双模式的交通拥挤收费模型研究

针对公交车和私家车辆两种交通模式,建立了交通拥挤收费的双层规划模型.在模型的阻抗函数计算中,考虑了两种模式之间相互影响及其车载能力的差异.以总体出行成本最小为目标建立上层模型、以用户最优的交通配流模型作为下层模型,出行模式的选择满足Logit模型.通过"对角化"算法直接搜索满足路径选择/模式选择的下层交通配流模型均衡解.通过步长加速和惩罚函数法对这个双层规划模型进行求解,最后给出了算例.     

考虑补货周期偏移的最优库存控制双层规划

研究了物流系统中多产品共用仓库的存贮策略.假设库存系统的平均总费用包括每次订货的固定订购费、产品所需仓库空间决定的固定存贮费,以及实际存贮产品数量决定的可变存贮费.通过多产品补货周期的相对偏移节省存贮空间和费用.最优库存控制双层规划模型中,以库存系统的平均总费用最小为上层目标,以库存系统所需的仓库空间最小为下层目标,上下层模型的决策变量分别为补货周期和补货周期的偏移量.设计了求解该模型的粒子群优化算法,求得最优补货周期和补货周期偏移量.用算例验证了模型和算法的有效性.     

奥运期间公交运营综合调度优化模型

奥运期间公交客流运输峰值变化后的调度管理受到人文奥运、绿色奥运的约束。以乘客满意度反映人文奥运的条件约束,以运力的成本最低、效率最大为实现绿色奥运的优化目标,而建立奥运期间公交客流调度优化的数学模型．可使各条线路在客流峰值变化的互补下实现综合平衡与优化。     

工程项目质量-工期-成本综合评价决策研究

工程项目决策问题是对质量、工期和成本三大目标的综合评价。传统的基于权重的决策方法存在各目标权重难以合理确定的问题。引入物理规划方法所建立的工程项目质量-工期-成本综合评价决策模型,是基于决策者设定的偏好,使得决策过程更加符合工程实际,避免了确定无实际物理意义的各目标权重,因而在公路桥梁工程项目决策中具有一定的应用价值。     

Approach of Separately Applying Unit Testing to AspectJ Program

A unit testing approach for AspectJ programs is proposed to separately test aspect units which have their own states. In the approach, aspects under test are converted to classes before execution of unit testing. In the conversion process, the context information passed through pointcut is transformed into advices, then the advices are converted to class member methods, and conflicts in the conversion result, if any, are resolved finally. The unit testing process consists of generating test cases, executing test cases and checking results.     

物流配送路线及配送时间的优化分析

运用运筹学中的动态规划算法研究实际生活中的配送线路优化问题。通过实际调研,绘制城市道路的网络图,并通过调查获得正常情况下的交通量数据,进而通过相应的方法计算出时间并赋予网络图时间权值;通过调查赋予网络图中距离权值,分别计算出配送时间的最优线路及配送路线的最优线路,并比较说明相应的实际问题。     

公交车辆合理配置的模糊随机机会约束规划模型

为城市合理配置一定数量且车型合理的公交车,不但可满足不同居民对交通工具的不同需求,而且可避免因车辆的空驶而导致的能源及道路资源的浪费．文章提出了一个公交车辆合理配置的混合机会约束规划模型,该模型以日载客容量最大为目标函数,同时考虑资金约束、道路资源约束及带有模糊随机参数的乘客需求约束,并引入了求解该模型的遗传算法。通过算例求解,说明了该模型及算法的合理性。     

Excel在数控编程中的应用

为提高数控编程效率,对于零件形状轨迹在以方程形式给出的情况下,用Excel表格的函数功能实现数值计算及数控程序生成,方法实用、简单、可行。     

Comprehensive pavement maintenance strategies for road networks through optimal allocation of resources

In order to maintain a growing road infrastructure at some minimum level of service, substantial resources are required on a recurrent basis. Of late, the available resources can no longer meet all the maintenance and rehabilitation demand even in wealthy nations. Hence, there is a need to develop a tool which will optimally allocate these resources in order to keep the road infrastructure as ‘healthy’ as possible. Further, this tool must acknowledge that maintenance needs are not only restricted to structural aspects but also extend to the functional- and safety-related aspects of a road. Here, such a comprehensive optimization tool is developed which when used will optimally allocate resources in order to maintain a healthy (from structural, functional, and safety standpoints) road network. The problem of determining the optimum maintenance and rehabilitation activities for individual road sections is formulated as a linear integer programming problem. Results from a case study using the proposed method show that the suggested maintenance and rehabilitation plans make sense from engineering and economic considerations.     

The location selection problem for the household activity pattern problem

In this paper, an integrated destination choice model based on routing and scheduling considerations of daily activities is proposed. Extending the Household Activity Pattern Problem (HAPP), the Location Selection Problem (LSP–HAPP) demonstrates how location choice is made as a simultaneous decision from interactions both with activities having predetermined locations and those with many candidate locations. A dynamic programming algorithm, developed for PDPTW, is adapted to handle a potentially sizable number of candidate locations. It is shown to be efficient for HAPP and LSP–HAPP applications. The algorithm is extended to keep arrival times as functions for mathematical programming formulations of activity-based travel models that often have time variables in the objective.