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Electrical and Electronics Engineering publications abstract of: 02-2011 sorted by title, page: 0
» 0.5 keV Xe+ ion beam nano smoothing of ULE® substrate after processing with 3.0-10.0 keV Xe+ ion beam
Abstract:
Ion beam figuring (IBF) is a suitable technology for the final shape correction of substrates used in the projection optics of EUVL tools. Generally the ULE® substrate with surface roughness of 0.060~0.080 nm rms can be produced with mechanical machining methods. However, it is very difficult to obtain the shape accuracy of approximately 0.120 nm rms using mechanical machining methods. Therefore, ion beam figuring (IBF) may be adapted for the final shape correction of the substrates. In this paper, we investigated a method in which a low energy 0.5 keV Xe+ ion beam is used for smoothing of ULE® substrates...
Autors: K., Morijiri , H., Endo , K., Morikaawa , S.A., Pahlovy , I., Miyamoto
Appeared in: Microelectronic Engineering
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» 1/f noise in advanced CMOS transistors
Abstract:
Complementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over the past two decades [1]. The continuous downscaling of CMOS technologies towards nano feature size has increased the performance of integrated circuits considerably. However, one important limitation of MOSFET downscaling is an increase of 1/f noise (often referred to as low-frequency noise), since the 1/f noise increases as the reciprocal of the device area [2], [3]. Furthermore, the development of nano-sized CMOS technologies has led to the observation of random telegraph signals (RTS) [4] yielding large low frequency current fluctuations. Excessive low-frequency noise introduces serious limitations on the functionality of analog and digital circuits since it deteriorates the noise figure of operational amplifiers and A/D and D/A converters. Lowfrequency noise diminishes the signal-to-noise-ratio (SNR) of CMOS sensors, such as IR or CMOS image sensors [5] [6]. The 1/f noise is also of paramount importance in RF circuit applications where it gives rise to phase noise in oscillators or multiplexers [7]. The 1/f noise is a sensitive diagnostic tool to monitor radiation effects on MOSFETs [8].
Autors: Nemirovsky, Y.;Corcos, D.;Brouk, I.;Nemirovsky, A.;Chaudhry, S.;
Appeared in: IEEE Instrumentation & Measurement Magazine
Publication date: Feb 2011, volume: 14, issue:1, pages: 14 - 22
Publisher: IEEE
 
» 10 Channel, 45.6 Gb/s per Channel, Polarization-Multiplexed DQPSK, InP Receiver Photonic Integrated Circuit
Abstract:
We demonstrate a 10 wavelength, 200 GHz spaced, monolithically integrated, polarization-multiplexed, InP differential quadrature phase shift keying receiver operating at 45.6 Gb/s per wavelength. The receiver is based on a novel technique for polarization demodulation and phase tracking that does not require any external components.
Autors: Nagarajan, R.;Rahn, J.;Kato, M.;Pleumeekers, J.;Lambert, D.;Lal, V.;Tsai, H.-S.;Nilsson, A.;Dentai, A.;Kuntz, M.;Malendevich, R.;Tang, J.;Zhang, J.;Butrie, T.;Raburn, M.;Little, B.;Chen, W.;Goldfarb, G.;Dominic, V.;Taylor, B.;Reffle, M.;Kish, F.;Welc
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2011, volume: 29, issue:4, pages: 386 - 395
Publisher: IEEE
 
» 170-862MHz, 6.16mW compact switched-gain low-noise amplifier
Abstract:
This paper presents a switched-gain low-noise amplifier (SGLNA). The proposed SGLNA achieves three-step variable gains by combining the current-steering and inter-stage impedance-mismatching techniques. The proposed amplifier was designed using a TSMC 0.18?m mixed-signal CMOS process. Post-layout simulation results demonstrate that the SGLNA achieves a gain range of -24.9 to +21.8dB and a noise figure range of 3.56-4.13dB over the frequency range of 170-862MHz. The S11 and S22 are both <-15dB over the same frequency range. The SGLNA occupies an active area of 0.053mm2 and consumes 6.16mW in high-gain mode from a 1.8V power supply.
Autors: Chun-Chieh, Chen , Ping-Huan, Tsai , Yen-Chun, Wang
Appeared in: AEU - International Journal of Electronics and Communications
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» 2-D Exact Analytical Model for Surface-Mounted Permanent-Magnet Motors With Semi-Closed Slots
Abstract:
This paper presents an analytical subdomain model to compute the magnetic field distribution in surface-mounted permanent-magnet (PM) motors with semi-closed slots. The proposed model is sufficiently general to be used with any pole and slot combinations including fractional slot machines with distributed or concentrated windings. The model accurately accounts for armature reaction magnetic field and mutual influence between the slots. The analytical method is based on the resolution of two-dimensional Laplace's and Poisson's equations in polar coordinates (by the separation of variables technique) for each subdomain, i.e., magnet, air gap, slot-opening, and slots. Magnetic field distributions, back-EMF, and electromagnetic torque (including cogging torque) computed with the proposed analytical method are compared with those issued from finite-element analyses.
Autors: Lubin, T.;Mezani, S.;Rezzoug, A.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Feb 2011, volume: 47, issue:2, pages: 479 - 492
Publisher: IEEE
 
» 2010 IEEE World Congress on Computational Intelligence (2010 IEEE WCCI) [Conference Report]
Abstract:
Autors: Sobrevilla, P.;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Feb 2011, volume: 6, issue:1, pages: 17 - 19
Publisher: IEEE
 
» 2010 Reviewer appreciation
Abstract:
[No author name available]
Autors: Source: Advanced Powder Technology, Volume 22, Issue 1, January 2011, Pages 150-152
Appeared in: Advanced Powder Technology
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» 2010 Reviewers List
Abstract:
Autors: Muller, R.;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Feb 2011, volume: 20, issue:1, pages: 3 - 5
Publisher: IEEE
 
» 2011 IEEE CIS Awards [Society Briefs]
Abstract:
Autors: Polycarpou, M.M.;
Appeared in: IEEE Computational Intelligence Magazine
Publication date: Feb 2011, volume: 6, issue:1, pages: 5 - 10
Publisher: IEEE
 
» 2011 IT Tech and Strategy Trends
Abstract:
It's the time of year for "top 10" lists. Most such lists are very technology or tool centric and can be more visionary than practical. Few address the softer skills and issues that today's CIOs face. This department offers two top 10 lists for 2011&#x2014;one on tech trends and the other on strategic capabilities. They include trends that span beyond IT and improve both the execution and integration of IT across the entire enterprise constituent pool.
Autors: Costello, Tom;
Appeared in: IT Professional
Publication date: Feb 2011, volume: 13, issue:1, pages: 61 - 65
Publisher: IEEE
 
» 3-d numerical simulation of particle concentration effect on a single-wire ESP performance for collecting poly-dispersed particles
Abstract:
In this paper a simple one stage wire-plate electrostatic precipitator is analyzed to predict particle transport and charging, and airflow patterns under the influence of EHD and external flows, assuming various particle concentrations. The investigated numerical model includes the governing equations describing the motion of ions, gas, solid particles and the effect of particle space charge. The complicated mutual interaction mechanisms between the three coexisting fields of gas flow, particle trajectories and electrostatic field, which affect an industrial ESP process, have been implemented using the User Defined Functions (UDFs) in commercial FLUENT 6.2 software. The electrostatic field and ionic space charge density due to corona discharge were computed by numerical solution of Poisson and current continuity equations using a hybrid Finite Element - Flux Corrected Transport method. The model takes into account the particle space charge density effect on the ionic charge density distribution. The airflow equations were solved inside FLUENT using the Finite Volume Method and the turbulence effect was included by using the k-ε model. The Lagrangian random walk approach was used to determine particle motion, as affected by EHD flows and turbulence effects. This part was performed with the aid of Discrete Phase Model (DPM) in FLUENT. The performance of the discussed ESP in the removal of particulates and the effect of different particle concentration on the gas flow pattern and corona discharge current was evaluated numerically assuming poly-dispersed particles with lognormal particle size distribution.
Autors: Farnoosh, N.;Adamiak, K.;Castle, G.S.P.;
Appeared in: IEEE Transactions on Dielectrics and Electrical Insulation
Publication date: Feb 2011, volume: 18, issue:1, pages: 211 - 220
Publisher: IEEE
 
» 32 GS/s ultra-high-speed UWB sampling circuit for portable imaging system
Abstract:
A 32GS/s ultra-high-speed ultra-wideband (UWB) sampling circuit has been developed by use of a 65 nm CMOS technology. An equivalent time sampling technique was applied using an internal clock generator to achieve its low power consumption and high sampling rate. The generator consists of an eight-stage 2 GHz phase-locked loop, a 16-to-1 multiplexer and a frequency divider. Both a 20 mW low power consumption and a 32 GS/s high sampling rate were achieved. Gaussian monocycle pulse signals with a centre frequency of 450 MHz could be successfully converted to digital codes.
Autors: Toya, A.;Sasaki, N.;Kubota, S.;Kikkawa, T.;
Appeared in: Electronics Letters
Publication date: Feb 2011, volume: 47, issue:3, pages: 165 - 167
Publisher: IEEE
 
» 36th European Conference on Optical Communication [ECOC 2010 Conference Report]
Abstract:
Autors: Neri, F.;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2011, volume: 49, issue:2, pages: s8 - s10
Publisher: IEEE
 
» 3D registration of point clouds from time-of-flight cameras
Abstract:
A novel approach for aligning two 3D point clouds acquired by time-of-flight (TOF) cameras is presented. Given that the density of 3D data of these devices is not high, the alignment will be carried out using descriptors based on a direct encoding of the environment of a set of previously selected points-of-interest. This will allow the design of a similarity measure that behaves correctly when both the density of the point clouds and the overlap between them are low. Furthermore, this combination of descriptor and similarity measure facilitates the alignment of point clouds from devices with different accuracy and resolution (such as a laser scanner and a TOF camera).
Autors: Torre-Ferrero, C.;Llata, J.R.;Robla, S.;Sarabia, E.G.;
Appeared in: Electronics Letters
Publication date: Feb 2011, volume: 47, issue:3, pages: 175 - 177
Publisher: IEEE
 
» 3D-Monte Carlo study of short channel tri-gate nanowire MOSFETs
Abstract:
 Research highlights: ? 3D Semiclassical Monte Carlo simulation of III-V and Si tri-gate nanowire FETs. ? Schrodinger correction with Poisson solver and non-parabolic band approximation. ? Carrier velocity as opposed to quantum/dos capacitances vary Ids between materials. ? InAs and InSb show superior performance.

Autors: As a result of recent trends in processor speed and core temperature, III-V semiconductors have become a tempting replacement for Si in semiconductor logic. However, as device geometries shrink, the advantages of such a switch are put into question.
Appeared in: Solid-State Electronics
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» 448-Gb/s Reduced-Guard-Interval CO-OFDM Transmission Over 2000 km of Ultra-Large-Area Fiber and Five 80-GHz-Grid ROADMs
Abstract:
We propose a novel coherent optical orthogonal frequency-division multiplexing (CO-OFDM) scheme with reduced guard interval (RGI) for high-speed high-spectral-efficiency long-haul optical transmission. In this scheme, fiber chromatic dispersion is compensated for within the receiver rather than being accommodated by the guard interval (GI) as in conventional CO-OFDM, thereby reducing the needed GI, especially when fiber dispersion is large. We demonstrate the generation of a 448-Gb/s RGI-CO-OFDM signal with 16-QAM subcarrier modulation through orthogonal band multiplexing. This signal occupies an optical bandwidth of 60 GHz, and is transmitted over 2000 km of ultra-large-area fiber (ULAF) with five passes through an 80-GHz-grid wavelength-selective switch. Banded digital coherent detection with two detection bands is used to receive this 448-Gb/s signal. Wavelength-division multiplexed transmission of three 80-GHz spaced 448-Gb/s RGI-CO-OFDM channels is also demonstrated, achieving a net system spectral efficiency of 5.2 b/s/Hz and a transmission distance of 1600 km of ULAF.
Autors: Liu, X.;Chandrasekhar, S.;Zhu, B.;Winzer, P. J.;Gnauck, A. H.;Peckham, D. W.;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2011, volume: 29, issue:4, pages: 483 - 490
Publisher: IEEE
 
» 6-DOF tracker using LED directivity
Abstract:
Proposed is a new concept for a 6-DOF optical tracker exploiting the directivity of an LED. To verify the concept, a low-noise, linear optical sensor was designed, a working prototype was built that solves a source-localisation problem in real time, and its performance, compared with a reference tracker, was evaluated.
Autors: Han, J.;Heo, S.;Lee, G.;Bang, W.-C.;Kim, D.K.;Kim, C.Y.;
Appeared in: Electronics Letters
Publication date: Feb 2011, volume: 47, issue:3, pages: 177 - 178
Publisher: IEEE
 
» 8 448-Gb/s WDM Transmission of 56-GBd PDM 16-QAM OTDM Signals Over 250-km Ultralarge Effective Area Fiber
Abstract:
An 8 448-Gb/s polarization-division-multiplexing 16-ary quadrature amplitude modulation wavelength-division multiplexing signal with 4-b/s/Hz spectral efficiency is generated using optical time-division multiplexing and real-time field-programmable gate array-based generation of four-level in-phase and quadrature modulator driving signals. Transmission performance over 250-km ultralarge effective area fiber with erbium-doped fiber amplifier-only amplification is investigated.Pub _bookmark Command="[Quick Mark]"
Autors: Fischer, J. K.;Molle, L.;Nolle, M.;Schmidt-Langhorst, C.;Hilt, J.;Ludwig, R.;Peckham, D. W.;Schubert, C.;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2011, volume: 23, issue:4, pages: 239 - 241
Publisher: IEEE
 
» 8 448-Gb/s WDM Transmission of 56-GBd PDM 16-QAM OTDM Signals Over 250-km Ultralarge Effective Area Fiber
Abstract:
An 8 448-Gb/s polarization-division-multiplexing 16-ary quadrature amplitude modulation wavelength-division multiplexing signal with 4-b/s/Hz spectral efficiency is generated using optical time-division multiplexing and real-time field-programmable gate array-based generation of four-level in-phase and quadrature modulator driving signals. Transmission performance over 250-km ultralarge effective area fiber with erbium-doped fiber amplifier-only amplification is investigated.Pub _bookmark Command="[Quick Mark]"
Autors: Fischer, J. K.;Molle, L.;Nolle, M.;Schmidt-Langhorst, C.;Hilt, J.;Ludwig, R.;Peckham, D. W.;Schubert, C.;
Appeared in: IEEE Photonics Technology Letters
Publication date: Feb 2011, volume: 23, issue:4, pages: 239 - 241
Publisher: IEEE
 
» Etching With Aqueous HF: Design and Development of a Laboratory-Scale Integrated Wet Etch/Dry Reactor
Abstract:
Etching of films using aqueous HF-based chemistries is widely used in integrated circuit and microelectromechanical device industries. To precisely control film loss during cleaning or etching processes, good control over the contact time between the wet chemistry and the substrate is necessary. An integrated wet etch and dry reactor system has been designed and fabricated by studying various geometrical configurations using computational fluid dynamics simulations incorporating reaction kinetics from laboratory data and previously published information. The effect of various process parameters such as HF concentration, flow rate, and flow velocity on the etch rates and uniformity of thermally-grown silicon dioxide and borophosphosilicate glass films was studied. Simulations agree with experiments within experimental error. This reactor can also be used to wet etch/clean and dry other films in addition to based films using aggressive chemistries in addition to aqueous HF under widely different process conditions.
Autors: Pande, A. A.;Mui, D. S. L.;Hess, D. W.;
Appeared in: IEEE Transactions on Semiconductor Manufacturing
Publication date: Feb 2011, volume: 24, issue:1, pages: 104 - 116
Publisher: IEEE
 
» Mode Effect on Direct Wave in Single-Hole Borehole Radar
Abstract:
In this paper, we investigate the influence of radar sonde eccentricity on a direct wave between a transmitting and a receiving antenna in a single-hole borehole radar measurement. We analyze the direct wave using an analytical method with the approximated solution of branch cut integrals and that of residues of poles. According to our calculation, at high frequencies above 200 MHz, guided waves, which are caused by the poles, play a vital role in the direct wave. We found that the most important pole is the mode one, which is excited only when the antenna is eccentered in the borehole. We show that this causes artificial noise in the moving average subtraction, which is a common signal processing method used to remove the direct wave. In a laboratory experiment with a ground plane, we confirmed the excitation of the guided waves when the antenna was eccentered. In field experiments in granite, we conducted a special experiment, in which the location and rotation of the radar sonde were controlled mechanically. We found the excitation of the mode at high frequencies when the sonde was noncentered by 1.7 cm in a borehole. These effects are also predicted in a theoretical analysis.
Autors: Ebihara, S.;Sasakura, A.;Takemoto, T.;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Feb 2011, volume: 49, issue:2, pages: 854 - 867
Publisher: IEEE
 
» Characteristics in Undoped Gate-All-Around Nanowire FET Array
Abstract:
Presented in this letter are the data, measured from nanowire capacitors, which have been fabricated by connecting in parallel a large number of identically processed nanowire FETs. The curves were examined over a range from accumulation to inversion with varying frequencies and at different electrode configurations. The gate response of the undoped and floating channel is investigated using data, and the inversion charge and carrier mobility are accurately extracted by eliminating the effects of parasitic capacitances and series resistance . These observed data are compared with the data from planar MOS capacitor.
Autors: Baek, R.-H.;Baek, C.-K.;Lee, S.-H.;Suk, S. D.;Li, M.;Yeoh, Y. Y.;Yeo, K. H.;Kim, D.-W.;Lee, J.-S.;Kim, D. M.;Jeong, Y.-H.;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2011, volume: 32, issue:2, pages: 116 - 118
Publisher: IEEE
 
» Characteristics in Undoped Gate-All-Around Nanowire FET Array
Abstract:
Presented in this letter are the data, measured from nanowire capacitors, which have been fabricated by connecting in parallel a large number of identically processed nanowire FETs. The curves were examined over a range from accumulation to inversion with varying frequencies and at different electrode configurations. The gate response of the undoped and floating channel is investigated using data, and the inversion charge and carrier mobility are accurately extracted by eliminating the effects of parasitic capacitances and series resistance . These observed data are compared with the data from planar MOS capacitor.
Autors: Baek, R.-H.;Baek, C.-K.;Lee, S.-H.;Suk, S. D.;Li, M.;Yeoh, Y. Y.;Yeo, K. H.;Kim, D.-W.;Lee, J.-S.;Kim, D. M.;Jeong, Y.-H.;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2011, volume: 32, issue:2, pages: 116 - 118
Publisher: IEEE
 
» -Gate MOS-HEMTs by Methods of Ozone Water Oxidation and Shifted Exposure
Abstract:
This letter reports, for the first time, a -gate metal–oxide–semiconductor high-electron-mobility transistor (MOS-HEMT), which can achieve gate-length reduction, improved gate insulation, and formations of a field plate and a full surface passivation within the drain–source region at the same time by using the ozone water oxidation and shifted exposure techniques. The present -gate MOS-HEMT has demonstrated significant improvements of 523% in the two-terminal gate–drain breakdown, 137% in the on -state drain–source breakdown, and 28%/39.3% in the unity-gain cutoff frequency/maximum oscillation frequency , as compared to a conventional Schottky-gate device fabricated upon the same epitaxial structure by using an identical optical mask.
Autors: Lee, C.-S.;Yang, S.-H.;Lin, M.-Y.;
Appeared in: IEEE Electron Device Letters
Publication date: Feb 2011, volume: 32, issue:2, pages: 152 - 154
Publisher: IEEE
 
» A 0.5-MJ 18-kV Module of Capacitive Energy Storage
Abstract:
A module of the capacitive energy storage is designed for experiments with high-current electrical discharges in dense media. The module is remotely controlled and consists essentially of eight capacitor cells with semiconductor switches built around reverse-switching dynistors (RSDs). It includes a charger with a high-frequency inverter, a protective contactor with normally closed high-voltage contacts, cell RSD switch controls, and control and diagnostic equipment provided with a programmable logic controller. The semiconductor switches in the capacitor cells are triggered by light pulses transmitted from a remote-control panel over eight fiber-optic cables. Information exchange between the module control and diagnostic system and the remote terminal is realized likewise over two fiber-optic cables. The storage is designed to operate in a programmable discharge mode in which the semiconductor switches in the capacitor cells are activated by a preset time-sequence program. The maximum current pulse amplitude of 400 kA at the module output is reached under synchronous discharge of all eight cells in the short-circuit mode. In these conditions, the pulse rise time is 150 . The volume of the capacitor module is 1.3 .
Autors: Fridman, B. E.;Enikeev, R. S.;Korotkov, S. V.;Kovrizhnykh, N. A.;Lobanov, K. M.;Serebrov, R. A.;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Feb 2011, volume: 39, issue:2, pages: 769 - 774
Publisher: IEEE
 
» A 0.5-V Biomedical System-on-a-Chip for Intrabody Communication System
Abstract:
A low-voltage (0.5 V) and low-power (4.535 mW) monolithic biomedical system-on-a-chip (SOC) consisting of a receiver, a transmitter, a microcontrol unit, and an analog-to-digital converter (ADC), implemented in a 0.18- CMOS technology for intrabody communication is first reported. The SOC can take command through a human body and activate (or turn on) the ADC and transmitter inside the SOC. Then, a biomedical signal is converted to digital format and transmitted to the RF gateway through a human body. With this transmission methodology and the proposed SOC circuit, it is much more power efficient than wireless communication. Moreover, since no antenna is required, the chip size of the SOC is only 1.5 , excluding the test pads.
Autors: Lin, Y.-T.;Lin, Y.-S.;Chen, C.-H.;Chen, H.-C.;Yang, Y.-C.;Lu, S.-S.;
Appeared in: IEEE Transactions on Industrial Electronics
Publication date: Feb 2011, volume: 58, issue:2, pages: 690 - 699
Publisher: IEEE
 
» A 1 GHz Equiripple Low-Pass Filter With a High-Speed Automatic Tuning Scheme
Abstract:
A continuous-time fourth-order equiripple linear phase filter with an automatic tuning circuit is presented. A high speed OTA based on the inverter structure is realized. The combined common-mode feedforward and common-mode feedback circuit ensures the input and output common-mode stability. The gain performance could be maintained by combining an equivalent negative resistor circuit at the output nodes. Transconductance tuning can be achieved by adjusting the bulk voltage by using the deep-NWELL technology. The modified automatic tuning circuit relaxes the speed requirement of the tuning blocks. Through the use of the operational transconductance amplifier as a building block with the automatic tuning scheme, the filter 3 dB cutoff frequency is 1 GHz with the group delay less than 4% variation up to 1.5 fc frequency. The 43 dB of IM3 at filter cutoff frequency is obtained with 4 dbm two-tone signals. Implemented in 0.18- m CMOS process, the chip occupies 1 mm and consumes 175 mW at a 1.5-V supply voltage.
Autors: Lo, T.-Y.;Hung, C.-C.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Feb 2011, volume: 19, issue:2, pages: 175 - 181
Publisher: IEEE
 
» A 1.0–4.0-Gb/s All-Digital CDR With 1.0-ps Period Resolution DCO and Adaptive Proportional Gain Control
Abstract:
This paper describes the design and implementation of an all-digital clock and data recovery circuit (ADCDR) for multigigabit/s operation. The proposed digitally-controlled oscillator (DCO) incorporating a supply-controlled ring oscillator with a digitally-controlled resistor (DCR) generates wide-frequency-range multiphase clocks with fine resolution. With an adaptive proportional gain controller (APGC) which continuously adjusts a proportional gain, the proposed ADCDR recovers data with a low-jitter clock and tracks large input jitter rapidly, resulting in enhanced jitter performance. A digital frequency-acquisition loop with a proportional control greatly reduces acquisition time. Fabricated in a 0.13- CMOS process with a 1.2-V supply, the ADCDR occupies 0.074 and operates from 1.0 Gb/s to 4.0 Gb/s with a bit error rate of less than . At a 3.0-Gb/s PRBS, the measured jitter in the recovered clock is 3.59 and 29.4 , and the power consumption is 11.4 mW.
Autors: Song, H.;Kim, D.-S.;Oh, D.-H.;Kim, S.;Jeong, D.-K.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 424 - 434
Publisher: IEEE
 
» A 110 MHz to 1.4 GHz Locking 40-Phase All-Digital DLL
Abstract:
An all-digital DLL is designed to generate low jittery 40 phases in a continuous lock range of 110 MHz to 1.4 GHz. The DLL is driven by dual loops—one for phase lock and the other for offset calibration. The two loops are updated by a chopping PD which adaptively extracts valid information for each loop, one at a time. For the optimal 1-bit delay resolution in the entire lock range, a piecewise profiling of delay line is also proposed. The DLL, fabricated in a 0.13 CMOS, reveals the best linearity performance compared with previously reported works, showing a DNL of less than 0.3 LSB and a INL of less than 0.8 LSB in the entire lock range up to 1.4 GHz. With the piecewise-fitted delay line, the amount of peak-to-peak and rms jitters induced by DLL operation is controlled to be less than 0.825% and 0.2% of the clock period, respectively. Power consumption was 74.4 mW at the supply voltage of 1.2 V.
Autors: Kim, Y.-S.;Lee, S.-K.;Park, H.-J.;Sim, J.-Y.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 435 - 444
Publisher: IEEE
 
» A 128 Mb Chain FeRAM and System Design for HDD Application and Enhanced HDD Performance
Abstract:
This paper demonstrates the hard disk drive (HDD) performance improvement by nonvolatile FeRAM cache. First, an array architecture and data path design of 128 Mb chain FeRAM to meet HDD specifications, and a total power supply system for HDD application are presented. A 1.6 GB/s read/write bandwidth with page length of 512 Byte HDD sector size, and the data protection against sudden power failure have been realized. Second, the concept of nonvolatile FeRAM cache to utilize cache memory to the maximum by ignoring flush cache commands issued from Windows OS is presented. Third, the simulated and measured HDD performance improvements are demonstrated. The read/write bandwidth improvements by 1.12 times, 3.3 times and 1.9 times have been verified by two benchmark tests of PC Mark 05 and the copy of FD Bench v1.01, and by simulation using the PC user data for five days, respectively. These results are at the same levels of, or more effective than, the results of HDD disk rotational speed-up from 5400 rpm to 7200 rpm using a DRAM cache. The write energy is also reduced by 25% in PC Mark05 test.
Autors: Takashima, D.;Nagadomi, Y.;Hatsuda, K.;Watanabe, Y.;Fujii, S.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 530 - 536
Publisher: IEEE
 
» A 130 mV SRAM With Expanded Write and Read Margins for Subthreshold Applications
Abstract:
SRAM suffers read-disturb and write failures at a low supply voltage, especially at deep subthreshold operation. This study proposes a 9T-SRAM cell with a data-aware-feedback-cutoff (DAFC) scheme to enlarge the write margin and dynamic-read-decoupled (DRD) scheme to prevent read-disturb for achieving deep subthreshold operation. A 30 mV negative-pumped wordline scheme is employed to suppress bitline leakage current. The fabricated 90 nm 32 Kb 9T-SRAM macro achieves 130 mV VDDmin. All the 32 Kb 9T cells are stable across read and write operations when operated at 105 mV.
Autors: Chang, M.-F.;Chang, S.-W.;Chou, P.-W.;Wu, W.-C.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 520 - 529
Publisher: IEEE
 
» A 135-km 8192-Split Carrier Distributed DWDM-TDMA PON With 2 32 10 Gb/s Capacity
Abstract:
We present a hybrid dense wavelength-division-multiplexed time-division multiple access passive optical network (DWDM-TDMA PON) with record performance in terms of reach (135.1 km of which 124 km were field-installed fibers), number of supported optical network units (ONUs—8192) and capacity (symmetric 320 Gb/s). This was done using 32-, 50-GHz-spaced downstream wavelengths and another 32-, 50-GHz-spaced upstream wavelengths, each carrying 10 Gb/s traffic (256 ONUs per wavelength, upstream operated in burst mode). The 10 Gb/s downstream channels were based upon DFB lasers (arranged in a DWDM grid), whose outputs were modulated using a electro-absorption modulator (EAM). The downstream channels were terminated using avalanche photodiodes in the optical networks units (ONUs). Erbium-doped fiber amplifiers (EDFAs) provided the gain to overcome the large fiber and splitting losses. The 10 Gb/s upstream channels were based upon seed carriers (arranged in a DWDM grid) distributed from the service node towards the optical network units (ONUs) located in the user's premises. The ONUs boosted, modulated, and reflected these seed carriers back toward the service node using integrated 10 Gb/s reflective EAM-SOAs (EAM-semiconductor optical amplifier). This seed carrier distribution scheme offers the advantage that all wavelength referencing is done in the well-controlled environment of the service node. The bursty upstream channels were further supported by gain stabilized EDFAs and a 3R 10 Gb/s burst-mode receiver with electronic dispersion compensation. The demonstrated network concept allows integration of metro and optical access networks into a single all-optical system, which has potential for capital and operational expenditure savings for operators.
Autors: Ossieur, P.;Antony, C.;Clarke, A. M.;Naughton, A.;Krimmel, H.-G.;Chang, Y.;Ford, C.;Borghesani, A.;Moodie, D.;Poustie, A.;Wyatt, R.;Harmon, B.;Lealman, I.;Maxwell, G.;Rogers, D.;Smith, D. W.;Nesset, D.;Davey, R. P.;Townsend, P. D.;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2011, volume: 29, issue:4, pages: 463 - 474
Publisher: IEEE
 
» A 2-D Passive-Dynamic-Running Biped With Elastic Elements
Abstract:
This is the first study of a real physical kneed bipedal robot that exhibits passive-dynamic running (PDR), i.e., a bipedal gait with a flight phase in a device without an actuator. By carefully designing the properties of the elastic elements implemented into the hip joints and the stance legs in this device, we achieved a stable PDR consisting of 36 steps. The main contribution of this paper is the demonstration of PDR in the real world, which fully exploits the elastic mechanical properties.
Autors: Owaki, D.;Koyama, M.;Yamaguchi, S.;Kubo, S.;Ishiguro, A.;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2011, volume: 27, issue:1, pages: 156 - 162
Publisher: IEEE
 
» A 2.4-GHz Energy-Efficient Transmitter for Wireless Medical Applications
Abstract:
A 2.4-GHz energy-efficient transmitter (TX) for wireless medical applications is presented in this paper. It consists of four blocks: a phase-locked loop (PLL) synthesizer with a direct frequency presetting technique, a class-B power amplifier, a digital processor, and nonvolatile memory (NVM). The frequency presetting technique can accurately preset the carrier frequency of the voltage-controlled oscillator and reduce the lock-in time of the PLL synthesizer, further increasing the data rate of communication with low power consumption. The digital processor automatically compensates preset frequency variation with process, voltage, and temperature. The NVM stores the presetting signals and calibration data so that the TX can avoid the repetitive calibration process and save the energy in practical applications. The design is implemented in 0.18- m radio-frequency complementary metal–oxide semiconductor process and the active area is 1.3 mm . The TX achieves 0-dBm output power with a maximum data rate of 4 Mb/s/2 Mb/s and dissipates 2.7-mA/5.4-mA current from a 1.8-V power supply for on-off keying/frequency-shift keying modulation, respectively. The corresponding energy efficiency is 1.2 nJ/b mW and 4.8 nJ/b mW when normalized to the transmitting power.
Autors: Zhang, Q.;Feng, P.;Geng, Z.;Yan, X.;Wu, N.;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Feb 2011, volume: 5, issue:1, pages: 39 - 47
Publisher: IEEE
 
» A 2.6 nW, 0.45 V Temperature-Compensated Subthreshold CMOS Voltage Reference
Abstract:
A voltage reference circuit operating with all transistors biased in weak inversion, providing a mean reference voltage of 257.5 mV, has been fabricated in 0.18 m CMOS technology. The reference voltage can be approximated by the difference of transistor threshold voltages at room temperature. Accurate subthreshold design allows the circuit to work at room temperature with supply voltages down to 0.45 V and an average current consumption of 5.8 nA. Measurements performed over a set of 40 samples showed an average temperature coefficient of 165 ppm/ C with a standard deviation of 100 ppm/ C, in a temperature range from 0 to 125 C. The mean line sensitivity is 0.44%/V, for supply voltages ranging from 0.45 to 1.8 V. The power supply rejection ratio measured at 30 Hz and simulated at 10 MHz is lower than 40 dB and 12 dB, respectively. The active area of the circuit is 0.043 mm .
Autors: Magnelli, L.;Crupi, F.;Corsonello, P.;Pace, C.;Iannaccone, G.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 465 - 474
Publisher: IEEE
 
» A 228 W 750 MHz BPSK Demodulator Based on Injection Locking
Abstract:
An ultra-low-power BPSK demodulator based on injection locked oscillators (ILOs) is introduced in this paper. Two second harmonic ILOs are employed to convert BPSK signals to ASK signals, which are then demodulated by an envelope detector to baseband. For sub-GHz applications, the ILOs are implemented using ring oscillators to allow compact chip area and ultra-low power dissipation. Bit error rate (BER) analysis of this demodulator indicates erroneous polarity flipping of demodulated bits due to phase noise of ILO. The prototype chip is fabricated in a 65 nm CMOS technology that consumes 228 W of power and occupies 0.014 mm of die area. Measurement results reveal the demodulation of 750 MHz 5 Mb/S differential BPSK signal with sensitivity of 43 dBm. Theoretical BER analysis has been verified with erroneous flipping observed in the measurement and its probability close to the prediction.
Autors: Zhu, Q.;Xu, Y.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 416 - 423
Publisher: IEEE
 
» A 24-Channel, 300 Gb/s, 8.2 pJ/bit, Full-Duplex Fiber-Coupled Optical Transceiver Module Based on a Single “Holey” CMOS IC
Abstract:
We report here on the design, fabrication, and high-speed performance of a compact 48-channel optical transceiver module enabled by a key novel component: a “holey” Optochip. A single CMOS transceiver chip with 24 receiver (RX) and 24 laser diode driver circuits, measuring 5.2 mm 5.8 mm, becomes a holey Optochip with the fabrication of forty-eight through-substrate optical vias (holes): one for each transmitter (TX) and RX channel. Twenty-four channel, 850-nm VCSEL and photodiode arrays are directly flip-chip soldered to the Optochip with their active devices centered on the optical vias such that optical I/O is accessed through the substrate of the CMOS IC. The holey Optochip approach offers numerous advantages: 1) full compatibility with top emitting/detecting 850-nm VCSELs/PDs that are currently produced in high volumes; 2) close integration of the VCSEL/PD devices with their drive electronics for optimized high-speed performance; 3) a small-footprint, chip-scale package that minimizes CMOS die cost while maximizing transceiver packing density; 4) direct coupling to standard 4 12 multimode fiber arrays through a 2-lens optical system; and 5) straightforward scaling to larger 2-D arrays of TX and RX channels.
Autors: Schow, C. L.;Doany, F. E.;Rylyakov, A. V.;Lee, B. G.;Jahnes, C. V.;Kwark, Y. H.;Baks, C. W.;Kuchta, D. M.;Kash, J. A.;
Appeared in: Journal of Lightwave Technology
Publication date: Feb 2011, volume: 29, issue:4, pages: 542 - 553
Publisher: IEEE
 
» A 25 Gb/s(/km2) urban wireless network beyond IMT-advanced
Abstract:
In this article we present a survey on the technical challenges of future radio access networks beyond LTE-Advanced, which could offer very high average area throughput to support a huge demand for data traffic and high user density with energy-efficient operation. We highlight various potential enabling technologies and architectures to support the aggressive goal of average area throughput 25 Gb/s/km2 in beyond IMT-Advanced systems. Specifically, we discuss the challenges and solutions from the controlling/ processing perspective, the radio resource management perspective, and the physical layer perspective for dense urban cell deployment. Using various advanced technologies such as interference mitigation techniques, MIMO, and cooperative communications as well as crosslayer self-organizing networks, we show that future urban wireless networks could potentially offer high-quality mobile services and offer an experience similar to the wired Internet.
Autors: Sheng Liu;Jianjun Wu;Chung Ha Koh;Lau, V.K.N.;
Appeared in: IEEE Communications Magazine
Publication date: Feb 2011, volume: 49, issue:2, pages: 122 - 129
Publisher: IEEE
 
» A 3-D 160-Site Microelectrode Array for Cochlear Nucleus Mapping
Abstract:
A 3-D application-specific microelectrode array has been developed for physiological studies in guinea pig cochlear nucleus (CN). The batch-fabricated silicon probes contain integrated parylene cables and use a boron etch-stop to define 15μm-thick shanks and limit tissue displacement. Targeting the ventral (three probes) and dorsal (two probes) subnuclei, the custom four-shank 32-site probes are combined in a slotted block platform having a 1.18-mm footprint. The device has permitted, for the first time, high-density 3-D in vivo studies of ventral CN to dorsal CN connections, stimulating with 1000 μm sites in one subnucleus while recording with 177 μm sites in the other. Through these experiments, it has demonstrated the efficacy of bimodal silicon arrays to better understand the central nervous system at the circuit level. The 160 electrode sites also provide a high-density neural interface, which is an essential aspect of auditory prosthesis prototypes.
Autors: Merriam, S.;Dehmel, S.;Srivannavit, O.;Shore, S. E.;Wise, K. D.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Feb 2011, volume: 58, issue:2, pages: 397 - 403
Publisher: IEEE
 
» A 65 nm 0.165 fJ/Bit/Search 256 144 TCAM Macro Design for IPv6 Lookup Tables
Abstract:
Ternary content addressable memory (TCAM) is extensively adopted in network systems. As routing tables become larger, energy consumption and leakage current become increasingly important issues in the design of TCAM in nano-scale technologies. This work presents a novel 65 nm energy-efficient TCAM macro design for IPv6 applications. The proposed TCAM employs the concept of architecture and circuit co-design. To achieve an energy-efficient TCAM architecture, a butterfly match-line scheme and a hierarchy search-line scheme are developed to reduce significantly both the search time and power consumption. The match-lines are also implemented using noise-tolerant XOR-based conditional keepers to reduce not only the search time but also the power consumption. To reduce the increasing leakage power in advanced technologies, the proposed TCAM design utilizes two power gating techniques, namely super cut-off power gating and multi-mode data-retention power gating. An energy-efficient 256 144 TCAM macro is implemented using UMC 65 nm CMOS technology, and the experimental results demonstrate a leakage power reduction of 19.3% and an energy metric of the TCAM macro of 0.165 fJ/bit/search.
Autors: Huang, P.-T.;Hwang, W.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Feb 2011, volume: 46, issue:2, pages: 507 - 519
Publisher: IEEE
 
» A Bayesian Lasso via reversible-jump MCMC
Abstract:
Variable selection is a topic of great importance in high-dimensional statistical modeling and has a wide range of real-world applications. Many variable selection techniques have been proposed in the context of linear regression, and the Lasso model is probably one of the most popular penalized regression techniques. In this paper, we propose a new, fully hierarchical, Bayesian version of the Lasso model by employing flexible sparsity-promoting priors. To obtain the Bayesian Lasso estimate, a reversible-jump MCMC algorithm is developed for joint posterior inference over both discrete and continuous parameter spaces. Simulations demonstrate that the proposed RJ-MCMC based Bayesian Lasso yields...
Autors: Xiaohui, Chen , Z., Jane Wang , Martin J., McKeown
Appeared in: Signal Processing
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A calibration method of detecting soil water content based on the information-sharing in wireless sensor network
Abstract:
 Research highlights: ? A method based on the information-sharing is proposed for soil water content detection in agriculture of WSN. ? In this paper, geostatistics is taken as the tool for the method, which should work on the premise that calibration models for the single sensor EC-5 were established using Least Squares Support Vector Machines on MatLAB (LS-SVMlab). ? Laboratory experiments and example analysis show that this method can effectively solve the contradiction between the detection precision and costs for water detection in wireless sensor network used in farmland, that is to reduce the detection costs and improve the accuracy on the premise of not increasing the cost of a single sensor.

Autors: In agricultural production, there is contradiction between the cost and accuracy of detection during the course of acquiring soil water content (?) online. This conflict is one of the core issues of automatic water-saving irrigation technology in agr
Appeared in: Computers and Electronics in Agriculture
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Capability Maturity Framework for Sustainable Information and Communication Technology
Abstract:
A consortium of leading organizations from industry, the nonprofit sector, and academia has developed and tested a framework for systematically assessing and improving sustainable information and communication technology (ICT) capabilities.
Autors: Donnellan, Brian;Sheridan, Charles;Curry, Edward;
Appeared in: IT Professional
Publication date: Feb 2011, volume: 13, issue:1, pages: 33 - 40
Publisher: IEEE
 
» A chaotic system based fragile watermarking scheme for image tamper detection
Abstract:
 Abstract: In the past few years, various fragile watermarking techniques have been proposed for image authentication and tamper detection. In this paper, a novel chaos based watermarking scheme for image authentication and tamper detection is proposed. Tamper localization and detection accuracy are two important aspects of the authentication watermarking schemes. Our scheme can detect any modification made to the image and can also indicate the specific locations that have been modified. To improve the security of the proposed scheme two chaotic maps are employed. Since chaotic maps are sensitive to initial values, the corresponding position relation between pixels in the watermarked...
Autors: Sanjay, Rawat , Balasubramanian, Raman
Appeared in: AEU - International Journal of Electronics and Communications
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Charge Trap Folded nand Flash Memory Device With Band-Gap-Engineered Storage Node
Abstract:
A charge trap folded nand (Fnand ) Flash memory device with band-gap-engineered (BE) storage node is proposed. Because of the compact cell layout without junction contacts, a nand Flash memory is the most suitable memory medium for electronic appliances. Two memory cells are put together to have a common vertical channel, which enables one to achieve a theoretical near-30-nm technology. The resulting array is made by folding the conventional 2-D Flash memory and is called Fnand. The memory storage node uses a BE stack structure, where the oxide–nitride–oxide multilayers replace the tunnel oxide. The fin structures for both wordline and bitline have been formed by sidewall spacer patterning, instead of photolithography. The fabrication processes for SONONOS nand Flash memory having independent double gates are explained. Electrical characteristics regarding memory operations under paired cell interference are analyzed.
Autors: Cho, S.;Shim, W. B.;Kim, Y.;Yun, J.-G.;Lee, J. D.;Shin, H.;Lee, J.-H.;Park, B.-G.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2011, volume: 58, issue:2, pages: 288 - 295
Publisher: IEEE
 
» A CMOS low noise amplifier with integrated front-side micromachined inductor
Abstract:
The paper presents the design and characterization of a low noise amplifier (LNA) in a 0.18?m CMOS process with a novel micromachined integrated stacked inductor. The inductor is released from the silicon substrate by a low-cost CMOS compatible dry front-side micromachining process that enables higher inductor quality factor and self-resonance frequency. The post-processed micromachined inductor is used in the matching network of a single stage cascode 4GHz LNA to improve its RF performance. This study compares performance of the fabricated LNA prior to and after post-processing of the inductor. The measurement results show a 0.5dB improvement in the minimum noise...
Autors: Roee, Ben Yishay , Sara, Stolyarova , Shye, Shapira , Moshe, Musiya , David, Kryger , ...
Appeared in: Microelectronics Journal
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Compact Model for Threshold Voltage of Surrounding-Gate MOSFETs With Localized Interface Trapped Charges
Abstract:
Based on the perimeter-weighted-sum method and scaling theory, a compact threshold voltage model for surrounding-gate MOSFETs with localized interface trapped charges is developed by considering the effects of equivalent oxide charges on the flat-band voltage. The model shows how various charge conditions such as the positive/negative trapped charges and device structure parameters such as the silicon thickness, oxide thickness, and channel length affect the threshold voltage behavior. The model is verified by the 3-D device simulator and can be efficiently used to explore hot-carrier-induced threshold voltage degradation of the charge-trapped memory device.
Autors: Chiang, T.-K.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Feb 2011, volume: 58, issue:2, pages: 567 - 571
Publisher: IEEE
 
» A comparison between the Denavit-Hartenberg and the screw-based methods used in kinematic modeling of robot manipulators
Abstract:
This paper aims to integrate didactically some engineering concepts to understand and teach the screw-based methods applied to the kinematic modeling of robot manipulators, including a comparative analysis between these and the Denavit-Hartenberg-based methods. In robot analysis, kinematics is a fundamental concept to understand, since most robotic mechanisms are essentially designed for motion. The kinematic modeling of a robot manipulator describes the relationship between the links and joints that compose its kinematic chain. To do so, the most popular methods use the Denavit-Hartenberg convention or its variations, presented by several author and robot publications. This uses a minimal parameter representation...
Autors: C.R., Rocha , C.P., Tonetto , A., Dias
Appeared in: Robotics and Computer-Integrated Manufacturing
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Comparison of Different Frequency Scanning Methods for Study of Subsynchronous Resonance
Abstract:
This paper compares four different methods for determining the electrical damping of a power system seen from one generator as a function of frequency. This information is useful when the risk for subsynchronous resonance (SSR) in the system is evaluated. The study compares one frequency scanning method which is implemented in a time-domain digital simulation program with three methods of different complexity based on analytical calculations. The time-domain simulation method is easily implemented with a detailed model of the power system including complex load and generator models, whereas the analytical methods are based on simpler models of the power system. The computational effort is much larger for the time-domain method than for the analytical methods. In the study, all methods were used to determine the damping characteristics of a four-machine power system in different configurations. The study shows that fast analytical methods may provide results which closely agree with the detailed method of time-domain simulation. However, the study also shows that the level of accuracy in the analytical model is very important.
Autors: Johansson, N.;Angquist, L.;Nee, H.-P.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Feb 2011, volume: 26, issue:1, pages: 356 - 363
Publisher: IEEE
 
» A Complete Set of Linear-Phase Basis Functions for Scatterers With Flat Faces and for Planar Apertures
Abstract:
Entire-domain basis functions are introduced for the analysis of scattering from bodies with flat portions, and of radiation from planar apertures; they are defined via the application of the sampling theorem of Shannon. These basis functions are particularly convenient for polygonal contours; however, arbitrary contours can be treated in the same framework with a very minor pre-processing time. A non-redundant set of basis functions is determined a priori by explicit approximate formulas either for currents and for radiated field. Numerical results are presented to shown the accuracy of the method.
Autors: Casaletti, M.;Maci, S.;Vecchi, G.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Feb 2011, volume: 59, issue:2, pages: 563 - 573
Publisher: IEEE
 
» A Comprehensive Analysis of the MAC Unreliability Problem in IEEE 802.15.4 Wireless Sensor Networks
Abstract:
Wireless Sensor Networks (WSNs) represent a very promising solution in the field of wireless technologies for industrial applications. However, for a credible deployment of WSNs in an industrial environment, four main properties need to be fulfilled, i.e., energy efficiency, scalability, reliability, and timeliness. In this paper, we focus on IEEE 802.15.4 WSNs and show that they can suffer from a serious unreliability problem. This problem arises whenever the power management mechanism is enabled for energy efficiency, and results in a very low packet delivery ratio, also when the number of sensor nodes in the network is very low (e.g., 5). We carried out an extensive analysis—based on both simulation and experiments on a real WSN—to investigate the fundamental reasons of this problem, and we found that it is caused by the contention-based Medium Access Control (MAC) protocol used for channel access and its default parameter values. We also found that, with a more appropriate MAC parameters setting, it is possible to mitigate the problem and achieve a delivery ratio up to 100%, at least in the scenarios considered in this paper. However, this improvement in communication reliability is achieved at the cost of an increased latency, which may not be acceptable for industrial applications with stringent timing requirements. In addition, in some cases this is possible only by choosing MAC parameter values formally not allowed by the standard.
Autors: Anastasi, G.;Conti, M.;Di Francesco, M.;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2011, volume: 7, issue:1, pages: 52 - 65
Publisher: IEEE
 
» A Computational Framework for Uncertainty Quantification and Stochastic Optimization in Unit Commitment With Wind Power Generation
Abstract:
We present a computational framework for integrating a state-of-the-art numerical weather prediction (NWP) model in stochastic unit commitment/economic dispatch formulations that account for wind power uncertainty. We first enhance the NWP model with an ensemble-based uncertainty quantification strategy implemented in a distributed-memory parallel computing architecture. We discuss computational issues arising in the implementation of the framework and validate the model using real wind-speed data obtained from a set of meteorological stations. We build a simulated power system to demonstrate the developments.
Autors: Constantinescu, E. M.;Zavala, V. M.;Rocklin, M.;Lee, S.;Anitescu, M.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Feb 2011, volume: 26, issue:1, pages: 431 - 441
Publisher: IEEE
 
» A computationally efficient compact model for fully-depleted SOI MOSFETs with independently-controlled front- and back-gates
Abstract:
 Research highlights: ? A computationally efficient approximation for surface potential in FDSOI MOSFETs is developed. ? I-V and C-V models for FDSOI MOSFETs are derived without making the charge sheet approximation. ? The core model and non-ideal effect expressions are implemented in Verilog-A language. ? The model is symmetric with respect to Vds=0 and continuous in all regions of operation.

Autors: In this paper a computationally efficient surface-potential-based compact model for fully-depleted SOI MOSFETs with independently-controlled front- and back-gates is presented. A fully-depleted SOI MOSFET with a back-gate is essentially an independen
Appeared in: Solid-State Electronics
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A constant-speed lowering mechanism for the crucibles
Abstract:
The crystal growth characteristics of a certain material can be considerably influenced by the strain present in the growing crystal. Strain can be induced in various ways. One of the most common methods always presents in industrial processes, where attrition processes are always accompanied by generation of mechanical strain in a newly formed small crystal fragment obtained by mechanical stressing during preparation and handling. For this purpose, we have developed an apparatus which comprises a specially designed constant, special lowering device. The system was constructed for use with a Bridgeman furnace made in the laboratory for the crystal growth. The apparatus has been used with a variety of growth assemblies to grow crystals of materials with melting points in the range of 100–1000°C.
Autors: Bangaru, S.;Muralidharan, G.;
Appeared in: Review of Scientific Instruments
Publication date: Feb 2011, volume: 82, issue:2, pages: 025101 - 025101-5
Publisher: IEEE
 
» A continuous optimization framework for hybrid system identification?
Abstract:
We propose a new framework for hybrid system identification, which relies on continuous optimization. This framework is based on the minimization of a cost function that can be chosen as either the minimum or the product of loss functions. The former is inspired by traditional estimation methods, while the latter is inspired by recent algebraic and support vector regression approaches to hybrid system identification. In both cases, the identification problem is recast as a continuous optimization program involving only the real parameters of the model as variables, thus avoiding the use of discrete optimization. This program can be solved efficiently...
Autors: Fabien, Lauer , Gérard, Bloch , René, Vidal
Appeared in: Automatica
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Cooperative Sensing Based Cognitive Relay Transmission Scheme Without a Dedicated Sensing Relay Channel in Cognitive Radio Networks
Abstract:
In this correspondence, we investigate a selective relay spectrum sensing and best relay data transmission (SRSS-BRDT) scheme for multiple-relay cognitive radio networks. Specifically, in the spectrum sensing phase, only selected cognitive relays are utilized to transmit/forward their initial detection results (without a dedicated sensing relay channel) to a cognitive source for fusion, where the dedicated sensing channel refers to the channel transmitting initial spectrum sensing results from cognitive relays to the cognitive source. In the data transmission phase, only the best relay is selected to assist the cognitive source for its data transmissions. By jointly considering the two phases, we derive a closed-form expression of the outage probability for the SRSS-BRDT scheme over Rayleigh fading channels. We show that the SRSS-BRDT scheme outperforms the traditional cognitive transmission scheme (with a limited dedicated sensing channel) in terms of the outage probability performance. In addition, numerical results illustrate that the outage probability of the SRSS-BRDT scheme can be minimized through an optimal allocation of the time durations between the spectrum sensing and data transmission phases.
Autors: Zou, Y.;Yao, Y.-D.;Zheng, B.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Feb 2011, volume: 59, issue:2, pages: 854 - 858
Publisher: IEEE
 
» A criterion for UV detection of AC corona inception in a rod-plane air gap
Abstract:
This paper presents a series of experimental investigations involving the use of ultraviolet (UV) detection of corona discharges from a rod-plane air gap subjected to high AC voltages. To establish a criterion to identify the beginning of dangerous levels of corona discharges, using UV images, coronas from air gaps of various lengths were observed using a UV camera located at a fixed position, and coronas from an air gap with a fixed gap length were recorded from various observation distances. The corresponding UV images were then analyzed via an image-processing method developed by the authors. In the processed UV images, the area ratio of the UV discharge zone to the total region of interest was defined as an indicator of the intensity of corona discharges. Test results revealed that for different corona discharges, their developing stages could be uniquely described using attenuation in the intensity of the corona UV image with observation distance. Based on the findings, a criterion is proposed for the detection of corona inception. An onsite application of the proposed method and criterion is provided and discussed.
Autors: Zhou, W.;Li, H.;Yi, X.;Tu, J.;Yu, J.;
Appeared in: IEEE Transactions on Dielectrics and Electrical Insulation
Publication date: Feb 2011, volume: 18, issue:1, pages: 232 - 237
Publisher: IEEE
 
» A Custom-Design Data Logger Core for Physiological Signal Recording
Abstract:
Large data volumes are generated in physiological signal loggers so that the available memory becomes a limiting factor, particularly in small-size wearable applications. This paper demonstrates the practicality of using a programmable logic device as controller for MultiMediaCard memory for implementing a data logger, which can ultimately be realized as a fully integrated circuit. A minimum configuration in terms of complexity, cost, and size is sought using a minimal subset of the serial peripheral interface protocol and minimum overhead. The data bus frequency is linked to the converter clock, which ensures continuous data streaming with little implementation effort. The hardware realization of the controller in a 0.18-μm CMOS process occupies 0.014 mm2. The measured results confirm the performance of the logger using the electrocardiogram as a representative signal.
Autors: Rieger, R.;Yan-Ru Huang;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2011, volume: 60, issue:2, pages: 532 - 538
Publisher: IEEE
 
» A Delay-Dependent Dual-Rate PID Controller Over an Ethernet Network
Abstract:
In this paper, a methodology to design controllers able to cope with different load conditions on an Ethernet network is introduced. Load conditions induce time-varying delays between measurements and control. To face these variations an interpolated, delay-dependent gain scheduling law is used. The lack of synchronization is solved by adopting an event-based control approach. The dual-rate control action computation is carried out at a remote controller, whereas control actions and measurements are taken out locally at the controlled process site. Stability is proved in terms of probabilistic linear matrix inequalities. TrueTime simulations in an Ethernet case show the benefit of the proposal, which is later validated on an experimental test-bed Ethernet environment.
Autors: Cuenca, Á.;Salt, J.;Sala, A.;Piza, R.;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2011, volume: 7, issue:1, pages: 18 - 29
Publisher: IEEE
 
» A demand response based solution for LMP management in power markets
Abstract:
 Research highlights: ? DSM programs have been effective to address LMPs in the market and system operators experience. ? These programs can help ISO to reduce price volatility during peak demand hours. ? The effects of demand response program on LMP spikes and operation cost reduction are evaluated.

Autors: In recent years, most of the countries around the world have gone through the power system restructuring process. Along with this restructuring in power market there are some issues like LMP problems that need to be solved base on demand response. In
Appeared in: International Journal of Electrical Power & Energy Systems
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Dictionary-Driven P300 Speller With a Modified Interface
Abstract:
P300 spellers are mainly composed of an interface, by which alphanumerical characters are presented to users, and a classification system, which identifies the target character by using acquired EEG data. In this study, we proposed modifications both to the interface and to the classification system, in order to reduce the number of required stimulus repetitions and consequently boost the information transfer rate. We initially incorporated a custom-built dictionary into the classification system, and conducted a study on 14 healthy subjects who copy-spelled 15 four letter words. Incorporating the dictionary, the mean accuracy at five trials increased from 72.86% to 95.71%. To further increase the system performance, we first validated the hypothesis that for a conventional P300 system, most target-error pairs lie on the same row or column. Then based on the validated hypothesis, we adjusted letter positions on the well-known from A to Z interface. The same subjects spelled the same 15 words using the modified interface as well, and the mean information transfer rate at two trials reached 55.32 bits/min.
Autors: Ahi, S. T.;Kambara, H.;Koike, Y.;
Appeared in: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Publication date: Feb 2011, volume: 19, issue:1, pages: 6 - 14
Publisher: IEEE
 
» A Differential Geometric Approach to Automated Segmentation of Human Airway Tree
Abstract:
Airway diseases are frequently associated with morphological changes that may affect the physiology of the lungs. Accurate characterization of airways may be useful for quantitatively assessing prognosis and for monitoring therapeutic efficacy. The information gained may also provide insight into the underlying mechanisms of various lung diseases. We developed a computerized scheme to automatically segment the 3-D human airway tree depicted on computed tomography (CT) images. The method takes advantage of both principal curvatures and principal directions in differentiating airways from other tissues in geometric space. A “puzzle game” procedure is used to identify false negative regions and reduce false positive regions that do not meet the shape analysis criteria. The negative impact of partial volume effects on small airway detection is partially alleviated by repeating the developed differential geometric analysis on lung anatomical structures modeled at multiple iso-values (thresholds). In addition to having advantages, such as full automation, easy implementation and relative insensitivity to image noise and/or artifacts, this scheme has virtually no leakage issues and can be easily extended to the extraction or the segmentation of other tubular type structures (e.g., vascular tree). The performance of this scheme was assessed quantitatively using 75 chest CT examinations acquired on 45 subjects with different slice thicknesses and using 20 publicly available test cases that were originally designed for evaluating the performance of different airway tree segmentation algorithms.
Autors: Pu, J.;Fuhrman, C.;Good, W. F.;Sciurba, F. C.;Gur, D.;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Feb 2011, volume: 30, issue:2, pages: 266 - 278
Publisher: IEEE
 
» A Digital Gigapixel Large-Format Tile-Scan Camera
Abstract:
Emerging applications in virtual museums, cultural-heritage projects, and digital art preservation require high-quality, high-resolution imaging of objects with fine structure, shape, and texture. Large-format digital photography can provide such imaging. However, such photography presents unique challenges, particularly sensor-lens mismatch and extended depth of field. A new digital tile-scan large-format camera can acquire high-quality, high-resolution images of static scenes. It employs unique calibration techniques and a novel but simple algorithm for focal-stack processing of very large images with significant magnification variations. The camera automatically collects a set of overlapping focal stacks and processes them into a single high-resolution and extended-depth-of-field image.
Autors: Ben-Ezra, Moshe;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Feb 2011, volume: 31, issue:1, pages: 49 - 61
Publisher: IEEE
 
» A Discrete-Time Model for the Design of Type-II PLLs With Passive Sampled Loop Filters
Abstract:
Type-II charge-pump (CP) phase-locked loop (PLLs) are used extensively in electronic systems for frequency synthesis. Recently, a passive sampled loop filter (SLF) has been shown to offer major benefits over the conventional continuous-time loop filter traditionally used in such PLLs. These benefits include greatly enhanced reference spur suppression, elimination of CP pulse-position modulation nonlinearity, and, in the case of phase noise cancelling fractional- PLLs, improved phase noise cancellation. The main disadvantage of the SLF to date has been the lack of a linear time-invariant (LTI) model with which to perform the system-level design of SLF-based PLLs. Without such a model, designers are forced to rely on trial and error iteration supported by lengthy transient simulations. This paper presents an accurate LTI model of SLF-based type-II PLLs that eliminates this disadvantage.
Autors: Wang, K. J.;Galton, I.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Feb 2011, volume: 58, issue:2, pages: 264 - 275
Publisher: IEEE
 
» A discrete-time observer design for spacecraft attitude determination using an orthogonality-preserving algorithm?
Abstract:
This paper studies a nonlinear discrete-time partial state observer design problem for rigid spacecraft systems, particularly for spacecraft attitude estimation. The construction is inspired by an orthogonality-preserving numerical algorithm, and it yields a semiglobal practical asymptotic observer. We show that the separation principle holds, and hence stabilization using output feedback is possible. An example is provided to illustrate the usefulness of our results in a sampled-data implementation of an attitude control for a rigid spacecraft using output feedback and to illustrate the advantages of the proposed observer design, especially compared to a sample and hold version of a similar type...
Autors: Dina Shona, Laila , Marco, Lovera , Alessandro, Astolfi
Appeared in: Automatica
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Distributed Algorithm for Proportional Task Allocation in Networks of Mobile Agents
Abstract:
In a proportional task allocation problem, it is desired for robotic agents to have equal duty to capability ratios. Here, this problem is addressed as a combination of deployment and consensus problems. Tasks occur in a convex region and each task is assigned to its nearest agent. Agents are deployed on this area in order to reach consensus over the value of their duty to capability ratio. A distributed, asynchronous, and scalable algorithm is presented for solving this problem in continuous time domain.
Autors: Sayyaadi, H.;Moarref, M.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2011, volume: 56, issue:2, pages: 405 - 410
Publisher: IEEE
 
» A Distributed Multiarea State Estimation
Abstract:
This paper presents a new distributed state estimation method for multiarea power systems. Each area performs its own state estimation, using local measurements, and exchanges border information (estimated boundary states and measurements) at a coordination state estimator, which computes the system-wide state. Furthermore, observability and bad data analysis are accomplished in a distributed manner. The proposed method is illustrated with the IEEE 14-bus system. Test results with the IEEE 118-bus system are given.
Autors: Korres, G. N.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Feb 2011, volume: 26, issue:1, pages: 73 - 84
Publisher: IEEE
 
» A Double-Edged Sword: The Effects of Challenge and Hindrance Time Pressure on New Product Development Teams
Abstract:
Bringing new products to market requires team effort. New product development teams often face demanding schedules and high deliverable expectations, making time pressure a common experience at the workplace. Past literature have generally associated the relationship between time pressure and performance based on the inverted-U model, where low and high levels of time pressure are related to poor performance. However, teams do not necessarily perform worse when the levels of time pressure are high. In contrast, there are numerous examples of high-performance teams in intense time-pressure situations. The purpose of this study is to reconcile some of the discrepancies concerning the effects of time pressure by considering the nature of stress. This study is also designed to investigate time pressure at team level—an area that is not well investigated. A model of 2-D time pressure, i.e., challenge and hindrance time pressure, was developed. Data are collected based on a two-part electronic survey from 81 new product development teams (500 respondents) in Western Europe. The results showed challenge and hindrance time pressure to improve and deteriorate team performance, respectively. At the same time, we also found team coordination to partially mediate the time-pressure–team-performance relationships. Furthermore, team identification is found to sustain team coordination, especially for teams facing hindrance time pressure. This indicates that teams that possess strong team identification could be positioned strategically in projects where time pressure is intense and where the stakes are high. Other implications with respect to theory and practice are discussed.
Autors: Chong, D. S. F.;Eerde, W. V.;Chai, K. H.;Rutte, C. G.;
Appeared in: IEEE Transactions on Engineering Management
Publication date: Feb 2011, volume: 58, issue:1, pages: 71 - 86
Publisher: IEEE
 
» A Driving Technology for Retrofit LED Lamp for Fluorescent Lighting Fixtures With Electronic Ballasts
Abstract:
A driving technique that can operate with electronic ballasts for fluorescent lamps to drive LEDs without requiring the replacing of any electronic ballast circuitry or modifying the existing infrastructure of a lighting network is presented. This technology provides an eco-friendly and immediate solution to turn a lighting system with fluorescent lamps into the one with LED lamps. The proposed technology is based on controlling the input impedance of an ac/dc converter, which is connected to the output of the ballast, and converting the high-frequency ac power from the ballast into dc power for the LEDs. With such adjustable input impedance, the active and reactive power drawn from the ballast can be controlled. The power supplying to the LED lamp, and thus its brightness, can be adjusted independently by an external means, such as wireless control. An experimental LED lamp prototype for retrofitting a 36-W T8 fluorescent lamp has been built. It is studied together with a fluorescent lamp and with both lamps ballasted by a commercial nondimmable electronic ballast for dual fluorescent lamps. The light output of the LED lamp can be varied from 100% to 51% of full brightness, while the light output of the fluorescent lamp remains unchanged. The input power to the ballast is reduced by 26% over the dimming operation of the LED lamp. A comprehensive study into the electrical performance of the ballast, operational characteristics of the two lamps, system efficiencies, and light outputs under different dimmed conditions is presented.
Autors: Chen, N.;Chung , H. S.-H.;
Appeared in: IEEE Transactions on Power Electronics
Publication date: Feb 2011, volume: 26, issue:2, pages: 588 - 601
Publisher: IEEE
 
» A Dual Modality System for Simultaneous Fluorescence and Positron Emission Tomography Imaging of Small Animals
Abstract:
A dual-modality imaging system for simultaneous fluorescence molecular tomography (FMT) and positron emission tomography (PET) of small animals has been developed. The system consists of a noncontact 360 -projection FMT module and a flat panel detector pair based PET module, which are mounted orthogonally for the sake of eliminating cross interference. The FMT images and PET data are simultaneously acquired by employing dynamic sampling mode. Phantom experiments, in which the localization and range of radioactive and fluorescence probes are exactly indicated, have been carried out to verify the feasibility of the system. An experimental tumor-bearing mouse is also scanned using the dual-modality simultaneous imaging system, the preliminary fluorescence tomographic images and PET images demonstrate the in vivo performance of the presented dual-modality system.
Autors: Liu, S.;Zhang, B.;Wang, X.;Li, L.;Chen, Y.;Liu, X.;Liu, F.;Shan, B.;Bai, J.;
Appeared in: IEEE Transactions on Nuclear Science
Publication date: Feb 2011, volume: 58, issue:1, pages: 51 - 57
Publisher: IEEE
 
» A Dynamic Voltage Restorer Equipped With a High-Frequency Isolated DC–DC Converter
Abstract:
This paper presents a dynamic voltage restorer (DVR) that is characterized by the use of a high-frequency unidirectional isolated dc–dc converter. A traditional DVR has a large and bulky series transformer even for three-phase low-voltage up to 480-V applications because the transformer operates at the line frequency (50 or 60 Hz). The emergence of state-of-the-art semiconductor devices and magnetic cores has driven power electronic engineers to develop compact high-frequency isolated dc–dc converters. This paper discusses the control and performance of a low-voltage DVR using a high-frequency isolated dc–dc converter. The high-frequency (20-kHz) transformer in the dc–dc converter is much smaller, for example, one-hundredth, in volume than the line-frequency transformer. Moreover, connecting the shunt converter to the load side brings a significant reduction in energy-storage capacity to the DVR. Experimental results obtained from a three-phase three-wire 200-V 5-kW laboratory system confirm the viability and effectiveness of the system configuration.
Autors: Jimichi, T.;Fujita, H.;Akagi, H.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Feb 2011, volume: 47, issue:1, pages: 169 - 175
Publisher: IEEE
 
» A Fast Analog Circuit Analysis Algorithm for Design Modification and Verification
Abstract:
This paper presents a fast analog circuit analysis algorithm, fundamental circuit-based circuit analysis, for circuits being repeatedly modified and verified in product development. The algorithm reuses previous circuit simulation result on successive changed circuit analysis to achieve simulation operation reduction. The algorithm is implemented with SPICE simulator on linear and nonlinear circuit applications with the proposed device delta models. The experiments show that the algorithm increases the speed of the circuit simulation five to ten times over directly simulations under the same simulation accuracy.
Autors: Zhou, T. Y.;Liu, H.;Zhou, D.;Tarim, T.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Feb 2011, volume: 30, issue:2, pages: 308 - 313
Publisher: IEEE
 
» A fast nonlinear control method for linear systems with input saturation?
Abstract:
We present a novel, fast saturating nonlinear feedback law for single input systems with linear dynamics and input saturation. It is fast in the sense that it yields a better performance than a saturating linear control law. The control law is based on implicit soft variable-structure control. A convex optimization procedure for the controller synthesis based on linear matrix inequalities (LMIs) is derived at the price of some conservatism. As an example, we consider the control of a submarine.
Autors: Hendrik, Lens , Jürgen, Adamy , Dilyana, Domont-Yankulova
Appeared in: Automatica
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Feature-Based Solution to Forward Problem in Electrical Capacitance Tomography of Conductive Materials
Abstract:
A new feature-based technique is introduced to solve the nonlinear forward problem (FP) of the electrical capacitance tomography with the target application of monitoring the metal fill profile in the lost foam casting process. The new technique is based on combining a linear solution to the FP and a correction factor (CF). The CF is estimated using an artificial neural network (ANN) trained using key features extracted from the metal distribution. The CF adjusts the linear solution of the FP to account for the nonlinear effects caused by the shielding effects of the metal. This approach shows promising results and avoids the curse of dimensionality through the use of features and not the actual metal distribution to train the ANN. The ANN is trained using nine features extracted from the metal distributions as input. The expected sensors readings are generated using ANSYS software. The performance of the ANN for the training and testing data was satisfactory, with an average root-mean-square error equal to 2.2%.
Autors: Abdelrahman, M. A.;Gupta, A.;Deabes, W. A.;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Feb 2011, volume: 60, issue:2, pages: 430 - 441
Publisher: IEEE
 
» A Few Words from the Incoming President [President's Column]
Abstract:
As the 2011 president of the IEEE Microwave Theory and Techniques Society (MTT-S), I appreciate the opportunity to add a few words to those of Prof. El-Ghazaly, my 2010 predecessor and very good friend.
Autors: Snyder, R.;
Appeared in: IEEE Microwave Magazine
Publication date: Feb 2011, volume: 12, issue:1, pages: 12 - 16
Publisher: IEEE
 
» A Filtered Repetitive Controller for a Class of Nonlinear Systems
Abstract:
In this note, a filtered repetitive controller (FRC) is designed to compensate for periodic disturbances in a class of nonlinear systems. First, a new model of periodic disturbances is proposed. By this model, the FRC is designed and the resulting closed-loop error dynamics are analyzed with the help of a Lyapunov-Krasovskii functional. Finally the method is applied to periodic disturbance rejection in a class of robotic manipulators. Compared with repetitive controllers, the FRC provides the flexibility to choose filter parameters to achieve a tradeoff between tracking performance and stability. More importantly, FRC can deal with small input delay while the corresponding RC cannot.
Autors: Quan, Q.;Cai, K.-Y.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Feb 2011, volume: 56, issue:2, pages: 399 - 405
Publisher: IEEE
 
» A frequentist approach to mapping under uncertainty?
Abstract:
An asynchronous stochastic approximation based (frequentist) approach is proposed for mapping using noisy mobile sensors under two different scenarios: (1) perfectly known sensor locations and (2) uncertain sensor locations. The frequentist methodology has linear complexity in the map components, is immune to the data association problem and is provably consistent. The frequentist methodology, in conjunction with a Bayesian estimator, is applied to the Simultaneous Localization and Mapping (SLAM) problem of Robotics. Several large maps are estimated using the hybrid Bayesian/Frequentist scheme and results show that the technique is robust to the computational and performance issues inherent in the purely Bayesian...
Autors: S., Chakravorty , R., Saha
Appeared in: Automatica
Publication date: Feb 2011
Publisher: Elsevier B.V.
 
» A Fully Integrated CMOS 800-mW Four-Phase Semiconstant ON/OFF-Time Step-Down Converter
Abstract:
A fully integrated dc–dc four-phase step-down converter in a 130-nm 1.2-V CMOS technology is realized with integrated metal-track inductors and integrated MOS and MIM capacitors. The converter requires no external components and is designed to generate an output voltage of out of a supply voltage. The maximum power-conversion efficiency is 58%, for a voltage-conversion ratio of 0.46. This yields a 21% improvement over a linear converter. The maximum output power is and the power density of is in the same order of magnitude of nonintegrated switching converters, even when not taking their off-chip output filter into account. Stacked transistors are used to cope with the high voltage. A novel control system based on semiconstant ON/OFF time (SCOOT) regulates the output voltage. It also provides stability over the entire load range from 0 to 800 mW. The four-phase topology and the SCOOT control system ensure an output voltage ripple below 10% of the output voltage. The converter operates in discontinuous, synchronous switching mode. The switching frequency varies with the load from 75 kHz to 225 MHz.
Autors: Wens, M.;Steyaert, M. S. J.;
Appeared in: IEEE Transactions on Power Electronics
Publication date: Feb 2011, volume: 26, issue:2, pages: 326 - 333
Publisher: IEEE
 
» A Fundamental Linear Systems Conflict Between Performance and Passivity in Haptic Rendering
Abstract:
This paper analyzes inherent conflicts between model-matching goals of haptic rendering and passivity requirements for coupled stability. We apply results from complex analysis to prove that certain linear passive virtual environments cannot be rendered passively with a desired level of accuracy and over a given finite bandwidth. One practical consequence is that, under appropriate hypotheses, passivity will be violated when accurately rendering inertia in a virtual environment that is less than the inertia of the uncompensated hardware dynamics. In a related result, we show that there exists a waterbed-type tradeoff between performance and phase lag in the rendered dynamics. Both design constraints arise from feedback-bandwidth limitations and not sampled-data effects, quantization, or nonlinearities. The key to our analysis is an interpretation of a Bode gain–phase integral relationship that relates magnitude at low frequencies to phase at high frequencies. The performance limitation and the waterbed tradeoff are illustrated through an experimental study.
Autors: Griffiths, P. G.;Gillespie, R. B.;Freudenberg, J. S.;
Appeared in: IEEE Transactions on Robotics
Publication date: Feb 2011, volume: 27, issue:1, pages: 75 - 88
Publisher: IEEE
 
» A Fuzzy Clustering Algorithm for Virtual Character Animation Representation
Abstract:
The use of realistic humanoid animations generated through motion capture (MoCap) technology is widespread across various 3-D applications and industries. However, the existing compression techniques for such representation often do not consider the implicit coherence within the anatomical structure of a human skeletal model and lacks portability for transmission consideration. In this paper, a novel concept virtual character animation image (VCAI) is proposed. Built upon a fuzzy clustering algorithm, the data similarity within the anatomy structure of a virtual character (VC) model is jointly considered with the temporal coherence within the motion data to achieve efficient data compression. Since the VCA is mapped as an image, the use of image processing tool is possible for efficient compression and delivery of such content across dynamic network. A modified motion filter (MMF) is proposed to minimize the visual discontinuity in VCA's motion due to the quantization and transmission error. The MMF helps to remove high frequency noise components and smoothen the motion signal providing perceptually improved VCA with lessened distortion. Simulation results show that the proposed algorithm is competitive in compression efficiency and decoded VCA quality against the state-of-the-art VCA compression methods, making it suitable for providing quality VCA animation to low-powered mobile devices.
Autors: Chew, B.-S.;Chau, L.-P.;Yap, K.-H.;
Appeared in: IEEE Transactions on Multimedia
Publication date: Feb 2011, volume: 13, issue:1, pages: 40 - 49
Publisher: IEEE
 
» A Fuzzy Method for Global Quality Index Evaluation of Solder Joints in Surface Mount Technology
Abstract:
In recent years, the requirement of compact devices caused an increasing use of Surface Mount Technology. This technology guarantees the reduction of the size of electronic packages by exploiting solder joint interconnection technology. Nevertheless, parameter variations can occur during the deposition and printing of the soldering paste on a board, compromising its correct working. In this paper, it is proposed a fuzzy architecture for computing an index which provides a quantitative refined assessment about the quality of the soldered interconnections. This task is performed by reproducing the modus operandi of the human experts during their assessments. The proposed architecture consists of three modules connected in series: a feature extraction block and two fuzzy ones. The presented solution keeps the benefits of a neurofuzzy system previously proposed in literature, like the reduction of equipment and computational costs. Moreover, it implies two further advantages: the influence of the human experts in its design is reduced and its implementation is reasonable. Experimental results confirm such advantages, in fact, the architecture approximates the human assessments reliably.
Autors: Acciani, G.;Fornarelli, G.;Giaquinto, A.;
Appeared in: IEEE Transactions on Industrial Informatics
Publication date: Feb 2011, volume: 7, issue:1, pages: 115 - 124
Publisher: IEEE
 
» A Game-Theoretic Approach to Energy-Efficient Power Control and Receiver Design in Cognitive CDMA Wireless Networks
Abstract:
The uplink of a multiuser cognitive radio network, wherein secondary users communicating with a secondary access point coexist with primary users communicating with a primary access point, is considered in this paper. Primary and secondary users' signals coexist in the same frequency band, and the transmit powers of the secondary users are constrained so that the interference from the whole secondary network to each primary user does not exceed a prescribed threshold. Given this constraint, a noncooperative power control game for maximum energy efficiency with a fairness constraint on the maximum received powers for the secondary users has been considered. The considered game is shown to admit a unique Nash equilibrium, also in the case in which energy efficiency is maximized with respect to both transmit power and choice of the linear uplink receiver. Based on large system analysis, a one-shot procedure for computing the users' transmit powers at the Nash equilibrium with no need for iteration among users is also derived. Numerical simulations confirm the theoretical results on the existence and uniqueness of the Nash equilibrium, confirm the effectiveness of the results obtained through the large system analysis, and show that secondary users have a beneficial impact on the whole network throughput, at the price of a moderate degradation in the performance of the primary users.
Autors: Buzzi, S.;Saturnino, D.;
Appeared in: IEEE Journal of Selected Topics in Signal Processing
Publication date: Feb 2011, volume: 5, issue:1, pages: 137 - 150
Publisher: IEEE
 

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