网络计划编制系统中网络图的自动生成

本文从设计角度，系统地介绍了一个计算机网络计划编制系统中如何实现计算机辅助生成网络图和时间坐标网络图的方法与步骤。并阐述了资源优化的计算机实现。     

基于动态服务网络的铁路紧急输送计划编制模型和算法

根据特殊条件下铁路输送计划问题的动态性、多目标性、时效性等特点,采用时空网络构建铁路输送计划网络模型.并建立了基于动态路径的铁路输送计划编制数学模型.模型属于大规模的整数规划,以追求时间效益最大化和灾害损失最小化为目标.根据模型的特点,提出了松弛求解算法,借助LINGO求解工具求解松弛模型,通过逐步固定变量为整数值求得最优解.算例研究表明,算法可行有效.     

基于动态服务网络的铁路紧急输送计划编制模型和算法北大核心

根据特殊条件下铁路输送计划问题的动态性、多目标性、时效性等特点,采用时空网络构建铁路输送计划网络模型.并建立了基于动态路径的铁路输送计划编制数学模型.模型属于大规模的整数规划,以追求时间效益最大化和灾害损失最小化为目标.根据模型的特点,提出了松弛求解算法,借助LINGO求解工具求解松弛模型,通过逐步固定变量为整数值求得最优解.算例研究表明,算法可行有效.     

基于合作博弈的招生计划分配优化模型研究

招生计划编制是落实高等教育改革和调整人才结构的重要手段.针对招生计划编制过程中招生计划分配的合理性和有效性难题,提出一种招生计划分配的优化模型.首先,建立招生计划分配的高校综合评价指标体系,并采用相对比值法评价该体系,得到的相对比值反映高校综合办学水平.其次,将相对比值这个评价结果作为招生计划分配规则的影响因子,将招生计划分配归结为带影响因子的破产问题,采用有限制等损规则分配招生计划.实例分析说明,文章的优化模型具有良好的优越性和可操作性.研究结果可为省级教育行政部门的招生计划编制工作提供指导依据.     

淠史杭灌区管理信息系统的网络规划、设计与建设

随着信息技术的迅速发展,信息处理的方式正逐步由手工转向计算机,灌区管理工作对信息传输的可靠性和速度也提出了更高的要求,建设高效、可靠的以计算机网络为支持的灌区管理信息系统已成为发展的必要需求。本文介绍了淠史杭灌区管理信息系统计算机网络的总体规划、设计与建设情况     

绘制统筹网络图的一个标号算法及应用

本文给出了一个绘制统筹网络图的有效算法，称之为标号算法．利用标号算法可使计算机在只接收到各工序间紧前紧后关系的数据后，便可生成网络优化中必需的网络图形．利用该算法我们还建立了网络优化计算机辅助设计系统，该方法和计算机辅助设计系统，目前已在山东省兴隆庄煤矿井下的拆除和安装工程中得到了具体应用，收到了良好的效果．     

大型军工企业投入产出分析

本项目结合大型军工机械企业的特点和现行管理体制特点,采用“纯部门”分类,并以实际净消耗量作为投入量,是一种新的尝试。与传统计划编制方法比较,编制年增产节约效益为201万元。     

基于粒子群算法的大型网络计划费用优化

大型网络计划费用优化对科学有效地进行工程项目进度管理具有重要意义,但大型网络计划费用优化随工作个数增加而约束方程和计算量骤增,成为数学和计算机科学领域至今未解决的难题.借助建立评价函数、设计进化方程、设计网络计划时间参数的计算机算法等基础工作,选择工作持续时间作为粒子空间坐标并设置可行解范围,用蒙特卡洛方法和限制条件优化初始粒子群,用二维动态数组解决大型网络计划粒子群算法优化运行image超限问题,成功求解有61个工作的大型网络计划费用优化算例.因此,经过特定设计的粒子群算法是微机和有限的计算时间条件下求解大型网络计划费用优化问题的一个有效方法.     

中药配伍系统(CSCMM)的复杂网络拓扑特征分析

通过构建表征中药配伍系统(CSCMM)的复杂网络,按照整体论、系统论的思想,运用复杂网络的理论,借助整体网络的分析技术和计算机可视化算法对CSCMM进行了宏观综合的量化分析和定性阐释,揭示了该网络诸如小世界和近似无标度等网络拓扑特征,以期为中药配伍的现代化研究提供一定的思考和启发.     

多类顾客多服务台队列网络的高负荷极限定理

多类顾客多服务台队列网络广泛地应用到计算机网络、通讯网络和交通网络 .由于系统的复杂性 ,其数量指标的精确解很难求出 .为了寻求逼近解 ,本文用概率测度弱收敛理论对进行了研究 ,在高负荷的条件下 ,我们获得了网输入过程、闲时过程和负荷过程的极限定理 .     

New standards for the solution of geometric calculation problems by using computers

The availability of computers and of software for the geometric tasks of construction, measurement and calculation, as well as the availability of software for numerical and symbolic computation induce new methods for the solution of geometric calculation problems: computer-aided graphical, numerical and algebraic methods of solution. These computer-aided solutions are explained in relation to suitably chosen tools (Mathematica and Cabri Géomètre) and traditional examples.     

A review of methods for computer-aided reconstruction of solid models of objects by their orthographic views

The paper contains a review of methods for computer-aided reconstruction of three-dimensional solid models of objects by their orthographic views. This problem arises when passing from engineering 2D-drawings to spatial models of objects in systems of three-dimensional solid modeling. In spite that there exists a large variety of such systems, none of them provides a computer-aided solution of this problem. This is due to the fact that the existing methods for solution are imperfect and require further elaboration. In this paper, we review the existing approaches and compare their application domains.     

Numerical and physical modeling of the dynamics of the Lorenz system

This paper describes a modification of the method of power series for the construction of approximate solutions of the Lorenz system. The results of a computer-aided simulation are presented. Also, physical modeling of the dynamics of the Lorenz system for processes occurring in an electric circuit is considered.     

Computerunterstütztes Lösen offener raumgeometrischer Aufgaben

Considering the fact that solid geometry has been a neglected subject in mathematics teaching at lower and middle secondary level, there has been almost no chance to develop a “culture” of open, solid geometry problem solving. Suitable software tools for spatial representations, construction and calculation tasks can support the students in developing and solving open problems in solid geometry designed in line with the content of the conventional geometry curriculum. The article presents problems of this kind and explains the computer-aided problem solving processes. Furthermore, initial results of evaluations of practical lessons including computerized treatment of selected open problems are reported. Finally, the general significance is discussed of introducing the computer as a tool in spatial geometry teaching as well as the basic problems involved in an evaluation of computer-assisted teaching in this context, and further development of computer-aided, open problem solving in spatial geometry.     

Multi-objective modeling for engineering applications:DIDASN++ system

Modeling and simulation of various physical, technical, environmental or socioeconomic processes is often a preliminary step for using the resulting models in computer-aided design or decision support. In engineering computer-aided design, the decisions of the designer might be supported by multicriteria optimization - which in this case should not be considered as a tool for supporting the final choice of the design, but much more as a tool for helping in a flexible analysis of various design options or even various modeling and simulation options. The paper shows how multicriteria optimization techniques can be used for multi-objective analysis of a model from the beginning stages of model construction. With the advancement of computing technology and the methodology of decision support, it is now possible to revise this way basic approaches to modeling and simulation. Various formats of defining nonlinear and time-discrete models are discussed together with related problems of inverse and softly constrained multi-objective simulation. Algebraic differentiation and sensitivity analysis, fuzzy set representation of modeler preferences are also useful techniques of multi-objective modeling. Such techniques are illustrated by engineering applications of a software package DIDASN++ in mechanics and automatic control.     

Computer-aided design of synchronous generators with comb rotors

A mathematical model of a synchronous generator with comb rotor is implemented in a computer-aided design (CAD) package. The model integrates the differential equations characteristic of an electric machine; tabled data and empirical coefficients; and geometric, electromagnetic, and economic parameters of machine design. The complexity of the model requires that the solution procedure adopt a naive random search methodology, and an expert system is integrated within the package. The expert system is used mainly for guidance, and the priority of initial parameter values is delegated to the designer. An illustrative example is described to demonstrate the methodology of the computer-aided design procedure.     

New protocols for solving geometric calculation problems incorporating dynamic geometry and computer algebra software

The ready availability today of both software for geometric construction, measurement and calculation, and software for numerical calculation and symbolic analysis, when taken together allow new approaches to the solution of geometric problems. These computer-aided graphical, numerical and algebraic methods of solution are illustrated and discussed by means of examples, using an appropriate choice of software tools, and provide an indication of the possible future when fully integrated software is available.     

A Unified Treatment of Invariance for Curve- and Surface-defining Algorithms

The behaviour of plane-curve algorithms under transformationis studied systematically with a view to the construction ofnew algorithms, for computer-aided design applications, withany required invariance characteristics built in. The resultsobtained may also be used for the determination of invarianceproperties of algorithms in current use and for evaluating therelative merits of alternative parameterizations of a givenalgorithm. A number of common algorithms of practical importanceare considered and some generalizations are discussed includingthe extension to surfaces.     

On weakly APN functions and 4-bit S-Boxes

S-Boxes are important security components of block ciphers. We provide theoretical results on necessary or sufficient criteria for an (invertible) 4-bit S-Box to be weakly APN. Thanks to a classification of 4-bit invertible S-Boxes achieved independently by De Cannière and Leander–Poschmann, we can strengthen our results with a computer-aided proof. We also propose a class of 4-bit S-Boxes which are very strong from a security point of view.