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A new scheme of digital communication using chaotic signals in MIMO channels

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Science china(Information Sciences) 2012年第10期55卷 2183-2193页

作者： MA HuanFei 1 & KAN HaiBin 2 1 school of Mathematical Sciences,Soochow university,Suzhou 215006,china 2 school of computer Science,Fudan university,Shanghai 200433,china 1. school of Mathematical Sciences Soochow University Suzhou 215006 China 2. school of computer Science Fudan University Shanghai 200433 China

This paper proposes a new digital communication scheme,which uses chaotic signals based on the adaptive synchronization and parameter identification technique of chaotic systems reported *** to the multi signal character,this scheme combines the chaotic signal transmission with the MIMO channel technique in a wireless environment,which is different from the traditional chaotic communication *** a practical perspective,an outline of modulation,channel model,demodulation and non-coherent detection is ***,system performance is evaluated by simulations,and improvements on this scheme are also discussed.

关键词： chaotic modulation chaotic digital communication mapping parameters MIMO channel

△-tame quasi-hereditary algebras

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Science china mathematics 2007年第2期50卷 240-252页

作者： Yun-ge XU & Ying-bo ZHANG Faculty of mathematics and computer Science, Hubei university, Wuhan 430062, china school of mathematics Sciences, Beijing Normal university, Beijing 100875, china Faculty of mathematics and computer Science Hubei University Wuhan China school of mathematics Sciences Beijing Normal University Beijing China

Let (K, M,H) be an upper triangular bimodule problem. Briistle and Hille showed that the opposite algebra A of the endomorphism algebra of a projective generator P of the matrices category of (K., M, H) is quasi-hereditary, and there is an equivalence between the category of△-good modules of A and Mat(K, M). In this note, based on the tame theorem for bimodule problems, we show that if the algebra A associated with an upper triangular bimodule problem is of△-tame representation type, then the category F(△) has the homogeneous property, i.e. almost all modules in F(△) are isomorphic to their Auslander-Reiten translations. Moreover, if (K, M,H)is an upper triangular bipartite bimodule problem, then A is of△-tame representation type if and only if F(△) is homogeneous.

关键词： bimodule problem quasi-hereditary algebra △-tameness homogeneity.

Basin filling algorithm for the circular packing problem with equilibrium behavioral constraints

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Science china(Information Sciences) 2010年第5期53卷 885-895页

作者： LIU JingFa1& LI Gang2 1school of computer and Software, Nanjing university of Information Science & Technology, Nanjing 210044, china 2school of mathematics and Physics, Nanjing university of Information Science & Technology, Nanjing 210044, china 1. school of computer and Software Nanjing University of Information Science & Technology Nanjing 210044 China2. School of Mathematics and Physics Nanjing University of Information Science & Technology Nanjing 210044 China

With the background of the satellite module layout design, the circular packing problem with equilibrium behavioral constraints is a layout optimization problem and NP-hard problem in math. For lack of a powerful optimization method, this problem is hard to solve. The energy landscape paving (ELP) method is a class of stochastic global optimization algorithms based on the Monte Carlo sampling. Based on the quasiphysical strategy and the penalty function method, the problem is converted into an unconstrained optimization problem. Here by combining the improved ELP method, the gradient method based on local search and the heuristic configuration update mechanism, a new global search algorithm, basin filling algorithm, is put forward. The numerical results show that the proposed algorithm is effective to solving the circular packing problem with equilibrium behavioral constraints, and is easy to be popularized to other layout optimization problems.

关键词： equilibrium behavioral constraints packing problem layout optimization

On Hua-Tuan's conjecture

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Science china mathematics 2009年第2期52卷 389-393页

作者： ZHANG QinHai & QU HaiPeng school of mathematics and computer Sciences, Shanxi Normal university, Linfen 041004, china 1. school of mathematics and computer Sciences Shanxi Normal University Linfen 041004 China

Let G be a finite group and |G| = pn, p be a prime. For 0 m n, sm(G) denotes the number of subgroups of of order pm of G. Loo-Keng Hua and Hsio-Fu Tuan have ever conjectured: for an arbitrary finite p-group G, if p > 2, then sm(G) ≡ 1, 1 + p, 1 + p + p2 or 1 + p + 2p2 (mod p3). In this paper, we investigate the conjecture, and give some p-groups in which the conjecture holds and some examples in which the conjecture does not hold.

关键词： Hua-Tuan’s conjecture metacyclic p-groups abelian p-groups inner abelian p- groups superspecial p-groups

LOW ORDER NONCONFORMING RECTANGULAR FINITE ELEMENT METHODS FOR DARCY-STOKES PROBLEMS

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Journal of Computational mathematics 2009年第Z1期 400-424页

作者： Shiquan Zhang school of mathematics,Sichuan university,chengdu 610064,china Xiaoping Xie Yangtze Center of mathematics and school of mathematics,Sichuan university,chengdu 610064,china Yumei Chen school of mathematics,Sichuan university,chengdu 610064,china College of mathematics and Information,china West Normal university,Nanchong 637002,china

In this paper,we consider lower order rectangular finite element methods for the sin-gularly perturbed Stokes *** model problem reduces to a linear Stokes problemwhen the perturbation parameter is large and degenerates to a mixed formulation of Pois-son’s equation as the perturbation parameter tends to *** propose two 2D andtwo 3D nonconforming rectangular finite elements,and derive robust discretization *** experiments are carried out to verify the theoretical results.

关键词： Darcy-Stokes problem Finite element Uniformly stable

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 Technology of china,chengdu 611731,china 2 school of computer and Communications engineering,university of Science and Technology 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

Theory and techniques of data mining in CGF behavior modeling

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Science china(Information Sciences) 2011年第4期54卷 717-731页

作者： YIN YunFei 1,2,GONG GuangHong 2 & HAN Liang 2 1 College of computer Science,Chongqing university,Chongqing 400044,china 2 school of Automation Science and Electrical engineering,Beijing university of Aeronautics and Astronautics,Beijing 100083,china 1. College of computer Science Chongqing University Chongqing 400044 China2. School of Automation Science and Electrical Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

For the large quantity of data,rules and models generated in the course of computer generated forces (CGFs) behavior modeling,the common analytical methods are statistical methods based on the tactical rules,tactical doctrine and empirical ***,from the viewpoint of data mining,we can find many of these analytical methods are also each-and-every different data mining *** this paper,we survey the data mining theory and techniques that have appeared in the course of CGF behavior modeling from the viewpoint of data ***,we redefine and reclassify these theories and techniques according to the research requirements of data mining (the knowledge structure of data mining).We aim to help the CGF investigators to learn the key points and the research methods of the data intelligent processing in the CGF behavior modeling,and thus we can provide the references for the colleagues who are engaged in the research and practice of the CGF behavior modeling by this *** also introduce our ongoing work on the CGF behavior modeling based on data mining.

关键词： CGF CGF behavior modeling data mining theory and techniques

Polylogarithms and multiple zeta values from free Rota-Baxter algebras

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Science china mathematics 2010年第9期53卷 2239-2258页

作者： GUO Li1,2 & ZHANG Bin3,1Center of Mathematical Sciences,Zhejiang university,Hangzhou 310027,china 2Department of mathematics and computer Science,Rutgers university,Newark,NJ 07102,USA 3Yangtze Center of mathematics,Sichuan university,chengdu 610064,china 1. Center of Mathematical Sciences Zhejiang University Hangzhou 310027 China2. Department of Mathematics and Computer Science Rutgers University Newark NJ 07102 USA3. Yangtze Center of Mathematics Sichuan University Chengdu 610064 China

We show that the shuffle algebras for polylogarithms and regularized MZVs in the sense of Ihara,Kaneko and Zagier are both free commutative nonunitary Rota-Baxter algebras with one *** apply these results to show that the full sets of shuffle relations of polylogarithms and regularized MZVs are derived by a single *** also take this approach to study the extended double shuffle relations of MZVs by comparing these shuffle relations with the quasi-shuffle relations of the regularized MZVs in our previous approach of MZVs by renormalization.

关键词： multiple zeta values polylogarithms Rota-Baxter algebras

NUMERICAL PREDICTION OF VORTEX FLOWIN HYDRAULIC TURBINE DRAFT TUBE FOR LES

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Journal of Hydrodynamics 2005年第4期17卷 448-454页

作者： LIU Xiao-bing ZENG Yong-zhong CAO Shu-you school of Energy and Environment Xihua University Chengdu 610039 China State Key Hydraulics Laboratory of High Speed Flows Sichuan University Chengdu 610065 China

The three-dimensional unsteady turbulent flow is studied numerically in the whole flow passage of hydraulic turbine, and vortex flow in the draft tube is predicted accurately in this paper. The numerical prediction is based on the Navier-Stokes equations and Large-Eddy Simulation （LES） model. The SIMPLE algorithm with the body fitted coordinate and tetrahedroid grid system is applied for the solution of the discretization governing equations.

关键词： vortex flow hydraulic turbine draft tube numerical prediction LES