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Presenting degenerate Ringel-Hall algebras of type B

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science china Mathematics 2012年第5期55卷 949-960页

作者： FAN LiJuan1 & ZHAO ZhongHua2,1Department of Mathematics,beijing Normal university,beijing 100875,{3. 2Department of Mathematics and computer science,School of science,beijing university of Chemical technology,beijing 100029,{3. 1. Department of Mathematics Beijing Normal University Beijing 100875 China2. Department of Mathematics and Computer Science School of Science Beijing University of Chemical Technology Beijing 100029 China

We give a presentation for the degenerate Ringel-Hall algebras of type B by studying the corresponding generic extension monoid *** an application,it is shown that the degenerate Ringel-Hall algebras of type B admit m... 详细信息

关键词： degenerate Ringel-Hall algebras generic extension monoid algebras Auslander-Reiten quivers Frobenius morphism

Complexity of synthesis of composite service with correctness guarantee

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science china(Information sciences) 2012年第3期55卷 638-649页

作者： DENG Ting1,2 , HUAI JinPeng1,3.& WO TianYu1,3.1State Key Laboratory of Software Development Environment, Beihang university beijing 100191, china 2School of Mathematics and System {3., Beihang university, beijing 100191, china 3.chool of computer {3. and Engineering, Beihang university, beijing 100191, china 1. State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China2. School of Mathematics and System Science Beihang University Beijing 100191 China3. School of Computer Science and Engineering Beihang University Beijing 100191 China

How to compose existing web services automatically and to guarantee the correctness of the design (e.g. temporal constraints specified by temporal logic LTL, CTL or CTL*) is an important and challenging problem in web services. Most existing approaches use the process in conventional software development of design, verification, analysis and correction to guarantee the correctness of composite services, which makes the composition process both complex and time-consuming. In this paper, we focus on the synthesis problem of composite service; that is, for a given set of services and correctness constraint specified by CTL or CTL* formula, a composite service is automatically constructed which guarantees that the correctness is ensured. We prove that the synthesis problem for CTL and CTL* are complete for EXPTIME and 2EXPTIME, respectively. Moreover, for the case of synthesis failure, we discuss the problem of how to disable outputs of environment (i.e. users or services) reasonably to make synthesis successful, which are also proved complete for EXPTIME and 2EXPTIME for CTL and CTL*, respectively.

关键词： business protocol composite service synthesis environment branching temporal logic

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 Center for Optical Internet and Mobile Information 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 Information 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

Application of Potentiostats Using PC in the Phase Analysis of Galvano-Chemis-try

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International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 151-153页

作者： Bo wen Xinyu Liu Xinhua Wang Wanjun Wang Xang Ma(Information Engineering School, university of science and {3. beijing, beijing 100083. china)(Metallurgy School, university of science and {3. beijing, beijing 100083. china)(beijing Resea Univ Sci & Technol beijing Informat Engn Sch Beijing 100083 Peoples R China Univ Sci & Technol beijing Met Sch Beijing 100083 Peoples R China beijing Res Inst Iron & Steel Beijing 100081 Peoples R China

A set of device is designed based on PC to realize the functions of traditional potentiostats in the phase ana1ysis of galvanochemistry. In the device, A/D and D/A conversion is used to measure the electrode potential and convert the voltage for outPut; specific program runs in the PC to regulate and control the system. The effect of the proportion factor Kp on the control variation is researched through certain experiment. Two experiments, the control of electrolysis in constant poteniial and the determination of polarization curves, are designed to test and evaluate the effectiveness of the device. The experimemel results show that the variation between the actualanode potential and the target potential could be controlled to below 1 mV if Kp is set to an appropriate value.

关键词： potentiostat PC phase analysis of galvano-chemistry

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A new heuristic algorithm for the circular packing problem with equilibrium constraints

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science china(Information sciences) 2011年第8期54卷 1572-1584页

作者： LIU JingFa 1,2,LI Gang 3.& GENG HuanTong 1 1 School of computer and Software,Nanjing university of Information science & {3.,Nanjing 210044,china 2 Network Information Center,Nanjing university of Information science & {3., Nanjing 210044,china 3.School of Mathematics and Physics,Nanjing university of Information science & {3.,Nanjing 210044,china 1. School of computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China2. Network Information Center Nanjing University of Information Science & Technology Nanjing 210044 China3. School of Mathematics and Physics Nanjing University of Information Science & Technology Nanjing 210044 China

The circular packing problem with equilibrium constraints is an optimization problem about simplified satellite module layout design.A heuristic algorithm based on tabu search is put forward for solving this *** algorithm begins from a random initial configuration and applies the gradient method with an adaptive step length to search for the minimum energy *** jump out of the local minima and avoid the search doing repeated work,the algorithm adopts the strategy of tabu *** the process of tabu search,we improve the traditional neighboring solutions,tabu objects and the acceptance criteria of the current solution *** test two sets of benchmarks consisting of 11 representative instances from the current *** numerical results show that the proposed algorithm breaks the records in seven out of 11 instances,and obtains the optimal solutions for the other four instances.

关键词： equilibrium constraints packing problem heuristic algorithm tabu search layout optimization

Radiance-based color calibration for image-based modeling with multiple cameras

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science china(Information sciences) 2012年第7期55卷 1509-1519页

作者： ZHAO Xu 1,2 ,ZHOU Zhong 1,2 & WU Wei 1,2 1 State Key Laboratory of Virtual Reality technology and Systems,Beihang university,beijing 100191,{3. 2 School of computer science and Engineering,Beihang university,beijing 100191,{3. 1. State Key Laboratory of Virtual Reality technology and Systems Beihang University Beijing 100191 China2. School of Computer Science and Engineering Beihang University Beijing 100191 China

Photo-consistency estimation is an important part for many image-based modeling *** paper presents a novel radiance-based color calibration method to reduce the uncertainty of photo-consistency estimation across multiple *** idea behind our method is to convert colors into a uniform radiometric color space in which multiple image data are *** results demonstrate that our method can achieve comparable color calibration effect without adjusting camera parameters and is more robust than other existing ***,we obtain an auto-determined threshold for photo-consistency check,which will lead to a better performance than existing photo-consistency based reconstruction algorithms.

关键词： color calibration photo-consistency estimation multi-camera system image-based modeling

Nontrivial homoclinic orbits for second-order singular and periodic Hamiltonian systems

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Chinese science Bulletin 1999年第2期44卷 123-129页

作者： LI Chengyue , FAN Tianyou TONG MingshengResearch Center of Materials science, beijing Institute of technology, beijing 100081, china Department of Mathematics, Central university for Nationalities, beijing 100081, china computer Center, beijing Institute of technology, beijing 100081, china Research Center of Materials science Beijing Institute of Technology Beijing China Department of Mathematics Central University for Nationalities Beijing China computer Center Beijing Institute of Technology Beijing China

The existence of nontrivial homoclinic orbits of periodic Hamiltonian systems: is proved, where q=（q1,q2,’',qn）, n>2; V（t, q）:R1×Rn\{e}→R1 is a potential With a singularity, i.e. -V（t, q）→+∞, as q→e. The m... 详细信息

关键词： Hamiltonian systems strong force condition homoclinic orbit.

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Seamlet carving for shape-aware image resizing

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science china(Information sciences) 2012年第5期55卷 1073-1081页

作者： LIN Xiao 1,2,SHENG Bin 1,MA LiZhuang 1,SHEN yang 1 & CHEN ZhiHua 3.1 Department of computer science and Engineering,Shanghai Jiao Tong {3.,Shanghai 200240,china 2 Academy of Information technology,Luoyang Normal {3.,Luoyang 471022,china 3.Department of computer science and Engineering,East china {3. of science and technology,Shanghai 20023.,china 1. Department of computer science and Engineering Shanghai Jiao Tong University Shanghai 200240 China2. Academy of Information Technology Luoyang Normal University Luoyang 471022 China3. Department of Computer Science and Engineering East China University of Science and Technology Shanghai 200237 China

In this paper we propose an optimized seam-carving approach for anti-shearing image *** image/video seam-carving strategy only focuses on deleting the pixels along 8-connected seams,which may lead to the obvious information loss during *** the traditional seam-carving methods,our approach can construct a seamlet to handle the discontinuous pixels and further achieve an optimized image resizing results with *** particular,to suppress zigzag artifacts,we introduce the anti-shearing energy into the seamlet generation,which includes two steps:1) the energy map is formalized by using Gabor filtering and the saliency map;2) The energy computation is optimized in Gabor feature space to obtain the resizing results without the connectivity *** experimental results and comparisons show the effectiveness of our method.

关键词： image resizing seamlet carving saliency map

P2P 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 210046,china 2 Institute of Computing {3.,Chinese Academy of sciences,beijing 100190,china 3.School of computer science and Engineering,Hunan university of science and {3.,Xiangtan 411201,china 4 Graduate university of Chinese Academy of sciences,beijing 100190,china 5 Nanjing R&D Center,Huawei Technologies,Nanjing 210012,china 6 china Academy of Telecommunication Research of MIIT,beijing 100191,china 7 china Mobile Research 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 (P2P) 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 P2P content providers and ***,how to efficiently use network resources to reduce the traffic burden on the ISPs is crucial for the sustainable development of P2P *** paper surveys the state-of-art P2P traffic optimization technologies from three perspectives:P2P 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： P2P traffic localization P2P traffic optimization P2P cache locality-awareness network coding content-centric network