicability of the obtained time-harmonic expression for pulse excitation. It has been found that when the antenna is resistively loaded both the time-harmonic and traveling-wave currents decay to approach nearly the same value at the end section of the antenna. As the amount of current at the antenna ends corresponds to the level of reflection which occurs there, the derived expression is found to be useful to indicate an optimal loading profile for the proposed antenna. A theoretical model of the proposed antenna has been developed to perform numerical analysis using a modified NEC-2 code. In addition, an experimental verification has been carried out and both the simulation and e-
-
xperiment confirmed the improved properties of the proposed antenna. |
| Auteurs: Lestari, A.A.;Bharata, E.;Suksmono, A.B.;Kurniawan, A.;Yarovoy, A.G.;Ligthart, L.P.; |
| Apparue dans: IEEE Transactions on Antennas and Propagation |
| Date publication: 07.-2010, volume: 58, issue:7, pages: 2184 - 2192 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A Molecular Brush Approach to Enhance Quantum Yield and Suppress Nonspecific Interactions of Conjugated Polyelectrolyte for Targeted Far-Red/Near-Infrared Fluorescence Cell Imaging |
Résumé:
A red-fluorescent conjugated polyelectrolyte (CPE, P2) is grafted with dense poly(ethylene glycol) (PEG) chains via click chemistry and subsequently modified with folic acid to form a molecular brush based cellular probe (P4). P4 self-assembles into a core-shell nanostructure in aqueous medium with an average size of 130 nm measured by laser light scattering. As compared to P2, P4 possesses not only a substantially higher quantum yield (11%), but also reduced nonspecific interactions with biomolecules in aqueous medium due to the shielding effect of PEG. In conjunction with its high photostability and low cytotoxicity, utilization of P4 as a far-red/near-infrared cellular probe allows for effective visualization and discrimination of MCF-7 cancer cells from NIH-3T3 normal cells in a high contrast, selective, and nonviral manner. This study thus demonstrates a flexible molecular brush approach to overcome the intrinsic drawbacks of CPEs for advanced bioimaging applications. |
| Auteurs: Kan-Yi Pu, Kai Li, Bin Liu |
| Apparue dans: Advanced Functional Materials |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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| » A Moment Ratio RFI Detection Algorithm That Can Detect Pulsed Sinusoids of Any Duty Cycle |
Résumé:
The kurtosis statistic is an effective detector of pulsed sinusoidal radio frequency interference (RFI) in a microwave radiometer, but it fails to detect RFI when the pulsed sinusoid is present for exactly half of the integration period. That is, the kurtosis is blind at an RFI duty cycle of 50%. In this letter, we explore the possibilities of using a higher order statistic to eliminate this detection blind spot in the kurtosis statistic and to improve RFI detection performance. The sixth-order statistic does have sensitivity at an RFI duty cycle of 50%, but sensitivity is relatively low. In addition, it has a sensitivity comparable with the kurtosis for short duty cycle RFI, under certain circumstances. |
| Auteurs: De Roo, R. D.;Misra, S.; |
| Apparue dans: IEEE Geoscience and Remote Sensing Letters |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 606 - 610 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A monopole antenna with a magneto-dielectric material and its MIMO application for 700 MHz-LTE-band |
Résumé:
This article presents an antenna with a magneto-dielectric material and its MIMO application for LTE-band.The proposed antenna is a folded monopole type and occupies a compact volume of 7.5 × 18.5 × 3.4 mm3. For reducing the size, obtaining the broad bandwidth, and enhancing the isolation performance, the magneto-dielectric material is applied as a supporter. The parameters of the magneto-dielectric material are [epsiv][prime] - j[epsiv][Prime]= 3.29-j0.09 and [mu][prime] - j[mu][Prime] = 2.01-j0.38 at 780 MHz. For evaluations of the MIMO application, the antenna has been measured in reverberation chamber. The Microwave Studio (MWS) is employed for optimizing the design parameters, and the simulated results are well agreed with those of the measured one. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2364-2367, 2010; DOI 10.1002/mop.25470 |
| Auteurs: Yong-Sun Shin, Seong-Ook Park |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A MRI and Polarized Gases Compatible Respirator and Gas Administrator for the Study of the Small Animal Lung: Volume Measurement and Control |
Résumé:
We have developed over the past years an experimental magnetic resonance imaging (MRI) and polarized gases compatible mechanical respirator for the study of the small experimental animal. The respirator has been successfully used for experiments both in the MRI setting for polarized $^3$He, $^{19}$F, and proton imaging as well as for functional measurements of the lungs. The new main pneumatic valve with the two integrated sensors for simultaneous lung pressure and volume measurements and the proportional valve to set the tidal volume of the respiration are described. It is shown how the device measures and controls the tidal volume of the lungs. |
| Auteurs: Kyriazis, A.;de Alejo, R. P.;Rodriguez, I.;Olsson, L. E.;Ruiz-Cabello, J.; |
| Apparue dans: IEEE Transactions on Biomedical Engineering |
| Date publication: 07.-2010, volume: 57, issue:7, pages: 1745 - 1749 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A multi-objective optimization approach for assessment of technical, commercial and environmental performance of microgrids |
Résumé:
This paper proposes a multi-objective optimization model to evaluate potential economic, technical and environmental benefits of Microgrid operation. Internalization of external costs such as induced by energy losses (network related) and CO2 emissions (environmentally related) is performed to address the interests of different agents within a single optimization framework. After presenting four reference operation strategies, a multi-layered scheduling algorithm based on genetic algorithm and linear/quadratic programming is introduced in detail. The algorithm is applied to a UK urban test grid with four different levels of penetration of distributed energy resources. The simulation results lead to the recommendation of a combined dispatch strategy that can simultaneously satisfy all constraints and provide a proper compromise for conflicting objectives of different stakeholders involved in energy supply chain. In particular, a Pareto front representation of the optimization results is also given to further illustrate the multi-objective nature of the problem. Copyright © 2010 John Wiley & Sons, Ltd. |
| Auteurs: Christine Schwaegerl, Liang Tao, Pierluigi Mancarella, Goran Strbac |
| Apparue dans: European Transactions on Electrical Power |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Multispectral Image Segmentation Method Using Size-Weighted Fuzzy Clustering and Membership Connectedness |
Résumé:
Clustering-based image segmentation is a well-known multispectral image segmentation method. However, as it inherently does not account for the spatial relation among image pixels, it often results in inhomogeneous segmented regions. The recently proposed membership-connectedness (MC)-based segmentation method considers the local and global spatial relations besides the fuzzy clustering stage to improve segmentation accuracy. However, the inherent spatial and intraclass redundancies in multispectral images might decrease the accuracy and efficiency of the method. This letter addresses these two problems and proposes a segmentation method that is based on the MC method, watershed transform, and the proposed size-weighted fuzzy clustering method. The conducted experiments demonstrate the strength of the proposed algorithm in segmenting small objects, which plays an important role in remote-sensing image segmentation applications. |
| Auteurs: Hasanzadeh, M.;Kasaei, S.; |
| Apparue dans: IEEE Geoscience and Remote Sensing Letters |
| Date publication: 07.-2010, volume: 7, issue:3, pages: 520 - 524 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A Narrow-Band Hairpin-Comb Two-Pole Filter With Source-Load Coupling |
Résumé:
The presented filter has two transmission poles and five transmission zeros. The mixed electric and magnetic coupling between two hairpin resonators, the tapped feeding position, and the source-load coupling configuration interacting on one another result in three transmission zeros in the vicinity of the passband. Two stubs added to the feeding lines contribute two additional transmission zeros beyond the passband. |
| Auteurs: Huan Wang;Qing-Xin Chu; |
| Apparue dans: IEEE Microwave and Wireless Components Letters |
| Date publication: 07.-2010, volume: 20, issue:7, pages: 372 - 374 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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|
| » A near-infrared optical fiber sensor for carbon monoxide concentration monitoring |
Résumé:
An optical fiber sensor presented is capable of monitoring the presence of carbon monoxide (CO) in the exhaust environment.Conventional gas sensor used to detect CO concentration is often difficult to achieve high sensitivity, selectivity, and specificity in presence of a mixture of gases. The design of this sensor using DFB LD as light source and low-cost near-infrared components, which make it suitable for using in an exhaust environment, is discussed. The sensor based on spectrum absorption principle is immune to corrosion and poison as it consists of glass and ceramic parts. By using differential construction, it can eliminate the influence of common mode interfering signals caused by the wave of LDs light intension, thermal zero shift, and zero shift of photoelectric device. A national instrument cRIO-9215 data acquisition card was used to acquire the output voltages and a LabView virtual instrument was used to store and process data. The response of the sensor to carbon dioxide supplied from the standard gas with dry nitrogen as a balancing gas in the laboratory was performed. The experimental results indicated that the sensor has been developed to operate within an exhaust environment and have high sensitivity and stability so it does not suffer from other gases interferences. The lower limit of detection for the sensor was found to be not less than 50 ppm for CO. This can be meeting the requirement of 100 ppm which is to be poisonous to human. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2192-2195, 2010; DOI 10.1002/mop.25469 |
| Auteurs: Shanying Zhu, Youping Chen, Gang Zhang, Jiming Sa |
| Apparue dans: Microwave and Optical Technology Letters |
| Date publication: 07.-2010 |
| Editeur: Wiley InterScience |
| Document complet vers site de l'éditeur |
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|
| » A Near-Optimal Algorithm Attacking the Topology Mismatch Problem in Unstructured Peer-to-Peer Networks |
Résumé:
In an unstructured peer-to-peer (P2P) network (e.g., Gnutella), participating peers choose their neighbors randomly such that the resultant P2P network mismatches its underlying physical network, resulting in the lengthy communication between the peers and redundant network traffics generated in the underlying network. Previous solutions to the topology mismatch problem in the literature either have no performance guarantees or are far from the optimum. In this paper, we propose a novel topology matching algorithm based on the Metropolis-Hastings method. Our proposal is guided by our insight analytical model and is close to the optimal design. Specifically, we show that our proposal constructs an unstructured P2P network in which a broadcast message, originated by any node v, reaches any other node u by taking approximately the only physical end-to-end delay between v and u. In addition, our design guarantees the exponential broadcast scope. We verify our solution through extensive simulations and show that our proposal considerably outperforms state-of-the-art solutions. |
| Auteurs: Hung-Chang Hsiao;Hao Liao;Po-Shen Yeh; |
| Apparue dans: IEEE Transactions on Parallel and Distributed Systems |
| Date publication: 07.-2010, volume: 21, issue:7, pages: 983 - 997 |
| Editeur: IEEE |
| Document complet vers site de l'éditeur |
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| » A neural network experiment on the site-specific simulation of potato tuber growth in Eastern Canada |
Résumé:
The objective of this work was to optimize a neural network (NN) for modelling potato tuber growth and its in-field variations in eastern Canada. In addition to climatic inputs, the cumulative and maximal leaf area index (LAI) were incorporated to account for in-field scale variability. Soil and genetic parameters were assumed to be integrated in LAI as suggested by earlier work. Each input and combination of inputs was evaluated from the changes they induced in MAE (mean absolute error) and RMSE (root mean square error). Results using data from several replicated on-farm experiments between 2005 and 2008 suggest that a... |
| Auteurs: Jérôme G., Fortin , François, Anctil , Léon-Étienne, Parent , Martin A., Bolinder |
| Apparue dans: Computers and Electronics in Agriculture |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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| » A new adaptive MAC protocol with QoS support based on IEEE 802.11 in ad hoc networks??? |
Résumé:
With the expanding of applications, the demand of quality of service (QoS) has become strongly increased in ad hoc networks. Since the efficient and reasonable MAC protocol is a key factor for providing QoS in ad hoc networks, in this paper we propose an adaptive QoS MAC protocol (AMP) based on IEEE 802.11. In AMP, we introduce the concept of transmission license, where only the node which holds transmission license can participate in the channel contention for changing the number of licenses according to the load of the network adaptively, controlling the number of the nodes that participate in the... |
| Auteurs: Rong, Geng , Lei, Guo , Xingwei, Wang |
| Apparue dans: Computers & Electrical Engineering |
| Date publication: 07.-2010 |
| Editeur: Elsevier B.V. |
| Document complet vers site de l'éditeur |
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