曲轴箱漏气分析

利用你已经拥有的设备，不必借助烟度计就可以诊断出曲轴箱的漏气量以及曲轴箱强制通风（PCV）流量过低或过多这类故障。[编者按]     

Estimating commuter mode choice: A discrete choice analysis of the impact of road pricing and parking charges

Automobile use leads to external costs associated with emissions, congestion, noise and other impacts. One option for minimizing these costs is to introduce road pricing and parking charges to reduce demand for single occupant vehicle (SOV) use, while providing improvements to alternatives to encourage mode switching. However, the impact of these policies on urban mode choice is uncertain, and results reported from regions where charging has been introduced may not be transferable. In particular, revealed preference data associated with cost recovery tolls on single facilities may not provide a clear picture of driver response to tolls for demand management. To estimate commuter mode choice behaviour in response to such policies, 548 commuters from a Greater Vancouver suburb who presently drive alone to work completed an individually customized discrete choice experiment (DCE) in which they chose between driving alone, carpooling or taking a hypothetical express bus service when choices varied in terms of time and cost attributes. Attribute coefficients identified with the DCE were used in a predictive model to estimate commuter response to various policy oriented combinations of charges and incentives. Model results suggest that increases in drive alone costs will bring about greater reductions in SOV demand than increases in SOV travel time or improvements in the times and costs of alternatives beyond a base level of service. The methods described here provide an effective and efficient way for policy makers to develop an initial assessment of driver reactions to the introduction of pricing policies in their particular regions.     

Analysis of airline operating strategies under stochastic demand

Variability in the demand for air travel is studied with respect to stochastic and time varying components which affect the distribution of passengers who will want to travel on a particular day. The problem is then cast as one of optimizing the total capacity offered in a given time period using operating net revenues as the objective. The distribution of demand is assumed to be normal, and passengers lost on those days when demand is high are assumed to travel on another airline or a different mode. An airline must therefore balance the costs of increased capacity against the benefits of carrying more people. Tradeoffs are studied parametrically, with particular emphasis on the effect the variance of the distribution of demand has on different relationships. Also shown is a simple procedure for estimating actual market mean and variance given the mean and variance of the number of passengers actually flown, which has a truncated distribution.     

A warehouse location-routing problem

The interdependence between distribution center location and vehicle routing has been recognized by both academics and practitioners. However, only few attempts have been made to incorporate routing in location analysis. This paper defines the Warehouse Location-Routing Problem (WLRP) as one of simultaneously solving the DC location and vehicle routing problems. We present a mixed integer programming formulation of the WLRP. Based on this formulation, it can be seen that the WLRP is a generalization of well-known and difficult location and routing problems, such as the Location-Allocation Problem and the Multi-depot Vehicle Dispatch Problem. It is therefore a large and complex problem which cannot be solved using existing mixed-integer programming techniques. We present a heuristic solution method for the WLRP, based on decomposing the problem into three subproblems. The proposed method solves the subproblems in a sequential manner while accounting for the dependence between them. We discuss a large-scale application of the proposed method to a national distribution company at a regional level.     

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作为一种公共交通付费手段的智能卡技术的出现，对于世界各国公交产业的经营人来说不但是可行的，而且有着很好的应用背景。对于公交乘客和营运人来说，公交智能卡的优势已经带来了非常明显的方便性和好处，与传统的付费方式相比（现金支付和月票卡），使用智能卡有较快的上车时间，较低的数据调查成本，更加充分的规划利息，更有效的防止逃票和假票，以及在应用综合收费上较好的扩展能力。本文回归了世界上具有代表性的公交智能卡的应用，并阐述了今后智能卡的发展趋势，同时通过文献回顾，今后的工作将随中国公交智能卡与世界其他国家应用进行比较，以提出对中国公交智能卡发展的建议。     

能源管理与强化车体结构的结构粘合剂

结构胶粘剂是汽车制造过程中一种日趋重要的金属连接方式。文章介绍了汉高公司开发的一种汽车用结构胶粘剂的性能特点及应用工艺要求,并通过实验证明结构粘合剂对于提高车体结构性能、减轻车体质量、简化生产过程和优化生产成本来说,是一种十分有用的材料。     

A GIS-based planning approach to locating urban rail terminals

This paper develops a flexible GIS-based methodology for evaluating the potential locations of terminal park-and-ride facilities along urban rail lines. The methodology differs from political-based approaches and traditional travel demand modeling in its use of an objective measure of accessibility to gage the suitability of a site. The methodology begins by constructing an index of derived demand for rail usage based on the local demographics. Principal component analysis (PCA) is used as a means of constructing an index of derived demand consistent with other passenger surveys. Next, trade areas or commutersheds are calculated for each candidate park-and-ride location based on realistic measures of accessibility and network based drive times, taking into account competition among candidates for riders. Following the analysis, the candidate locations and their commutersheds are delineated and visualized in the GIS environment. In summary, application of this method produces a site-specific suitability index that may be used to rank and compare potential park-and-ride locations. We illustrate how our approach fits within the context of the larger-scale corridor study as a complimentary means of refining the location of urban rail stations. The analysis uses the proposed rail system for Columbus Ohio as a case study. This revised version was published online in June 2006 with corrections to the Cover Date.     

A Network Perspective on Spatially Clustered Territorial Use Rights for Fishers (TURFs) in Vietnam

Co-managed territorial use rights for fishers (TURFs) have shown promise for small-scale fisheries management. The territorial use rights help clarify access and ownership rights, while co-management arrangements create formal relationships between fishers and government. However, there is limited research into the governance processes that influence the interactions and complementarities of TURF zones that are clustered together. In a network of 16 co-managed TURFs in the Cau Hai lagoon, Vietnam, we analyzed management decentralization and the relationship between spatial and networked (social) proximity. Our findings draw attention to several broad lessons for co-managed TURFs: (1) TURFs may operate as isolated silos if co-management agreements do not address relationships among TURF leaders; (2) spatial proximity does not automatically translate to social proximity; and (3) leaders of individuals TURFs need capacity for communication and coordination with other local fisheries leaders. These findings highlight the importance of consideration to the ways that TURF design and implementation influences the relationships and collaboration between fishers, government officials, and other actors.     

The use of recovery time in timetables: rail passengers’ preferences and valuation relative to travel time and delays

Transportation - Recovery time in the rail industry is the additional time that is included in train timetables over and above the minimum journey time necessary often with the explicit aim of...     

The impacts of connected vehicle technology on network-wide traffic operation and fuel consumption under various incident scenarios

ABSTRACT

Incidents are a major source of traffic congestion and can lead to long and unpredictable delays, deteriorating traffic operations and adverse environmental impacts. The emergence of connected vehicles and communication technologies has enabled travelers to use real-time traffic information. The ability to exchange traffic information among vehicles has tremendous potential impacts on network performance especially in the case of non-recurrent congestion. To this end, this paper utilizes a microscopic simulation model of traffic in El Paso, Texas to investigate the impacts of incidents on traffic operation and fuel consumption at different market penetration rates (MPR) of connected vehicles. Several scenarios are implemented and tested to determine the impacts of incidents on network performance in an urban area. The scenarios are defined by changing the duration of incidents and the number of lanes closed. This study also shows how communication technology affects network performance in response to congestion. The results of the study demonstrate the potential effectiveness of connected vehicle technology in improving network performance. For an incident with a duration of 900?s and MPR of 80%, total fuel consumption and total travel time decreased by approximately 20%; 26% was observed in network-wide travel time and fuel consumption at 100% MPR.