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NONHOMOGENEOUS BOUNDARY VALUE PROBLEMS FOR THE KORTEWEG-DE VRIES EQUATION ON A BOUNDED DOMAIN

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Journal of Systems science & Complexity 2010年第3期23卷 499-526页

作者： Eugene F. KRAMER Bingyu ZHANG department of Mathematics Physics and Computer Science University of Cincinnati Raymond Walters College Cincinnati Ohio 45236 USA department of Mathematical sciences University of Cincinnati Cincinnati Ohio 45221 USA

This paper studies an initial-boundary-value problem (IBVP) of the Korteweg-de Vriesequation posed on a finite interval with general nonhomogeneous boundary *** thestrong Kato smoothing property of the associated linear problem,the IBVP is shown to be locallywell-posed in the space H^s(0,1) for any s≥0 via the contraction mapping principle.

关键词： KdV equation Korteweg-de Vries equation well-posed.

Routing Protocols for Transmitting Large Databases or Multi databases Systems

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Wuhan univer.ity Journal of Natural sciences 2001年第Z1期6卷 448-450页

作者： He Hong, Ma Shao han computer science department of Shandong univer.ity, Jinan 250100, China computer science department of Shandong univer.ity Jinan China

Most knowledgeable people agree that networking and routing technologies have been around about 25 years. Routing is simultaneously the most complicated function of a network and the most important. It is of the same kind that more than 70% of computer application fields are MIS applications. So the challenge in building and using a MIS in the network is developing the means to find, access, and communicate large databases or multi databases systems. Because general databases are not time continuous, in fact, they can not be streaming, so we can't obtain reliable and secure quality of service by deleting some unimportant datagrams in the databases transmission. In this article, we will discuss which kind of routing protocol is the best type for large databases or multi databases systems transmission in the networks.

关键词： network routing protocol databases transmission

A HYPERBOLIC SYSTEM OF CONSERVATION LAWS FOR FLUID FLOWS THROUGH COMPLIANT AXISYMMETRIC VESSELS

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Acta Mathematica Scientia 2010年第2期30卷 391-427页

作者： Gui-Qiang G.Chen School of Mathematical sciences,Fudan univer.ity,Shanghai 200433,China Mathematical Institute,univer.ity of Oxford,24-29 St Giles,Oxford,OX1 3LB,UK department of Mathematics,Northwestern univer.ity,Evanston,IL 60208-2730,usa Weihua Ruan department of Mathematics,computer science and Statistics,Purdue univer.ity Calumet,Hammond,IN 46323-2094,usa [a] School of Mathematical sciences Fudan University Shanghai 200433 China [b] Mathematical Institute University of Oxford 24-29 St Giles Oxford OX1 3LB UK [c] Department of Mathematics Northwestern University Evanston IL 60208-2730 USA [d] Department of Mathematics Computer Science Statistics Purdue University Calumet Hammond IN 46323-2094 USA

We are concerned with the derivation and analysis of one-dimensional hyperbolic systems of conservation laws modelling fluid flows such as the blood flow through compliant axisyminetric vessels. Early models derived are nonconservative and/or nonho- mogeneous with measure source terms, which are endowed with infinitely many Riemann solutions for some Riemann data. In this paper, we derive a one-dimensional hyperbolic system that is conservative and homogeneous. Moreover, there exists a unique global Riemann solution for the Riemann problem for two vessels with arbitrarily large Riemann data, under a natural stability entropy criterion. The Riemann solutions may consist of four waves for some cases. The system can also be written as a 3 × 3 system for which strict hyperbolicity fails and the standing waves can be regarded as the contact discontinuities corresponding to the second family with zero eigenvalue.

关键词： conservation laws hyperbolic system fluid flow blood flow vessel hyper-bolicity Riemann problem Riemann solution wave curve shock wave rarefaction wave standing wave stability

A polynomial algorithm for finding (g,f)-colorings orthogonal to stars in bipartite graphs

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science China Mathematics 2005年第3期48卷 322-332页

作者： LIU Guizhen & DENG Xiaotie department of Mathematics, Shandong univer.ity, Jinan 250100, China department of computer science, The City univer.ity of Hong Kong, Hong Kong, China 1. department of Mathematics Shandong University 250100 Jinan China 2. department of computer science The City University of Hong Kong Hong Kong China

Let G be a bipartite graph with vertex set V(G) and edge set E(G), and let g and f be two nonnegative integer-valued functions defined on V(G) such that g(x) ≤f(x)for every vertex x of V(G). A(g,f)-coloring of G is a generalized edge-coloring in which each color appears at each vertex x at least g(x) and at most f(x) times. In this paper a polynomial algorithm to find a(g, f)-coloring of a bipartite graph with some constraints using the minimum number of colors is given. Furthermore, we show that the results in this paper are best possible.

关键词： bipartite graph, (g, f)-coloring, (g, f)-factor, orthogonal coloring.

Secure, dependable and publicly verifiable distributed data storage in unattended wireless sensor networks

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science China(Information sciences) 2010年第5期53卷 964-979页

作者： REN Wei 1 , REN Yi 2 & ZHANG Hui 3 1 School of computer science, China univer.ity of Geosciences (Wuhan), Wuhan 430074, China 2 department of Information and Communication Technology, univer.ity of Agder (UiA), Norway 3 department of Electronics, Politecnico di Torino (POLITO), Italy 1. School of computer science China University of Geosciences (Wuhan) Wuhan 430074 China2. Department of Information and Communication Technology University of Agder (UiA) Kristiansand Norway3. Department of Electronics Politecnico di Torino (POLITO) Torino Italy

In unattended wireless sensor networks (UWSNs), sensed data are stored locally or at designated nodes and further accessed by authorized collectors on demand. This paradigm is motivated by certain scenarios where historical or digest data (e.g., average temperature in a day), instead of real-time data, are of interest. The data are not instantly forwarded to a central sink upon sensing, thereby saving communication energy for transmission. Such a paradigm can also improve data survivability by making use of distributed data storage in cheap flash memory on nodes. However, the security and dependability of such data storage are critical for the future data accessibility in UWSNs. To address this issue, we propose a secure and dependable distributed storage scheme for UWSNs. Our scheme takes advantages of both secret sharing and Reed-Solomon code, which can achieve computational security and maintain low communication overhead in terms of shortened data dispersing size. We also propose a general coding method to publicly verify data integrity in a distributed manner, with low communication and storage overhead, and without the need of holding original data. The extensive analysis justifies that our scheme can provide secure, dependable and publicly verifiable distributed data storage in UWSNs even in the presence of node compromise and Byzantine failure.

关键词： secure storage dependability data integrity wireless sensor networks wireless network security

CONVERGENCE RATES OF MARKOV CHAIN APPROXIMATION METHODS FOR CONTROLLED DIFFUSIONS WITH STOPPING

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Journal of Systems science & Complexity 2010年第3期23卷 600-621页

作者： Qingshuo SONG Gang George YIN department of Mathematics City University of Hong Kong 83 Tat Chee Avenue Kowloon Tong Hong Kong China department of Mathematics Wayne State University Detroit Michigan 48202 USA

This work is concerned with rates of convergence of numerical methods using Markov chainapproximation for controlled diffusions with stopping (the first exit time from a bounded region).In lieuof considering the associated finite difference schemes for Hamilton-Jacobi-Bellman (HJB) equations,a purely probabilistic approach is *** is an added difficulty due to the boundary condition,which requires the continuity of the first exit time with respect to the discrete *** prove theconvergence of the algorithm by Markov chain approximation method,a tangency problem might arise.A common approach uses certain conditions to avoid the tangency ***,by modifying thevalue function,it is demonstrated that the tangency problem will not arise in the sense of convergencein probability and in L^*** addition,controlled diffusions with a discount factor is also treated.

关键词： Controlled diffusion dynamic programming equation Markov chain approximation rate of convergence.

A NEW METHOD IN GROUNDWATER FLOW MODELING

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Journal of Hydrodynamics 2009年第2期21卷 245-254页

作者： MA Xiu-yuan LI Shu-guang ZHU Wei-shen School of Civil Engineering Shandong University Jinan 250061 China department of Civil and Environmental Engineering Michigan State University East Lansing Michigan 48834USA

One of the challenges in groundwater modeling is the prediction of hydraulic head related to local stress fluctuations with a regional scale model. Typical applications of numerical models require extensive field information for input data and for calibration If we can model the change directly, we may not have to know all the modeling parameters because sometimes the changes only depend on fewer parameters. In this article, we present an improved methodology for groundwater modeling related to local stress fluctuations using a perturbation approach. Our results demonstrate that this approach is capable of matching an exact solution for drawdown in both confined and unconfined aquifers. The results suggest that this perturbation method can provide an accurate representation of head in a large-scale hydrogeological system.

关键词： groundwater modeling local stress fluctuations perturbation method iteration scheme

An Automatic Testing System of Scheduling Strategies in Real-Time UNIX

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Journal of Systems Engineering and Electronics 2001年第2期12卷 59-62页

作者： Qin Xiao, Pang Liping & Han Zongfen department of computer science, Huazhong univer.ity of science and Technology, Wuhan 430074, P. R. China department of computer science Huazhong University of Science and Technology Wuhan 430074 P. R. China

This paper proposes a formal model of the automatic testing system for scheduling strategies in real-time UNIX and describes the algorithm of the key part of the system. The model of the system is an important technology of the automatization of software development. According to the model presented in the paper, many different kinds of automatic testing systems can be designed and developed easily. At the end of the paper, the prototype proves the feasibility of the model and design.

关键词： Algorithms Automatic testing Real time systems Scheduling Software prototyping

Design of Chinese-English Machine Translation System CEMT-Ⅱ

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哈尔滨工业大学学报 1990年第3期22卷 39-44页

作者： Zhou Ming Li Sheng Cheng Guangxi Hu Mingzeng (department of computer science)

This paper describes the design of CEMT-Ⅱ, an interactive Chinese-English machine translation system. Based on the CEMT-Ⅰsystem, CEMT-Ⅱwill be developed to have the ability to translate Chinese scientific documents into English. Now an user-friendly interface has been worked out to solve various complex ambiguities. The Chinese user need not know English well since all the questions and choices are expressed in Chinese.

关键词：汉英机器翻译系统 CEMT-Ⅱ 句型分析科技语言设计