排序方式: 共有96条查询结果,搜索用时 15 毫秒
81.
82.
Transportation and land-use preferences and residents’ neighborhood choices: the sufficiency of compact development in the Atlanta region 总被引:1,自引:0,他引:1
This paper analyzes the transportation and land-use preference and actual neighborhood choices of a sample of 1,455 residents
of metro Atlanta. We develop a stated-preference scale on which desires for neighborhood type are gauged, from preferences
for low-density, auto-oriented environments to desires for compact, walkable, and transit-oriented neighborhoods. This scale
is then related to desires for change in one’s own neighborhood characteristics after a hypothetical move. If all neighborhood
preferences were equally likely to be satisfied, then neighborhood preferences would not be correlated with a desire for change.
By contrast, in the current study, stronger preferences for a more walkable environment are associated with greater desire
for change in one’s neighborhood characteristics. This suggests an undersupply of compact, walkable, and transit-friendly
neighborhood types relative to current demand.
相似文献
Lawrence D. Frank (Corresponding author)Email: |
83.
Waiting time at public transport stops is perceived by passengers to be more onerous than in-vehicle time, hence it strongly influences the attractiveness and use of public transport. Transport models traditionally assume that average waiting times are half the service headway by assuming random passenger arrivals. However, research agree that two distinct passenger behaviour types exist: one group arrives randomly, whereas another group actively tries to minimise their waiting time by arriving in a timely manner at the scheduled departure time. This study proposes a general framework for estimating passenger waiting times which incorporates the arrival patterns of these two groups explicitly, namely by using a mixture distribution consisting of a uniform and a beta distribution. The framework is empirically validated using a large-scale automatic fare collection system from the Greater Copenhagen Area covering metro, suburban, and regional rail stations thereby giving a range of service headways from 2 to 60 min. It was shown that the proposed mixture distribution is superior to other distributions proposed in the literature. This can improve waiting time estimations in public transport models. The results show that even at 5-min headways 43% of passengers arrive in a timely manner to stations when timetables are available. The results bear important policy implications in terms of providing actual timetables, even at high service frequencies, in order for passengers to be able to minimise their waiting times. 相似文献
84.
Timetable design is crucial to the metro service reliability. A straightforward and commonly adopted strategy in daily operation is a peak/off-peak-based schedule. However, such a strategy may fail to meet dynamic temporal passenger demand, resulting in long passenger waiting time at platforms and over-crowding in trains. Thanks to the emergence of smart card-based automated fare collection systems, we can now better quantify spatial–temporal demand on a microscopic level. In this paper, we formulate three optimization models to design demand-sensitive timetables by demonstrating train operation using equivalent time (interval). The first model aims at making the timetable more dynamic; the second model is an extension allowing for capacity constraints. The third model aims at designing a capacitated demand-sensitive peak/off-peak timetable. We assessed the performance of these three models and conducted sensitivity analyzes on different parameters on a metro line in Singapore, finding that dynamical timetable built with capacity constraints is most advantageous. Finally, we conclude our study and discuss the implications of the three models: the capacitated model provides a timetable which shows best performance under fixed capacity constraints, while the uncapacitated model may offer optimal temporal train configuration. Although we imposed capacity constraints when designing the optimal peak/off-peak timetable, its performance is not as good as models with dynamical headways. However, it shows advantages such as being easier to operate and more understandable to the passengers. 相似文献
85.
Electric vehicles (EVs) have been regarded as effective options for solving the environmental and energy problems in the field of transportation. However, given the limited driving range and insufficient charging stations, searching and selecting charging stations is an important issue for EV drivers during trips. A smart charging service should be developed to help address the charging issue of EV drivers, and a practical algorithm for charging guidance is required to realise it. This study aims to design a geometry-based algorithm for charging guidance that can be effectively applied in the smart charging service. Geographic research findings and geometric approaches are applied to design the algorithm. The algorithm is practical because it is based on the information from drivers’ charging requests, and its total number of calculations is significantly less than that of the conventional shortest-first algorithm. The algorithm is effective because it considers the consistency of direction trend between the charging route and the destination in addition to the travel distance, which conforms to the travel demands of EV drivers. Moreover, simulation examples are presented to demonstrate the proposed algorithm. Results of the proposed algorithm are compared with those of the other two algorithms, which show that the proposed algorithm can obtain a better selection of charging stations for EV drivers from the perspective of entire travel chains and take a shorter computational time. 相似文献
86.
Development of an origin-destination demand matrix is crucial for transit planning. The development process is facilitated by automated transit smart card data, making it possible to mine boarding and alighting patterns on an individual basis. This research proposes a novel trip chaining method which uses Automatic Fare Collection (AFC) and General Transit Feed Specification (GTFS) data to infer the most likely trajectory of individual transit passengers. The method relaxes the assumptions on various parameters used in the existing trip chaining algorithms such as transfer walking distance threshold, buffer distance for selecting the boarding location, time window for selecting the vehicle trip, etc. The method also resolves issues related to errors in GPS location recorded by AFC systems or selection of incorrect sub-route from GTFS data. The proposed trip chaining method generates a set of candidate trajectories for each AFC tag to reach the next tag, calculates the probability of each trajectory, and selects the most likely trajectory to infer the boarding and alighting stops. The method is applied to transit data from the Twin Cities, MN, which has an open transit system where passengers tap smart cards only once when boarding (or when alighting on pay-exit buses). Based on the consecutive tags of the passenger, the proposed algorithm is also modified for pay-exit cases. The method is compared to previous methods developed by the researchers and shows improvement in the number of inferred cases. Finally, results are visualized to understand the route ridership and geographical pattern of trips. 相似文献
87.
控制系统和管理系统的数据共享的实现,是开发和建设企业信息管理系统中的一个关键,它的实现有利于企业管理网络的建设和提高企业的管理水平。文章论述了客户机/服务器模式下,利用开放数据库互联(ODBC)技术,实现控制系统和管理系统的数据共享的一种方法。 相似文献
88.
89.
M. Gobbi I. Haque P. Y. Papalambros G. Mastinu 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(6):437-453
This article deals with the optimal design of ground vehicles and their subsystems, with particular reference to 'active' safety and comfort. A review of state-of-the-art optimization methods for solving vehicle system design problems, including the integration of electronic controls, is given, thus further encouraging the use of such methods as standard tools for automotive engineers. Particular attention is devoted to the class of methods pertaining to complex system design optimization, as well as approaches for the optimal design of complex systems under uncertainty. Some examples of design optimizations are given in the fields of vehicle system dynamics, powertrain/internal combustion engine design, active safety and ride comfort, vehicle system design and lightweight structures, advanced automotive electronics, and smart vehicles. 相似文献
90.
一种改进的通用客户端自动升级模型及实现 总被引:4,自引:0,他引:4
在开发基于c/s结构的大型应用系统过程中,客户端的升级维护成为一个不可回避的问题.传统的手工升级方法工作量大,不可靠.分析了常用的自动升级方法,提出了一种改进的通用客户端自动升级模型.该模型的设计思想是通过服务端把新程序以二进制形式存放在多媒体数据库中,客户端探测到最新程序并自动更新.此模型已经成功应用于商业化的大型MIS系统中. 相似文献