Optimal Control of the Tractor-Semitrailer Truck

This paper is concerned with the braking performance and the handling behavior of the tractor-semitrailer truck under optimal braking. Optimal control theory is used in order to deal with the problem and a combination of the steepest descent method and the Davidon Fletcher Powell method is used to solve it numerically. Results for some chosen braking maneuvers are obtained for a nonlinear truck model which has 14 degrees of freedom. These results show that, for the chosen maneuvers an idealized anti-skid braking is close to being optimal in the sense defined in this paper. Implementation of an idealized anti-skid braking on the tractor-semitrailer truck, however, may be not desirable.     

Use of the analytic hierarchy process to evaluate transit fare system

The transportation fare system influences the mobility of a region and the life quality of its inhabitants. This study aims to evaluate a region's optimal fare system by using the analytic hierarchy process, based on a survey among transportation experts, divided into three categories: operators, professors/consultants and government officials. The results are presented divided by category and overall, and the performance of the most important relative criteria to establish a fare system is determined. The most important criterion according to all the selected experts was the fare price, with 21.5%. The fare system determined as the best was distance/zone (31.1%) and the worst was a flat fare system (7.2%). In addition, we show the influence of the fare price criterion in each fare system through sensitivity charts and highlight its importance for all three groups of experts to evaluate the fare system.     

How to Write a Literature Review Paper?

This paper discusses the question about how to write a literature review paper (LRP). It stresses the primary importance of adding value, rather than only providing an overview, and it then discusses some of the reasons for (or not) actually writing an LRP, including issues relating to the nature and scope of the paper. It also presents different types of LRPs, advises on reporting the methodology used for the selection of papers for review, and the structure of an LRP. An important conclusion is that the heterogeneity in LRPs is very large. This paper also presents some of the aspects that the authors feel are important structural and contextual considerations that help produce high-quality review papers.     

Practicability study on the suitability of artificial,neural networks for the approximation of unknown steering torques

For steer-by-wire systems, the steering feedback must be generated artificially due to the system characteristics. Classical control concepts require operating-point driven optimisations as well as increased calibration efforts in order to adequately simulate the steering torque in all driving states. Artificial neural networks (ANNs) are an innovative control concept; they are capable of learning arbitrary non-linear correlations without complex knowledge of physical dependencies. The present study investigates the suitability of neural networks for approximating unknown steering torques. To ensure robust processing of arbitrary data, network training with a sufficient volume of training data is required, that represents the relation between the input and target values in a wide range. The data were recorded in the course of various test drives. In this research, a variety of network topologies were trained, analysed and evaluated. Though the fundamental suitability of ANNs for the present control task was demonstrated.     

On the development of public transit in large cities

This article presents a summary of the analyses and set of recommendations given by a committee of transit specialists gathered by the Minister of Transport of Chile aiming at improving Transantiago, the new transit system recently inaugurated for Santiago. This summary focuses on those recommendations directed towards improving the efficiency, service quality and sustainability of mass public transportation systems in major cities in the developing world and that could be implemented in a short term (within two years). Three broad dimensions of public transit are considered: competition and regulation; investment, financing, fares and subsidies; and the operation and use of infrastructure, design, inspection and control. Although the study grew out of the needs and characteristics of a city such as Santiago (Chile), and of the virtues and deficiencies of Transantiago, much of the analyses and recommendations could be adopted and implemented in the major cities of developed countries in Europe, North America and Asia.     

公司交通政策的最佳实践——以比利时为例

公司是通勤交通的主要创造者,在与交通相关的讨论中,公司扮演着重要角色。近几年,公司提出了多种政策措施,以改善员工的出行条件,但其愿景与行动通常被研究文献所忽视。为了讨论比利时公司在交通政策方面的最佳实践,分析了现有研究成果和比利时的两次大规模通勤交通调查。首先,对公司进行分类,以便确定在推广替代交通方式方面受员工欢迎的公司。然后,通过量化分析确定交通政策的最佳实践。结果显示,最佳替代交通方式取决于公司特征;自行车交通最适合小型工作场所,大型工作场所和位于建筑密集区或市中心的公司则更适合推广公共交通;在公司交通管理中,财务激励、设施提供、信息传播和停车管理均起重要作用。     

Scenario analysis for supply chain integration in container shipping

Competition in the business world nowadays is largely between supply chains, rather than individual players only. The same situation exists in container shipping. The study looks into container shipping from an integrated perspective and investigates the nature and level of supply chain integration in container shipping. Based on empirical examinations of the world's top 30 container shipping lines, a scenario analysis is conducted. The paper aims to present the scenario analysis for examining supply chain integration in container shipping. It also aims to formulate strategic recommendations for liners to create and sustain competitive advantage. The scenario analysis is designed to allow more complete consideration of alternative possible outcomes and their implications on the research topic. It involves an evaluation of past and present events and provides a plausible discussion of what might occur in the future. It depicts four scenarios of supply chain integration in container shipping, namely, low integration, partner-focused integration, activity-focused integration and high integration. On the whole, research findings suggest that market situations favour those scenarios representing higher level of supply chain integration. Importantly, with reference to the scenario analysis, shipping lines should position themselves in an appropriate scenario and formulate strategic plans accordingly.     

Part 2. Beyond single-outcome models: Decompositions of aggregate and disaggregate road safety risk

The second part of the state-of-the-art focuses on the development of the founders' double streams explaining single-outcome indicators (probability of accidents and fatalities, respectively) by fixed form regression, as outlined in the Part 1. Following Page (1997, pp. 67–122, 2001) and others, we use as turning point of the evolution of both aggregate and discrete approaches the DRAG-1 model of 1984, itself based on aggregate data, which introduced four key innovations in principle applicable to both streams.