绿色、和谐、以人为本的城市交通规划策略分析

本文章在借鉴、参略出发,综合阐述了土地利用考国内外先进城市交通规划理念的基础上,从绿色、和谐、以人为本的规划策交通结构一体化对城市规划的影响和意义,并从交通需求管理的角度对城市交通规划进行了全方位、深层次分析,对城市交通规划的研究和实施具有一定的借鉴和参考价值。     

Personalised feedback and eco-driving: An explorative study

Conventional road transport has negative impact on the environment. Stimulating eco-driving through feedback to the driver about his/her energy conservation performance has the potential to reduce CO₂ emissions and promote fuel cost savings. Not all drivers respond well to the same type of feedback. Research has shown that different drivers are attracted to different types of information and feedback. The goal of this paper is to explore which different driver segments with specific psychographic characteristics can be distinguished, how these characteristics can be used in the development of an ecodriving support system and whether tailoring eco-driving feedback technology to these different driver segments will lead to increased acceptance and thus effectiveness of the eco feedback technology. The driver segments are based on the value orientation theory and learning orientation theory. Different possibilities for feedback were tested in an exploratory study in a driving simulator. An explorative study was selected since the choice of the display (how and when the information is presented) may have a strong impact on the results. This makes testing of the selected driver segments very difficult. The results of the study nevertheless suggest that adapting the display to a driver segment showed an increase in acceptance in certain cases. The results showed small differences for ratings on acceptation, ease of use, favouritism and a lower general rating between matched (e.g., learning display with learning oriented drivers) and mismatched displays (e.g., learning display with performance oriented drivers). Using a display that gives historical feedback and incorporates learning elements suggested a non-verifiable increase in acceptance for learning oriented drivers. However historical feedback and learning elements may be less effective for performance oriented drivers, who may need comparative feedback and game elements to improve energy conserving driving behaviour.     

Coordinated transit signal priority supporting transit progression under Connected Vehicle Technology

In this paper, a person-delay-based optimization method is proposed for an intelligent TSP logic that enables bus/signal cooperation and coordination among consecutive signals under the Connected Vehicle environment. This TSP logic, called TSPCV-C, provides a method to secure the mobility benefit generated by the intelligent TSP logic along a corridor so that the bus delay saved at an upstream intersection is not wasted at downstream intersections. The problem is formulated as a Binary Mixed Integer Linear Program (BMILP) which is solved by standard branch-and-bound method. Minimizing per person delay has been adopted as the criterion for the model. The TSPCV-C is also designed to be conditional. That is, TSP is granted only when the bus is behind schedule and the grant of TSP causes no extra total person delay.The logic developed in this research is evaluated using both analytical and microscopic traffic simulation approaches. Both analytical tests and simulation evaluations compared four scenarios: without TSP (NTSP), conventional TSP (CTSP), TSP with Connected Vehicle (TSPCV), and Coordinated TSP with Connected Vehicle (TSPCV-C). The measures of effectiveness used include bus delay and total travel time of all travelers. The performance of TSPCV-C is compared against conventional TSP (CTSP) under four congestion levels and five intersection spacing cases. The results show that the TSPCV-C greatly reduces bus delay at signalized intersection for all congestion levels and spacing cases considered. Although the TSPCV is not as efficient as TSPCV-C, it still demonstrates sizable improvement over CTSP. An analysis on the intersection spacing cases reveals that, as long as the intersections are not too closely spaced, TSPCV can produce a delay reduction up to 59%. Nevertheless, the mechanism of TSPCV-C is recommended for intersections that are spaced less than 0.5 mile away. Simulation based evaluation results show that the TSPCV-C logic reduces the bus delay between 55% and 75% compared to the conventional TSP. The range of improvement corresponding to the four different v/c ratios tested, which are 0.5, 0.7, 0.9 and 1.0, respectively. No statistically significant negative effects are observed except when the v/c ratio equals 1.0.     

深水波频域格林函数及其高阶导数算法研究

文章研究了无限水深自由面格林函数一种新的算法,该算法将计算域重新划分为五个子区域,在每一个子区域内只涉及级数展开,没有使用插值表及数值积分,与现有格林函数算法相比,不仅给出一阶导数值,而且能高效地计算二阶导数,这在格林函数微分方程求解及高阶面元法中非常有用.数值结果表明,该方法计算速度快且一阶导数和二阶导数的计算精度达到10-9.     

Aligning the purchase of green logistics practices between shippers and logistics service providers

This paper explores shippers’ (i.e. logistics buyers) and logistics service providers’ (LSPs) perceptions of green concerns under diverse contractual settings during the key phases of the logistics purchasing process: request for proposal, negotiations, contracting and execution. Accordingly, it derives recommendations that could increase the actors’ inter- and- intra-organisational alignment on green targets throughout these phases. Empirical data are obtained from eight individual cases of three shippers and five LSPs, representing the buyer/seller roles within logistics arrangements. Contrary to previous literature holding the view that setting more green demands by shippers would guarantee green outcomes, the findings show that shippers’ green demands may hinder green logistics applications due to impediments to LSPs’ asset-sharing strategies. Also, a deadlock situation is revealed in the negotiations phase, where both actors await each other to introduce additional demands/offers—calling for further regulatory intervention to release this deadlock. Moreover, this paper shows how a mismatch of interests in contractual periods between shippers and LSPs can obstruct green investments—signalling that the green criterion is not the decisive factor in shaping shippers’ outsourcing strategies. The findings also stress a lack of follow-up efforts by shippers on green measures that were specified pre-contract, attributing this to contrasting intra-organisational objectives within shippers’ firms. This paper contributes to the green logistics purchasing literature by revealing how different contractual settings play an important role in shaping shippers’/LSPs’ perceptions of green concerns during the logistics purchasing process. Further, it is one of the first studies to provide phase-specific recommendations to increase the actors’ alignment on green targets.     

谐振面力作用下的无穷大双周期加筋板的振动响应分析

文章主要研究了流体负载下的无穷大双周期加筋薄板,在周期谐振力作用下的振动响应。假设薄板和加强筋只存在法向力的作用,通过薄板和加强筋的位移连续条件,以及格林函数及傅立叶变换公式的应用,建立了频域内双周期加筋薄板的振动位移方程。利用空间波数法,将加筋薄板的振动位移表达为波数分量的迭加形式。通过数值计算的方法对波数分量进行求解,最后通过方程的傅立叶逆变换,得到了加筋薄板的振动方程。数值计算的结果表明文中的计算方法收敛速度快。     

规则波中船舶波浪增阻理论和经验法预报分析与比较

针对规则波中迎浪下有航速集装箱船船型阻力增加预报,采用一种改进的三维移动脉动源面元法求解船舶运动,进而通过理论方法求解辐射和绕射增阻.速度势求解引入了格林函数空间线段积分和面元积分方法,辐射增阻采用三维辐射能量法计算,绕射增阻通过二阶波浪力中绕射速度势获得.通过与试验数据对比证明了该理论预报模型在精度和效率方面有明显优势.在此预报结果基础上对经验预报模型提出了改进公式,计算结果表明了改进模型对工程设计具有较好的适用性.     

半潜式钻井平台波浪散射力与运动响应分析

文章对半潜式钻井平台(Semi-Submersible)在波浪作用下的散射波浪力和运动响应进行了分析研究,研究中采用了基于波浪辐射、绕射理论的三维有限水深格林函数方法.为了保证这种大型复杂海工结构物计算结果的高精度,研究中对于边界积分方程的离散求解采用了考虑几何对称性的高阶边界元算法.通过对计算结果的比较分析,对这种型式的钻井平台的波浪力和运动响应有了一个全面的认识,对结构设计有很好的参考价值.     

系泊Spar平台波浪中耦合运动的数值模拟及模型试验

为了研究恶劣环境载荷引起海洋结构物的非线性运动响应,文章基于三维时域格林函数理论,提出了采用时域物面非线性理论方法直接模拟系泊浮体时域耦合分析所需的水动力,建立了系泊浮体波浪中时域耦合运动的数学模型.该方法充分考虑了每时每刻浮体在瞬态波面下湿表面的变化,并计及平均水线面下瞬时空间位置的改变,系统研究了系泊Spar平台波浪中的耦合运动响应及系泊线张力.最后,将数值模拟结果与模型试验结果进行了比较,计算结果令人满意.     

海底阻抗对浅海波导中椭球体的声散射研究

基于Greenberg方法推导了含有阻抗边界条件的浅水Green函数,利用边界元法研究了含阻抗的三维海洋波导与散射体相互作用的问题.分析了海底阻抗对声波与结构体相互作用时的散射特性影响,数值分析表明:含有阻抗边界条件的浅海目标的散射特性与理想海底明显不同,海底阻抗对水平断面以及垂直断面的散射场都有一定的影响,目标距离海底越近,场点散射声压受海底边界条件的影响越大;阻抗越大,散射声压越大.指向性的分布对受海底阻抗的大小比较敏感.分析浅海声散射时,海底阻抗的影响不可忽视.