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31.
The paper demonstrates a method to determine road network improvements that also involve the use of a road toll charge, taking the perspective of the government or authority. A general discrete network design problem with a road toll pricing scheme, to minimize the total travel time under a budget constraint, is proposed. This approach is taken in order to determine the appropriate level of road toll pricing whilst simultaneously addressing the need for capacity. The proposed approach is formulated as a bi-level programming problem. The optimal road capacity improvement and toll level scheme is investigated with respect to the available budget levels and toll revenues. 相似文献
32.
Laurie A. Garrow Susan Hotle Stacey Mumbower 《Transportation Research Part A: Policy and Practice》2012,46(2):255-268
This paper reviews product debundling trends that have occurred in the US airline industry. Multiple sources of ancillary fees related to ticketing refunds and exchanges, checked baggage, on-board pets, preferred and/or advanced seating assignments, frequent flyer ticket redemptions, and day of departure standby policies are reviewed. Despite the fact that both low cost and network carriers stress the importance of future ancillary fees in their investor reports, our assessment suggests that these fees will be more broadly adopted by low cost carriers. We anticipate that many network carriers will eliminate ancillary fees, particularly as they begin to recognize how these fees can impact other system performance objectives such as minimizing the number of misconnecting passengers. We estimate that the debundling phenomenon has diluted revenues to the US Airport and Airways Trust Fund by at least 5%. 相似文献
33.
Transportation - Previous research has demonstrated the relevance of life events to explain changes in travel behavior. Less clear is the moderating role played by life stages on the relationship... 相似文献
34.
Z. Shi I. Legate F. Gu J. Fieldhouse A. Ball 《International Journal of Automotive Technology》2010,11(3):363-373
An Antilock Braking System (ABS) is one of the most important safety facilities equipped in modern vehicles. A self-test is
therefore embedded into its ECU to identify any electronic malfunction. However there is no effective method to predict or
check its mechanical conditions routinely to ensure its functionality. Because the ABS system is merely actuated above a particular
speed in emergency stops, the current brake test facilities are not adequate for ABS test. Because of the dangers involved
it would not be acceptable to use a public road to implement such a practice for fault detection so an alternative means must
be sought. To provide a safe and convenient solution this paper proposes a novel method to predict ABS faults whilst the vehicle
is stationary. In this situation a model-based approach is applied to predict various faults from the ABS, especially from
its hydraulic subsystem. As such, a mathematic model is developed to describe the operating processes of ABS including possible
faulty conditions. An autonomous control strategy is also designed to actuate the control module independently without the
knowledge of the control algorithms embedded in an ABS control module. This approach is evaluated through a Simulink simulation. 相似文献
35.
Montira WatcharasukarnShannon Page Susan Krumdieck 《Transportation Research Part A: Policy and Practice》2012,46(2):348-367
The peak and decline of world oil production is an emerging issue for transportation and urban planners. Peak oil from an energy perspective means that there will be progressively less fuel. Our work treats changes in oil supply as a risk to transport activity systems. A virtual reality survey method, based on the sim game concept, has been developed to audit the participant’s normal weekly travel activity, and to explore participant’s travel adaptive capacity. The travel adaptive capacity assessment (TACA) Sim survey uses avatars, Google Map™, 2D scenes, interactive screens and feedback scores. Travel adaptive capacity is proposed as a measure of long-range resilience of activity systems to fuel supply decline. Mode adaptive potential is proposed as an indicator of the future demand growth for less energy intensive travel. Both adaptation indicators can be used for peak oil vulnerability assessment. A case study was conducted involving 90 participants in Christchurch New Zealand. All of the participants were students, general staff or academics at the University of Canterbury. The adaptive capacity was assessed by both simulated extreme fuel price shock and by asking, “do you have an alternative mode?” without price pressure. The travel adaptive capacity in number of kilometers was 75% under a 5-fold fuel price increase. The mode adaptive potential was 33% cycling, 21% walking and 22% bus. Academics had adaptive capacity of only 1-5% of trips by canceling or carrying out their activity from home compared to 10-18% for students. 相似文献
36.
Gina Elliott Bruce Mitchell Bonnie Wiltshire Ir. Abdul Manan Susan Wismer 《Coastal management》2013,41(4):295-316
Coral reef areas are threatened worldwide by growing populations, tourism development, and use of poison and dynamite in fishing in areas adjacent to the reefs. The designation of marine protected areas is one strategy for addressing these problems. Wakatobi National Park, established in Eastern Indonesia in 1996, contains approximately 50,000 ha of coral reefs and a resident population of Sama-Bajo people whose traditions and current livelihoods tie them closely to the sea. The present research, using participatory rural appraisal methods, focused upon the impact of the designation of the Marine Park on their lives and investigated the potential for public participation in park planning and management. The Wakatobi Park Management Plan does not address the needs and interests of local people. Priority should be placed on adaptation of park zoning and protection regulations to accommodate the livelihood requirements of indigenous communities. 相似文献
37.
Despite the emphasis placed on the contextual nature of integrated coastal management (ICM) implementation in the literature, many uniformities are encountered in ICM implementation worldwide. In this article the tangled threads of ICM practice are unravelled and a theoretically founded set of criteria for evaluating the design of ICM implementation models is provided. First, paradigms in integrated environmental management (IEM) implementation, the broader domain within which ICM practice is nested, are characterized in terms of their key concepts. Next, the paradigms are used as a mechanism to distill uniformities in ICM practice as reported in review articles. Finally a set of fourteen building blocks against which the scientific credibility of contextual, country-specific ICM implementation models can be validated, is generated by translating the theory-based characterization into evaluation criteria readily accessible to practitioners. 相似文献
38.
Transportation - Suburban development in the US is widely criticized for its contribution to automobile dependence and its consequences. Not surprisingly, then, a return to more urban-style... 相似文献
39.
Most EU member states and the European Commission regard the PPP as an important tool to attract additional financial resources for high priority investments such as transport. The objective of this paper is to delineate the EU panorama of PPP markets and investigate the impacts of EU institutions in the development and success of this type of financial arrangement for the transport sector in Europe. We examine how the scope of the PPP in Europe is based on the flexibility and adaptability of the contract to the features of the project and to the economic and institutional environment. These issues are illustrated through a number of examples in the transport sector. We conclude by observing that the market for PPPs, although still fragmented nationally, is developing a European dimension and attracting resources from a variety of players. 相似文献
40.
The undrained bearing capacity of a spudcan foundation under combined loading in soft clay 总被引:1,自引:0,他引:1
Mobile jack-up drilling rigs are typically supported by individual, large diameter spudcan foundations. Before deployment, the suitability of a jack-up to a location must be shown in a site-specific assessment under loads associated with a 50-year return period storm, which ultimately need to be resisted by the foundations. The capacity of the spudcans under combined vertical, horizontal and moment loading is therefore integral to the overall site-specific assessment of the jack-up.In soft clays, spudcans can penetrate deeply into the seabed, sometimes up to several footing diameters, with soil flowing around the downward penetrating footing, sealing the cavity. Although this is generally believed to provide some additional bearing capacity to the footing, no detailed study or formal guidance is available to date. This study, therefore, investigates the influence of soil back-flow on the failure mechanisms and quantifies the effect on the capacity of a spudcan under general loading through finite element analyses. A closed-form analytical expression is developed that describes the capacity envelope under combined loading, applicable to embedment depths ranging from shallow to deep. 相似文献