基于二滩水电站550kV扩建工程GIS断路器静电场分布

二滩水电站550kv扩建工程采用的是ABB型GIS,由新东北电气（沈阳）高压开关有限公司承造.结合其1分钟工频耐压试验,文中对sf6断路器处于合闸及分闸状态灭弧室静电场进行了分析计算,并剖析了断路器在分闸过程中电场不均匀程度.     

低干舷隐身船波浪中纵向运动的模型试验及理论研究

低干舷隐身船由于采用低于舷和内倾设计,容易引起甲板上浪和非线性水动力,因而其耐波性能与传统直壁船型差别较大.文中通过模型试验和理论计算的方法,对低干舷隐身船在顶浪时规则波和不规则波中的纵向运动响应开展了研究.理论方法包括S.T.F.线性切片法和非线性时域方法,并且在时域计算中考虑了船体湿表面变化和甲板上浪对纵向运动的影响.研究表明,隐身船在波浪中的纵向运动存在明显的非线性现象,船舷内倾是导致船体纵向运动非线性的主要因素,采用非线性时域方法可以较好地预报低干舷隐身船型在波浪中的纵向运动.     

天津港GIS数据库的建设与应用

随着"数据化天津港"的发展,利用现有的GIS平台建立天津港GIS数据库已经成为高效、科学地开展天津港港务工作的重要手段.主要介绍了天津港GIS数据库的建设内容、建库流程以及关键技术等问题,阐述了GIS技术发展的前景.以及在天津港的应用情况.     

基于PMF5318T的DSP＋FPGA系统电源设计

为满足DSP＋FPGA信号处理系统设计要求,根据获得低电压的几种方法,设计一种基于PMF5318T的电源供电系统,实现了高效、稳定的电源输出。并根据电源加载的次序要求,设计成多电源顺序启动的电路。     

GIS技术在海缆路由设计中的应用

由于海底光（电）缆路由设计的复杂性、多维性和动态性以及传统平面设计方式不够形象直观的缺陷,使得应用GIS技术进行路由设计成为新的选择。文章介绍了GIS技术的发展现状、关键技术,归纳了海缆路由设计的流程、对象,重点对GIS技术在海缆路由设计中的应用进行探讨,并指出基于3D GIS技术的海缆可视化路由设计是发展趋势。     

浅谈GIS在道路管理中存在的问题

充分利用GIS对空间信息的管理能力和生动形象的图形表现形式,结合交通系统的具体特点,开发适合现代变通发展需要GIS,具有鲜明的实际意义。     

A traffic analysis zone definition: a new methodology and algorithm

This paper develops a comprehensive approach to the definition of transportation analysis zones (TAZ), and therein, presents a new methodology and algorithm for the definition of TAZ embedded in geographic information systems software, improves the base algorithm with several local algorithms, and comprehensively analyses the obtained results. The results obtained are then compared to these presently used in the transportation analysis process of the Lisbon Metropolitan Area. The proposed algorithm presents a new methodology for TAZ design based on a smoothed density surface of geocoded travel demand data. The algorithm aims to minimise the loss of information when moving from a continuous representation of the origin and destination of each trip to their discrete representations through zones, and focuses on the trade-off between the statistical precision, geographical error, and the percentage of intra-zonal trips of the resulting OD matrix. The results for the Lisbon Metropolitan Area case study suggest a significant improvement in OD matrix estimates compared to current transportation analysis practises based on administrative units.

Co-location decision tree for enhancing decision-making of pavement maintenance and rehabilitation

This paper presents a new decision tree induction method, called co-location-based decision tree (CL-DT), to enhance the decision-making of pavement maintenance and rehabilitation strategies. The proposed algorithm utilizes the co-location characteristics of spatial attribute data in the pavement database. The paper first presented the co-location mining algorithm, including spatial attribute data selection, determination of rough candidate co-locations, determination of candidate co-locations, pruning the non-prevalent co-locations, and induction of co-location rules, and then focused on the development of the co-location decision tree (CL-DT) algorithm, which includes the non-spatial attribute data selection, co-location algorithm modeling, node merging criteria, and co-location decision tree induction. A pavement database covering four counties, which are provided by North Carolina Department of Transportation (NCDOT), is used to verify the proposed method. The experimental results demonstrated that (1) the proposed CL-DT algorithm can make a better decision, and has higher accuracy than the existing decision tree methods do; (2) the training data can be fully played roles in contribution to decision tree induction and the computational time taken for the tree growing, tree drawing and rule generation is largely decreased; (3) quantity and locations of six treatment strategies proposed by the ITRC and by CL-DT is much close for each treatment strategy.     

基于GIS和BIM的航电枢纽施工动态可视化信息管理

针对在航电枢纽工程施工管理中场景可视化模拟的不足,提出航电枢纽工程信息化模型概念,并基于GIS、3 ds Max和数据库技术,建立航电枢纽工程信息化模型构建方法,实现航电枢纽全要素在全生命周期的动态可视化模拟;基于BIM 4D工程动态管理思想,提出航电枢纽施工动态可视化信息管理方法。基于依兰航电枢纽工程资料,利用GIS组件式二次开发,研发依兰航电枢纽施工动态可视化信息管理系统,验证了本文提出的施工动态可视化信息管理方法的可行性,推动水利行业现代化、信息化和规范化的进程。     

航电枢纽全视景三维模型构建方法

针对航电枢纽全视景可视化仿真,基于数字高程模型构建、参数化实体建模原理,运用GIS三维可视化技术,提出航电枢纽三维模型构建方法、数字地形系统搭建方法和多坐标系统模型耦合方法。基于ArcGIS Engine二次开发技术、空间数据库技术以及数据库连接及应用技术,完成全视景动态虚拟现实系统构建技术研究。利用本方法搭建依兰航电枢纽全视景动态虚拟现实系统,实现航电枢纽全视景动态管理,验证方法的可行性。