城市交通空间的塑造与整合--评2003-2004年度中法城市交通系列研讨会

城市复杂化使得城市交通问题从一个工程问题转化成为一个系统化、复合型的社会问题。基于此,法国动态基金会和同济大学倡导并发起了基于机动性的城市交通系列研讨会。中欧专家从宏观到中观到微观,多方面、多角度地进行了交流与探讨。其中包括对区域交通规划在引导区域一体化中作用的探讨,对适应社会发展的城市交通规划理论与方法的探讨,以及对作为交通战略实现关键的交通空间设计具体方法和原则的探讨。通过这些交流活动,为我国城市交通规划与设计理论开创了崭新的视角,激发了欧洲新观点在中国的讨论和传播,也体现了一种全新的交流与合作方式。     

地铁中的移动通信终端位置管理模型

对地铁中移动通信网络移动终端的位置管理进行了研究.给出了适合于模拟移动终端在地铁中运动的移动模型,并根据该模型提出了基于线路的位置管理策略.仿真结果表明,其位置管理开销要比基于时间和基于距离两种位置管理方法的位置管理开销都小.     

离子迁移谱技术发展趋势和应用前景

离子迁移谱(IMS)最初是作为化学实验室分析技术发展起来的。近年来,这一技术日臻完善,目前已经应用在多个领域,其中包括国家军事领域的化学战剂监测,各级安全部门的爆炸物监测,海关和机场入口安检部门对毒品、麻醉剂等违禁物品的监测以及环境监测部门对有毒有害气体的监测。随着应用范围的拓宽,IMS技术引起了世界各国专家的研究兴趣,因此使得这一技术不断得到更新和发展。本文系统地介绍了IMS技术的广泛应用前景及当前的发展趋势。     

Shared versus private mobility: Modeling public interest in autonomous vehicles accounting for latent attitudes

Emerging autonomous vehicles (AVs) and shared mobility systems per se will transform urban passenger transportation. Coupled together, shared AVs (SAVs) can facilitate widespread use of shared mobility services by providing flexible public travel modes comparable to private AV. Hence, it may be conjectured that future urban mobility is likely an on-demand service and AV private ownership is unappealing. Nonetheless, it is still unclear what observable and latent factors will drive public interest in (S)AVs, the answer to which will have important implications on transportation system performance. This paper aims to jointly model public interest in private AVs and multiple SAV configurations (carsharing, ridesourcing, ridesharing, and access/egress mode) in daily and commute travels with explicit treatment of the correlations across the (S)AV types. To this end, multivariate ordered outcome models with latent variables are employed, whereby latent attitudes and preferences describing traveler safety concern about AV, green travel pattern, and mobility-on-demand savviness are accounted for using structural and measurement equations. Drawing from a stated preference survey in the State of Washington, important insights are gained into the potential user groups based on the socio-economic, built environment, and daily/commute travel behavior attributes. Key policies are also offered to promote public interest in (S)AVs by scrutinizing the marginal effects of the latent variables.     

Integrating transport and land-use planning? How steering cultures in local authorities affect implementation of integrated public transport and land-use planning

Previous research has shown integrated planning to be important for achieving aims concerning more environmentally friendly transport operations, but less good at explaining prerequisites of implementation. This paper analyses how management and working practises in local authorities, here understood as steering cultures, affect implementation of integrated land-use and public transport planning approaches. The analysis builds on case studies of planning in two Swedish municipalities. These have developed two antithetical steering cultures, namely one that can be described as deliberative and one that can be described as sectorised. The paper describes the advantages and disadvantages of these steering cultures. The findings show the deliberative model to facilitate integration through advanced mechanisms of consensus and co-ordination between policy-makers and officials. The sectorised model has no such mechanisms, but this need not result in poor prospects of integrated planning. It is important for integrated planning approaches, whatever the steering culture, to be in line with the institutionalised norms and objectives by which planning practices are governed. Integration therefore needs a normative component, so as to ensure implementation. The important normative component in this context can be construed as discourses and rationales concerning transport and the urban development of which public transport forms part.     

陕北冻土高水位流沙地段管沟开挖方法研究

高水位流沙地段的管沟开挖一直是施工过程中的难点,虽然目前可采用深井抽排降水法、密闭管抽水降水法、明渠抽排降水法、木桩固定沟壁加抽水降水法等方法,但施工工序繁琐,成本高。文中提出应用冻土原理,在一次双侧沉管的基础上,采用二次双侧开挖新方法,将地下高水位的挖沟不利条件变为有利条件,降低了土方开挖量,取消了抽排水措施,提高了施工工效,节约了施工成本。该方法在陕京三线设计1标段榆阳马家峁段AA001-AA005高水位流沙地段工程施工中取得了良好的施工工效与经济效益。     

Exploring public bicycle network structure based on complex network theory and shortest path analysis: the public bicycle system in Yixing,China

A well-functioning public bicycle system relates not only to its mode of operation, vehicle allocation, rental station layout and vehicle leasing configuration, but also the bicycle network structure and its formation. However, the latter aspects have been widely overlooked in China. Here, we help to further attract more researchers to conduct relevant studies and make suggestions for the development of public bicycle transport in many small and medium-sized cities across the world. We demonstrate how to explore the public bicycle network structure of a county-level Chinese city – Yixing – known for its clay ware and tourism. We show that complex network theory and shortest path analysis technology are useful in characterizing the public bicycle network structure, in aspects such as network topology, the spatial distribution of sub-networks and traffic flows. Finally, the paper proposes relevant urban planning strategies.     

基于模糊物元模型的战时道路通行方案优选

战时道路通行方案优选是机动工程保障方案决策的关键一环。针对战时道路通行方案包含多种技术因素和具有不确定性的特点,从道路的基本通行能力、伪装防护能力、抗打击能力、快速恢复能力4个角度出发,综合考虑影响道路通行方案的定性指标与定量指标,选取道路线型、遮蔽物、路基抗打击能力、路面的修复等15个指标,建立了战时道路通行方案的模糊物元分析模型。在分析过程中,引用层次分析法求得指标权重,用方案中各项指标的评价值及相应的模糊数构造复合模糊物元矩阵,通过计算与标准模糊物元之间的欧式贴近度来实现方案的优劣排序。以某战场环境下的道路通行方案为例证明了该方法的可行性和有效性,为战时更好的选择路线实现快速机动提供决策依据。     

设备安装对基座导纳测量的影响研究

裸基座导纳是隔振设计的重要参数.工程中常需要在设备安装状态下测量基座的导纳,这会给基座导纳测量带来误差.本文针对单个安装点的情况(低频时成立)从理论上证明了这种误差在某些条件下是可以忽略的,即设备刚性安装时基座阻抗应远大于设备机脚阻抗;弹性安装时若基座阻抗远大于隔振器阻抗,则在远大于设备安装频率的频段可忽略这种误差;若基座阻抗远大于机脚阻抗,则在设备无共振的频段亦可忽略这种误差.这些条件在工程中比较容易得到满足,因此本文结论对工程中导纳的测量具有实际指导意义.     

机械设备隔振系统的子结构建模方法研究

基于频响函数(FRF)的子结构方法是分析复杂组合结构的有效方法之一,其基本原理是使用单个非耦合的分量FRF通过阻抗或导纳方程构成总的系统响应。通过采用自由速度描述机械设备的激励特性,采用四端参数描述隔振器的阻抗特性,建立了机械设备隔振系统完整的子结构模型。经实测,获得了设备机脚的自由速度以及基座等结构的导纳矩阵,计算获得设备弹性安装后机脚和基座安装点的响应,并与测试结果进行了比较。分析表明,结果吻合较好,计算值与测试值的偏差基本在3 dB以内,能够满足工程要求。