可视化油港工艺流程管理系统的开发与实现

以某油港为模型,开发了一套可视化油港工艺流程管理系统.介绍了系统开发的背景,阐述了系统开发的方案及系统的功能,论述了系统各功能的实现,包括生成和更新二维工艺流程图功能、工艺流程和报表的自动生成功能、历史数据的查询打印和保存功能的实现.     

AASHTO 2002沥青路面永久变形叠加方法验证

沥青路面的永久变形叠加问题是永久变形研究中的难点。首先对现有的用于沥青路面中的叠加方法进行了分析,指出其不适合于永久变形叠加问题;而后对AASHTO 2002柔性路面设计指南中的永久变形叠加方法进行了简要介绍,并采用两种APA试验方法对AASHTO叠加方法进行了验证。验证结果表明,AASHTO方法并不能准确预估永久变形;应力历史对永久变形叠加结果有很大影响,而以应变硬化原理为基础的AASHTO叠加方法不能体现应力历史的影响。因此,AASHTO 2002的叠加方法还存在着一些局限,需要进行修订。     

有效预应力对PC连续刚构桥挠度的影响

以涪陵区聚云大道沙溪沟大桥工程为背景,运用有限元软件对其进行仿真模拟计算,分析了PC混凝土连续刚构桥顶板和底板的纵向预应力筋有效性的降低分别对关键截面（零号块根部截面、L／4截面、跨中截面）处挠度的影响,从而找出了一种对挠度影响最不利的纵向预应力的损失情况,即最不利组合。计算结果表明,主梁纵向预应力有效性的逐渐降低是PC混凝土连续刚构桥梁后期挠度下挠过大的主要原因之一,且当顶板纵向预应力失效50％,同时底板纵向预应力失效30％的时候,对挠度的影响最不利。文章给出了相应的控制预应力有效性降低的措施。     

Validation Metric of Degradation Model with Dynamic Performance

With more and more attention on degradation process, we need the degradation model to be accurate all over the time rather than only at some specific moments. However, the traditional validation metric only estimates difference of static features. A validation method proposed in this paper uses hypothesis testing to identify whether the distributions of experimental measurements and simulation results are consistent. Then, based on the deviation between sample means, a global validation metric which reflects the difference of degradation process between computational model and physical system all over the service time is derived from the statistics of deviation between sample means. Furthermore, curve fit method for discrete experimental measurements is introduced. The case of electro-hydraulic servo valve is studied, and the results show that the proposed validation metric is appropriate for the validation of degradation model with dynamic performance output.     

Program for catenary–pantograph analysis,PrOSA statement of methods and validation according EN 50318

DB Systemtechnik is a high-performing, customer-driven service provider that, as well as authoritatively serving the Deutsche Bahn Group by dint of its specialist knowledge is also increasingly active on the global railway market. Development and testing of pantograph models and catenary systems have been part of the company's essential activity fields from the beginning. Therefore, an efficient and high-performing simulation tool is indispensable. That is why DB Systemtechnik spent high efforts to develop the program PrOSA in cooperation with the Heinz–Nixdorf–Institut (HNI) of the university Paderborn to simulate the interaction of pantograph and catenary. This article gives an overview of the most relevant properties of PrOSA. Furthermore, it is described how the benchmark requirements were implemented and processed.     

科研设计管理信息系统数据库性能优化研究

针对708研究所自主研发的科研设计管理信息系统,应用SQL优化技术、数据查询访问优化技术和高级优化技术等方法,就单表检索及表间检索两方面展开优化研究,得到了可以适用于一般信息管理系统的指导性方法。     

基于多节点射频卡的车辆管理系统研究

射频识别技术是一种先进的自动识别技术,已经被越来越广泛地应用于交通运输和物流领域。通过以Visual Ba-sic 6.0作为开发平台,以SQL Server 2000为后台数据库,实现了INSIDE读卡设备以及DH 3000非接触式射频卡系统等在车辆管理系统中的应用,为车辆管理调度提供了理论和现实依据,从而提高了运输效率。     

浅水中低速斜航船舶水动力预报及验证与确认分析

浅水中的斜航船舶受到浅水阻塞效应和不对称流的综合影响。为预报该运动中的船舶水动力,文章采用基于定常雷诺平均纳维—斯托克斯方程的计算流体动力学方法,对浅水中做斜航运动的船舶粘性绕流场进行数值模拟。考虑低航速运动的特点,忽略航速影响下的自由面兴波,由数值计算得到水动力系数在漂角影响下的变化规律。针对计算精度问题,在数值模拟中从验证和确认角度分析和评估计算结果：通过网格收敛性分析分析数值误差与不确定度;结合试验数据考察计算模型的误差。此外,从计算区域尺度、湍流模型、边界条件、船体下沉和纵倾作用方面对模型误差的影响因素进行探讨,可为改进计算模型、提高数值模拟精度提供参考依据。     

Automatic calibration of fundamental diagram for first‐order macroscopic freeway traffic models

Despite its importance in macroscopic traffic flow modeling, comprehensive method for the calibration of fundamental diagram is very limited. Conventional empirical methods adopt a steady state analysis of the aggregate traffic data collected from measurement devices installed on a particular site without considering the traffic dynamics, which renders the simulation may not be adaptive to the variability of data. Nonetheless, determining the fundamental diagram for each detection site is often infeasible. To remedy these, this study presents an automatic calibration method to estimate the parameters of a fundamental diagram through a dynamic approach. Simulated flow from the cell transmission model is compared against the measured flow wherein an optimization merit is conducted to minimize the discrepancy between model‐generated data and real data. The empirical results prove that the proposed automatic calibration algorithm can significantly improve the accuracy of traffic state estimation by adapting to the variability of traffic data when compared with several existing methods under both recurrent and abnormal traffic conditions. Results also highlight the robustness of the proposed algorithm. The automatic calibration algorithm provides a powerful tool for model calibration when freeways are equipped with sparse detectors, new traffic surveillance systems lack of comprehensive traffic data, or the case that lots of detectors lose their effectiveness for aging systems. Furthermore, the proposed method is useful for off‐line model calibration under abnormal traffic conditions, for example, incident scenarios. Copyright © 2015 John Wiley & Sons, Ltd.     

基于GIS的公交模型数据库构建及维护

道路网络的修改直接影响公共交通线路数据的同步更新维护,大大增加了维护的工作量和复杂性。通过分析常用交通规划软件公交模型数据库的特点,研究基于动态分段技术的公交模型数据库结构。分别设计和开发了公交模型数据库的自动创建以及在不同路网间采用GIS方法进行移植的软件工具。探讨公交线路自动创建和移植的功能、算法流程、软件开发,并应用于大型工程项目。该软件工具的应用实现了公交模型数据和道路网络模型数据独立编辑,在提高工作效率的同时大大降低了维护模型和数据库的复杂性。