Methodology to determine service delivery levels for public transportation

When designing transit services, the Level-of-Service concept has been widely used by transport planners and service providers to assess the service quality of an existing transit system. In addition to the service quality assessment, service providers also need to estimate the service levels that will satisfy a maximum number of users and potential users, across all socio-economic groups, so as to maximize patronage. This paper demonstrates a method using the concept of ‘user satisfaction levels’ and their ‘zone of tolerance’, along with total utility and marginal utility for service providers, to provide a range of service delivery levels for individual transit service attributes in the city of Kolkata. This range of service levels provides a guideline for service providers within which they can consider making an improvement in service level. However, the final decision on service improvement is an outcome of both financial and infrastructural feasibility.     

基于BP神经网络确定最优配送车辆数目问题的研究

在介绍BP神经网络相关知识的基础上,建立用于确定最优配送车辆数目的三层BP神经网络,给出BP神经网络的学习步骤。并通过实例对基于MATLAB的神经网络工具箱的可行性加以验证,对于相关研究具有十分重要的指导意义。     

美军低成本空投系统(LCADS)分析及对我军的启示

简单介绍了美军空投系统的发展及建设情况,回顾了美军传统空投系统(CDS)的使用情况及存在问题,着重分析了新型低成本空投系统(LCADS)的适用性强、适用范围广泛等特性。在此基础上,从使用成本、使用效果等方面对LCADS与CDS进行了比较分析。最后根据美军空投系统的发展现状及趋势,提出了加强我军空投系统建设的几点启示,有利于促进我军后勤保障方式的发展变革。     

粉粒物料罐车的型谱分析

经过整理将粉粒物料罐车罐型汇总成表,通过图表的形式展现粉粒物料罐车发展过程,并且提出一个基于罐体受力分析的分类方式。     

Optimizing express parcel networks and delivery schemes subject to timeliness tolerances

The ‘first come first served’ (FCFS) strategy usually adopted by air express companies does not consider delivery time tolerances and induces underuse of some facilities. This study relaxes the time tolerances and tackles the issue of parcel deliveries and transport network design for an express delivery company. In other words, it determines simultaneously the route loops of company-owned cargo aircraft, the amount of cargo space chartered for each link and the parcel delivery paths. Using a case study in which parcels must be delivered between 14 cities served by the SF Air Express Company, we find that FCFS is not the best approach for minimizing costs and that express companies can optimize both their delivery schemes and networks subject to some relaxed time tolerances.     

单配送中心快递企业共同配送车辆鲁棒调度研究

考虑到不确定因素在快递企业共同配送车辆鲁棒调度问题中广泛存在,为了改善快递企业的服务水平,并缓解快递派送中由于不确定因素带来的客户满意度低的现状,采用鲁棒离散理论的相关知识,建立了车辆路段等待时间不确定情形下的单配送中心快递企业共同配送车辆调度的多目标鲁棒优化模型,然后根据转化规则,将鲁棒优化模型转化为确定型优化模型,并采用改进的遗传算法对其进行求解。结果表明,快递企业采用共同配送模式可以有效降低成本,节约时间,而且企业决策者可以根据所考虑的不确定性值G 的大小,选择自己偏好的车辆调度方案。     

基于交叉感应环线的车地通信系统专项测试研究

基于交叉感应环线的车地通信系统(简称TWC系统)专项测试包括产品功能测试和产品交付测试.TWC系统专项测试能更有针对性、更高效的发现TWC系统软件功能和系统硬件的缺陷.将对TWC系统专项测试的必要性进行探究,并针对不同型号的TWC设备,从仿真环境搭建、测试内容选取、测试案例实现等方面对TWC系统专项测试方法进行详细研究...     

混凝土输送泵长距离泵送技术的应用

通过对隧道二次衬砌机械配套施工模式的技术经济分析,阐述了短隧道二次衬砌采用混凝土长距离泵送技术的可行性。为充分发挥混凝土输送泵的效率提供了参考,也为隧道施工项目的安全质量和成本控制提出了较好的建议。     

PREVENTING RESTENOSIS FOLLOWING PTCA

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《鹿特丹规则》货物交付制度若干新变化之比较研究

货物交付制度是运输合同法律的重要内容。《鹿特丹规则》系统规定了货物交付制度,确立了收货人接收交付和确认收到货物的义务,规定了不同运输单证下的交付规则,与现行的法律比较存在诸多差异。中国航运企业应研究、借鉴货物交付新规则,完善货物交付制度。