Selection of expert system shells for traffic signal design

Although the use of expert systems (ESs) as a problem-solving tool is relatively new in the transportation profession, it has been recognized that a well-designed ES can contribute in areas where the knowledge domain requires an integration of expertise from various disciplines or is very complex and difficult to quantify. To minimize the effort involved in developing essential ES mechanisms, researchers often prefer to use ES shells which provide a standard inference procedure, knowledge representation, and a user-friendly design environment. However, commercial ES shells tend to be designed for only certain classes of problems, and are not as general and flexible as programming languages. More than 150 commercial ES shells are available in the microcomputer market. Most ES shells are usually claimed by their vendors to be usable for almost any conceivable applications, but such claims have often proved to be extravagant. Hence, the selection of an efficient yet costeffective commercial shell is one of the most critical tasks in ES development. In reviewing the vital task of ES shell selection, this paper presents our experience in evaluating more than 30 ES shells for developing an ES for signal design. The proposed ES includes signal settings, phasing plans, controllers, and detector locations.     

A three-phase QFD-based framework for identifying key passenger needs to improve satisfaction with the seat of high-speed rail in China

This study aims to suggest a three-phased methodological framework based on the operational approach of quality function deployment (QFD) to improve the service quality and passenger satisfaction with China’s high-speed rail (HSR) by identifying the key passenger needs with regard the HSR seats. For the first phase, the collection of the voice of the customers/passengers (VOC), the processing of the collected VOC into need items and further into passenger needs of QFD would be explained in terms of knowledge management. For the second phase, a reference comparison-based fuzzy best–worst method is developed for determining the relative importance of passenger needs, with a particular purpose of coping with the uncertainty and ambiguity associated with qualitative assessment of respondents. For the third phase, the importance-performance analysis is performed to determine the improvement priorities for meeting passenger needs. Findings showed that Body-friendly seat structure and Reasonable layout of the seat are the two most important needs demanded by the passengers of second-class cabins, with the former being the top priority. The current study provides useful references for service operators of HSR to formulate development strategies for improving the seat comfortability, which subsequently contributes to improving HSR’s service quality and passenger satisfaction. Moreover, the proposed methodological framework for identifying the important passenger needs can be appropriately adjusted and expanded to similar transportation infrastructures and facilities.

     

Pedestrian streets in Singapore

A fair amount of literature pertaining to pedestrian streets has been produced but for the most part it is on the American and European developments. There has been surprisingly little published research on pedestrian street development in Asia. The purpose of this paper, therefore, is to examine pedestrian streets in Asia, using the city-state of Singapore as a case study. Since the mid-1980s, pedestrian streets have been adopted as a policy in the conservation and planning of Singapore's city centre. The resulting pedestrian streets came in many forms, from a single pedestrian-only street to a whole precinct of several streets.     

Impact of politics,economic events and port policies on the evolution of maritime traffic in Chinese ports

The Chinese government has been exploring various paths to find a direction that better suits China’s national conditions during the past 60 years. Meanwhile, a series of political and economic events and policy transformations have had different effects on the port industry. This article attempts to ascertain how these events and port policies have influenced Chinese port traffic through an empirical study on data covering 1952–2009. The findings suggest that foreign trade has been the prime driver of the throughput of Chinese ports. The increase in the ports’ throughput has enabled an increase in domestic demand and the urgent need for further port investment. Chinese port throughput has been subject to multiple shocks. The Great Leap Forward¹ is found to have had the largest, but only a short-term impact. China’s accession to the World Trade Organization, however, led to a longer and exclusive effect on ports, with little observed effect on the other variables. The reform of port governance is shown to have had a more lasting positive effect on port throughput than physical investment. However, these latter effects are minor, the economic and political factors remain the primary driving factors of port throughput.     

Evaluating Key Resources and Capabilities for Liner Shipping Services

Abstract

This paper empirically evaluates key resources and capabilities in the liner shipping context. Based on a factor analysis, three resource dimensions are identified: marine equipment, information equipment, and corporate image; whereas seven capability dimensions are identified: purchasing, operation, human resource management, customer service, information integration, pricing, and financial management. The findings suggest that operation capability is perceived as the most important dimension, followed by customer service, human resource management, information integration, pricing purchasing, and financial management. Results indicate that four dimensions are found that significantly differ between shipping companies and agencies: marine equipment, information equipment, operation, and information integration. The theoretical and managerial implications of the research findings are discussed.     

用于海底ROV在强流干扰下的一种自适应防走滑装置（英文）

This paper proposed a new concept of an adaptable multi-legged skid design for retro-fitting to a remotely-operated vehicle(ROV) during high tidal current underwater pipeline inspection. The sole reliance on propeller-driven propulsion for ROV is replaced with a proposed low cost biomimetic solution in the form of an attachable hexapod walking skid. The advantage of this adaptable walking skid is the high stability in positioning and endurances to strong current on the seabed environment. The computer simulation flow studies using Solidworks Flow Simulation shown that the skid attachment in different compensation postures caused at least four times increase in overall drag, and negative lift forces on the seabed ROV to achieve a better maneuvering and station keeping under the high current condition(from 0.5 m/s to 5.0 m/s). A graphical user interface is designed to interact with the user during robot-in-the-loop testing and kinematics simulation in the pool.     

复杂形体远程操控水下运载器水动力阻尼模型建模和检验(英文)

In this paper,numerical modeling and model testing of a complex-shaped remotely-operated vehicle(ROV) were shown.The paper emphasized the systematic modeling of hydrodynamic damping using the computational fluid dynamic software ANSYS-CFXTM on the complex-shaped ROV,a practice that is not commonly applied.For initial design and prototype testing during the developmental stage,small-scale testing using a free-decaying experiment was used to verify the theoretical models obtained from ANSYS-CFXTM.Simulation results are shown to coincide with the experimental tests.The proposed method could determine the hydrodynamic damping coefficients of the ROV.     

中国南海ASDD深水试验井中的锚泊设计与作业(英文)

Mooring systems play an important role for semi-submersible rigs that drill in deepwater.A detailed analysis was carried out on the mooring of a semi-submersible rig that conducted a trial well drilling at a deepwater location in the South China Sea in 2009.The rig was 30 years old and had a shallow platform with a designed maximum operating water depth of 457 m.Following the mooring analysis,a mooring design was given that requires upgrading of the rig’s original mooring system.The upgrade included several innovations,such as installing eight larger anchors,i.e.replacing the original anchors and inserting an additional 600 m of steel wires with the existing chains.All this was done to enhance the mooring capability of the rig in order for the rig to be held in position to conduct drilling at a water depth of 476 m.The overall duration of the drilling was 50 days and the upgraded mooring system proved to be efficient in achieving the goal of keeping the rig stationary while it was drilling the trial well in the South China Sea.This successful campaign demonstrates that an older semi-submersible rig can take on drilling in deep water after careful design and proper upgrading and modification to the original mooring system.