横张预应力砼研究工作综述

概要介绍了横张预应力砼的施工方法、原理及现有研究工作 .研究和实践表明横张预应力砼在保持常规后张预应力砼良好的力学特性的条件下 ,能明显节省钢材、简化工艺、提高工效 ,具有很好的技术经济效益     

A trial application of FSA methodology to the hatchway watertight integrity of bulk carriers

Formal safety assessment (FSA) is a formal, structured and systematic methodology, aimed at enhancing maritime safety, including protection of life, property and marine environment, by using risk and cost–benefit assessments. For the application of this methodology to the rule-making process, the International Maritime Organization (IMO) presented the Interim Guidelines, which describe procedures of FSA and inputs/outputs of each procedure in detail. This paper basically deals with an application of FSA methodology according to the IMO's Interim Guidelines to the hatchway watertight integrity of bulk carriers, which was carried out as a cooperative research between Korean Register of Shipping and Seoul National University. As results of this application study, 18 hazards are identified and 32 risk control measures are devised to reduce the associated risks. Potential risks, costs and benefits when some Risk Control Options are introduced are evaluated in monetary unit of US $. Finally, some discussions and recommendations based on experiences are also given for both future work and better application of this FSA methodology to the rule-making process.     

屏蔽门系统在地铁中的应用前景

结合香港地铁、广州地铁屏蔽门系统的设计实际,阐述屏蔽门系统在地铁中的功能以及社会效益、经济效益,并指出屏蔽门系统在今后地铁新线建设及旧线改造中的应用前景。     

中国、俄罗斯地铁规划及相关预埋建设的对比

考察了俄罗斯地铁,结合城市轨道交通线网规划、运营管理工作,分析规划指标、建设预留与运营效益关系的规律,对比两国的差异,探讨适合中国国情的线网模式,以及决策、建设与线网功能的关系。     

SMA广泛运用于福建省高速公路的可行性研究

通过对进口材料经费进行的经济效益和社会效益的分析,最终得出结论:采用SMA新技术,虽然投资初期的花费较高,但由于它特有的优势和性能,能通过防止早期破坏、减少维修养护、延长使用寿命等方面得以回报。因此,SMA路面在福建省有着广泛的应用前景。     

公路沥青路面预防性养护技术研究

以相关研究成果为基础,对公路沥青路面预防性养护的各项关键技术进行系统研究和阐述。以理论分析为主,结合室内试验和试验路观测,明确了路面预防性养护的定义和技术理念;分宏观和微观两个层面提出了公路沥青路面预防性养护的路况指标和标准;建立了预防性养护对策及措施选择的方法和流程,并给出了相应示例;以路面预养护措施的费用效益分析为核心提出了最佳预防性养护时间的确定方法和相关参数。该文提出的理论、方法、技术和参数初步建立了我国路面预养护的技术框架,可供相关的研究和应用参考。     

橡胶沥青应力吸收层的效益分析

废胶粉在公路工程中应用范围很广,通过对橡胶沥青应力吸收层、聚酯玻纤布应力吸收层和乳化沥青封层三种施工工艺的经济效益进行计算和对比,并详细介绍橡胶在沥青应力吸收层中的应用,对于解决社会环保问题、提高道路的经济效益具有重要意义。     

关于公交停靠站影响区范围的研究

随着城市公共交通系统的发展,公交停靠站对道路交通流的影响已逐渐引起人们的注意。分析公交停靠站的影响首先应该对停靠站的影响区范围进行界定。在分析前人研究成果的基础上,基于交通波理论,按考虑超车与否,分析公交停靠站的影响区范围长度,得到不同交通流密度条件下公交停靠站影响区长度的计算公式。     

汽车综合性能检测站经济效益分析

黑龙江省汽车综合性能检测站数量已逐渐趋于饱和,有些地区建站后即面临亏损,为避免投资失误并减少投资浪费,有必要对检测站的效益进行分析研究。主要分析了检测站的基本投资、基本支出和收入来源,通过逐项列举和估算,可以对检测站建站的可行性有详细认识,为最后决策提供参考。对经济效益的若干影响因素进行分析,为经营者增加效益提供帮助。     

On incentives and optimal effort to improve bus transit performance

ABSTRACT

This paper studies incentive-based subsidy to transit systems to improve performance. It derives a formula for optimal effort that equalizes marginal cost and marginal benefit and derives some principles from it among which is that the larger the value of a transit system’s performance criterion the larger the effort it will exert to improve it. Next, using a constrained cost minimization approach it derives a nonlinear cost function that includes optimal effort and estimates it using an unbalanced panel data of single mode U.S. bus transit systems. The results show that optimal effort is the equivalent of seven full-time employees (15,243 labor hours) per year and in real terms it results in 0.6% cost saving (US$198,331) and US$836,796 in incentive subsidy per observation. The implications of these findings are examined.