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11th International Conference on Electrical Machines and systems(第11届国际电机与系统会议)

作者： Yunhao Jiang Weiming Ma Zhihua Zhao College of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuh National Key Laboratory for Vessel Integrated Power System Technology Naval University of Engineeri

An adaptive sinusoidal interference cancellation system is analyzed in time-domain. Through the evaluation of the time-varying difference equation group, exact analytical solutions are gained. The necessary and sufficient condition for the convergence of the system and the step size μ which makes the system converge fastest are calculated. For LMS (least mean squares) algorithm, the two-step convergence can be realized. The analyses are in agreement with the computer simulation.

关键词： Interference cancellation Noise cancellation Signal processing algorithms Least squares approximation Signal design Power engineering and energy Time domain analysis Sufficient conditions Adaptive filters Adaptive systems

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Flight-by-wire control strategy: An implementation of stepping simulation approach

Flight-by-wire control strategy: An implementation of steppi...

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International Symposium on systems and Control in Aerospace and Astronautics (ISSCAA)

作者： F. Xu T. Wang Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing China

Flight control system is extremely important for the aircraft flight safety and quality. With the rapid and continual development in modern aeronautical fields, fly-by-wire control (FBW)system has become the leading of aircraft design and application. In this paper, aim at the need of the certain cargo-transport, the modeling and simulation as well as the parametric-optimization of flight control system are systematically discussed, based on MATLAB/Simulink. The mechanical model of the flight control system is presented, and a suit of flight control law is proposed. The model of flight control system is set forth in MATLAB/Simulink based on the control law, the real-time simulation of control system, the analysis of planepsilas dynamic response characteristics, and the modification and optimization of the system parameters are implemented. The FBW system is analyzed by stepping simulation, and the effects on the dynamic character of the whole systempsilas response due to each block is studied.

关键词： Aerospace simulation Aerospace control Mathematical model Aircraft MATLAB Analytical models Aerodynamics Air safety Aerospace safety Real time systems

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Analysis on the parameters of adhesively bonding patch repairing cracked sandwich face panel

Analysis on the parameters of adhesively bonding patch repai...

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International Conference on system Simulation and Scientific Computing, ICSC

作者： Yuequan Wang Mingbo Tong Shuhua Zhu Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing China

The parameters of adhesively bonding patch, which include patch materials, patch size, patch thickness, have been analyzed on the stress concentration factor and the stress intensity factor (SIF) thanks to the 3D finite element method (FEM) in the paper. The adhesive shear modulus and thickness are studied in this paper as well. The aluminum sandwich face panel is analyzed and the results show that the Boron/Epoxy composite patch reduces more stress concentration factor and SIF comparing with the other patches. The stress concentration factor reaches the minimum when the fiber orientates the tension direction. Meanwhile, the stress concentration in the patch and the adhesive reach the maximum. The stress concentration factor in the aluminum face sheet decreases with the increasing patch thickness. But the effect of the patch thickness weakens when the patch thickness is larger than the face panel. The impact of the adhesive thickness on the stress concentration of the face panel reduces with the increasing adhesive shear modulus. The stress concentration factor increases when the adhesive thickness increases. The results are useful to design the bonded composite patch repair.

关键词： Bonding Stress Aluminum Laboratories Space technology Vehicles Laminates Finite element methods Aircraft Resists

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design of an adaptive shock absorber of landing gear and preliminary analysis on taxiing performance

Design of an adaptive shock absorber of landing gear and pre...

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International Conference on system Simulation and Scientific Computing, ICSC

作者： Shuhua Zhu Mingbo Tong Jie Xu Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and Astronautics Nanjing China Structure department ChengDu Aircraft Design and Research Institute Chengdu China

A special adaptive shock strut of landing gear with double-cavity and double damping is studied in the paper. Its mathematical model and virtual prototype, which is established based on the software ADAMS, are described. The paper has emphatically studied the sensitivities of its different configurations and main parameters to the taxiing performance of landing gear. The analysis shows that all of the side orifice, variable orifice and the high pressure cavity can reduce the overload and stroke of the adaptive shock absorber. The results also show that adjusting the pressure of the double cavities can reduce more overload than adjusting these volumes. The results obtained in the paper have reference value for the landing gear design of the large aircraft.

关键词： Shock absorbers Gears Performance analysis Orifices Electric shock Damping Mathematical model Software prototyping Virtual prototyping Aircraft

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Modified min-sum decoding algorithm for LDPC codes based on classified correction

Modified min-sum decoding algorithm for LDPC codes based on ...

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International Conference on Communications and Networking in China (CHINACOM)

作者： Zhou Zhong Yunzhou Li Xiang Chen Hanying Hu Jing Wang State Key Laboratory on Microwave and Digital Communications National Laboratory for Information Science and Technology Department of Electronic Engineering Tsinghua University Beijing China National Digital Switching System Engineering and Technological Research and Development Center Zhengzhou China

In this paper, a modified min-sum decoding algorithm based on classified correction is proposed for low density parity check (LDPC) codes. Different from the single correction in the normalized belief propagation (BP)-based and offset BP-based algorithms [4], the proposed algorithm utilizes two corrections for both minimum and sub-minimum magnitudes of input messages in check nodes. These two correction factors can be obtained by analyzing the offset of updated messages in check nodes between the BP and the min-sum algorithms associated with check node degree. Simulation results show that the proposed algorithm can achieve performance very close to that of the BP algorithm. Furthermore, the FPGA implementation of this algorithm can reach a throughput of 200 Mbps at BER=10 -6 with lower complexity and fewer resources than the BP algorithm.

关键词： Parity check codes Iterative algorithms Approximation algorithms Iterative decoding AWGN Laboratories Microwave technology Belief propagation Algorithm design and analysis Field programmable gate arrays

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An Automatic and Scalable Testing Tool for Workflow systems

An Automatic and Scalable Testing Tool for Workflow Systems

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International Conference on Grid and Pervasive Computing Workshops, GPC

作者： Lin Quan Xiaozhu Lin Jianmin Wang Key Laboratory for Information System Security Ministry of Education China School of Software Tsinghua University Beijing China Computer and Information Management Center Tsinghua University China Tsinghua National Laboratory for Information Science and Technology China

Nowadays workflow systems are widely deployed around the world, especially within large international corporations. Thus the performance evaluation of these workflow systems becomes an important topic, especially in grid environment. We have developed an automatic and scalable testing tool to evaluate workflow systems. This tool is named Scalable Workflow system Evaluation Tool (SWEET). SWEET can automatically test against workflow systems according to a highly customizable process template specified by users. It can also provide multi-layer performance metrics related to response time, throughput and fairness. Further, it can adoptively determine the maximum concurrency of a workflow system under a desired average processing time, using control theory (PI Controller). In this paper, we will present the design and architecture of SWEET. We will also discuss the evaluation metrics and our implementation of such a framework. Finally, we will give detailed experimental results and analysis.

关键词： Automatic testing system testing Delay Concurrent computing Measurement Pervasive computing Software testing Software tools Laboratories Automatic control

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Data segments aggregation performance in next generation avionics systems

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Guangxue Xuebao/Acta Optica Sinica 2008年第SUPPL. 2期28卷 253-257页

作者： Huang, Hui He, Hao Jin, Yaohui Huang, Haoyi Wu, Jianmin State Key Laboratory on Advanced Communication Systems and Networks Shanghai Jiaotong University Shanghai 200240 China National Defense Science and Technology Key Laboratory for Avionics System Integration Technology Shanghai 200233 China

We integrate the advantages of optical packet switching (OPS) network and fibre channel (FC) technology, and put forward fibre channel transportation based on optical packet switching network (FC over OPS) as a solution for next generation avionics systems internetworking. We focus our research work on the interrelation between data segments aggregation and network real-timing performance. By simulation, we analyze the impact that bandwidth, minimum efficiency threshold and timing contribute to the network real-timing. Furthermore, we complete hardware prototype design and simulation, compare the results between software and hardware simulation and analyze the performance of this algorithm.

关键词： Packet switching

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Error bounded algorithm for approximate B-spline surface skinning

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Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided design and Computer Graphics 2008年第11期20卷 1477-1482页

作者： Wang, Wenke Zhang, Hui Wang, Bin School of Software Tsinghua University Beijing 100084 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China Key Laboratory for Information System Security Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Beijing 100084 China

B-spline surface skinning is a commonly used tool in surface modeling. Huge amounts of control points will be introduced in the skinned surface by traditional skinning approach. This paper proposes an efficient approximating skinning algorithm for constructing B-spline surface based on Piegl's approach. By a more precise estimation of maximum value of a B-spline basis function and utilizing of the local support property of B-spline basis function, the control points of a set of compatible B-spline curves are reduced, which makes the skinning algorithm more effective. Under the same error bound, experimental results showed that our algorithm can reduce more control points than Piegl's.

关键词： Interpolation

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Characterization and Crystal Structure of a New Holmium(III) Complex with the Macrocyclic Ligand Derived from 2,6-Diformyl-4-methylphenol and Diethylenetriamine

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Chinese Journal of Structural Chemistry 2007年第12期26卷 1429-1434页

作者：胡学雷邱立赵元弟key laboratory of Biomedical Photonics of Ministry of Education - Wuhan national laboratory for Optoelectronics - Hubei Bioinformatics and Molecular Imaging key laboratory - key laboratory of Molecular Biophysics of the Ministry of Education Huazhong University of science and technology 潘志权 Key Laboratory of Biomedical Photonics of Ministry of Education - Wuhan National Laboratory for Optoelectronics - Hubei Bioinformatics and Molecular Imaging Key Laboratory - Key Laboratory of Molecular Biophysics of the Ministry of Education Huazhong University of Science and Technology Hubei Key Laboratory of Novel Chemical Reactor and Green Chemical Technology Wuhan Institute of Technology

The title compound （13,27-dimethyl-3,6,9,17,20,23-hexaazatricyclo-[23.3.1.1^11.15]- triaconta-l（29）,2,9,11,13,15（30）,16,23,25,27-decaene-29,30-diol-N^3,N^6,N^9,O^29,O^30）-bis（nitrato-O,O＇）- holmium（m） nitrate hydrate has been prepared and characterized by elemental analysis, infrared spectra, and electrospray mass spectra. Its crystal and molecular structures were determined by X-ray diffraction methods. The crystal crystallizes in the monoclinic system, space group C2/c with a = 23.737（12）, b = 14.237（7）, c = 19.801（10） A, β = 91.36（1）^o, Mr = 831.57, V = 6690（6） A^3, Z = 8, Dc = 1.651 g/cm^3, F（000） = 3344, R = 0.0482 and wR = 0.0923. The holmium ion is located in one of the compartments of the macrocyclic ligand and presents a distorted tricapped trigonal prismatic coordination geometry. The macrocycle is coordinated with two oxygen and three nitrogen atoms. Two nitrates are chelated in the opposite positions of the macrocycle, and the third one is ionic.

关键词： crystal structure lanthanide macrocycle

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A novel method of modeling the electromagnetic spectrum management system for the fleet

A novel method of modeling the electromagnetic spectrum mana...

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2007 IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications, MAPE 2007

作者： Yu, Jing Liao, Rongtao Wen, Dinge National Key Laboratory of EMC China Ship Development and Design Center Wuhan 430064 China School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)1424410444

A dynamic distributed ship electromagnetic spectrum management system model based on multi-agent system (MAS) was presented in this article. The proposed system model was comprised of five kinds of agent: Data-Collector agent, Device-Operator agent, Analyze -Expert agent, Decision-Maker agent and Require/Command agent. Through the cooperation of agents, the system could solve spectrum apportionment for the formation of ships automatically. A we 11-organized central-plan with hierarchical management architecture was implemented by grading the agents into flagship and the other ships' decision-maker agents groups. It satisfies the distributed and dynamic requirement of ship formation in combined operation. © 2007 IEEE.

关键词： Ships

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