An AI-based approach for transit route system planning and design

We present an AI-based solution approach to the transit network design problem (TNDP). Past approaches fall into three categories: optimization formulations of idealized situations, heuristic approaches, or practical guidelines and ad hoc procedures reflecting the professional judgement and practical experience of transit planners. We discuss the sources of complexity of the TNDP as well as the shortcomings of the previous approaches. This discussion motivates the need for AI search techniques that implement the existing designer's knowledge and expertise to achieve better solutions efficiently. Then we propose a hybrid solution approach that incorporates the knowledge and expertise of transit network planners and implements efficient search techniques using AI tools, algorithmic procedures developed by others, and modules for tools implemented in conventional languages. The three major components of the solution approach are presented, namely, the lisp-implemented route generation design algorithm (RGA), the analysis procedure TRUST (Transit Route Analyst), and the route improvement algorithm (RIA). An example illustration is included.     

Driver-Vehicle-Lateraldynamics under Regular Driving Conditions

In order to minimize accidents and achieve comfortable handling it is necessary to analyse the control behaviour of the driver-vehicle system and adapt the vehicle to the driver. However, most of the tests have shown, that under normal driving conditions the driver adapts himself to the vehicle, which is exactly the other way round as it was originally thought. In this paper it would be shown, how the driver adapts himself to the vehicle and which technical parameters may effect this adaptation.     

A study of the dynamic response of submerged rectangular flat plates

The dynamic response of flat horizontal plates vibrating in air and under water has been investigated experimentally and analytically. The effect of the boundary conditions and the depth of submergence of the plates has been studied. Excellent agreement was obtained between the analytical solution and the experimental results. An approximate expression for the evaluation of the modal added masses for rectangular plates has been derived. This can be used to estimate the natural frequencies of plating constituting the internal structure within the cargo spaces in tankers and liquid cargo carriers.     

电力电子装置在混合电动汽车中的应用

混合电动汽车由于其性能和经济上的优势,比纯电动汽车得到更多的用户认可.现在全球两大汽车公司在世界上大多数地区销售的混合电动汽车累计超过12万辆.尽管纯电动汽车在道路运输和短途交通中可得到适当应用,但与非混合的汽车相比,混合电动汽车非常实用,燃料可节省5%～50%,甚至更多.现在由于交流传动使用寿命长,易于采用电力电子控制,它普遍用于混合动力系.但是,因为汽车推进系统独特的应用要求,目前的交流传动还难以满足整个驱动系统性能要求,且达不装置的体积目标.所以,目前混合动力系仍然使用容量过大的电机或电力电子装置的交流传动.本文基于这样的前提:解决混合电动汽车交流传动的宽恒功速比(CPSR)和整体性能最经济的办法是建立在电力电子装置基础上的.文章主要介绍变速装置方面的现状,以及为了提供与客运汽车更好匹配的交流传动装置正在作哪些努力.     

An analysis of the pricing system in the Greek-Italian coastal routes

Price discrimination is practiced by oligopolistic coastal shipping companies in the 'unregulated' Greece-Italy routes in the year 2002. Investigation has been carried out 'per route'—in a doctoral thesis—instead of 'per market' which was the so-far erroneous approach of shipping economists. This is so for a host of differentiating factors play a considerable and non-negligible role (like geography, distance, demand, seasonality and others). Service—and price-discrimination—in coastal shipping is affected also by the predetermined ship design which thus is a special feature—but not exclusively—in coastal shipping. Companies in the Adriatic Sea try to extract the greater possible value of the user's willingness to pay, peak and off-peak, group and ungrouped, for social groups (clubs, families and students). Marketing and economics interfere in a complicated—far from the nice world of theory—situation, where maximization of revenue and profit, capacity utilization, intense seasonality and high fixed cost (common and joint costs as well) are a few of the factors that interplay. This paper can be considered as a case study for applied pricing. Excess capacity is also a strategic factor affecting pricing. It is our opinion that the analysis here gives for the first time a complete theoretical and practical account—based on the price lists of the companies—of the pricing policy of the ferry boats running in the Adriatic Sea belonging to coastal shipping companies connecting Italy with Greece and Greece with the European Union (EU). We believe this work to be useful for maritime Europe.     

大功率多流制机车牵引变流器的比较

欧洲铁路的显著特点是供电电流制式范围较广.为使电力机车运行灵活且在不同制式交界处暂停时间较短,有必要使用多流制机车.比较了多流制变流器的各种方案,并介绍了基于最新的大功率IGBT技术的一种很有价值的方案.     

An introduction to airport APM systems

The purpose of this paper is to provide an introduction to the nature and purpose of airport automated people mover (APM) systems. Our objective is to provide a convenient research tool for persons seeking an introduction to the airport APM industry. Included are illustrations of typical system designs; a listing of existing airport APM systems, including a tabular presentation of selected data; an organization and discussion of the history and evolution of the existing systems; and a status report on current developments in the APM industry.     

Grounding experiments on soft bottoms

To verify a theoretical analysis procedure for calculation of the hull girder response of ships running aground, a series of large-scale ship grounding experiments was performed on an artificial island made of engineered fill. The tests were conducted by running a condemned fishing vessel up on selected beaches of the island with velocities ranging between 2m/s and 5.5m/s. During the tests, surge, heave, and pitch accelerations were measured and also the deformations of the beach and the ship bow. Based on these accelerations, rigid body velocities and motions were determined. The forces arising from the interaction between the bow of the vessel and the seabed were determined by solving the equations of motions. This article describes the analysis of the measured results and a comparison of the results from the full-scale measurements with results from a recently developed analysis procedure for grounding on soft bottoms. Presented at the International Conference on Technology for Marine Environment Preservation (MARIENV '95), Tokyo, Japan, September 24–29, 1995.