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RRM:An incentive reputation model for promoting good behaviors in distributed systems

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Science in china(Series F) 2008年第11期51卷 1871-1882页

作者： ZHANG Hong1,2,DUAN HaiXin1,3 & LIU Wu1,3 1 tsinghua National Laboratory for Information Science and Technology,tsinghua university,beijing 100084,china 2 department of Computer Science and Technology,tsinghua university,beijing 100084,china 3 Network Research Center,tsinghua university,beijing 100084,china tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China department of Computer Science and Technology Tsinghua University Beijing China Network Research Center Tsinghua University Beijing China

Reputation systems represent soft security mechanisms that complement traditional information security mechanisms. They are now widely used in online e-commerce markets and communities in order to stimulate good behaviors as well as to restrain adverse behaviors. This paper analyzes the limitations of the conversational reputation models and proposes an incentive reputation model called the resilient reputation model （RRM） for the distributed reputation systems. The objective of this reputation model is not only to encourage the users to provide good services and, therefore, to maximize the probability of good transaction outcomes, but also to punish those adverse users who are trying to manipulate the application systems. The simulation results indicate that the proposed reputation model （RRM） could effectively resist against the common adverse behaviors, while protecting the profits of sincere users from being blemished by those adversaries.

关键词： reputation model distributed system trust soft security

On mean curvatures in submanifolds geometry

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Science china Mathematics 2008年第6期51卷 1127-1134页

作者： GE JianQuan department of Mathematical Sciences,tsinghua university,beijing 100084,china department of Mathematical Sciences Tsinghua University Beijing China

By using moving frame theory,first we introduce 2p-th mean curvatures and(2p+1)-th mean curvature vector fields for a *** then give an integral expression of them that characterizes them as mean values of symmetric functions of principle *** we apply it to derive directly the celebrated Weyl-Gray tube formula in terms of integrals of the 2p-th mean curvatures and some Minkowski-type integral formulas.

关键词： moving frame mean curvature tube 53A07 53C42

On fixed-points and singular values of transcendental meromorphic functions

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Science china Mathematics 2010年第3期53卷 887-894页

作者： ZHENG JianHua department of Mathematical Sciences, tsinghua university, beijing 100084, china department of Mathematical Sciences Tsinghua University Beijing China

In this paper we make a further discussion of a relationship between the number of fixed-points and distribution of singular values along the round annuli centered at the origin of a transcendental meromorphic function. To attain our purpose we first establish a fundamental inequality for the modulus of derivative of a holomorphic covering mapping whose image is an annulus by virtue of the hyperbolic metric. The inequality is of independent significance. We make a simple survey on some domain constants for hyperbolic domains.

关键词： meromorphic functions fixed points singular points hyperbolic metric covering mapping

MICROMECHANICAL MODELLING OF STRAIN SOFTENING IN MICROCRACK-WEAKENED QUASI-BRITTLE MATERIALS

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Acta Mechanica Solida Sinica 1995年第2期8卷 121-132页

作者： Feng Xiqiao Yu Shouwen(Dept.of engineering mechanics,tsinghua university,beijing 100084,P.R.china) Dept. of engineering mechanics Tsinghua University Beijing 100084 China

By using the concept of domain of microcrack growth(DMG),the micromechanisms of damage in quasi-brittle materials subjected to triaxial either tensile or compressive loading are investigated and the complete strew-strain relation including four stages is obtained from micromechanical *** regime of pre-peak nonlinear hardening corresponds to the distributed damage,*** stable propagation of *** the attainment of the ultimate strength of load-bearing capacity, some microcracks experience the second unstable growth and the distributed damage is transmitted to the localization of *** analyses improve our understanding of the hardening and softening behaviors of quasi-brittle materials.

关键词： microcracks strain softening constitutive relation micromechanical damage mechanics brittle material

INTERFACIAL REACTIONS OF METAL FILMS WITH AlN SUBSTRATE

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中国有色金属学会会刊：英文版 1996年第2期6卷 81-85页

作者： He Xiangjun Tao Kun Fan Yudian (department of Materials Science and engineering, tsinghua university, beijing 100084) department of Materials Science and engineering Tsinghua University Beijing 100084 China

ＩＮＴＥＲＦＡＣＩＡＬＲＥＡＣＴＩＯＮＳＯＦＭＥＴＡＬＦＩＬＭＳＷＩＴＨＡｌＮＳＵＢＳＴＲＡＴＥＨｅＸｉａｎｇｊｕｎ；ＴａｏＫｕｎ；ＦａｎＹｕｄｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥ... 详细信息

ＩＮＴＥＲＦＡＣＩＡＬＲＥＡＣＴＩＯＮＳＯＦＭＥＴＡＬＦＩＬＭＳＷＩＴＨＡｌＮＳＵＢＳＴＲＡＴＥＨｅＸｉａｎｇｊｕｎ；ＴａｏＫｕｎ；ＦａｎＹｕｄｉａｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉｎｇ，Ｔｓｉｎｇｈ...

关键词： thin films interfacial reactions AlN substrate

Nonlinear Evolution of Aggregates with Inextensible Constraints

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Communications in Nonlinear Science and Numerical Simulation 1996年第3期1卷 8-12页

作者： Ming-Xiang CHEN Wei YANG and Quan-Shui ZHENG(department of engineering mechanics, tsinghua university, beijing 100084, china)E-mail: demyw@tsinghua. edu. cn department of engineering mechanics Tsinghua University Beijing 100084 China

Crystalline and sendcrystalline polymers are formed as aggregates of grainswith evolving inextensible axes. This inextensible constraint leads to texture evolution underlarge plastic deformation, This paper reveals th... 详细信息

关键词： Nonlinear texture evolution crystalline polymers inextensible constraint

THE MEASUREMENT OF PLASTIC DEFORMATION AND CRACK GROWTH IN CRACKED SPECIMENS BY SAM

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Acta Mechanica Solida Sinica 1994年第4期7卷 347-353页

作者： Sun Xuewei Li Mingzheng (department of engineering mechanics,tsinghua university,beijing 100084,P.R.china) department of engineering mechanics Tsinghua University Beijing 100084 China

In this paper,scanning acoustic microscope(SAM) was used to obtain some characteristic photographs which explain the mesoscopic information of several cracked *** results on subsurface information of steel,nickel and aluminium were *** deformation and crack initiation were observed and *** length of crack propagation was *** is particularly suited to the study of many mesoscopic phenomena in material science because it can image mesoscopic subsurface feature without *** is revealed that SAM has a bright future in the field of mesomechanics.

关键词： SAM(scanning acoustic microscope) experiment mesomechanics crack

Theoretical research progress in new-generation Internet architecture

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Science in china(Series F) 2008年第11期51卷 1634-1660页

作者： WU JianPing1,2,3,LIU Ying2,3 & WU Qian2,3 1 department of Computer Science,tsinghua university,beijing 100084,china 2 Network Research Center,tsinghua university,beijing 100084,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,beijing 100084,china department of Computer Science Tsinghua University Beijing China Network Research Center Tsinghua University Beijing China tsinghua National Laboratory for Information Science and Technology (TNList) Beijing China

Internet has become the most important information infrastructure supporting modern socio-economic development, social progress and technological Innovation. Invented 30 years ago, today Internet is facing increasingly severe technical challenges. This paper introduces the progress of the major international newgeneration Internet research plans; analyzes its basic characteristics and the principal contradictions during the development; detsiledly introduces the research carried out by 973 Project ＂Research of Future Internet Architecture＂ on the key scientific issues of new-generation Internet architecture and its latest research results; and looks to the future of the research-focus faced with the new situations of the basic research of new-generation Internet architecture as well as the new demands of innovative applications on Internet architecture.

关键词： new-generation Internet network architecture multi-dimension scalability

A formal method to real-time protocol interoperability testing

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Science in china(Series F) 2008年第11期51卷 1723-1744页

作者： WANG ZhiLiang1,3,YIN Xia2,3 & JING ChuanMing2,3 1 Network Research Center,tsinghua university,beijing 100084,china 2 department of Computer Science and Technology,tsinghua university,beijing 100084,china 3 tsinghua National Laboratory for Information Science and Technology(TNList) ,beijing 100084,china Network Research Center Tsinghua University Beijing China tsinghua National Laboratory for Information Science and Technology (TNList) Beijing China department of Computer Science and Technology Tsinghua University Beijing China

Interoperability testing is an important technique to ensure the quality of implementations of network communication protocol. In the next generation Internet protocol, real-time applications should be supported effectively. However, time constraints were not considered in the related studies of protocol interoperability testing, so existing interoperability testing methods are difficult to be applied in real-time protocol interoperability testing. In this paper, a formal method to real-time protocol interoperability testing is proposed. Firstly, a formal model CMpTIOA （communicating multi-port timed input output automata） is defined to specify the system under test （SUT） in real-time protocol interoperability testing; based on this model, timed interoperability relation is then defined. In order to check this relation, a test generation method is presented to generate a parameterized test behavior tree from SUT model; a mechanism of executability pre-determination is also integrated in the test generation method to alleviate state space explosion problem to some extent. The proposed theory and method are then applied in interoperability testing of IPv6 neighbor discovery protocol to show the feasibility of this method.

关键词： protocol testing interoperability testing real-time testing test generation timed input output automata(TIOA)