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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,{2. 100084,China 2.Department of Computer Science and technology,Tsinghua University,{2. 100084,China 3.Network research center,Tsinghua University,{2. 100084,China 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

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

research of the Gas-solid Flow Character Based on the DEM Method

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Journal of Thermal Science 2011年第6期20卷 521-526页

作者： Xueyao Wang and Yunhan Xiao research center for Clean Energy and Power,Chinese {2. of {3. Key Laboratory of Advanced Energy and Power,Chinese {2. of {3. (Institute of engineering Thermophysics),beijing,100190,China research center for Clean Energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China

Numerical simulation of gas-solid flow behaviors in a rectangular fluidized bed is carried out three dimensionally by the discrete element method (DEM).Euler method and Lagrange method are employed to deal with the gas phase and solid phase *** collided force among particles,striking force between particle and wall,drag force,gravity,Magnus lift force and Saffman lift force are considered when establishing the mathematic ***-sphere model is used to describe the collision of *** addition,the Euler method is also used for modeling the solid phase to compare with the results of *** flow patterns,particle mean velocities,particles' diffusion and pressure drop of the bed under typical operating conditions are *** results show that the DEM method can describe the detailed information among particles,while the Euler-Euler method cannot capture the micro-scale *** matter which method is used,the diffusion of particles increases with the increase of gas *** the gathering and crushing of particles cannot be simulated,so the energy loss of particles' collision cannot be calculated and the diffusion by using the Euler-Euler method is *** addition,it is shown by DEM method,with strengthening of the carrying capacity,more and more particles can be schlepped upward and the dense suspension upflow pattern can be ***,the results given by the Euler-Euler method are not consistent with the real situation.

关键词： DEM gas-solid flow numerical simulation

Relative position determination of a lunar rover using high-accuracy multi-frequency same-beam VLBI

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 571-578页

作者： LIU QingHui1, CHEN Ming1, XIONG WeiMing2. QIAN ZhiHan1, LI JinLing1, HAO WangHong1,4, WANG GuangLi1, ZHENG WeiMin1, GUAN Di3. ZHU RenJie1, WANG WeiHua1, ZHANG XiuZhong1, JIANG DongRong1, SHU FengChun1, PING JinSong1 & HONG XiaoYu11 Shanghai Astronomical Observatory, Chinese academy of sciences, Shanghai 2.003., China 2.{2. for Space Science and Applied {3., Chinese academy of sciences, beijing 100190, China 3.Lunar Explorer engineering General Department, Chinese academy of sciences, beijing 100012. China 4 beijing Institute of Tracking and Telecommunications {12., beijing 100094, China 1. Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China2. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China4. Beijing Institute of Tracking and Telecommunications Technology Beijing 100094 China3. Lunar Explorer Engineering General Department Chinese Academy of Sciences Beijing 100012 China

Multi-frequency same-beam VLBI means that two explorers with a small separation angle are simultaneously observed with the main beam of receiving antennas. In the same-beam VLBI, the differential phase delay between two explorers and two receiving telescopes can be obtained with a small error of several picoseconds. The differential phase delay, as the observable of the same-beam VLBI, gives the separation angular information of the two explorers in the celestial sphere. The two-dimensional relative position on the plane-of-sky can thus be precisely determined with an error of less than 1 m for a distance of 3.8×105 km far away from the earth, by using the differential phase delay obtained with the four Chinese VLBI stations. The relative position of a lunar rover on the lunar surface can be determined with an error of 10 m by using the differential phase delay data and the range data for the lander when the lunar topography near the rover and the lander can be determined with an error of 10 m.

关键词： same-beam VLBI differential phase delay relative position determination lunar rover

P2. traffic optimization

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Science China(information sciences) 2012年第7期55卷 1475-1492页

作者： ZHANG GuoQiang 1,2.,TANG MingDong 3.,CHENG SuQi 2.4 ,ZHANG GuoQing 2.,SONG HaiBin 5 ,CAO JiGuang 6 & YANG Jing 7 1 School of Computer Science and {3.,Nanjing Normal University,Nanjing 2.0046,China 2.Institute of Computing {3.,Chinese {2. of {3.,beijing 100190,China 3.School of Computer Science and engineering,Hunan University of Science and {3.,Xiangtan 4112.1,China 4 Graduate University of Chinese {2. of {3.,beijing 100190,China 5 Nanjing R&D center,Huawei Technologies,Nanjing 2.0012.China 6 China {2. of Telecommunication {12. of MIIT,beijing 100191,China 7 China Mobile {12. Institute,beijing 100053.China 1. School of Computer Science and technology Nanjing Normal University Nanjing 210046 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China3. School of Computer Science and Engineering Hunan University of Science and Technology Xiangtan 411201 China4. Graduate University of Chinese Academy of Sciences Beijing 100190 China5. Nanjing R&D Center Huawei Technologies Nanjing 210012 China6. China Academy of Telecommunication Research of MIIT Beijing 100191 China7. China Mobile Research Institute Beijing 100053 China

Peer-to-peer (P2.) based content distribution systems have emerged as the main form for content distribution on the Internet,which can greatly reduce the distribution cost of content providers and improve the overall system ***,the mismatch between the overlay and underlay networks causes large volume of redundant traffic,which intensifies the tension between P2. content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2. *** paper surveys the state-of-art P2. traffic optimization technologies from three perspectives:P2. cache,locality-awareness and data *** details,comparison between these technologies and their applicabilities are presented,followed by a discussion of the issues that remain to be addressed and the direction of future content distribution research.

关键词： P2. traffic localization P2. traffic optimization P2. cache locality-awareness network coding content-centric network

A novel logic-based automatic approach to constructing compliant security policies

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Science China(information sciences) 2012年第1期55卷 149-164页

作者： BAO YiBao1,2.4,YIN LiHua1,FANG BinXing 1,3.GUO Li 1 1Institute of Computing technology,Chinese academy of {2.,{3. 100190,China 2.nstitute of Electronic technology,information engineering University,Zhengzhou 450004,China 3.4} University of Posts and Telecommunications,{3. 100190,China 4Graduate University,the Chinese academy of Science,{3. 100049,China 1. Institute of Computing technology Chinese Academy of Sciences Beijing 100190 China2. Institute of Electronic Technology Information Engineering University Zhengzhou 450004 China4. Graduate University the Chinese Academy of Science Beijing 100049 China3. Beijing University of Posts and Telecommunications Beijing 100190 China

It is significant to automatically detect and resolve the incompliance in security *** existing works in this field focus on compliance verification,and few of them provide approaches to automatically correct the incompliant security *** paper proposes a novel approach to automatically transform a given security policy into a compliant *** security policy Π and delegation policy M declared by logic programs,the approach automatically rewrites Π into a new one ΠM which is compliant with M and is readable by the *** prove that the algorithm is sound and complete under noninterference ***,we show that the security policy query evaluation algorithm with conflict and unsettlement resolution still works very well on Π*** approach is automatic,so it doesn't require a administrator with excess *** this sense,our proposal can help us to save much manpower resource in security management and improves the security assurance abilities.

关键词： security policy rewriting logic program compliance

Spray and forward:Efficient routing based on the Markov location prediction model for DTNs

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Science China(information sciences) 2012年第2期55卷 433-440页

作者： DANG Fei1,YANG XiaoLong1,2.& LONG KePing2.1 research {3. for Optical Internet and Mobile {2. Networks(COIMIN),University of Electronic Science and {3. of China,Chengdu 61173.,China 2.School of Computer and Communications engineering,University of Science and {3. beijing,beijing 100083.China 1. research center for Optical Internet and Mobile {2. Networks (COIMIN) University of Electronic Science and Technology of China Chengdu 611731 China2. School of Computer and Communications Engineering University of Science and Technology Beijing Beijing 100083 China

Typical delay tolerant networks(DTNs)often suffer from long and variable delays,frequent connectivity disruptions,and high bit error *** DTNs,the design of an efficient routing algorithm is one of the key *** existing methods improve the accessibility probability of the data transmission by transmitting many copies of the packet to the network,but they may cause a high network *** address the tradeoff between a successful delivery ratio and the network overhead,we propose a DTN routing algorithm based on the Markov location prediction model,called the spray and forward routing algorithm(SFR).Based on historical information of the nodes,the algorithm uses the second-order Markov forecasting mechanism to predict the location of the destination node,and then forwards the data by greedy routing,which reduces the copies of packets by spraying the packets in a particular *** contrast to a fixed mode where a successful-delivery ratio and routing overhead are contradictory,a hybrid strategy with multi-copy forwarding is able to reduce the copies of the packets efficiently and at the same time maintain an acceptable successful-delivery *** simulation results show that the proposed SFR is efficient enough to provide better network performance than the spray and wait routing algorithm,in scenarios with sparse node density and fast mobility of the nodes.

关键词： delay tolerant networks spray and forward Markov position prediction routing algorithm

Risk analysis model for landslide mass of high slope in dam area

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Science China(Technological sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2.HE XianFeng3.4,WU ZhongRu1,2.& SU HuaiZhi1,2.1 College of Water Conservancy and Hydropower {3.,Hohai University,Nanjing 2.0098,China 2.National {3. {2. {3. of Water Resources Efficient Utilization and {3. Safety,Nanjing 2.0098,China 3.Yellow River Institute of Hydraulic {2.,Zhengzhou 450003.China 4 Embankment security Defect Prevention and Control {3. {2. {3. of MWR,Zhengzhou 450003.China 1. College of Water Conservancy and Hydropower engineering Hohai University Nanjing 210098 China 2. National engineering research {2. of Water Resources Efficient Utilization and engineering Safety Nanjing 210098 China 3. Yellow River Institute of Hydraulic research Zhengzhou 450003 China 4. Embankment security Defect Prevention and Control engineering {2. {3. of MWR Zhengzhou 450003 China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

Integral ear elimination and virtual point-based updating algorithms for constrained Delaunay TIN

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Science China(Technological sciences) 2008年第S1期51卷 135-144页

作者： WU LiXin1,2.WANG YanBing2.3.& SHI WenZhong2.4 1 Institute for Geo-informatics & Digital Mine {3.,Northeastern University,Shenyang 110004,China 2.Institute for GIS/RS/GPS & Subsidence engineering {3.,China University of Mining & {3.,beijing 100085,China 3.Laboratory of 3. information Acquisition & Application,Capital Normal University,beijing 10003.,China 4 center for Advanced GIS {3.,LSGI,Polytechnic University Hong Kong,Hong Kong,China Northeastern Univ Inst Geoinformat & Digital Mine Res Shenyang 110004 Peoples R China China Univ Mining & Technol Inst GIS RS GPS & Subsidence Engn Res Beijing 100085 Peoples R China Capital Normal Univ Lab Informat Acquisit & Applicat Beijing 100037 Peoples R China Hong Kong Polytech Univ LSGI Ctr Adv GIS Res Hong Kong Hong Kong Peoples R China

Constrained Delaunay Triangular Irregular Networks (CD-TIN),a kind of special data structure,have many practical applications in Geoinformatics,especially in the representation of linear constrained triangulation for DTM and DSM,such as in digital city and digital mine. Past researches on D-TIN mainly focused on point in-sertion and deletion without consideration of constraint,and that on CD-TIN usu-ally paid more attention to the insertion algorithms for points and edges,but little to the deletion algorithms. The presented algorithms are far insufficient for the dy-namic updating of CD-TIN. In this paper,the constraint edge in CD-TIN is consid-ered to be any set of broken lines,i.e.,polygon edges,broken lines and simple segments. The constraint edge may be composed of one or more constraint seg-ments,and it is allowed to be in any form: Open or close,intersection or self-in-tersection. By improving to present insertion and deletion algorithms for D-TIN,two new algorithms for CD-TIN updating are presented. According to the polymorphism of the constraints in CD-TIN,virtual point is adopted to represent the crossing node between constraint edges when a constraint edge is inserted in CD-TIN. Two new algorithms named as Integral Ear Elimination (IEE) and Influence Domain Retrian-gulation for Virtual Point (IDRVP) are presented,the former is for constraint point deletion,while the later is for the insertion and deletion of constraint edge. The principle of IDRVP is that to divide the influence domain of a virtual point into some parts by the constraint-keeping edges,and to retriangulate each part of the influ-ence domain individually referring to the constraint visible property and constraint empty circle (CEC) criterion. Finally,a prototype system is developed with VC++,one case on the integration of 3. terrain and buildings is demonstrated to test the correctness of new algorithms. It shows that the new algorithms are effective for the updating of CD-TIN.

关键词： Delaunay TIN spatial constraint data updating spatial modeling polymorphism digital mine

ON DECORRELATED FAST CIPHER

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Journal of Electronics(China) 2000年第1期17卷 94-96页

作者： Wu Wenling Li Bao Feng Denguo Qing Sihan(engineering research {2. for {3. security technology,Chinese academy of sciences, beijing 100080)

Decorrelated Fast Cipher(DFC) is a candidate for the Advanced Encryption Standard (AES). It is shown that the cryptographic properties of the confusion permutation of DFC are weak in this paper. With the same F-function of DFC, a Feistel cipher VDFC which has no resistance against differential cryptanalysis is constructed. This demonstrates the importance of the key addition into DFC sufficiently. As a result, DFC may not be qualified candidate for the AES.

关键词： Round function Permutation Differential cryptanalysis Nonlinearity