Information entropy based criteria are analyzed and the Normalized Mutual Information(NMI) that is presented in the field of image registration is revised to Normalized Mutual Information Entropy (NMIE) to meet the ne...
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This paper analyses the cause of the major faults of the SF6 high voltage circuit breaker, and then introduces a solution using an embedded control system. The control system consists of the controller for every break...
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This paper analyses the cause of the major faults of the SF6 high voltage circuit breaker, and then introduces a solution using an embedded control system. The control system consists of the controller for every breaker and a supervisor control system in the control center. Then a double-annular fiber field-bus communication network for the control system is introduced, of which the data link layer is implemented by the CAN controller. According to the operation state of every node and the fiber, the fiber communication module of every node can be configured to several different transmission modes. Due to the influence of temperature, the empirical formula of Beattie-Bridgman is used to calculate the pressure of SF6.
Web services are becoming the most promising technology for cloud computing. When a single web service fails to satisfy service requestor's multiple function demands, web services need to be configured together to...
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The content based image retrieval (CBIR) is aimed to find the most similar images from a collection of images or a database to the query image according to the visual or semantic similarity. Current image retrieval al...
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Modern power system is a typical multi-level complex giant system consisting of physical infrastructures, human operators, and social resources, etc. The conventional analytical methods and simulation systems can'...
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This paper considers the distributed quadratic stabilization problems of uncertain continuous-time linear multiagent systems with undirected communication topologies. It is assumed that the agents have identical nomin...
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This paper considers the distributed quadratic stabilization problems of uncertain continuous-time linear multiagent systems with undirected communication topologies. It is assumed that the agents have identical nominal dynamics while subject to different norm-bounded parameter uncertainties, leading to weakly heterogeneous multi-agent systems. A distributed controller is proposed, based on the relative states of neighboring agents and a subset of absolute states of the agents. It is shown that the distributed quadratic stabilization problem under such a controller is equivalent to the H∞ control problems of a set of decoupled linear systems having the same dimensions as a single agent. A two-step algorithm is presented to construct the distributed robust controller, which does not involve any conservatism and meanwhile decouples the feedback gain design from the communication topology. Furthermore, the distributed quadratic H∞ control problem of uncertain linear multi-agent systems with external disturbances is discussed, which can be reduced to the scaled H∞ control problems of a set of independent systems whose dimensions are equal to that of a single agent.
This paper aims to address the robust control problem of rigid spacecraft attitude maneuvers in the presence of inertia matrix uncertainty and external disturbance. A back-stepping based adaptive sliding mode control ...
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ISBN:
(纸本)9781467315593
This paper aims to address the robust control problem of rigid spacecraft attitude maneuvers in the presence of inertia matrix uncertainty and external disturbance. A back-stepping based adaptive sliding mode control (B-ASMC) design is proposed as a solution, where the upper bounds of the parametric uncertainty and disturbance are not required in advance. Compared to current adaptive sliding mode control (ASMC) design, the B-ASMC design has two advantages. Theoretically, the asymptotical stability of the attitude states rather than the sliding function is guaranteed. Practically, the over-adaptation problem in current ASMC design is alleviated and the system performance is improved. Detailed design principle and rigorous closed-loop system stability analysis are provided. A large angle attitude maneuver is employed in the numerical simulation to verify the effectiveness of the proposed algorithm.
This paper aims to present an improved adaptive sliding mode control (ASMC) design for rigid spacecraft attitude maneuvers. An adaptive scheme is proposed for the switching gain calculation when the upper bound of the...
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This paper aims to present an improved adaptive sliding mode control (ASMC) design for rigid spacecraft attitude maneuvers. An adaptive scheme is proposed for the switching gain calculation when the upper bound of the system uncertainty is unknown in advance. Unlike existing ASMC design, which may result in an over-adaptation of the upper bound when the initial system trajectory is located far from the sliding surface, this paper presents a novel ASMC strategy by introducing a decay term in the sliding function to reduce or eliminate the unrelated factor in the adaptation scheme. Consequently, a lower-chattering control signal is achieved. Simulation results are presented to illustrate the effectiveness of the proposed strategy.
Detecting text in video or natural scene image is quite challenging due to the complex background, various fonts and illumination conditions. The preprocessing period, which suppresses the nontext areas so as to highl...
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Detecting text in video or natural scene image is quite challenging due to the complex background, various fonts and illumination conditions. The preprocessing period, which suppresses the nontext areas so as to highlight the text areas, is the basis for further text detection. In this paper, a novel graph-based background suppression method for scene text detection is proposed. Considering each pixel as a node in the graph, our approach incorporates pixel-level and context-level features into a graph. Various factors contribute to the unary and pair wise cost function which is optimized via max-flow/min-cut algorithm [16] to get a binary image whose nontext pixels are suppressed so that text pixels are highlighted. Furthermore, the proposed background suppression method could be easily combined with other detection methods to improve the performance. Experimental results on ICDAR 2011 competition dataset show promising performance.
In this paper, we proposed an architecture of a hierarchical networked urban traffic signal control system Based on Multi-agent. With mobile agent technology, traffic control strategies are designed as traffic control...
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In this paper, we proposed an architecture of a hierarchical networked urban traffic signal control system Based on Multi-agent. With mobile agent technology, traffic control strategies are designed as traffic control agents, which can move from device to device in a network. The system can reconfigure and replace these agents according to inconstant states of traffic environment and performances of agents. By this way, demand-based control is realized in traffic signal control system. Then we described the details and key technologies in the procession of agent-generation, agent-storage and agent-usage. At last, a prototype of the system is developed and basic functions of this system are tested by simulations. These simulations also confirm extensibility and effectiveness of the system.
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