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Single-trial analysis of cortical oscillatory activities during voluntary movements using empirical mode decomposition (emd)-based spatiotemporal approach

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Annals of Biomedical engineering 2009年第8期37卷 1683-1700页

作者： Lee, Po-Lei Shang, Li-Zen Wu, Yu-Te Shu, Chih-Hung Hsieh, Jen-Chuen Lin, Yung-Yang Wu, Chi-Hsun Liu, Yu-Lu Yang, Chia-Yen Sun, Chia-Wei Shyu, Kuo-Kai Department of Electrical Engineering National Central University No. 300 Jhongda Rd. Jhongli City Taoyuan County 32001 Taiwan Integrated Brain Research Laboratory Department of Medical Research and Education Taipei Veterans General Hospital Taipei Taiwan Institute of Brain Science National Yang-Ming University Taipei Taiwan Institute of Radiological Science National Yang-Ming University Taipei Taiwan Department of Otolaryngology Taipei Veterans General Hospital Taipei Taiwan National Yang-Ming University School of Medicine Taipei Taiwan Center for Neuroscience National Yang-Ming University Taipei Taiwan Neurological Institute Taipei Veterans General Hospital Taipei Taiwan Institute of Computer Communication and System Engineering Ching-Yun University Taoyuan Taiwan Biophotonics Interdisciplinary Research Center National Yang-Ming University Taipei Taiwan Institute of Biophotonics National Yang-Ming University Taipei Taiwan

This study presents a method based on empirical mode decomposition (EMD) and a spatial template-based matching approach to extract sensorimotor oscillatory activities from multi-channel magnetoencephalographic (MEG) measurements during right index finger lifting. The longitudinal gradiometer of the sensor unit which presents most prominent SEF was selected on which each single-trial recording was decomposed into a set of intrinsic mode functions (IMFs). The correlation between each IMF of the selected channel and raw data on other channels were created and represented as a spatial map. The sensorimotor-related IMFs with corresponding correlational spatial map exhibiting large values on primary sensorimotor area (SMI) were selected via spatial-template matching process. Trial-specific alpha and beta bands were determined in sensorimotor-related oscillatory activities using a two-spectrum comparison between the spectra obtained from baseline period (-4 to -3 s) and movement-onset period (-0.5 to 0.5 s). Sensorimotor-related oscillatory activities were filtered within the trial-specific frequency bands to resolve task-related oscillatory activities. Results demonstrated that the optimal phase and amplitude information were preserved not only for alpha suppression (event-related desynchronization) and beta rebound (event-related synchronization) but also for profound analysis of subtle dynamics across trials. The retention of high SNR in the extracted oscillatory activities allow various methods of source estimation that can be applied to study the intricate brain dynamics of motor control mechanisms. The present study enables the possibility of investigating cortical pathophysiology of movement disorder on a trial-by-trial basis which also permits an effective alternative for participants or patients who can not endure lengthy procedures or are incapable of sustaining long experiments. © 2009 Biomedical engineering Society.

关键词： Intrinsic mode functions

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Comparison of rotary cement kiln identified models

Comparison of rotary cement kiln identified models

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International Conference on control and Automation (ICCA)

作者： G. Noshirvani A. Fatehi B. Araabi M. Shirvani M. Azizi ACER Markaz Branch Arak Iran Advanced Process Automation & Control Research group Electrical Engineering Department K.N. Toosi University of Technology Tehran Iran Control and Intelligent Processing Center of Excellence Electrical and Computer Engineering Department University of Tehran Tehran Iran Chemical Engineering Department and member of Cement Research Center University of Science and Technology Tehran Iran Saveh Cement Company Saveh Iran

Rotary cement kiln is the main part of a cement plant that clinker is produced in it. Clinker is the main ingredient of cement. Continual and prolonged operation of rotary cement kiln is vital in cement factories. However, prolonged operation of the kiln is not possible and periodic repairs of the refractory lining would become necessary, due to non-linear phenomena existing in the kiln, such as sudden falls of coatings in the burning zone and probability of damages to the refractory materials during production. This is the basic reason behind the needs for a comprehensive model which is severely necessary for better control of this process. Such a model can be derived based on the mathematic analysis with consultation of expert operator experiences. In this paper both linear and nonlinear model are identified for rotary kiln of Saveh white cement factory. The linear model is introduced using Box-Jenkins structure. The results of the obtained model were satisfactory compared to some other linear models and can be used for designing adaptive or robust controllers. Also, nonlinear system identification via Neural Network technique is performed and its result was compared to linear models.

关键词： Kilns Production facilities Coatings Building materials Process control Mathematical model Mathematics Programmable control Adaptive control Robust control

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Impedance model force control using neural networks for a desktop NC machine tool

Impedance model force control using neural networks for a de...

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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Fusaomi Nagata Takanori Mizobuchi Shintaro Tani Keigo Watanabe Tetsuo Hase Zenku Haga Maki K. Habib Department of Electronics and Computer Science Tokyo University of Science Sanyo-Onoda Yamaguchi Japan Research and Development Center Meiho Company Limited Nogata Japan Department of Advanced Systems Control Engineering Graduate School of Science and Engineering Saga University Saga Japan Mechanical Engineering Department School of Sciences and Engineering American University Cairo Cairo Egypt

In manufacturing industries of metallics molds, various NC machine tools are used. We have already proposed a desktop NC machine tool with compliance control capability to automatically cope with the finishing process of LED lens molds. The NC machine tool has an ability to control the polishing force acting between an abrasive tool and workpiece. The force control method is called impedance model force control. The most important gain is the desired damping of the impedance model. Ideally, the desired damping is calculated from the critical damping condition in consideration of the effective stiffness in force control system. However, one of the serious problems is that the effective stiffness of the NC machine tool has undesirable nonlinearity. The nonlinearity gives bad influences to the force control stability. In this paper, a fine tuning method of the desired damping is considered by using neural networks. The neural networks acquire the nonlinearity of effective stiffness. It has been observed that the desired damping generated from the learned neural networks allows the NC machine tool to achieve a stable finishing result.

关键词： Impedance Force control Neural networks computer numerical control Damping automatic control Finishing Manufacturing industries Light emitting diodes Lenses

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RTS-like fluctuation in Gate Induced Drain Leakage current of Saddle-Fin type DRAM cell transistor

RTS-like fluctuation in Gate Induced Drain Leakage current o...

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International Electron Devices Meeting (IEDM)

作者： Heesang Kim Kyungdo Kim Tae-Kyung Oh Seon-Yong Cha Sung-Joo Hong Sung-Wook Park Hyungcheol Shin School of Electrical Engineering and Computer Science Inter university Semiconductor Research Center (ISRC) Seoul National University Seoul South Korea Research and Development Division Hynix Semiconductor Inc. Icheon Gyeonggi South Korea

ISBN: (纸本)9781424456390;9781424456406

RTS (random telegraph signal)-like fluctuation in Gate Induced Drain Leakage (GIDL) current of Saddle-Fin (S-Fin) type DRAM cell transistor was investigated for the first time. Furthermore, two types of fluctuation which have apparently different ¿ high (average time duration of high leakage state) to ¿ low (average time duration of low leakage state) ratio were investigated, and it was found that the energy difference between bistable levels is similar to that of the junction leakage.

关键词： Fluctuations Leakage current Random access memory Current measurement Time measurement Telegraphy Voltage research and development Monitoring Frequency domain analysis

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Mobility assisted localization for robotic sensor networks

Mobility assisted localization for robotic sensor networks

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International Conference on Information and Automation (ICIA)

作者： Changhua Wu Weihua Sheng Ying Zhang Saroja Kanchi Department of Computer Science Kettering University Flint MI USA School of Electrical and Computer Engineering Oklahoma State University Stillwater OK USA Palo Alto Research Center Inc.orporated Palo Alto CA USA

The accurate localization of sensor nodes in a mobile robotic sensor network is important in many surveillance applications. Based on our previous work in sensor localization, this paper introduces a mobility assisted localization approach guided by network rigidity for mobile robotic sensor networks. The rigidity test of a network is based on a pebble game algorithm, that decides whether the network is uniquely localizable or not. If its local network is not uniquely localizable, the mobile node circles around its original position to collect at least two extra ranging data with each of its neighbors while recording its trajectory using odometer. We prove that the extra data with robot trajectory will make the local network uniquely localizable. The local maps of all the nodes are then merged into a globally consistent map. We evaluate the effectiveness of the proposed approach using two examples of low-degree networks and four types of topologically different networks.

关键词： Mobile robots Robot sensing systems Intelligent sensors Robotics and automation Surveillance Wireless sensor networks Monitoring Intelligent transportation systems Intelligent networks Time measurement

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A novel load variation compensation algorithm in a sensor-less brushless DC motor drive for a reciprocating compressor

A novel load variation compensation algorithm in a sensor-le...

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International Conference on Telecommunications Energy (INTELEC)

作者： Sang-Taek Lee Hee-Jun Kim Dae-Kyong Kim Kwang-Woon Lee Dept. of Electronics Electrical Control and Instrumentation Engineering Hanyang Univ. Korea Digital Convergence Center Korea Electronics Technology Institute Korea School of Electrical Engineering and Computer Science Hanyang Univ. Korea Division of Maritime Electronics and Communication Engineering Mokpo National Maritime Univ. Korea

ISBN: (纸本)9781424424900

This paper presents a novel load variation compensation algorithm in a sensor-less BLDC motor drive for a reciprocating compressor. Periodic load variation of a reciprocating compressor leads to commutation position error and instantaneous speed variation and causes large peak currents. The major concept of this study includes tracking the pattern of load torque and controlling the motor input voltage by the commutation point and PWM depending on the tracked load torque. The suggested method can reduce the cost because this method does not require additional current sensing or voltage comparison circuit. The utility of the suggested algorithm was confirmed by simulation and experimental results of a sensor-less BLDC motor drive.

关键词： Load management Brushless DC motors Torque Commutation Pistons Voltage control Refrigeration Rotors Home appliances Force control

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THz spectroscopic estimation of water content in human articular cartilage

THz spectroscopic estimation of water content in human artic...

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International Conference on Infrared and Millimeter Waves

作者： E. Jung H. Park H. Han S. Kim I. Park H. Lim J. Cui B. Min Department of Electrical and Computer Engineering Pohang University of Science and Technology Pohang South Korea Center of THz Research Rensselaer Polytechnic Institute Troy NY USA Department of Electrical and Computer Engineering Ajou University Suwon South Korea Department of Orthopedic Surgery School of Medicine Ajou University Suwon South Korea

ISBN: (纸本)9781424454167

Water distribution of human osteoarthritic articular cartilage has been characterized using terahertz time domain spectroscopy. The evaluation of water content in cartilage tissue can be helpful to diagnose the early degenerative joint diseases. The estimated water content in our measurement decreases along the depth of the cartilage tissue and shows a good agreement with the previous results acquired by destructive biochemical methods.

关键词： Spectroscopy Humans Absorption Frequency Bones Joints Magnetic resonance imaging Osteoarthritis Orthopedic surgery Medical diagnostic imaging

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Orthogonal-type robot with a CAD/CAM-based position/force controller

Orthogonal-type robot with a CAD/CAM-based position/force co...

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IEEE Symposium on Computational Intelligence in control and Automation, CICA

作者： Fusaomi Nagata Shintaro Tani Takanori Mizobuchi Tetsuo Hase Zenku Haga Masaaki Omoto Keigo Watanabe Department of Electronics and Computer Science Tokyo University of Science Yamaguchi Japan Research and Development Center Meiho Company Limited Nogata Japan R&D Center Meiho Co. Ltd. Nogata Department of Advanced Systems Control Engineering Graduate School of Science and Engineering Saga University Saga Japan

In this paper, a new desktop orthogonal-type robot with a CAD/CAM-based position/force controller is presented for finishing small metallic molds with curved surface. The robot consists of a three-axis robot whose single one has a high position accuracy of 1 mum, which means that it can perform higher resolutions of position and force, compared to general industrial robots. A thin wood stick tool with a ball-end tip is attached to the z-axis through a force sensor. The control system of the robot is comprised of a force feedback loop, position feedback loop and position feedforward loop. The force feedback loop controls the polishing force consisting of tool contact force and kinetic friction forces. The position feedback loop controls the position in pick feed direction. Further, the position feedforward loop leads the tool tip along a spiral path. We first evaluate the backlash that causes inaccuracy in position at the tip of the abrasive tool, by simply measuring the position and force. Next, a surface following control experiment along a lens mold is conducted, in which the mold has axis-symmetric concave areas. Finally, a LED lens mold is further finished by using the proposed system in order to demonstrate the performance and promise.

关键词： Force control Service robots Force sensors Force feedback Robot sensing systems Feedback loop Force measurement Lenses Surface finishing electrical equipment industry

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An automatic computer-aided detection system for meniscal tears on magnetic resonance images

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IEEE Transactions on Medical Imaging 2009年第8期28卷 1308-1316页

作者： Ramakrishna, Bharath Liu, Weimin Saiprasad, Ganesh Safdar, Nabile Chang, Chein-I Siddiqui, Khan Kim, W. Siegel, Eliot Chai, Jyh-Wen Chen, Clayton Chi-Chang Lee, San-Kan Remote Sensing Signal and Image Processing Laboratory Department of Computer Science and Electrical Engineering University of Maryland Baltimore MD 21250 United States University of Maryland School of Medicine Baltimore MD 21201 United States Department of Electrical Engineering and Environmental Restoration Disaster Reduction Research Center National Chung Hsing University Taichung 402 Taiwan VA Maryland Health Care System Baltimore MD 21201 United States Hospital of the University of Pennsylvania Philadelphia PA 19104 United States Department of Radiology College of Medicine China Medical University Taichung 404 Taiwan Department of Radiology Taichung Veterans General Hospital Taichung 40705 Taiwan Department of Radiological Technology Central Taiwan University of Science and Technology Taichung 406 Taiwan Department of Radiology Taichung Veterans General Hospital Taichung 407 Taiwan

Knee-related injuries including meniscal tears are common in both young athletes and the aging population, and require accurate diagnosis and surgical intervention when appropriate. With proper techniques and radiologists' experienced skills, confidence in detection of meniscal tears can be quite high. This paper develops a novel computer-aided detection (CAD) diagnostic system for automatic detection of meniscal tears in the knee. Evaluation of this CAD system using an archived database of images from 40 individuals with suspected knee injuries indicates that the sensitivity and specificity of the proposed CAD system are 83.87% and 75.19%, respectively, compared to the mean sensitivity and specificity of 77.41% and 81.39%, respectively, obtained by experienced radiologists in routine diagnosis without using the CAD. The experimental results suggest that the developed CAD system has great potential and promise in automatic detection of both simple and complex meniscal tears of the knee. © 2009 IEEE.

关键词： Magnetic resonance imaging

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Quantum algorithm for approximating partition functions

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Physical Review A 2009年第2期80卷 022340-022340页

作者： Pawel Wocjan Chen-Fu Chiang Daniel Nagaj Anura Abeyesinghe School of Electrical Engineering and Computer Science University of Central Florida Orlando Florida 32816 USA Research Center for Quantum Information Institute of Physics Slovak Academy of Sciences Dúbravská Cesta 9 84215 Bratislava Slovakia Quniverse Líščie Údolie 116 84104 Bratislava Slovakia

We present a quantum algorithm based on classical fully polynomial randomized approximation schemes (FPRASs) for estimating partition functions that combine simulated annealing with the Monte Carlo Markov chain method and use nonadaptive cooling schedules. We achieve a twofold polynomial improvement in time complexity: a quadratic reduction with respect to the spectral gap of the underlying Markov chains and a quadratic reduction with respect to the parameter characterizing the desired accuracy of the estimate output by the FPRAS. Both reductions are intimately related and cannot be achieved separately. First, we use Grover’s fixed-point search, quantum walks, and phase estimation to efficiently prepare approximate coherent encodings of stationary distributions of the Markov chains. The speed up we obtain in this way is due to the quadratic relation between the spectral and phase gaps of classical and quantum walks. The second speed up with respect to accuracy comes from generalized quantum counting used instead of classical sampling to estimate expected values of quantum observables.

关键词： Simulated annealing

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