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Electrical and Electronics Engineering publications abstract of: 09-2010 sorted by title, page: 0 |
| » 10-Gb/s Operation of RSOA Using a Delay Interferometer |
Abstract:
We report on the use of a delay interferometer (DI) to transmit 10-Gb/s optical signals from a 1.5-GHz-bandwidth reflective semiconductor optical amplifier (RSOA). The DI acts as a two-tap optical equalizer, compensating for the severe bandwidth limitation imposed by the RSOA. We demonstrate the successful transmission of 10.7-Gb/s nonreturn-to-zero signals over 50-km standard single-mode fiber with a 0.3-dB penalty. |
| Autors: Kim, H.; |
| Appeared in: IEEE Photonics Technology Letters |
| Publication date: Sep 2010, volume: 22, issue:18, pages: 1379 - 1381 |
| Publisher: IEEE |
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| » 10-Gb/s Optical Transceiver Using the Yuen 2000 Encryption Protocol |
Abstract:
A 10-Gb/s optical transceiver using the Yuen 2000 (Y-00) encryption protocol was developed. The key device in the transceiver, a 10-GS/s, 10-bit digital-to-analog converter (DAC) LSI, was fabricated using 0.25-$mu$m SiGe BiCMOS technology. Circuit techniques such as segmented architecture, parasitic capacitance separation using the base-common transistor, and the usage of a common mode logic (CML) driver were employed to minimize glitches. The Y-00 transceiver equipped with the DAC LSI operated at 10 Gb/s. Moreover, a 300-km transmission experiment performed at a data rate of 10 Gb/s proved that the developed transceiver can be used in a practical application when forward error correction is applied. |
| Autors: Ohhata, K.;Hirota, O.;Honda, M.;Akutsu, S.;Doi, Y.;Harasawa, K.;Yamashita, K.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2714 - 2723 |
| Publisher: IEEE |
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| » 1K Element Antenna System for Mobile Direct Broadcasting Satellite Reception |
Abstract:
This paper describes the design methodology and low-cost solutions implemented in a low-cost 1K–element phased array system for mobile direct broadcasting satellite (DBS) reception. The techniques and configurations used to reduce the cost and complexity of the system are described in this paper. Moreover, the design of a novel compact sub-array antenna to reduce the overall size of the system , the signal processing unit to suppress the noise on feedback channel and the mechanical structure to make the system agile, light and low cost are presented. Three efficient, model-free beamforming techniques are discussed and their performances in terms of convergence speed and steady state behavior are compared using several road tests. Results show that the developed intelligent antenna can meet the stringent requirements of the highly dynamic mobile applications. |
| Autors: Mousavi, P.;Fakharzadeh, M.;Safavi-Naeini, S.; |
| Appeared in: IEEE Transactions on Broadcasting |
| Publication date: Sep 2010, volume: 56, issue:3, pages: 340 - 349 |
| Publisher: IEEE |
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| » 205-GHz (Al,In)N/GaN HEMTs |
Abstract:
We report 55-nm gate AlInN/GaN high-electron-mobility transistors (HEMTs) featuring a short-circuit current gain cutoff frequency of $f_{T} = hbox{205 GHz}$ at room temperature, a new record for GaN-based HEMTs. The devices source a maximum current density of 2.3 A/mm at $V_{rm GS} = hbox{0 V}$ and show a measured transconductance of 575 mS/mm, which is the highest value reported to date for nonrecessed gate nitride HEMTs. Comparison to state-of-the-art thin-barrier AlGaN/GaN HEMTs suggests that AlInN/GaN devices benefit from an advantageous channel velocity under high-field transport conditions. |
| Autors: Sun, H.;Alt, A. R.;Benedickter, H.;Feltin, E.;Carlin, J.-F.;Gonschorek, M.;Grandjean, N. R.;Bolognesi, C. R.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 957 - 959 |
| Publisher: IEEE |
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| » 240-GHz Gain-Bandwidth Product Back-Side Illuminated AlInAs Avalanche Photodiodes |
Abstract:
We demonstrate an AlInAs–InGaAs separate absorption, grading, and multiplication avalanche photodiode (APD) with a very thin avalanche layer operating at 1550 nm for 10-Gb/s optical transmission achieving simultaneously high responsivity (0.9 A/W at ${M} = 1$), very low excess noise factor $({F}({M}=10) = 3)$, and very high gain-bandwidth product of 240 GHz. To our knowledge, this is the first time that a back-side illuminated planar junction AlInAs–InGaAs APD achieved such performances. |
| Autors: Lahrichi, M.;Glastre, G.;Derouin, E.;Carpentier, D.;Lagay, N.;Decobert, J.;Achouche, M.; |
| Appeared in: IEEE Photonics Technology Letters |
| Publication date: Sep 2010, volume: 22, issue:18, pages: 1373 - 1375 |
| Publisher: IEEE |
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| » 3-D Printers Proliferate [Hands On] |
Abstract:
For years, visionary engineers have been touting the idea of a cheap box about the size of a microwave oven that could build arbitrary solid objects out of plastic, ceramics, metal, ice, and even living cells. |
| Autors: Wallich, P.; |
| Appeared in: IEEE Spectrum |
| Publication date: Sep 2010, volume: 47, issue:9, pages: 23 - 23 |
| Publisher: IEEE |
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| » 3-D Spot Modeling for Automatic Segmentation of cDNA Microarray Images |
Abstract:
Spot segmentation—the second essential stage of cDNA microarray image analysis—constitutes a challenging process. At present, several up-to-date spot-segmentation techniques or software programs—proposed in the literature—are often characterized as “automatic.” On the contrary, they are in effect not fully automatic since they require human intervention in order to specify mandatory input parameters or to correct their results. Human intervention, however, can inevitably modify the actual results of the cDNA microarray experiment and lead to erroneous biological conclusions. Therefore, the development of an automated spot-segmentation process becomes of exceptional interest. In this paper, an original and fully automatic approach to accurately segmenting the spots in a cDNA microarray image is presented. In order for the segmentation to be accomplished, each real spot of the cDNA microarray image is represented in a three-dimensional (3-D) space by a 3-D spot model. Each 3-D spot model is determined via an optimization problem, which is solved by using a genetic algorithm. The segmentation of real spots is conducted by drawing the contours of their 3-D spot models. The proposed method has been compared with various published and established techniques, using several synthetic and real cDNA microarray images that contain thousands of spots. The outcome has shown that the proposed method outperforms prevalent existing techniques. It is also noise resistant and yields excellent results even under adverse conditions such as the appearance of spots of various sizes and shapes. |
| Autors: Zacharia, E.;Maroulis, D. E.; |
| Appeared in: IEEE Transactions on NanoBioscience |
| Publication date: Sep 2010, volume: 9, issue:3, pages: 181 - 192 |
| Publisher: IEEE |
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»  Ferroelectric Thin-Film Capacitors for Flexible Nonvolatile Memory Applications |
Abstract:
This letter reports the fabrication of $hbox{PbZr}_{x}hbox{Ti}_{1-x} hbox{O}_{3}$ (PZT) thin-film capacitors on flexible plastic substrates. The PZT film was formed on a wafer using a sol–gel method and transferred to a thin plastic substrate using an elastomeric stamp. The PZT film on the plastic substrate showed a well-saturated hysteresis loop with a $P_{r}$ of $sim!hbox{20} muhbox{C}/hbox{cm}^{2}$ and a $V_{c}$ of $ sim$1.1 V at a supplied voltage of 3 V, which are similar to those observed for PZT films on rigid wafers, as well as stable operation under an 8-mm bending radius. These characteristics suggest promising applications in flexible electronic systems. |
| Autors: Rho, J.;Kim, S. J.;Heo, W.;Lee, N-E.;Lee, H-S.;Ahn, J-H.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 1017 - 1019 |
| Publisher: IEEE |
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»  Method for Threshold Voltage Extraction Applicable in Advanced MOSFETs With Nonlinear Behavior Above Threshold |
Abstract:
A method is proposed for determining the threshold voltage in a MOSFET, based on the derivative of the $g_{m}/I_{rm d}$ ratio with respect to the gate voltage, which theoretically originates from the unified charge-control model similar to the capacitance-derivative method. This yields threshold voltages significantly less affected by gate-voltage-dependent mobility and series resistance than linear-extrapolation techniques. Moreover, it is more physically adequate in the case of advanced MOSFETs with ultrathin dielectrics, thin SOI body, or double gate operation, featuring a gradual transition from the exponential to linear charge control. The robustness of the method is experimentally verified on FinFETs with different lengths. |
| Autors: Flandre, D.;Kilchytska, V.;Rudenko, T.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 930 - 932 |
| Publisher: IEEE |
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» A 0.13  SiGe BiCMOS Technology Featuring f  /f  of 240/330 GHz and Gate Delays Below 3 ps |
Abstract:
A 0.13 $mu{hbox {m}}$ SiGe BiCMOS technology for millimeter-wave applications is presented. This technology features high-speed HBTs with peak transit frequencies $f _{T}$ of 240 GHz, maximum oscillation frequencies $f _{max}$ of 330 GHz, and breakdown voltages ${rm BV}_{rm CEO}$ of 1.7 V along with high-voltage HBTs ($f _{T} =50~{hbox {GHz}}$, $f _{max} =130~{hbox {GHz}}$, ${rm BV}_{rm CEO} =3.7~{hbox{V}}$) integrated in a dual gate oxide RF-CMOS process. Ring oscillator gate delays of 2.9 ps, low-noise amplifiers for 122 GHz, and LC oscillators with fundamental-mode oscillation frequencies above 200 GHz are demonstrated. |
| Autors: Rucker, H.;Heinemann, B.;Winkler, W.;Barth, R.;Borngraber, J.;Drews, J.;Fischer, G. G.;Fox, A.;Grabolla, T.;Haak, U.;Knoll, D.;Korndorfer, F.;Mai, A.;Marschmeyer, S.;Schley, P.;Schmidt, D.;Schmidt, J.;Schubert, M. A.;Schulz, K.;Tillack, B.;Wolansky, |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1678 - 1686 |
| Publisher: IEEE |
| Full litterature document |
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| » A 1.3-GHz 350-mW Hybrid Direct Digital Frequency Synthesizer in 90-nm CMOS |
Abstract:
This paper presents a low-power direct digital frequency synthesizer (DDFS) based on a hybrid design with a maximum operating frequency of 1.3 GHz. The proposed hybrid design is capable of extending the resolution of traditional nonlinear digital-to-analog converter (DAC)-based DDFS by adding a linear slope component to the approximated sine wave produced from a nonlinear DAC via an additional linear DAC. With an 11-bit combined DAC, the prototype DDFS produces a minimum spurious free dynamic range (SFDR) of 52 dBc from dc up to Nyquist frequency when clocked at 1.3 GHz. This 90-nm CMOS chip occupies 2 ${hbox {mm}}^{2}$ including bond pads and dissipates 350 mW with a 1.2-V digital supply and 2.5-V analog supply. The FOM of this chip is measured at 1207.9 $hbox{GHz} cdot 2 ^{rm ENOB} /hbox{W}$ . |
| Autors: Yeoh, H. C.;Jung, J.-H.;Jung, Y.-H.;Baek, K.-H.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1845 - 1855 |
| Publisher: IEEE |
| Full litterature document |
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| » A 25 MHz Bandwidth 5th-Order Continuous-Time Low-Pass Sigma-Delta Modulator With 67.7 dB SNDR Using Time-Domain Quantization and Feedback |
Abstract:
This paper introduces a continuous-time low-pass sigma-delta modulator operating with a seven-phase 400$,$ MHz clocking scheme to control time-based processing in the 3-bit two-step quantizer and main digital-to-analog converter (DAC). An on-chip voltage-controlled oscillator and a complementary injection-locked frequency divider are utilized for low-jitter clock signal generation with multiple phases, allowing 3-bit pulse-width modulated feedback with a single-element DAC to avoid performance degradation from unit element mismatch problems associated with conventional multi-bit DACs. |
| Autors: Lu, C.-Y.;Onabajo, M.;Gadde, V.;Lo, Y.-C.;Chen, H.-P.;Periasamy, V.;Silva-Martinez, J.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1795 - 1808 |
| Publisher: IEEE |
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» A 6-  W Chip-Area-Efficient Output-Capacitorless LDO in 90-nm CMOS Technology |
Abstract:
An output-capacitorless low-dropout regulator (LDO) compensated by a single Miller capacitor is implemented in a commercial 90-nm CMOS technology. The proposed LDO makes use of the small transistors realized in nano-scale technology to achieve high stability, fast transient performance and small voltage spikes under rapid load-current changes without the need of an off-chip capacitor connected at the LDO output. Experimental result verifies that the proposed LDO is stable for a capacitive load from 0 to 50 pF (estimated equivalent parasitic capacitance from load circuits) and with load capability of 100 mA. Moreover, the gain-enhanced structure provides sufficient loop gain to improve line regulation to 3.78 mV/V and load regulation to 0.1 mV/mA, respectively. The embedded voltage-spike detection circuit enables pseudo Class-AB operation to drive the embedded power transistor promptly. The measured power consumption is only 6 $mu$W under a 0.75-V supply. The maximum overshoot and undershoot under a 1.2-V supply are less than 66 mV for full load current changes within 100-ns edge time, and the recovery time is less than 5 $mu$s. |
| Autors: Guo, J.;Leung, K. N.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1896 - 1905 |
| Publisher: IEEE |
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| » A 60 GHz Phase Shifter Integrated With LNA and PA in 65 nm CMOS for Phased Array Systems |
Abstract:
This paper presents the design of a 60 GHz phase shifter integrated with a low-noise amplifier (LNA) and power amplifier (PA) in a 65 nm CMOS technology for phased array systems. The 4-bit digitally controlled RF phase shifter is based on programmable weighted combinations of I/Q paths using digitally controlled variable gain amplifiers (VGAs). With the combination of an LNA, a phase shifter and part of a combiner, each receiver path achieves 7.2 dB noise figure, a 360$^{circ}$ phase shift range in steps of approximately 22.5 $^{circ}$, an average insertion gain of 12$~$dB at 61$~$GHz, a 3 dB-bandwidth of 5.5 GHz and dissipates 78 mW. Consisting of a phase shifter and a PA, one transmitter path achieves a maximum output power of higher than $+$8.3 dBm, a 360$^{circ}$ phase shift range in 22.5$^{circ}$ steps, an average insertion gain of 7.7 dB at 62 GHz, a 3 dB-bandwidth of 6.5 GHz and dissipates 168 mW. |
| Autors: Yu, Y.;Baltus, P. G. M.;de Graauw, A.;van der Heijden, E.;Vaucher, C. S.;van Roermund, A. H. M.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1697 - 1709 |
| Publisher: IEEE |
| Full litterature document |
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| » A 60-GHz OOK Receiver With an On-Chip Antenna in 90 nm CMOS |
Abstract:
A low power 60-GHz on-off-keying (OOK) receiver has been implemented in a commercial 90 nm RF CMOS process. By employing a novel on-chip antenna together with architecture optimization, the receiver achieves a sensitivity of ${-}$47 dBm at a bit-error rate (BER) of less than 10 $^{-3}$. Using a commercial transmitter with transmit power of 1.5 dBm, a transmission distance of 5 cm can be achieved at 1.2 Gbps data rate. In this design, the on-chip antenna minimizes the packaging loss, while energy detection at RF allows architecture simplification. Both techniques contribute to the receiver's low power consumption of 51 mW, excluding test buffers. This leads to a bit energy efficiency of 28 pj/bit at 1.8 Gbps. The total die area is 3.8 mm$^{2}$ with the on-chip antenna occupying almost half of it. |
| Autors: Kang, K.;Lin, F.;Pham, D.-D.;Brinkhoff, J.;Heng, C.-H.;Guo, Y. X.;Yuan, X.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1720 - 1731 |
| Publisher: IEEE |
| Full litterature document |
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| » A 64 Channel Programmable Closed-Loop Neurostimulator With 8 Channel Neural Amplifier and Logarithmic ADC |
Abstract:
This paper describes a neurostimulation IC for use in advanced closed-loop neurostimulation applications, such as deep brain stimulation (DBS) for treatment and research of neurological disorders including Parkinson's disease. This system senses and filters neural activity with eight pre-amplifiers, a 200 kS/s 8-bit log ADC and digital filters and incorporates 64 programmable current-stimulation channels. The entire device, implemented in 0.18 $mu{hbox {m}}$ CMOS, occupies 2.7 ${hbox {mm}}^{2}$ and consumes 89 $mu{hbox {W}}$ in normal operation mode and 271 $mu{hbox {W}}$ in configuration mode from a 1.8 V supply. |
| Autors: Lee, J.;Rhew, H.-G.;Kipke, D. R.;Flynn, M. P.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1935 - 1945 |
| Publisher: IEEE |
| Full litterature document |
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» A 9-bit, 14 μW and 0.06 mm  Pulse Position Modulation ADC in 90 nm Digital CMOS |
Abstract:
This work presents a compact, low-power, time-based architecture for nanometer-scale CMOS analog-to-digital conversion. A pulse position modulation ADC architecture is proposed and a prototype 9 bit PPM ADC incorporating a two-step TDC scheme is presented as proof of concept. The 0.06 ${hbox {mm}}^{2}$ prototype is implemented in 90 nm CMOS and achieves 7.9 effective bits across the entire input bandwidth and dissipates 14 $mu{hbox {W}}$ at 1 MS/s. |
| Autors: Naraghi, S.;Courcy, M.;Flynn, M. P.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1870 - 1880 |
| Publisher: IEEE |
| Full litterature document |
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| » A $Q$-Modification Neuroadaptive Control Architecture for Discrete-Time Systems |
Abstract:
This brief extends the new neuroadaptive control framework for continuous-time nonlinear uncertain dynamical systems based on a $Q$ -modification architecture to discrete-time systems. As in the continuous-time case, the discrete-time update laws involve auxiliary terms, or $Q$-modification terms, predicated on an estimate of the unknown neural network weights which in turn involve a set of auxiliary equations characterizing a set of affine hyperplanes. In addition, we show that the $Q$ -modification terms in the discrete-time update law are designed to minimize an error criterion involving a sum of squares of the distances between the update weights and the family of affine hyperplanes. |
| Autors: Volyanskyy, K. Y.;Haddad, W. M.; |
| Appeared in: IEEE Transactions on Neural Networks |
| Publication date: Sep 2010, volume: 21, issue:9, pages: 1507 - 1511 |
| Publisher: IEEE |
| Full litterature document |
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| » A Bayesian Framework for Image Segmentation With Spatially Varying Mixtures |
Abstract:
A new Bayesian model is proposed for image segmentation based upon Gaussian mixture models (GMM) with spatial smoothness constraints. This model exploits the Dirichlet compound multinomial (DCM) probability density to model the mixing proportions (i.e., the probabilities of class labels) and a Gauss–Markov random field (MRF) on the Dirichlet parameters to impose smoothness. The main advantages of this model are two. First, it explicitly models the mixing proportions as probability vectors and simultaneously imposes spatial smoothness. Second, it results in closed form parameter updates using a maximum a posteriori (MAP) expectation-maximization (EM) algorithm. Previous efforts on this problem used models that did not model the mixing proportions explicitly as probability vectors or could not be solved exactly requiring either time consuming Markov Chain Monte Carlo (MCMC) or inexact variational approximation methods. Numerical experiments are presented that demonstrate the superiority of the proposed model for image segmentation compared to other GMM-based approaches. The model is also successfully compared to state of the art image segmentation methods in clustering both natural images and images degraded by noise. |
| Autors: Nikou, C.;Likas, A.;Galatsanos, N.; |
| Appeared in: IEEE Transactions on Image Processing |
| Publication date: Sep 2010, volume: 19, issue:9, pages: 2278 - 2289 |
| Publisher: IEEE |
| Full litterature document |
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| » A Bubble-activated Micropump with High-frequency Flow Reversal |
Abstract:
With the increasing demand for thermal management in electronic cooling applications, the development of heat dissipation devices has become extremely important. This paper presents the development of a novel bubble-activated micropump with high-frequency flow reversal using embedded electrodes in a closed fluidic microchannel. This bubble-activated micropump consists of a microfluidic chamber structure and microelectrodes on a glass substrate that is assembled using a polydimethylsiloxane (PDMS) elastic sheet. First, the bubble-activated micropump was fabricated on a silicon substrate by spin-coating, curing, and molding using negative photoresist SU-8 2035 as the mold material. Second, a phosphate buffer solution (PBS) was introduced into... |
| Autors: Shih-Chi, Chan , Chia-Ray, Chen , Cheng-Hsien, Liu |
| Appeared in: Sensors and Actuators A: Physical |
| Publication date: Sep 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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| » A co-operative beamforming solution for eliminating multi-hop communications in wireless sensor networks |
Abstract:
This paper proposes a new system architecture for continuous monitoring wireless sensor networks, utilizing recent developments in the areas of cooperative beam-forming, radio frequency integrated circuit technology, and spread-spectrum techniques. In the proposed system, nodes are activated only when they are triggered to send their own data to the fusion center directly, without burdening the network with MAC layer collisions and energy-consuming routing algorithms, thus guaranteeing long lifetime cycles. The nodes consist of a simple active reflector circuit which is synchronized by an incident wave transmitted by a distant base station. Since the nodes can be deployed in large numbers, the network acts as a single antenna array with high directive gain pointing towards the direction of the fusion center. At the receiver, data from each node can be de-multiplexed with the use of a frequency shift keying direct sequence spread spectrum modulation scheme that enables multiple access without destroying the beamforming characteristics of the network. |
| Autors: Kalis, A.;Kanatas, A.G.;Efthymoglou, G.P.; |
| Appeared in: IEEE Journal on Selected Areas in Communications |
| Publication date: Sep 2010, volume: 28, issue:7, pages: 1055 - 1062 |
| Publisher: IEEE |
| Full litterature document |
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| » A Collaborative Recommender System Based on Space-Time Similarities |
Abstract:
The Internet of Things (IoT) concept promises a world of networked and interconnected devices that provides relevant content to users. Recommender systems can find relevant content for users in IoT environments, offering a user-adapted personalized experience. Collaboration-based recommenders in IoT environments rely on user-to-object, space-time interaction patterns. This extension of that idea takes into account user location and interaction time to recommend scattered, pervasive context-embedded networked objects. The authors compare their proposed system to memory-based collaborative methods in which user similarity is based on the ratings of previously rated items. Their proof-of-concept implementation was used in a real-world scenario involving 15 students interacting with 75 objects at Carlos III University of Madrid. |
| Autors: Munoz-Organero, M.;Ramíez-González, G.A.;Munoz-Merino, P.J.;Delgado Kloos, C.; |
| Appeared in: IEEE Pervasive Computing |
| Publication date: Sep 2010, volume: 9, issue:3, pages: 81 - 87 |
| Publisher: IEEE |
| Full litterature document |
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| » A Comparison of Flux Variance and Surface Renewal Methods With Eddy Covariance |
Abstract:
Sensible and latent heat fluxes are important parameters for understanding energy/mass interactions. At present, there are a number of methods available to estimate these fluxes, with varying degrees of difficulty and success. In the present study, we explore the use of the flux variance method and the surface renewal method to estimate the sensible and latent heat fluxes in two agricultural sites in China. The results of these two methods were compared to direct measurements using eddy covariance. The study sites, a wheat field in a semi-arid area and a rice paddy in a humid area provide an opportunity to examine two extreme conditions. In the arid conditions, both estimation methods provided similar sensible heat flux estimations but higher latent heat flux estimations with respect to the eddy covariance measurements. The sum of the estimated sensible and latent heat fluxes was in good agreement with measurements. In the rice paddy, sensible heat flux estimated by both methods showed similar results, whereas latent heat fluxes estimation were 1.2 times greater than eddy covariance measurements. The surface renewal method underestimated the Bowen ratio over the rice paddy, but overestimated it over the wheat field. In conclusion, both methods appear more appropriate for the estimation of sensible heat flux rather than for latent heat flux, in particular in humid environments. |
| Autors: Zhao, X.;Liu, Y.;Tanaka, H.;Hiyama, T.; |
| Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Publication date: Sep 2010, volume: 3, issue:3, pages: 345 - 350 |
| Publisher: IEEE |
| Full litterature document |
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| » A Delay-Based Multicast Overlay Scheme for WDM Passive Optical Networks With 10-Gb/s Symmetric Two-Way Traffics |
Abstract:
We propose a delay-based multicast overlay scheme to superimpose a multicast differential phase-shift keying (DPSK) modulated signal on a point-to-point downstream inverse-return-to-zero (IRZ) modulated signal in a wavelength-division-multiplexed passive optical network (WDM-PON). By adjusting the synchronization of the DPSK and the IRZ modulation on the downstream carrier, simple and flexible multicast control could be realized. We have successfully demonstrated the proposed scheme for three different traffics, namely 10-Gb/s IRZ downstream point-to-point data, 10-Gb/s DPSK downstream multicast data, and 10-Gb/s non-return-to-zero (NRZ) upstream re-modulated data, respectively. An error floor of $10^{-4}$ is observed for the multicast data when it is disabled. The effect of timing misalignment on the downstream DPSK/IRZ orthogonal modulation and the upstream re-modulation is analyzed. We also study the case when the data rates of the multicast and downstream point-to-point data are different. |
| Autors: Xu, J.;Zhang, Y.;Chen, L.-K.;Chan, C.-K.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2660 - 2666 |
| Publisher: IEEE |
| Full litterature document |
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| » A distributed and energy-efficient framework for Neyman-Pearson detection of fluctuating signals in large-scale sensor networks |
Abstract:
To address the challenges inherent to a problem of practical interest - of Neyman-Pearson detection of fluctuating radar signals using wireless sensor networks, we propose in this paper a distributed and energy-efficient framework. Such framework is scalable with respect to the network size, and is able to greatly reduce the dependence on the central fusion center. It assumes a clustering infrastructure, and addresses signal processing and communications related issues arising from different layers. This framework includes a distributed scheduling protocol and a distributed routing protocol, which enable sensor nodes to make their own decisions about information transmissions, without requiring the knowledge of the network global information. In this framework, energy efficiency manifests itself at different network layers in a distributed fashion, and a balance between the detection performance and the energy efficiency is also attained. |
| Autors: Yang, Y.;Blum, R.S.;Sadler, B.M.; |
| Appeared in: IEEE Journal on Selected Areas in Communications |
| Publication date: Sep 2010, volume: 28, issue:7, pages: 1149 - 1158 |
| Publisher: IEEE |
| Full litterature document |
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| » A Doppler Robust Max-Min Approach to Radar Code Design |
Abstract:
This correspondence considers the problem of robust waveform design in the presence of colored Gaussian disturbance under a similarity and an energy constraint. We resort to a max-min approach, where the worst case detection performance (over the possible Doppler shifts) is optimized with respect to the radar waveform under the previously mentioned constraints. The resulting optimization problem is a non-convex Quadratically Constrained Quadratic Program (QCQP) with an infinite number of constraints, which is NP-hard in general and typically difficult to solve. Hence, we propose an algorithm with a polynomial computational complexity to generate a good sub-optimal solution for the aforementioned QCQP. The analysis, conducted in comparison with some known radar waveforms, shows that the sub-optimal solutions by the algorithm lead to high-quality radar signals. |
| Autors: De Maio, A.;Huang, Y.;Piezzo, M.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Sep 2010, volume: 58, issue:9, pages: 4943 - 4947 |
| Publisher: IEEE |
| Full litterature document |
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| » A Fast Four-Point Sense Methodology for Extraction of Circuit-Relevant Degradation Parameters |
Abstract:
A fast measurement methodology to extract, in a single stress sequence, four different circuit-relevant degradation parameters is introduced. The methodology is used to compare the degradation of the linear and saturation drain currents, as well as the linear and saturation threshold voltages, during positive bias temperature instability (BTI) (PBTI) in metal-gate/high-$k$ (MG/HK) nFETs and during negative BTI (NBTI) in conventional poly-Si/SiON pFET devices. No $g_{m}$ degradation is observed for PBTI in MG/HK nFET devices, whereas $g_{m}$ degradation is evident for NBTI in conventional poly-Si/SiON pFETs. Furthermore, the impact of measurement delay on parameter correlation is investigated, leading to important conclusions regarding the physical origin of $g_{m}$ degradation during BTI stress. |
| Autors: Kerber, A.;Cartier, E.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 912 - 914 |
| Publisher: IEEE |
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| » A Fast-Converging Equalizer for Upstream DOCSIS Channels |
Abstract:
This paper proposes a method of increasing the efficiency of the CATV plant in the upstream direction. The general approach is to reduce the convergence time of the equalizer to allow a shorter training sequence. Specifically, the upstream channel is modeled as a postdetection filter. A short unique word is inserted near the beginning of the preamble to estimate the coefficients of the postdetection filter. The postdetection filter is then crudely inverted to estimate a few key tap weights of the equalizer. The equalizer is initialized with these estimated tap weights before adaptive updating is turned on. The method is evaluated for the echo-laden DOCSIS CATV upstream channel with a signal-to-noise ratio (SNR) of 25 dB. Plots of the probability of the modulation error ratio exceeding 19- and 22-dB values versus the length of the training sequence show that the performance is comparable to an unseeded equalizer with a training sequence that is about 50 symbols longer. |
| Autors: Andalibi, Z.;Berscheid, B.;Salt, J. E.;Nguyen, H. H.; |
| Appeared in: IEEE Transactions on Broadcasting |
| Publication date: Sep 2010, volume: 56, issue:3, pages: 311 - 320 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Field Platform for Continuous Measurement of Canopy Fluorescence |
Abstract:
This paper presents a field platform for continuous measurement of fluorescence at the canopy level. It consists of a 21-m-high crane equipped for fluorescence measurements. The crane is installed in the middle of the fields dedicated to agricultural research. Thanks to a jib of 24 m and a railway of 100 m distance, fluorescence measurements can be performed at nadir viewing over various field crops. The platform is dedicated to the development and test of future passive or active airborne and space-borne vegetation sensors. A new fully automatic instrument, called TriFLEX, has been installed at the end of the jib. TriFLEX is designed for passive measurement of fluorescence in the oxygen A and B absorption bands. It is based on three spectrometers and allows for continuous measurements with a repetition rate of about 1 Hz. The data products are the radiances of the target, the fluorescence flux at 687 and 760 nm, and several vegetation indexes, including the photochemical reflectance index and the normalized difference vegetation index. A new algorithm for fluorescence retrieval from spectral bands measurement is described. It improves upon the well-known Fraunhofer line discriminator method applied to passive fluorescence measurement by taking into account the spectral shape of fluorescence and the reflectance of vegetation. A measurement campaign of 38 days has been carried out in summer 2008 over a sorghum field. The evolution of the signals showed that the crop was suffering from stress due to lack of water. After several rainy days, a reversion of the water stress was observed. |
| Autors: Daumard, F.;Champagne, S.;Fournier, A.;Goulas, Y.;Ounis, A.;Hanocq, J.-F.;Moya, I.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Sep 2010, volume: 48, issue:9, pages: 3358 - 3368 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Floating-Gate-Based Field-Programmable Analog Array |
Abstract:
A field-programmable analog array (FPAA) with 32 computational analog blocks (CABs) and occupying 3 $, times,$3 $~$mm$^2$ in 0.35-$mu$m CMOS is presented. Each CAB has a wide variety of subcircuits ranging in granularity from multipliers and programmable offset wide-linear-range Gm blocks to nMOS and pMOS transistors. The programmable interconnects and circuit elements in the CAB are implemented using floating-gate (FG) transistors, the total number of which exceeds fifty thousand. Using FG devices eliminates the need for SRAM to store configuration bits since the switch stores its own configuration. This system exhibits significant performance enhancements over its predecessor in terms of achievable dynamic range (${>}, $9 b of FG voltage) and speed (${approx}, $20 gates/s) of accurate FG current programming and isolation between on and off switches. An improved routing fabric has been designed that includes nearest neighbor connections to minimize the penalty on bandwidth due to routing parasitic. A maximum bandwidth of 57 MHz through the switch matrix and around 5 MHz for a first-order low-pass filter is achievable on this chip, the limitation being a “program” mode switch that will be rectified in the next chip. Programming performance improved drastically by implementing the entire algorithm on-chip with an SPI digital interface. Measured results of the individual subcircuits and two system examples including an AM receiver and a speech processor are presented. |
| Autors: Basu, A.;Brink, S.;Schlottmann, C.;Ramakrishnan, S.;Petre, C.;Koziol, S.;Baskaya, F.;Twigg, C. M.;Hasler, P.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1781 - 1794 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Framework for Low Complexity Least-Squares Localization With High Accuracy |
Abstract:
In this paper, a new framework is proposed for least-squares localization based on estimated ranges, covering time-difference-of-arrival (TDoA), time-of-arrival (ToA), and received signal strength (RSS) cases. The multidimensional nonlinear localization problem is first transformed to a lower dimension and then solved iteratively. Within the proposed transformed least-squares (TLS) framework, we introduce a method in which the localization problem is transformed to one dimension (1-D). In this way, compared to the classical nonlinear least-squares (NLS) type of methods, the amount of computations in each iteration is greatly reduced; a reduction of 67% for a 3-D positioning system is shown. Hence, the introduced 1-D iterative (1DI) method is fairly light on the computational load. The way to choose the 1-D parameter is proposed, and theoretical expressions for the convergence rate and the root- mean-squared error (RMSE) of the 1DI estimator are derived. Validation is performed mainly based on actual ultra-wideband (UWB) radio measurements, collected in typical office environments, with signal bandwidths varying from 0.5 to 7.5 GHz. Supplementary simulations are also included for validation. Results show that, in terms of RMSE, the 1DI method performs better than the linear least-squares (LLS) method, where the solution is obtained noniteratively, and performs similarly as NLS, especially in TDoA cases. |
| Autors: Yan, J.;Tiberius, C. C. J. M.;Teunissen, P. J. G.;Bellusci, G.;Janssen, G. J. M.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Sep 2010, volume: 58, issue:9, pages: 4836 - 4847 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Fully Analytic Model of Large Area Silicon p-i-n Photodiodes Verified at Short Wavelengths |
Abstract:
A fully analytic analysis of the frequency response of a homo-structure p-i-n photodiode is developed to characterize high-speed large-area p-i-n photodiodes. Therefore, the model can easily be implemented in mathematical simulation tools for system analysis. The model accurately describes drift-, diffusion- and parasitic effects and has been experimentally verified up to 3 GHz for a variety of different wavelength from 405 nm to 850 nm far beyond the 3 dB cutoff frequency (up to ${-}$ 35 dB). |
| Autors: Loquai, S.;Bunge, C.-A.;Ziemann, O.;Schmauss, B.;Kruglov, R.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2646 - 2653 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Fully Integrated Built-In Self-Test  ADC Based on the Modified Controlled Sine-Wave Fitting Procedure |
Abstract:
This paper demonstrates the first fully integrated built-in self-test (BIST) $Sigma{-}Delta$ analog-to-digital converter (ADC) chip to the best of our knowledge. The ADC under test (AUT) comprises a second-order design-for-digital-testability $ Sigma{-}Delta$ modulator and a decimation filter. The purely digital BIST circuitry conducts single-tone tests for the signal-to-noise-and-distortion ratio (SNDR), the dynamic range, the offset, and the gain error of the AUT. The BIST design is based on the proposed modified controlled sine-wave fitting procedure to address the component overload issues, reduce the setup parameter numbers, and eliminate the need for parallel multipliers. The total gate count of the whole BIST circuitry is only 13 300. The hardware overhead is much less than the BIST design using the traditional fast Fourier transform (FFT) analysis. Measurement results show that the peak SNDR results of the proposed BIST design and the conventional FFT analysis are 75.5 and 75.3 dB, respectively. The subtle SNDR difference is already within analog test uncertainty. The BIST $Sigma{-}Delta$ ADC achieves a digital test bandwidth higher than 17 kHz, very close to the rated 20-kHz bandwidth of the AUT. |
| Autors: Hong, H.-C.;Su, F.-Y.;Hung, S.-F.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Sep 2010, volume: 59, issue:9, pages: 2334 - 2344 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Fuse-Blow Scheme |
Abstract:
A fuse-blow philosophy has been adopted by some utilities in an effort to decrease the number of momentary average interruption frequency index (MAIFI) seen by their customers. This practice has the inherent drawback that, by converting a temporary fault (e.g., lightning and animals) into a sustained interruption, they are in effect decreasing the reliability of their system [i.e., system average interruption duration index (SAIDI) will increase]. This article addresses the impact of a fuse-blow philosophy on long lines commonly found in rural electric utilities as well as shorter lines that are ubiquitous in more urban areas. It also assesses the differences in the impact of these schemes in terms of both power quality (momentaries) and reliability issues. Detailed analysis of the impact on the utility system is presented and discussed. |
| Autors: O'Meally, C.A.;Burke, J.; |
| Appeared in: IEEE Industry Applications Magazine |
| Publication date: Sep 2010, volume: 16, issue:5, pages: 37 - 42 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A General Characterization for Polarimetric Scattering From Vegetation Canopies |
Abstract:
Current polarimetric model-based decomposition techniques are limited to specific types of vegetation because of their assumptions about the volume scattering component. In this paper, we propose a generalized probability density function based on the $n$th power of a cosine-squared function. This distribution is completely characterized by two parameters; a mean orientation angle and the power of the cosine-squared function. We show that the underlying randomness of the distribution is only a function of the power of the cosine-squared function. We then derive the average covariance matrix for various different elementary scatterers showing that the result has a very simple analytical form suitable for use in model-based decomposition schemes. |
| Autors: Arii, M.;van Zyl, J. J.;Kim, Y.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Sep 2010, volume: 48, issue:9, pages: 3349 - 3357 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Generalized Half-Wave Symmetry SHE-PWM Formulation for Multilevel Voltage Inverters |
Abstract:
Half-cycle symmetry selective-harmonic-elimination pulsewidth-modulation (SHE-PWM) problems may have a large number of valid solutions, which are beneficial to the optimization design. This paper proposes a novel generalized formulation of half-cycle symmetry SHE-PWM problems for multilevel inverters. The advantages of the proposed formulation include simplicity in format, flexibility in PWM waveforms, and a broad solution space. A method to obtain initial values for the SHE-PWM equations according to the reference modulation index $M$ and the initial phase angle of output fundamental voltage is proposed and investigated thoroughly. Take a five-level inverter with $M = 0.75$ as an example; six sets of solutions for two typical initial phase angles of 0 $^{circ}$ and 90$^{circ}$ are presented. Simulations and experiments are carried out. It is demonstrated that the experimental results agree well with simulated ones, which proves the validity and practicability of the new method proposed. |
| Autors: Fei, W.;Du, X.;Wu, B.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 3030 - 3038 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Generic Scalable Architecture for Min-Sum/Offset-Min-Sum Unit for Irregular/Regular LDPC Decoder |
Abstract:
The most common algorithm used in iterative decoding of low-density parity check (LDPC) codes is based on a generic class of the sum-product algorithm, which has a nonlinear dependence on the log(tanh()) function. The implementation based on fixed precision has substantial loss of accuracy and is computationally expensive with full precision. A suboptimal version of belief propagation called the offset-min-sum algorithm is generally used in hardware implementation. This paper proposes a generic scalable architecture for minimum search during check-node operation in the offset-min-sum algorithm applicable to regular as well as irregular LDPC codes with check node of any degree ${d}$. For an LDPC code with maximum check node degree ${d}$ , the proposed architecture consists of $2(d-2)$ 2 $, times ,$1 multiplexers and $3(d-2)$ two-input compare-and-select units (CSUs). This has latency of $[{2}lceil log _{2}(d)rceil -2]t_{dc}$ when $lceil log _{2}(d)rceil -log _{2}(d) < log _{2}({4}/{3})$ else $[{2}lceil log _{2}(d)rceil -3]t_{dc}$, with $t_{dc}$ representing the delay of a two-input CSU. The proposed architecture has been implemented for ${d=20}$ using a TSMC 0.18-$mu hbox {m}$ CMOS process. |
| Autors: Srinivasan, V. K. K.;Singh, C. K.;Balsara, P. T.; |
| Appeared in: IEEE Transactions on Very Large Scale Integration Systems |
| Publication date: Sep 2010, volume: 18, issue:9, pages: 1372 - 1376 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A High-Speed Current-Mode Data Driver With Push-Pull Transient Current Feedforward for Full-HD AMOLED Displays |
Abstract:
A push-pull transient current feedforward driver is designed to have a complete push-pull function and loop gain control that enhances the data current drivability. The sink and source current capability of the proposed driver makes it insensitive to the initial voltage levels on the data lines and provides a reduced settling time. The gain control in the positive feedback loop offers a fast settling time without ringing over the complete range of pixel drive currents. The data driver exhibits a settling time of better than 6 $mu{hbox {s}}$ for drive currents from 20 nA to 5 $mu hbox{A}$ into an equivalent full-HD AMOLED display panel parasitic load of 4 $hbox{k}Omega$ series resistance and 90 pF shunt capacitance. The driver consumes a static current of 4.5 $mu hbox{A/channel}$. |
| Autors: Jeon, Y.-J.;Jeon, J.-Y.;Son, Y.-S.;Huh, J.;Cho, G.-H.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1881 - 1895 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A High-Speed Low-Power Multi-VDD CMOS/SIMOX SRAM With LV-TTL Level Input/Output Pins—Write/Read Assist Techniques for 1-V Operated Memory Cells |
Abstract:
The use of multiple power supplies with different output voltages has a great advantage in that it makes it possible to realize high performance ULSIs with low power dissipation. This paper presents a high-speed low-power SRAM that employs three power supplies (1, 2, and 3.3 V). A 1-V power supply is mainly used in the SRAM core to save standby and/or active power, while a 2-V supply is used in critical components to realize high performance. The voltage applicable to each MOSFET is up to 2.2 V because of the use of a 5-nm ultrathin gate oxide, and so the 3.3-V power supply is used only for LV-TTL level I/O buffers. Secure write operation for 1-V six-transistor memory cells is guaranteed by using a new switched powerline impedance scheme. To reduce dynamic write power dissipation, a segmented bitline scheme is adopted and long global bitlines are assigned to the 4th (topmost) metal layer. The data stored in memory cells are read out via virtual-GND lines by sensing the change in current volume. The practical use of parasitic bipolar action in SOI MOSFETs is being actively considered as a way of obtaining a large read current from memory cells. In addition, a 1-V double-rail bidirectional intradatabus is developed for transferring multibit high-speed data between the SRAM core and I/O buffers. A 32K-word$,{times},$ 9-bit SRAM chip, fabricated with the 0.2- $mu$m-gate CMOS/SIMOX process, has achieved a 7.5-ns address access time for 65-pF external loads. The power dissipation during standby is less than 0.3 mW and the values for 100-MHz operation are 5.8$~$mW (write) and 11.0 mW (read), excluding that of the 3.3-V I/O buffers. |
| Autors: Shibata, N.;Watanabe, M.;Okiyama, H.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1856 - 1869 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A highly linear receiver front-end employing modified derivative superposition method with tuned inductors for 5.25GHz |
Abstract:
We design a highly linear CMOS RF receiver front-end operating in the 5GHz band using the modified derivative superposition (DS) method with one- or two-tuned inductors in the low noise amplifier (LNA) and mixer. This method can be used to adjust the magnitude and phase of the third-order currents at output, and thus ensure that they cancel each other out. We characterize the two front-ends by the third-order input intercept point (IIP3), voltage conversion gain, and a noise figure based on the TSMC 0.18?m RF CMOS process. Our simulation results suggest that the front-end with one-tuned inductor in the mixer... |
| Autors: Youngbin, Ahn , Chiwan, Park , Jaehoon, Lee , Jichai, Jeong |
| Appeared in: Microelectronics Journal |
| Publication date: Sep 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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|
| » A Holistic Approach to the Integration of Safety Applications: The INSAFES Subproject Within the European Framework Programme 6 Integrating Project PReVENT |
Abstract:
This paper deals with the integration of multiple advanced driver-assistance systems (ADAS) and in-vehicle information systems (IVIS) in a holistic driver-support system. The paper presents the results of a project named Integrated Safety Systems (INSAFES), which was part of PReVENT: an integrating project carried out under the European Framework Programme 6. Integration in INSAFES is tackled at three different levels in the framework of a “cognitive car” perspective: 1) at the perception level, to represent the world around the vehicle, including object-tracking between sensor fields and the detection of driver intentions; 2) at the decision level, to reproduce humanlike holistic motion plans, which serve as “reference maneuvers” to evaluate the motion alternatives that a driver faces; and 3) at the level of interaction with the driver and vehicle control ( action level), to arbitrate between the requests of functions competing for driver attention. A function that provides simultaneous longitudinal and lateral support has been developed. It gives support for safe speed, safe distance, lane change, and all-around collision avoidance all at the same time. At its core, there is a tool (evasive/reference maneuver) that constantly evaluates two possible alternatives (in lane and evasive/lane change) and compares them with the driver input to detect which one applies, which dictates warnings and driver interactions, and whether there is a better alternative. In addition, a “warning manager” has been developed, acting like a referee who lets the ADAS applications work standalone and then combines the requests of each application, prioritizes them, and manages the interaction with the user. The warning manager can be particularly useful in the case of integration of pre-existing standalone functions, which can be quickly reused. If a holistic ADAS is developed, the warning manager can still be used to combine it with IVIS fu-
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nctions. In fact, depending on the kind of ADAS and IVIS considered, the most suitable approach can be either to combine functions in a unified multifunctional driver-support application or to arbitrate between them through the warning manager. |
| Autors: Amditis, A.;Bertolazzi, E.;Bimpas, M.;Biral, F.;Bosetti, P.;Da Lio, M.;Danielsson, L.;Gallione, A.;Lind, H.;Saroldi, A.;Sjogren, A.; |
| Appeared in: IEEE Transactions on Intelligent Transportation Systems |
| Publication date: Sep 2010, volume: 11, issue:3, pages: 554 - 566 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Knowledge-Based Approach to Online Fault Diagnosis of FET Biosensors |
Abstract:
Real-time diagnosis of insulator–semiconductor field-effect transistor (ISFET)-based biosensor systems aims at promptly correcting errors caused by insufficient function; insufficiency is judged by the operational behavior of the sensor, i.e., the data that it produces. Ultimately, a complete failure of the system (i.e., a “dead” sensor) should easily be recognized. Much more difficult is the recognition of a gradual malfunction of this complex system, which may be attributed to faults or failures in one or more of its subsystems. Evidently, the identification of the possible fault modes and their symptoms requires in-depth knowledge of sensor's design and operation, both from the biochemical and electrical/electronic points of view, along with tackling uncertain, incomplete, or imprecise information. In this paper, a novel real-time diagnostic expert scheme for field-effect transistor (FET)-based biosensing is proposed. This paper 1) investigates the causes of sensor misfunction by means of fault tree analysis (FTA) relying on fuzzy reasoning to account for uncertainty and 2) proposes a computer-aided method for diagnosing biosensor failure during operation through an algorithmic procedure that is based on a nested loop mechanism. The tree (dendritic) structure (built using the information provided by the biosensor components and their intrarelations/interrelations on a surface- and a deep-knowledge level) serves as the knowledge base (KB), and the fuzzy-rules-based decision mechanism is the inference engine for fault detection and isolation. |
| Autors: Siontorou, C. G.;Batzias, F. A.;Tsakiri, V.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Sep 2010, volume: 59, issue:9, pages: 2345 - 2364 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A little feedback can simplify sensor network cooperation |
Abstract:
Shannon's discovery of digital communication has shaped the architecture of virtually all communication systems in use today. The digital communication paradigm is built around the notion of bits and uses careful coding to deliver bits reliably end-to-end. It has been shown that this architectural principle can lead to a very significant performance penalty in wireless sensor networks. For a limited class of network scenarios, it was shown that optimal architectures are analog in nature, simple and scalable. In this paper, we show that more generally, simple analog architectures crucially depend on feedback to the sensors. Interesting questions then concern the amount of feedback needed and the resulting trade-off with performance. This paper provides rules-of-thumb for the selection of the number of feedback bits. |
| Autors: Sarwate, A.;Gastpar, M.; |
| Appeared in: IEEE Journal on Selected Areas in Communications |
| Publication date: Sep 2010, volume: 28, issue:7, pages: 1159 - 1168 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low Complexity Blind Estimator of Narrowband Polynomial Phase Signals |
Abstract:
Consider the problem of estimating the parameters of multiple polynomial phase signals observed by a sensor array. In practice, it is difficult to maintain a precisely calibrated array. The array manifold is then assumed to be unknown, and the estimation is referred to as blind estimation. To date, only an approximated maximum likelihood estimator (AMLE) was suggested for blindly estimating the polynomial coefficients of each signal. However, this estimator requires a multidimensional search over the entire coefficient space. Instead, we propose an estimation approach which is based on two steps. First, the signals are separated using a blind source separation technique, which exploits the constant modulus property of the signals. Then, the coefficients of each polynomial are estimated using a least squares method applied to the unwrapped phase of the estimated signal. This estimator does not involve any search in the coefficient spaces. The computational complexity of the proposed estimator increases linearly with respect to the polynomial order, whereas that of the AMLE increases exponentially. Simulation results show that the proposed estimator achieves the Cramér-Rao lower bound at moderate or high signal to noise ratio. |
| Autors: Amar, A.;Leshem, A.;van der Veen, A.-J.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Sep 2010, volume: 58, issue:9, pages: 4674 - 4683 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low False Negative Filter for Detecting Rare Bird Species From Short Video Segments Using a Probable Observation Data Set-Based EKF Method |
Abstract:
We report a new filter to assist the search for rare bird species. Since a rare bird only appears in front of a camera with very low occurrence (e.g., less than ten times per year) for very short duration (e.g., less than a fraction of a second), our algorithm must have a very low false negative rate. We verify the bird body axis information with the known bird flying dynamics from the short video segment. Since a regular extended Kalman filter (EKF) cannot converge due to high measurement error and limited data, we develop a novel probable observation data set (PODS)-based EKF method. The new PODS-EKF searches the measurement error range for all probable observation data that ensures the convergence of the corresponding EKF in short time frame. The algorithm has been extensively tested using both simulated inputs and real video data of four representative bird species. In the physical experiments, our algorithm has been tested on rock pigeons and red-tailed hawks with 119 motion sequences. The area under the ROC curve is 95.0%. During the one-year search of ivory-billed woodpeckers, the system reduces the raw video data of 29.41TB to only 146.7 MB (reduction rate 99.9995%). |
| Autors: Song, D.;Xu, Y.; |
| Appeared in: IEEE Transactions on Image Processing |
| Publication date: Sep 2010, volume: 19, issue:9, pages: 2321 - 2331 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Phase-Noise Multi-Phase Oscillator Based on Left-Handed LC-Ring |
Abstract:
This paper presents a distributed multi-phase oscillator based on left-handed LC-ring. In contrast to traditional designs that couple multiple LC-tanks through MOSFETs, it uses an LC-ring as a single high-order resonator that generates multi-phase resonant signal. By avoiding coupling MOSFETs which deteriorate phase noise significantly, it can synthesize multiple phases while maintaining the same phase-noise figure-of-merit (FoM) as a single-stage LC oscillator. This also provides a systematic way of trading power for phase noise. The dynamics and the phase noise of the LC-ring oscillator are analyzed based on a mode-decomposition model. We also address the duality of left-/right-handed resonator in the context of oscillator in detail. These analysis was verified by prototypes in a 0.13 $mu{hbox {m}}$ CMOS process with 0.5 V supply voltage: a four-stage LC-ring oscillator at 5.12 GHz draws 8 mA current and achieves a phase noise of $-$121.6 dBc/Hz@600 kHz, while a single-stage one at 5.34 GHz draws 2 mA and achieves $-$116.1 dBc/Hz@600 kHz. There is a good agreement among analysis, simulation, and measurement. |
| Autors: Li, G.;Afshari, E.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1822 - 1833 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Power DSP for Wireless Communications |
Abstract:
This paper proposes a low-power high-throughput digital signal processor (DSP) for baseband processing in wireless terminals. It builds on our earlier architecture—Signal processing On Demand Architecture (SODA)—which is a four-processor, 32-lane SIMD machine that was optimized for WCDMA 2 Mbps and IEEE 802.11a. SODA has several shortcomings including large register file power, wasted cycles for data alignment, etc., and cannot satisfy the higher throughput and lower power requirements of emerging standards. We propose SODA-II, which addresses these problems by deploying the following schemes: operation chaining, pipelined execution of SIMD units, staggered memory access, and multicycling of computation units. Operation chaining involves chaining the primitive instructions, thereby eliminating unnecessary register file accesses and saving power. Pipelined execution of the vector instructions through the SIMD units improves the system throughput. Staggered execution of computation units helps simplify the data alignment networks. It is implemented in conjunction with multicycling so that the computation units are busy most of the time. The proposed architecture is evaluated with an in-house architecture emulator which uses component-level area and power models built with Synopsys and Artisan tools. Our results show that for WCDMA 2 Mbps, the proposed architecture uses two processors and consumes only 120 mW while SODA uses four processors and consumes 210 mW when implemented in 0.13-$muhbox {m}$ technology and clocked at 300 MHz. |
| Autors: Lee, H.;Chakrabarti, C.;Mudge, T.; |
| Appeared in: IEEE Transactions on Very Large Scale Integration Systems |
| Publication date: Sep 2010, volume: 18, issue:9, pages: 1310 - 1322 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Lower Bound on the Optimum Distance Profiles of the Second-Order Reed–Muller Codes |
Abstract:
In this paper, we give a lower bound for the optimum distance profiles of the second-order Reed–Muller code in the dictionary order and in the inverse dictionary order. In particular, we investigate the second-order Reed–Muller codes of length ${leq}256$. We show that the bound is tight in both orders for the codes of length ${leq}128$ . |
| Autors: Chen, Y.;Han Vinck, A. J.; |
| Appeared in: IEEE Transactions on Information Theory |
| Publication date: Sep 2010, volume: 56, issue:9, pages: 4309 - 4320 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Measure of Machine Intelligence |
Abstract:
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| Autors: Cochrane, P.; |
| Appeared in: Proceedings of the IEEE |
| Publication date: Sep 2010, volume: 98, issue:9, pages: 1543 - 1545 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Molecular-Rotor Device for Nonvolatile High-Density Memory Applications |
Abstract:
A novel memory device based on an electrically driven molecular rotor was fabricated and demonstrated to have bistable switching effects. The device showed an on/off ratio of approximately $ hbox{10}^{4}$, a read window of about 2.5 V, and retention performance of greater than $hbox{10}^{4} hbox{s}$. The analysis of the device $I$–$V$ characteristics suggests the source of the observed switching effects to be the redox-induced ligand rotation around the copper metal center, which is consistent with the observed temperature dependence of the switching behavior. This organic monolayer device holds a potential for nonvolatile high-density memory applications due to its scalability and reduced cost. |
| Autors: Xue, M.;Kabehie, S.;Stieg, A. Z.;Tkatchouk, E.;Benitez, D.;Goddard, W. A.;Zink, J. I.;Wang, K. L.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 1047 - 1049 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Multiresolution Approach to Iterative Reconstruction Algorithms in X-Ray Computed Tomography |
Abstract:
In computed tomography, the application of iterative reconstruction methods in practical situations is impeded by their high computational demands. Especially in high resolution X-ray computed tomography, where reconstruction volumes contain a high number of volume elements (several giga voxels), this computational burden prevents their actual breakthrough. Besides the large amount of calculations, iterative algorithms require the entire volume to be kept in memory during reconstruction, which quickly becomes cumbersome for large data sets. To overcome this obstacle, we present a novel multiresolution reconstruction, which greatly reduces the required amount of memory without significantly affecting the reconstructed image quality. It is shown that, combined with an efficient implementation on a graphical processing unit, the multiresolution approach enables the application of iterative algorithms in the reconstruction of large volumes at an acceptable speed using only limited resources. |
| Autors: De Witte, Y.;Vlassenbroeck, J.;Van Hoorebeke, L.; |
| Appeared in: IEEE Transactions on Image Processing |
| Publication date: Sep 2010, volume: 19, issue:9, pages: 2419 - 2427 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Neural Network of Smooth Hinge Functions |
Abstract:
Smooth hinging hyperplane (SHH) has been proposed as an improvement over the well-known hinging hyperplane (HH) by the fact that it retains the useful features of HH while overcoming HH's drawback of nondifferentiability. This paper introduces a formal characterization of smooth hinge function (SHF), which can be used to generate SHH as a neural network. A method for the general construction of SHF is also given. Furthermore, the work proves that SHH is better than HH in functional approximation, i.e., the optimal error of SHH approximating a general function is always smaller or equal to that of HH. Particularly, in the case that the SHF is generated via the integration of a class of sigmoidal functions, it is further proven that the corresponding SHH of the $2m$ SHFs would outperform a neural network with $m$ of the sigmoidal function from which the SHF is derived. Any upper bound established on the approximation error of a neural network of $m$ sigmoidal activation functions can hence be translated to the SHH of $m$ SHFs by replacing $m$ with ${{m}over{2}}$. The work also includes an algorithm for the identification of SHH making use of its differentiability property. Simulation experiments are presented to validate the theoretical conclusions to possible extent. |
| Autors: Wang, S.;Huang, X.;Yam, Y.; |
| Appeared in: IEEE Transactions on Neural Networks |
| Publication date: Sep 2010, volume: 21, issue:9, pages: 1381 - 1395 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Control Method for Power-Assisted Wheelchair Based on the Surface Myoelectric Signal |
Abstract:
In this paper, we design a new controller for power-assisted wheelchairs. Conventional power-assist controllers only focus on the amplification of the human input force using torque sensor. Our proposed controller does not use a torque sensor but an electromyogram sensor to estimate the driver's intention. We also use a disturbance observer to compensate for the lack of propelling torque information since it is difficult to simply regard the myoelectric signals as propelling torque. Then, we decide assist torque by combining the filtered myoelectric signals and the estimated human torque signal calculated by the disturbance observer. Experimental results show that the proposed power-assist method realizes fast, stable, and smooth acceleration. |
| Autors: Oonishi, Y.;Oh, S.;Hori, Y.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 3191 - 3196 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A new Lagrangian density for all four Maxwell's equations |
Abstract:
In 2008 Civelek and Bechteler obtained a Lagrangian density which can lead to all four Maxwell's equations by separately using two groups of constraints.In this communication, a new Lagrangian density is established, which can directly lead to all four Maxwell's equations by simply using one group of constraints. |
| Autors: Cheng-Bo, Zheng , Zuo-Jun, Wang |
| Appeared in: International Journal of Engineering Science |
| Publication date: Sep 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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|
| » A New MPPT Method for Low-Power Solar Energy Harvesting |
Abstract:
This paper describes a new maximum-power-point-tracking (MPPT) method focused on low-power ( $< 1$ W) photovoltaic (PV) panels. The static and dynamic performance is theoretically analyzed, and design criteria are provided. A prototype was implemented with a 500-mW PV panel, a commercial boost converter, and low-power components for the MPPT controller. Laboratory measurements were performed to assess the effectiveness of the proposed method. Tracking efficiency was higher than 99.6%. The overall efficiency was higher than 92% for a PV panel power higher than 100 mW. This is, in part, feasible due to the low power consumption of the MPPT controller, which was kept lower than 350 ${rm mu}hbox{W}$. The time response of the tracking circuit was tested to be around 1 s. Field measurements showed energy gains higher than 10.3% with respect to a direct-coupled solution for an ambient temperature of 26 $^{circ}hbox{C}$. Higher gains are expected for lower temperatures. |
| Autors: Lopez-Lapena, O.;Penella, M. T.;Gasulla, M.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 3129 - 3138 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A new result on stability analysis for stochastic neutral systems? |
Abstract:
This paper discusses the mean-square exponential stability of stochastic linear systems of neutral type. Applying the Lyapunov-Krasovskii theory, a linear matrix inequality-based delay-dependent stability condition is presented. The use of model transformations, cross-term bounding techniques or additional matrix variables is all avoided, thus the method leads to a simple criterion and shows less conservatism. The new result is derived based on the generalized Finsler lemma (GFL). GFL reduces to the standard Finsler lemma in the absence of stochastic perturbations, and it can be used in the analysis and synthesis of stochastic delay systems. Moreover, GFL is also employed to obtain... |
| Autors: Yun, Chen , Wei Xing, Zheng , Anke, Xue |
| Appeared in: Automatica |
| Publication date: Sep 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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|
| » A New Universal Generating Function Method for Estimating the Novel Multiresource Multistate Information Network Reliability |
Abstract:
In this article, we introduce a special novel multistate network that permits multiresource to be transmitted from the source node to multiple targets simultaneously without satisfying the flow conservation law. This network is called the multiresource multistate information network (MMIN). The one-to-many-targets (i.e. one-to-all-target-subset) reliability problem of the MMIN is considered next under limited cost and capacity constraints. A straightforward, exact algorithm derived from the universal generating function method (UGFM) is developed for this new problem. The correctness and computational complexity of the proposed UGFM will be analysed and proven. One example is given to illustrate how MMIN reliability is evaluated using the proposed UGFM. |
| Autors: Yeh, W.-C.;He, X.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Sep 2010, volume: 59, issue:3, pages: 528 - 538 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Vector Waveform Inversion Algorithm for Simultaneous Updating of Conductivity and Permittivity Parameters From Combination Crosshole/Borehole-to-Surface GPR Data |
Abstract:
We have developed a new full-waveform groundpenetrating radar (GPR) multicomponent inversion scheme for imaging the shallow subsurface using arbitrary recording configurations. It yields significantly higher resolution images than conventional tomographic techniques based on first-arrival times and pulse amplitudes. The inversion is formulated as a nonlinear least squares problem in which the misfit between observed and modeled data is minimized. The full-waveform modeling is implemented by means of a finite-difference time-domain solution of Maxwell's equations. We derive here an iterative gradient method in which the steepest descent direction, used to update iteratively the permittivity and conductivity distributions in an optimal way, is found by cross-correlating the forward vector wavefield and the backward-propagated vectorial residual wavefield. The formulation of the solution is given in a very general, albeit compact and elegant, fashion. Each iteration step of our inversion scheme requires several calculations of propagating wavefields. Novel features of the scheme compared to previous full-waveform GPR inversions are as follows: 1) The permittivity and conductivity distributions are updated simultaneously (rather than consecutively) at each iterative step using improved gradient and step length formulations; 2) the scheme is able to exploit the full vector wavefield; and 3) various data sets/survey types (e.g., crosshole and borehole-to-surface) can be individually or jointly inverted. Several synthetic examples involving both homogeneous and layered stochastic background models with embedded anomalous inclusions demonstrate the superiority of the new scheme over previous approaches. |
| Autors: Meles, G. A.;Van der Kruk, J.;Greenhalgh, S. A.;Ernst, J. R.;Maurer, H.;Green, A. G.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Sep 2010, volume: 48, issue:9, pages: 3391 - 3407 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Novel Characterization Scheme of  Interface Roughness for Surface Roughness Scattering-Limited Mobilities of Electrons and Holes in Unstrained- and Strained-Si MOSFETs |
Abstract:
In this paper, a novel method to directly determine the surface roughness scattering-limited mobilities $(mu_{rm sr})$ of electrons and holes in Si MOSFETs from the experimental data of MOS interface roughness is proposed and compared with the experimental $mu_{rm sr}$ of Si MOSFETs with and without biaxial tensile strain. This method includes the direct evaluation of the scattering potential from the power spectra of $hbox{Si/SiO}_{2}$ interface roughness data, which are taken through high-resolution advanced transmission electron microscopy measurements, without assuming any autocorrelation function form of the interface roughness, like a Gaussian or exponential function. It is found, for the first time, that, by employing the present method, experimental electron and hole $mu_{rm sr}$ (both unstrained and strained Si) could be presented by a same model. As a result, the difference in strain dependence between electron and hole $mu_{rm sr}$ , which has experimentally been observed, is systematically explained by the change of power spectra of the interface roughness due to strain. |
| Autors: Zhao, Y.;Matsumoto, H.;Sato, T.;Koyama, S.;Takenaka, M.;Takagi, S.; |
| Appeared in: IEEE Transactions on Electron Devices |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2057 - 2066 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Distributed Brillouin Sensor Based on Optical Differential Parametric Amplification |
Abstract:
We propose and demonstrate a novel distributed sensor based on coherent interaction of the Brillouin gain and loss via optical differential parametric amplification (ODPA), which provides narrowed parametric Brillouin gain spectrum, strong Brillouin signal via differential gain, and short measurement time simultaneously. In experiment, a 0.5 m spatial resolution with a strain accuracy of $6 mu varepsilon$ is realized by using 20/15 ns Stokes and anti-Stokes pulse pair in a 15 m polarization-maintaining fiber. The spectrum narrowing phenomenon in ODPA Brillouin sensor is discussed. |
| Autors: Li, Y.;Bao, X.;Dong, Y.;Chen, L.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2621 - 2626 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Five-Photomask Low-Temperature Polycrystalline Silicon CMOS Structure for AMLCD Application |
Abstract:
A novel five-mask low-temperature polycrystalline silicon (LTPS) CMOS structure was verified by manufacturing the thin-film transistor test samples using the proposed five-mask LTPS CMOS process. In integrating the five-mask CMOS structure, a selective contact barrier metal formation process was developed, without additional photomask steps, to solve the issue of high-contact-resistance problem encountered inevitably in the contact between the indium tin oxide and doped polycrystalline silicon (poly-Si) source–drain layers. The five-mask CMOS technology was also confirmed by manufacturing a five-mask CMOS panel for the active-matrix liquid-crystal-display application. |
| Autors: Lee, S.-J.;Lee, S.-W.;Oh, K.-M.;Park, S.-J.;Lee, K.-E.;Yoo, Y.-S.;Lim, K.-M.;Yang, M.-S.;Yang, Y.-S.;Hwang, Y.-K.; |
| Appeared in: IEEE Transactions on Electron Devices |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2324 - 2329 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Hierarchical Method of Ship Detection from Spaceborne Optical Image Based on Shape and Texture Features |
Abstract:
Ship detection from remote sensing imagery is very important, with a wide array of applications in areas such as fishery management, vessel traffic services, and naval warfare. This paper focuses on the issue of ship detection from spaceborne optical images (SDSOI). Although advantages of synthetic-aperture radar (SAR) result in that most of current ship detection approaches are based on SAR images, disadvantages of SAR still exist, such as the limited number of SAR sensors, the relatively long revisit cycle, and the relatively lower resolution. With the increasing number of and the resulting improvement in continuous coverage of the optical sensors, SDSOI can partly overcome the shortcomings of SAR-based approaches and should be investigated to help satisfy the requirements of real-time ship monitoring. In SDSOI, several factors such as clouds, ocean waves, and small islands affect the performance of ship detection. This paper proposes a novel hierarchical complete and operational SDSOI approach based on shape and texture features, which is considered a sequential coarse-to-fine elimination process of false alarms. First, simple shape analysis is adopted to eliminate evident false candidates generated by image segmentation with global and local information and to extract ship candidates with missing alarms as low as possible. Second, a novel semisupervised hierarchical classification approach based on various features is presented to distinguish between ships and nonships to remove most false alarms. Besides a complete and operational SDSOI approach, the other contributions of our approach include the following three aspects: 1) it classifies ship candidates by using their class probability distributions rather than the direct extracted features; 2) the relevant classes are automatically built by the samples’ appearances and their feature attribute in a semisupervised mode; and 3) besides commonly used shape and texture features, a new texture operator, i.e-
-
., local multiple patterns, is introduced to enhance the representation ability of the feature set in feature extraction. Experimental results of SDSOI on a large image set captured by optical sensors from multiple satellites show that our approach is effective in distinguishing between ships and nonships, and obtains a satisfactory ship detection performance. |
| Autors: Zhu, C.;Zhou, H.;Wang, R.;Guo, J.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Sep 2010, volume: 48, issue:9, pages: 3446 - 3456 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Instantaneous Torque Control Scheme for Induction Generator Systems |
Abstract:
In this paper, a novel instantaneous torque control is proposed to control the output voltage of a stand-alone induction generator. The output voltage regulation is achieved by the fast control of the space voltage vector based on the information of the output voltage and output current, which leads to a better system dynamic performance. The simulation and experimental results verify the effectiveness of the proposed scheme. The control scheme for the voltage buildup process is investigated as well. |
| Autors: Hu, Y.;Huang, W.;Li, Y.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Sep 2010, volume: 25, issue:3, pages: 795 - 803 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Parallel Computing Platform for Real-Time Haptic Interaction with Deformable Bodies |
Abstract:
Real-time simulation of haptic interaction with deformable objects is computationally demanding. In particular in finite-element (FE) based analysis of such interactions, a large system of equations must be solved at an update rate of 100-1,000 Hz for simulation fidelity and stability. A new hardware-based parallel implementation of a Preconditioned Conjugate Gradient (PCG) algorithm is proposed for solving the linear systems of equations arising from FE-based deformation models. Concurrent utilization of a large number of fixed-point computing units on a Field-Programmable Gate Array (FPGA) device yields a very fast solution to these equations. Quantization and overflow errors in the fixed-point implementation of the iterative solver are minimized through dynamic scaling and preconditioning. Numerical accuracy of the solution, the architecture design, and issues pertaining to the degree of parallelism and scalability of the architecture are discussed in detail. The implementation of the solver on an Altera EP3SE110 FPGA device has enabled real-time simulation of three-dimensional linear elastic deformation models with 1,500 nodes at an update rate of up to 2,500 Hz. |
| Autors: Mafi, Ramin;Sirouspour, Shahin;Mahdavikhah, Behzad;Moody, Brian;Elizeh, Kaveh;Kinsman, Adam;Nicolici, Nicola; |
| Appeared in: IEEE Transactions on Haptics |
| Publication date: Sep 2010, volume: 3, issue:3, pages: 211 - 223 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Physical Model for Post-Breakdown Digital Gate Current Noise |
Abstract:
We present a new physical model that enables us to reproduce the digital gate current random telegraph noise fluctuations observed in ultrathin SiON dielectrics in the early stages of post-breakdown (BD). Gate current $(I_{G})$ fluctuations are modeled assuming that some traps in the BD path switch between two unstable configurations, corresponding to neutral and negatively charged O vacancies. The energy levels of the trap considered in simulations here are consistent with the values calculated from atomistic simulations. The model allows one to reproduce accurately the mean and variation in the $I_{G}$ fluctuations observed on 16- and 22- $hbox{rm{AA}}$-thick SiON gate dielectrics at different gate voltages. |
| Autors: Padovani, A.;Morassi, L.;Raghavan, N.;Larcher, L.;Wenhu, W.;Pey, K. L.;Bersuker, G.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 1032 - 1034 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A PVDF Receiver for Ultrasound Monitoring of Transcranial Focused Ultrasound Therapy |
Abstract:
Focused ultrasound (FUS) shows great promise for use in the area of transcranial therapy. Currently dependent on MRI for monitoring, transcranial FUS would benefit from a real-time technique to monitor acoustic emissions during therapy. A polyvinylidene fluoride receiver with an active area of 17.8 mm$^2$ and a film thickness of 110 $mu$m was constructed. A compact preamplifier was designed to fit within the receiver to improve the receiver SNR and allow the long transmission line needed to remove the receiver electronics outside of the MRI room. The receiver was compared with a 0.5 mm commercial needle hydrophone and focused and unfocused piezoceramics. The receiver was found to have a higher sensitivity than the needle hydrophone, a more wideband response than the piezoceramic, and sufficient threshold for detection of microbubble emissions. Sonication of microbubbles directly and through a fragment of human skull demonstrated the ability of the receiver to detect harmonic bubble emissions, and showed potential for use in a larger scale array. Monitoring of disruption of the blood–brain barrier in rats showed functionality in vivo and the ability to detect subharmonic, harmonic, and wideband emissions during therapy. The receiver shows potential for monitoring acoustic emissions during treatments and providing additional parameters to assist treatment planning. Future work will focus on developing a multi-element array for transcranial treatment monitoring. |
| Autors: O’Reilly, M. A.;Hynynen, K.; |
| Appeared in: IEEE Transactions on Biomedical Engineering |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2286 - 2294 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Quantum Version of Wielandt's Inequality |
Abstract:
In this paper, Wielandt's inequality for classical channels is extended to quantum channels. That is, an upper bound to the number of times a channel must be applied, so that it maps any density operator to one with full rank, is found. Using this bound, dichotomy theorems for the zero-error capacity of quantum channels and for the Matrix Product State (MPS) dimension of ground states of frustration-free Hamiltonians are derived. The obtained inequalities also imply new bounds on the required interaction-range of Hamiltonians with unique MPS ground state. |
| Autors: Sanz, M.;Perez-Garcia, D.;Wolf, M. M.;Cirac, J. I.; |
| Appeared in: IEEE Transactions on Information Theory |
| Publication date: Sep 2010, volume: 56, issue:9, pages: 4668 - 4673 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A randomized countermeasure against parasitic adversaries in wireless sensor networks |
Abstract:
Due to their limited capabilities, wireless sensor nodes are subject to physical attacks that are hard to defend against. In this paper, we first identify a typical attacker, called parasitic adversary, who seeks to exploit sensor networks by obtaining measurements in an unauthorized way. As a countermeasure, we first employ a randomized key refreshing: with low communication cost, it aims at confining (but not eliminating) the effects of the adversary. Moreover, our low-complexity solution, GossiCrypt, leverages on the large scale of sensor networks to protect data confidentiality, efficiently and effectively. GossiCrypt applies symmetric key encryption to data at their source nodes; and it applies re-encryption at a randomly chosen subset of nodes en route to the sink. The combination of randomized key refreshing and GossiCrypt protects data confidentiality with a probability of almost 1; we show this analytically and with simulations. In addition, the energy consumption of GossiCrypt is lower than a public-key based solution by several orders of magnitude. |
| Autors: Papadimitratos, P.;Jun Luo;Hubaux, J.-P.; |
| Appeared in: IEEE Journal on Selected Areas in Communications |
| Publication date: Sep 2010, volume: 28, issue:7, pages: 1036 - 1045 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Registration-Based Propagation Framework for Automatic Whole Heart Segmentation of Cardiac MRI |
Abstract:
Magnetic resonance (MR) imaging has become a routine modality for the determination of patient cardiac morphology. The extraction of this information can be important for the development of new clinical applications as well as the planning and guidance of cardiac interventional procedures. To avoid inter- and intra-observer variability of manual delineation, it is highly desirable to develop an automatic technique for whole heart segmentation of cardiac magnetic resonance images. However, automating this process is complicated by the limited quality of acquired images and large shape variation of the heart between subjects. In this paper, we propose a fully automatic whole heart segmentation framework based on two new image registration algorithms: the locally affine registration method (LARM) and the free-form deformations with adaptive control point status (ACPS FFDs). LARM provides the correspondence of anatomical substructures such as the four chambers and great vessels of the heart, while the registration using ACPS FFDs refines the local details using a constrained optimization scheme. We validated our proposed segmentation framework on 37 cardiac MR volumes on the end-diastolic phase, displaying a wide diversity of morphology and pathology, and achieved a mean accuracy of 2.14 $pm$ 0.63 mm (rms surface distance) and a maximal error of 4.31 mm. |
| Autors: Zhuang, X.;Rhode, K. S.;Razavi, R. S.;Hawkes, D. J.;Ourselin, S.; |
| Appeared in: IEEE Transactions on Medical Imaging |
| Publication date: Sep 2010, volume: 29, issue:9, pages: 1612 - 1625 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Regulator for Pressure-Controlled Total-Liquid Ventilation |
Abstract:
Total-liquid ventilation (TLV) is an innovative experimental method of mechanical-assisted ventilation in which lungs are totally filled and then ventilated with a tidal volume of perfluorochemical liquid by using a dedicated liquid ventilator. Such a novel medical device must resemble other conventional ventilators: it must be able to conduct controlled-pressure ventilation. The objective was to design a robust controller to perform pressure-regulated expiratory flow and to implement it on our latest liquid-ventilator prototype (Inolivent-4). Numerical simulations, in vitro experiments, and in vivo experiments in five healthy term newborn lambs have demonstrated that it was efficient to generate expiratory flows while avoiding collapses. Moreover, the in vivo results have demonstrated that our liquid ventilator can maintain adequate gas exchange, normal acid–base equilibrium, and achieve greater minute ventilation, better oxygenation and $hbox{CO}_{2}$ extraction, while nearing flow limits. Hence, it is our suggestion to perform pressure-controlled ventilation during expiration with minute ventilation equal or superior to $140, hbox{mL}{kern1pt}{cdot}{kern1pt} hbox{min}^{-1}{kern1pt}{cdot}{kern1pt} hbox{kg}^{-1}$ in order to ensure $hbox{PaCO}_{2}$ below 55 mmHg. From a clinician's point of view, pressure-controlled ventilation greatly simplifies the use of the liquid ventilator, which will certainly facilitate its introduction in intensive care units for clinical applications. |
| Autors: Robert, R.;Micheau, P.;Avoine, O.;Beaudry, B.;Beaulieu, A.;Walti, H.; |
| Appeared in: IEEE Transactions on Biomedical Engineering |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2267 - 2276 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Resistive Mesh Phantom for Assessing the Performance of EIT Systems |
Abstract:
Assessing the performance of electrical impedance tomography (EIT) systems usually requires a phantom for validation, calibration, or comparison purposes. This paper describes a resistive mesh phantom to assess the performance of EIT systems while taking into account cabling stray effects similar to in vivo conditions. This phantom is built with 340 precision resistors on a printed circuit board representing a 2-D circular homogeneous medium. It also integrates equivalent electrical models of the Ag/AgCl electrode impedances. The parameters of the electrode models were fitted from impedance curves measured with an impedance analyzer. The technique used to build the phantom is general and applicable to phantoms of arbitrary shape and conductivity distribution. We describe three performance indicators that can be measured with our phantom for every measurement of an EIT data frame: SNR, accuracy, and modeling accuracy. These performance indicators were evaluated on our EIT system under different frame rates and applied current intensities. The performance indicators are dependent on frame rate, operating frequency, applied current intensity, measurement strategy, and intermodulation distortion when performing simultaneous measurements at several frequencies. These parameter values should, therefore, always be specified when reporting performance indicators to better appreciate their significance. |
| Autors: Gagnon*, H.;Cousineau, M.;Adler, A.;Hartinger, A. E.; |
| Appeared in: IEEE Transactions on Biomedical Engineering |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2257 - 2266 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A simple and scalable algorithm for alignment in broadcast networks |
Abstract:
We consider the problem of coordinating a group of mobile nodes communicating through a wireless medium. The objective of the network is the alignment of all the nodes towards a common direction through local interactions, without the need for global knowledge such as the network topology or the maximum degree of the network, or even local parameters, such as the number of neighbors. The key feature of our algorithm is that each node state update is done through voting, where the probability of each vote is biased by the state of the node neighbors. We propose two possible physical implementations for our algorithm. The first is based on the explicit exchange of packetized messages, while the second is a cross-layer approach. Our analysis unveils key convergence properties of this simple class of alignment algorithms, via analytical and simulated results. |
| Autors: Pagliari, R.;Yildiz, M.E.;Kirti, S.;Morgansen, K.A.;Javidi, T.;Scaglione, A.; |
| Appeared in: IEEE Journal on Selected Areas in Communications |
| Publication date: Sep 2010, volume: 28, issue:7, pages: 1190 - 1199 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Simple Demodulation Method for FBG Temperature Sensors Using a Narrow Band Wavelength Tunable DFB Laser |
Abstract:
A simple demodulation method for a fiber Bragg grating (FBG) temperature sensor is proposed and demonstrated, which uses a low cost commercial temperature-controlled wavelength scanning distributed-feedback (DFB) laser, a sensing FBG and a low-speed photodetector (PD). Relative high resolution is achieved by utilizing an FBG with enhanced temperature sensitivity design. Such a method may be suitable for applications requiring moderate resolution and low cost implementations. |
| Autors: Yan, L. S.;Yi, A.;Pan, W.;Luo, B.; |
| Appeared in: IEEE Photonics Technology Letters |
| Publication date: Sep 2010, volume: 22, issue:18, pages: 1391 - 1393 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Single-VCO Fractional-  Frequency Synthesizer for Digital TV Tuners |
Abstract:
A single-voltage-controlled-oscillator (VCO) fractional-$N$ frequency synthesizer is designed for Advanced Television Systems Committee, Digital Video Broadcasting-Terrestrial, and Integrated Services Digital Broadcasting-Terrestrial digital television tuners. This frequency synthesizer can cover all the frequency bands for all three standards with only one VCO, and thus, the chip area as well as the power consumption can be greatly reduced. Different channel spacing requirements can be fulfilled by fractional synthesis. A dynamic frequency calibration loop is also used to automatically choose the coarse setting of the VCO. The synthesizer was fabricated in a standard $0.13hbox{-}muhbox{m}$ complementary metal–oxide–semiconductor process and draws 14 mA from a 1.2-V supply. The measured phase noise is lower than $-$80 dBc/Hz from 1 to 100 kHz offset and $-$100 dBc/Hz at 1 MHz offset. The active area of the frequency synthesizer is smaller than 0.54 $hbox{mm}^{2}$. |
| Autors: Yang, Y.-C.;Lu, S.-S.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 3207 - 3215 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Situation-Adaptive Lane-Keeping Support System: Overview of the SAFELANE Approach |
Abstract:
Going beyond standard lane-departure-avoidance systems, this paper addresses the development of a system that is able to deal with a large set of different traffic situations. Its foundation lies on a thoroughly constituted environment detection through which a decision system is built. From the output of the decision module, the driver is warned or corrected through suited actuators that are coupled to control strategies. The input to the system comes from cameras, which are supplemented by active sensors (such as radar and laser scanners) and vehicle dynamic data, digital road maps, and precise vehicle-positioning data. In this paper, the presented system design is divided into three layers: the perception layer, which is responsible for the environment perception, and the decision and action layers, which are responsible for evaluating and executing actions, respectively. |
| Autors: Amditis, A.;Bimpas, M.;Thomaidis, G.;Tsogas, M.;Netto, M.;Mammar, S.;Beutner, A.;Mohler, N.;Wirthgen, T.;Zipser, S.;Etemad, A.;Da Lio, M.;Cicilloni, R.; |
| Appeared in: IEEE Transactions on Intelligent Transportation Systems |
| Publication date: Sep 2010, volume: 11, issue:3, pages: 617 - 629 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Spatially Selective Correlative Filtration Method Based on the Multiscale Edge Shift-Correlative Technique |
Abstract:
In terms of signal denoising, filtering out high-frequency noise while effectively preserving the useful high-frequency information is a hot topic for research. In this paper, we propose a wavelet modulus maxima spatially selective correlative filtration (SSCF) algorithm to filter out the high-frequency noise mixed in the useful signals. The proposed algorithm is different from traditional noise filtration algorithms in that it need not estimate noise and is not easily affected by noise. The SSCF algorithm first searches the modulus maxima from the multiscale wavelet coefficients of the signal and analyzes the corresponding edge information. Then, it identifies the noise components and useful components from the edge information. For noise components, the algorithm smoothes them away. For useful edge information, the algorithm aligns the corresponding modulus maxima in the wavenumber domain using the shift-related technique. This process amends the “drift” phenomenon of modulus maxima across scales. Next, the proposed algorithm multiplies the aligned multiscale wavelet coefficients that can strengthen the useful signal and attenuate the noise information. We apply the proposed SSCF algorithm to denoise the infrared absorption spectrum of electric insulation gas SF6. Experiments show that the proposed scheme can effectively suppress noise and, at the same time, preserving the useful components. |
| Autors: Liu, Y.;Tao, W. L.;Liu, K.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Sep 2010, volume: 59, issue:9, pages: 2280 - 2285 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Speed-Adaptive Reduced-Order Observer for Sensorless Vector Control of Doubly Fed Induction Generator-Based Variable-Speed Wind Turbines |
Abstract:
In this paper, a speed-adaptive reduced-order observer for sensorless vector control of doubly fed induction generators (DFIGs) is proposed. The observer is a simulation of the rotor current dynamic model with feedback of the estimation error and a speed-adaptation loop. Feedback and adaptation gains are designed based on the closed-loop observer model. A parameter sensitivity analysis reveals that this observer is robust against machine parameter variations in the normal operating regions. Simulation results demonstrate desired steady-state and dynamic performance of this sensorless control approach for DFIG-based variable-speed wind turbines. |
| Autors: Yang , S.;Ajjarapu, V.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Sep 2010, volume: 25, issue:3, pages: 891 - 900 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Statistical Framework for Optimal Design Matrix Generation With Application to fMRI |
Abstract:
The general linear model (GLM) is a well established tool for analyzing functional magnetic resonance imaging (fMRI) data. Most fMRI analyses via GLM proceed in a massively univariate fashion where the same design matrix is used for analyzing data from each voxel. A major limitation of this approach is the locally varying nature of signals of interest as well as associated confounds. This local variability results in a potentially large bias and uncontrolled increase in variance for the contrast of interest. The main contributions of this paper are two fold: 1) we develop a statistical framework that enables estimation of an optimal design matrix while explicitly controlling the bias variance decomposition over a set of potential design matrices and 2) we develop and validate a numerical algorithm for computing optimal design matrices for general fMRI data sets. The implications of this framework include the ability to match optimally the magnitude of underlying signals to their true magnitudes while also matching the “null” signals to zero size thereby optimizing both the sensitivity and specificity of signal detection. By enabling the capture of multiple profiles of interest using a single contrast (as opposed to an F-test) in a way that optimizes for both bias and variance enables the passing of first level parameter estimates and their variances to the higher level for group analysis which is not possible using F-tests. We demonstrate the application of this approach to in vivo pharmacological fMRI data capturing the acute response to a drug infusion, to task-evoked, block design fMRI and to the estimation of a haemodynamic response function (HRF) in event-related fMRI. Although developed with motivation from fMRI, our framework is quite general and has potentially wide applicability to a variety of disciplines. |
| Autors: Pendse, G. V.;Baumgartner, R.;Schwarz, A. J.;Coimbra, A.;Borsook, D.;Becerra, L.; |
| Appeared in: IEEE Transactions on Medical Imaging |
| Publication date: Sep 2010, volume: 29, issue:9, pages: 1573 - 1611 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Statistical Pixel Intensity Model for Segmentation of Confocal Laser Scanning Microscopy Images |
Abstract:
Confocal laser scanning microscopy (CLSM) has been widely used in the life sciences for the characterization of cell processes because it allows the recording of the distribution of fluorescence-tagged macromolecules on a section of the living cell. It is in fact the cornerstone of many molecular transport and interaction quantification techniques where the identification of regions of interest through image segmentation is usually a required step. In many situations, because of the complexity of the recorded cellular structures or because of the amounts of data involved, image segmentation either is too difficult or inefficient to be done by hand and automated segmentation procedures have to be considered. Given the nature of CLSM images, statistical segmentation methodologies appear as natural candidates. In this work we propose a model to be used for statistical unsupervised CLSM image segmentation. The model is derived from the CLSM image formation mechanics and its performance is compared to the existing alternatives. Results show that it provides a much better description of the data on classes characterized by their mean intensity, making it suitable not only for segmentation methodologies with known number of classes but also for use with schemes aiming at the estimation of the number of classes through the application of cluster selection criteria. |
| Autors: Calapez, A.;Rosa, A.; |
| Appeared in: IEEE Transactions on Image Processing |
| Publication date: Sep 2010, volume: 19, issue:9, pages: 2408 - 2418 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Study of Hierarchical and Flat Classification of Proteins |
Abstract:
Automatic classification of proteins using machine learning is an important problem that has received significant attention in the literature. One feature of this problem is that expert-defined hierarchies of protein classes exist and can potentially be exploited to improve classification performance. In this article, we investigate empirically whether this is the case for two such hierarchies. We compare multiclass classification techniques that exploit the information in those class hierarchies and those that do not, using logistic regression, decision trees, bagged decision trees, and support vector machines as the underlying base learners. In particular, we compare hierarchical and flat variants of ensembles of nested dichotomies. The latter have been shown to deliver strong classification performance in multiclass settings. We present experimental results for synthetic, fold recognition, enzyme classification, and remote homology detection data. Our results show that exploiting the class hierarchy improves performance on the synthetic data but not in the case of the protein classification problems. Based on this, we recommend that strong flat multiclass methods be used as a baseline to establish the benefit of exploiting class hierarchies in this area. |
| Autors: Zimek, Arthur;Buchwald, Fabian;Frank, Eibe;Kramer, Stefan; |
| Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics |
| Publication date: Sep 2010, volume: 7, issue:3, pages: 563 - 571 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Study of the LCMV and MVDR Noise Reduction Filters |
Abstract:
In real-world environments, the signals captured by a set of microphones in a speech communication system are mixtures of the desired signal, interference, and ambient noise. A promising solution for proper speech acquisition (with reduced noise and interference) in this context consists in using the linearly constrained minimum variance (LCMV) beamformer to reject the interference, reduce the overall mixture energy, and preserve the target signal. The minimum variance distortionless response beamformer (MVDR) is also commonly known to reduce the interference-plus-noise energy without distorting the desired signal. In either case, it is of paramount importance to accurately quantify the achieved noise and interference reduction. Indeed, it is quite reasonable to ask, for instance, about the price that has to be paid in order to achieve total removal of the interference without distorting the target signal when using the LCMV. Besides, it is fundamental to understand the effect of the MVDR on both noise and interference. In this correspondence, we investigate the performance of the MVDR and LCMV beamformers when the interference and ambient noise coexist with the target source. We demonstrate a new relationship between both filters in which the MVDR is decomposed into the LCMV and a matched filter (MVDR solution in the absence of interference). Both components are properly weighted to achieve maximum interference-plus-noise reduction. We investigate the performance of the MVDR, LCMV, and matched filters and elaborate new closed-form expressions for their output signal-to-interference ratio (SIR) and output signal-to-noise ratio (SNR). We theoretically demonstrate the tradeoff that has to be made between noise reduction and interference rejection. In fact, the total removal of the interference may severely amplify the residual ambient noise. Conversely, totally focussing on noise reduction leads to increased level of residual interference. The proposed study is finall-
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y supported by several numerical examples. |
| Autors: Souden, M.;Benesty, J.;Affes, S.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Sep 2010, volume: 58, issue:9, pages: 4925 - 4935 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Subgradient Solution to Structured Robust Least Squares Problems |
Abstract:
A standard and established method for solving a Least Squares problem in the presence of a structured uncertainty is to assemble and solve a semidefinite programming (SDP) equivalent problem. When the problem's dimensions are high, the solution of the structured robust least squares (RLS) problem via SDP becomes an expensive task in a computational complexity sense. We propose a subgradient based solution that utilizes the MinMax structure of the problem. This algorithm is justified by Danskin's MinMax Theorem and enjoys the well-known convergence properties of the subgradient method. The complexity of the new scheme is analyzed and its efficiency is verified by simulations of a robust equalization design. |
| Autors: Salhov, M.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Sep 2010, volume: 58, issue:9, pages: 4761 - 4770 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Subharmonic Receiver in SiGe Technology for 122  GHz Sensor Applications |
Abstract:
The iterative design of an integrated subharmonic receiver for 120–127 GHz is presented. The receiver consists of a single-ended low-noise amplifier (LNA), a push-push voltage-controlled oscillator (VCO) with 1/32 divider, a polyphase filter, and a subharmonic mixer. The receiver is fabricated in SiGe:C BiCMOS technology with ${f}_{T}/{f_{max}}$ of 255$~$ GHz/315 GHz. In the first design the differential down-conversion gain of the receiver is 25 dB at 127 GHz, and the corresponding noise figure (NF) is 11 dB. The 3 dB bandwidth reaches from 125 GHz to 129 GHz. The input 1 dB compression point is at $-$ 40 dBm. The receiver draws 139 mA from a supply voltage of 3.3 V. A subsequent design demonstrates 31 dB differential gain at 122 GHz, and 11 dB NF. The 3 dB bandwidth is from 121 GHz to 124 GHz. The receiver has a NF of 8 dB for 3 GHz IF frequency due to integrated RF bandpass-filtering. It is realized by the lower NF of the LNA, and the LNA itself. |
| Autors: Schmalz, K.;Winkler, W.;Borngraber, J.;Debski, W.;Heinemann, B.;Scheytt, J. C.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Sep 2010, volume: 45, issue:9, pages: 1644 - 1656 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Systems Approach for a Stand-Alone Residential Fuel Cell Power Inverter Design |
Abstract:
Analysis of an experimentally measured daily load profile reveals that the residential power demand has a high percentage of low power duration over a day. In a stand-alone residential fuel cell power system, the power inverter designed for the peak power requirement will be operating at light loads, where its efficiency is lower, most of the time. Thus, improving the light-load efficiency will provide considerable hydrogen (energy) savings for the stand-alone residential power system. A solution to improve the power inverter efficiency at light loads is proposed. Both simulation and experimental results are given. Results show that the light-load efficiency can be improved by employing and uniquely controlling a parallel IGBT–MOSFET switch combination in a half-bridge inverter topology. It is also shown that substantial savings on hydrogen usage can be realized through the use of new inverter design in stand-alone operations. |
| Autors: Selamogullari, U. S.;Torrey, D. A.;Salon, S.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Sep 2010, volume: 25, issue:3, pages: 741 - 749 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Time-Harmonic Three-Dimensional Vector Boundary Element Model for Electromechanical Devices |
Abstract:
In present practice, the most effective way to solve the large electromagnetic (EM) boundary value problems typical in electromechanical device analysis has been with the finite element method (FEM). The sparse, symmetric, and banded structure of FEM system matrices reduces the memory requirements and facilitates several fast and efficient solution algorithms. An alternative, boundary element methods (BEM), is more computationally intensive. Recently, however, fast and efficient solver codes have been developed for BEM solutions of EM scattering problems. These, if effectively implemented in electromechanical device models, can make BEM a more feasible alternative for this purpose than previously. To generate a deeper understanding of this alternative formulation in the context of electromechanics problems, a time-harmonic 3-D vector BEM model for electromechanical devices is presented that is formulated in terms of the field variables and is capable of modeling multiple separated homogeneous regions with or without eddy currents. Extensions to electric machine modeling are given, and the model is assessed using experimental data. |
| Autors: O’Connell, T. C.;Krein, P. T.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Sep 2010, volume: 25, issue:3, pages: 606 - 618 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Unified Hopping Model for Subthreshold Current of Phase-Change Memories in Amorphous State |
Abstract:
The conduction process of phase-change-memory (PCM) devices in the amorphous high-resistance state is described by a trap-limited transport model. Based on numerical simulations of the barrier lowering in a potential landscape due to localized charged states, we propose a physically based analytical hopping model accounting for the different voltage dependence of current characteristics in the low- and high-field regimes. The analytical model is able to accurately describe, with the same set of parameters, the experimental behavior of both the temperature-dependent $I$– $V$ curves and the voltage-dependent activation energy for conduction. Comparison with experimental data is provided, demonstrating the physical consistency of the proposed model. |
| Autors: Calderoni, A.;Ferro, M.;Ielmini, D.;Fantini, P.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 1023 - 1025 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Vehicle through Which to Travel |
Abstract:
This installment looks at the work of Kyle Franklin Neuberger, who creates art based on digital imagery. |
| Autors: Singh, Gary; |
| Appeared in: IEEE Computer Graphics and Applications |
| Publication date: Sep 2010, volume: 30, issue:5, pages: 4 - 5 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Wavelet-PCA-Based Fingerprinting Scheme for Peer-to-Peer Video File Sharing |
Abstract:
In order to utilize peer-to-peer (P2P) networks in legal content distribution to benefit the legal content providers, copyright protection needs to be enhanced. In this paper, a fingerprint generation and embedding method is proposed for complex P2P file sharing networks. In this method, wavelet and principal component analysis (PCA) techniques are used for fingerprint generation. First, the wavelet technique obtains a low-frequency representation of the test image (or source file, which is assumed to be one I frame of a video with a DVD quality) and PCA finds the features of the representation. Then, a set of fingerprint matrices can be created based on a proposed algorithm. Finally, each matrix combines with the low-frequency representative to become a unique fingerprinted matrix. The fingerprinted matrix is not only much smaller than the original image in size but also contains the most important information. Without this information, the quality of the reconstructed image will be very poor. Thus, the fingerprinted file is more suitable for distribution in P2P networks, because, in the distribution stage, the uniquely fingerprinted matrix will only be dispensed by the source host and leave the rest for P2P networks to handle. On the other hand, among other frames of the same video which are not decomposed, some will be embedded with sharable fingerprints. The relationship between unique fingerprint and sharable fingerprint and the purpose of using it will be discussed in the paper. Our result indicates that the proposed fingerprint has shown strong robustness against common attacks such as Gaussian noise, median filter, and lossy compression. |
| Autors: Li, X.;Krishnan, S.;Ma, N.-W.; |
| Appeared in: IEEE Transactions on Information Forensics and Security |
| Publication date: Sep 2010, volume: 5, issue:3, pages: 365 - 373 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A-RAM Memory Cell: Concept and Operation |
Abstract:
Capacitorless single-transistor (1T) DRAM cells are envisioned for replacing the conventional DRAMs where the storage capacitor can hardly be further miniaturized. We propose a totally different 1T-DRAM cell, named A-RAM, which is compatible with SOI CMOS deep scaling. Its novelty comes from the partitioning of the transistor body into two distinct ultrathin regions separated by a thin dielectric. The holes are physically confined in the upper semibody and govern the electron current flowing into the lower semibody. The systematic simulations show that the A-RAM is attractive for low-power and embedded memory applications since it exhibits enhanced state definition, retention, scalability, and simple waveforms for word and bit lines. |
| Autors: Rodriguez, N.;Gamiz, F.;Cristoloveanu, S.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Sep 2010, volume: 31, issue:9, pages: 972 - 974 |
| Publisher: IEEE |
| Full litterature document |
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|
| » AC Performance of Polysilicon Leaky-Mode MSM Photodetectors |
Abstract:
Pulse response of polysilicon metal-semiconductor-metal (MSM) photodetectors fabricated in a standard CMOS processes is described, including demonstration of pulse full-width at half-max (FWHM) of 1.32 ns. Pulse FWHM as low as 0.81 ns has been measured, as have 10%–90% rise times of 0.39 ns. Measured detector performance is limited by laser diode modulation capabilities. An analytic expression for the time domain response in the presence of body and contact recombination is reported. |
| Autors: Pownall, R.;Kindt, J.;Nikkel, P.;Lear, K. L.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2724 - 2729 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Accelerating the Media Business with MPEG Extensible Middleware |
Abstract:
Media applications are becoming increasingly complex. They handle many data formats, run across multiple platforms, and support a wide range of functions. This article describes a standardized set of protocols and APIs that provides efficient access to individual system components, enables rapid deployment of new applications, and improves portability. |
| Autors: Timmerer, C.;Chiariglione, F.;Preda, M.;Doncel, V.R.; |
| Appeared in: IEEE Multimedia |
| Publication date: Sep 2010, volume: 17, issue:3, pages: 74 - 78 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Acceptable Use of Technology in Schools: Risks, Policies, and Promises |
Abstract:
For research on pervasive computing technologies and youth to be truly significant, we must ask why mobile devices and social media applications are much less pervasive in the classroom than in other parts of youth life. Mobile devices and social media have considerable potential for learning, from both the individual-skills and socialization perspectives. However, acceptable-use policies have limited the use of mobile devices on school campuses as a response to the risks schools face in dealing with disruptive or harmful speech. Certain perceived risks and observed problems with regard to youth online underlie educators' attitudes toward pervasive technologies in formal learning settings. Educators, researchers, and designers must work together to increase understanding of the youth experience with pervasive computing technologies and provide greater access to these systems and applications in the formal schooling context. |
| Autors: Cramer, M.;Hayes, G.; |
| Appeared in: IEEE Pervasive Computing |
| Publication date: Sep 2010, volume: 9, issue:3, pages: 37 - 44 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Access, Visualization, and Interoperability of Air Quality Remote Sensing Data Sets via the Giovanni Online Tool |
Abstract:
This paper describes the air quality data products and services available through Giovanni, a web based tool for access, visualization, and analysis of satellite remote sensing products, and also model output and surface observations relevant to global air quality. Available datasets include total column aerosol measurements from numerous satellite instruments, column ${rm NO}_{2}$ and ${rm SO}_{2}$, vertical aerosol products from CALIPSO, surface ${hbox{PM}}_{2.5}$ concentrations over the continental U.S, and speciated model Aerosol Optical Depth. Giovanni was designed to make satellite and ground-based data easier to use; it does not require separate access to or downloading of data sets, making the visualizations and analysis services accessible to both the novice and the experienced user. Giovanni air quality data products are provided on a common grid and can also be obtained in KMZ format for Google Earth visualization. This feature allows collocation of datasets to aid in analysis of pollution events and to facilitate satellite/monitor comparisons and aerosol intercomparison studies in a fraction of the time compared to traditional methods. Giovanni also supports multiple interoperability protocols which permit data sharing with other online tools, in order to enhance access to the datasets for improved air quality decision making. The Giovanni team is currently actively involved in several data networking initiatives with service oriented tools at other institutions such as DataFed. |
| Autors: Prados, A. I.;Leptoukh, G.;Lynnes, C.;Johnson, J.;Rui, H.;Chen, A.;Husar, R. B.; |
| Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Publication date: Sep 2010, volume: 3, issue:3, pages: 359 - 370 |
| Publisher: IEEE |
| Full litterature document |
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|
| » ACCNT: A Metallic-CNT-Tolerant Design Methodology for Carbon Nanotube VLSI: Analyses and Design Guidelines |
Abstract:
We present analyses for ACCNT (pronounced as “accent”), which is a solution to the metallic-nanotube problem that does not require any metallic-nanotube removal of any kind. ACCNT uses asymmetrically correlated carbon nanotubes to achieve metallic-nanotube tolerance, delivering high ON–OFF ratios while preserving current drive. We analyze the ACCNT methodology in terms of its tradeoffs and explore optimizations that may serve as future design guidelines. We also investigate circuit-level considerations and the impact of density variation on the ACCNT design. We find that ACCNT can improve the yield of a one-million transistor chip from 0% (conventional CNT design) up to 99% at a cost of $hbox{3.3}times$ area overhead if the fraction of semiconducting CNTs is improved to 99.9%. |
| Autors: Lin, A.;Zhang, J.;Patil, N.;Wei, H.;Mitra, S.;Wong, H-S.P.; |
| Appeared in: IEEE Transactions on Electron Devices |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2284 - 2295 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Achieving Ubiquity: The New Third Wave |
Abstract:
In this article, Chris Harrison, Jason Wiese, and Anind K. Dey discuss the predictions of Mark Weiser, the father of ubiquitous computing, who envisioned that we would have smart personal environments, with numerous computational devices embedded within each environment. The authors point out that, rather than this happening, what we have currently are personalized computational devices, for example, smart phones, tied to users rather than embedded in the environment. The interesting development of this observation is the crux of their article. Even though multimedia, per se, is not specifically addressed in the article, what the authors have to say is certainly relevant to our community, as smart computational devices and sensors of various sorts are certainly siblings under the skin.-William I. Grosky |
| Autors: Harrison, C.;Wiese, J.;Dey, A.K.; |
| Appeared in: IEEE Multimedia |
| Publication date: Sep 2010, volume: 17, issue:3, pages: 8 - 12 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Acknowledgement of Reviewers 2010 |
Abstract:
[No author name available] |
| Autors: Source: Microelectronic Engineering, Volume 87, Issue 12, December 2010, Pages 2642-2644 |
| Appeared in: Microelectronic Engineering |
| Publication date: Sep 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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|
| » Acoustic Simulation of a Special Switched Reluctance Drive by Means of Field–Circuit Coupling and Multiphysics Simulation |
Abstract:
The approach presented in this paper consists of an energy-based field–circuit coupling in combination with multiphysics simulation of the acoustic radiation of electrical machines. The proposed method is applied to a special switched reluctance motor with asymmetric pole geometry to improve the start-up torque. The pole shape has been optimized, subject to low torque ripple, in a previous study. The proposed approach here is used to analyze the impact of the optimization on the overall acoustic behavior. The field–circuit coupling is based on a temporary lumped-parameter model of the magnetic part incorporated into a circuit simulation based on the modified nodal analysis. The harmonic force excitation is calculated by means of stress tensor computation, and it is transformed to a mechanical mesh by mapping techniques. The structural dynamic problem is solved in the frequency domain using a finite-element modal analysis and superposition. The radiation characteristic is obtained from boundary element acoustic simulation. Simulation results of both rotor types are compared, and measurements of the drive are presented. |
| Autors: van der Giet, M.;Lange, E.;Correa, D. A. P.;Chabu, I. E.;Nabeta, S. I.;Hameyer, K.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Sep 2010, volume: 57, issue:9, pages: 2946 - 2953 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Active Noise Cancellation Without Secondary Path Identification by Using an Adaptive Genetic Algorithm |
Abstract:
This paper presents an adaptive genetic algorithm (AGA) for an active noise control (ANC) system. The conventional ANC system often implements the filtered extended least mean square (FXLMS) algorithm to update the coefficients of the linear finite-impulse response (FIR) and nonlinear Volterra filters, owing to its simplicity; meanwhile, the FXLMS algorithm may converge to local minima. In this paper, the FXLMS algorithm is replaced with an AGA to prevent the local minima problem. Additionally, the proposed AGA method does not require identifying the secondary path for the ANC, explaining why no plant measurement is necessary when designing an AGA-based ANC system. Simulation results demonstrate that the effectiveness of the proposed AGA method can suppress the nonlinear noise interference under several situations without clearly identifying the secondary path. |
| Autors: Chang, C.-Y.;Chen, D.-R.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Sep 2010, volume: 59, issue:9, pages: 2315 - 2327 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Active Shape Modeling with Electric Flows |
Abstract:
Physics-based particle systems are an effective tool for shape modeling. Also, there has been much interest in the study of shape modeling using deformable contour approaches. In this paper, we describe a new deformable model with electric flows based upon computer simulations of a number of charged particles embedded in an electrostatic system. Making use of optimized numerical techniques, the electric potential associated with the electric field in the simulated system is rapidly calculated using the finite-size particle (FSP) method. The simulation of deformation evolves based upon the vector sum of two interacting forces: one from the electric fields and the other from the image gradients. Inspired by the concept of the signed distance function associated with the entropy condition in the level set framework, we efficiently handle topological changes at the interface. In addition to automatic splitting and merging, the evolving contours enable simultaneous detection of various objects with varying intensity gradients at both interior and exterior boundaries. This electric flows approach for shape modeling allows one to connect electric properties in electrostatic equilibrium and classical active contours based upon the theory of curve evolution. Our active contours can be applied to model arbitrarily complicated objects including shapes with sharp corners and cusps, and to situations where no a priori knowledge about the object's topology and geometry is made. We demonstrate the capabilities of this new algorithm in recovering a wide variety of structures on simulated and real images in both 2D and 3D. |
| Autors: Chang, Herng-Hua;Valentino, Daniel J.;Chu, Woei-Chyn; |
| Appeared in: IEEE Transactions on Visualization and Computer Graphics |
| Publication date: Sep 2010, volume: 16, issue:5, pages: 854 - 869 |
| Publisher: IEEE |
| Full litterature document |
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|
| » Adaptive Compensation of Multimode Fiber Dispersion by Control of Launched Amplitude, Phase, and Polarization |
Abstract:
In previous work, we studied the compensation of modal dispersion in multimode fiber (MMF) using several different configurations of optical systems that can control the amplitude, phase and polarization of the launched field. In that work, we assumed knowledge of a fiber's principal modes (PMs) and their group delays (GDs), enabling us to compute the optimal settings of the optical system. In practice, however, we do not have prior knowledge of the PMs and their GDs. In this paper, for three of the configurations, we propose algorithms for setting the optical system adaptively, based upon measurements of the eye opening. We present simulations showing that in the absence of noise, the performance of the adaptive solution approaches that of the optimal solution, and characterizing the algorithms' convergence speed and tolerance to noise. We present experiments using a particular configuration and adaptive algorithm, demonstrating their effectiveness in 10-Gb/s transmission through up to 2000 m of 50-$mu$ m-core graded-index MMF. |
| Autors: Shemirani, M. B.;Wilde, J. P.;Kahn, J. M.; |
| Appeared in: Journal of Lightwave Technology |
| Publication date: Sep 2010, volume: 28, issue:18, pages: 2627 - 2639 |
| Publisher: IEEE |
| Full litterature document |
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