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Electrical and Electronics Engineering publications abstract of: 10-2010 sorted by title, page: 0
» 1/f Noise in GaN HEMTs grown under Ga-rich, N-rich, and NH3-rich conditions
Abstract:
The magnitude of the low-frequency 1/f noise in GaN/AlGaN HEMTs grown under Ga-rich, N-rich, and NH3-rich conditions varies in response to hot-electron stress. Density-functional-theory (DFT) calculations show that the Ga vacancies that are responsible for the positive shift in pinch-off voltage due to electrical stress in Ga-rich and N-rich devices do not contribute significantly to the observed changes in 1/f noise with electrical stress. The N anti-sites that cause negative shifts in pinch-off voltage in ammonia-rich devices can cause an increase in the noise magnitude after stress. DFT calculations also show that singly hydrogenated and dehydrogenated Ga-N divacancies also can...
Autors: Tania, Roy , Yevgeniy S., Puzyrev , En Xia, Zhang , Sandeepan, DasGupta , Sarah A., Francis , ...
Appeared in: Microelectronics Reliability
Publication date: Oct 2010
Publisher: Elsevier B.V.
 
» 100 Gb/s ETDM Transmitter Module
Abstract:
Components of a 100 Gb/s transmitter with electrical time-division multiplexing are presented as following: electrical multiplexer, driver amplifier, and large-bandwidth distributed feedback-traveling-wave electro-absorption modulator module. The performance of the parts of the transmitter, as well as the complete chain, is investigated for data operation and transmission in future 100 Gb/s Ethernet (100GbE). Clearly open eye diagrams at 100 Gb/s are demonstrated together with data transmission over 300 m long standard single mode fiber link.
Autors: Chaciński, M.;Westergren, U.;Stoltz, B.;Driad, R.;Makon, R. E.;Hurm, V.;Steffan, A. G.;
Appeared in: IEEE Journal of Selected Topics in Quantum Electronics
Publication date: Oct 2010, volume: 16, issue:5, pages: 1321 - 1327
Publisher: IEEE
 
» 2-D DoA Estimation with Cell Searching for a Mobile Relay Station with Uniform Circular Array
Abstract:
In this letter, a 2-D Direction-of-Arrival (DoA) estimation scheme with cell searching is proposed for a mobile relay station (MRS) with uniform circular array (UCA) at a handover region. The proposed scheme of cell searching and DoA estimation for the MRS with UCA is robust even when there exist symbol timing offsets (STOs). Compared with the previous scheme, the proposed scheme can reduce computational complexity and processing time for cell searching and DoA estimation. Simulation results are included to verify the performance of the proposed scheme under a mobile WiMAX environment.
Autors: Ko, Yo Han;Kim, Yeung Jun;Yoo, Hyun Il;Yang, Won Young;Cho, Yong Soo;
Appeared in: IEEE Transactions on Communications
Publication date: Oct 2010, volume: 58, issue:10, pages: 2805 - 2809
Publisher: IEEE
 
» 2-D Electrical Interferometer: A Novel High-Speed Quantizer
Abstract:
In this paper, we propose a 2-D electircal interferometer as a means of high-speed data conversion. The structure is based on wave propagation in 2-D lattices. We will discuss the principle behind this technique, which exploits wave propagation and medium manipulation in order to take advantage of different interference patterns. This method of quantization is based on passive lattices that can operate at very high frequencies on a conventional CMOS process. We analyze different properties of the structure and propose the design methodology. To show the feasibility of this approach, we design a 20-GS/s 4-bit quantizer consuming 194 mW for quanization and 943 mW for an analog memory. There is good agreement between analysis and simulation.
Autors: Tousi, Y. M.;Afshari, E.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2010, volume: 58, issue:10, pages: 2549 - 2561
Publisher: IEEE
 
» 20% Efficient Screen-Printed Cells With Spin-On-Dielectric-Passivated Boron Back-Surface Field
Abstract:
This paper reports on the characteristics of a spin-on dielectric which has been used as the rear-surface passivation layer to achieve 20% efficient screen-printed (SP) boron back-surface field (B-BSF) solar cells. The dielectric provides, in a single thermal step, both stable passivation of a heavily doped surface and strong gettering of iron which is a common contaminant in high-temperature boron diffusion processes. It was found that gettering of silicon substrates, contaminated during boron diffusion, is most effective when the dielectric is deposited on top of the boron-doped layer. The effect of dielectric charge density on passivation of surfaces was also studied and a very high charge density of was found to be necessary to significantly improve the passivation on surfaces with a boron concentration .
Autors: Das, A;Meemongkolkiat, V;Kim, D;Ramanathan, S;Rohatgi, A;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2010, volume: 57, issue:10, pages: 2462 - 2469
Publisher: IEEE
 
» 2010 WAMICON—Survey Says “Great Show” at This Year's East Coast Venue [Conference Report]
Abstract:
Autors: Culver, J.;Dunleavy, L.;Pengelly, R.;
Appeared in: IEEE Microwave Magazine
Publication date: Oct 2010, volume: 11, issue:6, pages: 132 - 134
Publisher: IEEE
 
» 258.16-259.95 GHz injection-locked frequency divider
Abstract:
A divide-by-2 injection-locked frequency divider (ILFD) using π-type LC networks is presented. This ILFD is fabricated in a 65 nm CMOS process. Its measured locking range is from 258.16 to 259.95 GHz with an input power of less than -25 dBm. Its power consumption is 3.9 mW from a 1.3 V supply excluding buffers and the bias current. Its area is 0.13 by 0.12 mm without pads.
Autors: Lee, I.-T.;Wang, C.-H.;Lin, B.-Y.;Liu, S.-I.;
Appeared in: Electronics Letters
Publication date: Oct 2010, volume: 46, issue:21, pages: 1438 - 1439
Publisher: IEEE
 
» 2PASS: Bandwidth-Optimized Location Cloaking for Anonymous Location-Based Services
Abstract:
Protection of users' location privacy is a critical issue for location-based services. Location cloaking has been proposed to blur users' accurate locations with cloaked regions. Although various cloaking algorithms have been studied, none of the prior work has explored the impact of cloaking on the bandwidth usage of requested services. In this paper, we develop an innovative result-aware location cloaking approach, called 2PASS. Based on the notion of Voronoi cells, 2PASS minimizes the number of objects to request, and hence, the bandwidth while meeting the same privacy requirement. The core component of 2PASS is a lightweight WAG-tree index, based on which efficient and secure client and server procedures are designed. Through threat analysis and experimental results, we argue that 2PASS is robust and outperforms state-of-the-art approaches in terms of various metrics, such as query response time and bandwidth consumption. We also enclose a case study of 2PASS in a real-life application.
Autors: Haibo Hu;Jianliang Xu;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Oct 2010, volume: 21, issue:10, pages: 1458 - 1472
Publisher: IEEE
 
» 3-D Scalable Medical Image Compression With Optimized Volume of Interest Coding
Abstract:
We present a novel 3-D scalable compression method for medical images with optimized volume of interest (VOI) coding. The method is presented within the framework of interactive telemedicine applications, where different remote clients may access the compressed 3-D medical imaging data stored on a central server and request the transmission of different VOIs from an initial lossy to a final lossless representation. The method employs the 3-D integer wavelet transform and a modified EBCOT with 3-D contexts to create a scalable bit-stream. Optimized VOI coding is attained by an optimization technique that reorders the output bit-stream after encoding, so that those bits belonging to a VOI are decoded at the highest quality possible at any bit-rate, while allowing for the decoding of background information with peripherally increasing quality around the VOI. The bit-stream reordering procedure is based on a weighting model that incorporates the position of the VOI and the mean energy of the wavelet coefficients. The background information with peripherally increasing quality around the VOI allows for placement of the VOI into the context of the 3-D image. Performance evaluations based on real 3-D medical imaging data showed that the proposed method achieves a higher reconstruction quality, in terms of the peak signal-to-noise ratio, than that achieved by 3D-JPEG2000 with VOI coding, when using the MAXSHIFT and general scaling-based methods.
Autors: Sanchez, V.;Abugharbieh, R.;Nasiopoulos, P.;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Oct 2010, volume: 29, issue:10, pages: 1808 - 1820
Publisher: IEEE
 
» 3-D Target-Based Distributed Smart Camera Network Localization
Abstract:
For distributed smart camera networks to perform vision-based tasks such as subject recognition and tracking, every camera's position and orientation relative to a single 3-D coordinate frame must be accurately determined. In this paper, we present a new camera network localization solution that requires successively showing a 3-D feature point-rich target to all cameras, then using the known geometry of a 3-D target, cameras estimate and decompose projection matrices to compute their position and orientation relative to the coordinatization of the 3-D target's feature points. As each 3-D target position establishes a distinct coordinate frame, cameras that view more than one 3-D target position compute translations and rotations relating different positions' coordinate frames and share the transform data with neighbors to facilitate realignment of all cameras to a single coordinate frame. Compared to other localization solutions that use opportunistically found visual data, our solution is more suitable to battery-powered, processing-constrained camera networks because it requires communication only to determine simultaneous target viewings and for passing transform data. Additionally, our solution requires only pairwise view overlaps of sufficient size to see the 3-D target and detect its feature points, while also giving camera positions in meaningful units. We evaluate our algorithm in both real and simulated smart camera networks. In the real network, position error is less than 1 when the 3-D target's feature points fill only 2.9% of the frame area.
Autors: Kassebaum, J.;Bulusu, N.;Feng, W.-C.;
Appeared in: IEEE Transactions on Image Processing
Publication date: Oct 2010, volume: 19, issue:10, pages: 2530 - 2539
Publisher: IEEE
 
» 33–43 GHz and 66–86 GHz VCO With High Output Power in an 80 GHz SiGe HBT Technology
Abstract:
This letter presents a signal generation circuit that combines a wide tuning range voltage controlled oscillator (VCO) and a frequency doubler. The VCO provides two differential outputs with different power levels. A push-push frequency doubler is designed and cascaded to the high power output of the VCO, while the low power output is reserved to drive a frequency divider in a PLL. The VCO can be tuned from 33 to 43 GHz, with around 0 dBm output power at the low power output. Simultaneously, signal generation from 66 to 86 GHz is achieved at the doubler output, with a maximum output power of 1.1 dBm at 74 GHz ( 2.5 dBm at 81 GHz). The measured phase noise at the VCO output and the doubler output are 91 dBc/Hz and 83 dBc/Hz at 1 MHz offset ( 112 dBc/Hz and 106 dBc/Hz at 10 MHz offset), respectively. The circuit is realized in a 0.8 SiGe heterojunction bipolar transistor process, with of 80/90 GHz. The VCO consumes 81 mA current while the doubler consumes an extra 17 mA from a 4 V supply. The circuit demonstrates the possibility of wide-band signal generation up to with sufficient output power (e.g. to drive a mixer) in a conservatively scaled, low-cost process.
Autors: Liu, G.;Trasser, A.;Schumacher, H.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2010, volume: 20, issue:10, pages: 557 - 559
Publisher: IEEE
 
» 3D Holographic Imaging and Trapping for Non-Invasive Cell Identification and Tracking
Abstract:
Real-time high-throughput identification, screening, characterization, and processing of biological specimen is of great interest to a host of areas spanning from cell biology and medicine to security and defense. Much like human biometrics, microorganisms exhibit natural signatures that can be used for identification. In this paper, we first overview two optical techniques, namely digital holographic microscopy and holographic optical tweezers which can non-invasively image, manipulate, and identify microorganisms in three dimensions. The two methods bear similarities in their optics and implementation. Thus, we have proposed a new approach to identification of micro/nano organisms and cells by combining the two methods of digital holographic microscopy and holographic optical tweezers which can be integrated into a single compact hardware. The proposed system can simultaneously sense, control, identify, and track cells and microorganisms in three dimensions. New possibilities that arise from the proposed method are discussed.
Autors: DaneshPanah, M.;Zwick, S.;Schaal, F.;Warber, M.;Javidi, B.;Osten, W.;
Appeared in: Journal of Display Technology
Publication date: Oct 2010, volume: 6, issue:10, pages: 490 - 499
Publisher: IEEE
 
» 3D volumetric modeling of grapevine biomass using Tripod LiDAR
Abstract:
 Research highlights: ? Vine wood volume derived from laser scanning is compared with analog measurements. ? Correlation between the two methods ranged between 0.73 and 0.97. ? Laser scanning yields a linear relationship between vine volume and tissue mass. ? TLS allows accurate volume measurements, no destructive harvest, automated processing.

Autors: Tripod mounted laser scanning provides the means to generate high-resolution volumetric measures of vegetation structure and perennial woody tissue for the calculation of standing biomass in agronomic and natural ecosystems. Other than costly destruc
Appeared in: Computers and Electronics in Agriculture
Publication date: Oct 2010
Publisher: Elsevier B.V.
 
» 4-D x 3-D ultrasound: real-time scan conversion, filtering, and display of displacement vectors with a motorized curvilinear transducer
Abstract:
Recent research in the field of elastography has sought to expand displacement tracking to three dimensions. Once the 3-D volumes of displacement data have been obtained, they must be scan converted so that further processing, such as inversion methods to obtain tissue elasticity, can take place in Cartesian coordinates. This paper details an efficient and geometrically accurate algorithm to scan convert 3-D volumes of displacement vectors obtained from a motorized sector transducer. The proposed algorithm utilizes the physical scan geometry to convert the 3-D volumes of displacement data to both Cartesian coordinates and Cartesian displacements. Spatially varying filters are also proposed to prevent aliasing while minimizing data loss. Validation of the system has shown the algorithm to be correct to floating point precision, and the 3-D scan conversion and filtering can be performed faster than the native rate of data acquisition for the motorized transducer.
Autors: Pospisil, E.R.;Rohling, R.;Azar, R.Z.;Salcudean, S.E.;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Oct 2010, volume: 57, issue:10, pages: 2271 - 2283
Publisher: IEEE
 
» 400-GHz InP/GaAsSb DHBTs With Low-Noise Microwave Performance
Abstract:
We report self-aligned 0.3- emitter InP/GaAsSb/InP DHBTs featuring a common–emitter current gain of 46 and cutoff frequencies and for devices implemented with a 20-nm C-doped base and a 75-nm InP collector. Our DHBTs display attractive noise properties with a minimum noise figure at 20 GHz, which is nearly independent of frequency over the 2–20-GHz measurement band. This represents an improvement of at least 2.3 dB with respect to previously published results for GaAsSb-based devices, due to process improvements that allow good RF characteristics to be maintained at the low current levels required for low noise operation. Analysis shows that the low-frequency is limited by the relatively low current gain values typical of III–V HBTs. InP/GaAsSb DHBTs could be attractive low-noise devices for higher frequencies.
Autors: Zeng, Y.;Ostinelli, O.;Lovblom, R.;Alt, A. R.;Benedickter, H.;Bolognesi, C. R.;
Appeared in: IEEE Electron Device Letters
Publication date: Oct 2010, volume: 31, issue:10, pages: 1122 - 1124
Publisher: IEEE
 
» 5-bit MEMS distributed phase shifter
Abstract:
An X-band 5-bit MEMS distributed phase shifter with a total area of 19.110 x 2.646 mm2 is presented. Based on the equivalent-circuit model, a novel design method is applied to design the phase shifter. The basis of the method is to optimise the length of the MEMS device while maintaining a certain return loss. The fabricated phase shifter shows average measured insertion loss of -1.54 dB, return loss of -12.12 dB, and relative phase error of 2.41% for 32 unique phase states at 10 GHz. The MEMS bridge using serpentine flexures is actuated with an actuation voltage of 15 V.
Autors: Du, Y.;Bao, J.;Zhao, X.;
Appeared in: Electronics Letters
Publication date: Oct 2010, volume: 46, issue:21, pages: 1452 - 1453
Publisher: IEEE
 
» 5/10-Gb/s Burst-Mode Clock and Data Recovery Based on Semiblind Oversampling for PONs: Theoretical and Experimental
Abstract:
In this paper, we demonstrate a 5/10-Gb/s burst-mode clock and data recovery circuit (BM-CDR) for passive optical network (PON) applications. The BM-CDR is based on a phase-tracking oversampling (semiblind) CDR circuit operated at twice the bit rate and a clock phase aligner that makes use of a simple phase-picking algorithm for automatic clock phase acquisition. The design provides low latency and fast response without requiring a reset signal from the network layer. We experimentally test the proposed BM-CDR in a 20-km PON uplink. The BM-CDR achieves a bit error rate (BER) and packet loss ratio (PLR) while featuring: 1) instantaneous (0 preamble bit) phase acquisition for any phase step ( rad) between successive bursts; 2) BER and PLR sensitivities of 24.2 and 25.4 dBm, respectively; 3) negligible burst-mode sensitivity penalty of 0.8 dB; 4) frequency acquisition range of 242 MHz; 5) consecutive identical digit (CID) immunity of 3100 bits; and 6) dynamic range of 3 dB. With the instantaneous phase acquisition, we predict the physical efficiency of the upstream PON traffic to be 99%. We also present a unified probabilistic theory for conventional CDRs, times oversampling CDRs in either time or space, and BM-CDRs built from oversampling CDRs. This theory can quantitatively explain the performance of these circuits in terms of the BER and PLR. The theoretical model accounts for the following parameters: 1) silence period, including phase step and CIDs, between consecutive packets; 2) finite frequency offset between the sam- - pling clock and data rate; 3) preamble length; 4) jitter on the sampling clock; and 5) pattern correlator error resistance. On the basis of this theory, we perform a comprehensive theoretical analysis to assess the tradeoffs between these parameters, and compare the results experimentally to validate the theoretical model.
Autors: Shastri, B. J.;Plant, D. V.;
Appeared in: IEEE Journal of Selected Topics in Quantum Electronics
Publication date: Oct 2010, volume: 16, issue:5, pages: 1298 - 1320
Publisher: IEEE
 
» 8T vs. 6T SRAM cell radiation robustness: A comparative analysis
Abstract:
We analyze and compare the impact of radiation-induced transient effects based on evaluating the critical charge parameter for 6T and 8T SRAMs during hold, read and write operations. Results on a commercial 65nm CMOS technology show that 6T and 8T cells offer quite similar robustness when they are in hold. However, the critical charge observed in other operation modes is reduced a 55% respect to the hold operation. For this reason, we provide a thorough analysis of the critical charge behavior in 6T and 8T SRAMs to determine the dependence of memory radiation robustness with memory state. Single event upsets...
Autors: Bartomeu, Alorda , Gabriel, Torrens , Sebastià, Bota , Jaume, Segura
Appeared in: Microelectronics Reliability
Publication date: Oct 2010
Publisher: Elsevier B.V.
 
» Zeff measurement using extreme ultraviolet bremsstrahlung emission in LHD
Abstract:
Radial profile measurement of Zeff using visible bremsstrahlung (5300 Å) in the Large Helical Device (LHD) has often encountered difficulties because the intensity profile was largely deformed by the nonuniform visible bremsstrahlung emissions from the edge ergodic layer surrounding the core plasma. A space-resolved flat-field extreme ultraviolet (EUV) spectrometer has been newly adopted to measure the Zeff profile using the EUV bremsstrahlung continuum in the wavelength range of 70–75 Å. The EUV bremsstrahlung intensity profiles have been measured and checked for all the magnetic configurations with totally different magnetic field structures in the ergodic layer of LHD. It is found that the nonuniform bremsstrahlung emission from the thick ergodic layer can be entirely eliminated by use of the EUV emission with relatively high photon energy of 170 eV. As a result, the Zeff profile can be successfully measured for most of discharges regardless of magnetic field structures of the ergodic layer. The Zeff profiles measured in the EUV range are compared with those measured in the visible range at a magnetic configuration with the thinnest ergodic layer thickness. The result verifies that the use of the EUV bremsstrahlung continuum is an alternative way for the Zeff measurement in toroidal plasmas with nonuniform bremsstrahlung emissions at the edge. Typical results from the EUV bremsstrahlung measurement are presented showing a fairly flat Zeff profile with error bars of ±14%.
Autors: Zhou, Hangyu;Morita, Shigeru;Goto, Motoshi;Dong, Chunfeng;Yanagibayashi, Jun;Hasuo, Masahiro;
Appeared in: Review of Scientific Instruments
Publication date: Oct 2010, volume: 81, issue:10, pages: 10D706 - 10D706-4
Publisher: IEEE
 
» K-line spectra from tungsten heated by an intense pulsed electron beam
Abstract:
The plasma-filled rod-pinch diode (PFRP) is an intense source of x-rays ideal for radiography of dense objects. In the PRFP megavoltage electrons from a pulsed discharge concentrate at the pointed end of a 1 mm diameter tapered tungsten rod. Ionization of this plasma might increase the energy of tungsten’s 1 fluorescence line, at 59.3182 keV, enough for the difference to be observed by a high-resolution Cauchois transmission crystal spectrograph. When the PFRP’s intense hard bremsstrahlung is suppressed by the proper shielding, such an instrument gives excellent fluorescence spectra, albeit with as yet insufficient resolution to see any effect of tungsten’s ionization. Higher resolution is possible with various straightforward upgrades that are feasible thanks to the radiation’s high intensity.
Autors: Pereira, N. R.;Weber, B. V.;Apruzese, J. P.;Mosher, D.;Schumer, J. W.;Seely, J. F.;Szabo, C. I.;Boyer, C. N.;Stephanakis, S. J.;Hudson, L. T.;
Appeared in: Review of Scientific Instruments
Publication date: Oct 2010, volume: 81, issue:10, pages: 10E302 - 10E302-5
Publisher: IEEE
 
» Positive Filtering for Positive Linear Discrete-Time Systems: An Augmentation Approach
Abstract:
In this note, we address the reduced-order positive filtering problem of positive discrete-time systems under the performance. Commonly employed approaches, such as linear transformation and elimination technique, may not be applicable in general due to the positivity constraint of the filter. To cope with the difficulty, we first represent the filtering error system as a singular system by means of the system augmentation approach, which will facilitate the consideration of the positivity constraint. Two necessary and sufficient conditions are obtained in terms of matrix inequalities under which the filtering error system has a prescribed performance. Then, a necessary and sufficient condition is proposed for the existence of the desired positive filters, and an iterative linear matrix inequality (LMI) algorithm is presented to compute the filtering matrices, which can be easily checked by standard software. Finally, a numerical example to illustrate the effectiveness of the proposed design procedures is presented.
Autors: Li, P.;Lam, J.;Shu, Z.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Oct 2010, volume: 55, issue:10, pages: 2337 - 2342
Publisher: IEEE
 
» State-Feedback-Control Design for Discrete-Time Fuzzy Systems Using Relaxation Technique for Parameterized LMI
Abstract:
In this study, we establish a less-conservative stabilization condition for a class of discrete-time Takagi–Sugeno (T–S) fuzzy systems. To this end, we propose a useful relaxation technique that can be used to transform parameterized-linear-matrix inequalities (PLMIs) with homogeneous polynomial dependence on current-time parameters and preceding parameters into a finite set of LMIs. The main feature of this technique is that all possible slack variables can be included in the relaxation process to fully exploit the convexity of the PLMIs. By applying the relaxation technique, we establish a less-conservative LMI-based stabilization condition.
Autors: Kim, S. H.;Park, P.;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Oct 2010, volume: 18, issue:5, pages: 985 - 993
Publisher: IEEE
 
» A 0.25 m InP DHBT 200 GHz+ Static Frequency Divider
Abstract:
Static frequency dividers are widely used technology performance benchmark circuits. Using a 0.25 530 GHz /600 GHz+ InP DHBT process, a static frequency divider circuit has been designed, fabricated, and measured to operate up to 200.6 GHz . The divide-by-two core flip-flop dissipates 228 mW. Techniques used for the divider design optimization and for selecting variants to maximize performance across process changes are also discussed.
Autors: D'Amore, M.;Monier, C.;Lin, S. T.;Oyama, B.;Scott, D. W.;Kaneshiro, E. N.;Chang, P.-C.;Sato, K. F.;Niemi, A.;Dang, L.;Cavus, A.;Gutierrez-Aitken, A.;Oki, A. K.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 1992 - 2002
Publisher: IEEE
 
» A 1–25 GHz GaN HEMT MMIC Low-Noise Amplifier
Abstract:
This letter presents an ultra-wideband low noise amplifier (LNA) using gallium-nitride (GaN) high-electron mobility transistors (HEMT) technology. A bandwidth of 1–25 GHz with 13 dB peak power gain is achieved using a modified resistive-feedback topology. To obtain such a wide bandwidth, several bandwidth enhancement techniques are utilized. An inductor connected to the source of the input transistor ensures good input matching ( ) across the entire bandwidth. The shunt feedback loop and the inductive source degeneration minimize all the required inductor values. This GaN HEMT LNA is believed to have the widest bandwidth among all GaN HEMT monolithic microwave integrated circuit (MMIC) LNAs reported to date. With 3.3 dB minimum noise figure (F), 33.5 dBm maximum output-referred third-order intercept point (OIP3), 20 dBm maximum output-referred 1 dB compression point (Output P1 dB), this MMIC amplifier is comparable in performance to distributed amplifiers (DAs) but with significantly lower power consumption and smaller area.
Autors: Chen, M.;Sutton, W.;Smorchkova, I.;Heying, B.;Luo, W.-B.;Gambin, V.;Oshita, F.;Tsai, R.;Wojtowicz, M.;Kagiwada, R.;Oki, A.;Lin, J.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2010, volume: 20, issue:10, pages: 563 - 565
Publisher: IEEE
 
» A 120–145 GHz Heterodyne Receiver Chipset Utilizing the 140 GHz Atmospheric Window for Passive Millimeter-Wave Imaging Applications
Abstract:
For passive mm-wave imaging applications, broadband mm-wave receivers functioning within atmospheric windows are highly desired. Within this paper, a heterodyne receiver chipset utilizing the 140 GHz atmospheric window is presented. The heterodyne chipset is based on two different millimeter-wave monolithic integrated circuits (MIMICs). One is the receiver MIMIC including a low-noise amplifier, a down-conversion mixer, a frequency multiplier and a local oscillator buffer amplifier together with a local oscillator distribution network. The other is a voltage-controlled oscillator (VCO) working in the 35 GHz frequency range to generate the local oscillator signal for the receiver (down-converter) chip. The process technology chosen to realize the chipset is a 100 nm gatelength metamorphic InAlAs/InGaAs high electron mobility transistor (HEMT) technology on 50 m thick and 4 inch diameter GaAs substrates. The chips are utilizing a grounded coplanar waveguide (GCPW) technology. For an operation frequency band from 120 to 145 GHz, the receiver demonstrates a flat conversion gain between 1 and 2 dB with a power consumption of 120 mW. The VCO is tuneable from 31 to 37 GHz with associated output power levels from 2 to 1 dBm. Detailed descriptions of the individual building blocks are given and measured results are presented for the building blocks as well as for the receiver.
Autors: Koch, S.;Guthoerl, M.;Kallfass, I.;Leuther, A.;Saito, S.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 1961 - 1967
Publisher: IEEE
 
» A 130 point Nd:YAG Thomson scattering diagnostic on MAST
Abstract:
A Thomson scattering diagnostic designed to measure both edge and core physics has been implemented on MAST. The system uses eight Nd:YAG lasers, each with a repetition rate of 30 Hz. The relative and absolute timing of the lasers may be set arbitrarily to produce fast bursts of measurements to suit the time evolution of the physics being studied. The scattered light is collected at F/6 by a 100 kg six element lens system with an aperture stop of 290 mm. The collected light is then transferred to 130 polychromators by 130 independent fiber bundles. The data acquisition and processing are based on a distributed computer system of dual core processors embedded in 26 chassis. Each chassis is standalone and performs data acquisition and processing for five polychromators. This system allows data to be available quickly after the MAST shot and has potential for real-time operations.
Autors: Scannell, R.;Walsh, M. J.;Dunstan, M. R.;Figueiredo, J.;Naylor, G.;OGorman, T.;Shibaev, S.;Gibson, K. J.;Wilson, H.;
Appeared in: Review of Scientific Instruments
Publication date: Oct 2010, volume: 81, issue:10, pages: 10D520 - 10D520-4
Publisher: IEEE
 
» A 140 dB-CMRR Current-Feedback Instrumentation Amplifier Employing Ping-Pong Auto-Zeroing and Chopping
Abstract:
This paper presents a precision general-purpose current-feedback instrumentation amplifier (CFIA) that employs a combination of ping-pong auto-zeroing and chopping to cancel its offset and noise. A comparison of offset-cancellation techniques shows that neither chopping nor auto-zeroing is an ideal solution for general-purpose CFIAs, since chopping results in output ripple, and auto-zeroing is associated with increased low-frequency noise. The presented CFIA mitigates these unintended side effects through a combination of these techniques. A ping-pong auto-zeroed input stage with slow-settling offset-nulling loops is applied to limit the bandwidth of the increased noise to less than half of the auto-zeroing frequency. This noise is then modulated away from DC by chopping the input stage at half the auto-zeroing frequency, reducing the low-frequency noise to the 27 nV/ white-noise level, without introducing extra output ripple. The auto-zeroing is augmented with settling phases to further reduce output transients. The CFIA was realized in a 0.5 m analog CMOS process and achieves a typical offset of 2.8 V and a CMRR of 140 dB in a common-mode voltage range that includes the negative supply.
Autors: Pertijs, M. A. P.;Kindt, W. J.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2044 - 2056
Publisher: IEEE
 
» A 2.6 mW 6 bit 2.2 GS/s Fully Dynamic Pipeline ADC in 40 nm Digital CMOS
Abstract:
A 2.2 GS/s 4 -interleaved 6b ADC in 40 nm digital CMOS is presented. Each ADC slice consists of a 1b folding stage followed by a pipelined binary-search sub-ADC using dynamic nonlinear amplifiers for low power consumption and high speed. The folding stage samples the input, removes its common-mode component and rectifies the differential voltage. The pipelined binary-search sub-ADC leverages threshold calibration to correct for amplifier and comparator imperfections, which allows the use of inherently nonlinear dynamic amplifiers. The prototype achieves 31.6 dB SNDR at 2.2 GS/s with a 2 GHz ERBW for 2.6 mW power consumption in an area of 0.03 .
Autors: Verbruggen, B.;Craninckx, J.;Kuijk, M.;Wambacq, P.;Van der Plas, G.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2080 - 2090
Publisher: IEEE
 
» A 20-GS/s 5-b SiGe ADC for 40-Gb/s Coherent Optical Links
Abstract:
A 10-GBd 40-Gb/s coherent optical transport is a promising technology for higher data rate communications by virtue of improved sensitivity and high spectrum efficiency. One of the major challenges in designing a 40-Gb/s coherent quadrature-phase-shift-keying receiver is to achieve high-speed data conversion at around 20-GHz sampling rate with at least 5-bit resolution. With the detailed design framework for the target requirements, this paper presents a 5-bit 20-GS/s flash analog-to-digital converter (ADC) realized in 0.18- SiGe BiCMOS technology. The ADC includes a track-and-hold amplifier (THA) incorporated with linear distortion compensation, double-interpolation preamplifier, current bias-weighted comparator, and high-speed encoder logic. At 4 V, the THA had a bandwidth that exceeded 23 GHz and an IIP3 of 24 dBm. The ADC achieves a signal-to-noise-plus-distortion ratio of 28.6 dB and a spurious-free dynamic range of 36 dB with a 1-GHz input sinusoid sampled at 20 GS/s. The ADC has a wide resolution bandwidth of 7 GHz, and the figure of merit is 9.54 pJ/conversion-step. The ADC consumes 3.24 W from 4- and 3-V supplies when sampled at 20 GHz. The prototype ADC occupies 8.68 of silicon area.
Autors: Lee, J.;Weiner, J.;Chen, Y.-K.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Oct 2010, volume: 57, issue:10, pages: 2665 - 2674
Publisher: IEEE
 
» A 2 2 Split Cross-Bar Optical Switch Using a Hybrid Actuation Configuration
Abstract:
In this paper, a 2 2 split cross-bar optical switch which employs a hybrid actuation configuration is presented. The main advantages of this proposed switch include low actuation voltage, low power consumption, and easy fiber alignment. This optical switch consists of a micromachined micro-mirror structure and a mini-actuator module. The micro-mirror structure, which comprises two movable vertical mirrors with cantilevers, two fixed vertical mirrors, and light-path trenches, is realized by using a simple KOH silicon etching process. The mini-actuator module, which includes two commercially-available electromagnetic bistable actuators attached with L-shaped arms, is used to actuate micro-mirrors. The measured insertion losses of the proposed switch is between dB, the cross-talk is about dB, and the switching time is less than 13 ms. The long-term reliability test of the SCB switch is performed by continuously actuating the device for 10 000 cycles at 1 Hz, and the deviation of the measured insertion loss is less than 0.05 dB.
Autors: Liao, B.-T.;Chia, B. T.;Shih, S.-C.;Fan, K.-C.;Yang, Y.-J. J.;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2010, volume: 28, issue:20, pages: 2905 - 2911
Publisher: IEEE
 
» A 2 2 Split Cross-Bar Optical Switch Using a Hybrid Actuation Configuration
Abstract:
In this paper, a 2 2 split cross-bar optical switch which employs a hybrid actuation configuration is presented. The main advantages of this proposed switch include low actuation voltage, low power consumption, and easy fiber alignment. This optical switch consists of a micromachined micro-mirror structure and a mini-actuator module. The micro-mirror structure, which comprises two movable vertical mirrors with cantilevers, two fixed vertical mirrors, and light-path trenches, is realized by using a simple KOH silicon etching process. The mini-actuator module, which includes two commercially-available electromagnetic bistable actuators attached with L-shaped arms, is used to actuate micro-mirrors. The measured insertion losses of the proposed switch is between dB, the cross-talk is about dB, and the switching time is less than 13 ms. The long-term reliability test of the SCB switch is performed by continuously actuating the device for 10 000 cycles at 1 Hz, and the deviation of the measured insertion loss is less than 0.05 dB.
Autors: Liao, B.-T.;Chia, B. T.;Shih, S.-C.;Fan, K.-C.;Yang, Y.-J. J.;
Appeared in: Journal of Lightwave Technology
Publication date: Oct 2010, volume: 28, issue:20, pages: 2905 - 2911
Publisher: IEEE
 
» A 3 Watt 39.8–44.6 Gb/s Dual-Mode SFI5.2 SerDes Chip Set in 65 nm CMOS
Abstract:
A Dual-mode 2 21.5–22.3 Gb/s DQPSK or 1 39.8–44.6 Gb/s NRZ to 4 9.95–11.2 Gb/s SFI5.2-compliant two-chip SerDes for a family of 40 Gb/s optical transponders has been fabricated in 65 nm 12-metal CMOS. By demultiplexing to 16 2.5 Gb/s internally, all logic and testability functions could be implemented in standard-cell CMOS, resulting in total power consumption of 3 W, 75% lower than commercial BiCMOS SFI5 40 Gb/s SerDes ICs. Chip area is 4 4 mm, and the ICs are flip-chip mounted into a quad flat-pack package.
Autors: Nedovic, N.;Kristensson, A.;Parikh, S.;Reddy, S.;McLeod, S.;Tzartzanis, N.;Kanda, K.;Yamamoto, T.;Matsubara, S.;Kibune, M.;Doi, Y.;Ide, S.;Tsunoda, Y.;Yamabana, T.;Shibasaki, T.;Tomita, Y.;Hamada, T.;Sugawara, M.;Ikeuchi, T.;Kuwata, N.;Tamura, H.;Oga
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2016 - 2029
Publisher: IEEE
 
» A 3-D Audio-Visual Corpus of Affective Communication
Abstract:
Communication between humans deeply relies on the capability of expressing and recognizing feelings. For this reason, research on human-machine interaction needs to focus on the recognition and simulation of emotional states, prerequisite of which is the collection of affective corpora. Currently available datasets still represent a bottleneck for the difficulties arising during the acquisition and labeling of affective data. In this work, we present a new audio-visual corpus for possibly the two most important modalities used by humans to communicate their emotional states, namely speech and facial expression in the form of dense dynamic 3-D face geometries. We acquire high-quality data by working in a controlled environment and resort to video clips to induce affective states. The annotation of the speech signal includes: transcription of the corpus text into the phonological representation, accurate phone segmentation, fundamental frequency extraction, and signal intensity estimation of the speech signals. We employ a real-time 3-D scanner to acquire dense dynamic facial geometries and track the faces throughout the sequences, achieving full spatial and temporal correspondences. The corpus is a valuable tool for applications like affective visual speech synthesis or view-independent facial expression recognition.
Autors: Fanelli, G.;Gall, J.;Romsdorfer, H.;Weise, T.;Van Gool, L.;
Appeared in: IEEE Transactions on Multimedia
Publication date: Oct 2010, volume: 12, issue:6, pages: 591 - 598
Publisher: IEEE
 
» A 3-GHz Serial ATA Spread-Spectrum Clock Generator Employing a Chaotic PAM Modulation
Abstract:
In this paper, we propose a prototype of a spread-spectrum clock generator which is the first known specifically meant generator for 3-GHz Serial Advanced Technology Attachment II (SATA-II) applications. A further innovative aspect of our prototype is that it takes advantage of a chaotic pulse-amplitude modulation as driving signal, instead of a triangular signal as in all spread-spectrum generators proposed so far in the literature for SATA-II. In this way, we are able to obtain the optimal theoretical electromagnetic-interference reduction by avoiding the periodicity of the modulated clock and completely flattening the peaks in the power spectral density. We also show that, despite the fact that such an unconventional aperiodic modulating signal is used, the clock can be recovered by exploiting a standard clock and data recovery circuit at the receiver side of the SATA-II bus. The circuit prototype has been implemented in 0.13- CMOS technology and achieves a peak reduction greater than 14 dB measured at , which is better than any other prototypes presented in the literature. The estimated random jitter is 5.4 , while the chip active area is and the power consumption is as low as 14.7 mW.
Autors: Pareschi, F.;Setti, G.;Rovatti, R.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Oct 2010, volume: 57, issue:10, pages: 2577 - 2587
Publisher: IEEE
 
» A 5.5-mW 9.4-dBm IIP3 1.8-dB NF CMOS LNA Employing Multiple Gated Transistors With Capacitance Desensitization
Abstract:
A capacitance desensitization technique is proposed for a multiple gated transistors amplifier with source degeneration to relax second-order distortion contribution to a third-order intermodulation distortion (IMD3), as well as an induced-gate noise contribution to noise figure. An extra capacitance, which is added between gate and source nodes of input transistors in a parallel manner, can desensitize the contribution of second-order harmonic feedback to IMD3. The capacitance is useful for optimizing noise figure, as well by controlling the input matching network quality factor ( ), which can desensitize the induced-gate noise contribution to noise figure. The low-noise amplifier is implemented with the proposed technique using 1P6M 0.18- m CMOS technology for 900-MHz code division multiple access (CDMA) receivers. It shows a third-order intercept point of 9.4 dBm and noise figure of 1.8 dB while consuming 5.5 mW at 1.5 V.
Autors: Jin, T. H.;Kim, T. W.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2010, volume: 58, issue:10, pages: 2529 - 2537
Publisher: IEEE
 
» A 6.4 Gbit/s Embedded Compression Codec for Memory-Efficient Applications on Advanced-HD Specification
Abstract:
The embedded compression (EC) technique is applied to reduce the memory bandwidth and capacity in a display system. In this paper, the high-speed EC algorithm is proposed for advanced-HD specification. It mainly comprises three features: 1) the associated geometric-based probability model is developed to construct context-modeling mechanism without context-table; 2) develop content-adaptive Golomb-Rice code and geometric-based binary code as the entropy coding with minor order of context; and 3) provide the rate control mechanism to guarantee the saving ratio of memory bandwidth and capacity. With competitive coding efficiency, the computation-efficiency of the proposed EC algorithm is about 44% and 40% of FELICS and JPEG-LS. The proposed very-large-scale integration architecture of entire codec is implemented in TSMC 0.18- 1P6M CMOS technology. Based on pixel-based parallelism and segment-based parallelism techniques, the encoding/decoding capability reaches Quad Full-high definition (QFHD) (3840 2160) at 30 Hz. The maximum throughput is as high as 6.4 Gbit/s. Furthermore, with multi-level parallelism, the performance can be extended to QHD (2560 1440) at 120 Hz and QFHD at 120 Hz for the double frame rate technique.
Autors: Tsai, T.-H.;Lee, Y.-H.;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2010, volume: 20, issue:10, pages: 1277 - 1291
Publisher: IEEE
 
» A 60 GHz Injection-Locked Frequency Tripler With Spur Suppression
Abstract:
A 60 GHz injection-locked frequency tripler is designed to improve spectral purity with spur suppression of the fundamental and the even-order harmonics. Several circuit designs are utilized in the harmonic current injection circuit to maximize the third-order harmonic and minimize the undesired harmonic current outputs, including notch filters and a capacitive cross-coupled transistor pair. With the input signal of 0.5 dBm at 19.7 GHz, the harmonic rejection ratios of the fundamental, and the second-order achieve 31.3 dBc, and 45.8 dBc, respectively. Implemented in 0.13 m CMOS technology, the core circuit consumes power of 9.96 mW with 1.2 V supply voltage. The entire die occupies an area of 985 866 m
Autors: Kuo, C.-N.;Yan, T.-C.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Oct 2010, volume: 20, issue:10, pages: 560 - 562
Publisher: IEEE
 
» A 86 MHz–12 GHz Digital-Intensive PLL for Software-Defined Radios, Using a 6 fJ/Step TDC in 40 nm Digital CMOS
Abstract:
A 86 MHz–12 GHz digital-intensive reconfigurable PLL frequency synthesizer is presented with 100 kHz to 2 MHz bandwidth. It leverages a 6 fJ/step 5.5 ps, 14b coarse–fine TDC and a 6–12 GHz dual-VCO set. Several simple calibration schemes are proposed that enable the proper performance of the highly efficient TDC in the PLL. The 0.28 synthesizer, which is appropriate for use in a Software-Defined Radio, features noise cancellation and digital phase modulation and consumes less than 30 mW.
Autors: Borremans, J.;Vengattaramane, K.;Giannini, V.;Debaillie, B.;Van Thillo, W.;Craninckx, J.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2116 - 2129
Publisher: IEEE
 
» A 9 A, Addressable Gen2 Sensor Tag for Biosignal Acquisition
Abstract:
Biosensors present exciting opportunities in novel medical and scientific applications. However, sensor tags presented to date cannot interface with practical sensors, lack addressability, and/or require a custom (high-cost) interrogator. Our tag provides these features via ultra-low-power circuitry including a low-noise biosignal amplifier, unique tag ID generator, calibration-free 3 MHz oscillator, and EPC C1 Gen2 protocol compatibility. In addition to design details and measurement data from the fabricated IC, we present in vivo muscle temperature measurement from an untethered in-flight hawkmoth.
Autors: Yeager, D.;Zhang, F.;Zarrasvand, A.;George, N. T.;Daniel, T.;Otis, B. P.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2198 - 2209
Publisher: IEEE
 
» A TiAl2O5 nanocrystal charge trap memory device
Abstract:
A charge trapping memory device using Ti0.2Al0.8Ox film as charge trapping layer and amorphous Al2O3 as the tunneling and blocking layers was fabricated for nonvolatile memory application. TiAl2O5 nanocrystals are precipitated from the phase separation of Ti0.2Al0.8Ox film annealed at 900 °C. A memory window of 2.3 V and a stored electron density of 1×1013/cm2 were obtained. Good retention characteristics of the memory device at 80 °C were observed due to the deep charge trapping level as identified by the valence band offsets and electron energy loss spectrum measurements.
Autors: Zhou, Yue;Yin, Jiang;Xu, Hanni;Xia, Yidong;Liu, Zhiguo;Li, Aidong;Gong, Youpin;Pu, Lin;Yan, Feng;Shi, Yi;
Appeared in: Applied Physics Letters
Publication date: Oct 2010, volume: 97, issue:14, pages: 143504 - 143504-3
Publisher: IEEE
 
» A Background-Free Direction-Sensitive Neutron Detector
Abstract:
The detection and measurements of properties of neutrons are of great importance in many fields of research, including neutron scattering and radiography, measurements of solar and cosmic-ray neutron flux, measurements of neutron interaction cross sections, monitoring of neutrons at nuclear facilities, oil exploration, and searches for fissile weapons of mass destruction. Many neutron detectors are plagued by large backgrounds from X-rays and gamma rays, and most current neutron detectors lack single-event energy sensitivity or any information on neutron directionality. Even the best detectors are limited by cosmic ray neutron backgrounds. All applications would benefit from improved neutron detection sensitivity and improved measurements of neutron properties. Here, we show data from a new type of detector that can be used to determine neutron flux, energy distribution, and direction of neutron motion. The detector is free of backgrounds from X-rays, gamma rays, beta particles, and relativistic singly charged particles. It is relatively insensitive to cosmic ray neutrons because of their distinctive angular and energy distributions. It is sensitive to thermal neutrons, fission spectrum neutrons, and high-energy neutrons, with detection features distinctive for each energy range. It is capable of determining the location of a source of fission neutrons based on characteristics of elastic scattering of neutrons by helium nuclei. A portable detector could identify 1 g of reactor grade plutonium 1 m away with less than 1 min of observation time.
Autors: Ahlen, S.;Dujmic, D.;Fisher, P.;Inglis, A.;Tomita, H.;Wellenstein, H.;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Oct 2010, volume: 57, issue:5, pages: 2740 - 2746
Publisher: IEEE
 
» A Bayesian Framework for Collaborative Multi-Source Signal Sensing
Abstract:
This paper introduces a Bayesian framework to detect multiple signals embedded in noisy observations, from an array of sensors. For various states of knowledge on the communication channel and the noise at the receiving sensors, a marginalization procedure based on random matrix theory techniques, in conjunction with the maximum entropy principle, is used to compute the Neyman–Pearson hypothesis testing criterion. Quite remarkably, although rather involved, explicit expressions for the Bayesian detector are derived which enable to decide on the presence of signal sources in a noisy wireless environment. Under the hypotheses that the true channel conditions adhere the maximum entropy model, the proposed detector is the optimal Neyman–Pearson detector; if so, the performance of the derived decision criteria can be used as an upper bound for the performance of alternative detectors. In particular, simulation results are provided that suggest that the classical energy detector is close-to-optimal when the noise power is a priori known to the sensor array, especially when many sources simultaneously transmit, while the conditioning number-based detector, used classically when the noise power is unknown, is shown to perform poorly in comparison to the proposed optimal detector.
Autors: Couillet, R.;Debbah, M.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Oct 2010, volume: 58, issue:10, pages: 5186 - 5195
Publisher: IEEE
 
» A Bidirectional Three-Level DC–DC Converter for the Ultracapacitor Applications
Abstract:
Electrochemical double-layer capacitors, which are well known as ultracapacitors, have intensively been used in power conversion applications such as controlled electric drives, active filters, power conditioners, and uninterruptible power supplies. The ultracapacitor is employed as the energy storage device that can be fully charged/discharged within a few seconds. To achieve better flexibility and efficiency, the ultracapacitor is connected to the power conversion system via an interfacing dc–dc power converter. Various topologies are used as the dc–dc power converter: nonisolated two-level single-phase or multiphase interleaved converters and many varieties of isolated soft-switched dc–dc converters. A three-level nonisolated dc–dc converter as a candidate for ultracapacitor applications is proposed and analyzed in this paper. The topology is theoretically analyzed, and design guidelines are given. The modeling and control aspects are discussed. A 5.5-kW prototype was designed, and the proposed topology was experimentally verified on a general-purpose controlled electric drive. Experimental results are presented and discussed.
Autors: Grbovic, P. J.;Delarue, P.;Le Moigne, P.;Bartholomeus, P.;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Oct 2010, volume: 57, issue:10, pages: 3415 - 3430
Publisher: IEEE
 
» A Bidirectional WDM Transport System Based on RSOAs and Optoelectronic Feedback Technique
Abstract:
A bidirectional wavelength-division-multiplexing (WDM) transport system base on two reflective semiconductor optical amplifiers (RSOAs) and optoelectronic feedback technique is proposed and experimentally demonstrated. One RSOA is employed as a broadband light source and another RSOA in combination with optoelectronic feedback technique is used as wavelengths reuse and data signal remodulation scheme. System architecture is further simplified by using only one RSOA at the optical node, and system performance is further improved by optoelectronic feedback technique. Impressive performances of bit error rate (BER) (<10^-9) were achieved for both 2.5 Gbps down-link and 1.25 Gbps up-link transmissions.
Autors: Lin, Chun-Cheng;Lu, Hai-Han;Ho, Wen-Jeng;Peng, Hsiao-Chun;Li, Chung-Yi;
Appeared in: IEEE Communications Letters
Publication date: Oct 2010, volume: 14, issue:10, pages: 969 - 971
Publisher: IEEE
 
» A bifunctional cloak using transformation media
Abstract:
We theoretically explore a type of bifunctional cloak possessing both electrical and thermal cloaking functionality. We employ a composite material to design the cloak shell. By using effective medium theory, the effective electrical and thermal conductivities of the composite material should meet the perfect conductivity profile calculated from the coordinate transformation approach. In the design, we choose nonspherical nanoparticles with appropriate electrical and thermal conductivities, shape aspects, and volume fractions. Furthermore, finite element simulations are performed to verify the properties of such bifunctional cloaks.
Autors: Li, J. Y.;Gao, Y.;Huang, J. P.;
Appeared in: Journal of Applied Physics
Publication date: Oct 2010, volume: 108, issue:7, pages: 074504 - 074504-5
Publisher: IEEE
 
» A Borehole Imaging Method Using Electromagnetic Short Pulse in Oil-Based Mud
Abstract:
A borehole imaging method for nonconductive fluid application using a high-frequency electromagnetic (EM) short pulse is introduced in this letter. The pulsed borehole imaging system offers more advantages when compared with conventional dielectric or resistivity imaging tools. The continuous measurement in a wideband spectrum improves accuracy and provides comprehensive well-bore formation analysis information. A high resolution in both vertical and horizontal directions for well-bore cracks, rugosity, and dielectric dispersion of formations can be obtained by radiating an EM pulse signal with a center frequency of 1.2 GHz into a well-bore via a wideband antenna system. This design has been proven to work effectively in oil-based mud and may be used as an alternative tool for logging while drilling imaging applications. By using the transmission line matrix method, numerical simulation results are presented to verify the performance of the proposed EM pulse imaging system. An improved wideband bow-tie antenna is designed for a proposed multispacing EM pulsed imaging system as well.
Autors: Guo, C.;Liu, R. C.;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Oct 2010, volume: 7, issue:4, pages: 856 - 860
Publisher: IEEE
 
» A Bus-Bar-Like Power Module Based on Three-Dimensional Power-Chip-on-Chip Hybrid Integration
Abstract:
This paper focuses on a new generation of power modules, trying to optimize the tradeoff between thermal and electromagnetic interference (EMI) managements. At the same time, the packaging technique is considered in order to simplify the implementation of the power dies while improving the reliability of the structure. The approach considers the hybrid integration of the power dies, one on top of the other, into a 3-D power-chip-on-chip configuration. Due to this structure, the power dies can directly be inserted within electrical plates, with the whole structure emulating a bus-bar-like power module. This paper presents the characteristics and the benefits of this approach. Then, it focuses on the practical characterizations of two prototypes having their active components packaged with the presented technique: a buck converter structure and a full-bridge single-phase diode rectifier. Both of them are based on double-sided thermal cooling, and electrothermal contacts are obtained by pressure. The prototypes exhibit great performances while offering really reduced parasitic and EMI coupling.
Autors: Vagnon, E.;Jeannin, P.-O.;Crebier, J.-C.;Avenas, Y.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Oct 2010, volume: 46, issue:5, pages: 2046 - 2055
Publisher: IEEE
 
» A CAE system for micromachines: its application to electrostatic micro wobble actuator
Abstract:
This paper describes a new computer-aided engineering (CAE) system for micromachines 10-6-10-3 m in size. An automatic finite-element (FE) mesh-generation technique, which is based on the fuzzy knowledge processing and computational geometry techniques, is incorporated into the system, together with a commercial FE analysis code, MARC, and a commercial solid modeler, DESIGNBASE. The system allows a geometry model of interest to be automatically converted to different FE models, depending on the physical phenomena of the micromachines to be analyzed, i.e., electrostatic analysis, stress analysis, modal analysis, and so on. The FE models are then automatically analyzed using the FE analysis...
Autors: J.S., Lee , S., Yoshimura , G., Yagawa , N., Shibaike
Appeared in: Sensors and Actuators A: Physical
Publication date: Oct 2010
Publisher: Elsevier B.V.
 
» A Channel Rendezvous Scheme for Cognitive Radio Networks
Abstract:
Cognitive radio networks need to utilize available spectrum in a dynamic and opportunistic fashion without causing interference to co-located primary nodes. Before data transmission begins, secondary nodes must establish a link on a channel which is not occupied by primary nodes. Unfortunately, in cognitive radio networks, the set of available channels can be different for each node, since it is determined by the relative locations of nodes to primary nodes. We are the first to present a distributed channel rendezvous scheme which finds a commonly available channel between any two nodes in a bounded time without synchronization. Our scheme determines the order, in which two nodes visit channels to find a common channel, if any, within a bounded time.
Autors: Shin, Jongmin;Yang, Dongmin;Kim, Cheeha;
Appeared in: IEEE Communications Letters
Publication date: Oct 2010, volume: 14, issue:10, pages: 954 - 956
Publisher: IEEE
 
» A Charging Acceleration Technique for Highly Efficient Cascode Class-E CMOS Power Amplifiers
Abstract:
A cascode configuration in class-E CMOS power amplifiers (PAs) provides high reliability with respect to breakdown considerations. However, it causes a power loss due to the slow transition of a common-gate device from the triode region to the cut-off region. To minimize the power loss of cascode class-E CMOS PAs, we propose a charging acceleration technique, CAT. This method incorporates a capacitive element between the drain and the source of a common-gate device in a cascode configuration, accelerating the charging speed responsible for turning off a common-gate device instantly after a common-source device is turned off and thus minimizing power loss from the device. We compared the performance of the proposed cascode class-E PA to that of the conventional cascode class-E PA using a 0.18- CMOS process. With a 3.3-V power supply, the proposed fully-integrated CMOS PA achieves 30.7 dBm of maximum output power and 45.6% of power-added efficiency (PAE) with a dynamic range of 40 dB at 1.6 GHz. According to measurements, the proposed cascode class-E PA shows improvement in PAE over the conventional class-E PA of between 5% and 9% in a 1.5 to 2.0 GHz range.
Autors: Lee, O.;Han, J.;An, K. H.;Lee, D. H.;Lee, K.-S.;Hong, S.;Lee, C.-H.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Oct 2010, volume: 45, issue:10, pages: 2184 - 2197
Publisher: IEEE
 
» A Clustering-Based Method for Quantifying the Effects of Large On-Grid PV Systems
Abstract:
Analyzing the impacts of large on-grid photovoltaic (PV) systems on the performance of the electric network is an essential task prior to the installation of these systems. To quantify these impacts, a method based on chronological simulations can be used. The main advantage of this method is its ability to provide information about the impacts of the fluctuation of the power generated from the PV systems. However, this method requires performing extensive analysis and simulations, making it impractical for utility studies, especially if long historical data with subhourly time resolution is used. In this paper, a new method that utilizes the data efficiently while preserving the temporal information of the generated PV power is proposed. The method takes advantage of the clustering techniques to group together segments of the output PV power having similar features. Hence, a representative segment for each group can be chosen and used in the analysis and simulations. This representative segment can provide information about the expected performance of other segments of the group. The validity and usefulness of the proposed method are demonstrated by identifying the suitable size and site of a large PV system.
Autors: Omran, W. A.;Kazerani, M.;Salama, M. M. A.;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2010, volume: 25, issue:4, pages: 2617 - 2625
Publisher: IEEE
 
» A Communication Robot in a Shopping Mall
Abstract:
This paper reports our development of a communication robot for use in a shopping mall to provide shopping information, offer route guidance, and build rapport. In the development, the major difficulties included sensing human behaviors, conversation in a noisy daily environment, and the needs of unexpected miscellaneous knowledge in the conversation. We chose a network-robot system approach, where a single robot's poor sensing capability and knowledge are supplemented by ubiquitous sensors and a human operator. The developed robot system detects a person with floor sensors to initiate interaction, identifies individuals with radio-frequency identification (RFID) tags, gives shopping information while chatting, and provides route guidance with deictic gestures. The robot was partially teleoperated to avoid the difficulty of speech recognition as well as to furnish a new kind of knowledge that only humans can flexibly provide. The information supplied by a human operator was later used to increase the robot's autonomy. For 25 days in a shopping mall, we conducted a field trial and gathered 2642 interactions. A total of 235 participants signed up to use RFID tags and, later, provided questionnaire responses. The questionnaire results are promising in terms of the visitors’ perceived acceptability as well as the encouragement of their shopping activities. The results of the teleoperation analysis revealed that the amount of teleoperation gradually decreased, which is also promising.
Autors: Kanda, T.;Shiomi, M.;Miyashita, Z.;Ishiguro, H.;Hagita, N.;
Appeared in: IEEE Transactions on Robotics
Publication date: Oct 2010, volume: 26, issue:5, pages: 897 - 913
Publisher: IEEE
 
» A Compact 0.1–14-GHz Ultra-Wideband Low-Noise Amplifier in 0.13- CMOS
Abstract:
A compact ultra-wideband low-noise amplifier (LNA) with a 12.4-dB maximum gain, a 2.7-dB minimum noise figure (NF), and a bandwidth over 0.1–14 GHz is realized in a 0.13- CMOS technology. The circuit is basically an inductorless configuration using the resistive-feedback and current-reuse techniques for wideband and high-gain characteristics. It was found that a small inductor of only 0.4 nH can greatly improve the circuit performance, which enhances the bandwidth by 23%, and reduces the NF by 0.94 dB (at 10.6 GHz), while only consuming an additional area of . The LNA only occupies a core area of , and consumes 14.4 mW from a 1.8-V supply.
Autors: Chang, P.-Y.;Hsu, S. S. H.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Oct 2010, volume: 58, issue:10, pages: 2575 - 2581
Publisher: IEEE
 
» A Compact Fully-Integrated Extremum-Selector-Based Soft-Start Circuit for Voltage Regulators in Bulk CMOS Technologies
Abstract:
A fully-integrated soft-start circuit for voltage regulators is presented in this brief. A soft-start strategy based on an extremum selector and a linearly ramped-up reference is developed to prevent any massive in-rush current through the power device during the start-up phase of the regulator. The strategy is realized by a compact on-chip circuit that requires no external components and has minimal transistor overhead, thereby minimizing the implementation area and the cost of the overall regulator. The linearly ramped-up reference is created through the use of nonlinear MOS capacitors available in a low-cost bulk CMOS technology. The proposed soft-start circuit has been implemented in a 0.35- bulk CMOS technology as part of a 50-mA linear regulator. The proposed circuit occupies 0.013 on silicon, which corresponds to about 13% of the total area of the linear regulator. The soft-start circuit enables the output voltage of the regulator to be linearly ramped up to the steady state under different load currents and charging currents.
Autors: Al-Shyoukh, M.;Lee, H.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Oct 2010, volume: 57, issue:10, pages: 818 - 822
Publisher: IEEE
 
» A Compact Model for Undoped Symmetric Double-Gate Polysilicon Thin-Film Transistors
Abstract:
A physics-based solution to the surface potential and potential in the middle of the film for the symmetric undoped or light-doped double-gate (DG) polysilicon thin-film transistors (poly-Si TFTs) has been derived from the one-dimensional (1-D) Poisson's equation. The calculation of the channel potential accounts for an exponential distribution of defect states' density. It provides a good description of surface potential over different regions of operation. Comparison with numerical data shows that the solution serves as a good approximation to potential under different conditions. The characteristics of the drain current at DG poly-Si TFTs based on terms of surface potential have been described and modeled in this paper. The resulting drain current characteristics show a good agreement with two-dimensional (2-D) numerical device simulations with a minimum of parameters, and also a good match to the DG poly-Si TFTs experimental data.
Autors: Huang, J;Deng, W;Zheng, X;Jiang, X;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Oct 2010, volume: 57, issue:10, pages: 2607 - 2615
Publisher: IEEE
 
» A compact streak camera for 150 fs time resolved measurement of bright pulses in ultrafast electron diffraction
Abstract:
We have developed a compact streak camera suitable for measuring the duration of highly charged subrelativistic femtosecond electron bunches with an energy bandwidth in the order of 0.1%, as frequently used in ultrafast electron diffraction (UED) experiments for the investigation of ultrafast structural dynamics. The device operates in accumulation mode with 50 fs shot-to-shot timing jitter, and at a 30 keV electron energy, the full width at half maximum temporal resolution is 150 fs. Measured durations of pulses from our UED gun agree well with the predictions from the detailed charged particle trajectory simulations.
Autors: Kassier, G. H.;Haupt, K.;Erasmus, N.;Rohwer, E. G.;von Bergmann, H. M.;Schwoerer, H.;Coelho, S. M. M.;Auret, F. D.;
Appeared in: Review of Scientific Instruments
Publication date: Oct 2010, volume: 81, issue:10, pages: 105103 - 105103-5
Publisher: IEEE
 
» A comparative review of commercial vs. tactical wireless networks
Abstract:
This article presents a comparison between commercial and tactical wireless networks, pointing to their different requirements, expectations, needs, and constraints for information assurance and so on. This comparative study demonstrates why commercial wireless networks have made more technological leaps than tactical wireless networks. The article introduces a model for tactical wireless networks based on the architectures that have been pursued (especially the Joint Tactical Radio System and the Future Force vision) within the last decade or so. The model draws parallels with commercial wireless networks to allow tactical wireless networks a plausible opportunity to achieve similar technological advancements.
Autors: Elmasry, G.F.;
Appeared in: IEEE Communications Magazine
Publication date: Oct 2010, volume: 48, issue:10, pages: 54 - 59
Publisher: IEEE
 
» A comparison between physical properties of carbon black-polymer and carbon nanotubes-polymer composites
Abstract:
Multiple-walled carbon nanotube (CNT)-and carbon black (CB)-polymer composites have been fabricated by mechanical mixing with different loadings, the polymeric matrix being identical between the two series of samples. The main focus of this work is to report measurements of physical properties of these mixtures in ambient conditions and to discuss the origin of similarities and differences among them according the kind of carbonaceous filler. The uniform dispersion of the carbonaceous phase in the dielectric matrix was probed by high-resolution transmission electron microscopy. The good dispersibility of the filler particle is also reflected in the much lower conduction threshold observed for CNT-containing samples than in the CB composites. This is likely due to the high aspect ratio of the CNTs. Mechanical properties show that the storage modulus of the two kinds of samples is close to the modulus value of the neat styrene-butadiene rubber (SBR), independent of filler content over a wide range of compositions (Φ<0.1) encompassing the percolation threshold. Microwave measurements show that the real part of the effective permittivity exhibits a flat frequency response, with the exception of the sample containing 30 vol% CB for which an inverse-power law is observed revealing a behavior that has been seen for many random heterogeneous soft materials. No resonant dielectric absorption is evidenced within the frequency range explored and for the filler concentrations investigated. The results were also compared with analytical effective (mean-field) models. The symmetric Bruggeman model is in very good agreement with the microwave effective permittivity once account is taken of the depolarization factor which is close to the value found for a three-dimensional (3D) random dispersion of monodisperse spherical conductive inclusions within a dielectric matrix. By combining micr- - owave frequency-domain spectroscopy with uniaxial tension, we obtain the effective permittivity as a function of the elongation ratio. Our results indicate that the effective permittivity spectrum of the CNT-polymer samples and their CB-based counterparts is not very sensitive to the applied stress in the range of elongation ratios explored. For the sample containing 30 vol% CB, the relative variation in the effective permittivity as a function of the elongation ratio is well described by the Gaussian molecular network model. The experimentally determined mechanical and microwave properties of these nanocomposites is related to the change in the mesostructure, formed by the heterogeneous 3D interconnected network of polymer and of aggregates (or agglomerates) of filler particles, as the composite is stretched. The results of this study provide another insight and opportunities to the comprehension of multifunctional materials, including novel nanoelectronic components, and carbon-based systems.
Autors: Adohi, B. J.-P.;Mdarhri, A.;Prunier, C.;Haidar, B.;Brosseau, C.;
Appeared in: Journal of Applied Physics
Publication date: Oct 2010, volume: 108, issue:7, pages: 074108 - 074108-11
Publisher: IEEE
 
» A Comparison of Six UML-Based Languages for Software Process Modeling
Abstract:
Describing and managing activities, resources, and constraints of software development processes is a challenging goal for many organizations. A first generation of Software Process Modeling Languages (SPMLs) appeared in the 1990s but failed to gain broad industrial support. Recently, however, a second generation of SPMLs has appeared, leveraging the strong industrial interest for modeling languages such as UML. In this paper, we propose a comparison of these UML-based SPMLs. While not exhaustive, this comparison concentrates on SPMLs most representative of the various alternative approaches, ranging from UML-based framework specializations to full-blown executable metamodeling approaches. To support the comparison of these various approaches, we propose a frame gathering a set of requirements for process modeling, such as semantic richness, modularity, executability, conformity to the UML standard, and formality. Beyond discussing the relative merits of these approaches, we also evaluate the overall suitability of these UML-based SPMLs for software process modeling. Finally, we discuss the impact of these approaches on the current state of the practice, and conclude with lessons we have learned in doing this comparison.
Autors: Bendraou, Reda;Jezequel, Jean-Marc;Gervais, Marie-Pierre;Blanc, Xavier;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Oct 2010, volume: 36, issue:5, pages: 662 - 675
Publisher: IEEE
 
» A Composite Transistor to Suppress Kink Phenomenon in HBTs for Broadband Design
Abstract:
The kink phenomenon in heterojunction bipolar transistors (HBTs) is introduced and mathematically analyzed. A novel composite transistor based on feedback theory is proposed to suppress the kink phenomenon with negligible increase in chip area and power consumption. According to the small-signal analysis, the output impedance of the composite transistor can be represented by an RC series circuit. Thus, the output resistance is a constant value over a wide frequency range. A test die using 2- InGaP/GaAs HBT technology from AWSC is fabricated, and a constant real part of S22 is measured from 0.1 to 20 GHz (approaching the HBT's unity-gain frequency). The proposed composite transistor can significantly ease the design for output matching and broadband amplifiers.
Autors: Gao, H.;Sun, X.;Hua, Y.;Zhang, X.;Wang, R.;Li, G. P.;
Appeared in: IEEE Electron Device Letters
Publication date: Oct 2010, volume: 31, issue:10, pages: 1113 - 1115
Publisher: IEEE
 
» A Comprehensive Framework for Image Inpainting
Abstract:
Inpainting is the art of modifying an image in a form that is not detectable by an ordinary observer. There are numerous and very different approaches to tackle the inpainting problem, though as explained in this paper, the most successful algorithms are based upon one or two of the following three basic techniques: copy-and-paste texture synthesis, geometric partial differential equations (PDEs), and coherence among neighboring pixels. We combine these three building blocks in a variational model, and provide a working algorithm for image inpainting trying to approximate the minimum of the proposed energy functional. Our experiments show that the combination of all three terms of the proposed energy works better than taking each term separately, and the results obtained are within the state-of-the-art.
Autors: Bugeau, A.;Bertalmio, M.;Caselles, V.;Sapiro, G.;
Appeared in: IEEE Transactions on Image Processing
Publication date: Oct 2010, volume: 19, issue:10, pages: 2634 - 2645
Publisher: IEEE
 
» A Computationally Efficient Procedure for the Design of Robust Broadband Beamformers
Abstract:
Broadband beamformers using superdirective arrays are sensitive to errors in the sensor characteristics. Recently, a method that considers the probability distributions of errors to synthesize a robust optimal beamformer has been proposed. Unfortunately, the entire synthesis process may become unacceptably long due to the computational burden of the cost function. Here, we present an alternative procedure for computing the same cost function, drastically reducing such a problem.
Autors: Crocco, M.;Trucco, A.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Oct 2010, volume: 58, issue:10, pages: 5420 - 5424
Publisher: IEEE
 
» A continuum framework for grain boundary diffusion in thin film/substrate systems
Abstract:
A two-dimensional continuum model is developed for stress relaxation in thin films through grain boundary (GB) diffusion. When a thin film with columnar grains is subjected to thermal stress, stress gradients along the GBs are relaxed by diffusion of material from the film surface into the GBs. The transported material constitutes a wedge and becomes the source of stress inside the adjacent elastic grains that are perfectly bonded to the substrate. In the model, the coupling between diffusion and elasticity is obtained by numerically solving the governing equations in a staggered manner. A finite difference scheme is used to solve the diffusion equations, modified in order to implement realistic boundary conditions, while the elasticity problem is solved with the finite element method. The solutions reveal the existence of a universal power law scaling between the unrelaxed fraction of stress and the grain aspect ratio. For slender grains, the GB wedge attains a more uniform shape and relaxation is more effective. The kinetics of the process depends not only on the grain aspect ratio but also strongly on the thickness of the film. In case there is no adhesion between film and substrate, complete stress relaxation is attained albeit at a slightly slower rate.
Autors: Ayas, Can;van der Giessen, Erik;
Appeared in: Journal of Applied Physics
Publication date: Oct 2010, volume: 108, issue:7, pages: 073511 - 073511-10
Publisher: IEEE
 
» A control theory approach to clock steering techniques
Abstract:
Several clock and time scale steering methods have been developed according to different viewpoints by various time laboratories. By resorting to control theory ideas, we propose a common theoretical framework encompassing these methods. A comparison of the most common steering methodologies, namely, the classical steering approach, the GPS bang-bang method, and the linear quadratic Gaussian technique, is carried out. We believe that the use of control theory methods can potentially lead to a better understanding of clock steering algorithms.
Autors: Farina, M.;Galleani, L.;Tavella, P.;Bittanti, S.;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Oct 2010, volume: 57, issue:10, pages: 2257 - 2270
Publisher: IEEE
 
» A Coupled Global Registration and Segmentation Framework With Application to Magnetic Resonance Prostate Imagery
Abstract:
Extracting the prostate from magnetic resonance (MR) imagery is a challenging and important task for medical image analysis and surgical planning. We present in this work a unified shape-based framework to extract the prostate from MR prostate imagery. In many cases, shape-based segmentation is a two-part problem. First, one must properly align a set of training shapes such that any variation in shape is not due to pose. Then segmentation can be performed under the constraint of the learnt shape. However, the general registration task of prostate shapes becomes increasingly difficult due to the large variations in pose and shape in the training sets, and is not readily handled through existing techniques. Thus, the contributions of this paper are twofold. We first explicitly address the registration problem by representing the shapes of a training set as point clouds. In doing so, we are able to exploit the more global aspects of registration via a certain particle filtering based scheme. In addition, once the shapes have been registered, a cost functional is designed to incorporate both the local image statistics as well as the learnt shape prior. We provide experimental results, which include several challenging clinical data sets, to highlight the algorithm's capability of robustly handling supine/prone prostate registration and the overall segmentation task.
Autors: Gao, Y.;Sandhu, R.;Fichtinger, G.;Tannenbaum, A. R.;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Oct 2010, volume: 29, issue:10, pages: 1781 - 1794
Publisher: IEEE
 
» A Data Hiding Algorithm for H.264/AVC Video Streams Without Intra-Frame Distortion Drift
Abstract:
Intra-frame distortion drift is a big problem of data hiding in H.264/AVC video streams. Based on a thorough investigation of this problem, a novel readable data-hiding algorithm, which can embed data into the quantized discrete cosine transform (DCT) coefficients of I frames without bringing any intra-frame distortion drift into the H.264/advanced video coding (AVC) video host, is presented in this paper. We exploit several paired-coefficients of a 4 4 DCT block to accumulate the embedding induced distortion. The directions of intra-frame prediction are utilized to avert the distortion drift. It is proved analytically and shown experimentally that the proposed algorithm can achieve high embedding capacity and low visual distortion. Performance comparisons with other existing schemes are provided to demonstrate the superiority of the proposed scheme.
Autors: Ma, X.;Li, Z.;Tu, H.;Zhang, B.;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Oct 2010, volume: 20, issue:10, pages: 1320 - 1330
Publisher: IEEE
 
» A DC behavioral electrical model for quasi-linear spin-valve devices including thermal effects for circuit simulation
Abstract:
An advanced model for quasi-linear spin-valve (SV) structures is presented for circuit simulation purposes. The model takes into account electrical and thermal effects in a coupled way in order to allow a coherent representation of the sensor physics for design purposes of electronics applications based on these sensor devices. The model was implemented in Verilog-A and used in a commercial circuit simulator. For testing the model, different SV structures have been specifically fabricated and measured. The characterization included DC measurements as well as steady-state and transient thermal analysis. From the experimental data, the parameters of the model have been extracted....
Autors: Andrés M., Roldán , Juan B., Roldán , Càndid, Reig , M.-D., Cubells-Beltrán , Diego, Ramírez , ...
Appeared in: Microelectronics Journal
Publication date: Oct 2010
Publisher: Elsevier B.V.
 
» A Decision Tree-Based Method for Fault Classification in Double-Circuit Transmission Lines
Abstract:
In this paper, a novel method for fault classification of double-circuit transmission lines is presented. The proposed method needs voltages and currents of only one side of the protected line. After detecting the exact time of fault inception and calculating the odd harmonics of the measured signals, up to the nineteenth, a decision tree algorithm has been employed for recognition of the intercircuit fault type. Also, the proposed method is extended for classification of crossover faults in these transmission lines. Simulation results have shown that the proposed method can classify the faults in less than a quarter of a cycle with the highest possible accuracy.
Autors: Jamehbozorg, A.;Shahrtash, S. M.;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2010, volume: 25, issue:4, pages: 2184 - 2189
Publisher: IEEE
 
» A Decision-Tree-Based Method for Fault Classification in Single-Circuit Transmission Lines
Abstract:
In this paper, a novel method for fault classification in single-circuit transmission lines is presented. The proposed method needs voltages and currents of only one side of the protected line. After detecting the exact time of fault inception, the fault type is recognized by means of a decision-tree algorithm (DT) which is formerly trained by applying the odd harmonics of the measured signals, up to the 19th. Simulation results have shown that the proposed method can classify the faults in less than a quarter of a cycle with highest possible accuracy.
Autors: Jamehbozorg, A.;Shahrtash, S. M.;
Appeared in: IEEE Transactions on Power Delivery
Publication date: Oct 2010, volume: 25, issue:4, pages: 2190 - 2196
Publisher: IEEE
 

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