轻型货车转向架试验简介

介绍了为美国315K货车开发的轻型转向架在FAST试验线的试验结果.     

Plate scanning tools to obtain travel times in traffic networks

The management of vehicle travel times has been shown to be fundamental to traffic network analysis. To collect travel time measurement, some methods focus solely on isolated links or highway segments, and where two measurement points, at the beginning and at the end of a section, are deemed sufficient to evaluate users' travel time. However, in many cases, transport studies involve networks in which the problem is more complex. This article takes advantage of the plate scanning technique to propose an algorithm that minimizes the required number of registering devices and their location in order to identify vehicles candidates to compute the travel times of a given set of routes (or subroutes). The merits of the proposed method are explained using simple examples and are illustrated by its application to the real network of Ciudad Real.     

先进的铁道车辆检查系统

先进的铁道车辆检查系统能提高铁路的安全性、降低成本并改善客户服务.本文重点介绍了闸瓦和车轮轮廓检查系统的试验、现场考验和运用情况.     

Correcting injection pressure maladjustments to reduce NOX emissions by marine diesel engines

Emissions from the exhausts of marine diesel engines comprises several different gases including NO_X. These are currently regulated at the international level under Regulation 13 of ANNEX VI of MARPOL 73/78, but this regulation only applies to new engines and is based on bench tests, for only a single engine designated the “parent engine”. Here, the need to take measurements from across their whole range and once in operation on board a vessel is examined. This would not only improve assessment of new equipment against the current regulation, but would also detect defects in the functioning of the engine.     

A practical assessment of stated preferences methods

Stated preferences data in the form of rankings, ratings and choices were collected in Santiago and discrete choice models estimated with them. The models were compared in terms of accuracy v/s the cost of obtaining the information and models. All methods produced reasonable but different models and fairly close subjective values of time. In terms of production costs the ranking method was a clear looser although the experimental design was slightly biased against it. Finally, the use of computerised interviews is highly recommended particularly for dealing with low income people.     

胎儿中枢神经系统畸形的超声诊断及其形成机理

中枢神经系统畸形是胎儿畸形的重要部分 ,可导致胎儿死亡 ,给孕妇及家庭带来巨大的痛苦。及早准确地发现各种中枢神经系统畸形 ,对临床及时处理、治疗以及优生优育均有着极其重要的价值。1　资料与方法1.1　临床资料　 148例孕妇胎儿中枢神经系统畸形为1993～ 1998年美国加州奥克兰ＡｌｔａＢａｔｅｓ产前诊断中心的孕妇超声检查结果 ,所有病例均经引产后病理或生后证实为中枢神经系统畸形 ,年龄 2 0～ 41岁 ,孕龄 15～ 39周。1.2　主要仪器及方法　美国Ａｃｕｓｏｎ - 12 8、Ａｃｕｓｏｎ -12 8ＸＰ5以及Ｓｅｑｕｏｉａ彩色电脑声像仪。按…     

工程建设项目中的信息管理

从工程建设项目管理的角度阐述了项目中信息流的组成、项目信息的交换过程和项目信息管理的特征，并提出了项目信息管理的任务。     

A Strategic Diagnostic Tool Applied to Iberian Seaports: An Evolutionary Perspective

The highly competitive and rapidly changing environment faced by businesses has greatly increased the need for strategic planning. The importance of formulating strategies to reach competitive advantages with implications in the performance is becoming increasingly evident in the seaport context. Thus, it is relevant and appropriate to apply strategic positioning tools to seaports given the role of competitive strategies in the growth and development of this industry. This research aims to analyse the strategic positioning of the leading Iberian Peninsula seaports (Portuguese and Spanish seaports) using the Boston Consulting Group (BCG) matrix as a strategic tool in an evolutionary perspective. The portfolio analysis developed subsequently focuses on the annual data of eight seaports in a selected period of 18 years (1992–2009) and on five categories of traffic: liquid bulk (LB), dry bulk (DB), containers (CO), ro-ro (roll-on/roll-off) and conventional cargo (CC). This research allows us to compare and analyse different levels of performance and identify which of the seaports have improved their strategic positioning during the considered period. The findings reveal a better positioning of Spanish seaports in relation to total traffic and that most of the seaports in the BCG matrix had changed from the first to the third period. The seaport of Valencia is the only one that has maintained its Star Performer position in all the 18 years analysed. Furthermore, considering container traffic, the results evidence the seaports of Algeciras, Valencia and Barcelona as having attained a remarkable position of leadership.     

Do maritime passengers’ subsidies in Europe affect prices?

Some European governments subsidize their residents when they travel at sea. This paper seeks to analyze the impact on prices of maritime passengers’ subsidies in Europe. Following a review of the scarce academic literature on this topic and the subsidy scheme in Europe, a sample of firms’ prices and other characteristics of 40 European routes for 2016 are analyzed. Both an estimation of a price equation and a matching approach are applied and reach the same conclusion: prices per kilometer are around 40 per cent higher on those subsidized routes due to subsidies. This outcome reduces the potential subsidy gain to consumers.