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851.
Abstract The legal battles employed as a strategy to secure increased environmental safeguards identified by the technical studies demonstrate the role of public opinion in shaping federal actions. This article approaches the question of risk from OCS oil production activities by discussing the methodology developed to identify the probability of impact to the south shore of Long Island from the potential of an oil spill, either from drilling or transport activities. A set of probability curves were developed in accordance with seasonal climatic and current patterns in order to establish a range of hazard zones to enable the development of regulatory policy for the location and relocation of shipping lanes that would minimize direct impact to the near shore waters and coastline of Long Island. 相似文献
852.
Singapore's Land Transport Authority, formed in 1995, set itself a mission of producing a world class transport system. This paper assesses the extent to which this goal is being achieved. It outlines the structure within which transport decisions are taken and indicates the freedom this gives to develop integrated transport and land‐use strategies. It demonstrates the long‐term stability in transport strategy from 1972 onwards, and the key contributions to that strategy of land‐use controls and travel‐demand management measures. The individual elements of the strategy are then reviewed and innovations identified in demand management, public transport service provision and information technology. Finally, the key attributes that have led to the success of the strategy are identified, and it is suggested that many of these are transferable to other cities of the developed world. 相似文献
853.
Management of enterprises in the public domain are being asked to look beyond financial measures of performance towards a system of performance indicators which will reflect achievement in quantitative but not necessarily monetary terms. The essential element of this approach is the role that management must play in the selection of indicators which reflect key dimensions of performance and objectives of the organization. This paper identifies comparison and presentation methods which are likely to be of practical help to managers facing the tasks of control and communication in the wider accountability process. The issues raised are illustrated in a case study derived from an analysis of road maintenance management data from New Zealand territorial local authorities 1982–87. 相似文献
854.
Sang Hyup Lee 《运输规划与技术》2013,36(5):361-375
If we are to accommodate the rate of urban growth which North America will face in the first half of the twenty-first century, it is the contention of this paper that we must build new cities, not new towns, beyond commuting distance of existing cities. These can be located in open countryside on virgin land, or they can grow around existing small towns, all in conjunction with the construction of an innovative personal transportation system. In this paper a hexagonal modular structure, in which self-contained urban units can be combined and added to over time, is proposed as a new urban form and AVCS maglev — which will serve the new cities efficiently — is proposed as a key transportation strategy. 相似文献
855.
Transport projects involve costs and benefits. Benefits to users appear in the form of more and/or better trips. Once the neoclassical idea of demand is accepted, the variation of utility levels underlie the measurement of benefits. In the evaluation process, benefits have to be compared with costs, and this can be done converting utility into monetary units. This paper deals with the treatment of this problem, starting with the general relation among utility, demand and the various forms of consumers’ surplus, to move further into the particular forms that these relations take in the transport field. The rule‐of‐a‐half is followed from the intuitive initial justification to a strict (and general) analytical derivation. More rigorous forms of users’ surplus variation are then presented for fairly general cases, including both aggregate and disaggregate transport demand models, emphasizing the manner in which welfare measures are derived in each case. Discussion is centred around the comparative advantages and limitations of available approaches, searching for improvements in demand formulation and benefits measurement. 相似文献
856.
J.L. Sullivan D.C. Novak L. Aultman-Hall D.M. Scott 《Transportation Research Part A: Policy and Practice》2010,44(5):323-336
A wide range of relatively short-term disruptive events such as partial flooding, visibility reductions, traction hazards due to weather, and pavement deterioration occur on transportation networks on a daily basis. Despite being relatively minor when compared to catastrophes, these events still have profound impacts on traffic flow. To date there has been very little distinction drawn between different types of network-disruption studies and how the methodological approaches used in those studies differ depending on the specific research objectives and on the disruption scenarios being modeled.In this paper, we advance a methodological approach that employs different link-based capacity-disruption values for identifying and ranking the most critical links and quantifying network robustness in a transportation network. We demonstrate how an ideal capacity-disruption range can be objectively determined for a particular network and introduce a scalable system-wide performance measure, called the Network Trip Robustness (NTR) that can be used to directly compare networks of different sizes, topologies, and connectivity levels.Our approach yields results that are independent of the degree of connectivity and can be used to evaluate robustness on networks with isolating links. We show that system-wide travel-times and the rank-ordering of the most critical links in a network can vary dramatically based on both the capacity-disruption level and on the overall connectivity of the network. We further show that the relationships between network robustness, the capacity-disruption level used for modeling, and network connectivity are non-linear and not necessarily intuitive. We discuss our findings with respect to Braess’ Paradox. 相似文献
857.
H. Yamaguchi S.-I. Doi N. Iwama Y. Hayashi 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(5):299-308
The improvements of ride comfort and vehicle maneuverability in the vehicle design can be achieved by using an active suspension. However, the problems in such a control are the complex control logic because of the control laws incompatible with the improvements of ride comfort and maneuverability, and the cost increase because of various sensors to be attached. Therefore, we examined the control abilities of ride comfort and maneuverability on a unique control law using frequency shaped LQ, and controlled the characteristic of the contact between tire and road without a road displacement sensor 相似文献
858.
在车辆修理的总费用中,轮对维修的费用-般会占到30%.轮对维修的费用主要发生在用于车轮镟修和轮对的更换上.尽管材料因素限制了车轮的使用寿命早已成为共识,但到目前为止,在采用新型材料以显著提高车轮寿命方面并没有太大的进展. 相似文献
859.
Evaluation of automotive forward collision warning and collision avoidance algorithms 总被引:2,自引:0,他引:2
K. Lee H. Peng 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(10):735-751
Collision warning/collision avoidance (CW/CA) systems target a major crash type and their development is a major thrust of the Intelligent Vehicle Initiative. They are a natural extension of adaptive cruise control systems already available on many car models. Many CW/CA algorithms have recently been proposed but the existing literature mainly focuses on algorithm development. Evaluations of these algorithms have been usually based on subjective ratings. The main contribution of this paper is the utilization of a naturalistic driving data set for the evaluation of CW/CA algorithms. We first collect manual driving data from the ICCFOT project, then process the data by Kalman smoothing, and finally identify 'threatening' and 'safe' data sets according to vehicle brake inputs and vehicle range behavior. Five CW/CA algorithms published in the literature are evaluated against the identified data sets. The performance of these algorithms is determined through a performance metric commonly used in signal detection and information retrieval under unbalanced data population. 相似文献
860.
Sri Lanka observes 100 years of bus passenger transport in 2007. During this period the country has seen different forms of service providers ranging from private sector monopolies to state sector monopolies. It also has seen several changes in state policy ranging from welfare orientated service provision to entire market determined without any regulation. The existing regulated mixed competition is also characterized by poorly equipped regulators. In conclusion, the paper traces the different stages of failure that have led to the poor quality of bus transport services existing at present. 相似文献