高校校园网PKI系统模型研究与分析

文章在分析高校校园网的基础上，为了保证网络安全所包含的数据真实性、保密性、完整性、不可否认性，提出了两层CA多RA结构PKI系统模型。     

加油卡网络安全设计

在分析中石化加油IC卡网络的基础上,为保证网络安全所包含的数据真实性、保密性、完整性、不可否认性,提出了基于Windows．NET Server的单CA多RA的PKI系统。     

高校校园网PKI的设计

文章在分析高校校园网的基础上，为了保证网络安全所包含的数据真实性、保密性、完整性、不可否认性，提出了基于Windows．NET Server的单CA多RA的PKI系统。     

PKI/CA在宁夏的应用和面临的问题

安全问题是人们在开展网上业务时所关心的最主要的问题．如何保证网上业务的公正性和安全性．保证业务双方身份的真实性．保证传递信息的完整性以及业务的不可抵赖性？国际上提出了基于公钥基础结构(PKI——Public Key Infrastructure)的PKI／CA数字证书解决方案．现已被普遍采用。     

DNS安全研究

作为互联网关键基础设旋的域名系统（DNS）其安全性正面,临严峻考验。协议设计脆弱性导致数据信息真实性和完整性得不到保证,该文对域名系统进行分析,并讨论了解决办法。     

基于集成技术的一种安全交易模型研究

通过对数字签名机制的研究，发现基于数字签名的网络安全交易模型存在着明显的安全缺陷，即数据的完整性和真实性无法得到保证。由于脆弱水印技术在对多媒体信息的完整性及真实性认证方面有其独到之处，于是提出了一种结合脆弱水印、信息隐藏和加密技术的网络安全交易模型。分析表明，模型实现了身份认证和内容的完整性认证，同时能防止发送者的抵赖和接收者的非法伪造，实现了交易双方的信息在网上安全隐蔽的交易。     

一种基于可信计算平台的无线传感器网络标识密钥更新方法

针对无线传感器网络使用标识密码的密钥更新问题,设计了一种以可信计算平台为密钥生成中心,利用单向函数构造随机数池的高效密钥更新方案,使得传感器节点既能对密钥更新消息进行验证,又不至于引起过多的网络通信。为保证通信密钥的安全性,使用可信计算平台作为密钥生成中心,保证了密钥源头的安全。密钥更新时,利用可信计算平台的特性对其平台配置情况进行验证,来判断其所发出的消息和密钥的真实性与完整性。利用单向函数产生随机数池,一方面使得传感器节点可以验证消息的真实性,另一方面可以抵抗重放攻击。     

银行信贷登记咨询系统的安全解决方案

为了满足银行信贷登记咨询系统数据上传、下载、查询、产生报表等对数据传输的安全要求，通过采用中国金融认证中心的数字证书，保证了信息传输的机密性、真实性、完整性和不可否认性。     

综论公钥基础设施

随着Internet的快速发展与普及,基于Internet应用的安全问题日益突出,如电子商务安全,电子邮件安全,数据库管理系统安全等。网络信息安全主要解决的问题包括传输数据的真实性,完整性,机密性和不可抵赖性。真实性就是保证数据接收者能够验证消息发送者的真实身份,以防假冒;完整性是指消息接收者能够判断接收到的数据在传输过程中是否被非法篡改,确信收到的是完整的数据;机密性是保证敏感数据通过网络传输时不会泄密;不可抵赖性就是防止消息发送者对其发送过的内容     

新形势下有关信息安全系统改革的探讨

进入二十一世纪以来随着全球政治、经济形势的不断变革,领域内各行各业均受到不同程度的冲击与影响,这就使信息这一新兴战略资源显得格外重要,信息安全(Information safety)主要包括保证信息的保密性、真实性、完整性、未授权拷贝和所寄生系统的安全性。本文将分析新形势下信息安全系统的需求趋势等展开调查确实并在此基础上提升一些建设性的意见。     

一种新的求解MMKP问题的ACO&PR算法

针对多选择多维背包问题(MMKP)的特点,设计一种新型混合算法(ACO＆PR).该算法将线路重连算法(PR)嵌入蚁群算法(ACO),在搜索过程中既考虑解的质量,又考虑解的分散性.线路重连算法在重连过程中,向导解的属性逐步引入起始解属性中,可快速获得该线路上的最优解.实验结果表明,该算法优于其他现有较好的方法,获得了较好的结果.     

一种新的项目调度解表示方法

基于解集合的准启发式方法是解决资源约束下项目调度问题的有效方法,解的表示形式一直是这种方法的一个重要研究问题。只有充分利用解的形式和目标函数之间的联系,才可能达到在少数枚举下得到尽可能好的解。详细分析了解空间性质,提出了用额外关系表示一个可行解的方法,给出了这种表示方法的理论依据。并介绍了用该方法产生邻域的方法。     

模糊图上合作对策的平均树解

针对模糊图上的平均树解进行研究.在无向模糊图中,参与者本身与参与者之间有不同的参与水平,利用Choquet积分函数对模糊图进行划分,定义模糊平均树解,并证明它是满足模糊分支有效性和cg分支公平性的唯一解,以及满足模糊分支有效性和模糊分支公平性的唯一解.此外,当无圈模糊图合作对策满足超可加性时,证明模糊平均树解是核中的元素,即该解是稳定的.利用Choquet积分函数和深度搜索算法(DFS)将无圈图上的模糊平均树解推广到任意图上,拓展了任意图上模糊平均树解的表达形式.最后,通过一个供应链算例计算并分析模糊图上合作对策的平均树解.     

Eigenfactor solution of the matrix Riccati equation--A continuous square root algorithm

This paper introduces a new algorithm for solving the matrix Riccati equation. Differential equations for the eigenvalues and eigenvectors of the solution matrix are developed in which their derivatives are expressed in terms of the eigenvalues and eigenvectors themselves and not as functions of the solution matrix. The solution of these equations yields, then, the time behavior of the eigenvalues and eigenvectors of the solution matrix. A reconstruction of the matrix itself at any desired time is immediately obtained through a trivial similarity transformation. This algorithm serves two purposes. First, being a square root solution, it entails all the advantages of square root algorithms such as nonnegative definiteness and accuracy. Secondly, it furnishes the eigenvalues and eigenvectors of the solution matrix continuously without resorting to the complicated route of solving the equation directly and then decomposing the solution matrix into its eigenvalues and eigenvectors. The algorithm which handles cases of distinct as well as multiple eigenvalues is tested on several examples. Through these examples it is seen that the algorithm is indeed more accurate than the ordinary one. Moreover, it is seen that the algorithm works in cases where the ordinary algorithm fails and even in cases where the closed-form solution cannot be computed as a result of numerical difficulties.     

一种基于多模式加密算法的文件保护方案*

结合对称密码算法中的DES、IDEA、AES和单向散列算法中的MD5、SHA-1、SHA-256等算法,提出了一种在同一文件内部采用多模式加密的方案,该方案比传统的单一模式加密的方案能更好地保证数据的完整性和安全性.详细描述了该方案的算法实现,通过试验验证了其实用性,同时分析了该方案的优点和不足.     

A new fundamental solution for differential Riccati equations arising in control

The matrix differential Riccati equation (DRE) is ubiquitous in control and systems theory. The presence of the quadratic term implies that a simple linear-systems fundamental solution does not exist. Of course it is well-known that the Bernoulli substitution may be applied to obtain a linear system of doubled size. Here, however, tools from max-plus analysis and semiconvex duality are brought to bear on the DRE. We consider the DRE as a finite-dimensional solution to a deterministic linear/quadratic control problem. Taking the semiconvex dual of the associated semigroup, one obtains the solution operator as a max-plus integral operator with quadratic kernel. The kernel is equivalently represented as a matrix. Using the semigroup property of the dual operator, one obtains a matrix operation whereby the kernel matrix propagates as a semigroup. The propagation forward is through some simple matrix operations. This time-indexed family of matrices forms a new fundamental solution for the DRE. Solution for any initial condition is obtained by a few matrix operations on the fundamental solution and the initial condition. In analogy with standard-algebra linear systems, the fundamental solution can be viewed as an exponential form over a certain idempotent semiring. This fundamental solution has a particularly nice control interpretation, and might lead to improved DRE solution speeds.     

An augmented Lagrangian optimization method for contact analysis problems, 2: numerical evaluation

The ALM2 solution procedure is evaluated by solving two simple contact analysis problems for different friction conditions. These example problems are devised to have closed form solutions. This way there is no uncertainty about the target solution for evaluation of the proposed algorithm as well as existing algorithms. The numerical results with ALM2 are compared with the analytical solutions as well as with the penalty, Lagrange multiplier and existing augmented Lagrangian methods. All the algorithms are analysed for stick and slip friction conditions. The example problems are used to show clearly the dependence of the existing solution methods on the number of load steps and penalty values. It is concluded that convergence of incremental solution schemes employed in these methods does not guarantee accuracy of the contact solution even with the use of solution enhancement schemes such as automatic load stepping and contact load prediction. The example problems are also used to demonstrate solution independence of the proposed ALM2 procedure from penalty values, and from the number of load steps. The proposed formulation for calculation of frictional forces and the ALM solution algorithm have worked quite well for the example problems. However, the algorithm needs to be developed and evaluated for more complex contact analysis problems.     

制造企业信息集成系统的研究

提出制造企业信息集成系统的模型和组成方案,并分析企业资源计划系统、工程设计系统、制造执行系统、车间底层控制和信息集成支撑系统等制造企业信息集成系统的组成模块的功能。     

Recursive approximate solution to time-varying matrix differential Riccati equation: linear and nonlinear systems

An approximate solution is proposed for linear-time-varying (LTV) systems based on Taylor series expansion in a recursive manner. The intention is to present a fast numerical solution with reduced sampling time in computation. The proposed procedure is implemented on finite-horizon linear and nonlinear optimal control problem. Backward integration (BI) is a well known method to give a solution to finite-horizon optimal control problem. The BI performs a two-round solution: first one elicits an optimal gain and the second one completes the answer. It is very important to finish the backward solution promptly lest in practical work, system should not wait for any action. The proposed recursive solution was applied for mathematical examples as well as a manipulator as a representative of complex nonlinear systems, since path planning is a critical subject solved by optimal control in robotics.     

Optimal data placement on disks: a comprehensive solution fordifferent technologies

The problem of optimally placing data on disks (ODP) to maximize disk-access performance has long been recognized as important. Solutions to this problem have been reported for some widely available disk technologies, such as magnetic CAV and optical CLV disks. However, important new technologies such as multizoned magnetic disks, have been recently introduced. For such technologies no formal solution to the ODP problem has been reported. In this paper, we first identify the fundamental characteristics of disk-device technologies which influence the solution to the ODP problem. We develop a comprehensive solution to the problem that covers all currently available disk technologies. We show how our comprehensive solution can be reduced to the solutions for existing disk technologies, contributing thus a solution to the ODP problem for multizoned disks. Our analytical solution has been validated through simulations and through its reduction to the known solutions for particular disks. Finally, we study how the solution for multizoned disks is affected by the disk and data characteristics