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On the interannual variation in spring atmospheric inter-hemispheric oscillation linked to synchronous climate in china

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Progress in Natural science:Materials International 2009年第9期19卷 1125-1131页

作者： Chuhan Lu, Zhaoyong Guan * Key laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric sciences, Nanjing University of information science and technology, Nanjing 210044, china [a]Key laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China

Based on NCEP/NCAR monthly mean reanalysis data and surface observations of Chinese stations, inter-hemispheric oscillations (IHO) of spring atmospheric mass on an interannual basis in conjunction with the linkage to the synchronous climate over china are studied. Results suggest that the spring IHO exhibits a significant seesaw pattern for air mass at bi-hemispheric mid-high latitudes, with a consistent vertical circulation structure. The EOF decomposition of zonally mean surface pressures without signals of Arctic Oscillation (AO) and Antarctic Oscillation (AAO) indicates that the EOF1 IHO feature is remarkable, with the corresponding time coeficients correlated with the spring IHO index (IIHO) at 0.93. the spring IHO bears a close relation to the synchronous climate in china, showing the surface pressure, temperature and relative humidity over the country to be in good correlation with IIHO; the spring duststorms in Qinghai, Gansu, Shaanxi and Inner Mongolia have bearing on IHO. Positive-phase IIHO promotes the strengthening of the Siberian high, during which zonal winds between 60°E and 150°W show a longitudinal teleconnection structure extending from the Arctic to Antarctica, leading to positive westerly wind anomalies over Asia, affecting the spring climate of china.

关键词： Air mass Inter-hemispheric oscillation (IHO) Spring climate china

Bayesian cognitive trust model based self-clustering algorithm for MANETs

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science china(information sciences) 2010年第3期53卷 494-505页

作者： WANG Wei1,2,3.& ZENG GuoSun1,2,3.Department of Computer science & technology, Tongji University, Shanghai 200092, china 2Tongji Branch, {3. Engineering & technology Center of High Performance Computer, Shanghai 200092, china 3.ey Loboratory of Embedded System and Service Computing, Ministry of Education, Shanghai 200092, china 1. Department of Computer science & technology Tongji University Shanghai 200092 China2. Tongji Branch National Engineering & Technology Center of High Performance Computer Shanghai 200092 China3. Key Loboratory of Embedded System and Service Computing Ministry of Education Shanghai 200092 China

With the introduction of mobile Ad hoc networks (MANETs), nodes are able to participate in a dynamic network which lacks an underlying infrastructure. Before two nodes agree to interact, they must trust that each will satisfy the security and privacy requirements of the other. In this paper, using the cognition inspired method from the brain informatics (BI), we present a novel approach to improving the search efficiency and scalability of MANETs by clustering nodes based on cognitive trust mechanism. The trust relationship is formed by evaluating the level of trust using Bayesian statistic analysis, and clusters can be formed and maintained autonomously by nodes with only partial knowledge. Simulation experiments show that each node can form and join proper clusters, which improve the interaction performance of the entire network. The essence of the underlying reason is analyzed through the theory of complex networks, revealing great scalability of this method.

关键词： trust model MANET self-clustering Bayesian method cognitive mobile

Error exponents for two-hop Gaussian multiple source-destination relay channels

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science china(information sciences) 2012年第2期55卷 348-359页

作者： DENG PanLiang1,3.LIU YuanAn1,3.XIE Gang2,3.WANG XiaoYu1,3.TANG BiHua1,3.& SUN JianFeng1,3.1School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,china 2School of information and Communication Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,china 3.ey {3. of Universal Wireless Communication,Ministry of Education,Beijing 100876,china 1. School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Laboratory of Universal Wireless Communication Ministry of Education Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

We investigate the two-hop multiple source-destination relay channels using the rate splitting trans-mission scheme where each source can split its message into private and public *** determine the system error probability via integrated exponent function under amplify-and-forward(AF)and decode-and-forward(DF)relay *** most significant difference between AF and DF system error probability evaluations lies in a minimized cut-set bound of transmission rate under the DF *** are many cases among transmission rate intervals for different system parameters(*** power)and it is extremely complex to derive the system error probability for the DF *** obtain a relatively simple result,which unifies various cases by a few *** results show that the system error probability decreases with the increase of the public ***,in order to draw deep insight into the reliability requirement of each source node in this network,we provide the error exponent region(EER)for different source nodes to show the trade-off of error probability among source nodes.

关键词： error exponent error exponent region rate splitting multiple source-destination relay channel

Polling Algorithm Based on Traffic Burst Characteristics of Broadband Wireless Access Systems

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Journal of Shanghai Jiaotong university(science) 2011年第4期16卷 429-435页

作者：李秀媛李炜吴晓娟张云峰 School of Computer science and technology Shandong Economy University School of information science and Engineering Shandong University Shandong Provincial Key laboratory of Digital Media technology

In this paper,we propose a novel polling algorithm to decrease the number of idle slots and collission slots during the polling cycle by evaluating the bandwidth request of the subscribe stations(SSs) in the next polling cycle for broadband wireless access(BWA) *** firstly analyze the feature of silent time intervals and deduce the Hurst index which symbolizes the degree of self-similarity and long-relative *** we represent the inactive OFF time intervals by the Pareto model and estimate the shape parameterαby the group measured *** we can evaluate the transmission probability of a silent SS before the next polling cycle. By this algorithm,we can find the optimal transmission opportunities for the base station(BS) to achieve the least collision or void timeslots in order to achieve the largest bandwidth *** theoretical analysis and simulation results show that this polling algorithm can improve the performance for BWA system.

关键词： broadband wireless access(BWA) systems polling algorithm bandwidth allocation self-similarity

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Research on trusted computing and its development

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science china(information sciences) 2010年第3期53卷 405-433页

作者： SHEN ChangXiang1, ZHANG HuanGuo1?, WANG HuaiMin3. WANG Ji3. ZHAO Bo2, YAN Fei2, YU FaJiang2, ZHANG LiQiang2 & XU MingDi21Beijing University of technology, Beijing 100124, china 2School of Computer, Wuhan University, Key laboratory of Aerospace {3. Security and Trusted Computing of Ministry of Education, Wuhan 43.072, china 3.chool of Computer, national University of Defence technology, Changsha 43.074, china 1. Beijing University of technology Beijing 100124 China3. School of Computer National University of Defence Technology Changsha 430074 China2. Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education School of Computer Wuhan University Wuhan 430072 China

Trusted computing is a novel technology of information system security. It has become a new tide in worldwide information security area and achieved inspiring accomplishment. In {3., the initiative research of trusted computing is not late, and the achievements are plentiful and substantial. Our country is in the front rank of the world in trusted computing. This paper comprehensively illustrates the recent development in theory and technology of trusted computing, introduces some improvements in trusted computing in our country, and proposes our opinions and viewpoints towards the existing problems in trusted computing and its future development.

关键词： information security trusted computing trusted computing platform trustworthy software trusted network connection

Dense coding scheme using superpositions of Bell-states and its NMR implementation

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science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key laboratory for Quantum information and Measurements, Department of Physics, tsinghua University, Beijing 100084, {3. Center for Quantum information, tsinghua University, Beijing 100084, {3. Department of Materials science and Engineering, Beijing Normal University, Beijing 100875, {3. Testing and Analytical Center, Beijing Normal University, Beijing 100875, {3. Department of Physics, Beijing Normal University, Beijing 100875, {3. 1. Key laboratory for Quantum information and Measurements Department of Physics Tsinghua University 100084 Beijing China 2. Center for Quantum information Tsinghua University 100084 Beijing China 3. Department of Materials science and Engineering Beijing Normal University 100875 Beijing China 4. Testing and Analytical Center Beijing Normal University 100875 Beijing China 5. Department of Physics Beijing Normal University 100875 Beijing China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

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On the construction of multi-output Boolean functions with optimal algebraic immunity

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science china(information sciences) 2012年第7期55卷 1617-1623页

作者： ZHANG Jie 1,2 ,SONG ShouChao 1 ,DU Jiao 2,3.& WEN QiaoYan 2 1 School of science,Beijing University of Posts and Telecommunications,Beijing 100876,china 2 State Key laboratory of Networking and Switching {3.,Beijing University of Posts and Telecommunications,Beijing 100876,china 3.Department of Mathematics,Xinxiang University,Xinxiang 453.03.china 1. School of science Beijing University of Posts and Telecommunications Beijing 100876 China2. State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China3. Department of Mathematics Xinxiang University Xinxiang 453003 China

In this paper,we show a construction of multi-output Boolean functions with optimal algebraic ***,the relationship between the algebraic immunity of a multi-output Boolean function and those of its component functions is *** show that all the component functions,together with their nonzero linear combination,of the multi-output Boolean functions achieved by this construction have optimal algebraic immunity simultaneously.

关键词： algebraic immunity Boolean functions algebraic attacks annihilators

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Lp shape deformation

science china(information sciences) 2012年第5期55卷 983-993页

作者： GAO Lin1,ZHANG GuoXin 1 & LAI YuKun 2 1 Department of Computer science and technology,tsinghua University,Beijing 100084,{3. 2 School of Computer science and Informatics,Cardiff University,Wales CF24 3.A,UK 1. Department of Computer science and technology Tsinghua University Beijing 100084 China2. School of Computer Science and Informatics Cardiff University Wales CF24 3AA UK

Shape deformation is a fundamental tool in geometric *** methods consider preserving local details by minimizing some energy functional measuring local distortions in the L 2 *** strategy distributes distortions quite uniformly to all the vertices and penalizes ***,there is no unique answer for a natural deformation as it depends on the nature of the *** by recent sparse signal reconstruction work with non L 2 norm,we introduce general L p norms to shape deformation;the positive parameter p provides the user with a flexible control over the distribution of unavoidable *** with the traditional L 2 norm,using smaller p,distortions tend to be distributed to a sparse set of vertices,typically in feature regions,thus making most areas less distorted and structures better *** the other hand,using larger p tends to distribute distortions more evenly across the whole *** flexibility is often desirable as it mimics objects made up with different *** specifying varying p over the shape,more flexible control can be *** demonstrate the effectiveness of the proposed algorithm with various examples.

关键词： shape deformation Lp norm geometric modeling

The optimization of replica distribution in the unstructured overlays

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science china(information sciences) 2012年第3期55卷 714-722页

作者： FENG GuoFu1,2 , LI WenZhong2, LU SangLu2, CHEN DaoXu2 & BUYYA Rajkumar3.1School of information science, Nanjing Audit University, Nanjing 210029, china 2State Key {3. of Novel Software technology, Nanjing University, Nanjing 210093. china 3.epartment of Computer science and Software Engineering, The University of Melbourne, Victoria 3.10, Australia 1. School of information science Nanjing Audit University Nanjing 210029 China2. State Key Laboratory of Novel Software Technology Nanjing University Nanjing 210093 China3. Department of Computer Science and Software Engineering The University of Melbourne Victoria 3010 Australia

Replication is a widely used technique in unstructured overlays to improve content availability or system performance. A fundamental question often addressed by previous work focused on: how many replicas ought to be allocated for each data item given the fixed query rates and limited storage capability? In this paper, we have put forth two optimal replica distributions to achieve the highest success rate and the lowest message consumption. Especially, we have investigated the influence of item size on replica distribution. Our results show that Square-Root Replication, which is traditionally considered to be optimal, is not always the best choice. Our study offers a new deep understanding of resource managment in self-organized unstructured overlays.

关键词： unstructured overlay item size distribution query rate success rate expected search size