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Optimization of thermomechanical processes in Cu-Cr-Zr lead frame alloy using neural networks and genetic algorithms

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Science China(Technological Sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1,2. LIU Ping2. DONG Qiming2.& LI Hejun1 1. College of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072. China 2. College of Materials Science and Engineering, Henan University of Science and technology, Luoyang 471003, China 1. College of Materials Science and Engineering Northwestern Polytechnical University 710072 Xi’an China 2. College of Materials Science and Engineering Henan University of Science and Technology 471003 Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

The structural analysis of fuzzy measures

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Science China(Information Sciences) 2011年第1期54卷 38-50页

作者： ZHANG Ling1,ZHANG Bo2.& ZHANG YanPing1 1 Computer Science College,Anhui University,Hefei 2.0039,China 2.0} Key Lab of intelligent {2. & systems Tsinghua National Lab for Information Science & {2. Information Science & {2. College,Computer Science & {2.,Tsinghua University,Beijing 100084,China 1. Computer Science College Anhui University Hefei 230039 China2. State Key Lab of Intelligent Technology & Systems Tsinghua National Lab for Information Science & technology Information Science & technology College Computer Science & Technology Tsinghua University Beijing 100084 China

From quotient space based granular computing theory we explore the fuzzy measures of fuzzy sets. Based on the structural analysis of fuzzy sets,we present an"isotropism"*** this assumption we achieved the following insights:(1)the uniqueness of a fuzzy measure being isotropic on a finite complete semi-ordered set;(2.the necessary and suffcient condition of the isomorphism for fuzzy measure functions in fuzzy mathematics;(3)the necessary and suffcient condition that fuzzy measures have fuzzy and granular monotonicity;(4)under a certain assumption,the analytic expression for fuzzy *** results clarify the relationship between fuzzy measures and granular computing,reveal the essence of fuzzy measures,and provide a simple way of constructing fuzzy measures.

关键词： quotient space fuzzy set fuzzy measure rough set structural analysis

On the placement of actuators and sensors for flexible structures with closely spaced modes

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Science China(Technological Sciences) 2010年第7期53卷 1973-1982页

作者： LIU XiaoXiang1,2.& HU Jun1,2.1 Beijing Institute of Control Engineering, Beijing 100190, China 2.state Key Laboratory of Science and technology on Space {2. Control, Beijing 100190, China 1. Beijing Institute of Control Engineering Beijing 100190 China2. State Key Laboratory of Science and Technology on Space Intelligent Control Beijing 100190 China

This paper analyzed the fundamental limitations of previous work and developed a new method to optimally locate actuators and sensors for structures with close modes. Optimization criteria were defined based on the distinguishing modal controllability and observability measures of close modes. An appropriate genetic algorism was adopted as the optimization algorism. Solving the high order Lyapunov functions was avoided by means of the closed-form expressions for controllability and observability Grammians. Since structure with widely separated natural frequencies is approximately balanced, computational efficiency was improved by grouping close modes together and dealing with the resulting subsystems independently. Finally, the effectiveness and optimality of the novel placement scheme were verified on a model structure with close modes.

关键词： close modes controllability/observability sensor/actuator optimization criterion optimization algorithm

Fusion tracking in color and infrared images using joint sparse representation

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Science China(Information Sciences) 2012年第3期55卷 590-599页

作者： LIU HuaPing1,2.3 & SUN FuChun1,2.3 1Department of Computer Science and technology, Tsinghua University, Beijing 100084, China 2.1} Key Laboratory of {2. technology and systems, Beijing 100084, China 3Tsinghua National Laboratory for Information Science and technology, Beijing 100084, China 1. Department of Computer Science and technology Tsinghua University Beijing 100084 China2. State Key Laboratory of Intelligent Technology and Systems Beijing 100084 China3. Tsinghua National Laboratory for Information Science and Technology Beijing 100084 China

Currently sparse signal reconstruction gains considerable interest and is applied in many fields. In this paper, a similarity induced by joint sparse representation is designed to construct the likelihood function of particle filter tracker so that the color visual spectrum and thermal spectrum images can be fused for object tracking. The proposed fusion scheme performs joint sparse representation calculation on both modalities and the resultant tracking results are fused using min operation on the sparse representation coefficients. In addition, a co-learning approach is proposed to update the reference templates of both modality and enhance the tracking robustness. The proposed fusion scheme outperforms state-of-the-art approaches, and its effectiveness is verified using OTCBVS database.

关键词： joint sparse representation fusion tracking color image infrared image

Fuzzy tracking control design for hypersonic vehicles via T-S model

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Science China(Information Sciences) 2011年第3期54卷 521-528页

作者： GAO DaoXiang 1 & SUN ZengQi 2.1 School of technology, Beijing Forestry University, Beijing 100083, China 2.state Key Laboratory of {2. technology and System, Department of Computer Science and technology, Tsinghua University, Beijing 100084, China 1. School of technology Beijing Forestry University Beijing 100083 China2. State Key Laboratory of Intelligent Technology and System Department of Computer Science and Technology Tsinghua University Beijing 100084 China

The main focus of this paper is on designing a T-S fuzzy controller for the hypersonic vehicle. The longitudinal dynamics of the vehicle are studied using time-scale decomposition to reduce the complexity of T-S modeling. The dynamic inversion with PI control technique is applied for the slow dynamics to derive the flight path angle command and throttle setting by taking the pilot altitude and velocity command as its inputs. The T-S fuzzy controller is designed for the fast dynamics to derive the elevator deflection to track the flight path angle command. The discrepancy between the T-S model and real vehicle model is considered by using sliding mode control for the system stability. Simulation results are included to show the effectiveness of the controller.

关键词： fuzzy control T-S model sliding mode control hypersonic vehicle

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Science China Earth Sciences 2004年第10期47卷 896-911页

作者： ZHANG Changhou1,2. WU Ganguo1,2. WANG Genhou2. ZHANG Weijie2.& SONG Honglin2.1. Key Laboratory of Lithospheric Tectonics and Lithoprobing technology, China University of Geosciences, Ministry of Education of China, Beijing 100083, China 2. School of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083, China 1. Key Laboratory of Lithospheric Tectonics and Lithoprobing technology China University of Geosciences Ministry of Education of China 100083 Beijing China 2. School of Earth Sciences and Mineral Resources China University of Geosciences 100083 Beijing China

The northwest trending tectonic belt in the middle part of the Mesozoic intraplate Yanshan Orogenic Belt, northeast Hebei Province, is composed of thrusts, extensional faults, strike-slip faults and syntectonic sedimentations as well. The northeastward basement-involved major thrusting deformation occurred between 174Ma and 168MaBP and was followed by an intrusion of the granitic plutonic rocks. As a part of the post-thrusting extensional deformations a northwest extending volcano-sedimentation system of Late Jurassic and Early Cretaceous formed in the southwest side of the belt. These volcano-sedimentary sequences are divided into Tuchengzi Formation, Zhangjiakou Formation, Yixian Formation and Jiufotang Formation re- spectively. They are characterized by southeastward migration as a result of the increasing down-dip slip displacement along the major extensional fault toward the southeast of the belt. The provenance area of the Jiufotang Formation north to it experienced southwestward thrusting during and after its later sedimentation. The thrusting in this stage resulted in the formation of an asymmetric footwall syncline with vergence to SW in the Jiufotang Formation in the NE side of the basin. Finally a dextral strike-slip deformation occurred along the NW tectonic belt. The striking tectono-geomorphological features and present seismic activities along this belt indicate that it has been being active since Cenozoic era and is still in the active state at present. This northwest extending tectonic belt was following the same direction and location as the existing fault systems within the basement as revealed by former geological and geophysical studies. So it is reasonable to infer the Mesozoic deformation along this belt to be a result of reactivation of the basement structures in a favorable tectonic stress field. The reactivation of basement struc- tures might be taken as one of the mechanisms of intraplate deformation and orogeny.

关键词： Yanshan Orogenic Belt, northwest extending tectonic complex, thrust system, geochronology.

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural Science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2. FENG Zhijing1 and CHENG Kai3(1. state Key Laboratory of Tribiology, Tsinghua University, Beijing 100084, China 2. Department of Material Sciences, Changchun University of Science and technology, Changchun 13002., China 3. Faculty of Information and Engineering {2., City Campus, Leeds LS1 3HE, UK) state Key Laboratory of Tribiology Tsinghua University Beijing 100084 China Department of Material Sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and Engineering systems City Campus Leeds LS1 3HE UK

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.2. nm root mean square (RMS) after 2. min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.

The Optimum Model and Its Decision Support System of Coal Quality Balance

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systems Science and systems Engineering 2000年第1期10卷 87-92页

作者： MENG Xiang\|rui\+1,\ SHU Hang\+2.1. Huainan Institute of technology, Huainan 2.2.01, China 2. state Plan Council, Beijing 10082., China

The meaningfulness and significance of coal quality balance have been summarized in this paper and practical steps concerning constructing the synthetic tech\|economic model and its decision support system of coal quality balance using the optimization technique of inverse recurrence of established initializing parameters have also been introduced. The principles and methods as applied in the model system development and procedure construction have been discussed accordingly.

关键词： coal quality balance tech\|economic model decision support system

Optimal MAC based cooperative spectrum sensing in cognitive radio networks

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Science China(Information Sciences) 2012年第6期55卷 1388-1396页

作者： CHEN Zhong 1,ZHANG XianDa 1 & YANG LanJuan 2.1 state Key Laboratory of intelligent {2. and systems,Tsinghua National Laboratory for Information Science and {2.,Department of Automation,Tsinghua University,Beijing 100084,China 2.Institute of Command Automation,PLA University of Science and {2.,Nanjing 2.0007,China 1. state Key Laboratory of intelligent {2. and systems Tsinghua National Laboratory for Information Science and Technology Department of Automation Tsinghua University Beijing 100084 China2. Institute of Command Automation PLA University of Science and Technology Nanjing 210007 China

This paper considers a cognitive radio (CR) system in non-ideal fading wireless channels and pro-poses cooperative spectrum sensing schemes based on coherent multiple access channels (MAC),serving as an alternative way to improve the cooperative spectrum sensing performance and provide space diversity for spec-trum *** statistics are transmitted using a common channel from the secondary users (SUs) to a fusion center (FC) where the global decision is *** optimal scaling factors of the proposed schemes are obtained by maximizing the detection probability under a target false alarm probability and a transmit power *** the proposed optimal MAC scheme has high computational complexity,a sub-optimal solu-tion based on maximization of the deflection coefficient (DC) is also *** results show that the proposed algorithms can significantly improve the spectrum sensing performance and approach the detection baseline.

关键词： cognitive radio (CR) spectrum sensing multiple access channel (MAC) deflection coefficient optimization