基于路段能力可靠性的城市交通网络设计

在介绍城市交通网络设计和概率用户平衡配流模型基本思想和内容的基础上,建立了考虑可靠性条件的城市交通网络设计双层规划模型,上层模型在投资约束条件下寻求系统总阻抗最小,下层模型兼顾路段能力可靠性与用户平衡配流条件,从而使城市交通网络备用能力最大,并针对该问题设计了可求得局部或全局最优解的混沌优化启发式算法,最后选用一个小型网络作为算例进行验证。结果说明该模型有一定的实际应用价值且设计的混沌优化算法也较为有效。     

单片机在电子车窗控制器中的应用设计

阐述电子车窗控制器的组成、功能、原理,介绍其研制过程、编程思想,并对软件、硬件可靠性作了分析。     

Optimization models for differentiating quality of service levels in probabilistic network capacity design problems

This paper develops various chance-constrained models for optimizing the probabilistic network design problem (PNDP), where we differentiate the quality of service (QoS) and measure the related network performance under uncertain demand. The upper level problem of PNDP designs continuous/discrete link capacities shared by multi-commodity flows, and the lower level problem differentiates the corresponding QoS for demand satisfaction, to prioritize customers and/or commodities. We consider PNDP variants that have either fixed flows (formulated at the upper level) or recourse flows (at the lower level) according to different applications. We transform each probabilistic model into a mixed-integer program, and derive polynomial-time algorithms for special cases with single-row chance constraints. The paper formulates benchmark stochastic programming models by either enforcing to meet all demand or penalizing unmet demand via a linear penalty function. We compare different models and approaches by testing randomly generated network instances and an instance built on the Sioux–Falls network. Numerical results demonstrate the computational efficacy of the solution approaches and derive managerial insights.     

基于多目标规划的公交车调度方法研究

公交调度要考虑公司和乘客的多方利益。目标规划法是运筹学中解决多目标问题的有效方法,而优先因子的采用可以区分调度中的各方利益的主次。同一优先因子下加入了权重,可根据实际情况做出灵活有效的调度方案。     

航道货运量预测方法及其应用

为了精确预测航道未来货运量需求,克服传统预测方法无法实现复杂非线性拟合的缺点,分析了航道货运量的影响因素,探讨了遗传规划方法在航道货运量预测问题上的应用.根据遗传规划巾复制、交换、变异等进化方式,建立了基于遗传规划的航道货运量预测模型.以江苏省连申线苏北段历年货运量及区域经济发展状况为样本,采用遗传规划方法自动找出货运量随时间变化的规律,并对未来货运量进行了预测.结果表明,本箅法的计算相对误差很小,预测结果合理可信,且优于常用的回归预测,为解决航道货运量等非线性系统预测提供了一条新的途径.     

A bi-objective dynamic programming approach for airline green fleet planning

Ensuring a fleet of green aircraft is a basic step in mitigating aviation pollution issues that are expected to be worsen in the coming years due to rapid air traffic growth. This study proposed a novel methodology in green fleet planning in which both profit and green performance of airline are considered simultaneously and explicitly. To do this, a Green Fleet Index (GFI) is derived as an indicator to quantify the green performance of airline’s fleet. It measures the degree of airline compliance with a standard requirement in terms of emission, noise, and fuel consumption. A bi-objective dynamic programming model is then formulated to find optimal aircraft acquisition (lease or purchase) decision by minimizing GFI and maximizing profit. Several interesting results are obtained: (1) considering environmental issue as secondary objective yields a greener fleet; (2) airline’s profit is affected, but could be recovered from environmental cost savings; (3) increasing load factor is an effective operational improvement strategy to enhance airline’s green performance and raise profit level. It is anticipated that the framework developed in this study could assist airlines to make a smart decision when considering the need to be green.     

Liner ship route schedule design with port time windows

This paper examines a practical tactical liner ship route schedule design problem, which is the determination of the arrival and departure time at each port of call on the ship route. When designing the schedule, the availability of each port in a week, i.e., port time window, is incorporated. As a result, the designed schedule can be applied in practice without or with only minimum revisions. This problem is formulated as a mixed-integer nonlinear nonconvex optimization model. In view of the problem structure, an efficient holistic solution approach is proposed to obtain global optimal solution. The proposed solution method is applied to a trans-Atlantic ship route. The results demonstrate that the port time windows, port handling efficiency, bunker price and unit inventory cost all affect the total cost of a ship route, the optimal number of ships to deploy, and the optimal schedule.     

二层线性规划的模糊数学解法(Ⅱ)

针对上层有约束条件、下层有Ｎ个独立的决策单元的二层线性规划问题，提出了一种模糊数学解法。首先，把这种规划分解为若干单层规划；然后引入隶属函数，用３个定理对各单层规划的解进行讨论，最终把这种二层线性规划转化为求解一个单层线必规划问题。使问题得到了简化。     

基于R树面向对象的航海资料数据模型

提出了基于面向对象技术和Ｒ树索引结构的航海资料数据模型。它通过面向对象技术的继承性有效地解决了信息存储的冗余问题，体现了航海资料的自然层次结构，与航海人员的思维定式相吻合。同时，通过Ｒ树建立了航海资料二维动态索引，实现了航海信息快速的查询。     

Containership scheduling with transit-time-sensitive container shipment demand

This paper examines the optimal containership schedule with transit-time-sensitive demand that is assumed to be a decreasing continuous function of transit time. A mixed-integer nonlinear non-convex optimization model is first formulated to maximize the total profit of a ship route. In view of the problem structure, a branch-and-bound based holistic solution method is developed. It is rigorously demonstrated that this solution method can obtain an ε-optimal solution in a finite number of iterations for general forms of transit-time-sensitive demand. Computational results based on a trans-Pacific liner ship route demonstrate the applicability and efficiency of the solution method.