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排序方式: 共有434条查询结果,搜索用时 15 毫秒
1.
This paper presents the methodology and selective empirical results from a study of the demand for a high speed rail system serving the Sydney-Canberra corridor currently dominated by air travel for business trips and car travel for non-business trips. We outline the steps involved in the study from problem specification, data needs, development of base year trip tables, model specification and estimation to establish switching behaviour in the presence of a new mode and calculation of induced demand for current travellers. A stated choice heteroskedastic extreme value switching model is used to evaluate the choice of fare type for business and non-business travel given the current mode used in the corridor for each sampled traveller conventional train, charter coach, scheduled coach, plane or car. Starting with the current travel profile, patronage can be predicted under alternative fare regimes, taking into account diverted traffic, induced traffic and growth. Treating fare class as endogenous enhances the real choice context facing potential patrons.  相似文献   
2.
The article reports an experimental study of driver steering control behaviour in a lane-change manoeuvre. Eight test subjects were instrumented with electromyography to measure muscle activation and co-contraction. Each subject completed 30 lane-change manoeuvres with one vehicle on a fixed-base driving simulator. For each driver, the steering torque feedback characteristic was changed after every ten manoeuvres; the response of the vehicle to steering angle inputs was not changed. Drivers' control strategies were found to be robust to changes in steering torque feedback. Path-following errors, muscle activity and muscle co-contraction all reduce with the number of lane-changes performed by the driver, suggesting the existence of a learning process. Comparing the test subjects, there was some evidence that high levels of co-contraction were used to allow high-frequency steering inputs to be generated. The results contribute to the understanding of vehicle-driver (and more generally, human-machine) dynamic interaction.  相似文献   
3.
The dynamic parameters of a MacPherson strut suspension were estimated from the kinematic responses and measured external forces on the system. First, Lagrange equation was used to develop the equations of motion of the system, and then equations of motion were written as linear with respect to the dynamic parameters being estimated. The generalized coordinate partitioning technique was applied to create a reduced set of equations of motion of the constrained dynamic system. In this method only the measurements of positions and kinematic responses of the independent coordinates, and the external forces applied on the system are required as inputs. The rank deficient linear system was solved by QR decomposition. Good correlation was obtained between the actual parameters and the estimated parameters, by comparison between the simulated system response from the actual parameters and from the estimated parameters.  相似文献   
4.
5.
Ramp meters in the Twin Cities have been the subject of a recent test of their effectiveness, involving turning them off for eight weeks. This paper analyzes the results with and without ramp metering for several representative freeways during the afternoon peak period. Seven performance measures: mobility, equity, productivity, consumers’ surplus, accessibility, travel time variation and travel demand responses are compared. It is found that ramp meters are particularly helpful for long trips relative to short trips. Ramp metering, while generally beneficial to freeway segments, may not improve trip travel times (including ramp delays). The reduction in travel time variation comprises another benefit from ramp meters. Non-work trips and work trips respond differently to ramp meters. The results are mixed, suggesting a more refined ramp control algorithm, which explicitly considers ramp delay, is in order.  相似文献   
6.
We investigate how customers respond to an opaque airline product offered by a European carrier. In this opaque product design, customers are randomly assigned to travel to one of approximately ten destinations; however, for a fee they may exclude one or more destinations from the choice set (or a particular package design) prior to learning which destination they will travel to. We use a multidimensional binary logit model to predict the probability that one or more alternatives will be chosen by a customer. Results show that customers are more likely to pay to exclude destinations located close to the origin airport and destinations that speak the same language as the origin airport. Length of stay, cost of living at the destination, and measures of destination attractiveness are also found to be significant predictors for some package designs. Based on these findings, we offer general recommendations for how to design opaque packages for airline customers.  相似文献   
7.
Trains crashing onto heavy road vehicles stuck across rail tracks are more likely occurrences at level crossings due to ongoing increase in the registration of heavy vehicles and these long heavy vehicles getting caught in traffic after partly crossing the boom gate; these incidents lead to significant financial losses and societal costs. This paper presents an investigation of the dynamic responses of trains under frontal collision on road trucks obliquely stuck on rail tracks at level crossings. This study builds a nonlinear three-dimensional multi-body dynamic model of a passenger train colliding with an obliquely stuck road truck on a ballasted track. The model is first benchmarked against several train dynamics packages and its predictions of the dynamic response and derailment potential are shown rational. A geometry-based derailment assessment criterion is applied to evaluate the derailment behaviour of the frontal obliquely impacted trains under different conditions. Sensitivities of several key influencing parameters, such as the train impact speed, the truck mass, the friction at truck tyres, the train–truck impact angle, the contact friction at the collision zone, the wheel/rail friction and the train suspension are reported.  相似文献   
8.
This study investigates the impacts of physical environments on bicyclists’ perceptions of comfort on separated and on-street bicycle facilities. Based on a field investigation conducted in Nanjing, China, we find that physical environmental factors significantly influencing bicyclists’ perception of comfort on the two types of facility. Cyclists’ comfort is mainly influenced by the road geometry and surrounding conditions on physically separated paths while they pay attention to the effective riding space and traffic situations on on-street bicycle lanes.  相似文献   
9.
概述了欧洲几个国家列车联运网络的建设情况,指出在提高列车运行速度的同时,应提供优质的联运服务。  相似文献   
10.
We present concurrent data on ingestion, egg production and the loss of maternal biomass in pre-spring bloom female Calanus finmarchicus incubated under conditions representative of those in situ in the North Atlantic. A balanced metabolic budget was constructed and used to examine the relative importance of ingestion and biomass for fuelling egg production during the incubations. Ingested carbon was not sufficient to meet the observed demands for egg production. More than 80% of the carbon utilised by the females was instead derived from their biomass. Fatty acid analysis demonstrated that the storage reserves, 20:1 (n−9) and 22:1 (n−11), were virtually absent before experimentation began, and therefore could not have been used to supply the carbon required for egg production during the incubations. The C:N mass-specific ratio of the biomass utilised was 4.1, suggesting that the females had instead catabolised protein in order to meet their metabolic demands. These results suggest that C. finmarchicus adopts a sacrificial reproductive strategy when food availability is low.  相似文献   
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