客运专线、高速铁路异物侵限监测方案优化

结合国内客运专线、高速铁路异物侵限监测系统的应用现状,详细分析了我国客运专线、高速铁路异物侵限监测系统监测手段、监测网安装方式、监测网防护对象、监测范围等,明确提出了适合我国客运专线、高速铁路异物侵限监测系统的建设方案优化建议。     

Selection of Mergers and Acquisitions by Foreign Capital in Open Economies

IntroductionIn recent years, large quantities of multinationalcorporations ( MNCs) compete for publicly tradedcompanies in mainland china, which gives domesticfirms more alternatives, and increases their economicbenefit. With their different impacts on me…     

伺服滑台驱动系统的设计

从伺服滑台驱动系统的构成讲起,简述其工作原理及在焊装行业的应用情况。阐述驱动系统性能对伺服滑台实现其功能的重要性。介绍伺服滑台驱动系统设计的一般流程,并对设计过程中的齿轮齿条副设计、伺服减速电机和滚珠导轨副选型以及润滑组件设计4个主要步骤做了较全面和详细的说明,提供一套较完整的伺服滑台驱动系统的设计方法。     

Selection bias in build-operate-transfer transportation project appraisals

Recent empirical studies have found widespread inaccuracies in traffic forecasts despite the fact that travel demand forecasting models have been significantly improved over the past few decades. We suspect that an intrinsic selection bias may exist in the competitive project appraisal process, in addition to the many other factors that contribute to inaccurate traffic forecasts. In this paper, we examine the potential for selection bias in the governmental process of Build-Operate-Transfer (BOT) transportation project appraisals. Although the simultaneous consideration of multiple criteria is typically used in practice, traffic flow estimate is usually a key criterion in these appraisals. For the purposes of this paper, we focus on the selection bias associated with the highest flow estimate criterion. We develop two approaches to quantify the level and chance of inaccuracy caused by selection bias: the expected value approach and the probability approach. The expected value approach addresses the question “to what extent is inaccuracy caused by selection bias?”. The probability approach addresses the question “what is the chance of inaccuracy due to selection bias?”. The results of this analysis confirm the existence of selection bias when a government uses the highest traffic forecast estimate as the priority criterion for BOT project selection. In addition, we offer some insights into the relationship between the extent/chance of inaccuracy and other related factors. We do not argue that selection bias is the only reason for inaccurate traffic forecasts in BOT projects; however, it does appear that it could be an intrinsic factor worthy of further attention and investigation.     

武汉铁路枢纽建设施工组织计划

武汉铁路枢纽地处京广通道和沪汉蓉沿江经济带的交叉点,是铁路快速路网中心之一,衔接五个方向的铁路大型枢纽。为解决武汉铁路枢纽内过江通道能力不足、客运系统现状不能适应京广客运专线和沪汉蓉快速通道引入、解编能力不足的矛盾“,十一五”期间,武汉铁路枢纽有八大工程相继开工建设,各建设项目相互交错,工期相互影响。为使各建设项目协调进行,制定全面的施工组织计划,分析控制枢纽施工的各种因素,抓住重点控制工程,是确保武汉铁路枢纽按时建成通车的关键。     

Assessing transportation user benefits with maximum trip lengths

Maximum time lengths of urban trips can be used to calculate major user benefits of transportation improvements. These benefits include those associated with reduced cost of travel, those associated with travel to additional destinations, and those associated with improved quality of destinations. Maximum trip lengths can be measured using techniques of psychological scaling.     

GSM-R基站天线的选型分析

简要介绍GSM-R系统基站使用的天线和应用方式,通过测试数据说明选用不同天线对覆盖效果的影响.特别提出了减小天线下倾角的重要性,以及天线下倾角调谐方式对减少同频干扰的作用.     

船舶涂装冲砂派工精细化研究

精细化管理是现代企业所追求的管理模式,在精细化管理下,员工个人能力得到合理安排,整体工作效率得到提升.冲砂作业是涂装作业中重要一环,其精细化派工的实现有利于涂装效率的提升.本文通过对冲砂作业进行分析,研究了不同因素对冲砂效率影响,其中着重研究了作业环境所造成工作人员不同姿势及其对效率的影响,综合分析冲砂作业在不同姿势下的作业效率,并对涂装设计提出改进建议,从而为精细化派工提供了依据.     

京津冀地区城际快速铁路网形成要素分析

研究目的：在京津冀地区城际快速铁路网规划的基础上，结合城际铁路的客流特点及功能定位分析，着重分析论述这一区域形成规划的城际快速铁路网的主要要素。 研究方法：结合城际铁路客流特征及功能定位分析，通过对该区域社会经济、城市群及交通经济带这三方面要素现状存在的主要问题及未来发展趋势分析论述，确定支撑区域城际铁路网的主要要素。 研究结果：京津冀地区社会经济、城市群及交通经济带形成与发展方面具有得天独厚的区位优势和资源优势，这三个要素的形成与发展必将带来区域内各城市问商务、旅游、探亲等人员出行次数的增加，从而形成强大的区域内城市之间旅客交流，支撑规划的该区域城际快速铁路网。 研究结论：社会经济、城市群及交通经济带形成与发展是支撑该区域城际快速铁路网形成的主要要素。     

扩大长江干线航道通过能力研究

城区段河道规划是关系到城市人民财产、生命安全的重要方面,更是提升城市品位,提高人民生活质量的根本。本文就整体规划方案分析,使水利工程向“美、靓、实”的方向规划,供大家共同探讨。