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Electrical and Electronics Engineering publications abstract of: 03-2010 sorted by title, page: 0 |
| » 3-D Reconstruction of Gas Clouds by Scanning Imaging IR Spectroscopy and Tomography |
Abstract:
In the case of accidents at chemical plants, during transportation of chemicals, or after terrorist attacks, hazardous compounds may be released into the atmosphere. The weather-dependent propagation of these toxic clouds can threaten population and environment. In order to apply appropriate safety measures, it is necessary for emergency response forces to detect and identify the regarding substances. In addition, it is important to determine position, dimensions, and source of the gas cloud. Moreover, it is desirable to perform the necessary measurements from a distance to minimize the threat for emergency response personnel. Imaging remote sensing by IR spectroscopy provides a method for generating (2-D) images of the cloud. Combined with an appropriate visible (video) or IR image of the scene, these images can reveal information like the dimensions and the location of the source of the cloud. Nevertheless, the distance between the system and the cloud and the dimensions of the cloud along the line of sight are not available if a single image is measured. If images of the cloud are recorded from at least two different positions at the same time, information about the position and the 3-D shape of the cloud becomes available. Therefore, a method for 3-D reconstruction of gas clouds based on imaging IR spectroscopy and tomography has been developed. The remote sensing system, the measurement setup, and the algorithm generating the 3-D structures from the images are described. The method is applied to reconstruct the exhaust gas plume of an industrial stack. |
| Autors: Rusch, P.;Harig, R.; |
| Appeared in: IEEE Sensors Journal |
| Publication date: Mar 2010, volume: 10, issue:3, pages: 599 - 603 |
| Publisher: IEEE |
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| » 5–10 Gb/s 70 mW Burst Mode AC Coupled Receiver in 90-nm CMOS |
Abstract:
A low power burst mode receiver architecture is presented which can be used for AC coupled links where low frequency signal components are attenuated by the channel. The nonlinear path comprises a hysteresis latch that recovers the missing low frequency content and a linear path that boosts the high frequency component by taking advantage of the high pass channel response. By optimally combining them, the front-end recovers NRZ signals up to 13 Gb/s burning only 26 mW in 90 nm CMOS. A low power- and area-efficient clock recovery scheme uses the linear path to injection lock an oscillator. A simple theory and simulation technique for ILO-based receivers is discussed. The clock recovery technique is verified with experimental results at 5–10 Gb/s in 90 nm CMOS consuming 70 mW and acquiring lock within 1.5 ns. |
| Autors: Hossain, M.;Chan Carusone, A.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 524 - 537 |
| Publisher: IEEE |
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| » 60-GHz Wideband Substrate-Integrated-Waveguide Slot Array Using Closely Spaced Elements for Planar Multisector Antenna |
Abstract:
A new wideband waveguide slot array is proposed for covering a wide elevation-angle range with a planar sector antenna of a multigigabit wireless LAN in the 60-GHz band. The requirement of millimeter-wave sector antennas is to realize both wide bandwidth of 11.2% and wide elevation-angle coverage with a required gain of over 10 dBi. To satisfy both the required gain and bandwidth, the important structural features of the proposed antenna are that multiple slot elements are successively arranged at an interval of the length less than one quarter guide wavelengths and that the slot length increases from the shorted waveguide end to the feed end. The operational principle of the slot array is based on multisection quarter-wavelength reflection cancellation, so the slot array can achieve the required bandwidth. Furthermore, this antenna produces a unidirectional radiation pattern by using the radiators and the reflectors, resulting in the required gain over a wide elevation-angle range. In the design, the structural parameters of the slot array are selected to meet the requirements for 60-GHz-band sector antenna. The developed substrate-integrated-waveguide (SIW) slot array achieves both the 10 dB return-loss bandwidth of 15% and the specified gain in 88–96% of the one-sector coverage range of 59–66 GHz. The effectiveness of the proposed slot array for a sector antenna is verified by the good agreement between the simulated and measured results. |
| Autors: Ohira, M.;Miura, A.;Ueba, M.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 993 - 998 |
| Publisher: IEEE |
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| » DeFer: Deferred Decision Making Enabled Fixed-Outline Floorplanning Algorithm |
Abstract:
In this paper, we present DeFer—a fast, high-quality, scalable, and nonstochastic fixed-outline floorplanning algorithm. DeFer generates a nonslicing floorplan by compacting a slicing floorplan. To find a good slicing floorplan, instead of searching through numerous slicing trees by simulated annealing as in traditional approaches, DeFer considers only one single slicing tree. However, we generalize the notion of slicing tree based on the principle of deferred decision making (DDM). When two subfloorplans are combined at each node of the generalized slicing tree, DeFer does not specify their orientations, the left-right/top-bottom order between them, and the slice line direction. DeFer even does not specify the slicing tree structure for small subfloorplan. In other words, we are deferring the decisions on these factors, which are specified arbitrarily at an early step in traditional approaches. Because of DDM, one slicing tree actually corresponds to a large number of slicing floorplan solutions, all of which are efficiently maintained in one single shape curve. With the final shape curve, it is straightforward to choose a good floorplan fitting into the fixed outline. Several techniques are also proposed to further optimize the wirelength. For both fixed-outline and classical floorplanning problems, experimental results show that DeFer achieves the best success rate, the best wirelength, the best runtime, and the best area on average compared -
with all other state-of-the-art floorplanners. |
| Autors: Yan, J. Z.;Chu, C.; |
| Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems |
| Publication date: Mar 2010, volume: 29, issue:3, pages: 367 - 381 |
| Publisher: IEEE |
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| » In Situ Observation of Compliance-Current Overshoot and Its Effect on Resistive Switching |
Abstract:
The compliance-current dependence of the resistive-switching behaviors is investigated in $hbox{TaN/Cu}_{x}hbox{O/Cu}$ memory devices with 1R architecture and 1T1R architecture, respectively. The correlation of reset current ${I}_{rm reset}$ and on-state resistance ${R}_{rm on}$ can be verified by adjusting the compliance current ${I}_{rm comp}$. Meanwhile, ${I}_{rm reset}$ and ${R}_{ rm on}$ become independent on ${I}_{rm comp}$ in the 1R architecture when ${I}_{rm comp}$ is below 1 mA. A serious compliance-current overshoot phenomenon is in situ observed in 1R-architecture device, and it remarkably affects the resistive-switching characteristics because the compliance current dominates the memory behaviors. Therefore, resistive-switching investigation based on 1T1R architecture is much more reliable. |
| Autors: Wan, H. J.;Zhou, P.;Ye, L.;Lin, Y. Y.;Tang, T. A.;Wu, H. M.;Chi, M. H.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Mar 2010, volume: 31, issue:3, pages: 246 - 248 |
| Publisher: IEEE |
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| » In Situ Poly Heater—A Reliable Tool for Performing Fast and Defined Temperature Switches on Chip |
Abstract:
In this paper, we discuss the calibration procedure and performance of the poly-heater measurement technique for device characterization and reliability issues. We put a particular emphasis on the accessible temperature range, the heating and cooling dynamics, as well as on the impact of temperature gradient between the heater, device, and thermo chuck. In this context, the poly-heater technique provides a reliable solution for fast and arbitrary temperature switches and offers the possibility to reach device temperatures that are far beyond the operating range of conventional thermo-chuck systems. |
| Autors: Aichinger, T.;Nelhiebel, M.;Einspieler, S.;Grasser, T.; |
| Appeared in: IEEE Transactions on Device and Materials Reliability |
| Publication date: Mar 2010, volume: 10, issue:1, pages: 3 - 8 |
| Publisher: IEEE |
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| » In vitro Verification of a 3-D Regenerative Neural Interface Design: Examination of Neurite Growth and Electrical Properties Within a Bifurcating Microchannel Structure |
Abstract:
Toward the development of neuroprosthesis, we propose a 3-D regenerative neural interface design for connecting with the peripheral nervous system. This approach relies on bifurcating microstructures to achieve defasciculated ingrowth patterns and, consequently, high selectivity. In vitro studies were performed to validate this design by showing that fasciculation during nerve regeneration can be influenced by providing a scaffold to guide growth appropriately. With this approach, neurites can be separated from one another and guided toward specific electrode sites to create a highly selective interface. The neurite separation characteristics were examined for smaller microchannel structures (2.5 and 5 $mu{hbox{m}}$ wide) and larger microchannels (10 and 20 $mu{hbox{m}}$ wide), with smaller microchannels shown to be statistically more effective at initiating separation. Electrodes incorporated at different locations within the microchannels allowed for the recording and tracking of action potential propagation. Microchannel size was also found to play an important role in this regard, with smaller microchannels amplifying the recordable extracellular signal; a twofold increase in the signal to noise ratio was found for 5 $mu{hbox{m}}$ wide microchannels. |
| Autors: Wieringa, P. A.;Wiertz, R. W. F.;de Weerd, E. L.;Rutten, W. L. C.; |
| Appeared in: Proceedings of the IEEE |
| Publication date: Mar 2010, volume: 98, issue:3, pages: 389 - 397 |
| Publisher: IEEE |
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| » In Vivo Supervised Analysis of Stent Reendothelialization From Optical Coherence Tomography |
Abstract:
The aim of this study is to interactively assess reendothelialization of stents at an accuracy of down to a few micrometer by analyzing endovascular optical coherence tomography (OCT) sequences. Vessel wall and stent struts are automatically detected by using morphological, gradient, and symmetry operators coupled with active contour models; alerts are issued to ask for user supervision over some extreme irregular geometries caused by thrombotic lesions or dissections. A complete distance map is then computed from sparse distances measured between wall and struts. Missing values are interpolated by thin-plate spline (TPS) functions. Accuracy and robustness are increased by taking into account the inhomogeneity of data points and integrating in the same framework orthogonalized forward selection of support points, optimal selection of regularization parameters by generalized cross-validation, and rejection of detection outliers. Validation is performed on simulated data, phantom acquisitions and 11 typical in vivo OCT sequences. The comparison against manual expert measurements demonstrates a bias of the order of OCT resolution (less than 10 $mu$m) and a standard deviation of the order of the strut width (less than 150 $mu$m ). |
| Autors: Kauffmann, C.;Motreff, P.;Sarry, L.; |
| Appeared in: IEEE Transactions on Medical Imaging |
| Publication date: Mar 2010, volume: 29, issue:3, pages: 807 - 818 |
| Publisher: IEEE |
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| » In Vivo Validation of a Hybrid Tracking System for Navigation of an Ultrathin Bronchoscope Within Peripheral Airways |
Abstract:
Transbronchial biopsy of peripheral lung nodules is hindered by the inability to access lesions endoluminally due to the large diameter of conventional bronchoscopes. An ultrathin scanning fiber bronchoscope has recently been developed to advance image-guided biopsy several branching generations deeper into the peripheral airways. However, navigating a potentially complex 3-D path to the region of interest presents a challenge to the bronchoscopist. An accompanying guidance system has also been developed to track the bronchoscope through the airways, and display its position and intended path on a virtual display. Intraoperative localization of the bronchoscope was achieved by combining electromagnetic tracking (EMT) and image-based tracking (IBT). An error-state Kalman filter was used to model the disagreement between the two tracking sources. The positional tracking error was reduced from 14.22 and 14.92 mm by independent EMT and IBT, respectively, to 6.74 mm using the hybrid approach. Hybrid tracking of the scope orientation and respiratory motion compensation further improved tracking accuracy and stability, resulting in an average tracking error of 3.33 mm and 10.01 $^circ$. |
| Autors: Soper*, T. D.;Haynor, D. R.;Glenny, R. W.;Seibel, E. J.; |
| Appeared in: IEEE Transactions on Biomedical Engineering |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 736 - 745 |
| Publisher: IEEE |
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» A 0.02-mm  9-Bit 50-MS/s Cyclic ADC in 90-nm Digital CMOS Technology |
Abstract:
A 9-bit cyclic ADC employs a track-and-evaluation technique for enhancing the speed of residue evaluation. The proposed multiply-by-two circuit has a shorter evaluation time than the conventional design due to the application of a partial positive feedback topology. The residue evaluation and sampling phases are merged to reduce the conversion latency. Hence, only four clock cycles are required to perform the 9-bit conversion. The proposed 0.02-${hbox {mm}}^{2}$ ADC has been fabricated in 90-nm digital CMOS technology. It operates at 50 MS/s and achieves an SNDR of 50.5 dB with a power consumption of 6.9 mW from a 1.0-V supply. |
| Autors: Huang, Y.-C.;Lee, T.-C.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 610 - 619 |
| Publisher: IEEE |
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| » A 0.35?m CMOS divide-by-2 quadrature injection-locked frequency divider based on voltage-current feedback topology |
Abstract:
This paper presents a new divide-by-2 quadrature injection-locked frequency divider (QILFD). The QILFD consists of a new transformer-coupled quadrature voltage controlled oscillator (QVCO) with the voltage-current feedback technique and two NMOS switches, which are in parallel with the QVCO resonators for signal injection. The proposed CMOS QILFD has been implemented with the TSMC 0.35?m CMOS technology and the core power consumption is 16.52mW at the supply voltage of 2.2V. The free-running frequency of the QILFD is tunable from 2.85GHz to 3.07GHz. At the input power of 0dBm, the divide-by-2 operation range is from 5.48GHz to 6.48GHz. The phase deviation of... |
| Autors: Sheng-Lyang, Jang , Cheng-Chen, Liu , Ren-Kai, Yang , Chih-Chieh, Shih , Chia-Wei, Chang , ... |
| Appeared in: Microelectronics Reliability |
| Publication date: Mar 2010 |
| Publisher: Elsevier B.V. |
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| » A 0.6-V Zero-IF/Low-IF Receiver With Integrated Fractional-N Synthesizer for 2.4-GHz ISM-Band Applications |
Abstract:
Supply voltage reduction with process scaling has made the design of analog, RF and mixed mode circuits increasingly difficult. In this paper, we present the design of an ultra-low voltage, low power and highly integrated dual-mode receiver for 2.4-GHz ISM-band applications. The receiver operates reliably from 0.55–0.65 V and is compatible with commercial standards such as Bluetooth and ZigBee. We discuss the design challenges at low voltage supplies such as limited f$_{rm T}$ for transistors and higher nonlinearities due to limited available signal swing, and present the architectural and circuit level design techniques used to overcome these challenges. The highly integrated receiver prototype chip contains RF front-end circuits, analog baseband circuits and the RF frequency synthesizer and was fabricated in a standard digital 90-nm CMOS process; it achieves a gain of 67 dB, noise figure of 16 dB, ${hbox{IIP}}_{3}$ of $-$10.5 dBm, synthesizer phase noise of $-$ 127 dBc/Hz at 3-MHz offset, consumes 32.5 mW from 0.6 V and occupies an active area of 1.7 ${hbox {mm}}^{2}$. |
| Autors: Balankutty, A.;Yu, S.-Y.;Feng, Y.;Kinget, P. R.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 538 - 553 |
| Publisher: IEEE |
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| » A 116 fps/74 mW Heterogeneous 3D-Media Processor for 3-D Display Applications |
Abstract:
In this paper, a heterogeneous 3D-media processor is presented, which supports all 3-D display applications by combining a 3-D display IP with a 3-D graphics IP and a stereo video decoder. For mobile environments, adaptive power management scheme is proposed, which saves power consumption up to 186 mW by turning off idle functional blocks based on a target application, a target performance, and the run-time ratio between different IPs. As a result, the minimum power consumption of the processor is only 15 mW, while the overall power consumption is 201 mW. As well as the reduction of power consumption, this work shows impressive performance improvement. The proposed fast modulo operators and adopted division-free algorithm reduces the critical latencies of 3-D display image processing. The proposed fast datapath with parallel architecture increase synthesis rate up to 116 fps which is 17 times faster than a previous work. In addition, reordered operation sequence fixes memory bandwidth regardless of the number of images to be produced. In the 3-D graphics IP and the decoding IP, redundant datapath are merged using an IEEE 754 compliant floating-point vector unit to save both chip area and power consumption, which even reduces the critical latency by 30%. |
| Autors: Kim, S.-H.;Kim, H.-Y.;Kim, Y.-J.;Chung, K.;Kim, D.;Kim, L.-S.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 652 - 667 |
| Publisher: IEEE |
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| » A 12 bit 50 MS/s CMOS Nyquist A/D Converter With a Fully Differential Class-AB Switched Op-Amp |
Abstract:
A 12 bit 50 MS/s 1.8 V pipelined CMOS analog-to-digital converter (ADC) based on a fully differential class-AB switched operational amplifier achieves low power consumption with a differential input voltage of 2.4 Vp-p. A global-loop dynamic common-mode feedback circuit enables fully differential class-AB operation with dynamic current switching for power reduction. The prototype ADC shows a peak signal-to-noise-and-distortion ratio of 64.0 dB and a peak spurious-free dynamic range of 76.6 dB for a 31 MHz input signal at 50 MS/s while the measured differential and integral nonlinearities are within $pm $0.26 LSB and $pm $0.72 LSB, respectively. The prototype ADC in a 0.18 $mu{hbox {m}}$ 1P6M CMOS process consumes 18.4 mW at 50 MS/s and 1.8 V occupying an active die area of 0.26 ${hbox {mm}}^{2}$. |
| Autors: Kim, Y.-J.;Choi, H.-C.;Ahn, G.-C.;Lee, S.-H.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 620 - 628 |
| Publisher: IEEE |
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| » A 5-bit 3.2-GS/s Flash ADC With a Digital Offset Calibration Scheme |
Abstract:
In high-speed Flash analog-to-digital converters (ADCs), preamplifiers are often placed in front of a comparator to reduce metastability errors and enhance comparison speed. The accuracy of a Flash ADC is mainly limited by the random offsets of preamplifiers and comparators. This paper presents a 5-b Flash ADC with a digital random offset calibration scheme. For calibration, programmable resistive devices are used as the loading devices of the second-stage preamplifiers. By adjusting the calibration resistors, the input-referred offset voltage of each comparator is reduced to be less than 1/2 LSB. Fabricated in a 0.13-${rm mu}hbox{m}$ CMOS process, experimental results show that the ADC consumes 120 mW from a 1.2-V supply and occupies a 0.18- $hbox{mm}^{2}$ active area. After calibration, the peak differential non-linearity (DNL) and integral non-linearity (INL) are 0.24 and 0.39 LSB, respectively. At 3.2-GS/s operation, the effective number of bits is 4.54 b, and the effective resolution bandwidth is 600 MHz. This ADC achieves figures of merit of 3.07 and 4.30 pJ/conversion-step at 2 and 3.2 GS/s, respectively. |
| Autors: Lin, Y.-Z.;Lin, C.-W.;Chang, S.-J.; |
| Appeared in: IEEE Transactions on Very Large Scale Integration Systems |
| Publication date: Mar 2010, volume: 18, issue:3, pages: 509 - 513 |
| Publisher: IEEE |
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| » A 58–65 GHz Neutralized CMOS Power Amplifier With PAE Above 10% at 1-V Supply |
Abstract:
A 60-GHz band, three-stage pseudo-differential power amplifier (PA) is implemented with input and output baluns on-chip. Each stage consists of a neutralized common-source amplifier pair. Neutralization mitigates the intrinsic gate-drain feedback of each transistor for increased power gain and reverse isolation. Shielded transformers couple the gain stages and allow low supply voltage operation. Fabricated in a 65-nm bulk CMOS process, the measured small-signal gain of the 0.13$,times,$ 0.41 mm$^{2}$ PA is 16 dB at 60 GHz with 3-dB bandwidth more than 8.5 GHz, while consuming 50 mW from a 1-V supply. Reverse isolation is better than 42 dB from 55 to 65$~$GHz. Maximum saturated output power is 11.5 dBm with a peak PAE of 15.2% measured at 62$~$GHz; from 58 to 65$~$GHz, the measured PAE is above 10%. |
| Autors: Chan, W. L.;Long, J. R.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 554 - 564 |
| Publisher: IEEE |
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| » A 7.1 mW, 10 GHz All Digital Frequency Synthesizer With Dynamically Reconfigured Digital Loop Filter in 90 nm CMOS Technology |
Abstract:
A 10 GHz all digital frequency synthesizer (ADPLL) with dynamic digital loop filter is presented. Governed by a proposed locking process monitor (LPM), the digital loop filter is automatically reconfigured during the frequency acquisition and phase tracking process. The loop bandwidth is also self-adjusted during the locking process so as to achieve fast lock and low noise simultaneously. A skew-compensated phase accumulator is proposed for high speed operation, which preserves the advantages of low power dissipation while eliminating the accumulated timing skew issue. With less than 7 $mu$s locking time, the measured rms jitter from a 9.92 GHz carrier is about 0.9 ps. The ADPLL core consumes 7.1$~$mW from a 1 V supply, and the digital I/O cells drains 2.7 mW from a 3.3 V supply for chip measurement. Implemented in a 90$~$ nm CMOS technology, the core area is only 0.352 mm $^{2}$. |
| Autors: Yang, S.-Y.;Chen, W.-Z.;Lu, T.-Y.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 578 - 586 |
| Publisher: IEEE |
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| » A closed core micro fluxgate sensor with cascaded planar FeNi ring cores |
Abstract:
In this paper, we present a new microfabricated fluxgate sensor structure using cascaded planar rings as the ferromagnetic core. The planar ring structures provide a closed magnetic excitation loop enabling uniform core saturation with relatively small excitation magnetic field. The magnetic excitation is provided with a rod passing through the ring cores. Planar coils placed under the edges of the core are used as sensing elements. By using this structure, fluxgate sensors having a closed core configuration are realized with a developed microfabrication process in a very small area (<0.1mm2) with reduced number of via connections. The ferromagnetic rings are... |
| Autors: O., Zorlu , P., Kejik , W., Teppan |
| Appeared in: Sensors and Actuators A: Physical |
| Publication date: Mar 2010 |
| Publisher: Elsevier B.V. |
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| » A Compact Wideband CMOS Low Noise Amplifier With Gain Flatness Enhancement |
Abstract:
This paper presents a compact 0.18-$mu$m CMOS wideband gain-flattened low noise amplifier (LNA). The low noise characteristic of the LNA is achieved by the noise canceling technique and the gain flatness is enhanced by the gate-inductive gain-peaking technique. In addition to extending flat-gain bandwidth, the proposed gain-peaking technique results in better wideband noise canceling and quick gain roll-off outside the desired signal band to reject interference. Without using any passive inductor, the core size of the fully-integrated CMOS LNA circuit is only 145 $mu$ m$,times,$ 247 $mu$ m. The measured gain and noise figure of the CMOS LNA are 16.4 dB and 2.1 dB, respectively. The gain variation of the LNA is ${pm} $0.4 dB from 50 to 900 MHz. Operated at 1.8 V, the chip consumes 14.4 mW of power. |
| Autors: Yu, Y.-H.;Yang, Y.-S.;Chen, Y.-J. E.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 502 - 509 |
| Publisher: IEEE |
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| » A compact, transportable, microchip-based system for high repetition rate production of Bose–Einstein condensates |
Abstract:
We present a compact, transportable system that produces Bose–Einstein condensates near the surface of an integrated atom microchip. The system occupies a volume of 0.4 m3, operates at a repetition rate as high as 0.3 Hz, and consumes an average power of 525 W. Evaporative cooling in a chip trap with trap frequencies of several kilohertz leads to nearly pure condensates containing 1.9×104 87Rb atoms. Partial condensates are observed at a temperature of 1.58(8) μK, close to the theoretical transition temperature of 1.1 μK. |
| Autors: Farkas, Daniel M.;Hudek, Kai M.;Salim, Evan A.;Segal, Stephen R.;Squires, Matthew B.;Anderson, Dana Z.; |
| Appeared in: Applied Physics Letters |
| Publication date: Mar 2010, volume: 96, issue:9, pages: 093102 - 093102-3 |
| Publisher: IEEE |
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| » A Comparative Evaluation of Techniques for Single-Frame Discrimination of Nonstationary Sinusoids |
Abstract:
Many spectral analysis and modification techniques require the separation of sinusoidal from nonsinusoidal signal components of a Fourier spectrum. Techniques exist for the estimation of the parameters of nonstationary sinusoids, and for discriminating these from other components, within a single Fourier frame. We present a comparative study of five methods for sinusoidal discrimination, considering their effectiveness and their computational cost. |
| Autors: Wells, J.J.;Murphy, D.T.; |
| Appeared in: IEEE Transactions on Audio, Speech, and Language Processing |
| Publication date: Mar 2010, volume: 18, issue:3, pages: 498 - 508 |
| Publisher: IEEE |
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| » A comparative study of two techniques for improving power-handling capability of CMOS T/R switches |
Abstract:
This article proposes an asymmetric topology for transmit/receive (T/R) switches and more importantly presents a comparative study of both LC-tuned and resistive body-floating techniques for improving the power-handling capability of the T/R switches in the same 0.18-[mu]m triple-well CMOS. It is shown from simulations and measurements that the switches adopting either technique achieve comparable performances. For instance, the switch employing the LC-tuned body-floating technique exhibits insertion loss of 1.5 dB, isolation of 23.5 dB, and power-handling capability of 22.5 dBm at 5.2 GHz, whereas the switch using the resistive body-floating technique exhibits insertion loss of 1.3 dB, isolation of 24 dB, and power-handling capability of 22.2 dBm, respectively. Therefore, one can conclude that the asymmetric topology with the resistive body-floating technique is more suitable for designing T/R switches for wireless local area network applications as it consumes smaller silicon area. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. |
| Autors: Jin He, Yue Ping Zhang, Kiat Seng Yeo, Wei Meng Lim |
| Appeared in: International Journal of RF and Microwave Computer-Aided Engineering |
| Publication date: Mar 2010 |
| Publisher: Wiley InterScience |
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| » A Comparison of a Wide-Slot and a Stacked Patch Antenna for the Purpose of Breast Cancer Detection |
Abstract:
A wide-slot UWB antenna is presented for intended use in the detection scheme being developed at the University of Bristol, based on the principle of synthetically focused UWB radar using a fully populated static array. The antenna's measured and simulated, input and radiation characteristics are presented and compared to an existing, stacked patch antenna that has been designed for the same purpose. The results of this study show that the wide-slot antenna has excellent performance across the required frequency range. Compared to the stacked-patch antenna used in our previous array, the wide-slot antenna can be 3 times smaller (in terms of front surface). The compact nature of the slot antenna means that the detection array can be densely populated. Additionally, this new antenna offers better radiation coverage of the breast. For angles up to 60$^{circ}$ away from bore-sight radiated pulses are almost identical (fidelity $>$95%), whereas for the patch antenna fidelity falls to 58% at the angular extremes. This uniform radiation into the breast should result in focused images with low levels of clutter. |
| Autors: Gibbins, D.;Klemm, M.;Craddock, I. J.;Leendertz, J. A.;Preece, A.;Benjamin, R.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 665 - 674 |
| Publisher: IEEE |
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| » A Comparison of Optimization Algorithms for Biological Neural Network Identification |
Abstract:
Recently, the identification of biological neural networks has been reformulated as an optimization problem based on a framework of adaptive synchronization. In this paper, four different optimization algorithms, including genetic algorithm, jumping gene genetic algorithm (JGGA), tabu search, and simulated annealing, have been applied for this optimization problem. Based on the simulation results, their performances are compared, and it is concluded that JGGA can outperform the other three methods in term of minimizing the synchronization and parameter estimation errors. |
| Autors: Yin, J. J.;Tang, W. K. S.;Man, K. F.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 1127 - 1131 |
| Publisher: IEEE |
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| » A Complex Generalized Gaussian Distribution— Characterization, Generation, and Estimation |
Abstract:
The generalized Gaussian distribution (GGD) provides a flexible and suitable tool for data modeling and simulation, however the characterization of the complex-valued GGD, in particular generation of samples from a complex GGD have not been well defined in the literature. In this correspondence, we provide a thorough presentation of the complex-valued GGD by: (i) constructing the probability density function (pdf); (ii) defining a procedure for generating random numbers from the complex-valued GGD; and (iii) implementing a maximum likelihood estimation (MLE) procedure for the shape and covariance parameters in the complex domain. We quantify the performance of the MLE with simulations and actual radar data. |
| Autors: Novey, M.;Adal, T.;Roy, A.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 1427 - 1433 |
| Publisher: IEEE |
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| » A Composite PN-Correlation Based Synchronizer for TDS-OFDM Receiver |
Abstract:
In this paper, we presents a novel synchronizer dealing with carrier frequency offset (CFO), sampling frequency offset (SFO), as well as frame timing offset (FTO) in TDS-OFDM receiver. The proposed schemes are based on tracking the output waveform of a composite PN-correlator (CPC), which provides sufficient correlative gains to detect its peaks even in the presence of large CFOs. From the correlation peaks, we can extract useful information for estimating the synchronization offsets. CFO is recovered by a multi-stage CPC scheme, of which the parameters are adjustable for meeting the system's demands on the tracking range and accuracy. According to the inter-frame variations of correlation waveform, we estimate SFO for a large scale and correct SFO through an interpolator. Meanwhile, frame timing is investigated in this paper, and the analysis indicates a very fast and robust timing scheme is possible for TDS-OFDM receiver. The developed synchronizer is quite robust against a large CFO even in very adverse fading channels, and it is shown by computer simulation that the residual synchronization error has little effect on the performance of TDS-OFDM receiver. |
| Autors: Liu, G.;Zhidkov, S. V.; |
| Appeared in: IEEE Transactions on Broadcasting |
| Publication date: Mar 2010, volume: 56, issue:1, pages: 77 - 85 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Comprehensive Mixed-Mode Time-Domain Load- and Source-Pull Measurement System |
Abstract:
We present a novel test set devised for nonlinear balanced device characterization using load-pull techniques. The system is capable of measuring the voltage and current waveforms at the calibration reference planes while independently tuning the device under test (DUT) source and load differential- and common-mode terminations. The test set is designed to address present and future large-signal multiport measurement needs, easing the characterization task while developing new multiport active devices. |
| Autors: Teppati, V.;Ferrero, A.;Garelli, M.;Bonino, S.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 616 - 622 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Computationally Efficient Generalized Poisson Solution for Independent Double-Gate Transistors |
Abstract:
Previous techniques used for solving the 1-D Poisson equation (PE) rigorously for long-channel asymmetric and independent double-gate (IDG) transistors result in potential models that involve multiple intercoupled implicit equations. As these equations need to be solved self-consistently, such potential models are clearly inefficient for compact modeling. This paper reports a different rigorous technique for solving the same PE by which one can obtain the potential profile of a generalized IDG transistor that involves a single implicit equation. The proposed Poisson solution is shown to be computationally more efficient for circuit simulation than the previous solutions. |
| Autors: Sahoo, A.;Thakur, P. K.;Mahapatra, S.; |
| Appeared in: IEEE Transactions on Electron Devices |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 632 - 636 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Cooperative Cellular and Broadcast Conditional Access System for Pay-TV Systems |
Abstract:
The lack of interoperability between Pay-TV service providers and a horizontally integrated business transaction model have compromised the competition in the Pay-TV market. In addition, the lack of interactivity with customers has resulted in high churn rate and improper security measures have contributed into considerable business loss. These issues are the main cause of high operational costs and subscription fees in the Pay-TV systems. As a result, this paper presents the Mobile Conditional Access System (MICAS) as an end-to-end access control solution for Pay-TV systems. It incorporates the mobile and broadcasting systems and provides a platform whereby service providers can effectively interact with their customers, personalize their services and adopt appropriate security measurements. This would result in the decrease of operating expenses and increase of customers' satisfaction in the system. The paper provides an overview of state-of-the-art conditional access solutions followed by detailed description of design, reference model implementation and analysis of possible MICAS security architectures. |
| Autors: Shirazi, H.;Cosmas, J.;Cutts, D.; |
| Appeared in: IEEE Transactions on Broadcasting |
| Publication date: Mar 2010, volume: 56, issue:1, pages: 44 - 57 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Coupled Level Set Framework for Bladder Wall Segmentation With Application to MR Cystography |
Abstract:
In this paper, we propose a coupled level set (LS) framework for segmentation of bladder wall using ${rm T}_{1}$-weighted magnetic resonance (MR) images with clinical applications to virtual cystoscopy (i.e., MR cystography). The framework uses two collaborative LS functions and a regional adaptive clustering algorithm to delineate the bladder wall for the wall thickness measurement on a voxel-by-voxel basis. It is significantly different from most of the pre-existing bladder segmentation work in four aspects. First of all, while most previous work only segments the inner border of the wall or at most manually segments the outer border, our framework extracts both the inner and outer borders automatically except that the initial seed point is given by manual selection. Secondly, it is adaptive to ${rm T}_{1}$-weighted images with decreased intensities in urine, as opposed to enhanced intensities in ${rm T}_{2}$-weighted scenario and computed tomography. Thirdly, by considering the image global intensity distribution and local intensity contrast, the defined image energy function in the framework is more immune to inhomogeneity effect, motion artifacts and image noise. Finally, the bladder wall thickness is measured by the length of integral path between the two borders which mimic the electric field line between two iso-potential surfaces. The framework was tested on six datasets with comparison to the well-known Chan-Vese (C-V) LS model. Five experts blindly scored the segmented inner and outer borders of the presented framework and the C-V model. The scores demonstrated statistically the improvement in detecting the inner and outer borders. |
| Autors: Duan, C.;Liang, Z.;Bao, S.;Zhu, H.;Wang, S.;Zhang, G.;Chen, J. J.;Lu, H.; |
| Appeared in: IEEE Transactions on Medical Imaging |
| Publication date: Mar 2010, volume: 29, issue:3, pages: 903 - 915 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Current Reuse Quadrature GPS Receiver in 0.13  m CMOS |
Abstract:
A fully-integrated quadrature low-IF L1-band GPS receiver consumes only 6.4 mW in 0.13 $mu$ m CMOS. The RF front-end features a gate-modulated quadrature VCO for low phase noise and accurate quadrature phase signal generation. It merges the LNA, quadrature mixer, and quadrature VCO in a single current-reuse stacked topology that provides a conversion gain 42.5 dB with a power consumption of 1 mW. A continuous-time (CT) quadrature bandpass sigma-delta analog-to-digital converter (ADC) provides inherent anti-alias filtering, which simplifies the overall system. The second-order CT $Sigma Delta$ ADC achieves 65 dB dynamic range and dissipates only 4.2 mW using resistor DAC feedback. The receiver exhibits an NF of 6.5 dB and an IIP3 of ${-}$ 30 dBm; the PLL phase noise is ${-}$110 dBc/Hz @$~$1 $~$MHz frequency offset with quadrature error less than 1$^{circ}$. |
| Autors: Cheng, K.-W.;Natarajan, K.;Allstot, D. J.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 510 - 523 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A digitally compensated 1.5 GHz CMOS/FBAR frequency reference |
Abstract:
A temperature-compensated 1.5 GHz film bulk acoustic wave resonator (FBAR)-based frequency reference implemented in a 0.35 μm CMOS process is presented. The ultra-small form factor (0.79 mm ÿ 1.72 mm) and low power dissipation (515 μA with 2 V supply) of a compensated FBAR oscillator present a promising alternative for the replacement of quartz crystal frequency references. The measured post-compensation frequency drift over a 0¿100°C temperature range is <±10 ppm. The measured oscillator phase noise is ¿133 dBc/ Hz at 100 kHz offset from the 1.5 GHz carrier. |
| Autors: Rai, S.;Su, Y.;Pang, W.;Ruby, R.;Otis, B.; |
| Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 552 - 561 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Direct Measurement Method of Frequency Responses of the Smart Power IC |
Abstract:
Smart power ICs are widely used in universal input power supplies. This paper presents a detailed analysis and scheme design for real-time small-signal modeling method for smart power IC. First, in this method, the switching duty cycle is converted into a voltage output signal based on the operational characteristics of the power IC. The power IC's frequency response is then obtained by measuring the duty cycle output signal and the power IC's control input signal. The modeling system is referred to as sampling the duty cycle of the power IC with a zero-order hold output. Using least-square identification, the smart power IC's dynamic model and transfer function are synthesized from the measurement data. The results of the modeling experiment are discussed, and practical guidelines and error amplifier (EA) design examples are presented for both continuous and discontinuous conduction modes (CCM and DCM). The effectiveness and practicality are verified through experiments. |
| Autors: Hai Xu;Hee-Jun Kim;Hoon Kim; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 682 - 686 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Discrete Matlab–Simulink Flickermeter Model for Power Quality Studies |
Abstract:
A discrete model of the IEC 61000-4-15 flickermeter is developed for use with the Matlab-Simulink simulation software package. The discrete model is a faithful reproduction of a flickermeter defined by the IEC Standard; it duplicates the functional blocks described by the standard and operates in the same way as the standardized instrument to assure complete fidelity of results. The model is intended to be used within larger simulations that contain discrete model blocks, either alone or in combination with the Simulink SimPowerSystems blockset, to provide direct quantification of flicker. The model is fully developed, and all model parameters are provided for use with 60-Hz systems. A discrete calibrator is described that duplicates the test waveforms described by the IEC Standard. |
| Autors: White, L.W.;Bhattacharya, S.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 527 - 533 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Doubly Weighted Approach for Appearance-Based Subspace Learning Methods |
Abstract:
We propose in this paper a doubly weighted subspace learning approach for face representation and recognition. Motivated by the fact that some face samples and parts are more effectual in characterizing and recognizing faces, we construct two weighting matrices based on pairwise similarity of face samples within a same class and discriminant score of each pixel within a face sample to duly emphasize both the between-sample and within-sample features. We then incorporate these two weighting matrices into three popular subspace learning methods, namely principal component analysis, linear discriminant analysis, and nonnegative matrix factorization, to obtain the discriminative features of faces for recognition. Moreover, the proposed doubly weighted technique can be readily extended to other newly proposed subspace learning algorithms to improve their performance. Experimental results show that the proposed approach can effectively enhance the discriminant power of the extracted face features and outperform existing, nonweighted subspace learning algorithms. The performance gain is even more apparent for cases with imbalanced training samples. |
| Autors: Lu, J.;Tan, Y.-P.; |
| Appeared in: IEEE Transactions on Information Forensics and Security |
| Publication date: Mar 2010, volume: 5, issue:1, pages: 71 - 81 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Fast Nonparametric Noncausal MRF-Based Texture Synthesis Scheme Using a Novel FKDE Algorithm |
Abstract:
In this paper, a new algorithm is proposed for fast kernel density estimation (FKDE), based on principal direction divisive partitioning (PDDP) of the data space. A new framework is also developed to apply FKDE algorithms (both proposed and existing), within nonparametric noncausal Markov random field (NNMRF) based texture synthesis algorithm. The goal of the proposed FKDE algorithm is to use the finite support property of kernels for fast estimation of density. It has been shown that hyperplane boundaries for partitioning the data space and principal component vectors of the data space are two requirements for efficient FKDE. The proposed algorithm is compared with the earlier algorithms, with a number of high-dimensional data sets. The error and time complexity analysis, proves the efficiency of the proposed FKDE algorithm compared to the earlier algorithms. Due to the local simulated annealing, direct incorporation of the FKDE algorithms within the NNMRF-based texture synthesis algorithm, is not possible. This work proposes a new methodology to incorporate the effect of local simulated annealing within the FKDE framework. Afterward, the developed texture synthesis algorithms have been tested with a number of different natural textures, taken from a standard database. The comparison in terms of visual similarity and time complexity, between the proposed FKDE based texture synthesis algorithm with the earlier algorithms, show the efficiency. |
| Autors: Sinha, A.;Gupta, S.; |
| Appeared in: IEEE Transactions on Image Processing |
| Publication date: Mar 2010, volume: 19, issue:3, pages: 561 - 572 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Feasible Solution to the Beam-Angle-Optimization Problem in Radiotherapy Planning With a DNA-Based Genetic Algorithm |
Abstract:
Intensity-modulated radiotherapy (IMRT) is now becoming a powerful clinical technique to improve the therapeutic radio for cancer treatment. It has been demonstrated that selection of suitable beam angles is quite valuable for most of the treatment plans, especially for the complicated tumor cases and when limited number of beams is used. However, beam-angle optimization (BAO) remains a challenging inverse problem mainly due to the huge computation time. This paper introduced a DNA genetic algorithm (DNA-GA) to solve the BAO problem aiming to improve the optimization efficiency. A feasible mapping was constructed between the universal DNA-GA algorithm and the specified engineering problem of BAO. Specifically, a triplet code was used to represent a beam angle, and the angles of several beams in a plan composed a DNA individual. A bit-mutation strategy was designed to set different segments in DNA individuals with different mutation probabilities; and also, the dynamic probability of structure mutation operations was designed to further improve the evolutionary process. The results on simulated and clinical cases showed that DNA-GA is feasible and effective for the BAO problem in IMRT planning, and to some extent, is faster to obtain the optimized results than GA. |
| Autors: Li*, Y.;Lei, J.; |
| Appeared in: IEEE Transactions on Biomedical Engineering |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 499 - 508 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Ferroelectric-Capacitor-Based Approach to Quasistatic Electric Field Sensing |
Abstract:
A new sensor for quasistatic electric field (E-field) measurements based on a ferroelectric capacitor (which acts as a nonlinear active dynamic element) is discussed in this paper. The device was theoretically modeled and experimentally characterized, and the data that were gathered were used to refine the model parameters. The E-field sensing strategy is based on the exploitation of a mechanism to convert the external target E-field into a perturbation on the polarization state of a ferroelectric material: a detailed analytical description of this process is given together with its experimental validation. Optimal results have been obtained with a driving (i.e., reference) signal of 10 V at 100 Hz, which was used to polarize the device. The noise floor of the device has been evaluated through an analysis of the power spectral density, which yields a value of 0.4 (V/m)/Hz1/2. The hysteretic capacitor in this paper is the cornerstone of an innovative system for detecting weak E-fields (assumed to be dc throughout this paper, although it can also be applied to detect time-periodic E-fields) through the exploitation of the nonlinear behavior of a coupled oscillator system wherein the active (nonlinear) elements are the ferroelectric capacitors. Our results cover the basic building blocks that were necessary for the optimal realization of this coupled circuit. |
| Autors: Ando, B.;Baglio, S.;Bulsara, A.R.;Marletta, V.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 641 - 652 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Ferrofluidic Inclinometer in the Resonant Configuration |
Abstract:
In this paper, an innovative inclinometer exploiting ferrofluids is presented. The device consists of a glass pipe filled with deionized water and a drop of ferrofluid, a coil generating a retaining force on the ferrofluidic drop, a couple of sensing coils detecting the ferrofluidic mass position, and two exciter coils moving the ferrofluidic drop back and forth inside the water at the resonance frequency of the whole system. The device exhibits an intrinsic robustness against inertial shocks. The resonant operation mode represents the main novelty with respect to previous realizations of the ferrofluidic inclinometer presented by the authors. This strategy allows for improving the performances of the inclinometer also in terms of mechanical sensitivity. This paper will focus on the design and experimental characterization of the resonant inclinometer, showing improvements achieved by the resonant configuration with respect to the previous “static implementation” without the exciter coils. |
| Autors: Ando, B.;Ascia, A.;Baglio, S.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 558 - 564 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Finite Edge GTD Analysis of the H-Plane Horn Radiation Pattern |
Abstract:
The earlier geometrical theory of diffraction (GTD) approach to the H-plane horn radiation problem is reconsidered with spherical source excitation. Corner diffraction terms are included to provide a GTD model for the finiteness of the horn edges. A new heuristic corner slope diffraction (CSD) coefficient for a finite edge in a conducting plane is presented. The H-plane horn pattern, obtained with the addition of the corner diffraction and the new CSD terms to the earlier infinite edge GTD approach, is found to be in better agreement with measured results compared to earlier GTD formulations. |
| Autors: Ali, M.;Sanyal, S.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 969 - 973 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Flux-Based Expression of Induction Machine Magnetizing Inductance |
Abstract:
Tending toward the adaptive modeling of main flux saturation in induction machine, this brief discloses the induction machine magnetizing inductance as an expression in terms of only d –q axis winding flux linkages. It will be shown that such an expression considerably facilitates the inclusion of main flux saturation effects in internal structure of the well-established winding flux linkage state-space model. The derivation procedure will be carried out without altering the structural equations of the generalized d– q axis mathematical model of the induction machine. |
| Autors: Lupsa-Tataru, L.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 268 - 270 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Form-Wound Induction Machine Model for the Study of Three-Phase Surge Propagation |
Abstract:
A three-phase model of asynchronous machines operating at medium or high frequencies is presented. It can be used to study the propagation of surge waves along the stator windings of induction form-wound machines. The model is derived from an analogy with a three-phase transmission line. The use of time-space Clarke vectors allows the introduction of mutual coupling between phases. The analytical expressions for voltage waves are derived and the distributed parameters of the model are calculated by means of finite-element method (FEM), considering a specific induction machine that was studied by other authors. Some examples are proposed in order to confirm the model validity and to underline certain fundamental aspects of the project of three-phase stator windings of induction machines. The applications considered leads to numerical results in qualitative agreement with those calculated and/or measured by other authors. In a forthcoming work on the subject, the authors propose to compare the theoretical results presented here with those resulting from an experimental campaign. |
| Autors: Clerici, D.;Della Torre, F.;Paolo Morando, A.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 199 - 206 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A General Framework to Detect Unsafe System States From Multisensor Data Stream |
Abstract:
This paper proposes a general framework for detecting unsafe states of a system whose basic real-time parameters are captured by multiple sensors. Our approach is to learn a danger-level function that can be used to alert the users of dangerous situations in advance so that certain measures can be taken to avoid the collapse. The main challenge to this learning problem is the labeling issue, i.e., it is difficult to assign an objective danger level at each time step to the training data, except at the collapse points, where a definitive penalty can be assigned, and at the successful ends, where a certain reward can be assigned. In this paper, we treat the danger level as an expected future reward (a penalty is regarded as a negative reward) and use temporal difference (TD) learning to learn a function for approximating the expected future reward, given the current and historical sensor readings. The TD learning obtains the approximation by propagating the penalties/rewards observable at collapse points or successful ends to the entire feature space following some constraints. This avoids the labeling issue and naturally allows a general framework to detect unsafe states. Our approach is applied to, but not limited to, the application of monitoring driving safety, and the experimental results demonstrate the effectiveness of the approach. |
| Autors: Ning, H.;Xu, W.;Zhou, Y.;Gong, Y.;Huang, T. S.; |
| Appeared in: IEEE Transactions on Intelligent Transportation Systems |
| Publication date: Mar 2010, volume: 11, issue:1, pages: 4 - 15 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Genetic Programming Approach for Software Reliability Modeling |
Abstract:
Genetic Programming (GP) models adapt better to the reliability curve when compared with other traditional, and non-parametric models. In a previous work, we conducted experiments with models based on time, and on coverage. We introduced an approach, named Genetic Programming and Boosting (GPB), that uses boosting techniques to improve the performance of GP. This approach presented better results than classical GP, but required ten times the number of executions. Therefore, we introduce in this paper a new GP based approach, named $(mu+lambda)$ GP. To evaluate this new approach, we repeated the same experiments conducted before. The results obtained show that the $(mu+lambda)$ GP approach presents the same cost of classical GP, and that there is no significant difference in the performance when compared with the GPB approach. Hence, it is an excellent, less expensive technique to model software reliability. |
| Autors: Costa, E. O.;Pozo, A. T. R.;Vergilio, S. R.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 222 - 230 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Geometrical Optics Model of Three Dimensional Scattering From a Rough Layer With Two Rough Surfaces |
Abstract:
An asymptotic method is described for predicting the bistatic normalized radar cross section of a rough homogeneous layer made up of two rough surfaces. The model is based on iteration of the Kirchhoff approximation to calculate the fields scattered by the rough layer, and is reduced to the high-frequency limit in order to obtain numerical results rapidly. Shadowing effects, significant for large incidence or scattering angles, are taken into account through the use of shadowing functions. The model is applicable for moderate to large surface roughnesses having small to moderate slopes, and for both lossless and lossy inner media. It was validated for a rough layer with a rough surface over a perfectly flat surface in a preceding contribution. Here, the extension of the model to a rough layer with two rough surfaces is developed, and results are presented to validate the asymptotic model by comparison with a numerical reference method. |
| Autors: Pinel, N.;Johnson, J. T.;Bourlier, C.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 809 - 816 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A gossiping protocol for detecting global threshold crossings |
Abstract:
We investigate the use of gossip protocols for the detection of network-wide threshold crossings. Our design goals are low protocol overhead, small detection delay, low probability of false positives and negatives, scalability, robustness to node failures and controllability of the trade-off between overhead and detection delay. Based on push-synopses, a gossip protocol introduced by Kempe et al., we present a protocol that indicates whether a global aggregate of static local values is above or below a given threshold. For this protocol, we prove correctness and show that it converges to a state with no overhead when the aggregate is sufficiently far from the threshold. Then, we introduce an extension we call TG-GAP, a protocol that (1) executes in a dynamic network environment where local values change and (2) implements hysteresis behavior with upper and lower thresholds. Key elements of its design are the construction of snapshots of the global aggregate for threshold detection and a mechanism for synchronizing local states, both of which are realized through the underlying gossip protocol. Simulation studies suggest that TG-GAP is efficient in that the protocol overhead is minimal when the aggregate is sufficiently far from the threshold, that its overhead and the detection delay are largely independent on the system size, and that the tradeoff between overhead and detection quality can be effectively controlled. Lastly, we perform a comparative evaluation of TG-GAP against a tree-based protocol. We conclude that, for detecting global threshold crossings in the type of scenarios investigated, the tree-based protocol incurs a significantly lower overhead and a smaller detection delay than a gossip protocol such as TG-GAP. |
| Autors: Wuhib, F.;Dam, M.;Stadler, R.; |
| Appeared in: IEEE Transactions on Network and Service Management |
| Publication date: Mar 2010, volume: 7, issue:1, pages: 42 - 57 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Holographic Antenna Approach for Surface Wave Control in Microstrip Antenna Applications |
Abstract:
A holographic antenna inspired structure is used to control the surface wave (SW) excited by a microstrip patch antenna. The hologram is designed to support a periodic leaky-wave which radiates at broadside and enhances the radiation of the patch while suppressing the horizontal lobe. In this design, the holographic approach is adapted for patch antenna applications where the SW wavelengths are comparable to the freespace wavelength. This is achieved by introducing dual phase-shifting metallic dipoles with periodic spacings. This paper discusses a simple and intuitive design method for the holographic surface, as well as its integration with the microstrip patch. The initial design concept was developed by assuming small perturbation to the SW, which was subsequently verified through full-wave simulations and prototype measurements. The results verified the improvements in the broadside gain and SW efficiency of the microstrip patch at the cost of increased area. |
| Autors: Sutinjo, A.;Okoniewski, M.;Johnston, R. H.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 675 - 682 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Hybrid Approach for Generating Secure and Discriminating Face Template |
Abstract:
Biometric template protection is one of the most important issues in deploying a practical biometric system. To tackle this problem, many algorithms, that do not store the template in its original form, have been reported in recent years. They can be categorized into two approaches, namely biometric cryptosystem and transform-based. However, most (if not all) algorithms in both approaches offer a trade-off between the template security and matching performance. Moreover, we believe that no single template protection method is capable of satisfying the security and performance simultaneously. In this paper, we propose a hybrid approach which takes advantage of both the biometric cryptosystem approach and the transform-based approach. A three-step hybrid algorithm is designed and developed based on random projection, discriminability-preserving (DP) transform, and fuzzy commitment scheme. The proposed algorithm not only provides good security, but also enhances the performance through the DP transform. Three publicly available face databases, namely FERET, CMU-PIE, and FRGC, are used for evaluation. The security strength of the binary templates generated from FERET, CMU-PIE, and FRGC databases are 206.3, 203.5, and 347.3 bits, respectively. Moreover, noninvertibility analysis and discussion on data leakage of the proposed hybrid algorithm are also reported. Experimental results show that, using Fisherface to construct the input facial feature vector (face template), the proposed hybrid method can improve the recognition accuracy by 4%, 11%, and 15% on the FERET, CMU-PIE, and FRGC databases, respectively. A comparison with the recently developed random multispace quantization biohashing algorithm is also reported. |
| Autors: Feng, Y. C.;Yuen, P. C.;Jain, A. K.; |
| Appeared in: IEEE Transactions on Information Forensics and Security |
| Publication date: Mar 2010, volume: 5, issue:1, pages: 103 - 117 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Hybrid Particle Approach for GNSS Applications With Partial GPS Outages |
Abstract:
To provide an accurate positioning, the land vehicle navigation applications are based on global positioning system (GPS). The addition of a digital road map allows locating the vehicle continuously and helps the driver to get the best path. These systems are usually enhanced with dead reckoning sensors due to GPS outages in urban areas in particular. For instance, the odometer sensors can be used to correct the vehicle location in this case. We present here a global estimation method of solving the fusion problem of the GPS, odometer, and digital road map measurements in the presence of GPS outages. It relies on a hybrid filter that takes advantage of the combination of a Kalman filter, which computes the linear part of the state equations and a particle filter to provide an optimal resolution scheme. When GPS fails, the filter fuses all available pseudorange measures to improve the vehicle positioning. In the case of an urban transport scenario, the results show that the number of particles is significantly reduced to achieve the same performance of a single particle filter in terms of accuracy. Moreover, software solutions can be developed for real-time applications. |
| Autors: Boucher, C.;Noyer, J.-C.; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 498 - 505 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Limited Feedback Joint Precoding for Amplify-and-Forward Relaying |
Abstract:
This paper deals with the practical precoding design for a dual hop downlink with multiple-input multiple-output (MIMO) amplify-and-forward relaying. First, assuming that full channel state information (CSI) of the two hop channels is available, a suboptimal dual hop joint precoding scheme, i.e., precoding at both the base station and relay station, is investigated. Based on its structure, a scheme of limited feedback joint precoding using joint codebooks is then proposed, which uses a distributed codeword selection to concurrently choose two joint precoders such that the feedback delay is considerably decreased. Finally, the joint codebook design for the limited feedback joint precoding system is analyzed, and results reveal that independent codebook designs at the base station and relay station using the conventional Grassmannian subspace packing method is able to guarantee that the overall performance of the dual hop joint precoding scheme improves with the size of each of the two codebooks. Simulation results show that the proposed dual hop joint precoding system using distributed codeword selection scheme exhibits a rate or BER performance close to the one using the optimal centralized codeword selection scheme, while having lower computational complexity and shorter feedback delay. |
| Autors: Yongming Huang;Luxi Yang;Bengtsson, M.;Ottersten, B.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 1347 - 1357 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Linear Rectangular Dielectric Resonator Antenna Array Fed by Dielectric Image Guide With Low Cross Polarization |
Abstract:
Design of a linear array of rectangular dielectric resonator antennas (DRAs) fed by dielectric image guide (DIG) is presented. Coupling between the DIG and the DRAs is predicted using the effective dielectric constant method. In order to achieve a specific power distribution, the power coupled to each DRA is controlled by changing the spacing between the DRAs and the DIG. Cross polarization reduction is achieved by wrapping a conducting strip around the middle of the DRA without affecting the co-polarized radiation pattern. The antenna is fabricated and tested. Good agreement between the measured and computed results is obtained. |
| Autors: Al-Zoubi, A. S.;Kishk, A. A.;Glisson, A. W.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 697 - 705 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Cost VLSI Implementation for Efficient Removal of Impulse Noise |
Abstract:
Image and video signals might be corrupted by impulse noise in the process of signal acquisition and transmission. In this paper, an efficient VLSI implementation for removing impulse noise is presented. Our extensive experimental results show that the proposed technique preserves the edge features and obtains excellent performances in terms of quantitative evaluation and visual quality. The design requires only low computational complexity and two line memory buffers. Its hardware cost is quite low. Compared with previous VLSI implementations, our design achieves better image quality with less hardware cost. Synthesis results show that the proposed design yields a processing rate of about 167 M samples/second by using TSMC 0.18 $muhbox{m}$ technology. |
| Autors: Chen, P.-Y.;Lien, C.-Y.;Chuang, H.-M.; |
| Appeared in: IEEE Transactions on Very Large Scale Integration Systems |
| Publication date: Mar 2010, volume: 18, issue:3, pages: 473 - 481 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Power Continuously-Calibrated Clock Recovery Circuit for UHF RFID EPC Class-1 Generation-2 Transponders |
Abstract:
A low-power, reliable and re-configurable clock recovery circuit for UHF RFID transponders for the EPC Class-1 Generation-2 standard is proposed. Based on a digital frequency-locked loop, the clock recovery circuit uses timing information available in the downlink data, namely, the pulse intervals of the PIE-coded data, to calibrate an oscillator's output frequency to meet the stringent frequency accuracy requirement of the standard. Fabricated in a 0.18-$mu{hbox {m}}$ standard CMOS technology, the clock recovery circuit provides a calibrated frequency of 2.56 MHz with a frequency deviation within the range from $-$3.2% to $+ $1.2% over process, supply voltage and temperature variations. The chip has an active area of 0.22$~mu{hbox {m}}^{2}$, operates from a supply voltage from 0.75 V to 1.3 V, and consumes less than 2$~mu{hbox {W}}$ for a 1-V supply. |
| Autors: Chan, C.-F.;Pun, K.-P.;Leung, K.-N.;Guo, J.;Leung, L.-K. L.;Choy, C.-S.; |
| Appeared in: IEEE Journal of Solid-State Circuits |
| Publication date: Mar 2010, volume: 45, issue:3, pages: 587 - 599 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Power Stand-Alone Adaptive Circuit for Harvesting Energy From a Piezoelectric Micropower Generator |
Abstract:
An adaptive energy-harvesting circuit with low power dissipation is presented and demonstrated, which is useful for efficient ac/dc voltage conversion of a piezoelectric micropower generator. The circuit operates stand-alone, and it extracts the piezoelectric strain energy independent of the load and piezoelectric parameters without using any external sensor. The circuit consists of a voltage-doubler rectifier, a step-down switching converter, and an analog controller operating with a single supply voltage in the range of 2.5–15 V. The controller uses the piezoelectric voltage as a feedback and regulates the rectified voltage to adaptively improve the extracted power. The nonscalable power dissipation of the controller unit is less than 0.05 mW, and the efficiency of the circuit is about 60% for output power levels above 0.5 mW. Experimental verifications of the circuit show the following: 1) the circuit notably increases the extracted power from a piezoelectric element compared to a simple full-bridge diode rectifier without control circuitry, and 2) the efficiency of the circuit is dominantly determined by its switching converter. The simplicity of the circuit facilitates the development of efficient piezoelectric energy harvesters for low-power applications such as wireless sensors and portable devices. |
| Autors: Tabesh, A.;Frechette, L. G.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 840 - 849 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Low-Power, Battery-Free Tag for Body Sensor Networks |
Abstract:
A new tag for pervasive sensing applications consists of a custom integrated circuit, an antenna for radio frequency energy harvesting, and sensors for monitoring physiological parameters. This paper presents a wearable tag design that can monitor multiple signals. The tag generates an alarm when it suspects a patient emergency. To quickly cover a large portion of the population at risk, we kept the tag affordable (less than US$2 each when manufactured in volume), disposable, small, and easy to use. Such tags would be useful for hospitals, facilities for infants and the elderly, and ordinary homes to detect and alert caregivers to possible problems including SCA and SIDS. |
| Autors: Mandal, S.;Turicchia, L.;Sarpeshkar, R.; |
| Appeared in: IEEE Pervasive Computing |
| Publication date: Mar 2010, volume: 9, issue:1, pages: 71 - 77 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Method for Delivering Spatio-Temporally Focused Energy to a Dynamically Adjustable Target Along a Waveguiding Structure |
Abstract:
It is possible to exploit the frequency-dependent velocity dispersion inherent to waveguiding structures to deliver spatio-temporally focused energy to a spatial target anywhere along the longitudinal extent of a waveguide. Such focusing of energy may have application to technologies as varied as nerve stimulation or chemical etching. A waveguide signal that effects this focused energy is conceptualized and derived. The spatial location of the target acted upon by the waveguide signal is demonstrated to be dynamically adjustable with a linear filtering step. Optimal parameters for waveguide signal generation are derived in the general case, allowing for application to a cross section of homogeneous waveguides. Performance is also considered in non-ideal, absorptive media. Numerical simulations are presented that indicate agreement with analytic results, and an evaluation of possible reduction to practice is presented. |
| Autors: Laflen, J.B.;Talavage, T.M.; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 1416 - 1426 |
| Publisher: IEEE |
| Full litterature document |
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|
» A Min–Max Optimization Framework for Designing  Learners: Theory and Hardware |
Abstract:
In this paper, we present a framework for constructing $SigmaDelta$ learning algorithms and hardware that can identify and track low-dimensional manifolds embedded in a high-dimensional analog signal space. At the core of the proposed approach is a min–max stochastic optimization of a regularized cost function that combines machine learning with $SigmaDelta$ modulation. As a result, the algorithm not only produces a quantized sequence of the transformed analog signals but also a quantized representation of the transform itself. The framework is generic and can be extended to higher order $SigmaDelta$ modulators and for different signal transformations. In this paper, the $SigmaDelta$ learning is demonstrated for identifying linear compression manifolds, which can eliminate redundant AD conversion (ADC) paths. This improves the energy efficiency of the proposed architecture compared to a conventional multichannel data acquisition system. Measured results from a four channel prototype fabricated in a 0.5 $mu$ m CMOS process has been used to verify the energy efficiency of the $SigmaDelta$ learner and to demonstrate its real-time adaptation capabilities that are consistent with the theoretical and simulated results. One of the salient features of $SigmaDelta$ learning is its self-calibration property, whereby the performance remains unchanged even in the presence of computational artifacts (mismatch and nonlinearities). This property makes the proposed architecture ideal for impleme-
nting practical high-dimensional AD converters. |
| Autors: Gore, A.;Chakrabartty, S.; |
| Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 604 - 617 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Model-Based Fault-Detection and Prediction Scheme for Nonlinear Multivariable Discrete-Time Systems With Asymptotic Stability Guarantees |
Abstract:
In this paper, a novel, unified model-based fault-detection and prediction (FDP) scheme is developed for nonlinear multiple-input–multiple-output (MIMO) discrete-time systems. The proposed scheme addresses both state and output faults by considering separate time profiles. The faults, which could be incipient or abrupt, are modeled using input and output signals of the system. The fault-detection (FD) scheme comprises online approximator in discrete time (OLAD) with a robust adaptive term. An output residual is generated by comparing the FD estimator output with that of the measured system output. A fault is detected when this output residual exceeds a predefined threshold. Upon detecting the fault, the robust adaptive terms and the OLADs are initiated wherein the OLAD approximates the unknown fault dynamics online while the robust adaptive terms help in ensuring asymptotic stability of the FD design. Using the OLAD outputs, a fault diagnosis scheme is introduced. A stable parameter update law is developed not only to tune the OLAD parameters but also to estimate the time to failure (TTF), which is considered as a first step for prognostics. The asymptotic stability of the FDP scheme enhances the detection and TTF accuracy. The effectiveness of the proposed approach is demonstrated using a fourth-order MIMO satellite system. |
| Autors: Thumati, B. T.;Jagannathan, S.; |
| Appeared in: IEEE Transactions on Neural Networks |
| Publication date: Mar 2010, volume: 21, issue:3, pages: 404 - 423 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Modeling of Singing Voice Robust to Accompaniment Sounds and Its Application to Singer Identification and Vocal-Timbre-Similarity-Based Music Information Retrieval |
Abstract:
This paper describes a method of modeling the characteristics of a singing voice from polyphonic musical audio signals including sounds of various musical instruments. Because singing voices play an important role in musical pieces with vocals, such representation is useful for music information retrieval systems. The main problem in modeling the characteristics of a singing voice is the negative influences caused by accompaniment sounds. To solve this problem, we developed two methods, accompaniment sound reduction and reliable frame selection . The former makes it possible to calculate feature vectors that represent a spectral envelope of a singing voice after reducing accompaniment sounds. It first extracts the harmonic components of the predominant melody from sound mixtures and then resynthesizes the melody by using a sinusoidal model driven by these components. The latter method then estimates the reliability of frame of the obtained melody (i.e., the influence of accompaniment sound) by using two Gaussian mixture models (GMMs) for vocal and nonvocal frames to select the reliable vocal portions of musical pieces. Finally, each song is represented by its GMM consisting of the reliable frames. This new representation of the singing voice is demonstrated to improve the performance of an automatic singer identification system and to achieve an MIR system based on vocal timbre similarity. |
| Autors: Fujihara, H.;Goto, M.;Kitahara, T.;Okuno, H.G.; |
| Appeared in: IEEE Transactions on Audio, Speech, and Language Processing |
| Publication date: Mar 2010, volume: 18, issue:3, pages: 638 - 648 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Multiobjective Parametric Optimization for Passenger-Car Steering Actuator |
Abstract:
A robust design for the size optimization of a motor-driven steer applied in a compact car, using the design of simulation trial, is described and illustrated in this paper. The objective of the optimal design using the combined design of simulation trial and finite-element analysis (FEA) approach is to ensure that the motor-driven steer's performance for compact cars is insensitive to noise, with moderate computational effort. The optimal design process takes into consideration noises that arise in the unexpected load condition, such as tolerances for parameter variation of the electric motor and reduction gear in the actuator. The optimization is realized by a simulation and analysis tool that integrates the Target-wise Parameter Optimization and the FEA. The proposed procedure can not only reduce the size of an actuator but also raise the system efficiency of the motor-driven steering (MDS). In this paper, we have used an orthogonal array ${rm L}18(2^{1} times 3^{7})$ to implement simulation trials and made a response table and graph of control factors. Eventually, the optimal values of the control factors, the diameter of the stator core, the width of the wire, the turn number of the wire, the gear ratio of the worm and worm-wheel gear, the surface flux density of the magnet, the armature core's stack factor, and the module ratio of the worm and worm-wheel gear were decided, and then, the signal-to-noise ratio (SNR) was increased to 20.58%. The simulation results demonstrated that the proposed method applied to the optimal design of the MDS' actuator was feasible and efficient. In this paper, the design optimization process is described, and the results are presented. |
| Autors: Choi, H.-R.;Choe, G.-H.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 900 - 908 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Multiple-Filter-Multiple-Wrapper Approach to Gene Selection and Microarray Data Classification |
Abstract:
Filters and wrappers are two prevailing approaches for gene selection in microarray data analysis. Filters make use of statistical properties of each gene to represent its discriminating power between different classes. The computation is fast but the predictions are inaccurate. Wrappers make use of a chosen classifier to select genes by maximizing classification accuracy, but the computation burden is formidable. Filters and wrappers have been combined in previous studies to maximize the classification accuracy for a chosen classifier with respect to a filtered set of genes. The drawback of this single-filter-single-wrapper (SFSW) approach is that the classification accuracy is dependent on the choice of specific filter and wrapper. In this paper, a multiple-filter-multiple-wrapper (MFMW) approach is proposed that makes use of multiple filters and multiple wrappers to improve the accuracy and robustness of the classification, and to identify potential biomarker genes. Experiments based on six benchmark data sets show that the MFMW approach outperforms SFSW models (generated by all combinations of filters and wrappers used in the corresponding MFMW model) in all cases and for all six data sets. Some of MFMW-selected genes have been confirmed to be biomarkers or contribute to the development of particular cancers by other studies. |
| Autors: Yukyee Leung;Yeungsam Hung; |
| Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics |
| Publication date: Mar 2010, volume: 7, issue:1, pages: 108 - 117 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Multirate Field Construction Technique for Efficient Modeling of the Fields and Forces Within Inverter-Fed Induction Machines |
Abstract:
In recent research, a field construction technique (FCT) was derived to enable more efficient evaluation of the magnetic fields and forces within induction machines. Using the FCT, the results of two finite-element (FE) solutions are used to establish basis functions for the flux densities in the airgap of the machine. The basis functions are then used to predict the magnetic fields and forces under arbitrary stator excitation. In this paper, a multirate FCT (MRFCT) is proposed to enable efficient FCT modeling of machines that are connected to power electronic converters. Within the MRFCT, the low- and high-frequency components of the stator current are partitioned. The partitioned currents are then used to calculate the flux density and forces at time steps commensurate with the respective low- and high-frequency dynamics. It is shown that applying the MRFCT, the forces and fields of a machine connected to a power electronic circuit can be obtained at a small fraction of the time required for a coupled FE/circuit model. |
| Autors: Wu, D.;Pekarek, S. D.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 217 - 227 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Narrow-Angle Directional Microphone With Suppressed Rear Sensitivity |
Abstract:
A novel microphone that enables rear sensitivity to be significantly suppressed has been developed to improve open-air recording quality. Its assembly comprises a line microphone capsule and a second-order pressure gradient directional microphone. In conventional line microphones, residual rear sensitivity causes an influx of unexpected noise, especially at lower frequencies. Our microphone successfully suppresses rear sensitivity by more than 10 dB compared to conventional line microphones in the frequency range below 1 kHz in which major outdoor noise often occurs. Furthermore, it needs no complicated signal processing circuit and can be driven by a normal 48 V phantom power supply. Finally, our microphone was tested in on-the-spot broadcasts. Its rear sensitivity suppression proved to be effective for practical use, and its sound quality was found to be sufficient for use in TV programs. This paper describes the fundamental principle of the microphone's rear sensitivity suppression, the measurement results of its acoustic characteristics and field-test results obtained with it in on-the-spot broadcasts. |
| Autors: Sugimoto, T.;Iwaki, M.;Ono, K.;Ando, A.;Ishii, T.;Imanaga, K.;Chiba, Y.; |
| Appeared in: IEEE Transactions on Broadcasting |
| Publication date: Mar 2010, volume: 56, issue:1, pages: 92 - 97 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Algorithm to Photovoltaic Power Point Tracking Problems With Quadratic Maximization |
Abstract:
One of critical concerns in the operation of the photovoltaic system is the maximum power point (MPP) tracking problem that increases the economical feasibility of the system. This letter presents a tracking method using the quadratic polynomial to perform a MPP tracker of a given photovoltaic array. With the method, the maximum power calculation is made from a quadratic manner that it convergences significantly accelerated. |
| Autors: Pai, F.;Chao, R.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 262 - 264 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Analytical Model of the Erasing Operation in Phase-Change Memories |
Abstract:
In this letter, we present a new analytical model of the erasing operation in phase-change memories (PCMs). The model successfully describes the dynamics of the erasing curves of PCM arrays in terms of a filamentation picture of the electronic switching process. We also suggest a physical link between the crystalline fraction concept and the filamentation properties, thus providing a deeper comprehension of the underlying physics. The model is able to take into account both technological and architectural parameters, and it is suitable for the statistical analysis of PCM arrays. |
| Autors: Chimenton, A.;Zambelli, C.;Olivo, P.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Mar 2010, volume: 31, issue:3, pages: 198 - 200 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A new attack on art fraud |
Abstract:
Every few years, we're wowed by news of some jaw-dropping sum paid for a previously unknown painting or drawing by a famous artist. But how can a buyer truly be sure that a piece is a legitimate creation of, say, Leonardo or Gauguin? Mathematicians at Dartmouth College, in Hanover, N.H., may have the answer. They recently presented a computer-based statistical analysis technique which they say will help art historians and conservators discover even the most skilled forgery. |
| Autors: Jones, W.D.; |
| Appeared in: IEEE Spectrum |
| Publication date: Mar 2010, volume: 47, issue:3, pages: 18 - 18 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Criterion for the Quantification of Broken Rotor Bars in Induction Motors |
Abstract:
This paper addresses itself to evaluate quantitatively the severity of broken rotor bar (BRB) fault, i.e., the number of BRBs in induction motors. Sideband components are induced in stator current if BRB fault is present and commonly used for diagnosis purposes. Filippetti criterion has been proposed and developed in the literature to quantify the severity of BRB fault by using sideband components, however, with unsatisfactory universality/accuracy. This paper briefly analyzes Filippetti criterion, and mathematically derives a new criterion for the quantification of BRBs, based on the electromagnetic mechanism of sideband components. Comparing to Filippetti criterion, the universality and accuracy of the new criterion are both improved. Moreover, the new criterion includes the influence from the interbar currents associated with BRB fault. The related experiment on a 3-kW, 380-V, 50-Hz induction motor has been conducted, and results show the superiority of the new criterion over Filippetti criterion. |
| Autors: Xu, B.;Sun , L.;Ren, H.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 100 - 106 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Efficient Algorithm for Generating All Minimal Tie-Sets Connecting Selected Nodes in a Mesh-Structured Network |
Abstract:
This paper presents a new, efficient method of enumerating all minimal tie-sets connecting selected nodes in a mesh-structured network. More precisely, it gives a solution of the following problem: given a network modeled by an undirected graph ${rm G}=({rm V},{rm E})$, V, and E being the sets of G's vertices, and edges, find each minimal tie-set connecting all nodes of ${rm W}={{rm v}_{1},ldots,{rm v}_{rm k}}$ , a subset of V. (Note that for ${rm W}={rm V}$ the sought tie-sets are the spanning trees of G.) This task is fulfilled in two steps. In the first step, the sets ${rm P}_{2},ldots,{rm P}_{rm k}$ are found, where ${rm P}_{rm i}$ is the set of all loop-free paths connecting ${rm v}_{1}$ to ${rm v}_{rm i}$. This can be done by performing a breadth-first search on G. In the second step, a recursive procedure gradually merges the paths belonging to different sets ${rm P}_{rm i}$, and accomplishes the main task in ${rm k}-2$ iterations. Thus, the new method can be named Acyclic Paths Mergence (APM). This method is compared to the well known Backtracking algorithm; all spanning trees of a small graph are found using both approaches, and the APM method proves more efficient. This difference in efficiency is likely to grow with the size of G. Moreover, the similar complexity of the Backtracking, and the Edge Replacement (another “classic&#x-
201D; algorithm finding all spanning trees in a graph) methods, and wider applicability of the APM method, are additional arguments in favor of the latter. |
| Autors: Malinowski, J.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 203 - 211 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Fast Physical Optics for Smooth Surfaces by Means of a Numerical Theory of Diffraction |
Abstract:
A new technique to compute the physical optics (PO) integral is presented. The technique consists of a blind code that computes the different contributions (stationary phase points, end points, etc.) numerically. This technique is based on a decomposition of the surface into small triangles and a fast evaluation of each triangle by means of a deformation of the integration path in the complex plane. This algorithm permits a fast and accurate evaluation of the PO integral for smooth large surfaces. The CPU time is almost independent of frequency. |
| Autors: Vico-Bondia, F.;Ferrando-Bataller, M.;Valero-Nogueira, A.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 773 - 789 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Framework for Adaptive Multimodal Biometrics Management |
Abstract:
This paper presents a new evolutionary approach for adaptive combination of multiple biometrics to ensure the optimal performance for the desired level of security. The adaptive combination of multiple biometrics is employed to determine the optimal fusion strategy and the corresponding fusion parameters. The score-level fusion rules are adapted to ensure the desired system performance using a hybrid particle swarm optimization model. The rigorous experimental results presented in this paper illustrate that the proposed score-level approach can achieve significantly better and stable performance over the decision-level approach. There has been very little effort in the literature to investigate the performance of an adaptive multimodal fusion algorithm on real biometric data. This paper also presents the performance of the proposed approach from the real biometric samples which further validate the contributions from this paper. |
| Autors: Kumar, A.;Kanhangad, V.;Zhang, D.; |
| Appeared in: IEEE Transactions on Information Forensics and Security |
| Publication date: Mar 2010, volume: 5, issue:1, pages: 92 - 102 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A new method to reduce frequency-temperature coefficient of sapphire-loaded cavities for compact hydrogen masers |
Abstract:
To reduce the size and weight of the hydrogen maser atomic clocks, some useful attempts and related research results about sapphire-loaded cylindrical cavities for hydrogen masers were reported by the Beijing Institute of Radio Metrology and Measurement. The fractional frequency stability of the order of 10¿15 over 10 000 seconds can be realized. However, because of a large frequency-temperature coefficient in a single sapphire bulb in the cavity, further improvement of the stability in the compact hydrogen clock was restricted. In this work, we chose several small single-crystal chips of SrTiO3 with a large negative frequency-temperature coefficient to compensate the sapphire microwave cavity. Based on the theoretical calculation, the frequency-temperature coefficient in the TE011 mode of a sapphire cavity associated with several small chips of SrTiO3 can be greatly reduced. A sapphire-loaded cavity and 8 compensated chips of SrTiO3 were prepared, and a combined cavity was simulated by finite element method and measured by experiments. When quality factor was kept above 40 000, the frequency-temperature coefficient can be reduced to about 1/5 of its starting value. The experimental results agree very well with the calculation and simulation. Furthermore, this new method was applied in the compact hydrogen maser. Because of the decrease of temperature frequency shift, the hydrogen maser stability at medium- and long- term averaging time from 1 s to 105 s has an obvious improvement compared with the our previous results. |
| Autors: Ren-fu Yang;Tie-zhong Zhou;Hai-bo Chen;Nuan-rang Wang;Lian-shan Gao; |
| Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 583 - 586 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Neural-Network-Based Fault Diagnosis Approach for Analog Circuits by Using Kurtosis and Entropy as a Preprocessor |
Abstract:
This paper presents a new fault diagnosis method for analog circuits. The proposed method extracts the original signals from the output terminals of the circuits under test (CUTs) by a data acquisition board and finds the kurtoses and entropies of the signals, which are used to measure the high-order statistics of the signals. The entropies and kurtoses are then fed to a neural network as inputs for further fault classification. The proposed method can detect and identify faulty components in an analog circuit by analyzing its output signal with high accuracy and is suitable for nonlinear circuits. Preprocessing based on the kurtosis and entropy of signals for the neural network classifier simplifies the network architecture, reduces the training time, and improves the performance of the network. The results from our examples showed that the trochoid of the entropies and kurtoses is unique when the faulty component's value varies from zero to infinity; thus, we can correctly identify the faulty components when the responses do not overlap. Applying this method for three linear and nonlinear circuits, the average accuracy of the achieved fault recognition is more than 99%, although there are some overlapping data when tolerance is considered. Moreover, all the trochoids converge to one point when the faulty component is open-circuited, and thus, the method can classify not only soft faults but also hard faults. |
| Autors: Lifen Yuan;Yigang He;Jiaoying Huang;Yichuang Sun; |
| Appeared in: IEEE Transactions on Instrumentation and Measurement |
| Publication date: Mar 2010, volume: 59, issue:3, pages: 586 - 595 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Procedure for Assessing the Sensitivity of Antennas Using the Unscented Transform |
Abstract:
In this communication, we introduce a new procedure to analyze the sensitivity of antennas. The procedure is based on the method of unscented transform (UT) developed by Julier and Uhlman in 1997. Although the UT is used in control engineering, the method has only recently been applied to electromagnetic (EM) problems. This work describes the application of the UT both for single and multiple random variables cases. The UT method is applied to problems using examples involving different types of antennas. In each example, the UT method is combined with different numerical methods to perform the sensitivity analysis of wire or reflector antennas. In the first example, the results were validated with results from the Monte Carlo technique. The second example investigated the convergence of the UT procedure, and the final example compared UT results with measured data. The main conclusion is that UT is a feasible alternative to the popular Monte Carlo technique, with the advantage of being far less computationally expensive. |
| Autors: deMenezes, L. R. A. X.;Soares, A. J. M.;Silva, F. C.;Terada, M. A. B.;Correia, D.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 988 - 993 |
| Publisher: IEEE |
| Full litterature document |
| |
|
| » A New Reliability Prediction Model in Manufacturing Systems |
Abstract:
Reliability prediction has been widely studied in many research fields to improve product and system reliability in manufacturing systems. Traditionally, to establish the prediction model, modelers would use all training data without preference. However, the prediction model based only on the most recent data may have better performance. In this paper, to realize an accurate prediction with the most recent data sets, we use the grey model to establish the reliability model. Then, the cubic spline function is integrated into the grey model to enhance the prediction capability of GM(1, 1), a single variable first order grey model. The newly generated model is defined as 3spGM(1, 1). To further improve the prediction accuracy, the particle swarm optimization (PSO) algorithm is applied to 3spGM(1, 1). We call the improved version P-3spGM(1, 1). Finally, we validated the effectiveness of the proposed model using failure data sets of electric product manufacturing systems. |
| Autors: Li, G.-D.;Masuda, S.;Yamaguchi, D.;Nagai, M.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 170 - 177 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Shorted Microstrip Method to Determine the Complex Permeability of Thin Films |
Abstract:
A new method is proposed to determine the complex permeability of ferromagnetic thin films from 100 MHz to 15 GHz. In this method, shorted microstrip transmission-line perturbation combined with the conformal mapping method is used. In contrast with previous methods to measure the thin films deposited on rigid substrates, this method neither requires any reference sample for calibration, nor requires the additional measurement to determine saturation magnetization. To assess the validity of this new method, three samples with different thicknesses are measured; comparisons are performed between the theoretical and experimental results, and the repeatability of this method is studied by measuring the samples five times. The results show that the complex permeability of ferromagnetic thin films can be measured within 10% errors. |
| Autors: Wu, Y.;Tang, Z.;Xu, Y.;Zhang, B.;He, X.; |
| Appeared in: IEEE Transactions on Magnetics |
| Publication date: Mar 2010, volume: 46, issue:3, pages: 886 - 888 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A New Start-Up Demonstration Test |
Abstract:
The commonly known consecutive successes total failures (CSTF) start-up demonstration test procedure is improved to a total successes consecutive successes total failures (TSCSTF) procedure. Accordingly, a unit under test is accepted when either a total number of successful tests, or a specified number of consecutive successes of tests are observed before a total number of failures; otherwise the unit is rejected. The waiting time until termination (the length of the set of tests) of the new procedure is evaluated. A correct choice of parameters (e.g. the number of successes required for acceptance, the total number of failures causing rejection) using the new procedure may yield a shorter waiting time than that of the relevant CSTF procedure. |
| Autors: Gera, A. E.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 128 - 131 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A new trapped ion atomic clock based on 201Hg+ |
Abstract:
High-resolution spectroscopy has been performed on the ground-state hyperfine transitions in trapped 201Hg+ ions as part of a program to investigate the viability of 201Hg+ for clock applications. Part of the spectroscopy work was directed at magnetic-field-sensitive hyperfine lines with δmF =0, which allow accurate Doppler-free measurement of the magnetic field experienced by the trapped ions. Although it is possible to measure Doppler-free magnetic-field-sensitive transitions in the commonly used clock isotope, 199Hg+, it is more difficult. In this paper, we discuss how this 199Hg+ feature may be exploited to produce a more stable clock or one requiring less magnetic shielding in environments with magnetic field fluctuations far in excess of what is normally found in the laboratory. We have also determined that in dischargelamp- based trapped mercury ion clocks, the optical pumping time for 201Hg+ is about 3 times shorter than that of 199Hg+ This can be used to reduce dead time in the interrogation cycle for these types of clocks, thereby reducing the impact of local oscillator noise aliasing effects. |
| Autors: Burt, E.A.;Taghavi-Larigani, S.;Tjoelker, R.L.; |
| Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 629 - 635 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Newly Developed Formulation Suitable for Matrix Manipulation of Layered Medium Green's Functions |
Abstract:
Based on a recently developed formulation of the dyadic Green's function for layered media (DGLM), this work gives the matrix element representation of the DGLM for general RWG basis functions, including basis functions straddling across different layers and half-RWG basis function attached to an infinite ground plane. It has been rigorously proved that this representation is absent of any undesired line integrals, the same as the popular Michalski-Zheng's formulation of type C. This work also gives the analytical solution for some typical cylindrically symmetric problems, which can be used to validate any formulation for layered medium problems. |
| Autors: Xiong, J. L.;Chew, W. C.; |
| Appeared in: IEEE Transactions on Antennas and Propagation |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 868 - 875 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Nonlinear Phenomenon on Self-Oscillating Current Controllers: The Indirect Synchronization |
Abstract:
In this paper, a particular phenomenon called indirect synchronization is investigated on self-oscillating current controllers. This phenomenon appears in medium frequencies, when the reference signal frequency tends to the switching frequency. In a previous work, it has been shown that the indirect synchronization causes discontinuities on the frequential response of the system, making the various linear or continuous models inefficient. For high-accuracy applications, such as active filtering or high-precision power supply, these discontinuities are a real problem. Thus, it seems important to offer an analytical description of this phenomenon. In this paper, an analytical model of the indirect synchronization phenomenon is proposed and checked by simulation and experimental results. |
| Autors: Olivier, J.-C.;Le Claire, J.-C.;Loron, L.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 1106 - 1111 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Nonparametric Feature Extraction and Its Application to Nearest Neighbor Classification for Hyperspectral Image Data |
Abstract:
Feature extraction plays an essential role in hyperspectral image classification. Nonparametric feature extraction algorithms have more advantages than parametric ones and are well suited for nonnormally distributed data along with being able to extract more features than the classic linear discriminant analysis. In this paper, a novel nonparametric feature extraction method, namely, cosine-based nonparametric feature extraction (CNFE), is proposed, in which the weight function embedded in the within-class and between-class scatter matrices is developed based on cosine distance. Moreover, a powerful $K$-nearest neighbor $(Khbox{NN})$ classification algorithm based on the distance metric formed by CNFE features is also developed, which is called the CNFE-based $Khbox{NN} (hbox{C}Khbox{NN})$ classifier. The effectiveness of the proposed CNFE and $hbox{C}Khbox{NN}$ is evaluated by two hyperspectral real data sets. The experimental results demonstrate that both the proposed CNFE and $ hbox{C}Khbox{NN}$ achieve remarkable performances on various types of training sample sizes, including the small-sample-size cases. |
| Autors: Yang, J.-M.;Yu, P.-T.;Kuo, B.-C.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Mar 2010, volume: 48, issue:3, pages: 1279 - 1293 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Nonvolatile InGaZnO Charge-Trapping-Engineered Flash Memory With Good Retention Characteristics |
Abstract:
We report an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor nonvolatile memory (NVM). This NVM shows a large 1.2-V extrapolated ten-year memory window, along with low 10-V/ $-$12-V program/erase voltage, fast 1-ms/100-$muhbox{s}$ speed, and good endurance. This was achieved using a charge-trap-engineered structure and high- $kappa$ layers. |
| Autors: Su, N. C.;Wang, S. J.;Chin, A.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Mar 2010, volume: 31, issue:3, pages: 201 - 203 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Normalized Framework for the Design of Feature Spaces Assessing the Left Ventricular Function |
Abstract:
A through description of the left ventricle functionality requires combining complementary regional scores. A main limitation is the lack of multiparametric normality models oriented to the assessment of regional wall motion abnormalities (RWMA). This paper covers two main topics involved in RWMA assessment. We propose a general framework allowing the fusion and comparison across subjects of different regional scores. Our framework is used to explore which combination of regional scores (including 2-D motion and strains) is better suited for RWMA detection. Our statistical analysis indicates that for a proper (within interobserver variability) identification of RWMA, models should consider motion and extreme strains. |
| Autors: Garcia-Barnes, J.;Gil, D.;Badiella, L.;Hernandez-Sabate, A.;Carreras, F.;Pujades, S.;Marti, E.; |
| Appeared in: IEEE Transactions on Medical Imaging |
| Publication date: Mar 2010, volume: 29, issue:3, pages: 733 - 745 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Approach to Monitor Rehabilitation Outcomes in Stroke Survivors Using Wearable Technology |
Abstract:
Quantitative assessment of motor abilities in stroke survivors can provide valuable feedback to guide clinical interventions. Numerous clinical scales were developed in the past to assess levels of impairment and functional limitation in individuals after stroke. The Functional Ability Scale is one of these clinical scales. It is a 75-point scale used to evaluate the functional ability of subjects by grading movement quality during performance of 15 motor tasks. Performance of these motor tasks requires subjects to reach for objects (e.g., a pencil on a table) and manipulate them (e.g., lift the pencil). In this paper, we show that accelerometer data recorded during performance of a subset of the motor tasks pertaining to the Functional Ability Scale can be relied upon to derive accurate estimates of the scores provided by a clinician using this scale. Accelerometer-based estimates of clinical scores were obtained by segmenting the recordings into movement components (reaching, manipulation, release/return), extracting data features, selecting features that maximized the separation among classes associated with different clinical scores, feeding these features to Random Forests to estimate scores for individual motor tasks, and using a linear equation to estimate the total Functional Ability Scale score based on the sum of the clinical scores for individual motor tasks derived from the accelerometer data. Results showed that it is possible to achieve estimates of the total Functional Ability Scale score marked by a bias of only 0.04 points of the scale and a standard deviation of only 2.43 points when using as few as three sensors to collect data during performance of only six motor tasks. |
| Autors: Patel, S.;Hughes, R.;Hester, T.;Stein, J.;Akay, M.;Dy, J. G.;Bonato, P.; |
| Appeared in: Proceedings of the IEEE |
| Publication date: Mar 2010, volume: 98, issue:3, pages: 450 - 461 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Control Technique for a Switched-Capacitor-Converter-Based Hybrid Electric Vehicle Energy Storage System |
Abstract:
This paper presents the analysis and novel controller design for a hybrid switched-capacitor bidirectional dc/dc converter. Features of voltage step-down, step-up, and bidirectional power flow are integrated into a single circuit. The novel control strategy enables simpler dynamics compared to a standard buck converter with an input filter, good regulation capability, low electromagnetic interference, lower source current ripple, ease of control, and continuous input current waveform in both modes of operation (buck and boost modes). |
| Autors: Amjadi, Z.;Williamson, S. S.; |
| Appeared in: IEEE Transactions on Industrial Electronics |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 926 - 934 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Highly Integrated SPM System for Single Molecule Studies |
Abstract:
The design and performance of a highly integrated scanning probe microscopy for single molecule studies is presented. The new approach realized tunable contact strength, stretching dynamics as well as electric potentials, which make it possible to tune and measure the single molecule electromechanic properties. The tunable contact strength is realized by a dual-feedback loop-controlled tip engagement with automatic mode switching. Electric current and stretching force of the molecular junctions are monitored simultaneously. In case of no current during the engage process, the system will automatically switch to traditional atomic force microscope force-feedback to protect the tip from crashing. The stretching dynamics is tuned by adapting programmable stretching behaviors. Tip-sample bias can also be swept when molecules are bridged in the break junctions. Applications of this system to octanedithiol (C8) molecules are also demonstrated. |
| Autors: Chen, F.;Zhou, J.;Chen, G.;Xu, B.; |
| Appeared in: IEEE Sensors Journal |
| Publication date: Mar 2010, volume: 10, issue:3, pages: 485 - 491 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Method to Estimate the O&M Costs for the Financial Planning of the Wind Power Projects Based on Wind Speed—A Case Study |
Abstract:
A novel analytical method is proposed to find the reliability, the average failure rate, and the operation and maintenance costs (OMCs) of wind turbine generator based on the site wind data. The failure rate function is developed using wind turbine failure frequency distribution, published by Renewable Energy Information System on Internet, Germany. The presented method works computationally fast and does not require large wind data input, which is a requirement of many existing, commercially available simulation methods. The annually increasing OMCs, computed by this method, give better financial assessment of the wind power projects. The method presented is implemented on an Indian wind site. OMCs are obtained for 20 years. Results match the actual field data, for the survey period, barring their warranty period. It is hoped that the proposed method helps financial investors and equity holders for a better financial assessment of the wind power projects at planning stage. |
| Autors: Joshi, D. R.;Jangamshetti, S. H.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 161 - 167 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Nanoscale 4H-SiC-on-Insulator MOSFET Using Step Doping Channel |
Abstract:
In this paper, we present the unique features exhibited by a novel step doping channel technique in nanoscale silicon carbide metal–oxide–semiconductor field-effect transistors (SDC-MOSFETs) for reaching a suitable threshold voltage upon device scaling and reliability improvement. The device demonstrates large enhancements in performance areas such as output resistance, hot-electron reliability, and threshold voltage upon channel-length or drain-voltage variation. Also, we describe an optimization technique in SDC-MOSFET for improving the threshold-voltage characterization. It was also found that the device performance is very much dependent upon the SDC region parameters. Results show that the most difficult problem of using silicon carbide in VLSI circuits could be solved and that the proposed silicon carbide MOSFETs can work very well in the nanoscale regime. |
| Autors: Orouji, A. A.;Elahipanah, H.; |
| Appeared in: IEEE Transactions on Device and Materials Reliability |
| Publication date: Mar 2010, volume: 10, issue:1, pages: 92 - 95 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Partial-Ground-Plane-Based MOSFET on Selective Buried Oxide: 2-D Simulation Study |
Abstract:
A novel partial-ground-plane (PGP)-based MOSFET on a selective buried oxide (SELBOX), named PGP-SELBOX, is proposed. An extensive simulation study and the comparative analysis of the key characteristics of the PGP-SELBOX, the SELBOX, and the conventional silicon-on-insulator (SOI) devices has been performed using the 2-D device simulator Medici. The simulations have revealed that the PGP-SELBOX and the SELBOX structures are more thermally efficient than the conventional SOI device. Further, the magnitude of the short-channel effects (SCEs) is lower in the PGP-SELBOX in comparison to the SELBOX device. Though the SCE suppression is best in the thin-film SOI device, the PGP-SELBOX shows better improvement in SCE suppression in comparison to the SELBOX device. The suppression of self-heating effects and SCEs in the PGP-SELBOX results in a significant reduction in leakage current. An improved performance in terms of $I_{rm ON}/I_{rm OFF}$ ratio is obtained in the PGP-SELBOX device. Further, the $f_{T}$ values of the PGP-SELBOX are comparable to those of the SELBOX and the SOI devices. A process flow in which a low-dose separation by implantation of oxygen technique can be employed for the fabrication of the PGP-SELBOX is also proposed. |
| Autors: Loan, S. A.;Qureshi, S.;Iyer, S. S. K.; |
| Appeared in: IEEE Transactions on Electron Devices |
| Publication date: Mar 2010, volume: 57, issue:3, pages: 671 - 680 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Protocol for Accuracy Assessment in Classification of Very High Resolution Images |
Abstract:
This paper presents a novel protocol for the accuracy assessment of the thematic maps obtained by the classification of very high resolution images. As the thematic accuracy alone is not sufficient to adequately characterize the geometrical properties of high-resolution classification maps, we propose a protocol that is based on the analysis of two families of indices: 1) the traditional thematic accuracy indices and 2) a set of novel geometric indices that model different geometric properties of the objects recognized in the map. In this context, we present a set of indices that characterize five different types of geometric errors in the classification map: 1) oversegmentation; 2) undersegmentation; 3) edge location; 4) shape distortion; and 5) fragmentation. Moreover, we propose a new approach for tuning the free parameters of supervised classifiers on the basis of a multiobjective criterion function that aims at selecting the parameter values that result in the classification map that jointly optimize thematic and geometric error indices. Experimental results obtained on QuickBird images show the effectiveness of the proposed protocol in selecting classification maps characterized by a better tradeoff between thematic and geometric accuracies than standard procedures based only on thematic accuracy measures. In addition, results obtained with support vector machine classifiers confirm the effectiveness of the proposed multiobjective technique for the selection of free-parameter values for the classification algorithm. |
| Autors: Persello, C.;Bruzzone, L.; |
| Appeared in: IEEE Transactions on Geoscience and Remote Sensing |
| Publication date: Mar 2010, volume: 48, issue:3, pages: 1232 - 1244 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Scheme for Rapid Tracking of Maximum Power Point in Wind Energy Generation Systems |
Abstract:
This paper presents a novel maximum power point (MPP) tracking (MPPT) algorithm for grid-connected wind energy generation systems (WEGS). This is a rapid tracking algorithm that uses the fact that the value of “β,” an intermediate variable, especially defined for the purpose, remains constant ( ${=}beta _{rm MPP}$ ) for a given WEGS at the MPP irrespective of the wind velocity. The value of $beta _{rm MPP}$ is known in advance. The algorithm works in two stages. In the first stage, it uses large steps to quickly drive the operating point to lie within a narrow band with limits $beta _{rm max}$ and $beta _{rm min}$. In the second stage, exact MPP is tracked using the “perturb and observe” method. No extra hardware or measurements (sensors) are required compared to the existing algorithms. Hence, the cost is not increased. Application of the proposed algorithm to an example WEGS shows that the time taken by the system to reach MPP is much smaller compared to most of the existing algorithms. A prototype matrix converter has been developed for grid interfacing and the proposed MPPT scheme has been implemented in conjunction with Venturini and space-vector-modulation-based switching schemes. All the results of this study are presented. |
| Autors: Agarwal , V.;Aggarwal, R. K.;Patidar, P. K.;Patki, C. K.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 228 - 236 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Sensorless MPPT Controller for a High-Efficiency Microscale Wind Power Generation System |
Abstract:
In this paper, a novel maximum power point tracking (MPPT) controller with an adaptive compensation control is first proposed for a microscale wind power generation system (WPGS). Based on the adaptive control, the dynamic response is improved and more wind energy can be captured during wind velocity variations. For cost and reliability consideration, no mechanical sensors are used in this proposed WPGS. A single-stage ac-to-dc converter is then proposed to replace the traditional two-stage converter and incorporate the MPPT control for achieving higher efficiency and lower total harmonic distortion (THD). To further improve the efficiency of the converter, a quasi-synchronous rectification (QSR) algorithm is proposed to control the active switches for reducing the conduction loss of the body diodes. The analytic closed form duty ratios of the corresponding active switches are also derived for easy implementation. Furthermore, a prototype system is constructed and the proposed MPPT controller and QSR algorithm are both implemented using a DSP, namely, TMS320F2812. Some experimental results are given to verify the validity of the proposed microscale WPGS. It is found that the total output energy can be increased by 13% for the microscale WPGS. |
| Autors: Pan, C.;Juan, Y.; |
| Appeared in: IEEE Transactions on Energy Conversion |
| Publication date: Mar 2010, volume: 25, issue:1, pages: 207 - 216 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Novel Thermo-pneumatic Peristaltic Micropump with Low Temperature Elevation on Working Fluid |
Abstract:
This work presents a novel thermo-pneumatic peristaltic micropump with low temperature elevation on working fluid. The proposed device, which consists of two separate zones for air-heating and fluid-squeezing, is realized by using micromachining techniques. Also, the device can be operated by using a small and simple actuation circuitry with low applied voltages. Under similar operational conditions, the proposed micropump shows similar fluid-pumping performance when compared with the conventional design of thermo-pneumatic micropumps. However, for the proposed design, the temperature elevation on the fluid-pumping area is as small as about 2.0K, which is less than 8% of that generated by the... |
| Autors: Bonnie Tingting, Chia , Hsin-Hung, Liao , Yao-Joe, Yang |
| Appeared in: Sensors and Actuators A: Physical |
| Publication date: Mar 2010 |
| Publisher: Elsevier B.V. |
| Full litterature document |
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|
| » A Particle Swarm Optimization Approach Based on Monte Carlo Simulation for Solving the Complex Network Reliability Problem |
Abstract:
Reliability optimization has been a popular area of research, and received significant attention due to the critical importance of reliability in various kinds of systems. Most network reliability optimization problems are only focused on solving simple structured networks (e.g., series-parallel networks) of which the reliability function can be easily obtained in advance. However, modern networks are usually very complex, and it is impossible to calculate the exact network reliability function by using traditional analytical methods in limited time. Hence, a new Particle Swarm Optimization (PSO) based on Monte Carlo Simulation (MCS), named MCS-PSO, has been proposed to solve complex network reliability optimization problems. The proposed MCS-PSO can minimize cost under reliability constraints. To the best of our knowledge, this is the first attempt to use PSO combined with MCS to solve complex network reliability problems without requiring knowledge of the reliability function in advance. Compared with previous works to solve this problem, the proposed MCS-PSO can have better efficiency by providing a better solution to the complex network reliability optimization problem. |
| Autors: Yeh, W.-C.;Lin, Y.-C.;Chung, Y. Y.;Chih, M.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 212 - 221 |
| Publisher: IEEE |
| Full litterature document |
| |
|
| » A petri nets-based process planning system for wastewater treatment |
Abstract:
It is always challenging to simulate, debug or diagnose automated systems. The aim of this paper is to present the development of a convenient tool for reengineering the control system in a complicated industrial wastewater treatment plant. In this project, a PC-based Human-Machine Interface (HMI) in conjunction with Petri nets (PN) theory is adopted to develop and simulate the operational process for wastewater treatment. The resultant tool offers many advantages to the reality of the automated control world. It not only reduces the process reengineering time and the cost of error recovery, but also builds a panel of human interface for the process. The discrete event control sequence of wastewater treatment can be easily modeled and evaluated before its build-up. Furthermore, this PN-based system can be used as an online diagnostic tool when the wastewater treatment process is malfunctioning. That is, the presented PN tool provides an adequate means for offline process development, simulation, performance evaluation, and quick online process diagnosis. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society |
| Autors: Albert W. L. Yao, Zhiming Ji, H. T. Liao |
| Appeared in: Asian Journal of Control |
| Publication date: Mar 2010 |
| Publisher: Wiley InterScience |
| Full litterature document |
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|
| » A Physical Model for GPS Multipath Caused by Land Reflections: Toward Bare Soil Moisture Retrievals |
Abstract:
Reflected Global Positioning System (GPS) signals can be used to infer information about soil moisture in the vicinity of the GPS antenna. Interference of direct and reflected signals causes the composite signal, observed using signal-to-noise ratio (SNR) data, to undulate with time while the GPS satellite ascends or descends at relatively low elevation angles. The soil moisture change affects both the phase of the SNR modulation pattern and its magnitude. In order to more thoroughly understand the mechanism of how the soil moisture change leads to a change in the SNR modulation, we built an electrodynamic model of GPS direct and reflected signal interference, i.e., multipath, that has a bare-soil model as the input and the total GPS received power as the output. This model treats soil as a continuously stratified medium with a specific composition of material ingredients having complex dielectric permittivity according to well-known mixing models. The critical part of this electrodynamic model is a numerical algorithm that allows us to calculate polarization-dependent reflection coefficients of such media with various profiles of dielectric permittivity dictated by the soil type and moisture. In this paper, we demonstrate how this model can reproduce and explain the main features of experimental multipath modulation patterns such as changes in phase and amplitude. We also discuss the interplay between true penetration depth and effective reflector depth. Based on these modeling comparisions, we formulate recommendations to improve the performance of bare soil moisture retrievals from the data obtained using GPS multipath modulation. |
| Autors: Zavorotny, V. U.;Larson, K. M.;Braun, J. J.;Small, E. E.;Gutmann, E. D.;Bilich, A. L.; |
| Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Publication date: Mar 2010, volume: 3, issue:1, pages: 100 - 110 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Practical Application of Quantitative Accelerated Life Testing in Power Systems Engineering |
Abstract:
Demonstrating product reliability is a common challenge within industry, and one that has become continuously more difficult to address due to the marketplace demands for decreased development time and cost. This challenge presents industry with new constraints as proven reliability assessment techniques are becoming increasingly difficult to apply due to the test duration standing in conflict with resource demands placed on engineering organizations. These limitations represent the main influence behind this paper, which explores an alternative reliability demonstration approach using quantitative accelerated life testing (QALT). Accelerated life testing is a reliability discipline that has been the focus of much research, and from which a great many publications have been derived. Yet many proposed approaches can be difficult to apply within industry due to the aforementioned resource constraints, and therefore an alternative methodology will be proposed that delivers accurate reliability data within the aforementioned constraints, thus addressing the limitations imposed by conventional reliability demonstration tests. |
| Autors: Turner, M. D.; |
| Appeared in: IEEE Transactions on Reliability |
| Publication date: Mar 2010, volume: 59, issue:1, pages: 91 - 101 |
| Publisher: IEEE |
| Full litterature document |
| |
|
| » A Puzzle-Based Defense Strategy Against Flooding Attacks Using Game Theory |
Abstract:
In recent years, a number of puzzle-based defense mechanisms have been proposed against flooding denial-of-service (DoS) attacks in networks. Nonetheless, these mechanisms have not been designed through formal approaches and thereby some important design issues such as effectiveness and optimality have remained unresolved. This paper utilizes game theory to propose a series of optimal puzzle-based strategies for handling increasingly sophisticated flooding attack scenarios. In doing so, the solution concept of Nash equilibrium is used in a prescriptive way, where the defender takes his part in the solution as an optimum defense against rational attackers. This study culminates in a strategy for handling distributed attacks from an unknown number of sources. |
| Autors: Fallah, Mehran; |
| Appeared in: IEEE Transactions on Dependable and Secure Computing |
| Publication date: Mar 2010, volume: 7, issue:1, pages: 5 - 19 |
| Publisher: IEEE |
| Full litterature document |
| |
|
| » A Rank-One Update Algorithm for Fast Solving Kernel Foley–Sammon Optimal Discriminant Vectors |
Abstract:
Discriminant analysis plays an important role in statistical pattern recognition. A popular method is the Foley–Sammon optimal discriminant vectors (FSODVs) method, which aims to find an optimal set of discriminant vectors that maximize the Fisher discriminant criterion under the orthogonal constraint. The FSODVs method outperforms the classic Fisher linear discriminant analysis (FLDA) method in the sense that it can solve more discriminant vectors for recognition. Kernel Foley–Sammon optimal discriminant vectors (KFSODVs) is a nonlinear extension of FSODVs via the kernel trick. However, the current KFSODVs algorithm may suffer from the heavy computation problem since it involves computing the inverse of matrices when solving each discriminant vector, resulting in a cubic complexity for each discriminant vector. This is costly when the number of discriminant vectors to be computed is large. In this paper, we propose a fast algorithm for solving the KFSODVs, which is based on rank-one update (ROU) of the eigensytems. It only requires a square complexity for each discriminant vector. Moreover, we also generalize our method to efficiently solve a family of optimally constrained generalized Rayleigh quotient (OCGRQ) problems which include many existing dimensionality reduction techniques. We conduct extensive experiments on several real data sets to demonstrate the effectiveness of the proposed algorithms. |
| Autors: Zheng, W.;Lin, Z.;Tang, X.; |
| Appeared in: IEEE Transactions on Neural Networks |
| Publication date: Mar 2010, volume: 21, issue:3, pages: 393 - 403 |
| Publisher: IEEE |
| Full litterature document |
| |
|
| » A Recursive Method for the Approximation of LTI Systems Using Subband Processing |
Abstract:
Using the subband technique, an LTI system can be implemented by the composition of an analysis filterbank, followed by a transfer matrix (subband model) and a synthesis filterbank. The advantage of this approach is that it offers a good tradeoff between latency and computational complexity. In this paper we propose an optimization method for approximating an LTI system using the subband technique. The proposed method includes optimal allocation of parameters from different FIR entries of the subband model, while keeping constant the total number of parameters, for a better utilization of the available coefficients. The optimization is done in a weighted least-squares sense considering either linear or logarithmic amplitude scale. Simulation results demonstrate the advantages of the proposed method when compared with classical implementation approaches using pole-zero transfer functions or segmented FFT algorithms. |
| Autors: Marelli, D.;Minyue Fu; |
| Appeared in: IEEE Transactions on Signal Processing |
| Publication date: Mar 2010, volume: 58, issue:3, pages: 1025 - 1034 |
| Publisher: IEEE |
| Full litterature document |
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|
| » A Response to “Room Temperature Single-Electron Transistor Featuring Gate-Enhanced on-State Current” |
Abstract:
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| Autors: Joyce, R. A.;Lee, Y.-c.;Orlov, A. O.;Snider, G. L.; |
| Appeared in: IEEE Electron Device Letters |
| Publication date: Mar 2010, volume: 31, issue:3, pages: 249 - 249 |
| Publisher: IEEE |
| Full litterature document |
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