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991.
In this paper we review freight forecasting models and current advances and needs with respect to data and model development.
We then present a case study to suggest which models should be developed for the State of California in the US. We suggest
several alternatives including an aggregate commodity flow model, a disaggregate regional logistics model and a hybrid regional
logistics model with a truck touring model. We point out however, that the data requirements for the latter model would be
extensive. In addition, the development of hybrid models, for example progress in the integration of regional logistics models
with urban truck touring models, will introduce new problems such as reconciling the outputs of multiple models for consistency. 相似文献
992.
A tool for measuring the “completeness” of a complete street has applications in developing policy, prioritising areas for infrastructure investment for a network, and solving the right-of-way allocation problem for individual streets. A literature review was conducted on the state-of-art in the assessment complete street designs. Complete streets assessment requires a context-sensitive approach, thus context-sensitive standards of “completeness” must first be established by combining a street classification system with sets of priorities and target performance levels for the different types of streets. Performance standards should address a street’s fulfilment of the movement, environmental, and place functions, and be flexible enough to account for the many ways that these functions of a street can be fulfilled. Most frameworks reviewed are unsuitable for evaluating complete streets because, with few exceptions, they guide street design by specifying the design elements for inclusion on the street. Secondly, the performance of a street can be assessed according to transportation, environmental, and place criteria, and compared to the target performance levels specified by the street’s classification. As there are many different impacts to consider on a street, additional work is required to define the priorities and performance objectives for different types of streets. 相似文献
993.
Mustapha Harb Yu Xiao Giovanni Circella Patricia L. Mokhtarian Joan L. Walker 《Transportation》2018,45(6):1671-1685
Automated driving technologies are currently penetrating the market, and the coming fully autonomous cars will have far-reaching, yet largely unknown, implications. A critical unknown is the impact on traveler behavior, which in turn impacts sustainability, the economy, and wellbeing. Most behavioral studies, to date, either focus on safety and human factors (driving simulators; test beds), assume travel behavior implications (microsimulators; network analysis), or ask about hypothetical scenarios that are unfamiliar to the subjects (stated preference studies). Here we present a different approach, which is to use a naturalistic experiment to project people into a world of self-driving cars. We mimic potential life with a privately-owned self-driving vehicle by providing 60 h of free chauffeur service for each participating household for use within a 7-day period. We seek to understand the changes in travel behavior as the subjects adjust their travel and activities during the chauffeur week when, as in a self-driving vehicle, they are explicitly relieved of the driving task. In this first pilot application, our sample consisted of 13 subjects from the San Francisco Bay area, drawn from three cohorts: millennials, families, and retirees. We tracked each subject’s travel for 3 weeks (the chauffeur week, 1 week before and 1 week after) and conducted surveys and interviews. During the chauffeur week, we observed sizable increases in vehicle-miles traveled and number of trips, with a more pronounced increase in trips made in the evening and for longer distances and a substantial proportion of “zero-occupancy” vehicle-miles traveled. 相似文献
994.
Demand for commercial air travel has been increasing over the years and recent forecasts indicate similar future trends. New aircraft with enhanced design features are being built and entering the airline service globally. These enhancements aim to ensure continued safety, efficiency, performance and prolonged life serviceability. However, these new enhancements often neglect the impact of the changing anthropometric characteristics of the passenger. Past studies have identified increasing trends in the average weight, height and other anthropometrical and biometrical measures of people at a global scale. However, many are limited to only exploring the ramifications primarily from the perspective of passenger experience. This paper highlights the importance of considering passengers’ anthropometric characteristics from a holistic perspective and identifies gaps for future research. 相似文献
995.
Segmental linings in shield tunnelling are composed of segments and joints. Mechanical behaviors of the joints govern overall behaviors of tunnel linings. Two new types of joints are adopted in Shanghai Metro Line 18, including the fast-insertion joints for adjacent rings, and the fast-slide joints for adjacent segments. In order to explore the overall behavior of segmental linings with these new types of joints, the full-scale tests are carried out for new lining structure with aligned and staggered longitudinal joints. The mechanical behaviors of the tunnel linings under different loading conditions are obtained. Furthermore, the calculation models of the tunnel linings are discussed, and regarding the modified routine method, the structural design parameters under different loading conditions are calculated, which provides a reference for the design and the comparison of the assembly method of the tunnel linings with new types of joints. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
996.
Wu Y.Zuo Q.Yan T. 《现代隧道技术》2018,(3):61-68
For water-rich slate, surrounding rock argillization and softening is a serious problem. At present the uni-axial saturated compressive strength of rock is used as one of the indexes for classification of water-rich slate sur-rounding rock. Since Banxi Group slate has special geological characteristics, the above mentioned grading index is not completely suitable for its surrounding rock classification due to limitations. For this reason, using the Youfang-ping tunnel at the Changsha to Kunming Section of the Shanghai to Kunming high-speed railway in China as an ex-ample, a softening coefficient is introduced, and the underground water, rock mass integrity coefficient and angle of the main structural surface and tunnel axis are regarded as the main controlling factors. A system of surrounding rock classification for tunnels in water-rich slate is established. Based on the theory of fuzzy mathematics, the member-ship function of each index is structured and the weight of each index is calculated by AHP, and the grade of the sur-rounding rock is determined according to the maximum membership degree principle. The results show that the fuzzy information of surrounding rock classification is processed effectively and the classification of surrounding rock is achieved by qualitative analysis to quantitative evaluation by using fuzzy theory. The surrounding rock classification determined by introducing the softening coefficient on the basis of fuzzy theory is close to that determined in practical application, indicating that the practicability of this classification of tunnel surrounding rock in water-rich slate is high. This classification system therefore is a reference for the design and construction of tunnels in water-rich slate. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
997.
The new Badaling tunnel is the longest tunnel on the under-construction Beijing-Zhangjiakou highspeedrailway, with the Badaling Great Wall station to be built in the tunnel. This station, which is under the Badaling Great Wall historic site, is the world’s largest underground high-speed railway station with the most complicated structure and the largest overburden and excavation area. It is therefore a representative project for China’s highspeed railway development strategy, supporting infrastructure facilities for the Beijing Horticultural Expo 2019 and the 2022 Winter Olympics in Beijing, and it is important that it be of high quality and completed safely. In the de-sign and construction of the station, the glyphs of the Chinese characters of "中",”国”,”人”and”品”are used, re-spectively, along the station route, in the rescue and evacuation mode, auxiliary adit and partial excavation, which is a way to successfully integrate the art of Chinese characters into tunnel engineering. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
998.
Feng Q.Cao J. 《现代隧道技术》2018,(3):193-199
For the bed rock of the foundation pit of the Bandar Malaysia North Station (BMNS) in Kuala Lumpur,the karst, fissure and cave are very developed, and curtain grouting, spud grouting and compaction grouting were conducted to achieve waterproofing and reinforcement. A Lugeon test and pumping test were carried out to test the grouting performance. The results show that the waterproofing effect of the Bandar Malaysia North Station (BMNS) is significant, meeting the basic requirements for waterproofing. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
999.
Deng T.Jin Y.Wu P.Wei W.Cao Y. 《现代隧道技术》2018,(3):69-75
A systematic analysis and discussion of the causes of house cracking are conducted by testing the blast vibration velocity of typical neighboring houses, analyzing the types of house cracking, monitoring the characteris-tics of house cracks and calculating the temperature stress at the roof and wall based on an assessment of highway tunnel blasting vibrations leading to cracking of neighboring houses. The results show that the main cause of house cracking adjacent to the tunnel is temperature stress, not blasting vibration. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
1000.
This study evaluated the potential impact of global fish trade on local food prices by analyzing a 16-year locally collected time series of disaggregated coral reef fish products and prices that differed in their market chain linkages—ranging from local to international markets. We were primarily interested in evaluating how local and global markets interacted with the local prices of beef, fish, and maize. There was no cointegration between the prices of exported octopus and that of maize and beef over this study period. Further, the three types of fish and associated markets responded in different ways to various price changes. For internationally traded octopus, we found a positive association between price and catch rates but no evidence that the global trade in octopus markets created local inflation, particularly the prices of the fish eaten by the poor. In general, there was no evidence for price transmission from export to nonexport fish products even though fishers appeared to focus on octopus when prices were high. Consequently, fishers' behaviors and trade policies that promote adjusting fishing effort to internationally traded fish did not appear to promote poverty or food insecurity in this fishery. 相似文献