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International Conference on Computer engineering and systems

作者： Ghada Hamissa Amany Sarhan Hatem Abdelkader Mahmoud Fahmy Electrical Engineering Dept. Faculty of Engineering KFS University Kafr-Elsheikh Egypt Information System Department Faculty ofComputer & Information Menoufia University Menoufia Egypt Computer & Automatic Control Department Faculty of Engineering Tanta University Tanta Egypt

In the last two decades, Chaos theory has received a great deal of attention from the cryptographic community. This paper presents two ideas. First idea is using chaotic functions to overcome the weaknesses of the classical Hill cipher. The second idea is proposing a new encoder-decoder architecture, called ChaoEncoDeco, for securing JPEG images. An extra stage of encryption is embedded within the traditional JPEG codec to improve security level of such system. This security stage uses one of the chaotic functions called Logistic Map. This map is used to enhance the Hill cipher and achieve more secure encryption key. The properties of both chaotic system and of the Hill cipher encryption key are all utilized to obtain ultimate secure systems. The proposed encryption algorithm is crypto-analyzed and compared to the standard Hill cipher algorithm. Complete evaluation for the proposed architecture is also performed which indicates the effectiveness of the proposed system.

关键词： Cryptography Image coding Chaos PSNR Transform coding Time measurement Size measurement

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Static/dynamic tests of high-hardness rubber for response control and its time history analysis method

Journal of Structural and Construction Engineering

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Journal of Structural and Construction engineering 2011年第662期76卷 785-794页

作者： Kasaj, Kazuhiko Nishizawa, Keiji Ooki, Yoji Tanaka, Yoshimichi Tanaka, Kazuhiro Nishimoto, Kohji Yamazaki, Hisao Struct. Eng. Res. Center Tokyo Institute of Technology Japan Dept. of Built Environment Tokyo Institute of Technology Japan Center for Urban Earthquake Eng. Tokyo Institute of Technology Japan Hybrid Rubber Products Headquarters Sumitomo Rubber Industries Ltd. Japan Building Construction and Steel Structures Div. Nippon Steel Engineering Japan Dynamic Analysis Research Complex Union System Inc. Japan

This paper proposes a time-history analysis model of high-hardness rubber that was recently developed for seismic vibration control of structures. The model combines elasto-plastic, visco-elastic, and nonlinear viscous constitutive rules. The rubber mechanical properties depend on frequency, temperature, and strain amplitude. The dependencies are effectively modeled through findings of their equivalencies. The nonlinearities under the idealized harmonic loading as well as random loading are carefully considered in the model. The model shows excellent accuracy over a wide range of temperature, frequency, and shear strains of a variety of histories.

关键词： Rubber

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Robust sliding mode control for a wind turbine system

Robust sliding mode control for a wind turbine system

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作者： Barambones, Oscar Dept. of Automatic Control and System Engineering University of the Basque Country University College of Engineering of Vitoria Nieves cano 12 Vitoria Spain

ISBN: (纸本)9783902661685

The actual wind turbines are provided with adjustable speed generators, like the double feed induction generator, that are capable to work in variable speed operations. One of the main advantage of adjustable speed generators is that they improve the system efficiency compared to fixed speed generators because turbine speed is adjusted as a function of wind speed to maximize output power. However this systems requires a suitable speed controller in order to track the optimal wind turbine speed reference. In this work, it is proposed a sliding mode control for variable speed wind turbines. The robustness analysis of the proposed controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory and simulated results show that the proposed controller provides a good performance.

关键词： Robust control

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A PI-based control scheme for primary cascaded H-bridge rectifier in transformerless traction converters

A PI-based control scheme for primary cascaded H-bridge rect...

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作者： Xinghua, Tao Yongdong, Li Min, Sun State Key Lab of Control and Simulation of Power System and Generation Equipments Dept. of Electrical Engineering Tsinghua University China Dept. of Electrical Engineering Naval Engineering University China

ISBN: (纸本)9788986510119

Cascaded H-Bridge rectifier (CHBR) is a more attractive solution in traction application for its transformerless structure. Because of the currents of different cells are exactly the same one, it is a challenge job to regulate the voltages of cells with only one current controller. In this paper, a PI-based control scheme is presented to deal with the voltages balance issue in CHBR. To satisfy the demand of rectifier such as unity power factor and regulated output DC voltages, the proposed control scheme consists of two parts. One is for shaping the grid current waveform and regulating the sum of DC-link voltages of all the cells;the other one is for balancing DC-link voltages. The latter is more concerned in this paper and is discussed in detail especially. Simulations and experiments are carried on. The results verified the feasibility and effectiveness of the proposed scheme.

关键词： Electric rectifiers

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A phase-disposition PWM method for DC voltage balance in cascaded h-bridge rectifier

A phase-disposition PWM method for DC voltage balance in cas...

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作者： Tao, Xinghua Li, Yongdong Sun, Min State Key Lab of Control and Simulation of Power System and Generation Equipments Dept. of Electrical Engineering Tsinghua University China Dept. of Electrical Engineering Naval Engineering University China

ISBN: (纸本)9788986510119

In this paper, a novel control scheme for cascaded H-Bridge rectifier (CHBR), which can be used as the primary end of high voltage high power multilevel converters, is presented. The controller is similar with the one for single phase rectifier. To improve the performance of the controller, notch filter and proportion resonance (PR) controller are employed and the discrete methods for them are discussed in detail. The different function of CHBR controller from the single rectifier is for voltage balancing. Therefore, the phase-disposition technology, which is used in the multilevel converter, is introduced to eliminate the voltage error from the expected value. With this approach, the states of the switches of the CHBR are decided correctly by the practical condition and then the DC-link capacitors of the cells are controlled to charge or discharge in the way which results to voltage balancing. The effectiveness of the proposed approach is verified by experimental results.

关键词： controllers

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Application of back propagation neural network to fault diagnosis of direct-drive wind turbine

Application of back propagation neural network to fault diag...

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2010 2nd World Non-Grid-Connected Wind Power and Energy Conference, WNWEC 2010

作者： An, Xueli Jiang, Dongxiang Li, Shaohua State Key Laboratory of Control and Simulation of Power System and Generation Equipments Dept. of Thermal Engineering Tsinghua University Beijing 100084 China

ISBN: (纸本)9781424489213

The vibration signals of wind turbines are highly nonlinear and non-stationary due to wind turbine operation conditions that are very complicated. The signals will be more complex when a fault occurs. Aiming at these problems, a fault diagnosis method for direct-drive wind turbine is presented based on back propagation neural network (BPNN). The time-domain feature parameters of vibration signals in the horizontal and vertical direction are considered in the method. Five experiments of direct-drive wind turbine with normal, wind wheel mass imbalance, wind wheel aerodynamic imbalance, yaw and blade break are carried out in laboratory scale. Through analyzing the features of five conditions, the time-domain feature parameters in horizontal and vertical direction of the vibration signal are selected as the input samples of BPNN. By training, the BPNN model can be constructed between feature parameters and fault types. The validity of the BPNN model is verified using test samples. The results indicate that the proposed method has higher diagnostic accuracy. It can used in on-line fault diagnosis of direct-drive wind turbines. © 2010 IEEE.

关键词： Failure analysis

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A phase-disposition PWM method for DC voltage balance in cascaded h-bridge rectifier

A phase-disposition PWM method for DC voltage balance in cas...

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2010 International Conference on Electrical Machines and systems, ICEMS2010

关键词： Cascaded H-bridge rectifier Phase-disposition PWM PR controller Voltage balance

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Multi objective optimization for piloting a Quality Management system: Study case

Multi objective optimization for piloting a Quality Manageme...

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2010 International Conference on system Science and engineering, ICSSE 2010

作者： Mahmoud, H. Ben Ketata, R. Romdhane, T. Ben Ahmed, S. Ben Dept. of Physics and Instrwnentation Engineering INSAT: National Institute of Applied Science and Technology Tunis Tunisia Dept. of Physics and Instrwnentation Engineering ICOS: Research Unit on Intelligent Control Design and Optimization of Complex System Tunis Tunisia Dept. of Physics and Instrumentation Engineering MOSIC Research Unit on Methods and Tools for Complex Computer Systems Tunis Tunisia

ISBN: (纸本)9781424464746

This paper presents a decision support tool for the effectiveness of a Quality Management system (QMS) in a company. To develop this tool, a new approach PAHP based on the combination of the Pareto Optimality Concept (Poq and the Analytical Hierarchy Process (AHP). This approach is used to model and optimize the multi-objective function of real company which presents a major problem for controlling the quality level of production. © 2010 IEEE.

关键词： Multiobjective optimization

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A study of vehicle energy analysis during warming up process using VHDL-AMS multidomain simulation

A study of vehicle energy analysis during warming up process...

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2010 International Power Electronics Conference - ECCE Asia -, IPEC 2010

作者： Tsuji, Kimitoshi Kido, Yasunari Abe, Takashi Advanced Vehicle Control System Engineering Dev. Toyota Motor Corporation 1200 Mishuku Susono Shizuoka 410-1193 Japan Vehicle Control System Engineering Dev. Toyota Motor Corporation 1 Toyota-cho Toyota Aichi 471-8572 Japan Dept. of Electrical and Electronic Engineering Nagasaki University 1-14 Bunkyou-machi Nagasaki 852-8521 Japan

ISBN: (纸本)9781424453955

In this paper, by employing thermal characteristic modeling to the main components of the vehicle model for example, engine, transmission and battery, we examine the heat energy management and fuel consumption of the testing drive patterns especially during warming up process. The simulation data agree well with measurement data. Our vehicle simulation results provide VHDL-AMS validity for multi-domain energy management and the vehicle system planning. © 2010 IEEE.

关键词： Energy management

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Improving motion of robotic manipulators by an embedded optimizer

Improving motion of robotic manipulators by an embedded opti...

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2010 IEEE International Conference on Automation Science and engineering, CASE 2010

作者： Ding, Hao Schnattinger, Georg Passenberg, Benjamin Stursberg, Olaf Institute of Control and System Theory Dept. of Electrical Eng. and Computer Science University of Kassel Germany Institute for High-Frequency Engineering Technische Universität München 80290 München Germany Institute of Automatic Control Engineering Technische Universität München 80290 München Germany

ISBN: (纸本)9781424454471

A control scheme for efficient and safe path and motion planning of industrial robots is proposed. For motion planning of robotic manipulators, an offline method is developed which generates feasible trajectories of the joints such that a given performance criterion is maximized. The planning problem considering obstacle avoidance is converted to an optimization problem with interior points for the joint angles to guide the trajectory away from obstacles. The interior points are generated from an approach of rapidly exploring random trees (RRTs] in the configuration and time space. The method is applied to a 3-DOF-robot with known dynamic moving obstacles and evaluated afterwards. Online motion generation of industrial robots is then discussed for a human robot interaction scenario. ©2010 IEEE.

关键词： Motion planning

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