To bridge the gap between insufficiency of existing proximity authentication solutions and the increasing demand of high security guarantee for access control systems, we develope a WISP-based access control system co...
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Generally, localization is a nonlinear problem, while linearization is used to simplify this problem. Reasonable approximations could be achieved when signal-to-noise ratio (SNR) is large enough. Energy is a critical ...
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Generally, localization is a nonlinear problem, while linearization is used to simplify this problem. Reasonable approximations could be achieved when signal-to-noise ratio (SNR) is large enough. Energy is a critical resource in wireless sensor networks, and system lifetime needs to be prolonged through the use of energy efficient strategies during system operation. In this paper, a closed-form solution for received signal strength (RSS)-based source localization in wireless sensor network (WSN) is obtained. A sensor selection method is proposed to improve the localization accuracy as well as to save energy consumption. By selecting only a limited number of sensor nodes based on the model accuracy and geometry structure analysis, localization performance is improved, and energy consumption is reduced. In addition, extensive simulations are presented to demonstrate that the estimation performance with the proposed sensor selection method is better than that without sensor selection.
For the rotor speed control of the grid-connecting of wind turbines with hydraulic transmission, the system dynamics model is built. To address the difficulty in accurate control of rotor speed for external disturbanc...
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For the rotor speed control of the grid-connecting of wind turbines with hydraulic transmission, the system dynamics model is built. To address the difficulty in accurate control of rotor speed for external disturbance and uncertain internal disturbances while connecting to the grid, an adaptive Backstepping controller was designed. The convergence was proved with Lyapunov stability theory. The condition of a constant rotor speed for connecting to grid was meted. The simulation results show that the systerm provides a good dynamic response and strong robustness when system parameters and load torque disturbances appeared.
Crowd panic behavior detection is an important task in video analysis and event recognition, whose purpose is to detect when the panic behavior happened and alarming the abnormal event timely. In this paper, the crowd...
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Crowd panic behavior detection is an important task in video analysis and event recognition, whose purpose is to detect when the panic behavior happened and alarming the abnormal event timely. In this paper, the crowd is regard as a fluid, and the crowd motion is described by four fluid kinematic features (divergence, vorticity, gradient tensor invariant and rotation tensor invariant). To discriminate the panic event from normal crowd behavior, an information entropy is calculated as a high level feature based on the fluid kinematic features. Experimental results show that the entropy raised dramatically once a panic event happened.
Vision-based human action recognition provides an advanced interface, and research in this field of human action recognition has been actively carried out. This paper describes a scheme for recognizing human actions f...
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Vision-based human action recognition provides an advanced interface, and research in this field of human action recognition has been actively carried out. This paper describes a scheme for recognizing human actions from a video sequences. The proposed method is an extension of the Motion History Image(MHI) method based on the ordinal measure of accumulated motion, which is robust to variations of appearances. We define the accumulated motion image(AMI) using image differences firstly. Then the AMI of the video sequencesis resized to a M×N regulation following the standard of training phases. Finally, we employ Support Vector Machine(SVM) as a classifier to distinguish the current activity in target video sequences. In a word, our proposed algorithm not only outperforms the state of art on public available KTH data set and Weizmann data set, but also proves practical to some real world applications, in addition, this method is computationally simple and able to achieve a satisfactory accuracy.
This paper analyzes the performance of object tracking algorithms. The issues that affect precision in object tracking are analyzed first and how the parameters in tracking algorithms affect the precision in object tr...
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Through analyzing of the electric power steering (EPS) structure and union the vehicle dynamic characteristics, this paper establishes a mathematical model of EPS. And the EPS system simulation model based on Matlab/S...
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The information of target size is useful for a lot of target tracking applications of wireless sensor networks, however, it has been neglected in most existing work. This paper considers the problem of target tracking...
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In this paper, we design and implement a reliable data processing and analysis test bed (NESCTB) for wireless sensor networks (WSNs). It contains 36 wireless sensor nodes connected through Ethernet to a central server...
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