体制变迁与供需失衡:铁路春运运力不足的结构性困境研究

铁路春运"一票难求"的表面原因是铁路运力不足,而运力不足的背后是深层次的社会问题,是人口流动背景下的春运客运需求激增、垄断体制下的铁路发展困境,以及因春节情结和公众选择偏好引发的放大效应等结构性困境。     

Shippers and freight operators perceptions of sustainable initiatives

The purpose of this paper is to document the extent to which Brazilian companies in retail channels have committed to adopting environmental sustainability measures, goals and strategies for waste disposal in the evaluation and planning of sustainable transportation. This paper also aims to examine the different viewpoints of sustainability issues and the preventive actions taken by companies in terms of controlling carbon dioxide emissions and proper disposal of tires, lubricant oils, accessories and spare parts. Finally, taking the perspective of these companies, this paper examines their difficulties in meeting environmental regulations. The research involved a survey completed by 185 representatives of different types of companies, including shippers (represented by manufacturers), LSPs (logistics service providers) and carriers. The non-linear canonical correlation was calculated to verify the opinions of these representatives from different companies regarding issues that impact on the environment, the preventive actions they adopt to reduce their environmental impact and their difficulties in meeting environmental regulations. The results show that shippers and LSPs have the same perceptions regarding these sustainability issues and preventive actions. In addition, the companies perceive high costs and the lack of training for their partners as the major challenges experienced in addressing these issues and undertaking preventive actions. Therefore they need to plan their transportation activities.     

联盟信任变迁与美韩联盟转型

联盟信任与联盟困境之间存在密切关系。在双边不对称联盟中,联盟困境的"抛弃"与"牵连"对联盟信任的作用更为强烈,进而成为推动联盟转型的重要变量。在美韩联盟发展过程中,其联盟信任不断变迁。联盟初期,由战火锤炼铸就的美韩双向情绪性信任,中经"尼克松冲击"转变为情绪性—工具性信任,后冷战时代历经双方的战略调整与实力变迁影响,转为双向工具性信任。受联盟信任变迁的影响,美韩联盟也实现了由军事联盟向战略性联盟的转变,这是联盟信任下降与共有利益拓展的共同结果。     

铁路总价承包合同管理存在的主要问题及对策

结合我国铁路总价承包合同执行现状，对铁路合同专用条款中存在的承发包双方法律地位不对等、工程款拨付比例不切实际、总承包风险费严重不足等主要不合理内容进行剖析，说明不合理的原因。对发包人处理正负量差的方式、工期调整产生的赶工费不能全额解决及部分变更设计在源头上得不到认可等在合同执行过程中存在的问题进行研究。简单分析产生不合理条款和合同执行不到位的主要原因。针对这些不合理条款，提出应对策略。     

考虑储存成本的集装箱公铁联运路径优化

联运企业的效益受运输路径和运输方式的影响。如何降低联运成本、提高联运企业的效益,已成为学术研究的重中之重。针对集装箱公铁联运路径优化问题,以运输成本、换装成本、储存成本、时间惩罚成本构成的运输总成本为目标函数,建立集装箱公铁联运路径优化模型,考虑运输时间限制、班期限制、节点储存成本,得出使运输总成本最低的运输路径及运输方式,并利用算例验证模型的有效性。     

党政机构微博在突发事件中传播效果的影响因素及策略

在分析铁路货运量预测方法的基础上，针对标准BP神经网络的不足，提出改进的BP神经网络预测模型。首先,利用动态陡度因子来改变激励函数的陡峭程度，以此来得到更好的激励函数响应特征以及更好的非线性表达能力；其次，利用附加动量因子，通过对以前经验的积累，既降低了神经网络对误差曲面的局部细节敏感特性，又较好的遏制了神经网络易于限于局部最小的缺陷；最后，采取改变学习率的方法，给定一个较大的学习率初始值，在学习的过程中学习率不断减小，网络最终趋于稳定。改进BP算法既可以得到更优的解，还能够缩短训练时间。利用全国铁路货运     

1906-1908年的郑孝胥与预备立宪公会

考虑到我国未来年度的OD分布预测中的路网构成变化、区域经济布局变动、区域经济增长速度差异等一些具有时变性和特殊性因素，采用在“四阶段法”运量预测基础上改进而成的“三阶段法”进行高速铁路短期客运量预测。首先采用组合预测模型进行趋势运量预测，然后采用多元LOGIT模型进行方式分担，最后采用弹性系数诱增模型进行诱增运量预测。以京沪高铁为例，采用“三阶段法”预测了2014年和2015年京沪高铁本线及跨线单向客流量。     

Minimization of passenger takeoff and landing risk in offshore helicopter transportation: Models,approaches and analysis

Offshore petroleum industry uses helicopters to transport the employees to and from installations. Takeoff and landing represent a substantial part of the flight risks for passengers. In this paper, we propose and analyze approaches to create a safe flight schedule to perform pickup of employees by several independent flights. Two scenarios are considered. Under the non-split scenario, exactly one visit is allowed to each installation. Under the split scenario, the pickup demand of an installation can be split between several flights. Interesting links between our problem and other problems of combinatorial optimization, e.g., parallel machine scheduling and bin-packing are established. We provide worst-case analysis of the performance of some of our algorithms and report the results of computational experiments conducted on randomly generated instances based on the real sets of installations in the oil fields on the Norwegian continental shelf. This paper is the first attempt to handle takeoff and landing risk in a flight schedule that consists of several flights and lays ground for the study on more advanced and practically relevant models.     

Client Personality,Working Alliance and Outcome

Abstract

The relationship of the five-factor model of personality to working alliance, symptoms and well-being was examined in a diverse community mental health sample (N = 103). Agreeableness, openness, extraversion and conscientiousness were associated with alliance. Neuroticism was strongly associated with symptoms, and negatively associated with well-being. Extraversion was moderately associated with well-being. Personality is deserving of further study as a potentially important influence on therapy process and outcome. Part of the much-replicated association of alliance with outcome may be accounted for by personality. Implications for social work practice and research are discussed.     

热贡鲁若中"玛泽"与藏族历史的渊源关系

文章从历史学、宗教学、民俗学等角度,将流行于黄南藏族自治州同仁县隆务河流域的六月会主体节目之一"玛泽"的文化内涵进行了新的探讨,并就"玛泽"节目的历史和宗教渊源关系,民俗形成过程,以及对军事、生产活动中的意义提出了自己的看法.