Commuting and wellbeing: a critical overview of the literature with implications for policy and future research

ABSTRACT

This review provides a critical overview of what has been learnt about commuting’s impact on subjective wellbeing (SWB). It is structured around a conceptual model which assumes commuting can affect SWB over three time horizons: (i) during the journey; (ii) immediately after the journey; and (iii) over the longer term. Our assessment of the evidence shows that mood is lower during the commute than other daily activities and stress can be induced by congestion, crowding and unpredictability. People who walk or cycle to work are generally more satisfied with their commute than those who travel by car and especially those who use public transport. Satisfaction decreases with duration of commute, regardless of mode used, and increases when travelling with company. After the journey, evidence shows that the commute experience “spills over” into how people feel and perform at work and home. However, a consistent link between commuting and life satisfaction overall has not been established. The evidence suggests that commuters are generally successful in trading off the drawbacks of longer and more arduous commute journeys against the benefits they bring in relation to overall life satisfaction, but further research is required to understand the decision making involved. The evidence review points to six areas that warrant policy action and research: (i) enhancing the commute experience; (ii) increasing commute satisfaction; (iii) reducing the impacts of long duration commutes; (iv) meeting commuter preferences; (v) recognising flexibility and constraints in commuting routines and (vi) accounting for SWB impacts of commuting in policy making and appraisal.     

高速路网不停车收费车道优化布设方法

合理设置高速公路收费站ETC (Electronic Toll Collection)车道数量，对高速公路通行效率至关重要。针对目前路网中ETC与MTC (Manual Toll Collection)车辆混行的情况，考虑ETC的普及率，结合多用户路网均衡模型和排队论方法，建立基于双层规划模型的高速路网ETC车道优化布设方法。上层模型以车辆总通行时间最小为目标，优化设置进出收费站的ETC车道数量；下层模型为多用户路网均衡模型，反映ETC和MTC车辆的路径和收费车道选择行为。下层模型通过设计收费站的等价拓扑结构，表征收费站的车道使用规则及车辆的收费车道选择行为，并采用排队论方法估计ETC和MTC车道的收费排队时间。根据模型的特点设计了基于主动集的启发式算法，利用参数二进制与拉格朗日函数法确定迭代下降方向，解决了下降方向与步长难以计算的问题；通过内嵌优化函数的方式，保证在主动集转化过程中上层约束均不会失效，且避免了迭代过程中的模型解退化问题。基于上海市绕城高速进行实证分析，结果表明：随着ETC普及率的提升，收费排队时长按照负指数趋势下降；与按比例布设ETC车道的方法相比，所提方法最高可降低57.4%的收费排队时间，且该方法可以避免ETC车道布设过多对于MTC车道通行能力挤压造成的负面效果。研究成果可以有效指导高速路网ETC车道的布设，提高路网通行效率。     

基于物元分析法的公路桥梁损伤等级评定研究

在构建桥梁损伤等级评定指标体系的基础上，采用 AHP确定了各指标的权重，运用物元分析的方法建立了桥梁损伤等级评定的数学模型，并利用模型评定结果，得到了某桥梁的损伤等级。     

Cost scaling based successive approximation algorithm for the traffic assignment problem

This paper presents a cost scaling based successive approximation algorithm, called ε-BA (ε-optimal bush algorithm), to solve the user equilibrium traffic assignment problem by successively refining ε-optimal flows. As ε reduces to zero, the user equilibrium solution is reached. The proposed method is a variant of bush-based algorithms, and also a variant of the min-mean cycle algorithm to solve the min-cost flow by successive approximation. In ε-BA, the restricted master problem, implying traffic equilibration restricted on a bush, is solved to ε-optimality by cost scaling before bush reconstruction. We show that ε-BA can reduce the number of flow operations substantially in contrast to Dial’s Algorithm B, as the former operates flows on a set of deliberately selected cycles whose mean values are sufficiently small. Further, the bushes can be constructed effectively even if the restricted master problem is not solved to a high level of convergence, by leveraging the ε-optimality condition. As a result, the algorithm can solve a highly precise solution with faster convergence on large-scale networks compared to our implementation of Dial’s Algorithm B.     

关于构建海上医疗救助制度的探讨

文中通过分析海上医疗救助与海上人命救助的区别,指出建立海上医疗救助制度的意义,并对建立此制度的途径进行了有益的探讨。     

基于灰色理论的雪山梁隧道施工过程渗漏水水源识别研究

为了解决黄龙景区雪山梁隧道开挖过程中的涌水水源识别问题,结合黄龙景区雪山梁隧道的相关施工资料,依据已有的地质资料和涌突水预测,通过水分析化学实验,采用灰色理论计算方法研究不同水系之间的关联度;而后针对单一水源和混合水源分别进行试验和分析,得出雪山梁隧道出口段内渗漏水来源最可能为大气降水,关联度较高的还有淘金沟上游水系和隧道出口处水系;最后进行比对,得出隧道渗漏水主要来源是大气降水和淘金沟上游水体的结论,并依据现场资料及实地踏勘,验证了灰色理论分析结果的可靠性。     

基于发动机台架考核方法的气缸盖高周疲劳特性研究

依据发动机台架考核规范,运用疲劳强度理论,对某铸铁气缸盖进行高周疲劳强度评估。明确温度和应力随考核工况改变的变化行为,研究气缸盖各区域受工作载荷的影响状况,为缸盖寿命评估模型提供载荷边界。结合疲劳理论,在考虑材料修正的基础上进行了疲劳特性分析和损伤状况分析。分析表明,气缸盖各区域的疲劳安全系数均大于1,视为安全,但冷却钻孔区域的安全裕度较小。     

笑在唇边苦涩生——王蒙小说的幽默文体特色浅析

幽默作为文体形式是王蒙的创造,他灵活地运用这一具体而独特的形式表现灵魂生活,解释和反映现实世界。把众多我们习以为常的不合理的现象重新审视,以幽默的文体形式进行批驳揭露。王蒙的幽默文体给人的不是开怀大笑,而是会心的笑,苦涩的笑,由此引发读者的共鸣。作者强烈的爱国心、使命感使他的感情十分投入,叙述无遮拦、不隐蔽的表达,无限缩小了他与作者和读者之间的距离,实现了作家与读者之间穿越时空的心灵交流。     

机动车交通流比功率与能耗模型研究

为研究机动车交通流能耗,将机动车交通流比功率(VSP)作为研究对象.从最常见的单车比功率研究出发,使用气体动力学交通流模型联系单车比功率与交通流整体比功率,以此建立交通流比功率模型.为使此模型具备更显著的物理意义,将交通流比功率分为两部分,一部分为平衡交通流状态下的比功率,另一部分为偏离平衡交通流状态导致的比功率变化量,模型中的交通流参数与变量能够通过现有的交通流探测设备获取.将比功率理论模型从单车扩展到了交通流,用数学公式反应了交通流状态与比功率的关系,并且证明了交通流比功率能够通过交通流参数进行估计.并由交通流比功率出发,推导出交通流比功公式.此外研究了平衡态交通流比功率及比功与密度的关系.为研究机动车交通流能耗探索了新的思路.     

西非海域FPSO多点系泊系统的疲劳寿命分析

文章首先采用三维频域理论分析西非海域FPSO的水动力性能,得到船体各自由度的运动响应,慢漂载荷,附加质量和势流阻尼等;随后,利用分块法将波浪散点图离散为若干个海况,基于准动态方法对多点系泊系统进行分析,得到各海况下船体的漂移和各系泊缆的张力;最后,结合前两步的计算结果,采用T-N曲线,雨流计数和Miner线性累计损伤理论对系泊缆的疲劳寿命进行预报。研究结果表明,各系泊缆的疲劳寿命沿长度方向的分布趋势基本一致,锚链顶端和触底部分的疲劳寿命较短。此外,西非海域的涌浪对系泊缆的疲劳损伤较大,系泊设计时应予以重点关注。