The Dublin transportation study

This article deals with the Transportation Study currently nearing completion in Dublin. A feature of this Study was the use of simplified data collection and modelling techniques. Beginning with a brief outline of the background to the transportation problem in Dublin, the article goes on to outline the objectives of the Study and the methods by which these objectives were fulfilled. These methods involved the taking of detailed inventories of Dublin's travel patterns, of its land uses, population and employment, and of its road and public transport systems. Mathematical models were then developed and modified until they could simulate the existing travel patterns to an acceptable degree of accuracy. These models covered the Study's trip generation, modal split, trip distribution and trip assignment stages, and the forms taken by the models are dealt with in the article. The article ends with a summary of the main recommendations of the Dublin Transportation Study.     

Planning for pedestrian networks in North American downtowns

While North American urban regions are served by mechanical modes of transportation, downtowns are largely pedestrian environments. The growth and consolidation of office districts over the last twenty years have revived interest in developing coherent and efficient pedestrian networks, which can be coordinated with other transportation needs within the downtown. Ambitious plans for expansion of the downtown for offices, the retail and service industries as well as for housing and entertainment have been adopted in many North American cities during the 1980s. The successful integration of these large central areas depends to a considerable extent on the implementation of expanded pedestrian networks. This paper discusses certain spatial characteristics of North American cities which call for specific network designs and research into the walking environments of central areas. More knowledge is needed of the relative contributions to pedestrian regeneration of land use combinations, the design of networks and of walking paths.     

Effects of Model Complexity on the Performance of Automated Vehicle Steering Controllers: Model Development, Validation and Comparison

Recent research on autonomous highway vehicles has begun to focus on lateral control strategies. The initial work has focused on vehicle control during low-g maneuvers at constant vehicle speed, typical of lane merging and normal highway driving. In this paper, and its companion paper, to follow, the lateral control of vehicles during high-g emergency maneuvers is addressed. Models of the vehicle dynamics are developed, showing the accuracy of the different models under low and high-g conditions. Specifically, body roll, tire and drive-train dynamics, tire force saturation, and tire side force lag are shown to be important effects to include in models for emergency maneuvers. Current controllers, designed for low-g maneuvers only, neglect these effects. The follow on paper demonstrates the performance of lateral controllers during high-g lateral emergency maneuvers using these vehicle models.     

Choosing the wrong technology: Or how to spend billions and reduce transit use

In spite of a broad consensus among transportation analysts that bus rapid transit, whether operating on exclusive rights-of-way or on uncongested high occupancy vehicle lanes or general purpose limited access facilities, provides higher performance and has significantly lower costs per passenger trip than rail transit in medium and low density cities, nearly all Sunbelt cities are building or planning heavy or light rail systems. This paper reviews previous studies of the cost-effectiveness of heavy and light rail transit with bus-rapid transit and the growing experience with busways and transitways and concludes, once again, that some form of bus rapid transit would be a far more effective way of providing improved transit in these cities than heavy or light rail transit. Not only would bus rapid transit be substantially cheaper, but it would provide a higher quality of service than light or heavy rail transit for virtually all users. Finally, the paper speculates on the reasons for the continued, “blind” commitment to rail transit by policymakers in Sunbelt cities and on the refusal of policymakers in all but a few of these cities to even consider bus rapid transit.     

The national role in world port development: United States and Western Europe

This paper gives a review of port policies of Western European countries and of the USA, and contrasts the roles of the ports of individual countries. Following a discussion on the assessment of port performance, the paper concludes with remarks on principles of port policy and the implications of Western European policies on US port policy.     

微生物封堵技术(Bio-Sealing)用于隧道防水

荷兰国家岩土工程研究所(GeoDelft)近来提出了一个称为SmartSoils的新概念.Smart Soils,意即人们所需要的土,其着眼点在于土的某些性质(如渗水性、刚度和强度),以及如何将它们改良,使之能满足工程建设的某些要求.这些新的技术在岩土工程中可以被广泛应用.     

最棒的配件供应商们如何利用简洁的商业流程取得财务上的显著变革

“现在是预算季——是时候专注于下一年的预算了!”听上去是不是很耳熟？作为向传统的成百供应商提供服务的CSM现在每天都能听到这些。然而，一些前沿的供应商正在将他们的财务预算转变为实时的决策性武器。他们扩充了五年计划，不仅包含了成交量和应纳税收，还有现在和将来所有方面的开支。同时，他们的商业机构在报价、成本计算、和预测方面有惊人的速度。这些提高使实时预算计划不受上级的管理。这些公司有能力来提取六年利润和产品、厂方、客户方的损失信息，并快速作出决策。[编者按]     

Robust state feedback stabilization of articulated steer vehicles

In this work, a full-state feedback controller is designed to prevent the oscillatory instability or snaking behaviour of an articulated steer vehicle. To design the controller, first, a linearized model of the vehicle is developed and analyzed to identify the most important uncertain tire parameters with regard to the snaking mode. By using this linearized model, the equations of motion are represented in the form of a polytopic system, which depends affinely on the most important uncertain tire parameters. Then, by solving some linear matrix inequalities, both the Lyapunov and state feedback matrices for the robust stabilization of the vehicle are found. The performance of the resulting controller is evaluated by conducting several simulations based on the linearized model. To verify the results from the linearized model analysis, some simulations are also done by a virtual prototype of the vehicle in ADAMS. The results based on the linearized model are reasonably consistent with those from the simulations in ADAMS. They show that the controller can effectively stabilize the vehicle during the snaking mode in different driving conditions.     

Low-fi simulation of bridge team communication

The paper compares the pedagogical advantages of two simulation types used for training verbal maritime communication. It tests the hypothesis that “low-fi” simulation using online web conference software, specifically ‘chat’ or messaging, is a valid complementary tool for the instruction of Maritime English and full-mission simulation. Based on a series of exercises involving multi-national and multi-lingual students, various linguistic patterns are determined and compared to audio recordings of full-mission simulation. Probability of superiority effect sizes is computed to quantify the observed effects. The findings corroborate the proximity of language patterns found in low-fi and full-mission simulation. Pedagogical implications are discussed, and future research possibilities are outlined.