汽车销售“一条龙”服务的排队系统

本文以汽车销售业务为例,首次研究“一条龙”服务的排队系统。利用随机服务理论给出了该系统的各项运行指标。     

基于.Net的工厂方法模式研究与应用

设计模式简单方便地复用成功的模式和体系结构,使新系统开发者更加容易理解其设计思路。设计模式中的工厂方法模式为系统结构提供了非常灵活强大的动态扩展机制,本文阐述了工厂方法模式的体系结构以及工厂方法模式在软件开发中的具体应用。     

朴素的认知教学法在Web项目实战课程中的应用

本文提出了朴素的认知教学法,并将该方法应用于《Web项目实战》课程中。文中介绍了朴素的认知教学法的特点和主要教学流程,阐述了其在《Web项目实战》课程中的具体教学应用,总结了教学体会。     

Counting the different efficient paths for transportation networks and its applications

This paper deals with an interesting problem about how to efficiently compute the number of different efficient paths between an origin‐destination pair for a transportation network because these efficient paths are the possible paths used by drivers to some extent. Based on a novel triangle operation derived, it first presents a polynomial‐time combinatorial algorithm that can obtain the number of different simple paths between any two nodes for an acyclic network as well as the total travel cost of these paths. This paper proceeds to develop a combinatorial algorithm with polynomial‐time complexity for both counting the different efficient paths between an origin‐destination pair and calculating the total travel cost of these paths. As for applications, this paper shows that the preceding two algorithms can yield the lower and upper bounds for the number of different simple paths between an origin‐destination pair, while it has already be recognized that a polynomial‐time algorithm getting such a number does not exist for a general network. Furthermore, the latter algorithm can be applied for developing a heuristic method for the traffic counting location problem arising from the origin‐destination matrix estimation problems.     

基于 PEEC 理论的线缆建模方法

随着舰船上设备的增多,用于设备间通信的连接线缆的相互耦合越来越不可忽视。部分元等效电路方法（PEEC）作为一种场路结合的方法,通过场的方法提取等效电路参数,形成等效电路模型,进而进行相应的电路仿真计算。将 PEEC 方法应用于线缆建模,可以准确而高效地提取其等效电路模型,完成线缆的仿真计算。文章简述了 PEEC 方法的基本原理,并针对线缆的结构特点,对基本 PEEC 方法进行了相应的改进使其更加适用于线缆的等效电路建模。     

基于遗传算法的高效聚类挖掘新算法

提出了一种基于遗传算法的聚类数据挖掘新算法，并在某钢铁集团CIMS工程的销售管理系统中成功进行了应用，新算法与已有算法进行了对比研究。新方法对其他类似的实际应用也有参考价值。     

基于菜籽油的汽油机油基础油

考虑到可生物降解润滑油在润滑性能和生物降解性能两方面的要求, 选用菜籽油作为基础油, 并合理选用添加剂, 按照均匀设计方法, 安排多因素试验, 考察了润滑油抗氧化性能, 提出了10W/40SG级汽油机油的优化配方。进行了该配方与国外成品汽油机油的使用性能和可生物降解性能的对比试验, 结果表明, 其质量水平已达到10W/40SG的性能要求, 且生物降解性能优于同类矿物基润滑油。     

Comparative analysis of traveler destination choice models by method of sampling alternatives

In a destination choice model, it is important to introduce alternatives that have been adequately aggregated into traffic analysis zone levels based on spatial similarities and feasibility of analysis, because considering every spatial location possible for the traveler as an elemental alternative is intractable in terms of data management and analysis. In this study, we derive strata for alternative sets through simple random sampling and stratified importance sampling based on the concept of Moran’s I. As a result of comparative analysis, we are able to reduce errors by drawing an adequate number of samples for the destination choice model’s choice alternative sets based on measures of spatial similarity.     

基于塑性铰体外预应力混凝土梁的简化计算

在承载能力极限状态下,可把简支梁的跨中区段视为1个等曲率塑性铰(塑性区段),其余梁段可视为直线并处于绕塑性铰刚性转动的位置.利用这一概念,建立了直接通过塑性铰区长度和曲率半径求体外预应力筋应力和梁极限弯矩的简化公式,用简化公式对国外有关6片体外预应力梁进行了计算,并与试验结果进行对比,证明本研究中的简化公式具有较好的精度,值得推广.     

Wave Number Method for Three-Dimensional Steady-State Acoustic Problems

Based on the indirect Trefftz approach, a wave number method (WNM) is proposed to deal with three-dimensional steady-state acoustic problems. In the WNM, the dynamic pressure response variable is approximated by a set of wave functions, which exactly satisfy the Helmholtz equation. The set of wave functions comprise the exact solutions of the homogeneous part of the governing equations and some particular solution functions. The unknown coefficients of the wave functions can be obtained by enforcing the pressure approximation to satisfy the boundary conditions. Compared with the boundary element method (BEM), the WNM have a smaller system matrix, and is applicable to the radiation problems since the wave functions are independent of the domain size. A 3D acoustic cavity is exemplified to show the properties of the method. The results show that the wave number method is more efficient than the BEM, and it is fairly accurate.