柱洞法在北京地铁车站工程施工中的应用

以北京地铁15号线学院路站为研究背景,通过查阅资料、咨询专家并进行数值模拟等手段,确立了对导洞内土体进行深孔劈裂注浆措施,加固土体并形成隔水层,取代了传统的地面降水,节约了场地,消除了因降水造成地层水土流失而引起周边建(构)筑物的不均匀沉降,也避免了城市地下水资源浪费。将原来柱洞法的6导洞改为8导洞,钻孔灌注桩改为人工挖孔桩,并对车站结构施工工序进行了优化。工程实践表明,修改后的施工方案缩短了工期,提高了施工效率,效益较好。     

大连新建地铁对公交出行选择的影响

为了分析城市新建地铁项目对居民公共交通出行的影响,改善公交服务水平,提高公共交 通的分担率,针对大连市新建地铁线路展开研究。以大连市地铁1 号线沿线站点作为研究区域, 采用SP （Stated Preference） 调查方法,收集了300 名地铁沿线居民对常规公交以及新建地铁两种 出行方式的选择数据。通过建立二项Logit 模型,分析出行成本、换乘时间等选择方案特性变 量,出行特性变量以及出行者特性变量对于居民出行方式选择行为的影响,并计算弹性值及模型 精度。结果表明,通过调整出行成本及换乘时间可有效提高地铁分担率。由此提出相关政策建 议：对于出行成本,可从出行者年龄及出行次数两方面制定不同的优惠政策;对于换乘时间,可 从提高可达性、完善购票系统以及调整发班频率三方面进行改善。     

非完美信息下京津冀区域物流设施选址研究

针对大规模物流设施选址问题,本文构建了非完美信息下设施可靠性选址的连续逼近模型.该模型不仅考虑了设施存在损坏的可能性,而且考虑了由于信息缺失顾客无法获得设施状态且存在返回出发地的行为.由于该模型的结果无法直接确定设施选址点,因此采用Disk算法对该模型的结果进行离散化,获得物流设施选址方案.以京津冀区域物流设施选址为例,验证了该模型有效性并对设施布局特性进行了分析.最后,通过灵敏度分析探讨了不同参数对京津冀区域物流设施选址的影响.     

自升式钻井平台方案评价指标体系及评价方法研究(英文)

本文对白升式钻井平台的方案评价指标体系和评价方法进行了研究,提出了一套适用于自升式钻井平台的方案评价指标体系,并采用改进的灰关联分析法进行平台方案的优选,初步分析和计算实例表明,该评价指标体系和评价方法是适用和可靠的.通过对联分析方法进行改进,建立了适用于自升式钻井平台方案选优的灰关联多目标综合评价模型,该模型在灰关联分析的基础上引进层次分析法计算各指标的权重值,既在一定程度上考虑了设计方案各指标间的关联性,反应了事物的客观本质,又能体现船东的主观偏好和设计者的设计需要.同时该方案评价指标体系和评价方法具有拓展性,可应用于其它类型的移动式平台,作为方案选择时的参考依据.     

iFIX中如何通过GES OPC Server与GE PLC通讯

介绍了OPC应用的工业控制领域。OPC采用客户机/服务器体系结构,是目前工业控制中广泛采用的一项技术。OPC接口凭借其开放性、可靠性,已经成为一种国际标准。各个自动化厂商的产品可以通过OPC接口实现无缝连接。本文主要阐述iFIX组态软件的OPC连接功能,具体介绍了iFix作为OPC客户端,如何通过GES OPC Server读取GE PLC符号变量,并给出具体实施方案。     

Numerical simulations of fatigue crack initiation and propagation based on re-tensile plastic zone generating load criterion for in-plane gusset welded joints

Many accidents are caused by fatigue in welded built-up steel structures, and so it is important to estimate the fatigue lives of such structures quantitatively for safety reasons. By assuming that fatigue cracks cannot grow without an accumulation of alternating tensile/compressional plastic strain, one of the authors identified an improved effective stress intensity factor range ΔK _RPG based on the re-tensile plastic zone generating (RPG) load, which represents the driving force for fatigue cracks, and suggested that ΔK _RPG should be used as the parameter to describe fatigue crack growth behavior. The “FLARP” numerical simulation code in which ΔK _RPG is implemented as the fatigue crack growth parameter, was developed in order to predict fatigue crack initiation and propagation behavior. In this paper, it is demonstrated that FLARP gives accurate estimates for fatigue life by comparing the estimated fatigue crack growth curves and S–N curves with the experimental results for in-plane gusset welded joints, which are used in many welded steel structures. Moreover, the effect of induced bending moment due to the linear misalignment in the out of plane direction on the fatigue strength of in-plane gusset welded joints is investigated through numerical simulations.     

采用B／S模式来实现C／S模式下物资管理系统的优化

本文通过对C／S和B／S模式物资管理系统在使用中优缺点的分析,提出了采用以C／S模式为主,B／S模式为辅的混合模式对当前单一的C／S模式物资管理系统进行改造的设想。在这种混合模式下,物资管理部门内部采用C／S模式,便于实现复杂的管理功能及可靠的安全机制：对于非物资管理部门的用户,采用B／S模式,便于统一管理与维护。最后,本文还对系统改造的开发环境和技术做了探讨。     

液化石油气(LPG)汽车的优点及存在的问题

液化石油气（英文缩写为LPG）做为一种新型的能源,可以有效地治理汽车尾气污染．改善大气环境。本文阐述了LPG汽车的优点及工作中存在的若干问题,并提出解决办法。     

应用框架的设计及安全管理构件的实现

框架实现了代码重用、设计重用、以及分析重用,从而大幅度降低了开发的成本,提高了生产效率和产品质量。因此,对框架的研究和实践越来越引起学术界和产业界的高度重视。本文通过对某电网调度系统的深入调研,利用领域工程知识,设计了一个基于J2EE平台的综合应用框架,并实现了部分功能。     

Efficient missing data imputing for traffic flow by considering temporal and spatial dependence

The missing data problem remains as a difficulty in a diverse variety of transportation applications, e.g. traffic flow prediction and traffic pattern recognition. To solve this problem, numerous algorithms had been proposed in the last decade to impute the missed data. However, few existing studies had fully used the traffic flow information of neighboring detecting points to improve imputing performance. In this paper, probabilistic principle component analysis (PPCA) based imputing method, which had been proven to be one of the most effective imputing methods without using temporal or spatial dependence, is extended to utilize the information of multiple points. We systematically examine the potential benefits of multi-point data fusion and study the possible influence of measurement time lags. Tests indicate that the hidden temporal–spatial dependence is nonlinear and could be better retrieved by kernel probabilistic principle component analysis (KPPCA) based method rather than PPCA method. Comparison proves that imputing errors can be notably reduced, if temporal–spatial dependence has been appropriately considered.