志愿者地理信息研究与应用初探

随着计算机技术与互联网技术、卫星定位技术、移动终端技术的发展,地理信息服务的模式正在发生改变,志愿者地理信息时代悄然而来。文章以志愿者地理信息的产生为索引,从数据的采集、处理、管理和质量控制等方面就国内外志愿者地理信息的研究与应用情况进行了回顾,讨论了目前志愿者地理信息存在的问题与发展趋势。     

基于ArcGIS Server的地震应急数据与服务共享研究

ArcGIS Server是基于Web Service用来发布企业级GIS应用程序的综合平台。 本文以地震应急数据与服务共享为研究目标, 分析了ArcGIS Server的体系架构和几种常用共享模式的特点, 提出了基于Web Service和ArcGIS Server的共享模式, 详细阐述了地震应急数据与服务共享的理论方法和系统架构, 实现了基于ArcGIS Server开发地震应急信息共享的原型系统。     

基于Django框架的两种Web地震目录分页方法

在搭建基于Django框架的地震目录服务系统过程中,为实现地震目录的快速展示,介绍了在Web服务层和数据库服务层进行数据分页的方法,并实测了两者的Web响应速度。结果表明:当数据量较大时,在数据库服务层实现分页的效率更高。     

基于SOA的GIS应用设计与实现

随着网络技术的快速发展,SOA作为构建企业级分布式软件系统的思想和方法学,已经得到了越来越广泛的应用.本文主要探讨了如何基于SOA技术实现传统的GIS应用系统.首先,我们介绍了SOA解决的GIS系统中模块复用的两大问题:封装和组合,以及现阶段还存在的问题,如海量数据和QoS等,接着简单介绍了当前SOA在GIS中的应用情景.最后,我们通过一个小型校园GIS服务应用实例PKUMAP,详细阐述了如何利用SOA的核心技术,如SCA,BPEL来构建GIS应用系统.     

基于Web的流动地震监测数据库查询系统的设计与实现

介绍了基于Web的流动地震监测数据库查询系统的开发背景和目的,描述了数据库查询系统的设计和实现过程。该系统借助Internet/Intranet网络,以B/S(浏览器/服务器)体系结构作为基础架构,采用WAMP集成化软件开发,具有系统加密、数据查询、数据维护、数据导出和资料下载等功能。     

XML在统计地理信息Wed发布中的应用

结合统计地理信息Web发布系统的开发与实践,介绍了系统的总体结构以及系统建设与维护的XML策略,并分别对服务器端、服务器端与客户端的请求与应答、客户端的XML语义进行了详细描述,说明了全面采取XML策略的意义。     

A modified binary space partitioning tree for geographic information systems

We present a reactive data structure, that is, a spatial data structure with detail levels. The two properties, spatial organization and detail levels, are the basis for a geographic information system (GIS) with a multi-scale database. A reactive data structure is a novel type of data structure catering to multiple detail levels with rapid responses to spatial queries. It is presented here as a modification of the binary space partitioning tree that includes the levels of detail. This tree is one of the few spatial data structures that does not organize space in a rectangular manner. A prototype system has been implemented. An important result of this implementation is that it shows that binary space partitioning trees of real maps have O(n) storage space complexity in contrast to the theoretical worst case O(n² ), with n the number of line segments in the map.     

Integrating GIS and data warehousing in a Web environment: A case study of the US 1880 Census

While the business intelligence sector, involving data warehouses and online analytical processing (OLAP) technologies, is experiencing strong growth in the IT marketplace, relatively little attention has been devoted to the problem of utilizing such tools in conjunction with GIS. This study contributes to the development of this research area by examining the issues involved in the design and implementation of an integrated data warehouse and GIS system that delivers analytical OLAP and mapping results in real‐time across the Web. The case study chosen utilizes individual records from the US 1880 population census, which have recently been made available by the North Atlantic Population Project. Although historical datasets of this kind present a number of challenges for data warehousing, the results indicate that the integrated approach adopted offers a much more flexible and powerful analytical methodology for this kind of large social science dataset than has hitherto been available.     

Community-based production of geographic information using open source software and Web 2.0

This article presents an innovative approach to citizen-led production of Web-based geographic information where new and/or existing digital map features are linked to annotations or commentary and citizens engage in synchronous and/or asynchronous discussion. The article discusses the relationship of the approach to public participation geographic information systems (PPGISs) and the emerging challenges associated with volunteered geographic information. A custom-developed, open source software tool named MapChat is used to facilitate the citizen inputs and discussions. The information generated from applying the approach through a series of community workshops is presented and discussed in light of current issues in PPGIS and volunteered geographic information research.     

Trust in Web GIS: the role of the trustee attributes in the design of trustworthy Web GIS applications

Since the introduction of Xerox PARC Map Viewer, there is a high growth in the number of Web GIS (Geographical Information System) applications for public use in different contexts. These applications instruct, advise and provide the tools for spatial analysis to their users, and the people who use them depend or rely on these systems. Many of these users are non-experts who have no GIS expertise and a limited understanding of spatial data handling. These inherent characteristics of non-expert interaction establish risk and uncertainty, which are further increased due to the complexity of Web GIS interfaces. These issues of uncertainty, risk perception and dependence are all trust-related aspects. Online trust has been repeatedly identified as a major concept for online information systems and its value recognised as it influences the intentions to use and the acceptance of online systems and the overall user experience. However, there is a very limited understanding as to exactly how trust is constructed when people, especially non-experts, interact with Web GIS. To improve knowledge in this domain, this article explores the theoretical foundations on how trust can be investigated in this context. Trust studies (mainly from the e-commerce domain) suggest that a trust-oriented interface design may improve the trustworthiness of online systems, and such attention can be given to Web GIS interfaces. Such studies are reviewed and their applicability is considered in the Web GIS context, taking into consideration their special characteristics. A case study is used to discuss how some features may potentially influence the trustworthiness of Web GIS applications. This article concludes by suggesting future research directions for the implementation of a holistic approach, which is necessary to investigate trust in this context.