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Electrical and Electronics Engineering publications abstract of: 03-2011 sorted by title, page: 0
» "Bi-Bellows: Pneumatic Bending Actuator"
Abstract:
We present a compliant single degree-of-freedom pneumatic actuator with large bending capabilities. Several actuator designs are compared and validated against the suggested actuation model. Repeatability, some dynamic properties and the affect of external loads are examined as well.
Autors: Yoel, Shapiro , Alon, Wolf , Kosa, Gabor
Appeared in: Sensors and Actuators A: Physical
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» "Weighting for more": Enhancing characteristic-function based ica with asymptotically optimal weighting???
Abstract:
The CHaracteristic-function-Enabled Source Separation (CHESS) method for independent component analysis (ICA) is based on approximate joint diagonalization (AJD) of Hessians of the observations' empirical log-characteristic-function, taken at selected off-origin "processing points". As previously observed in other contexts, the AJD performance can be significantly improved by optimal weighting, using the inverse of the covariance matrix of all of the off-diagonal terms of the target-matrices. Fortunately, this apparently cumbersome weighting scheme takes a convenient form under the assumption that the mixture is already "nearly-separated", e.g., following some initial separation. We derive covariance expressions for the Sample-Hessian matrices, and show that under the...
Autors: Alon, Slapak , Arie, Yeredor
Appeared in: Signal Processing
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» 1.3- m 4 25-Gb/s Monolithically Integrated Light Source for Metro Area 100-Gb/s Ethernet
Abstract:
A 1.3- monolithically integrated light source for metro area 100-Gb/s Ethernet is developed. Four 25-Gb/s electroabsorption modulators integrated with distributed-feedback lasers and their multiplexer are monolithically integrated on one chip. A shallow ridge waveguide is used for lasers and modulators for large modulation bandwidth, and a deep ridge waveguide is used for the multiplexer region due to its low bending and radiation losses. The integration of hetero-waveguide devices enables the very small chip size of 2 2.6 . With the device, 100-Gb/s (4 25-Gb/s simultaneous) operation is demonstrated with the clear eye-openings, and error-free 40-km single-mode fiber transmission is achieved for the first time.Pub _bookmark Command="[Quick Mark]"
Autors: Fujisawa, T.;Kanazawa, S.;Ishii, H.;Nunoya, N.;Kawaguchi, Y.;Ohki, A.;Fujiwara, N.;Takahata, K.;Iga, R.;Kano, F.;Oohashi, H.;
Appeared in: IEEE Photonics Technology Letters
Publication date: Mar 2011, volume: 23, issue:6, pages: 356 - 358
Publisher: IEEE
 
» 12-b Enhanced Input Range On-Chip Quasi-Digital Converter With Temperature Compensation
Abstract:
This brief presents a monolithic 1.8-V 0.18- CMOS temperature-compensated voltage-to-frequency converter for sensor read-out interfaces in wireless sensor network applications. Measurement results show that the proposed converter features are suitable for an output frequency span of 2 MHz with an input voltage range of 0.1–1.6 V. This converter presents a relative error below 4.8% and a linearity error below 0.017% (i.e., 12 b) over the whole frequency span for a range of ( , ). Power consumption is 0.423 mW (20 nW in sleep mode), and it occupies an active area of .
Autors: Azcona, C.;Calvo, B.;Medrano, N.;Bayo, A.;Celma, S.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Mar 2011, volume: 58, issue:3, pages: 164 - 168
Publisher: IEEE
 
» 19.7% Efficient All-Screen-Printed Back-Contact Back-Junction Silicon Solar Cell With Aluminum-Alloyed Emitter
Abstract:
A back-contact back-junction solar cell on n-type silicon with an aluminum-alloyed emitter is introduced, where both structuring and metallization are realized by screen-printing. The process sequence for realizing the cell with a pitch of 2 mm is displayed and described. The cell parameters are shown for three different emitter coverages on the rear side (45%, 58%, and 72%). An analysis of the saturation current density of the different areas was carried out on lifetime samples, and the calculated is compared to the measured one. The potentially critical edge of the Al finger is analyzed in a scanning electron microscopy cross section. No damaging of the aluminum paste to the passivation layer and a homogenous -layer over the whole finger width is observed. A conversion efficiency of 19.7% is presented for a cell with an aperture area of 16.65 that was exclusively processed in Fraunhofer ISE PV-TEC, which is an industrial-like fabrication environment.
Autors: Woehl, R.;Krause, J.;Granek, F.;Biro, D.;
Appeared in: IEEE Electron Device Letters
Publication date: Mar 2011, volume: 32, issue:3, pages: 345 - 347
Publisher: IEEE
 
» 2010 Outstanding Editorial Service Awards
Abstract:
Autors: Wang, F.-Y.;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Mar 2011, volume: 12, issue:1, pages: 1 - 1
Publisher: IEEE
 
» 3D flowerlike ZnO micro-nanostructures via site-specific second nucleation in the zinc-ethylenediamine-hexamethylenetetramine tertiary system
Abstract:
Three-dimensional flowerlike ZnO micro-nanostructures were fabricated from aqueous solution in the zinc-ethylenediamine (EDA)-hexamethylenetetramine (HMT) tertiary system at relatively low temperature (95°C) in 2h, via selective adsorption and site-specific second nucleation of EDA and selective adsorption of growth units. The obtained ZnO micro-nanostructures exhibit well-defined flowerlike morphology, hexagonal wurtzite structure and strong UV photoluminescence. The petals, which present hexagonal pyramidal feature, are single crystal and preferentially growing along the [0001] direction. Effects of EDA, HMT, concentration and temperature were investigated. It shows that the EDA is crucial to the formation of 3D flowerlike ZnO by selective adsorption and site-specific second nucleation,...
Autors: Lejiao, Yang , Deliang, Qiu , Fei, Yu , Shougang, Chen , Yansheng, Yin
Appeared in: Materials Science in Semiconductor Processing
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» 3D Simulation of Triple-Gate MOSFETs with different mobility regions
Abstract:
In this paper we present a new approach for analyzing 3D structure triple-gate MOSFETs using three different regions, one at the top and two in the sidewalls of the fin, which allows for considering different carrier mobilities in each region due to crystalline orientation and technological processing. A procedure for the extraction of the mobility parameters in each region is developed. Robustness of the proposed structure is validated by experimental data obtained on FinFETs. A very good agreement is obtained between experimental and simulated characteristics.
Autors: J., Conde , A., Cerdeira , M., Pavanello , V., Kilchytska , D., Flandre
Appeared in: Microelectronic Engineering
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» 4G: Engineering versus Marketing
Abstract:
Is the increasing number of mobile devices advertised as 4G a product of marketing hype, or does it represent the traditionally assumed one-order-of magnitude improvement over the previous generation of cellular architectures?
Autors: Lawton, George;
Appeared in: Computer
Publication date: Mar 2011, volume: 44, issue:3, pages: 14 - 16
Publisher: IEEE
 
» 1/f noise in MgO double-barrier magnetic tunnel junctions
Abstract:
Low frequency noise has been investigated in MgO double-barrier magnetic tunnel junctions (DMTJs) with tunneling magnetoresistance (TMR) ratios up to 250% at room temperature. The noise shows a 1/f frequency spectrum and the minimum of the noise magnitude parameter is 1.2×10-10 μm2 in the parallel state for DMTJs annealed at 375 °C. The bias dependence of noise and TMR suggests that DMTJs with MgO barriers can be useful for magnetic field sensor applications.
Autors: Yu, G. Q.;Diao, Z.;Feng, J. F.;Kurt, H.;Han, X. F.;Coey, J. M. D.;
Appeared in: Applied Physics Letters
Publication date: Mar 2011, volume: 98, issue:11, pages: 112504 - 112504-3
Publisher: IEEE
 
» Al2O3/GeOx/Ge gate stacks with low interface trap density fabricated by electron cyclotron resonance plasma postoxidation
Abstract:
An electron cyclotron resonance (ECR) plasma postoxidation method has been employed for forming Al2O3/GeOx/Ge metal-oxide-semiconductor (MOS) structures. X-ray photoelectron spectroscopy and transmission electron microscope characterizations have revealed that a GeOx layer is formed beneath the Al2O3 capping layer by exposing the Al2O3/Ge structures to ECR oxygen plasma. The interface trap density (Dit) of Au/Al2O3/GeOx/Ge MOS capacitors is found to be significantly suppressed down to lower than 1011 cm-2eV-1. Especially, a plasma postoxidation time of as short as 10 s is sufficient to reduce Dit with maintaining the equivalent oxide thickness (EOT). As a result, the minimum Dit values and EOT of 5×1010 cm-2eV-1 and 1.67 nm, and 6×1010 cm-2eV-1 and 1.83 nm have been realized for Al2O3/GeOx/Ge MOS structures with p- and n-type substrates, respectively.
Autors: Zhang, R.;Iwasaki, T.;Taoka, N.;Takenaka, M.;Takagi, S.;
Appeared in: Applied Physics Letters
Publication date: Mar 2011, volume: 98, issue:11, pages: 112902 - 112902-3
Publisher: IEEE
 
» A 0.18?m CMOS linear-in-dB AGC post-amplifier for optical communications
Abstract:
This paper presents a fully integrated 10GBase-LX4 Ethernet receiver front-end automatic gain control amplifier realized in a 0.18?m CMOS process. Based on a very compact and reliable inductorless design, the proposed differential post-amplifier, comprises three main digitally programmable gain stages, a DC offset cancellation network and an automatic gain feedback control loop. Experimental results demonstrate a -3dB cut-off frequency above 2.3GHz over a -3 to 33dB linear-in-dB controlled gain range with a sensitivity of 2.0mVp-p with a BER of 10-12 at 2.5Gb/s. For the aforementioned standard, 3.125Gb/s, an input dynamic range above 50dB is achieved, from 2.5mVp-p to 800mVp-p, indicating...
Autors: Francisco, Aznar , Santiago, Celma , Belén, Calvo
Appeared in: Microelectronics Reliability
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A 0.6 V 10 GHz CMOS VCO Using a Negative-Gm Back-Gate Tuned Technique
Abstract:
Without an extra on-chip accumulation-mode MOS varactor, a voltage-controlled oscillator (VCO) using a negative-transconductance back-gate tuned technique is demonstrated in a standard 0.18 CMOS process to achieve low-voltage, wide-range and high-frequency designs. Employing the varied p-n junction capacitance and the varied transconductance in the intrinsic-tuned regime, the VCO provides the tuning range of 9.95 to 11.05 GHz at a 0.6 V supply and dissipates below 4.35 mW. At 11 GHz carrier frequency, the measured phase noise is at a 1 MHz offset.
Autors: Yang, C.-Y.;Chang, C.-H.;Lin, J.-M.;Weng, J.-H.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2011, volume: 21, issue:3, pages: 163 - 165
Publisher: IEEE
 
» A 1-V Process-Insensitive Current-Scalable Two-Stage Opamp With Enhanced DC Gain and Settling Behavior in 65-nm Digital CMOS
Abstract:
A pseudo-cascode compensation technique is proposed to enable a process-insensitive and current-scalable design of the classical two-stage opamp at low supply voltages, without requiring any additional power dissipation. Furthermore, a bulk-biasing technique is proposed to enhance the dc gain of the two-stage opamp, without affecting its output-voltage swing and without requiring any additional power dissipation. To compare the performance advantages of the proposed pseudo-cascode compensation technique versus classical Miller compensation in a two-stage opamp with/without applying the proposed bulk-biasing technique, four opamps were fabricated on the same die in a 1-V 65-nm CMOS process. The corresponding transistors in all four opamps had equal sizes. Furthermore, all four opamps had equal total compensation capacitance and the same total power dissipation. Accordingly, compared to using Miller compensation, by applying the proposed pseudo-cascode-compensation and bulk-biasing techniques in a two-stage opamp, the opamp's dc gain is increased by a factor of 4 (12 dB), its unit-gain frequency is increased by 40%, and its phase margin is maintained over a factor of 100 scaling in its bias current. Furthermore, the overshoot in its large-signal step response is eliminated and the rise/fall settling times are improved by 33%. The trade-off is a minimal decrease in the opamp's phase margin. Importantly, this is all achieved without affecting the opamp's output-voltage swing and without requiring any additional power dissipation.
Autors: Taherzadeh-Sani, M.;Hamoui, A. A.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 660 - 668
Publisher: IEEE
 
» A 100 MHz Ladder FeRAM Design With Capacitance-Coupled-Bitline (CCB) Cell
Abstract:
This paper proposes a new ladder FeRAM architecture with capacitance-coupled-bitline (CCB) cells for high-end embedded applications. The ladder FeRAM architecture short-circuits both electrodes of each ferroelectric capacitor at every standby cycle. This overcomes the fatal disturbance problem inherent to the CCB cell, and halves read/write cycle time by sharing a plateline and its driver with 32 cells in two neighboring ladder blocks. This configuration realizes small 0.35 cell using a highly reliable ferroelectric capacitor of as large as 0.145 size, and a highly compatible process with logic-LSI. A slow plateline drive of the CCB cell due to a resistive plateline using an active area is minimized to 2.5 ns by introducing thick M3 shunt-path and distributed M3 platelines. The area penalty of the shunt is 4.7% of an array. A serious bitline-to-bitline coupling noise in edge bitlines up to the noise/signal ratio of 0.38 due to the operation peculiar to FeRAM is eliminated by introducing activated dummy bitlines and their sense amplifiers. The design of 16 cells in a ladder block is optimal for effective cell size, cell signal, and active power dissipation. A new early plateline pull-down read scheme omits “0”-data rewrite operation without read disturbance. A 64 Kb ladder FeRAM with the CCB cells and the early plateline pull-down read scheme achieves a fast random read/write of 10 ns cycle and 8 ns access at 150 .
Autors: Takashima, D.;Nagadomi, Y.;Ozaki, T.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 681 - 689
Publisher: IEEE
 
» A 140-GHz Two-Beam Overmoded Folded-Waveguide Traveling-Wave Tube
Abstract:
A folded-waveguide (FW) traveling-wave tube (TWT) with two electron beams, which operates at the higher order mode, is simulated. Operating with two electron beams means that a larger beam current can be used for a higher output power. Meanwhile, the electric field density of the fundamental mode is not the strongest at the center of the beam channel, so the competition of the fundamental mode is significantly suppressed. A four-section two-beam FWTWT at 140 GHz is designed to get 100 W of average power. From the simulation results, we can see that this kind of tube is unstable if the gain per section is over 11 dB, because both fundamental and band-edge modes are strongly excited. Then, another way for a stable FWTWT operation with two electron beams by loading with dielectric is also presented in this paper. The results presented here can provide a new way to obtain high power radiation at the terahertz frequency.
Autors: Yubin Gong;Hairong Yin;Lingna Yue;Zhigang Lu;Yanyu Wei;Jinjun Feng;Zhaoyun Duan;Xiong Xu;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Mar 2011, volume: 39, issue:3, pages: 847 - 851
Publisher: IEEE
 
» A 2.4 GHz Wideband Open-Loop GFSK Transmitter With Phase Quantization Noise Cancellation
Abstract:
A wide-bandwidth phase modulation transmitter with phase quantization noise cancellation technique is proposed. Unlike conventional phase-locked loop closed-loop modulation, very wide-bandwidth arbitrary phase modulation can be synthesized at the phase-locked loop output by selecting the desired phases that are generated by a phase generator. To further reduce the phase quantization noise due to the finite number of available phases, a phase quantization noise cancellation path is proposed through a second VCO control port. At least 7 dB phase noise cancellation was demonstrated using a prototype 0.18 m CMOS 2.4 GHz GFSK transmitter integrated circuit. Measurements on the prototype show that out-of-band phase quantization noise is 49 dB lower than the signal when transmitting 20 Mb/s GFSK signal and that the rms error is only 3.2%. The current consumption is 34.5 mA excluding the transmitter output buffer.
Autors: Su, P.-E.;Pamarti, S.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 615 - 626
Publisher: IEEE
 
» A 20-GHz Bipolar Latched Comparator With Improved Sensitivity Implemented in InP HBT Technology
Abstract:
A method for improving the sensitivity (or speed) of a master–slave emitter-coupled logic comparator using emitter degeneration resistors is presented. The degeneration resistors in the latching pair reduce the transistor charging time, thus allowing more time for regeneration. Improved and standard comparators were implemented using the InP/GaInAs heterojunction bipolar transistor technology and were tested at a clock rate of 20 GHz. The improved comparator exhibited better sensitivity (by a factor of 1.7) compared to the standard design. A record low-sensitivity value of 10 mV was obtained.
Autors: Kraus, S.;Kallfass, I.;Makon, R. E.;Driad, R.;Moyal, M.;Ritter, D.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 707 - 715
Publisher: IEEE
 
» A 21 fJ/Conversion-Step 100 kS/s 10-bit ADC With a Low-Noise Time-Domain Comparator for Low-Power Sensor Interface
Abstract:
This paper presents a 100 kS/s, 1.3 W, 9.3 ENOB successive approximation ADC with a time-domain comparator. The proposed time-domain comparator utilizes a differential multi-stage VCDL, resulting in a highly digital operation eliminating static power consumption. The effects of gain, noise, and offset are also investigated by detailed analysis which proves the feature of reducing the input-referred noise and offset by simply increasing the number of delay stages. For verification, the proposed ADC is fabricated in a 0.18 m CMOS. With a single supply voltage of 0.6 V, the ADC consumes 1.3 W at the maximum sampling rate of 100 kS/s. The measured ENOB is 9.3 b showing a figure of merit of 21 fJ/conversion-step.
Autors: Lee, S.-K.;Park, S.-J.;Park, H.-J.;Sim, J.-Y.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 651 - 659
Publisher: IEEE
 
» A 22–31 GHz Distributed Amplifier Based on High-Pass Transmission Lines Using 0.18 CMOS Technology
Abstract:
This letter demonstrates a 22–31 GHz CMOS distributed amplifier (DA) based on high-pass transmission lines. Unlike the low-pass DA, the circuit can be smaller since it does not need extra drain bias circuits. This DA has a maximum output power of 12 dBm, a maximum of 6.5 dBm, and a small signal gain of 6.4 dB. The chip occupies a miniature area of 0.28 including the pads and the core area is only 0.17 .
Autors: Chen, P.;Huang, P.-C.;Kuo, J.-J.;Wang, H.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2011, volume: 21, issue:3, pages: 160 - 162
Publisher: IEEE
 
» A 3–10-GHz Low-Power CMOS Low-Noise Amplifier for Ultra-Wideband Communication
Abstract:
A 90-nm CMOS low-noise amplifier (LNA) for 3–10-GHz ultra-wideband (UWB) applications is presented. The circuit adopts a single-ended dual-stage solution. The first stage is based on a current-reuse topology and performs UWB (3–10 GHz) input matching. The second stage is a cascode amplifier with resonant load to enhance gain and reverse isolation. Thanks to both the circuit solution and design approach, the LNA provides input matching, low noise, flat gain, and small group-delay variation in the UWB frequency range at minimum power consumption. The design is also conceived to cope with application issues such as low-cost off-chip interfaces and electrostatic discharge robustness. Measurements exhibit a 12.5-dB power gain in a 7.6-GHz 3-dB bandwidth, a minimum noise figure of 3 dB, a reverse isolation better than 45 dB up to 10.6 GHz, and a record small group-delay variation of 12 ps. The LNA draws 6 mA from a 1.2-V power supply.
Autors: Sapone, G.;Palmisano, G.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 678 - 686
Publisher: IEEE
 
» A 400-kHz High-Accuracy Laser Telemeter for Distributed Measurements of 3-D Profiles
Abstract:
A distributed telemeter is herein presented, which has specifically been designed for the high-speed high-resolution monitoring of trains in railway portals but can be adapted to a number of industrial and environmental applications. The system uses a single transmitter/receiver unit to feed, using optical fiber pairs, a number of measuring stations. It makes use of an ultrashort fiber laser operating at 400 kHz or, alternatively, a fiber-coupled diode laser and presents in-house developed solutions to obtain a 40-dB dynamic range, thus allowing to monitor targets within large distance/angle/color intervals. The system has been developed, tested, and installed on a train-monitoring portal in the Roma-Napoli railway, in the framework of an effort to increase the safety of trains entering tunnels in the Italian railway system.
Autors: Fumagalli, L.;Tomassini, P.;Zanatta, M.;Docchio, F.;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Mar 2011, volume: 60, issue:3, pages: 1054 - 1060
Publisher: IEEE
 
» A 60-GHz Frequency Tripler With Gain and Dynamic-Range Enhancement
Abstract:
In this paper, a single-stage 60-GHz frequency tripler is presented with -dB conversion gain in a 0.15- pseudomorphic HEMT process. When the input power backs off, unlike most of its counterparts, the conversion gain of the proposed tripler degrades very little. This feature is achieved by adjusting load impedances independently for the first and third harmonic. Besides the enhancement of the third harmonic power, substantial fundamental power is also generated without additional power consumption and is further used to drive an auxiliary diode tripler. The third harmonic power from the original field-effect transistor (FET) and the auxiliary diode tripler are combined with the conversion gain further enhanced, and the power dynamic range is also extended due to the power contributed from the auxiliary tripler. Quantitative analysis for the harmonic loading effect of the FET tripler and the bias selection for the diode tripler are conducted by using the equivalent-circuit models. The theories are verified by computer-aided design simulations and experimental results.
Autors: Kuo, N.-C.;Kao, J.-C.;Tsai, Z.-M.;Lin, K.-Y.;Wang, H.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 660 - 671
Publisher: IEEE
 
» A Bidirectional NoC (BiNoC) Architecture With Dynamic Self-Reconfigurable Channel
Abstract:
A bidirectional channel network-on-chip (BiNoC) architecture is proposed to enhance the performance of on-chip communication. In a BiNoC, each communication channel allows to be dynamically self-reconfigured to transmit flits in either direction. This added flexibility promises better bandwidth utilization, lower packet delivery latency, and higher packet consumption rate. Novel on-chip router architecture is developed to support dynamic self-reconfiguration of the bidirectional traffic flow. This area-efficient BiNoC router delivers better performance and requires smaller buffer size than that of a conventional network-on-chip (NoC). The flow direction at each channel is controlled by a channel direction control (CDC) algorithm. Implemented with a pair of finite state machines, this CDC algorithm is shown to be high performance, free of deadlock, and free of starvation. Extensive cycle-accurate simulations using synthetic and real-world traffic patterns have been conducted to evaluate the performance of the BiNoC. These results exhibit consistent and significant performance advantage over conventional NoC equipped with hard-wired unidirectional channels.
Autors: Lan, Y.-C.;Lin, H.-A.;Lo, S.-H.;Hu, Y. H.;Chen, S.-J.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Mar 2011, volume: 30, issue:3, pages: 427 - 440
Publisher: IEEE
 
» A box constrained gradient projection algorithm for compressed sensing
Abstract:
A new algorithm is presented which aims to solve problems from compressed sensing - under-determined problems where the solution vector is known a priori to be sparse. Upper bounds on the solution vector are found so that the problem can be reformulated as a box-constrained quadratic programme. A sparse solution is sought using a Barzilai-Borwein type projection algorithm. New insight into the choice of step length is provided through a study of the special structure of the underlying problem together with upper bounds on the step length. Numerical experiments are conducted and results given, comparing this algorithm with a number...
Autors: R.L., Broughton , I.D., Coope , P.F., Renaud , R.E.H., Tappenden
Appeared in: Signal Processing
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Broadband W-Band Polarization Rotator With Very Low Cross Polarization
Abstract:
We present a 82–100 GHz circular waveguide polarization rotator based on a broadband rotating half-wave retarder. The device was designed for astrophysics experiments aimed to characterize the polarization of the cosmic microwave background radiation. The device is based on a Pancharatnam recipe used in optics and has a very low intrinsic cross polarization, very flat phase response across the band and very low losses. It can be used in astronomical experiments where very high performance is required but also as a variable polarization source for instrument calibrations. The design was manufactured and then tested using a millimeter-wave vector network analyzer. The average measured RL, IL and cross polarization across a 30% bandwidth were, respectively, 38 dB, 0.27 dB, and 36.5 dB.
Autors: Pisano, G.;Melhuish, S.;Savini, G.;Piccirillo, L.;Maffei, B.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Mar 2011, volume: 21, issue:3, pages: 127 - 129
Publisher: IEEE
 
» A chip-scale particle accelerator
Abstract:
Forget for a moment about the quest to build bigger high-energy particle accelerators. At the IEEE MEMS 2011 conference in January, researchers instead explained their efforts to create a smaller one.
Autors: Calamia, J.;
Appeared in: IEEE Spectrum
Publication date: Mar 2011, volume: 48, issue:3, pages: 14 - 14
Publisher: IEEE
 
» A chopper-stabilized high-pass Delta-Sigma Modulator with reduced chopper charge injection
Abstract:
In this paper, a chopper-stabilized high-pass Delta-Sigma Modulator (DSM) is reported with experimental results. A new circuit technique to suppress the residual offset caused by the chopper switch charge injection is proposed. Enabled by an amplifier sharing architecture, the technique diverts the error charge generated by the critical chopper to the second stage of the modulator such that the resulted error becomes first-order high-pass shaped. Fabricated in a 0.18?m CMOS technology, the 2nd-order DSM realizes 82dB dynamic range over a 1kHz bandwidth while consuming 144?W from a 1.8V supply. The offset is 403?V and the flicker noise is invisible in...
Autors: Yin-Sheng, Zhao , Siu-kei, Tang , Chi-tung, Ko , Kong-pang, Pun
Appeared in: Microelectronics Journal
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Ciphertext-Only Attack Against the Cai-Cusick Lattice-Based Public-Key Cryptosystem
Abstract:
In 1998, Cai and Cusick proposed a lattice-based public-key cryptosystem based on the similar ideas of the Ajtai-Dwork cryptosystem, but with much less data expansion. However, they didn't give any security proof. In our paper, we present an efficient ciphertext-only attack which runs in polynomial time against the cryptosystem to recover the message, so the Cai-Cusick lattice-based public-key cryptosystem is not secure.
Autors: Pan, Y.;Deng, Y.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Mar 2011, volume: 57, issue:3, pages: 1780 - 1785
Publisher: IEEE
 
» A combined ion-sputtering and electron-beam annealing device for the in vacuo postpreparation of scanning probes
Abstract:
We describe the setup, characteristics, and application of an in vacuo ion-sputtering and electron-beam annealing device for the postpreparation of scanning probes (e.g., scanning tunneling microscopy (STM) tips) under ultrahigh vacuum (UHV) conditions. The proposed device facilitates the straightforward implementation of a common two-step cleaning procedure, where the first step consists of ion-sputtering, while the second step heals out sputtering-induced defects by thermal annealing. In contrast to the standard way, no dedicated external ion-sputtering gun is required with the proposed device. The performance of the described device is demonstrated by SEM micrographs and energy dispersive x-ray characterization of electrochemically etched tungsten tips prior and after postprocessing.
Autors: Eder, Georg;Schlogl, Stefan;Macknapp, Klaus;Heckl, Wolfgang M.;Lackinger, Markus;
Appeared in: Review of Scientific Instruments
Publication date: Mar 2011, volume: 82, issue:3, pages: 033701 - 033701-4
Publisher: IEEE
 
» A compact AES core with on-line error detection for FPGA applications with modest hardware resources
Abstract:
This paper presents a compact, low-cost, on-line, error-detection architecture for a 32-bit hardware implementation of the AES. The implemented AES is specially designed for FPGA-based embedded applications, since it is tuned to specific FPGA logic resources. The on-line error detection is based on parity codes. The parity prediction is implemented in the AES encryption, decryption, and key expansion process. The developed solution has been upgraded to an efficient BIST with a high fault coverage and a low hardware overhead.
Autors: Uro?, Legat , Anton, Biasizzo , Franc, Novak
Appeared in: Microprocessors and Microsystems
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Compact Wideband Antenna Integrated With a Pulse-Forming Line for Transient Pulse Radiation
Abstract:
A compact wideband antenna integrated with a pulse-forming line for transient pulse radiation is proposed in this paper. It can be used in the fields such as ultrawideband (UWB) radar, ground-penetrating radar, UWB communications, etc. This antenna is integrated with a solid-state switch and a planar Blumlein pulse-forming line. The dimension of the antenna is 300 mm × 300 mm × 3 mm. In the experiment, the switch was triggered by a laser with a wavelength of 1064 nm. The peak power of a single antenna was 14.45 MW when the applied voltage was 17 kV. A Gaussian doublet pulse with a duration of 1.5 ns and a peak-peak amplitude of 305.7 V/m at a distance of 2 m from the antenna along the main beam direction was recorded in the experiment. The measured waveform was in good agreement with the predicted one.
Autors: Yang Li;Hong-chun Yang;Shao-qiu Xiao;Ming-he Wu;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Mar 2011, volume: 39, issue:3, pages: 906 - 910
Publisher: IEEE
 
» A Comparison of High and Low Gain DMSP/OLS Satellite Images for the Study of Socio-Economic Metrics
Abstract:
The Operational Linescan System (OLS) onboard the Defense Meteorological Satellite Program (DMSP) group of satellites, unlike other passive remote sensing sensors, is capable of recording the emissions from artificial lights on the earth surface. Along with detecting light from forest fires, shipping fleets and gas flares, the OLS sensor also records the light emitted from cities at night. This paper reports on a study that uses the DMSP Operational Linescan (DMSP-OLS) images with fixed gain settings of 20 dB and 50 dB to model selected metrics used in the Indian census for the state of Maharashtra. The study firstly looks into the utility of non-composited single fixed gain radiance calibrated DMSP-OLS products for proposing a method which might help to build a surrogate method for Indian census. Several parameters are considered in this analysis, with detailed focus on population density, total population and proportion of households with electricity access for 35 districts within the state of Maharashtra. Results show that spatial scale plays an important role in selection of the images and gains. Secondly, this study provides a relative assessment of gain setting for the DMSP-OLS images in an urban Indian context. Images with a gain of 50 dB prove suitable for larger areas while those with a gain of 20 dB give better results at a smaller spatial scale. Statistical analysis and residual maps of spatial distribution of total population and population density validate the result.
Autors: Roychowdhury, K.;Jones, S. D.;Arrowsmith, C.;Reinke, K.;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Mar 2011, volume: 4, issue:1, pages: 35 - 42
Publisher: IEEE
 
» A comparison of mass parameters determination using capacitive and optical sensors
Abstract:
This paper presents a comparison study between the use of 1mm resolution capacitive and optical sensors for the determination of yarn mass parameters.A parallel plate capacitive sensor to determine yarn mass variations and a yarn diameter and hairiness determination solution using optical sensors and integrating optical signal processing based on Fourier analysis are described. As there is a high correlation between yarn diameter and yarn mass, it is possible to determine yarn mass and infer variations in yarn diameter and vice-versa. Moreover, by optically detecting the degree of yarn hairiness, one can quantify its influence on the capacitive sensor mass...
Autors: V., Carvalho , M., Belsley , R., Vasconcelos , F., Soares
Appeared in: Sensors and Actuators A: Physical
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Comparison of Symmetrical and Asymmetrical Three-Phase H-Bridge Multilevel Inverter for DTC Induction Motor Drives
Abstract:
Earlier studies have pointed out the limitations of conventional inverters, especially in high-voltage and high-power applications. In recent years, multilevel inverters are becoming increasingly popular for high-power applications due to their improved harmonic profile and increased power ratings. Several studies have been reported in the literature on multilevel inverters topologies, control techniques, and applications. However, there are few studies that actually discuss or evaluate the performance of induction motor drives associated with three-phase multilevel inverter. This paper presents then a comparison study for a cascaded H-bridge multilevel direct torque control (DTC) induction motor drive. In this case, symmetrical and asymmetrical arrangements of five- and seven-level H-bridge inverters are compared in order to find an optimum arrangement with lower switching losses and optimized output voltage quality. The carried out experiments show that an asymmetrical configuration provides nearly sinusoidal voltages with very low distortion, using less switching devices. Moreover, torque ripples are greatly reduced.
Autors: Khoucha, F.;Lagoun, M. S.;Kheloui, A.;Benbouzid , M. E. H.;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Mar 2011, volume: 26, issue:1, pages: 64 - 72
Publisher: IEEE
 
» A Compressed Sensing Approach for Modeling the Super-Resolution Near-Field Structure Disc System With a Sparse Volterra Filter
Abstract:
In this paper, we investigate the compressed sensing (CS) algorithms for modeling a super-resolution near-field structure (super-RENS) disc system with a sparse Volterra filter. It is well known that the super-RENS disc system has severe nonlinear inter-symbol interference (ISI). A nonlinear system with memory can be well described with the Volterra series. Furthermore, CS can restore sparse or compressed signals from measurements. For these reasons, we employ the CS algorithms to estimate a sparse super-RENS read-out channel. The evaluation results show that the CS algorithms can efficiently construct a sparse Volterra model for the super-RENS read-out channel and that observable nonlinear interactions take place among restricted components in the read-out channel.
Autors: Moon, W.;Im, S.;Park, T.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Mar 2011, volume: 47, issue:3, pages: 576 - 580
Publisher: IEEE
 
» A Continuous Time Multi-Bit ADC Using Time Domain Quantizer and Feedback Element
Abstract:
A third-order CT ADC that replaces the multi-bit quantizer and feedback DAC by a pulsewidth modulation (PWM) generator and time-to-digital converter (TDC) is implemented in 65 nm CMOS technology. The TDC provides a 50-level binary output code and a time-quantized feedback pulse to the modulator. It is shown that the TDC can achieve 11 bit linearity in time steps without calibration or dynamic element matching. The modulator achieves 68 dB DR in 20 MHz BW, consumes 10.5 mW and occupies 0.15 .
Autors: Dhanasekaran, V.;Gambhir, M.;Elsayed, M. M.;Sanchez-Sinencio, E.;Silva-Martinez, J.;Mishra, C.;Chen, L.;Pankratz, E. J.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 639 - 650
Publisher: IEEE
 
» A Continuous-Time, Discrete-State Method for Simulating the Dynamics of Biochemical Systems
Abstract:
Computational systems biology is largely driven by mathematical modeling and simulation of biochemical networks, via continuous deterministic methods or discrete event stochastic methods. Although the deterministic methods are efficient in predicting the macroscopic behavior of a biochemical system, they are severely limited by their inability to represent the stochastic effects of random molecular fluctuations at lower concentration. In this work, we have presented a novel method for simulating biochemical networks based on a deterministic solution with a modification that permits the incorporation of stochastic effects. To demonstrate the feasibility of our approach, we have tested our method on three previously reported biochemical networks. The results, while staying true to their deterministic form, also reflect the stochastic effects of random fluctuations that are dominant as the system transitions into a lower concentration. This ability to adapt to a concentration gradient makes this method particularly attractive for systems biology-based applications.
Autors: Sabnis, A.;Harrison, R.W.;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Mar 2011, volume: 8, issue:2, pages: 335 - 341
Publisher: IEEE
 
» A Cooperative Beamforming Scheme in MIMO Relay Broadcast Channels
Abstract:
We consider relay broadcast channels (RBCs) with multiple antennas at all nodes. A practical linear precoding, relaying and combining scheme is proposed. Under an overall power constraint, we derive the optimal power allocation solution in a closed form. A low complexity beamforming vector optimization algorithm is proposed to maximize the effective channel gains and improve the system performance. Simulation results are presented for various channel configurations, which show that the proposed cooperative beamforming algorithm achieves performance very close to that of the exhaustive search algorithm but with a much lower complexity, and the maximum diversity gain is always attained.
Autors: Zhou, Zhendong;Vucetic, Branka;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Mar 2011, volume: 10, issue:3, pages: 940 - 947
Publisher: IEEE
 
» A Cost-Effective High-Efficiency Power Conditioner With Simple MPPT Control Algorithm for Wind-Power Grid Integration
Abstract:
In this paper, a novel grid integration system for a variable-speed wind turbine using an interior permanent-magnet synchronous generator (IPMSG) is developed. The power conditioner system (PCS) consists of a series-type 12-pulse uncontrolled diode rectifier powered by a phase-shifting transformer and then cascaded to a pulsewidth-modulated (PWM) voltage source inverter. The active current of the grid-side PWM inverter is only controlled to follow the optimal active current reference which is determined by using a simple maximum power point tracking (MPPT) control strategy. The MPPT algorithm requires only three sensors in order to track the maximum power of the wind turbine. The most significant advantage of the proposed system is that the passive filter together with a series-type 12-pulse rectifier provides high efficiency by compensating the power factor angle of the IPMSG and suppresses distortions presented in the IPMSG voltages and currents. The laboratory results indicate that the proposed construction and scheme are simple, cheap, and efficient.
Autors: Nishida, K.;Ahmed, T.;Nakaoka, M.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Mar 2011, volume: 47, issue:2, pages: 893 - 900
Publisher: IEEE
 
» A Cost-Efficient L1–L2 Multicore Interconnect: Performance, Power, and Area Considerations
Abstract:
Processor manufacturers use advances in manufacturing technologies to increase the number of cores on chip in order to scale performance in a cost-efficient manner. As the number of cores scales up, not all cores can be directly connected to the main memory and there is a need for hierarchy, for example, by arranging them in clusters that share L2 caches. This paper focuses on designing cost-efficient L1–L2 interconnects. We discuss performance and power- and area-consumption considerations for a real processor designed in 45-nm technology. We explain the architectures and heuristics developed, including a smart floorplan with instance flips to address interconnect latency, customized decentralized arbitration schemes tailored per transaction type, and heterogeneous Vt device assignment to reduce overall power consumption, taking into account the expected switching factors. These and other methods worked together to achieve high throughput in a power-efficient interconnect that consumes less than 3% of the compute cluster area.
Autors: Golander, A.;Levison, N.;Heymann, O.;Briskman, A.;Wolski, M. J.;Robinson, E. F.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Mar 2011, volume: 58, issue:3, pages: 529 - 538
Publisher: IEEE
 
» A Cross-Layer Approach Handling Link Asymmetry for Wireless Mesh Access Networks
Abstract:
In wireless mesh access networks working in an ad hoc model, link asymmetry exists because of the heterogeneous transmission range of mesh clients and mesh routers. In such networks, several challenges, including the unidirectional link problem, heterogeneous hidden problem, and heterogeneous exposed problem, can dramatically degrade network performance. In this paper, we develop a cross-layer approach for mesh access networks to simultaneously address these challenges and improve network performance. The main ideas of our approach are to eliminate the unidirectional link at the network layer and design novel handshake and channel reservation mechanisms at the medium-accesscontrol (MAC) layer using topological information collected in the network layer. Via a combination of theoretical analysis and extensive evaluation, we validate that our approach can achieve better performance with lower cost in comparison with existing approaches.
Autors: Huang, Y.;Yang, X.;Yang, S.;Yu, W.;Fu, X.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2011, volume: 60, issue:3, pages: 1045 - 1058
Publisher: IEEE
 
» A crowd of quantum entanglements
Abstract:
In a flurry of research reports during the past six months, physicists have proven that silicon, the basis of computers today, could also be the best platform for tomorrow's quantum computers.
Autors: Das, S.R.;
Appeared in: IEEE Spectrum
Publication date: Mar 2011, volume: 48, issue:3, pages: 18 - 18
Publisher: IEEE
 
» A database system for power systems customers and energy efficiency programs
Abstract:
 Research highlights: ? Database for power systems and customers. ? Study of customers' energy behavior. ? Validation of efficiency measures.

Autors: In this paper the design and development of a database for the registration of power utilities' customers and their energy behavior are described. The database also includes the customers' devices and buildings, their demand curves, their tariffs, th
Appeared in: International Journal of Electrical Power & Energy Systems
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A delay decomposition approach to filter design for stochastic systems with time-varying delay?
Abstract:
This paper investigates the problem of filter design for a class of stochastic systems with time-varying delay. The addressed problem is the design of a full order linear filter such that the error system is asymptotically mean-square stable and a prescribed performance is satisfied. In order to develop a less conservative filter design, a new Lyapunov-Krasovskii functional (LKF) is constructed by decomposing the delay interval into multiple equidistant subintervals, and a new integral inequality is established in the stochastic setting. Then, based on the LKF and integral inequality, the delay-dependent conditions for the existence of filters are...
Autors: Huai-Ning, Wu , Jun-Wei, Wang , Peng, Shi
Appeared in: Automatica
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A DFIG Sensorless Rotor-Position Detector Based on a Hysteresis Controller
Abstract:
A simple sensorless method for the detection of the mechanical rotor position of the wound-rotor induction machine in order to implement stator-flux orientation is described and evaluated in this paper. The method is based on the phase comparison of the actual and the estimated rotor currents using the classical model of the machine. It can be conceptually implemented in the rotor or in the stator reference frames. It has some similarity to the model reference adaptive system methodology, but uses a hysteresis comparator instead of a proportional integral (PI) controller. In this way, the method does not need parameter determination for the controllers and shows a considerable independence of parameter uncertainties. Simulation and experimental results show that the method is appropriate for the vector control of the doubly fed induction generator (DFIG) because it leads to the decoupling of active and reactive power chains. It is also appropriate for the control of the DFIG in transients like those when voltage dips occur.
Autors: Marques, G. D.;Pires, V. F.;Sousa, S.;Sousa, D. M.;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Mar 2011, volume: 26, issue:1, pages: 9 - 17
Publisher: IEEE
 
» A Digitally Testable Modulator Using the Decorrelating Design-for-Digital-Testability
Abstract:
This paper demonstrates a digitally testable second-order modulator. The modulator under test (MUT) employs the decorrelating design-for-digital-testability scheme to provide two operation modes: the normal mode and the digital test mode. In the digital test mode, the input switched-capacitor network of the modulator is reconfigured as two sub-digital-to-charge converters (sub-DCCs). Each of the sub-DCCs accepts a modulated bit-stream as its test stimulus. By repetitively inputting the DCCs with the same modulated bit-stream but with different delays, the DCCs incorporates with the integrator to generate the analog stimulus in the digital test mode. The analog stimulus is analogous to the result of filtering the bit-stream with a two-nonzero-term FIR decorrelating term. Consequently, the MUT suffers less from the undesired shaped noise of the digital stimuli, and achieves better digital test accuracy. Measurement results show that the digital tests present a peak signal-to-noise-and-distortion ratio (SNDR) of 80.1 dB at an oversampling ratio of 128. The SNDR results of the digital tests differ from their conventional analog counterparts by no more than 2 dB except for the 3.2 dBFS test. The analog hardware overhead of the MUT only consists of 13 switches.
Autors: Liang, S.-C.;Hong, H.-C.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Mar 2011, volume: 19, issue:3, pages: 503 - 507
Publisher: IEEE
 
» A Direct Determination of the Orientation Parameters in the Collinearity Equations
Abstract:
Collinearity equations provide an essential basis for photogrammetry applications in which the observables in the image and object spaces are related within an imaging system. It has been routine practice to determine the exterior orientation parameters in these equations using observed control points. However, due to the nonlinearity of the collinearity equations, an appropriate set of approximate values for the orientation parameters must be previously given in order to initiate the parameter estimation procedure and result in a converged solution. In this letter, a quick algorithm for determining the orientation parameters is proposed based on the newly developed noniterative solutions to linear transformations technique. This algorithm does not require auxiliary attitude information (e.g., from inertial navigation system (INS) measurements or trajectory data), and a direct solution for the orientation parameters can be obtained using a closed-form expression. It is then demonstrated, in a real case study, that the proposed approach is capable of producing a set of orientation parameter estimates with a sufficient level of quality to support rigorous image analyses.
Autors: Han, J.-Y.;Guo, J.;Chou, J.-Y.;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Mar 2011, volume: 8, issue:2, pages: 313 - 316
Publisher: IEEE
 
» A Distributed Controller for Managing Speculative Functional Units in High Level Synthesis
Abstract:
Speculative functional units (SFUs) are arithmetic functional units that operate using a predictor for the carry signal. The carry prediction helps to shorten the critical path of the functional unit. The average case performance of these units is determined by the hit rate of the prediction. In case of mispredictions, the SFUs need to be coordinated by the datapath control mechanism to perform corrections and to maintain the datapath in the correct state. Devising a control mechanism for correcting mispredictions without adversely impacting overall performance is the most important challenge. In this paper, we present techniques for designing a datapath controller for seamless deployment of SFUs in high level synthesis. We have developed two techniques based on two main control paradigms: centralized and distributed control. The centralized approach stops the execution of the entire datapath for each misprediction and resumes execution once the correct value of the carry is known. The distributed approach decouples the functional unit suffering from the misprediction from the rest of the datapath. Hence, it allows the remainder of the functional units to carry on execution and be at different scheduling states at different times. We tested datapaths utilizing both linear structures and logarithmic structures for speculative arithmetic functional units. Our results show that it is possible to reduce execution time by as much as 38% (33% on average) for linear structures and by as much as 37.2% (25% on average) for logarithmic structures.
Autors: Del Barrio, A. A.;Memik, S. O.;Molina, M. C.;Mendias, J. M.;Hermida, R.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Mar 2011, volume: 30, issue:3, pages: 350 - 363
Publisher: IEEE
 
» A Distributed Key Management Framework with Cooperative Message Authentication in VANETs
Abstract:
In this paper, we propose a distributed key management framework based on group signature to provision privacy in vehicular ad hoc networks (VANETs). Distributed key management is expected to facilitate the revocation of malicious vehicles, maintenance of the system, and heterogeneous security policies, compared with the centralized key management assumed by the existing group signature schemes. In our framework, each road side unit (RSU) acts as the key distributor for the group, where a new issue incurred is that the semi-trust RSUs may be compromised. Thus, we develop security protocols for the scheme which are able to detect compromised RSUs and their colluding malicious vehicles. Moreover, we address the issue of large computation overhead due to the group signature implementation. A practical cooperative message authentication protocol is thus proposed to alleviate the verification burden, where each vehicle just needs to verify a small amount of messages. Details of possible attacks and the corresponding solutions are discussed. We further develop a medium access control (MAC) layer analytical model and carry out NS2 simulations to examine the key distribution delay and missed detection ratio of malicious messages, with the proposed key management framework being implemented over 802.11 based VANETs.
Autors: Hao, Yong;Cheng, Yu;Zhou, Chi;Song, Wei;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Mar 2011, volume: 29, issue:3, pages: 616 - 629
Publisher: IEEE
 
» A Distribution-Based Systems Reliability Model Under Extreme Shocks and Natural Degradation
Abstract:
Degradation, and shock are two common mechanisms accounting for product failures. This paper presents a convenient means of capturing both shock and degradation in a single model when the extent of degradation and the magnitude of shocks are not observable, but only the failure times and the corresponding failure modes are recorded. We assume that the lifetime of a degradation-oriented failure, which is regarded as some initial random resource, belongs to some distribution family. Shocks arrive according to a non-homogeneous Poisson process, and the destructive probability depends on the transformed remaining resource of the system. Under these assumptions, we propose the single failure time model, and the recurrent event model. This study complements the well-known Brown-Proschan model. The single failure time model has successfully been applied to a real time data set. We also conduct a simulation study to examine the accuracy of our model.
Autors: Ye, Z. S.;Tang, L. C.;Xu, H. Y.;
Appeared in: IEEE Transactions on Reliability
Publication date: Mar 2011, volume: 60, issue:1, pages: 246 - 256
Publisher: IEEE
 
» A dual analyzer for real-time impedance and noise spectroscopy of nanoscale devices
Abstract:
This paper introduces a simple portable dual analyzer which allows real-time ac-impedance measurements and noise spectroscopic analysis simultaneously, employing one or two data acquisition systems together with a low noise current-to-voltage preamplifier. The input signal composed of numerous selected frequencies of sinusoidal voltages with a dc bias was applied to a device under the test (DUT): single walled carbon nanotube field effect transistors (SWCNT-FETs). Each frequency component, ranging from 1 to 46.4 kHz, was successfully mapped to a Nyquist plot using the background of the electrical noise power spectrum. It is, thus, clearly demonstrated that this dual analyzer enables the real-time ac-impedance analysis and the frequency response of the carrier transport in the SWCNT-FETs as a DUT.
Autors: Joo, Min-Kyu;Kang, Pilsoo;Kim, Yongha;Kim, Gyu-Tae;Kim, Sangtae;
Appeared in: Review of Scientific Instruments
Publication date: Mar 2011, volume: 82, issue:3, pages: 034702 - 034702-5
Publisher: IEEE
 
» A Dual-Band GNSS RF Front End With a Pseudo-Differential LNA
Abstract:
This brief presents the design and the implementation of a dual-band radio-frequency (RF) front end for global navigation satellite system (GNSS) receivers. The dual-band RF front end is composed of a pseudo-differential low-noise amplifier (LNA), down-conversion mixers, and programmable gain amplifiers (PGAs), and can be configured to operate at 1.2 and 1.57 GHz, respectively. The pseudo-differential LNA incorporates an active single-ended-to-differential conversion using capacitive coupling compensation for an improved phase and amplitude imbalance. The high-linearity PGA has a tunable gain range of 18 dB with a 6-dB gain step and a 0.2-dB gain ripple across a 30-MHz bandwidth. The proposed RF front end achieves a maximum voltage gain of 68/65 dB, a noise figure of 2.4/2.6 dB, and an input-referred 1-dB compression point of 42/ 39 dBm at the 1.2-/1.57-GHz bands. The receiver draws 10 mA from a 1.8-V power supply. The RF front end is implemented in a 0.18- CMOS process, occupying a die area of .
Autors: Wu, J.;Jiang, P.;Chen, D.;Zhou, J.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Mar 2011, volume: 58, issue:3, pages: 134 - 138
Publisher: IEEE
 
» A Dynamic Hybrid Projection Approach for Improved Wi-Fi Location Fingerprinting
Abstract:
Projection techniques have been used in Wi-Fi location fingerprinting systems to improve positioning accuracy. However, environmental dynamics present challenges to projection design. Furthermore, current projection-optimization techniques used in positioning, such as principal component analysis (PCA) and multiple discriminant analysis (MDA), have both advantages and limitations. This paper proposes a dynamic hybrid projection (DHP) technique for improved Wi-Fi localization, in which the projection is dynamically determined by simultaneously exploiting the complementary advantages of PCA and MDA while avoiding their unfavorable properties. The main contribution of this work is twofold: First, this study provides a novel formulation of a hybrid projection, which embeds the discriminative power into PCA and compensates for the two numerical problems of MDA in a unified framework. Second, DHP dynamically adjusts the hybrid mechanism with additional information, regarding the online-input region. That is, the proposed projection is input dependent, whereas traditional projections are fixed after training. This study applies the proposed algorithm to location fingerprinting in a realistic indoor Wi-Fi environment. On-site experimental results demonstrate that DHP outperforms static projection schemes, reducing the 50th and 67th percentile localization errors by 24.73%–30% and 18.18%–19.51%, respectively, compared with PCA and MDA.
Autors: Fang, S.-H.;Wang, C.-H.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Mar 2011, volume: 60, issue:3, pages: 1037 - 1044
Publisher: IEEE
 
» A Dynamic Resource Management and Scheduling Environment for Embedded Multimedia and Communications Platforms
Abstract:
We present a framework, OpenCLosE, for dynamic resource management and scheduling of applications written in open compute language (OpenCL) for heterogeneous multimedia and graphics platforms, such as those found in multimedia smartphones and automotive infotainment clusters. We describe the design of a resource manager and master scheduler for the OpenCLosE environment, that allows efficient realization of multiple applications within a multitasked platform.
Autors: Bahga, A.;Madisetti, V. K.;
Appeared in: IEEE Embedded Systems Letters
Publication date: Mar 2011, volume: 3, issue:1, pages: 24 - 27
Publisher: IEEE
 
» A fast grasp synthesis method for online manipulation
Abstract:
 Research highlights: ? We develop algorithms for grasping and manipulation with mechanical hands.? The grasp optimization problem is solved using a genetic approach.? A method for the computation of a fingertip force is detailed.? Simulation and experimental results with a mechanical hand are given in the paper.

Autors: This paper presents a new method for solving the grasp optimization problem by a multi-finger robotic hand; this method allows gripping an object using three articulated fingers, in order to manipulate it later. Online grasp is not achieved yet in th
Appeared in: Robotics and Autonomous Systems
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Fast Signal Timing Algorithm for Individual Oversaturated Intersections
Abstract:
In this paper, we propose a fast greedy search algorithm for optimal single-cycle signal timing at individual oversaturated intersections. We illustrate the efficiency of the algorithm with a numerical example in the literature.
Autors: Zhao, L.;Peng, X.;Li, L.;Li, Z.;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Mar 2011, volume: 12, issue:1, pages: 280 - 283
Publisher: IEEE
 
» A FinFET Memory with Remote Carrier Trapping in ONO Buried Insulator
Abstract:
Advanced FinFETs fabricated on SiO2-Si3N4-SiO2 (ONO) buried insulator are investigated for flash memory applications. Systematic measurements reveal that the Si3N4 layer can easily trap charges by applying appropriate drain bias. The amount of trapped/detrapped charges in the buried nitride is sensed remotely by gate coupling through the variation of the drain current flowing at the front-gate interface. The front-channel threshold voltage variation, ?VTHF, resulting from the charge trapping, induces a hysteresis "window" proper to non-volatile memory devices. Finally, our measurements highlight the geometrical parameter effects on the memory window size.
Autors: S.-J., Chang , M., Bawedin , W., Xiong , S.C., Jean , J.-H., Lee , ...
Appeared in: Microelectronic Engineering
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Foreground/Background Separation Framework for Interpreting Polarimetric SAR Images
Abstract:
In this letter, we present a novel foreground/background separation (FBS) framework for interpreting polarimetric synthetic aperture radar (PolSAR) images. The FBS framework takes the spatial relations between pixels into consideration and incorporates the advantages of pairwise dissimilarity-based grouping schemes. The FBS method can separate specific targets and objects from the background, which is essential in an interpretation system. Multiple FBS operations can be integrated to interpret PolSAR images, flexibly fusing various inherent features of PolSAR data. Several PolSAR data sets are used to verify the proposed approach.
Autors: Liu, B.;Wang, H.;Wang, K.;Liu, X.;Yu, W.;
Appeared in: IEEE Geoscience and Remote Sensing Letters
Publication date: Mar 2011, volume: 8, issue:2, pages: 288 - 292
Publisher: IEEE
 
» A Framework for Semisupervised Feature Generation and Its Applications in Biomedical Literature Mining
Abstract:
Feature representation is essential to machine learning and text mining. In this paper, we present a feature coupling generalization (FCG) framework for generating new features from unlabeled data. It selects two special types of features, i.e., example-distinguishing features (EDFs) and class-distinguishing features (CDFs) from original feature set, and then generalizes EDFs into higher-level features based on their coupling degrees with CDFs in unlabeled data. The advantage is: EDFs with extreme sparsity in labeled data can be enriched by their co-occurrences with CDFs in unlabeled data so that the performance of these low-frequency features can be greatly boosted and new information from unlabeled can be incorporated. We apply this approach to three tasks in biomedical literature mining: gene named entity recognition (NER), protein-protein interaction extraction (PPIE), and text classification (TC) for gene ontology (GO) annotation. New features are generated from over 20 GB unlabeled PubMed abstracts. The experimental results on BioCreative 2, AIMED corpus, and TREC 2005 Genomics Track show that 1) FCG can utilize well the sparse features ignored by supervised learning. 2) It improves the performance of supervised baselines by 7.8 percent, 5.0 percent, and 5.8 percent, respectively, in the tree tasks. 3) Our methods achieve 89.1, 64.5 F-score, and 60.1 normalized utility on the three benchmark data sets.
Autors: Yanpeng Li;Xiaohua Hu;Hongfei Lin;Zhiahi Yang;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Mar 2011, volume: 8, issue:2, pages: 294 - 307
Publisher: IEEE
 
» A frequency sextupling scheme for high-quality optical millimeter-wave signal generation without optical filter
Abstract:
? The theoretical analysis and simulation verification of the proposed frequency sextupling scheme for high-quality optical mm-wave signal generation without optical filter are both presented. ? The relation between the extinction of the integrated Mach-Zehnder modulator (IMZM) consisted three sub-MZMs and single MZM is derived. ? Optical sideband suppression ratio (OSSR) for the IMZM with higher extinction ratio is more susceptible to nonideal phase difference of RF drive signal between two sub-MZMs. ? The imperfect extinction ratio of IMZM on OSSR is also investigated.

Autors: Based on a laser with an integrated Mach-Zehnder modulator (IMZM), a novel frequency sextupling scheme is proposed for the millimeter-wave (mm-wave) signal generation in radio over fiber system. Theoretical analysis is presented to implement the two-
Appeared in: Optical Fiber Technology
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A GaAs MMIC-based coupling RF MEMS power sensor with both detection and non-detection states
Abstract:
This paper first presents the detection and non-detection function of an inline RF MEMS power sensor by employing two shunt capacitive MEMS switch structures. It solves a problem that regardless of whether the power sensor needed to detect the power, a certain microwave power will always be detected, which results in the unnecessary power loss. This power sensor is based on sensing a certain percentage of the incident microwave power coupled by a MEMS membrane. The effect of an impedance matching structure for improving microwave characteristics, a capacitance compensating structure for obtaining the wideband response, and the two shunt capacitive...
Autors: Zhiqiang, Zhang , Xiaoping, Liao , Lei, Han , Yinsheng, Cheng
Appeared in: Sensors and Actuators A: Physical
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Gaussian Mixture Filter for Range-Only Tracking
Abstract:
Range-only tracking problems arise in extended data collection for inverse synthetic radar applications, robotics, navigation and other areas. For such problems, the conditional density of the state variable given the measurement history is multi-modal or exhibits curvature, even in seemingly benign scenarios. For this reason, the use of extended Kalman filter (EKF) and other nonlinear filtering techniques based on Gaussian approximations can result in inaccurate estimates. We introduce a new filter for such tracking problems in two dimensions called the Gaussian mixture range-only filter (GMROF), which generates Gaussian mixture approximations to the conditional densities. The filter equations are derived by analytic techniques based on the specific nonlinearities of range-only tracking. A slight modification of the standard measurement process model, “noise before nonlinearity,” is used to simplify the moment calculations. Implementation requires, at each step, the fitting of a low order Gaussian mixture to a simple exponentiated trigonometric function of a scalar variable. Simulations involving scenarios from earlier comparative studies indicate that the GMROF consistently outperformed the EKF, and achieved the accuracy of particle filters while significantly reducing the computational cost.
Autors: Clark, J.M.C.;Kountouriotis, P.A.;Vinter, R.B.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Mar 2011, volume: 56, issue:3, pages: 602 - 613
Publisher: IEEE
 
» A General Model for Start-Up Demonstration Tests
Abstract:
The commonly known consecutive successes total failures (CSTF) start-up demonstration test procedure is generalized to a total successes consecutive successes total failures consecutive failures (TSCSTFCF) procedure. Accordingly, a unit under test is accepted when either a total number of successful tests or a specified number of consecutive successes of tests are observed before both a total number of failures and any run of specified length of failures; otherwise the unit is rejected. The waiting time until termination (the length of the set of tests) of the general procedure is evaluated. A correct choice of parameters (e.g. the number of successes required for acceptance, or the length of a run of failures causing rejection) may yield a significantly shorter waiting time than that of the relevant CSTF procedure. Also, the new procedure is less sensitive to parameter changes, which is an obvious improvement in case the parameter values are miss-specified. We provide interval confidence bounds for the estimation of the reliability for the start-up demonstration test, which is based on maximum likelihood estimators. Then, we determine the minimum sample size needed in a demonstration test to achieve a certain precision of this reliability at a specified confidence level.
Autors: Gera, A. E.;
Appeared in: IEEE Transactions on Reliability
Publication date: Mar 2011, volume: 60, issue:1, pages: 295 - 304
Publisher: IEEE
 
» A Generalized Additional Boundary Condition for Mushroom-Type and Bed-of-Nails-Type Wire Media
Abstract:
An additional boundary condition (ABC) for mushroom or bed-of-nails metamaterials is generalized for thin 3-D or 2-D material patches or ground planes. It is shown that the usual ABC necessary for the homogenization of these wire-medium metamaterials fails for thin imperfect conductors, and a generalization is presented based on charge conservation. The new ABC leads to results that are in good agreement with full-wave simulations.
Autors: Yakovlev, A. B.;Padooru, Y. R.;Hanson, G. W.;Mafi, A.;Karbasi, S.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 527 - 532
Publisher: IEEE
 
» A Generalized Technique of Modeling, Analysis, and Control of a Matrix Converter Using SVD
Abstract:
In this paper, a new simple and complete technique of modeling and analysis of a matrix converter is presented based on the singular value decomposition (SVD) of modulation matrix. The proposed modeling method yields a new limitation between the matrix converter gain and its input power factor, which is more relaxed as compared to the limits reported so far in the literature. The SVD of the modulation matrix leads to a unified modulation technique which achieves the full capability of a matrix converter. It is shown that this approach is general and all other modulation methods established for a matrix converter are specific cases of this technique. The proposed modulation method can be used to obtain the maximum reactive power in the input of a matrix converter in applications such as wind turbine and microturbine generators, where the input reactive power control is necessary.
Autors: Hojabri, H.;Mokhtari, H.;Chang, L.;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Mar 2011, volume: 58, issue:3, pages: 949 - 959
Publisher: IEEE
 
» A Genetic Optimization Approach for Isolating Translational Efficiency Bias
Abstract:
The study of codon usage bias is an important research area that contributes to our understanding of molecular evolution, phylogenetic relationships, respiratory lifestyle, and other characteristics. Translational efficiency bias is perhaps the most well-studied codon usage bias, as it is frequently utilized to predict relative protein expression levels. We present a novel approach to isolating translational efficiency bias in microbial genomes. There are several existent methods for isolating translational efficiency bias. Previous approaches are susceptible to the confounding influences of other potentially dominant biases. Additionally, existing approaches to identifying translational efficiency bias generally require both genomic sequence information and prior knowledge of a set of highly expressed genes. This novel approach provides more accurate results from sequence information alone by resisting the confounding effects of other biases. We validate this increase in accuracy in isolating translational efficiency bias on 10 microbial genomes, five of which have proven particularly difficult for existing approaches due to the presence of strong confounding biases.
Autors: Raiford, D.W.;Krane, D.E.;Doom, T.E.;Raymer, M.L.;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Mar 2011, volume: 8, issue:2, pages: 342 - 352
Publisher: IEEE
 
» A Geometric Method for Optimal Design of Color Filter Arrays
Abstract:
A color filter array (CFA) used in a digital camera is a mosaic of spectrally selective filters, which allows only one color component to be sensed at each pixel. The missing two components of each pixel have to be estimated by methods known as demosaicking. The demosaicking algorithm and the CFA design are crucial for the quality of the output images. In this paper, we present a CFA design methodology in the frequency domain. The frequency structure, which is shown to be just the symbolic DFT of the CFA pattern (one period of the CFA), is introduced to represent images sampled with any rectangular CFAs in the frequency domain. Based on the frequency structure, the CFA design involves the solution of a constrained optimization problem that aims at minimizing the demosaicking error. To decrease the number of parameters and speed up the parameter searching, the optimization problem is reformulated as the selection of geometric points on the boundary of a convex polygon or the surface of a convex polyhedron. Using our methodology, several new CFA patterns are found, which outperform the currently commercialized and published ones. Experiments demonstrate the effectiveness of our CFA design methodology and the superiority of our new CFA patterns.
Autors: Hao, P.;Li, Y.;Lin, Z.;Dubois, E.;
Appeared in: IEEE Transactions on Image Processing
Publication date: Mar 2011, volume: 20, issue:3, pages: 709 - 722
Publisher: IEEE
 
» A Global Spatial Similarity Optimization Scheme to Track Large Numbers of Dendritic Spines in Time-Lapse Confocal Microscopy
Abstract:
Dendritic spines form postsynaptic contact sites in the central nervous system. The rapid and spontaneous morphology changes of spines have been widely observed by neurobiologists. Determining the relationship between dendritic spine morphology change and its functional properties such as memory learning is a fundamental yet challenging problem in neurobiology research. In this paper, we propose a novel algorithm to track the morphology change of multiple spines simultaneously in time-lapse neuronal images based on nonrigid registration and integer programming. We also propose a robust scheme to link disappearing-and-reappearing spines. Performance comparisons with other state-of-the-art cell and spine tracking algorithms, and the ground truth show that our approach is more accurate and robust, and it is capable of tracking a large number of neuronal spines in time-lapse confocal microscopy images.
Autors: Li, Q.;Deng, Z.;Zhang, Y.;Zhou, X.;Valentin Nagerl, U.;Wong, S. T. C.;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Mar 2011, volume: 30, issue:3, pages: 632 - 641
Publisher: IEEE
 
» A Gray Level Weighting Method to Reduce Optical Aberration Effect in Holographic Data Storage System
Abstract:
An alignment method for holographic data storage system (HDSS) is proposed in this paper. Due to several types of noises encountered in the HDSS, the signal-to-noise ratio (SNR) is degraded. Errors can be corrected using a channel code for some sorts of noise, while it may require a high quality optical system to reduce the error probability for the other types of noise. A checkerboard pattern is proposed using intensity weighting to find the fiducial points, which could work in a lower SNR system and thus reduce the error likelihood effectively. Reed-solomon (RS) code and oversampling are both made available in the HDSS. As a consequence, the aberration effects are eliminated using the fiducial points, leading to a low SNR system clear of errors after performing decoding. The lowest SNR system is out of error-free recovery condition, so that all the alignment methods proposed in this paper could not reduce the aberration effects to restore the images into the original data.
Autors: Ou-Yang, M.;Chen, Y.-T.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Mar 2011, volume: 47, issue:3, pages: 546 - 550
Publisher: IEEE
 
» A Grounded MoM-Based Spatial Green's Function Technique for the Analysis of Multilayered Circuits in Rectangular Shielded Enclosures
Abstract:
A continuous counterpart of the spatial images technique is proposed for the computation of the multilayered boxed Green's functions and their derivatives. The method employs a set of auxiliary linear distribution of sources to effectively impose the potential boundary conditions along the whole cavity contour. The imposition of these boundary conditions leads to a set of integral equations (IEs), on the unknown distributions of the auxiliary sources, which are solved by applying a method of moments approach. A convergence/efficiency study, related to the test and basis functions choice, is then presented and discussed. The technique is combined with the use of dynamic ground planes generating mirror basis functions, which completely remove any singular instability. Finally, the computed Green's functions are included into a mixed-potential IE formulation for the accurate and very fast analysis of practical multilayered shielded circuits. The proposed technique does not suffer from any convergence issue and it is extremely competitive in terms of accuracy and efficiency as compared to other methods known to the authors.
Autors: Gomez-Diaz, J. S.;Garcia-Vigueras, M.;Alvarez-Melcon, A.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 533 - 541
Publisher: IEEE
 
» A hierarchy of LMI inner approximations of the set of stable polynomials?
Abstract:
Exploiting spectral properties of symmetric banded Toeplitz matrices, we describe simple sufficient conditions for the positivity of a trigonometric polynomial formulated as linear matrix inequalities (LMIs) in the coefficients. As an application of these results, we derive a hierarchy of convex LMI inner approximations (affine sections of the cone of positive definite matrices of size m) of the nonconvex set of Schur stable polynomials of given degree n
Autors: Mustapha, Ait Rami , Didier, Henrion
Appeared in: Automatica
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A high-efficiency DC-DC buck converter for sub-2×VDD power supply
Abstract:
This paper presents a DC-DC step-down converter, which can accommodate the range of power supply voltage from VDD to sub-2×VDD. By utilizing stacked power MOSFETs, a voltage level converter, a detector and a controller, the proposed design is realized by a typical 1P6M CMOS process without using any high voltage process to resolve gate-oxide reliability and leakage current problems. The core area of the proposed design is less than 0.184mm2, while the power supply range is up to 5V. Since the internal reference voltage is 1.0V, it can increase the output regulation range. The proposed design attains very high...
Autors: Chua-Chin, Wang , Chih-Lin, Chen , Gang-Neng, Sung , Ching-Lin, Wang
Appeared in: Microelectronics Journal
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A high-power spatial filter for Thomson scattering stray light reduction
Abstract:
The Thomson scattering diagnostic on the High Beta Tokamak-Extended Pulse (HBT-EP) is routinely used to measure electron temperature and density during plasma discharges. Avalanche photodiodes in a five-channel interference filter polychromator measure scattered light from a 6 ns, 800 mJ, 1064 nm Nd:YAG laser pulse. A low cost, high-power spatial filter was designed, tested, and added to the laser beamline in order to reduce stray laser light to levels which are acceptable for accurate Rayleigh calibration. A detailed analysis of the spatial filter design and performance is given. The spatial filter can be easily implemented in an existing Thomson scattering system without the need to disturb the vacuum chamber or significantly change the beamline. Although apertures in the spatial filter suffer substantial damage from the focused beam, with proper design they can last long enough to permit absolute calibration.
Autors: Levesque, J. P.;Litzner, K. D.;Mauel, M. E.;Maurer, D. A.;Navratil, G. A.;Pedersen, T. S.;
Appeared in: Review of Scientific Instruments
Publication date: Mar 2011, volume: 82, issue:3, pages: 033501 - 033501-5
Publisher: IEEE
 
» A High-Yield -Based Unipolar Resistive RAM Employing Ni Electrode Compatible With Si-Diode Selector for Crossbar Integration
Abstract:
In this letter, a resistive random access memory based on Ni electrode/ dielectric/ Si substrate structure is demonstrated, which can be integrated with Si diode as selector for application in crossbar architecture. The unipolar device shows well-behaved memory performance, such as high on/off resistance ratio , good retention characteristics at ), satisfactory pulse switching endurance , and a fast programming speed of about 50 ns. More importantly, it also exhibits almost 100% device yield on a 6-in wafer.
Autors: Tran, X. A.;Yu, H. Y.;Yeo, Y. C.;Wu, L.;Liu, W. J.;Wang, Z. R.;Fang, Z.;Pey, K. L.;Sun, X. W.;Du, A. Y.;Nguyen, B. Y.;Li, M. F.;
Appeared in: IEEE Electron Device Letters
Publication date: Mar 2011, volume: 32, issue:3, pages: 396 - 398
Publisher: IEEE
 
» A highly modular beamline electrostatic levitation facility, optimized for in situ high-energy x-ray scattering studies of equilibrium and supercooled liquids
Abstract:
High-energy x-ray diffraction studies of metallic liquids provide valuable information about structural evolution on the atomic length scale, leading to insights into the origin of the nucleation barrier and the processes of supercooling and glass formation. The containerless processing of the beamline electrostatic levitation (BESL) facility allows coordinated thermophysical and structural studies of equilibrium and supercooled liquids to be made in a contamination-free, high-vacuum (∼10-8 Torr) environment. To date, the incorporation of electrostatic levitation facilities into synchrotron beamlines has been difficult due to the large footprint of the apparatus and the difficulties associated with its transportation and implementation. Here, we describe a modular levitation facility that is optimized for diffraction studies of high-temperature liquids at high-energy synchrotron beamlines. The modular approach used in the apparatus design allows it to be easily transported and quickly setup. Unlike most previous electrostatic levitation facilities, BESL can be operated by a single user instead of a user team.
Autors: Mauro, N. A.;Kelton, K. F.;
Appeared in: Review of Scientific Instruments
Publication date: Mar 2011, volume: 82, issue:3, pages: 035114 - 035114-6
Publisher: IEEE
 
» A Human Body Model for Efficient Numerical Characterization of UWB Signal Propagation in Wireless Body Area Networks
Abstract:
Wireless body area network (WBAN) is a new enabling system with promising applications in areas such as remote health monitoring and interpersonal communication. Reliable and optimum design of a WBAN system relies on a good understanding and in-depth studies of the wave propagation around a human body. However, the human body is a very complex structure and is computationally demanding to model. This paper aims to investigate the effects of the numerical model's structure complexity and feature details on the simulation results. Depending on the application, a simplified numerical model that meets desired simulation accuracy can be employed for efficient simulations. Measurements of ultra wideband (UWB) signal propagation along a human arm are performed and compared to the simulation results obtained with numerical arm models of different complexity levels. The influence of the arm shape and size, as well as tissue composition and complexity is investigated.
Autors: Lim, H. B.;Baumann, D.;Li, E.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Mar 2011, volume: 58, issue:3, pages: 689 - 697
Publisher: IEEE
 
» A Hybrid Approach to Detect and Localize Texts in Natural Scene Images
Abstract:
Text detection and localization in natural scene images is important for content-based image analysis. This problem is challenging due to the complex background, the non-uniform illumination, the variations of text font, size and line orientation. In this paper, we present a hybrid approach to robustly detect and localize texts in natural scene images. A text region detector is designed to estimate the text existing confidence and scale information in image pyramid, which help segment candidate text components by local binarization. To efficiently filter out the non-text components, a conditional random field (CRF) model considering unary component properties and binary contextual component relationships with supervised parameter learning is proposed. Finally, text components are grouped into text lines/words with a learning-based energy minimization method. Since all the three stages are learning-based, there are very few parameters requiring manual tuning. Experimental results evaluated on the ICDAR 2005 competition dataset show that our approach yields higher precision and recall performance compared with state-of-the-art methods. We also evaluated our approach on a multilingual image dataset with promising results.
Autors: Pan, Y.-F.;Hou, X.;Liu, C.-L.;
Appeared in: IEEE Transactions on Image Processing
Publication date: Mar 2011, volume: 20, issue:3, pages: 800 - 813
Publisher: IEEE
 
» A Hybrid Clustering Method for ROI Delineation in Small-Animal Dynamic PET Images: Application to the Automatic Estimation of FDG Input Functions
Abstract:
Tracer kinetic modeling with dynamic positron emission tomography (PET) requires a plasma time-activity curve (PTAC) as an input function. Several image-derived input function (IDIF) methods that rely on drawing the region of interest (ROI) in large vascular structures have been proposed to overcome the problems caused by the invasive approach for obtaining the PTAC, especially for small-animal studies. However, the manual placement of ROIs for estimating IDIF is subjective and labor-intensive, making it an undesirable and unreliable process. In this paper, we propose a novel hybrid clustering method (HCM) that objectively delineates ROIs in dynamic PET images for the estimation of IDIFs, and demonstrate its application to the mouse PET studies acquired with [ F]Fluoro-2-deoxy-2-D-glucose (FDG). We begin our HCM using k-means clustering for background removal. We then model the time-activity curves using polynomial regression mixture models in curve clustering for heart structure detection. The hierarchical clustering is finally applied for ROI refinements. The HCM achieved accurate ROI delineation in both computer simulations and experimental mouse studies. In the mouse studies, the predicted IDIF had a high correlation with the gold standard, the PTAC derived from the invasive blood samples. The results indicate that the proposed HCM has a great potential in ROI delineation for automatic estimation of IDIF in dynamic FDG-PET studies.
Autors: Zheng, X.;Tian, G.;Huang, S.-C.;Feng, D.;
Appeared in: IEEE Transactions on Information Technology in Biomedicine
Publication date: Mar 2011, volume: 15, issue:2, pages: 195 - 205
Publisher: IEEE
 
» A Kleene Algebra of Tagged System Actors
Abstract:
The tagged signal model (TSM) is a formal framework for modeling heterogeneous embedded systems. In the present work, we provide a representation of tagged systems using the semantics of Kleene algebra. Such an algebraic representation facilitates the usage of standard off-the-shelf theorem provers for reasoning about such systems for both behavioral verification through equivalence checking and property verification.
Autors: Dey, S.;Sarkar, D.;Basu, A.;
Appeared in: IEEE Embedded Systems Letters
Publication date: Mar 2011, volume: 3, issue:1, pages: 28 - 31
Publisher: IEEE
 
» A Laminated Waveguide Magic-T With Bandpass Filter Response in Multilayer LTCC
Abstract:
A laminated waveguide magic-T with imbedded Chebyshev filter response is developed in a multilayer low-temperature co-fired ceramic technology by vertically stacked rectangular cavity resonators with highly symmetric coupling structures. The cavities provide even- and odd-symmetric field distributions by simultaneously resonating and modes at the center frequency of the magic-T. Thus, the in-phase and out-of-phase responses of the magic-T function are accomplished according to the induced mode. Meanwhile, the filter frequency response is realized by the cascaded cavities with proper coupling strengths according to the filter specification. With the degenerate, but orthogonal cavity modes, a fewer number of cavities are required and the circuit size is further reduced. A third-order bandpass magic-T is designed and fabricated to operate at 24 GHz with 6% fractional bandwidth. The highly symmetric structure of the implemented magic-T provides a low in-band magnitude imbalance ( dB) and phase imbalance (0 –6 ). The sum and difference ports also provide an isolation greater than 30 dB in the operation frequency range. Measurement and simulated results are in good agreement, both validating the design concept.
Autors: Shen, T.-M.;Huang, T.-Y.;Chen, C.-F.;Wu, R.-B.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Mar 2011, volume: 59, issue:3, pages: 584 - 592
Publisher: IEEE
 
» A Large-Deviation Analysis of the Maximum-Likelihood Learning of Markov Tree Structures
Abstract:
The problem of maximum-likelihood (ML) estimation of discrete tree-structured distributions is considered. Chow and Liu established that ML-estimation reduces to the construction of a maximum-weight spanning tree using the empirical mutual information quantities as the edge weights. Using the theory of large-deviations, we analyze the exponent associated with the error probability of the event that the ML-estimate of the Markov tree structure differs from the true tree structure, given a set of independently drawn samples. By exploiting the fact that the output of ML-estimation is a tree, we establish that the error exponent is equal to the exponential rate of decay of a single dominant crossover event. We prove that in this dominant crossover event, a non-neighbor node pair replaces a true edge of the distribution that is along the path of edges in the true tree graph connecting the nodes in the non-neighbor pair. Using ideas from Euclidean information theory, we then analyze the scenario of ML-estimation in the very noisy learning regime and show that the error exponent can be approximated as a ratio, which is interpreted as the signal-to-noise ratio (SNR) for learning tree distributions. We show via numerical experiments that in this regime, our SNR approximation is accurate.
Autors: Tan, V. Y. F.;Anandkumar, A.;Tong, L.;Willsky, A. S.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Mar 2011, volume: 57, issue:3, pages: 1714 - 1735
Publisher: IEEE
 
» A Locally Amplified Strain Sensor Based on a Piezoelectric Polymer and Organic Field-Effect Transistors
Abstract:
Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation, which have complicated the development of array-based polyvinylidene difluoride (PVDF) sensors. We have used organic field-effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer, i.e., PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal, which can be detected even in the presence of parasitic capacitance. The device couples the voltage generated by the PVDF film under strain into the gate of organic thin-film transistors using an arrangement that allows the full piezoelectric voltage to couple to the channel while also increasing charge-retention time. A bipolar detector is created using ultraviolet–ozone treatment to shift the threshold voltage and increase the current of the transistor under both compressive and tensile strain. An array of devices that maps the strain field on a PVDF film surface is demonstrated.
Autors: Hsu, Y.-J.;Jia, Z.;Kymissis, I.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Mar 2011, volume: 58, issue:3, pages: 910 - 917
Publisher: IEEE
 
» A Low Complexity Decoder for Quasi-Orthogonal Space Time Block Codes
Abstract:
In this paper, a low-complexity suboptimal decoder for coherent and non-coherent quasi-orthogo-nal space time block codes with three and four transmit antennas is proposed. Our decoder enjoys a nearly linear complexity and approximately the same performance as the optimal maximum-likelihood (ML) decoder. Simulations show the advantages of the proposed decoder with respect to several other popular approaches to the coherent and non-coherent decoding.
Autors: Alabed, Samer J.;Paredes, Javier M.;Gershman, Alex B.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Mar 2011, volume: 10, issue:3, pages: 988 - 994
Publisher: IEEE
 
» A low complexity two dimensional differential demodulation for OFDM systems
Abstract:
 Abstract: A novel two dimensional differential demodulation (2D DD) is investigated, which exploits both the time and the frequency dimensions using the orthogonal frequency division multiplexing (OFDM) frame structure. Without changing the transmitter, the proposed 2D DD based on graph attempts to search for a more confident bypass, probably containing multiple DD operations. Simplified soft decision metrics of the amplitude ratio and phase difference are derived by making use of a Gaussian approximation. Two optimal path searching algorithms, based on depth-first search (DFS) and breadth-first search (BFS) respectively, are brought up and analyzed in details. Moreover, a random access memory (RAM)...
Autors: Min, Gong , Han, Han , Chao, Zhang , Xiaokang, Lin
Appeared in: AEU - International Journal of Electronics and Communications
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A low gate leakage current and small equivalent oxide thickness MOSFET with Ti/HfO2 high-k gate dielectric
Abstract:
Annealing effects on electrical characteristics and reliability of MOS device with HfO2 or Ti/HfO2 high-k dielectric are studied in this work. For the sample with Ti/HfO2 higher-k dielectric after a post-metallization annealing (PMA) at 600 °C, its equivalent oxide thickness value is 7.6 Ċ and the leakage density is about 4.5x 10-2A/cm2. As the PMA is above 700 °C, the electrical characteristics of MOS device would be severely degraded.
Autors: C.H., Fu , K.S., Chang-Liao , Y.A., Chang , Y.Y., Hsu , T.H., Tzeng , ...
Appeared in: Microelectronic Engineering
Publication date: Mar 2011
Publisher: Elsevier B.V.
 
» A Low-Cost and Low-Power Time-to-Digital Converter Using Triple-Slope Time Stretching
Abstract:
In this brief, we present a time-to-digital converter (TDC) in which a single interpolator is used to improve the resolution by time stretching. The interpolator is based on a triple-slope conversion. Without slowing down the measured event, this approach extensively reduces the chip area and the corresponding power consumption, as compared with the prior arts with two parallel time interpolators. A prototype was designed and fabricated in a 0.35- CMOS digital process, and its core area merely occupies 0.126 . Measurements show that our TDC achieves a resolution of 357 ps while consuming 1.22 mW with a 2.5-V supply. The dynamic range of the TDC exceeds 1.46 . The measurement rate can achieve above 400 kS/s.
Autors: Kim, M.;Lee, H.;Woo, J.-K.;Xing, N.;Kim, M.-O.;Kim, S.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Mar 2011, volume: 58, issue:3, pages: 169 - 173
Publisher: IEEE
 
» A Low-Cost Disposable Chemical Sensing Platform Based on Discrete Components
Abstract:
A method of fabricating low-cost chemical sensing platforms is presented. The device utilizes a discrete metal–oxide–semiconductor field-effect transistor to detect ionic concentrations in electrolytes, with particular emphasis to pH. Measured results indicate a chemical sensitivity of 36.5 mV/pH, while the device exhibits low-leakage currents (in picoamperes) and a drift of 9 mV/h. The proposed technique has a great potential for disposable implementations, while the sensing selectivity of the device can be easily altered, resulting into a versatile platform.
Autors: Prodromakis, T.;Liu, Y.;Toumazou, C.;
Appeared in: IEEE Electron Device Letters
Publication date: Mar 2011, volume: 32, issue:3, pages: 417 - 419
Publisher: IEEE
 
» A Low-Cost Method for Measuring Surface Currents and Modeling Drifting Objects
Abstract:
The ability to measure and model water currents is essential to ensure the safety and correct operations of many water surface activities. For example, the complex currents in harbors seriously affect the safety of vessels, while river turbulence and vortices cause safety hazards for people participating in white-water rafting, swimming, and other sports activities. In this paper, we demonstrate a low-cost method to measure and model surface currents. Specially designed GPS sensors are dropped into the water to record their drifting trajectories, which are then transformed into a current map to show the characteristics of the currents, including their velocity and direction. A proof-of-concept experiment shows the feasibility of the proposed method and how turbulence locations can be identified. We further demonstrate that the derived current map can be used to construct a mobility model of a drifting object and generate its virtual drifting trajectories. Our analyses show that the generated virtual trajectories closely fit the collected trajectories.
Autors: Huang-Chen Lee;Chun-Yu Lin;Chun-Han Lin;Sheng-Wen Hsu;Chung-Ta King;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Mar 2011, volume: 60, issue:3, pages: 980 - 989
Publisher: IEEE
 
» A Low-IF/Zero-IF Reconfigurable Analog Baseband IC With an I/Q Imbalance Cancellation Scheme
Abstract:
A low-IF/zero-IF reconfigurable analog baseband IC embodying an automatic I/Q imbalance cancellation scheme is reported. The chip, which comprises a down-conversion mixer, an analog baseband filter, and a programmable gain amplifier, achieves a high image rejection of 55 dB without any calibration. It operates over a wide radio frequency range of 0.4–2.4 GHz, and has a cut-off frequency range of 0.3–30 MHz in zero-intermediate frequency (IF) mode and an IF range of 0.2–6 MHz in low-IF mode. The circuit in the receiver chain draws only 4.5–6.2 mA, and the clock generator including LO buffers draws 1.8–6.3 mA from a 1.2-V supply. The chip, implemented in 90-nm CMOS technology, occupies an area of 1.1 .
Autors: Kitsunezuka, M.;Tokairin, T.;Maeda, T.;Fukaishi, M.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Mar 2011, volume: 46, issue:3, pages: 572 - 582
Publisher: IEEE
 
» A Low-Overhead Partition-Oriented ERfair Scheduler for Hard Real-Time Embedded Systems
Abstract:
This letter presents partition-oriented ERfair scheduler (POES), a low-overhead proportional fair scheduler for hard real-time multiprocessor embedded systems. POES achieves lower overheads using an online partitioning/merging mechanism that retains the optimal schedulability of a fully global scheduler by merging processor groups as resources become critical while using partitioning for fast scheduling at other times. The principal objective is to remain only just as global at any given instant of time as is necessary to maintain ERfair schedulability of the system throughout the schedule length. Experimental results reveal that POES incurs almost no migrations at low workloads and achieves up to 32 times reduction in the number of migrations suffered with respect to the global ERfair scheduler on a set of two to 16 processors even when the average system load is as high as 85%. Theoretical analysis proves that POES typically has the same amortized complexity as that of the global ERfair algorithm.
Autors: Sarkar, A.;Shanker, A.;Ghose, S.;Chakrabarti, P. P.;
Appeared in: IEEE Embedded Systems Letters
Publication date: Mar 2011, volume: 3, issue:1, pages: 5 - 8
Publisher: IEEE
 

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