Switching service types for multi-region bus systems

Conventional fixed-route bus services are generally preferred to flexible-route services at high demand densities, and vice versa. This paper formulates the problem of integrating conventional and flexible services that connect a main terminal to multiple local regions over multiple time periods. The system’s vehicle size, route spacing (for conventional services), service area (for flexible services), headways and fleet sizes are jointly optimized to minimize the sum of supplier costs and user costs. The route spacing for conventional bus services and service area for flexible bus services are also optimized for each region. The proposed solution method, which uses a genetic algorithm and analytic optimization, finds good solutions quickly. Numerical examples and sensitivity analyses confirm that the single fleet variable-type bus service may outperform either the single fleet conventional bus service or the single fleet flexible bus service when demand densities vary substantially among regions and time periods.     

Revisiting port pricing; a proposal for seven port pricing principles

A review of seven large landlord port authorities around the world reveals a notable diversity of pricing structures. While port authorities increasingly act as commercial undertakings, port pricing often seems to be not driven by commercial considerations. In this paper, we argue that ports can be regarded as “business ecosystems” with multiple users. This provides a valuable perspective on pricing and raises the question of whether ports can be regarded as two-sided markets. We argue this is not the case. The business ecosystem perspective provides a basis for deducing seven pricing principles for port authorities that are detailed in the paper and illustrated with cases these principles. These pricing principles are broadly follow a direct user pays approach; capture value from “non-core” tenants; price aggressively for activities with a high strategic value; differentiate pricing based on price elasticity and connectivity improvements; maximize revenue from long-term lease agreements, price port dues competitively; critically consider differentiation of charges based on environmental performance; and finally use incentives to align interests of terminal operators and shipping lines. We conclude that the ecosystem perspective is central to the understanding of pricing decisions of port authorities and that various pricing issues deserve more attention.     

A review of port devolution and governance models with compound eyes approach

Port devolution and port governance are focal issues in port studies. This paper argues that the previous typology of port devolution and port governance, including port function matrix models, might have to be modified, in particular for Asian port cases, because they have not considered socio, economic, and political systems and historical aspects behind the port devolution continuum. This paper uses the “compound eyes” approach comprising of many similar, closely-packed facets called ommatidia, with a multiple angle view, to revisit and review previous port devolution and governance models. The paper aims to identify the limitations and rectify fallacies in previous port studies by conducting a critical review and taking a couple of Asian container port cases as examples. This paper contributes to the literature of port devolution and governance, illuminating crucial gaps that the previous studies have not addressed.     

Design-Manufacture Interface Relationship Management in Supply Chain

As firms come under greater market pressure, the management of the inter-functional design/manufacture relationship becomes a more important competitive variable. The characteristics of the design-manufacture interface were analyzed, and several methods of the design-manufacture interface relationship management were compared. Based on theories concerned and enterprise practice, how to manage the relationship of design-manufacture interface to reduce the product cost and shorten the time-to-market was demonstrated, finally the competitive advantage was improved.     

2010美国市场新车技术预览（下）

本文译自美国《MOTOR》杂志。上期介绍了美国国内汽车制造厂2010年推出的新款车型,本期将介绍国外汽车厂家2010年推向美国市场的主要新款车。     

基于模糊逻辑的车辆侧偏角估计方法

提出了一种基于模糊逻辑的汽车侧偏角估计方法。它利用模糊逻辑和汽车运动学模型,将汽车转向盘转角、车轮转速、汽车加速度和横摆角速度信息相融合,进行车辆侧偏角估计。试验结果显示,该方法的鲁棒性和精确性较好,而且响应频率较高,可以满足ESP的控制需要。     

A practical method to estimate the benefits of improved road network reliability: an application to departing air passengers

This paper develops and applies a practical method to estimate the benefits of improved reliability of road networks. We present a general methodology to estimate the scheduling costs due to travel time variability for car travel. In contrast to existing practical methods, we explicitly consider the effect of travel time variability on departure time choices. We focus on situations when only mean delays are known, which is typically the case when standard transport models are used. We first show how travel time variability can be predicted from mean delays. We then estimate the scheduling costs of travellers, taking into account their optimal departure time choice given the estimated travel time variability. We illustrate the methodology for air passengers traveling by car to Amsterdam Schiphol Airport. We find that on average planned improvements in network reliability only lead to a small reduction in access costs per trip in absolute terms, mainly because most air passengers drive to the airport outside peak hours, when travel time variability tends to be low. However, in relative terms the reduction in access costs due to the improvements in network reliability is substantial. In our case we find that for every 1 Euro reduction in travel time costs, there is an additional cost reduction of 0.7 Euro due to lower travel time variability, and hence lower scheduling costs. Ignoring the benefits from improved reliability may therefore lead to a severe underestimation of the total benefits of infrastructure improvements.     

中文文字的计算

中文文字是世界上最古老、使用最广泛的文字，语义丰富，而且可与计算机完美地结合．文字计算可以也应该应用中文文字，以便获得更广泛的应用价值．模糊逻辑为中文文字的形式化提供了一种有效的方法．现在是开展中文文字计算研究的大好时机，并能为投资者提供巨大商机．     

Optimizing the transportation of international container cargoes in Korea

This paper considers a multimodal transportation problem, which is the problem of determining the transportation flow, i.e. volume of container cargoes, and the transportation mode in each trade route, for the objective of minimizing the sum of shipping and inland transportation costs. The problem takes account of two restrictions: maximum cargo volumes capacitated at each seaport and maximum number of vehicles available at each transportation mode. To solve optimally the problem, this paper employs a mixed integer programming, which is an operations research technique. A case study is performed on the container cargo data in Korea and we draw several implications to improve efficiency in the transportation of international trade cargoes in Korea.     

自动化实时监测系统在中国台湾高速铁路浅埋隧道的应用

中国台湾高速铁路新竹二高隧道以覆土深度9～12m穿越台湾北部第二高速公路。为了考虑高速公路下方隧道穿越施工时的行车安全,采用自动化监测系统,监控隧道施工产生之顶部路面沉降与隧道侧墙土层之变位。监测系统采用捷仪工程科技公司GeoAuto自动化实时监测软件系统,该系统分前端、中端、后端三部分。前端部分在隧道顶部沿隧道方向安装有自动量测水平倾斜计、在隧道两侧各安装有自动量测垂直倾斜计与伸张仪,另沿高速公路方向安装3排路面沉降点以全站仪自动监测,前述各类仪器皆连接至资料集录器;中端部分为ADSL、直接联机与无线传输等方式进行数据传输;后端部分为GeoAuto自动监测软件系统,所有路面沉降、土层变位等现场数据,皆由前端仪器量测、经中端传输,最后将所有现场有关沉降、变位等数据,皆显现于后端电脑显示器上。在自动监测系统配合下,有效协助浅埋隧道凿进,顺利完成隧道施工。