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IEEE Symposium (IUS) Ultrasonics

作者： Jiujiang Wang Yuanyu Yu Sio Hang Pun Peng Un Mak U Kin Che Ching-Hsiang Cheng Mang I Vai Department of Electrical and Computer Engineering University of Macau Macau State Key Laboratory of Analog and Mixed-Signal VLSI University of Macau Macau Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong

ISBN: (纸本)9781467398985

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a new type of ultrasound wave generator and detector. Analytical method is intuitive to understand the mechanism and physical effects through modeling of CMUT. To optimize the design procedures of CMUT membrane undergoing large deflection, a new analytical model with the consideration of the lateral force using Von Kármán equations is proposed. This model is capable of calculating the membrane profile of the CMUT since it includes the effect of the lateral force. The calculated results match well with the simulated results and the maximum deflection error in the center of the CMUT is less than 1% of the simulation results. The lateral force increases with the deflection of the membrane and it can be found that with the introduction of the lateral force, the proposed model can accurately estimate the membrane large defection profile in both single and double-layer membrane cases. The capacitance of the CMUT can be derived when the deflection profile of the membrane is available.

关键词： Mathematical model Force Electrodes Analytical models Finite element analysis Micromechanical devices Computational modeling

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Ultrasonic reflectivity function estimation using Cepstrum Sparse Deconvolution

Ultrasonic reflectivity function estimation using Cepstrum S...

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IEEE International Ultrasonics Symposium

作者： Juan Lu Ramazan Demirli Jafar Saniie Embedded Computing and Signal Processing Laboratory Department of Electrical and Computer Engineering Illinois Institute of Technology Chicago United States Center for Advanced Communications Villanova University Pennsylvania United States

ISBN: (纸本)9781467398985

The ultrasonic signals backscattered from multilayered materials using a pulse-echo method are inherently low-resolution due to the band-limited nature of the interrogating transducer. To improve resolution, the Wiener Filter (WF) based solutions have been used traditionally, although they provide limited improvement and are highly sensitive to noise. More recently, sparse deconvolution techniques (e.g., l1-regularized Least Squares Deconvolution (l1-LSD)) have proved to be effective in improving the resolution;however, they are highly dependent on pulse invariance. It is common for an ultrasonic wavelet to change its shape as it propagates through the materials due to frequency dependent attenuation, scattering and dispersion. Consequently, these changes in pulse shape limit the application of these algorithms which need a prior knowledge of pulse-wave of the system. In this paper we present an adaptive and highly efficient deconvolution technique, Cepstrum Sparse Deconvolution (CSD), which does not require any prior information of the system or the detected object but compensates for the pulse-wave variation by estimating the fundamental pulse-wave shape directly from the backscattered signal. This pulse-wave estimation is based on cepstrum processing of the signal prior to the deconvolution process. Applications and comparisons are made to evaluate the performance of CSD, WF and l1-LSD through experimental and simulated ultrasound data which contain varying-shape wavelets with respect to amplitude, center frequency, arrival time, bandwidth, and phase parameters. The Normalized Mean Absolute Score (NMAS) index, a measure of distance between the actual reflectivity function and the estimated function is used to evaluate these algorithms' performance. The results show that CSD is the fastest algorithm and offers highest resolution among these three algorithms even though the pulse-wave may have gone through a significant change.

关键词： l1-LSD Sparse Deconvolution Cepstrum Processing Wiener Filter

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Existence and switching behavior of bright and dark kerr solitons in whispering-gallery mode resonators with zero group-velocity dispersion

arXiv

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arXiv 2017年

作者： Talla Mbé, Jimmi H. Milián, Carles Chembo, Yanne K. Laboratory of Electronics Automation and Signal Processing Department of Physics University of Dschang P.O. Box 67 Dschang Cameroon Laboratory of Modelling and Simulation in Engineering Biomimetics and Prototypes Department of Physics University of Yaoundé I P. O. Box 812 Yaoundé Cameroon Polytechnic School of Yaoundé P.O. Box 8390 Yaoundé Cameroon Centre de Physique Théorique CNRS Ecole Polytechnique PalaiseauF-91128 France Optics Department FEMTO-ST Institute CNRS & Univ. Bourgogne-Franche-Comté 15B Avenue des Montboucons Besançon Cedex25030 France Atlanta Mirror Lab School of Electrical and Computer Engineering 777 Atlantic Dr NW AtlantaGA30332-0250 United States

We use the generalized Lugiato-Lefever model to investigate the phenomenon of Kerr optical frequency comb generation when group-velocity dispersion is null. In that case, the first dispersion term that plays a leading role is third-order dispersion. We show that this term is sufficient to allow for the existence of both bright and dark solitons. We identify the areas in the parameter space where both kind of solitons can be excited inside the resonator. We also unveil a phenomenon of hysteretic switching between these two types of solitons when the power of the pump laser is cyclically varied. Copyright © 2017, The Authors. All rights reserved.

关键词： Group velocity dispersion

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Author Correction: Why rankings of biomedical image analysis competitions should be interpreted with care

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Nature communications 2019年第1期10卷 588页

作者： Lena Maier-Hein Matthias Eisenmann Annika Reinke Sinan Onogur Marko Stankovic Patrick Scholz Tal Arbel Hrvoje Bogunovic Andrew P Bradley Aaron Carass Carolin Feldmann Alejandro F Frangi Peter M Full Bram van Ginneken Allan Hanbury Katrin Honauer Michal Kozubek Bennett A Landman Keno März Oskar Maier Klaus Maier-Hein Bjoern H Menze Henning Müller Peter F Neher Wiro Niessen Nasir Rajpoot Gregory C Sharp Korsuk Sirinukunwattana Stefanie Speidel Christian Stock Danail Stoyanov Abdel Aziz Taha Fons van der Sommen Ching-Wei Wang Marc-André Weber Guoyan Zheng Pierre Jannin Annette Kopp-Schneider Division of Computer Assisted Medical Interventions (CAMI) German Cancer Research Center (DKFZ) 69120 Heidelberg Germany. l.maier-hein@dkfz.de. Division of Computer Assisted Medical Interventions (CAMI) German Cancer Research Center (DKFZ) 69120 Heidelberg Germany. Centre for Intelligent Machines McGill University Montreal QC H3A0G4 Canada. Christian Doppler Laboratory for Ophthalmic Image Analysis Department of Ophthalmology Medical University Vienna 1090 Vienna Austria. Science and Engineering Faculty Queensland University of Technology Brisbane QLD 4001 Australia. Department of Electrical and Computer Engineering Department of Computer Science Johns Hopkins University Baltimore MD 21218 USA. CISTIB - Center for Computational Imaging & Simulation Technologies in Biomedicine The University of Leeds Leeds Yorkshire LS2 9JT UK. Department of Radiology and Nuclear Medicine Medical Image Analysis Radboud University Center 6525 GA Nijmegen The Netherlands. Institute of Information Systems Engineering TU Wien 1040 Vienna Austria. Complexity Science Hub Vienna 1080 Vienna Austria. Heidelberg Collaboratory for Image Processing (HCI Heidelberg University 69120 Heidelberg Germany. Centre for Biomedical Image Analysis Masaryk University 60200 Brno Czech Republic. Electrical Engineering Vanderbilt University Nashville TN 37235-1679 USA. Institute of Medical Informatics Universität zu Lübeck 23562 Lübeck Germany. Division of Medical Image Computing (MIC) German Cancer Research Center (DKFZ) 69120 Heidelberg Germany. Institute for Advanced Studies Department of Informatics Technical University of Munich 80333 Munich Germany. Information System Institute HES-SO Sierre 3960 Switzerland. Departments of Radiology Nuclear Medicine and Medical Informatics Erasmus MC 3015 GD Rotterdam The Netherlands. Department of Computer Science University of Warwick Coventry CV4 7AL UK. Department of Radiation Oncology Massachusetts General Hospital Boston MA

In the original version of this Article the values in the rightmost column of Table 1 were inadvertently shifted relative to the other columns. This has now been corrected in the PDF and HTML versions of the Article.

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Ground Maneuvering Target Imaging and High-Order Motion Parameter Estimation Based on Second-Order Keystone and Generalized Hough-HAF Transform

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IEEE Transactions on Geoscience and Remote Sensing 2016年第99期PP卷

作者： Huang, Penghui Liao, Guisheng Yang, Zhiwei Xia, Xiang-Gen Ma, Jingtao Zheng, Jibin National Laboratory of Radar Signal Processing Xidian University Xian710071 China Department of Electrical and Computer Engineering University of Delaware NewarkDE19716 United States Shanghai Engineering Center for Microsatellites Shanghai201203 China

This paper proposes a new method to focus a ground moving target with complex motions and estimate its motion parameters in a synthetic aperture radar (SAR) system. In this method, the second-order Keystone transform is applied to correct the range curvature. Then, the Hough transform is applied to estimate the slope of the range walk trajectory, from which the target cross-track velocity is obtained. Finally, a generalized Hough-high-order ambiguity function (GHHAF) transform is applied to transform the target signal into a 2-D time-frequency plane and estimate its slope associated with the third-order Doppler parameter. Compared with the conventional SAR imaging methods using the second-order phase model, the proposed method can obtain better imaging quality since the third-order Doppler frequency migration is effectively eliminated. Both simulated and real data processing results are provided to validate the effectiveness of the proposed algorithm. © 2016 IEEE.

关键词： Parameter estimation

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An accurate design to calculate and measure the capacitance of CMUT for pressure sensors

An accurate design to calculate and measure the capacitance ...

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IEEE ICCE-China Workshop (ICCE-China)

作者： Jiujiang Wang Yuanyu Yu Sio Hang Pun Yueming Gao U Kin Che Peng Un Mak Department of Electrical and Computer Engineering University of Macau Macau State Key Laboratory of Analog and Mixed-Signal VLSI University of Macau Macau Key Lab of Medical Instrumentation & Pharmaceutical Technology of Fujian Province Fuzhou China

ISBN: (纸本)9781509061945

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a type of micro-electro-mechanical system (MEMS) device which has the advantages such as ease of integration with front-end electronics and fabrication of uniform device arrays. The structure and fundamental working principle of a CMUT are similar to that of a parallel plate capacitor. When working in conventional mode, the deflection profiles can be described by analytical expressions and the capacitance can be calculated thereafter. A design was proposed to calculate the deflection profiles of the CMUT membrane accurately and eliminate the parasitic capacitance of the CMUT device. By appropriately selecting the dimensions of the device, the CMUT can be used as a pressure sensor.

关键词： Capacitance Capacitance measurement Pressure measurement Electrodes Pressure sensors Substrates Fabrication

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Long-Time Coherent Integration for Weak Maneuvering Target Detection and High-Order Motion Parameter Estimation Based on Keystone Transform

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IEEE Transactions on signal Processing 2016年第15期64卷 4013-4026页

作者： Huang, Penghui Liao, Guisheng Yang, Zhiwei Xia, Xiang-Gen Ma, Jing-Tao Ma, Jingting National Laboratory of Radar Signal Processing Xidian University Xi'an710071 China Department of Electrical and Computer Engineering University of Delaware NewarkDE19716 United States Shanghai Engineering Center for Micro-Satellites Shanghai201203 China Beijing Huahang Radio Measurement Institute Beijing100013 China

In the airborne or spaceborne radar applications, prolonging the coherent integration time is one of the effective methods to improve the radar detection ability of a weak maneuvering target, whereas the coherent integration performance may degrade due to the complex range migration (RM) and Doppler frequency migration (DFM) effects. In this paper, detection and motion parameter estimation for a weak maneuvering target with the third-order RM and DFM are considered. Firstly, Keystone transform is applied to compensate the linear range walk. Then, the matched filtering processing is performed in the range-frequency and azimuth-time domain to eliminate the residual coupling effects between range and azimuth. Finally, a well-focused image of a moving target is obtained, and three motion parameters, i.e., velocity, acceleration, and acceleration rate, are effectively estimated. In addition, as for a fast-moving target with Doppler ambiguity, two cases, i.e., target azimuth spectrum within a pulse repetition frequency (PRF) and spanning over neighboring PRF bands, are analyzed. Compared with the generalized Radon Fourier transform (GRFT), the proposed method can acquire a close integration performance but with lower computational complexity since the parameter searching dimension is reduced. Simulated processing results are provided to validate the effectiveness of the proposed method. © 1991-2012 IEEE.

关键词： Space-based radar

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On the Ergodic Capacity of Multiple Antenna Cognitive Satellite Terrestrial Networks

On the Ergodic Capacity of Multiple Antenna Cognitive Satell...

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Ad-Hoc and Sensor Networks Symposium

作者： Kang An Min Lin Tao Liang Jian Ouyang Wei-Ping Zhu College of Communications Engineering PLA University of Science and Technology National Mobile Communications Research Laboratory Southeast University Nanjing Institute of Telecommunication Technology Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Department of Electrical and Computer Engineering Concordia University

ISBN: (纸本)9781479966653

The integration of cognitive radio (CR) into satellite networks is recognized as an effective strategy to enhance the efficiency of radio spectrum. This paper investigates the ergodic capacity of a multiple antenna cognitive satellite terrestrial network, where the secondary terrestrial system can coexist with the primary satellite system as long as the interference imposed from the secondary user (SU) to the primary user (PU) is below a predefined threshold. Specifically, the Meijer-G function based analytical expression for the ergodic capacity of the secondary network is derived, which not only provides an efficient means to evaluate the system performance but also characterize the impact of various channel parameters on the network. Finally, simulation results are provided to demonstrate the validity of the theoretical analysis.

关键词： Cognitive satellite terrestrial network Multiple antenna Ergodic capacity

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An 8-bit 0.7-GS/s single channel flash-SAR ADC in 65-nm CMOS technology

An 8-bit 0.7-GS/s single channel flash-SAR ADC in 65-nm CMOS...

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European Conference on Solid-State Circuits (ESSCIRC)

作者： Dante Gabriel Muratore Alper Akdikmen Edoardo Bonizzoni Franco Maloberti U-Fat Chio Sai-Weng Sin Rui Paulo Martins Department of Electrical Computer and Biomedical Engineering University of Pavia Pavia Italy State-Key Laboratory of Analog and Mixed Signal VLSI University of Macau Macau China Instituto Superior Técnico Universidade de Lisboa Lisbon Portugal

This paper presents the prototype of a single channel 8-bit 0.7-GS/s A/D converter implemented in a 65-nm CMOS process. The required thresholds are generated from the resistive interpolation embedded within the preamplifier preceding the latches. The active area of the chip is 150 × 220 μm 2 and the total power consumption is 5.96 mW. At Nyquist, the ADC achieves 6.62 ENOB, resulting in a figure of merit equal to 86.7 fJ/conversion-step.

关键词： Frequency measurement Latches Voltage measurement Calibration Clocks Power demand Semiconductor device measurement

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Investigation of residual Ag amount into human body using Ag/AgCl electrodes during IBC

Investigation of residual Ag amount into human body using Ag...

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IEEE ICCE-China Workshop (ICCE-China)

作者： Xiang Tang Xi Mei Chen Peng Un Mak Yueming Gao Mang I Vai Department of Electrical and Computer Engineering University of Macau Macau China State Key Laboratory of Analog and Mixed Signal VLSI University of Macau Macau China Key Lab of Medical Instrumentation & Pharmaceutical Technology of Fujian Province Fuzhou China

ISBN: (纸本)9781509061945

The silver/silver chloride (Ag/AgCl) electrode is a widely-used electrode type for signal stimulation and detection in many groups during their Intra-body communication (IBC) investigations. Silver ions may reside in the human body during the IBC process. This may cause argyria and argyrosis due to the accumulation over time. In this article, IBC pseudo-experiments of signal stimulation and detection by using Ag/AgCl electrodes are designed and conducted to measure the amount of silver ion residue. For the sake of safety and simplicity, physiological saline is used instead of the human in the experiments. The stimulation and detection experiments in galvanic coupling method as well as the capacitive coupling method show that there exists silver ion residual. Although the amount of the silver ion residue is remained within the safety standard in each experiment, it may be not safe by using the Ag/AgCl electrodes frequently.

关键词： Electrodes Silver Ions Couplings Skin Physiology Attenuation

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