数据仓库在异构数据库集成中的应用

信息系统存在大量的异构数据库,如何集成异构数据库、解决信息孤岛现象是一个难题。本文给出了异构数据库的集成方案,提出了从异构数据库抽取和转换数据的新方法,提出了ODBC用于数据抽取过程的思路,提出了数据转换规则集的概念并用于数据转换过程中。利用数据仓库技术来集成异构数据库是一个理想的解决方案。     

异构数据库数据集成的研究与实现

由于企业间数据的交互和共享越来越广泛，迫切需要对异构数据库数据进行集成。根据异构数据集成的需要．提出了利用XML技术集成异构数据库数据源的一个框架。框架核心部分由3层结构组成，综合管理层负责数据抽取和数据交互，XML数据库层负责数据预处理和查询，装配管理层根据需要过滤和组装数据，最终得到需要的数据。用Java编程实现了一个原型系统，对Oracle和SOL server实际数据源做了数据集成测试。实验结果证明该架构是一个较优的解决方案。     

利用数据仓库技术解决异构数据库的集成问题

企业信息系统存在大量的异构数据库，如何集成异构数据库、解决信息孤岛现象是我们面临的问题。利用数据仓库技术来集成异构数据库是一个理想的解决方案。本文给出了异构数据库的集成方案，提出了从异构数据库抽取和转换数据的新方法，提出了ODBC用于数据抽取过程的思路，提出了数据转换规则集的概念并用于数据抽取过程中。数据仓库的建立不仅实现了企业信息系统中信息的集成，更重要的是为企业决策提供了信息源。     

异构数据库数据集成的研究与实现

由于企业间数据的交互和共享越来越广泛,迫切需要对异构数据库数据进行集成。根据异构数据集成的需要,提出了利用XML技术集成异构数据库数据源的一个框架。框架核心部分由3层结构组成,综合管理层负责数据抽取和数据交互,XML数据库层负责数据预处理和查询,装配管理层根据需要过滤和组装数据,最终得到需要的数据。用Java编程实现了一个原型系统,对Oracle和SQL server实际数据源做了数据集成测试。实验结果证明该架构是一个较优的解决方案。     

多源异构数据融合与高性能图数据库查询引擎设计

文章针对多源异构数据整合及高性能图数据库查询引擎设计问题,提出创新技术解决方案。通过深度融合实现数据整合与高效存储,并引入先进图数据库技术,以快速响应复杂查询请求。实验证明,该系统在多源异构数据融合和图数据库查询方面具有明显的性能优势,为实际应用提供了可行解决方案。     

Power Builder环境下异构数据集成实现技术

针对数据库应用系统中对异构数据的操作和集成问题,提出了在Power Builder环境下实现对异构数据库集成的三种解决方案:利用动态配置数据源实现数据集成;利用数据管道实现数据集成和利用数据窗口技术实现数据集成,并详细阐述了三种方案的实现过程.     

基于XML与.Net Remoting的分布式异构数据转换

本文主要介绍.Net框架体系下,.remoting分布式应用解决方案的体系结构和具体实施.以及在异构数据库转化过程中使用的中介XML(eXtensible Markup Lanuage可扩展标签语言).主要是以.Net Remoting构建分布式平台,利用XML作为异构数据库转化的中介,实现分布式异构数据的转换.     

异构数据库间的数据转换

异构数据库系统间进行数据转换是当今开发人员经常遇到的问题，本文基于实际经验，简单论述了不同数据库管理系统间进行数据转换的不同解决方案。     

采用数据降维技术实现网络异构数据库分级数据共享

各主题数据库结构的复杂性,以及共享数据指标变量之间广泛的相关性,是异构数据库实现共享的重要障碍。目前的许多研究是针对异构数据库结构复杂问题,提出实现一致性访问的策略,但这些解决方案无法使系统达到良好的可扩展性。文中提出了一种新的解决方案,即发掘各主题数据库的结构共性,通过数据降维降低数据库结构上的复杂性,以实现库之间方便灵活的数据共享,从而达到较好的可扩展性。     

基于PowerBuilder数据管道的异构数据源的解决方案

首先简单分析了异构数据库的概念及其在企业中存在的原因和对企业产生的影响，并列举了一些异构数据源的解决方案，然后主要介绍了利用数据管道的转换方法。     

用组合优化的方法进行兵力分配

科学分配兵力在现代战争中是一个重要问题 ,用组合优化的方法进行兵力分配 ,并通过建立数学模型、模型求解 (包括可行解分组、组合解优化、求解问题的最优解 )来完成 ,最后得出兵力分配的最优解     

Solving Non-Linear Models with Saddle-Path Instabilities

Economic models derived from optimizing behavior are typically characterized by the properties of non-linearity and saddle-path instability. The typical solution method involves deriving the stable arm of the saddle-path and calculating suitable “jumps” to bring the path of endogenous variables onto this stable arm. The solution for the stable arm can be determined using a range of different approaches. In this paper we examine the extent to which the success of these alternative approaches can be evaluated. Any method of evaluation will be dependent upon the amount of information that is known about a particular model solution. For some deterministic models the only information known with certainty about the path of the model solution are values taken by steady-state solutions; the rest of the path must be approximated in some way based on numerical solutions derived from non-linear ordinary differential equations. In some special cases it is possible to derive a closed-form solution of the entire path. As an example of a model with a closed-form solution, we consider a simple linear model with two stable complex-valued eigenvalues and one unstable real-valued eigenvalue. The model is then employed as a benchmark to compare the properties of model solutions derived using two well-known solution algorithms. Because the model has complex-valued eigenvalues it will have cyclic dynamics and thus problems encountered in solving these dynamics will likely coincide with some of the problems that solution algorithms have in solving non-linear models. Since the entire solution path of the model is known, it is possible to derive deeper insights into the factors that are likely to ensure the success or failure of different solution approaches than would be the case if less information about the solution path was available.An earlier version of this paper was presented to the Ninth International Conference on Computing in Economics and Finance organized by the Society of Computational Economics, University of Washington at Seattle, July 11–13, 2003. Earlier versions of this paper have also been presented at seminars and workshops at the University of Oxford, at the University of Canterbury at Christchurch, and at the University of Melbourne. JEL Classifications: C63, E17     

Path following around corank-2 bifurcation pints of a semi-linear elliptic problem with symmetry

Bifurcating solution branches and their numerical approximations of a semi-linear elliptic problem are considered at corank-2 bifurcaton points. Utilization of basic group concepts allows a classification of the solution curves with their symmetries, and in turn, leads to reductions of singularity of the problem at bifurcation points and computational work in path following of solution branches.     

Initialisation of the adaptive Huber method for solving the first kind Abel integral equation

In the previous work of this author (Bieniasz in Computing 83:25–39, 2008) an adaptive numerical method for solving the first kind Abel integral equation was described. It was assumed that the starting value of the solution was known and equal zero. This is a frequent situation in some applications of the Abel equation (for example in electrochemistry), but in general the starting solution value is unknown and non-zero. The presently described extension of the method allows one to automatically determine both the starting solution value and the estimate of its discretisation error. This enables an adaptive adjustment of the first integration step, to achieve a pre-defined accuracy of the starting solution. The procedure works most satisfactorily in cases when the solution possesses all, or at least several of the lowest, derivatives at the initial value of the independent variable. Otherwise, a discrepancy between the true and estimated errors of the starting solution value may occur. In such cases one may either start integration with as small step as possible, or use a smaller error tolerance at the first step.      

基于TrueFFS的VxWorks映像在线升级设计与实现

针对嵌入式系统传统升级方法的不足,提出一种基于TrueFFS的嵌入式系统在线升级解决方案,实现了不需仿真器而直接通过网络在线升级VxWorks映像的功能。首先描述该方案的总体框架和工作原理;接着讨论实现该方案所要解决的关键技术;最后通过实例介绍该方案的技术实现过程。目前该方案已成功应用在项目中并取得满意的效果。     

虚拟机技术在计算机教学中的应用

针对目前计算机实践教学中存在的问题,提出了一种虚拟机技术的解决方法,该方法挖掘了现有设备的潜力,并能够增加学生的实践动手机会。     

虚拟机技术在计算机教学中的应用

针对目前计算机实践教学中存在的问题,提出了一种虚拟机技术的解决方法,该方法挖掘了现有设备的潜力,并能够增加学生的实践动手机会.     

Analysis of systems of singular ordinary differential equations

Systems of ordinary differential equations with a small parameter at the derivative and specific features of the construction of their periodic solution are considered. Sufficient conditions of existence and uniqueness of the periodic solution are presented. An iterative procedure of construction of the steady-state solution of a system of differential equations with a small parameter at the derivative is proposed. This procedure is reduced to the solution of a system of nonlinear algebraic equations and does not involve the integration of the system of differential equations. Problems of numerical calculation of the solution are considered based on the procedure proposed. Some sources of its divergence are found, and the sufficient conditions of its convergence are obtained. The results of numerical experiments are presented and compared with theoretical ones. Translated from Kibemetika i Sistemnyi Analiz, No. 5, pp. 103–110, September–October, 1999.     

On Existence and Uniqueness Verification for Non-Smooth Functions

Given an approximate solution to a nonlinear system of equations at which the Jacobi matrix is nonsingular, and given that the Jacobi matrix is continuous in a region about this approximate solution, a small box can be constructed about the approximate solution in which interval Newton methods can verify existence and uniqueness of an actual solution. Recently, we have shown how to verify existence and uniqueness, up to multiplicity, for solutions at which the Jacobi matrix is singular. We do this by efficient computation of the topological index over a small box containing the approximate solution. Since the topological index is defined and computable when the Jacobi matrix is not even defined at the solution, one may speculate that efficient algorithms can be devised for verification in this case, too. In this note, however, we discuss, through examples, key techniques underlying our simplification of the calculations that cannot necessarily be used when the function is non-smooth. We also present those parts of the theory that are valid in the non-smooth case, and suggest when degree computations involving non-smooth functions may be practical.As a bonus, the examples lead to additional understanding of previously published work on verification involving the topological degree.     

融合动态层次聚类和邻域区间重组的蚁群算法

针对蚁群算法搜索速度过慢以及解质量不足等问题,提出一种融合动态层次聚类和邻域区间重组的蚁群算法。在初始阶段,调整层次聚类阈值并按照类间距离最小合并的原则迭代至目标簇集,根据预合并系数进行簇间合并,通过蚁群系统得到小类路径并断开重组以加快算法整体收敛速度;接着使用蚁群系统对解空间进行优化,同时并行处理簇集与簇集邻域区间扩散重组,增加解的多样性,进一步固定迭代次数进行比较,若邻域区间重组解质量优于当前优化解则进行推荐处理,提高解的精度;当算法停滞时,引入调整因子降低各路径信息素之间差异以增强蚂蚁搜索能力,有助于算法跳出局部最优。实验结果表明,在面对大规模问题时,算法的精度在3%左右,该方法相比传统方法可以有效提高解的精度和收敛速度。