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1.
This study investigates the economic incentive-drivers used in various configurations in green supply chains. The configurations of competitive suppliers and integrated transportation are studied for recycled materials with low economic value but high environmental impact. Arguments are embodied in a competitive game that manifests interactions among competing manufacturers, suppliers of virgin materials, suppliers of recycled materials, and the government. Because of market size and technology limitation, long hauling to few remote treatment facilities is observed in practice. Demand-dependent transportation efficiency arisen from economies of scale thus affects the equilibrium states in the game of this recycling system. Managerial insights are provided to encourage the use of low-value recycled materials. A tax-subsidy system is conditionally effective when using recycled materials maintains quality. When quality becomes compromised by mixing recycled materials, we find that integrating suppliers of recycled materials with those of virgin materials can make the tax-subsidy system effective again.  相似文献   

2.
The purpose of this paper is to provide an introduction to the nature and purpose of airport automated people mover (APM) systems. Our objective is to provide a convenient research tool for persons seeking an introduction to the airport APM industry. Included are illustrations of typical system designs; a listing of existing airport APM systems, including a tabular presentation of selected data; an organization and discussion of the history and evolution of the existing systems; and a status report on current developments in the APM industry.  相似文献   

3.
近年来,随着桥梁建设事业的飞速发展,桥梁结构的使用荷载日益增大,大批既有桥梁结构也进入了老化期,桥梁检测与加固由此越发显得重要。 多年来,西部交通建设科技项目管理中心进行了大量桥梁检测评定与加固技术的研究,所取得的系列成果及积累的经验表明:公路旧桥检测评定与加固技术的研究及推广不仅对规范公路旧桥加固改造市场、提升旧桥加固技术水平和质量品质是十分必要的,而且具有可观的经济效益和社会效应。本篇针对西部地区在桥梁检测与加固技术研究方面取得的部分成果进行介绍,以期推广应用。  相似文献   

4.
Theory suggests that profit maximizing firms have an incentive to incorporate cost-effective technologies into their products. However, simple net present value calculations comparing upfront costs of fuel-saving technologies to future savings suggest this is not always the case. This puzzle is commonly referred to as the “energy efficiency paradox.” A growing number of empirical studies examine why households may under-invest in energy efficiency. Fewer studies examine similar undervaluation by businesses. We explore investment decisions within the heavy-duty trucking sector for fuel-saving technologies via focus groups and interviews to gain insight into what factors might explain apparent underinvestment in fuel-saving technologies. We find some evidence that market failures related to lack of information about technology performance and network externalities contribute to slow adoption of some technologies. However, information about new technologies for tractors seems to generate limited spillovers. There is also some evidence of split incentives between owners and drivers, though companies have invested in a variety of technologies and approaches in an attempt to address these effects. Other factors important in trucking investment decisions that are not classic market failures include tradeoffs between fuel economy and other valued truck attributes, as well as uncertainty and risk associated with new technologies if decision-makers are loss averse.  相似文献   

5.
An information system is presented which identifies the transportation technologies suited to any one transportation need situation lying in a broad range of such situations. The system is concerned with people movement rather than goods movement. The user of the system specifies the nature and extent of demand, as well as certain service requirements. A transportation technology is identified as suited to a particular need situation when the technology meets the demand and the service requirements, and does so at reasonable cost. The technologies identified by the system as suited to a need situation must be examined to select the one best alternative. This final selection process is not part of the system. This system consists of two tables. Their use is described and examples are given. The procedure used to develop the tables is discussed. The system identifies new transportation technologies (PRT, AGT, etc.) as well as old.  相似文献   

6.
VAL (Light Automated Vehicle) is a medium capacity driverless automated guideway transit system. It has demonstrated both technical feasibility and economical performance of driverless operation applied to a metro line. It includes several advanced well proven technologies. Since the first line design, the product has been adapted to various operating requirements and enhanced by application of further technological evolutions in several areas: Automatic Train Control, Rolling Stock, Track.  相似文献   

7.
Current car technologies will not solve upcoming challenges of mitigating greenhouse gas emissions in road transport. Projections of the market penetration by alternative drive train technologies are controversial regarding both forecast market shares and applied scientific methods. Accepting this latter challenge, we provide a (so far missing) overview of methods applied in this field and give some recommendations for further work. Our focus is to classify the applied methods into a convenient pattern and to analyse models from the recent scientific literature which consider the electrification of light-duty vehicles. We differentiate the following bottom-up approaches: Econometric models with disaggregated data (such as discrete choice), and agent-based simulation models. The group of top-down models are subdivided into econometric models with aggregated data (e.g. vehicle stock data), system dynamics, as well as integrated assessment models with general equilibrium models. It becomes obvious that some methods have a stronger methodological background whereas others require comprehensive data sets or can be combined more flexibly with other methods. Even though there is no dominant method, we can identify a trend in the literature towards data-driven hybrid approaches, which considers micro and macro aspects influencing the market penetration of electric vehicles.  相似文献   

8.
Procurement of an Automated Guideway Transit (AGT) system is a relatively new process for many procuring agencies worldwide. Outside of large airports, no single transit market sector has enough experience to establish well proven procurement methodologies for innovative transit technologies. Several methods, however, have emerged recently which, together with more conventional approaches, make the decision making process quite complex. The objective of this article is to review currently used and recently considered procurement methods and recommend a methodology for their selection depending on specific project requirements.  相似文献   

9.
通过对高速针对常规清障车由于超高、转弯空间受限无法进入地下车库进行施救的难题,文章提出了专用皮卡式清障车的总体功能要求,探讨了总体布置、底盘选型与改造、专用装置结构设计等关键技术,研发并制造了皮卡式清障车样机,并进行了相应功能验证。在此基础上,深入剖析了皮卡式清障车在市场应用中所遇到的问题,并提倡将"主动救援新模式"常态化。  相似文献   

10.
One full year of high-resolution driving data from 484 instrumented gasoline vehicles in the US is used to analyze daily driving patterns, and from those infer the range requirements of electric vehicles (EVs). We conservatively assume that EV drivers would not change their current gasoline-fueled driving patterns and that they would charge only once daily, typically at home overnight. Next, the market is segmented into those drivers for whom a limited-range vehicle would meet every day’s range need, and those who could meet their daily range need only if they make adaptations on some days. Adaptations, for example, could mean they have to either recharge during the day, borrow a liquid-fueled vehicle, or save some errands for the subsequent day. From this analysis, with the stated assumptions, we infer the potential market share for limited-range vehicles. For example, we find that 9% of the vehicles in the sample never exceeded 100 miles in one day, and 21% never exceeded 150 miles in one day. These drivers presumably could substitute a limited-range vehicle, like electric vehicles now on the market, for their current gasoline vehicle without any adaptation in their driving at all. For drivers who are willing to make adaptations on 2 days a year, the same 100 mile range EV would meet the needs of 17% of drivers, and if they are willing to adapt every other month (six times a year), it would work for 32% of drivers. Thus, it appears that even modest electric vehicles with today’s limited battery range, if marketed correctly to segments with appropriate driving behavior, comprise a large enough market for substantial vehicle sales. An additional analysis examines driving versus parking by time of day. On the average weekday at 5 pm, only 15% of the vehicles in the sample are on the road; at no time during the year are fewer than 75% of vehicles parked. Also, because the return trip home is widely spread in time, even if all cars plug in and begin charging immediately when they arrive home and park, the increased demand on the electric system is less problematic than prior analyses have suggested.  相似文献   

11.
New technologies in traffic can produce a range of unknown and unplanned deviations which require attention when assessing such technologies for market implementation. Current assessment methods focus on expected and usually desired effects and do not include identification and analyses of all kinds of other effects resulting from processes other than the desired processes. In this paper a method called HAZOP (Hazard and Operability analysis), originally developed for identifying unintended safety problems in chemical processes, is introduced and applied in order to analyse the added value of this method for large scale pilots with intelligent transport systems. The paper discusses the additional potential safety problems which the HAZOP identifies, that should be analysed before implementation of intelligent speed adaptation in daily traffic can be considered.  相似文献   

12.
Rail capacity is currently administratively allocated in Europe, whereas the economic literature has often contemplated the opportunity of introducing market mechanisms, auctions in particular, into this industry. This article tries to fill the gap between practice and theory. It first describes the properties of rail capacity (rigidity and non-homogeneity) and shows that because of its very nature, this capacity must be allocated through combinatorial auctions. As identified by the economic literature, using combinatorial auctions introduces a lot of complexity (winner determination and information burden) into the allocation process. To deal with this complexity, some form of centralized planning is necessary to design the right market mechanisms and to allocate capacity. This could have strong consequences on the current deregulation process.  相似文献   

13.

Most airlines across Asia are struggling to cope with an unprecedented economic crisis which they have very little control over, and the survival of some remains in doubt. The continuing uncertainty generated by the crisis has accelerated the process of change in the aviation industry and has highlighted the need for adaptability, and its effects have been deeper and longer lasting than previously anticipated. After a year-long slump in the Asian travel market, airlines are now considering a range of options and rehabilitation programmes including a series of cost-cutting measures. There appears to be a trend towards the extension and consolidation of strategic alliances, structural and operational reorganization, and the application of new technologies. The success of these measures will become apparent over time, but action is necessary to minimize the adverse consequences of the crisis which has dominated the region since 1997.  相似文献   

14.
ABSTRACT

Connected and autonomous vehicle (CAV) technologies are expected to change driving/vehicle behavior on freeways. This study investigates the impact of CAVs on freeway capacity using a microsimulation tool. A four-lane basic freeway segment is selected as the case study through the Caltrans Performance Measurement System (PeMS). To obtain valid results, various driving behavior parameters are calibrated to the real traffic conditions for human-driven vehicles. In particular, the calibration is conducted using genetic algorithm. A revised Intelligent Driver Model (IDM) is developed and used as the car-following model for CAVs. The simulation is conducted on the basic freeway segment under different penetration rates of CAVs and different freeway speed limits. The results show that with an increase in the market penetration rate, freeway capacity increases, and will increase significantly as the speed limit increases.  相似文献   

15.
This study explores how to facilitate the electric vehicle (EV) diffusion from a two-sided market platform competition. We develop a stylized model depicting the platform competition between electric and gasoline vehicles by combining indirect network effects of consumer and energy supplier sides as well as vehicle manufacturers’ profits. The findings of this study provide several meaningful strategic and policy implications for EV manufacturers and policymakers who wish to enhance EV diffusion. First, EV sales are significantly influenced by indirect network effects from the energy supplier side to the consumer side, and vice versa. This implies that EV manufacturers who wish to boost EV diffusion should implement a strategy providing energy suppliers with incentives to willingly join the EV platform. Second, the dynamic nature of the effects of energy costs on platform competition might render counter-intuitive evidence that the drop in oil prices does not always negatively influence EV sales. This requires EV manufacturers to prepare a contingent strategy adjusting to such unexpected conditions. Third, governments should consider the energy supplier side as well as the consumer side in designing EV diffusion policies. When governments have a very challenging EV diffusion target, a balanced policy, which treats both gasoline and electric vehicle technologies fairly, may be more effective than a consumer subsidy policy.  相似文献   

16.
A generalised model is used to provide estimates of overall trip times and speed for conventional corridor‐collective transport and PRT. The results demonstrate why traditional forms of transport find difficulty providing an effective service in a city. Short separations between stops are required to minimise walk times but on conventional transport this leads to significant reductions in achievable speed because of the need for frequent stops. It is also shown that there is very little benefit in service effectiveness from LRT/APM/Monorail over buses. PRT is immune to these effects. The present calculations typically show a benefit for PRT of a factor of two or greater in trip time over either bus or LRT/APM.  相似文献   

17.
This paper is concerned with the development of an Internet-based geographic information system (GIS) that brings together spatio-temporal data, models and users in a single efficient framework to be used for a wide range of transportation applications – planning, engineering and operational. The functional requirements of the system are outlined taking into consideration the various enabling technologies, such as Internet tools, large-scale databases and distributed computing systems. Implementation issues as well as the necessary models needed to support the system are briefly discussed.  相似文献   

18.
A discussion of the benefits of bus priority schemes shows the importance of providing adequate capacity for all streams of traffic. The analysis of capacity at a signal-controlled road junction is extended to cases where stages may be truncated or omitted in some cycles. The problem of finding signal settings which, when implemented with priority, emulate some which are known to provide a given level of capacity when implemented without priority is considered. Two commonly used rules to give priority by selective vehicle detection are analysed in detail and a third is considered briefly to illustrate the flexibility of the methods used. The range of conditions under which these priority methods can be implemented without causing any loss of capacity is quantified. If an additional rule is implemented to prevent priority from being granted too frequently, then this range covers most practical operating conditions. In cases outside this range, consequent losses of capacity can be estimated. A numerical example based upon a real bus priority experiment is provided.  相似文献   

19.
Plug-in electric vehicles (PEVs) have the potential to reduce green house gas emissions from the transport sector. However, the limited electric range of PEVs could impede their market introduction. Still some potential users are willing to pay more for PEVs. The combined effect of these and other influencing factors as well as the resulting future market evolution are unclear. Here, we study the market evolution of PEVs in Germany until 2020. Our results reveal a great deal of uncertainty in the market evolution of PEVs due to external conditions and the users’ willingness to pay. We find the future share of PEVs in German passenger car stock to range from 0.4% to almost 3% by 2020. Energy prices have a large impact on PEV market evolution as a 25% increase in fuel prices would double the number of PEVs in stock by 2020 compared to a reference scenario. We find a special depreciation allowance for commercial vehicles and a subsidy of 1000 Euro as the most effective and efficient monetary policy options. The high uncertainty of the market evolution implies that policies to foster market diffusion of PEVs should be dynamically adaptable to react to changing framework conditions.  相似文献   

20.
Lighterage contributes significantly to the maritime industry since thousand tons of necessary supplies have to be delivered to mother vessels anchored near sea every day. A single lighter waits to receive cargoes from multiple suppliers at the berth, while the trucks wait for their turns to enter the terminal. Due to the limited space, the terminal operation becomes vulnerable to the lack of coordination of their arrivals. In this study, despite a traditional industry, we are interested in applying the emerging technologies to improve the operation efficiency. We develop a simulation-based coordination strategy to construct coordinated schedules for both the lighters and suppliers to reduce congestions in the lighterage terminal The discrete event simulation model is developed based on understanding the real-world terminal in Singapore, and the controlled arrival method, determining coordinated arrival schedules of trucks, is introduced and embedded to the simulation model. The simulation model is tuned up with a benchmark setting of 6-month historical data. To find the optimal strategy, an advanced bi-objective simulation optimization algorithm is employed. According to our findings, the proposed strategy could significantly improve the efficiency of both lighters and trucks in various indicators. At the end, a mobile application prototype is proposed to deliver the coordinated schedules to different parties, and improve the communication between parties.  相似文献   

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