排序方式: 共有55条查询结果,搜索用时 171 毫秒
41.
Lawrence J. Doctors Alexander H. Day David Clelland Philip Beveridge 《Journal of Marine Science and Technology》2010,15(4):345-358
A series of carefully controlled experiments on the wave-generation characteristics of a model of a compartmented surface-effect
ship has been conducted in a towing tank. Configurations of the model included cases encompassing one subcushion and two subcushions,
as well as differing values of the pressures in the subcushions. It was shown that a reduced wave generation in the appropriate
Froude number range could be achieved in this manner. Furthermore, a previously developed theory for the wave generation of
marine vessels was verified for the model for a Froude number greater than 0.40. 相似文献
42.
Erhardt Gregory D. Mucci Richard Alexander Cooper Drew Sana Bhargava Chen Mei Castiglione Joe 《Transportation》2022,49(2):313-342
Transportation - Transportation network companies (TNCs), such as Uber and Lyft, have been hypothesized to both complement and compete with public transit. Existing research on the topic is limited... 相似文献
43.
We are living in a time of accelerating technological development, which affects us all in our professional and social lives. Using data obtained from a 2-day activity-travel-communication diary survey in the Utrecht?CAmersfoort?CHilversum region in the Netherlands, we enhance insight into the use of Information and Communication Technologies by professionals of different types. The multivariate analyses show that one quarter of the sample has traditional work arrangements with continuous work at one location and shows a relatively low use of electronic communication modes. Half the professionals are telecommuters-car commuters and have short face-to-face and email contacts or are telecommuters-public transport commuters who in contrast rely on emails and face-to-face contacts. The final quarter of the sample shows a highly fragmented temporal work pattern with intensive face-to-face and electronic contacts. 相似文献
44.
The widespread adoption of information and communication technologies (ICT) and flexible work arrangements have enabled people
to schedule their work activities in more flexible ways. New forms of working have already emerged. However, research about
flexible work schedules is still scarce. The aim of this study is to determine the factors impacting the propensity to adopt
a flexible work schedule, and establish how and to what extent the timing of work is influenced by ICTs, work, and sociodemographic
characteristics. The analysis suggests that work-related characteristics and ICT usage seem to be more important for work-schedule
flexibility than sociodemographic characteristics are. 相似文献
45.
Alexander Paz Srinivas Peeta 《Transportation Research Part C: Emerging Technologies》2009,17(6):642-661
The problem addressed here involves a controller seeking to enhance traffic network performance via real-time routing information provision to drivers while explicitly accounting for drivers’ likely reactions towards the information. A fuzzy control modeling approach is used to determine the associated behavior-consistent information-based network control strategies. Experiments are performed to compare the effectiveness of the behavior-consistent approach with traditional dynamic traffic assignment based approaches for deployment. The results show the importance of incorporating driver behavior realistically in the determination of the information strategies. Significant differences in terms of system travel time savings and compliance to the information strategies can be obtained when the behavior-consistent approach is compared to the traditional approaches. The behavior-consistent approach can provide more robust performance compared to the standard user or system optimal information strategies. Subject to a meaningful estimation of driver behavior, it can ensure system performance improvement. By contrast, approaches that do not seek to simultaneously achieve the objectives of the drivers and the controller can potentially deteriorate system performance because the controller may over-recommend or under-recommend some routes, or recommend routes that are not considered by the drivers. 相似文献
46.
Coupled renewal model of ocean viscous sublayer, thermal skin effect and interfacial gas transfer velocity 总被引:1,自引:1,他引:0
A previously developed renewal model included parameterizations for the thermal skin effect and interfacial gas transfer velocity. The more readily available cool skin data were used for an adjustment of the gas transfer parameterization. In this work, the renewal concept is extended to include the velocity difference across the viscous sublayer and to account for the stage of surface wave development. As a result, the empirical coefficients that enter the renewal model have been specified more accurately using laboratory data on the surface wind drift current. In addition, the coefficient linking the cool skin and gas transfer parameterization formulas has been determined from the probability distribution function for renewal events. A comparison of the upgraded renewal model with the thermal skin data collected during the COARE and more recent field programs and with gas transfer data collected during GasEx-01 experiment suggests that the renewal model can be a useful tool for producing a physically based parameterization for the interfacial CO2 transfer velocity. Model uncertainties associated with the effect of surface films are discussed. 相似文献
47.
This paper seeks to develop a multi-commodity network model to analyse the flow of containers within the Asia Pacific context. The model is used to evaluate the impact of container throughput in Asia's port by varying terminal handling charges and turnaround time. The three main regions analysed are north-east Asia, east Asia (Chinese port region) and south east Asia. Using the model, it could be shown that Busan port, which is an important transhipment hub in north-east Asia, could boost the container activities in the north-eastern part of China by improving its service quality. It is also found that the efficiency of the land link between Hong Kong and mainland China plays a crucial role for the future of Hong Kong port. While Singapore port maintains its position as a transhipment hub in south-east Asia, there would be expected competition from neighbouring low costs ports. 相似文献
48.
Gaspar L. Gil Gómez Alexander Lönnergård Mohit H. Asher Mikael Nybacka Egbert Bakker Lars Drugge 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(7):945-969
Objective testing of vehicle handling in winter conditions has not been implemented yet because of its low repeatability and its low signal-to-noise ratio. Enabling this testing, by identifying robust manoeuvres and metrics, was the aim of this study. This has been achieved by using both experimental data, gathered with steering-robot tests on ice, and simulation models of different complexities. Simple bicycle models with brush and MF-tyre models were built, both optimally parameterised against the experimental data. The brush model presented a better balance in complexity performance. This model was also implemented in a Kalman filter to reduce measurement noise; however, a simpler low-pass filter showed almost similar results at lower cost. A more advanced full vehicle model was built in VI-CarRealTime, based on kinematics and compliance data, damper measurements, and real tyre measurements in winter conditions. This model offered better results and was therefore chosen to optimise the initial manoeuvres through test design and simulations. A sensitivity analysis (ANOVA) of the experimental data allowed one to classify the robustness of the metrics. Finally, to validate the results, the proposed and the initial manoeuvres were tested back to back in a new winter campaign. 相似文献
49.
The surge of road pricing projects in the U.S. and around the globe over the past 15 years has been enabled by a variety of new communication and transportation technologies. While all of these technologies increase the efficiency of roadway tolling vis-à-vis manual collection, no “best” configuration has emerged. Rather, optimal configurations depend on the objectives of the tolling effort, such as facility type, geographic scope, desire to price externalities, integration with other operations, and so on. While such policy objectives for road pricing have been examined extensively, little has been written on the explicit links between tolling technology configurations and policy objectives. This paper addresses this gap in the literature through an examination of eight road pricing programs. For each program we evaluate the conduct of the three technical tasks via the nine technology sets in light of six principal policy objectives of road pricing. 相似文献
50.
打开任何一份报纸的经济版你会发现越来越多有关汽车行业现状的坏消息。就在笔者撰写此文之时.我们刚看到Dana档案的第11章.捷豹放弃了统一平台的计划.同时大众的CEO Bemd Pischetsrieder正忙于应对工会扬言要罢工的状况。 相似文献