ECC密码体制结合图像隐藏的安全传输

图像隐藏技术常与RSA密码体制结合,然而RSA要增加其破译强度必须增加密钥长度,同时图像隐藏信息量却有一定的限制,这就造成密钥存储空间增长与有限隐藏空间的矛盾。论文提出将椭圆曲线密码体制与图像隐藏结合, 利用ECC在相同安全强度下密钥长度短的特点在一定程度上解决了这一矛盾,同时达到安全性和隐蔽性的结合。     

电子政务中基于角色的交叉集散授权策略

为了能够准确、有效、安全地为参与电子政务的部门或人授权,针对权限交叉带来的管理混乱现象,论文构建了基于角色的扩展授权模型(ExtendedRole-BasedAuthorizationModel,简称ERBAM),使用向上查询授权人的集中与分散授权方法,提出了基于角色的交叉集散授权策略,有效解决了电子政务中权限有交叉的授权管理问题。该方法已经成功应用于某电子政务系统。     

Parallelization of a Two-Phase Metaheuristic for Routing Problems with Time Windows

This paper describes the parallelization of a two-phase metaheuristic for the vehicle routing problem with time windows and a central depot (VRPTW). The underlying objective function combines the minimization of the number of vehicles in the first search phase of the metaheuristic with the minimization of the total travel distance in the second search phase. The parallelization of the metaheuristic follows a type 3 parallelization strategy (cf. Crainic and Toulouse (2001). In F. Glover and G. Kochenberger (eds.). State-of-the-Art Handbook in Metaheuristics. Norwell, MA: Kluwer Academic Publishers), i.e. several concurrent searches of the solution space are carried out with a differently configured metaheuristic. The concurrently executed processes cooperate through the exchange of solutions. The parallelized two-phase metaheuristic was subjected to a comparative test on the basis of 358 problems from the literature with sizes varying from 100 to 1000 customers. The derived results seem to justify the proposed parallelization concept.     

A relaxed primal-dual path-following algorithm for linear programming

In this paper, we provide an easily satisfied relaxation condition for the primaldual interior path-following algorithm to solve linear programming problems. It is shown that the relaxed algorithm preserves the property of polynomial-time convergence. The computational results obtained by implementing two versions of the relaxed algorithm with slight modifications clearly demonstrate the potential in reducing computational efforts.Partially supported by the North Carolina Supercomputing Center, the 1993 Cray Research Award, and a National Science Council Research Grant of the Republic of China.     

On the entropic perturbation and exponential penalty methods for linear programming

This note points out that the recently proposed exponential penalty approach to linear programming is identical to the well-known entropic perturbation approach. The primal and dual trajectories provided by these two approaches are shown to be equivalent.The work of the first author was supported partially by the North Carolina Supercomputing Center and 1995 Cray Research Grant.     

Integrated VP-Based Control Strategies for ATM Survivable Networks

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Hedging of the European option in discrete time under proportional transaction costs

In the paper hedging of the European option in a discrete time financial market with proportional transaction costs is studied. It is shown that for a certain class of options the set of portfolios which allow to hedge an option in a discrete time model with a bounded set of possible changes in a stock price is the same as the set of such portfolios, under assumption that the stock price evolution is given by a suitable CRR model.     

On existence of undominated pure strategy Nash equilibria in anonymous nonatomic games: a generalization

In this paper, we generalize the exitence result for pure strategy Nash equilibria in anonymous nonatomic games. By working directly on integrals of pure strategies, we also generalize, for the same class of games, the existence result for undominated pure strategy Nash equilibria even though, in general, the set of pure strategy Nash equilibria may fail to be weakly compact. Received August 2001     

基于分级和空间相关性结合的H.264-P帧模式决定快速算法

为了降低H．264中模式决定过程的复杂度，提出了一种快速算法。该方法首先检测当前宏块的相邻宏块．当相邻宏块都可用时，使用基于空间相关性的模式决定方法；当相邻宏块并不都为可用时，使用分级模式决定策略．采用以上方法．将空间相关性与分级策略有效地结合起来，减少了计算量，并且对图像质量以及码率没有明显的影响．实验表明．这种新算法平均可以节省的计算时间约为41．7％，同时PSNR下降了约0．12dB，具有一定的现实意义。     

当前中国的LCD产业专利策略分析

回顾并分析了夏普与东元之间发生专利纠纷的背景、过程及解决的策略,结合LCD产业的专利分布及技术壁垒,提出我国LCD产业的专利策略。