检索结果-南通市图书馆

Fuzzy tolerance quotient spaces and fuzzy subsets

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2010年第4期53卷 704-714页

作者： ZHANG Ling1 & ZHANG Bo2,3.4* 1Computer Science & technology College, Anhui University, Anhui 23.03., China 2state key laboratory of intelligent technology and systems, beijing 100084, China 3.singhua National{3. of Information Science & technology, beijing 100084, China 4Information Science & technology College, Computer Science & technology Department, Tsinghua University, beijing 100084, China 1. Computer Science & technology College Anhui University Anhui 230039 China2. State Key Laboratory of Intelligent Technology and Systems Beijing 100084 China3. Tsinghua National Laboratory of Information Science & Technology Beijing 100084 China4. Information Science & Technology College Computer Science & Technology Department Tsinghua University Beijing 100084 China

The structure and characteristic of fuzzy subsets are discussed by using the concepts of granulation and hierarchy in quotient space theory. First, the equivalence relation based quotient space theory is extended to the fuzzy tolerance relation. Second, the isomorphism and its discriminant of fuzzy tolerance relations are discussed. Finally, by using the fuzzy tolerance relation to define the fuzzy subset, its properties are addressed. The main results are given below: (1) several equivalent statements of fuzzy tolerance relations; (2) the definition of isomorphism of fuzzy tolerance relations; (3. the isomorphic discriminant of fuzzy tolerance relations; (4) the definition and properties of fuzzy subsets based on the fuzzy tolerance relations; and (5) the necessary and sufficient condition of the isomorphism of fuzzy subsets. These results will help us further comprehend the concepts of fuzzy tolerance relations and fuzzy subsets.

关键词： Fuzzy tolerance relation quotient space isomorphism fuzzy subset

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

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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{3. key laboratory of intelligent 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

Simulation study of phase retrieval for hard X-ray in-line phase contrast imaging

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2005年第4期48卷 450-458页

作者： YU Bin1,2, PENG Xiang1,2, TIAN Jindong1, NIU Hanben1, DIAO Luhong3.& LI Hua3.1. key laboratory of Optoelectronic Devices and systems of Ministry of Education, Institute of Optoelec- tronics, Shenzhen University, Shenzhen 518060, China 2. {3. key laboratory of Precision Measuring technology and Instruments, Tianjin University, Tianjin 3.0072,China 3. key laboratory of intelligent Information Processing, Institute of Computing technology, Chinese Academy of Sciences, beijing 100080,China 1. key laboratory of Optoelectronic Devices and systems of Ministry of Education Institute of Optoelectronics Shenzhen University 518060 Shenzhen China 2. state key laboratory of Precision Measuring {3. and Instruments Tianjin University 300072 Tianjin China 3. key laboratory of intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences 100080 Beijing China

Two algorithms for the phase retrieval of hard X-ray in-line phase contrast imaging are presented. One is referred to as Iterative Angular Spectrum Algorithm (IASA) and the other is a hybrid algorithm that combines IASA with TIE (transport of intensity equation). The calculations of the algorithms are based on free space propagation of the angular spectrum. The new approaches are demonstrated with numerical simulations. Comparisons with other phase retrieval algorithms are also performed. It is shown that the phase retrieval method combining the IASA and TIE is a promising technique for the application of hard X-ray phase contrast imaging.

关键词： X-ray optics, phase contrast imaging, phase retrieval, angular spectrum, hard X-ray.

The structural analysis of fuzzy measures

在线全文

学校读者我要写书评

暂无评论

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 23.03.,China 2state key Lab of intelligent {3. & {3. Tsinghua National Lab for Information Science & {3. Information Science & {3. College,Computer Science & {3.,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

Quantum threshold group signature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2,3.& WEN QiaoYan4 1 College of Computer Science and technology, beijing University of technology, beijing 100124, China 2 state key laboratory of Integrated Services Network, Xidian University, Xi’an 710071, China 3.state key laboratory of Information Security (Graduate University of Chinese Academy of Sciences), beijing 100049, China 4 state key laboratory of Networking and Switching technology, beijing University of Posts and Tele-communications, beijing 100876, China College of Computer Science and technology Beijing University of Technology Beijing 100124 China state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China state key laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China state key laboratory of Networking and Switching {3. Beijing University of Posts and Telecommunications Beijing 100876 China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography

Threshold quantum secret sharing between multi-party and multi-party

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2008年第9期51卷 1308-1315页

作者： YANG YuGuang1,2,3.& WEN QiaoYan4 1 College of Computer Science and technology,beijing University of technology,beijing 100124,China 2 state key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,China 3.state key laboratory of Information Security (Graduate University of Chinese Academy of Sciences),beijing 100049,China 4 state key laboratory of Networking and Switching technology,beijing University of Posts and Tele-communications,beijing 100876,China College of Computer Science and technology Beijing University of Technology Beijing 100124 China state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China state key laboratory of Information Security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China state key laboratory of Networking and Switching {3. Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single photons,which is useful and efficient when the parties of communication are not all present. We described the process of this TQSS scheme and discussed its security. It was shown that entan-glement is not necessary for quantum secret sharing. Moreover,the theoretic effi-ciency was improved to approach 100% as almost all the instances can be used for generating the private key,and each photon can carry one bit of information. This protocol is feasible with the present-day technique.

关键词： threshold quantum secret sharing quantum cryptography single photon multi-party and multi-party

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

在线全文

学校读者我要写书评

暂无评论

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 {3. {3. of Science and technology on Space intelligent 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

Threshold proxy quantum signature scheme with threshold shared verification

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2008年第8期51卷 1079-1088页

作者： YANG YuGuang1,3.4 & WEN QiaoYan2 1 College of Computer Science and technology,beijing University of technology,beijing 100124,China 2 state key laboratory of Networking and Switching technology,beijing University of Posts and Tele-communications,beijing 100876,China 3.state key laboratory of Integrated Services Network,Xidian University,Xi’an 710071,China 4 state key laboratory of Information Security(Graduate University of Chinese Academy of Sciences) ,beijing 100049,China 1. College of Computer Science and technology Beijing University of Technology Beijing 100124 China 3. state key laboratory of Integrated Services Network Xidian University Xi’an 710071 China 4. state key laboratory of Information Security (Graduate University of Chinese Academy of Sciences) Beijing 100049 China 2. state key laboratory of Networking and Switching {3. Beijing University of Posts and Telecommunications Beijing 100876 China

A threshold proxy quantum signature scheme with threshold shared verification is proposed. An original signer could authorize a group as its proxy signers. Then only t or more of n persons in the proxy group can generate the proxy signature on behalf of the original signer and any t-1 or fewer ones cannot do that. When the proxy signature needs to be verified,any t or more of n persons belonging to the verification group can verify the message and any t-1 or fewer ones cannot verify the validity of the proxy signature.

关键词： quantum signature threshold proxy quantum group signature threshold shared verification

Data acquisition and simulation of natural phenomena

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2011年第4期54卷 683-716页

作者： ZHAO QinPing state key laboratory of Virtual Reality {3. and {3.,Beihang University,beijing 100191,China 1. state key laboratory of Virtual Reality {3. and {3. Beihang University Beijing 100191 China

Virtual natural phenomena obtained through mathematical-physical modeling and simulation as well as graphics emulation can meet the user’s requirements for sensory experiences to a certain extent but they can hardly have the same accurate physical consistency as real natural *** technology for data acquisition and natural phenomena simulation can enable us to obtain multi-dimensional and multi-modal data directly from real natural phenomena and,based on these real data,to establish digital models highly consistent with real natural phenomena in appearance,physics,behavior or many other aspects,thus making a virtual natural phenomenon a direct mapping of real natural *** approach is conducive to resolving problems concerning the reliability and availability of virtual *** present the technology for acquiring and simulating dada of natural phenomena is still in its initial *** paper gives a review of the related ***,we briefly introduce the basic methods and techniques concerned,then,based on the difference between the basic elements of various natural phenomena,we discuss the current studies on such natural phenomena as light,water,fire,smoke,dynamic terrain,etc.,and finally,in connection with issues in the present research and possible future direction of development,we put forth a number of theoretical and technical problems,hoping they can be resolved in the near future.

关键词： natural phenomena data acquisition simulation data driven reliability