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IEEE/SICE International Symposium on System Integration

作者： Tae-Il Kim Wook Bahn Changhun Lee Tae-jae Lee Muhammad Muneeb Shaikh Kwang-soo Kim Automation and Systems Research Institute (ASRI) and School of Electrical Engineering and Computer Science Seoul National University Seoul South Korea Department of Control and Instrumentation Engineering Hanbat National University Daejeon South Korea

This paper presents a vision-tracking for mobile robots, which tracks a moving target based on robot motion and stereo vision information. The proposed system controls pan and tilt actuators attached to a stereo camera, using the data from a gyroscope, robot wheel encoders, pan and tilt actuator encoders, and the stereo camera. Using this proposed system, the stereo camera always faces the moving target. The developed system calculates the angles of the pan and tilt actuators by estimating the relative position of the target with respect to the position of the robot. The developed system estimates the target position using the robot motion information and the stereo vision information. The movement of the robot is modeled as the transformation of the frame, which consists of a rotation and a translation. The developed system calculates the rotation using 3-axis gyroscope data and the translation using robot wheel encoder data. The proposed system measures the position of the target relative to the robot, combining the encoder data of pan and tilt actuators and the disparity map of the stereo vision. The inevitable mismatch of the data, which occurs from the asynchrony of the multiple sensors, is prevented by the proposed system, which compensates for the communication latency and the computation time. The experimental results show that the developed system achieves excellent tracking performance in several motion scenarios, including combinations of straights and curves and climbing of slopes.

关键词： Cameras Mobile robots Robot vision systems Actuators Instruction sets

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An improved KNN algorithm based on multi-attribute classification

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ICIC Express Letters, Part B: Applications 2011年第5期2卷 1117-1122页

作者： Zhang, Hongliang Li, Liangjun Li, Tienan Yang, Feng Computing Center of Anshan Normal University Anshan 114003 China School of Computer Science and Automatic Control Hebei United University No. 46 Xinhua Xidao Tangshan 063000 China School of Information Science and Engineering Northeastern University No. 11 Lane 3 Wenhua Road Heping District Shenyang 110819 China

To improve the classification accuracy of both the conventional Euclidean KNN algorithm and the improved KNN algorithm based on information entropy, this paper proposes an improved KNN algorithm based on multi-attribute classification. The procedures of the new algorithm comprise three steps: i) classify the attributes according to the percentage of their attribute values in an entire attribute of sample set into those discrete attributes suitable for entropy-based KNN algorithm and those continuous attributes suitable for conventional Euclidean KNN similarity-based algorithm;ii) process the two types of attributes separately and then sum up the two series of results with weighing and put the sum as the distance between samples;iii) select k samples which are closest to the test sample to determine the decision attribute type of the test sample. © 2011 ISSN 2185-2766.

关键词： Classification (of information)

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Investigations of Silicon Nano-crystal Floating Gate Memories

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MRS Online Proceedings Library (OPL) 2011年第1期638卷 F2.4.1-F2.4.1页

作者： Arvind Kumar Jeffrey J. Welser Sandip Tiwari Farhan Rana Kevin K. Chan IBM Thomas J. Watson Research Center P.O. Box 218 Yorktown Heights NY 10598 U.S.A School of Electrical Engineering Cornell University Ithaca NY 14853 Department of Electrical Engineering and Computer Science MIT Cambridge MA 02139

As memory continues to be scaled to ever smaller dimensions, the floating-gate memory transistor, which offers a single-element storage cell, becomes more attractive. Typically, this structure has been reserved for nonvolatile applications, where the comparatively high voltages, slow write speeds, and limited cyclability could be tolerated. However, if the floating-gate, which is usually a continuous film of polysilicon, is replaced with a discontinuous film of small floating islands (nano-crystals), a new set of tradeoffs in these performance factors becomes possible, opening the door to broader applications. If these islands are further reduced to the point where Coulomb charging or energy quantization effects become relevant, it is possible to control the charge on the islands at a single (or few) electron level, which offers very low power operation and may enable new functionality. This paper will discuss design and fabrication of these memories, experimental results on fabricated devices, and modeling of what could ultimately be achieved, as well as what limitations will ultimately be reached.

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Total variation regularization for bioluminescence tomography with an adaptive parameter choice approach

Total variation regularization for bioluminescence tomograph...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society

作者： Jinchao Feng Xiaowei Jia Kebin Jia Chenghu Qin Jie Tian College of Electronic Information & Control Engineering Beijing University of Technology School of Computer Science and Technology University of Science and Technology of China Intelligent Medical Research Center Institute of Automation Chinese Academy of Sciences

ISBN: (纸本)9781424441211

In this paper, we explore the application of total variation regularization method for bioluminescence tomography (BLT) with an adaptive regularization parameter choice approach. Since BLT is a seriously ill-posed problem, therefore, l_2 regularized methods are frequently adopted to recover the bioluminescent sources. However, l_2 regularized methods typically lead to smooth reconstructions. In this paper, we investigated the use of total variation (TV) regularization to improve the quality of BLT reconstruction. Furthermore, the regularization parameter in TV method was chosen adaptively to make the proposed algorithm more stable. Results on simulation data provide evidence that the reconstructed source can be localized accurately compared with l_2 method. Meanwhile, the effectiveness of utility of the parameter choice were illustrated. Finally, different levels of noisy data were added to validate the performance of the proposed algorithm.

关键词： Bioluminescence noisy data simulated data Tomography Television Self tuning Variation Reconstructive Surgical Procedures

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Compressive System Identification of LTI and LTV ARX Models

Compressive System Identification of LTI and LTV ARX Models

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IEEE Conference on Decision and control

作者： Borhan M. Sanandaji Tyrone L. Vincent Michael B. Wakin Roland Toth Kameshwar Poolla Department of Electrical Engineering and Computer Science Colorado School of Mines Golden CO 80401 USA Delft Center for Systems and Control Delft University of Technology Mekelweg 2 2628 CD Delft The Netherlands Departments of Electrical Engineering and Computer Sciences and Mechanical Engineering University of California Berkeley CA 94720 USA

ISBN: (纸本)9781612848006

In this paper, we consider identifying Auto Regressive with eXternal input (ARX) models for both Linear Time-Invariant (LTI) and Linear Time-Variant (LTV) systems. We aim at doing the identification from the smallest possible number of observations. This is inspired by the field of Compressive Sensing (CS), and for this reason, we call this problem Compressive System Identification (CSI). In the case of LTI ARX systems, a system with a large number of inputs and unknown input delays on each channel can require a model structure with a large number of parameters, unless input delay estimation is performed. Since the complexity of input delay estimation increases exponentially in the number of inputs, this can be difficult for high dimensional systems. We show that in cases where the LTI system has possibly many inputs with different unknown delays, simultaneous ARX identification and input delay estimation is possible from few observations, even though this leaves an apparently ill-conditioned identification problem. We discuss identification guarantees and support our proposed method with simulations. We also consider identifying LTV ARX models. In particular, we consider systems with parameters that change only at a few time instants in a piecewise-constant manner where neither the change moments nor the number of changes is known a priori. The main technical novelty of our approach is in casting the identification problem as recovery of a block-sparse signal from an underdetermined set of linear equations. We suggest a random sampling approach for LTV identification, address the issue of identifiability and again support our approach with illustrative simulations.

关键词： LTI System identification delay estimation Mathematic Identifiability Model structures

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A high Q design for N-channel wavelength division demultiplexer

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Journal of Optical Communications 2011年第4期32卷 211-216页

作者： Alipour-Banaei, Hamed Bahrami, Ali Nazari, Fakhreddin Rostami, Ali Department of Electronics Tabriz Branach Islamic Azad University Tabriz Iran Nanoptronics Research Center Electronics and Electrical Engineering Department Iran University of Science and Technology Tehran Iran Faculty of Electrical and Computer Engineering University of Tarbiat Modarres Tehran Iran Faculty of Electrical and Computer Engineering University of Tabriz Tabriz Iran School of Engineering-Emerging Technologies University of Tabriz Tabriz 51666 Iran

We present a new design for N-channel wavelength division demultiplexer using multistage multimode interference (MMI) structure. First, the general formulation for an N-channel demultiplexer in multimode area has been discussed. In this paper, we proposed a single parameter α for designing a demultiplexer with desired wavelengths, number of output channels and channel spacing. Then we simulated an 8-channel wavelength demultiplexer with high quality factor in the telecommunication range. The simulated structure shows 5 nm channel spacing and 2451 average quality factor. The excellent properties of this formulation are the high quality factor and its capability for choosing the desired number of output channels and channel spacing. The beam propagation method is used for simulation of the proposed device. Copyright © 2011 De Gruyter.

关键词： Beam propagation method

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Design of reference governor for a class of nonlinear systems with input constraints

Design of reference governor for a class of nonlinear system...

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International Conference on control, Automation and Systems ( ICCAS)

作者： Hyun Min Do Jin Young Choi Jin Ho Kyung Robotics and Mechatronics Research Center Korea Institute of Machinery and Materials Daejeon South Korea School of Electrical Engineering and Computer Science Seoul National University Seoul South Korea

This paper presents a design method of the reference governor for a class of nonlinear systems with input constraints. When the input has a constraint, the input saturation might happen and thus, the controller cannot work correctly. Furthermore, the output might diverge in the case of an open loop unstable system. To overcome this problem, a novel approach to the design of a reference governor is proposed. A nonlinear system diffeomorphic to a normal form is considered and additionally, a bounded disturbance in the control input is considered. In the proposed method, the behaviors of the states and input are predicted and the reference is modified so that the predicted input never exceeds the saturation limits and the modified one is closest to the given command among the values which are achievable without the input saturation. The convergence of the newly generated reference trajectory is proved and some simulation results are included to verify the performance of the proposed method.

关键词： Equations Trajectory Nonlinear systems Convergence Closed loop systems Safety Actuators

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Universal Steganalysis Based on Local Prediction Error in Wavelet Domain

Universal Steganalysis Based on Local Prediction Error in Wa...

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International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIHMSP)

作者： Anahita Shojaei-Hashemi Mostafa Mehdipour-Ghazi Shahrokh Ghaemmaghami Hamid Soltanian-Zadeh School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran Electronics Research Institute Sharif University of Technology Tehran Iran Image Analysis Laboratory Department of Radiology Henry Ford Health System Detroit MI USA Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran

A passive universal image steganalysis method is proposed that is shown to be of higher detection accuracy than existing truly blind steganalysis methods including Farid's and the WAM. This is achieved by improving some weaknesses of Farid's steganalysis scheme in feature extraction, that is, instead of deriving an over-determined equation system for each sub band of the wavelet decomposition, the sub bands are divided into overlapping blocks and an over-determined equation system is constructed for each block. To guarantee the existence of finite answers, the over-determined equation systems are solved in a way different from Farid's by using Moore-Penrose pseudo-inverse concept. Further improvement to the performance is achieved by adding diagonal directions and increasing the number of moments. The comparative evaluations confirm the superiority of the proposed method over prevalent blind steganalysis schemes.

关键词： Equations Mathematical model Payloads Transform coding Correlation Educational institutions Reliability

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Developing an automatic method for separation of arteries from veins in retinal images

Developing an automatic method for separation of arteries fr...

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International eConference on computer and Knowledge engineering (ICCKE)

作者： G. Mirsharif F. Tajeripour F. Sobhanmanesh H. Pourreza T. Banaee School of Electrical and Computer Engineering Shiraz University Shiraz Iran Computer Engineering Department Ferdowsi University of Mashhad Mashhad Iran Ophthalmic Research Center Khatam-Al-Anbia Hospital Medical Science University of Mashhad Mashhad Iran

Analyzing the retinal blood vessels can provide very helpful information to doctors for early detection of diseases such as diabetic retinopathy due to large number of patients. These diseases affect Blood vessels differently leading to thinner veins, thicker arteries or vice versa. Hence an abnormal width ratio of artery to vein (AVR) may be a sign of infection. To examine each class of blood vessels or measuring AVR, arteries and veins should be separated carefully. There have been a few researches done for classification of retinal Blood vessels up to this time. Some of their results are not comparable due to small and non standard databases used for evaluation of the respective methods. In this paper we focus to study appearance of vessels in different color spaces such as RGB and HSL to extract best features from inner and outer parts of vessels for classification of retinal blood vessels particularly the major ones. Since most of consecutive points in a vessel segments have similar features and these points belong to same type of vessel we attempt to divide long vessel segments into smaller ones and extract features for each vessel segment instead of every centerline points. Evaluating our method on DRIVE database we achieve 86% recognition rate on major vessels and 87.58% on pair main vessels in upper and lower region of retinal images, using a few sample points and a small feature set which decrease calculations noticeably. This work can help for future automatic tracking based methods to classify the smaller vessels or for determining the A/V ratio in major vessels.

关键词： Feature extraction Arteries Veins Image segmentation Retina Databases Image color analysis

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Average current mode control in digitally controlled discontinuous-conduction-mode PFC rectifier for improved line current distortion

Average current mode control in digitally controlled discont...

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Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC)

作者： Jong-Won Shin Bo-Hyung Cho Jae-Ho Lee School of Electric Engineering and Computer Science Seoul National University Seoul South Korea EV Control Central Research and Development Center LS Industrial System Anyang South Korea

This paper proposes a digital average current mode control method in discontinuous conduction mode (DCM) power factor correction (PFC) rectifier. The proposed control technique can directly sense the average value of the inductor current in each switching cycle digitally by employing a conventional current sensing circuit. Thanks to the current control loop, high speed analog-to-digital converters (ADC's) or high performance digital IC's are not needed. The technique achieves lower total harmonic distortion (THD) and higher power factor (PF) than conventional DCM PFC rectifiers. Experimental results using prototype hardware verify the feasibility and performance of the proposed sensing method.

关键词： Inductors Rectifiers Sensors Switches Voltage control Current control

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