Integrating GI with non-GI services—showcasing interoperability in a heterogeneous service-oriented architecture

The concept of a service-oriented architecture provides a technical foundation for delivering, using, and integrating software. It can serve as an approach to integrate GIS with other, non-GIS applications. This paper presents and discusses a service-oriented architecture that embraces a GIS and an enterprise resource planning system. The two information systems make mutually required functionalities available as services. This defines the showcase for making GI and non-GI services syntactically and semantically interoperable. The services-based integration leverages open-standard interfacing and, thus, removes syntactic heterogeneity. The integration is discussed in terms of an emergency management scenario. This scenario also helps to outline challenging semantic interoperability issues. When services provided by GIS and non-GIS applications interact, the problem arises how their different conceptualizations should be mapped. This paper analyzes essential ontological distinctions for mapping conceptual schemes in GI locator services and non-GI services. It proposes a hybrid decentralized approach of concept mapping, based on a common top-level ontology.     

The LEMO annotation framework: weaving multimedia annotations with the web

Cultural institutions and museums have realized that annotations contribute valuable metadata for search and retrieval, which in turn can increase the visibility of the digital items they expose via their digital library systems. By exploiting annotations created by others, visitors can discover content they would not have found otherwise, which implies that annotations must be accessible and processable for humans and machines. Currently, however, there exists no widely adopted annotation standard that goes beyond specific media types. Most institutions build their own in-house annotation solution and employ proprietary annotation models, which are not interoperable with those of other systems. As a result, annotation data are usually stored in closed data silos and visible and processable only within the scope of a certain annotation system. As the main contribution of this paper, we present the LEMO Annotation Framework. It (1) provides a uniform annotation model for multimedia contents and various types of annotations, (2) can address fragments of various content-types in a uniform, interoperable manner and (3) pulls annotations out of closed data silos and makes them available as interoperable, dereferencable Web resources. With the LEMO Annotation Framework annotations become part of the Web and can be processed, linked, and referenced by other services. This in turn leads to even higher visibility and increases the potential value of annotations.     

基于.Net平台的地理信息Web服务研究与应用

未来是网络为中心的世界,发布于2000年秋天的.NET计划是微软继推出DOS、Windows之后的又一个革命性的开发平台,其目的就是要搭建第三代互联网平台。文章对.Net的核心内容和组成进行了详细的介绍,并对其在地理信息服务领域的应用前景进行了展望。最后,基于.Net平台实现了一个提供地图服务的原型系统。     

一种基于GML实现互操作WebGIS的新机制

提出了一种基于GML实现互操作WebGIS的新机制。该机制以GML实现多源数据存储与传输为基础，利用WFS实现地理数据要素层存取、检索与更新，在客户端以SVG方式输出高质量矢量图形。与传统的WMS实现Web服务相比较，该机制能实时动态地实现异构、跨平台下地理数据要素层互操作。     

SVG矢量图形编辑器的设计与实现

本课题将基于SVG这一新的矢量图形标准,实现一种能够可视化绘制和编辑SVG图形的工具软件,可对图形对象进行平移、修改、缩放、删除等操作,并提供了图层工具,对于按照不同形式表现和管理的图形对象,进行图层操作。此外,笔者尝试进行了WebGIS方面的应用开发,使本系统能够满足小型地理信息系统的应用需求。     

基于SVG的空间数据的可视化

研究空间数据在SVG文档中如何进行数据组织及编码,实现地图数据到SVG图形的转换方法,并利用此方法完成校园地图的部分转换和基于此方法提出一个全新的Web GIS体系结构。     

地球空间Web服务数据交换机制的设计与实现

为了支持多源、异构的地球空间数据在互联网上异步、可靠的传输,基于开放地理信息Web服务体系（OWS）,提出了基于消息中间件的空间数据交换方法。首先分析了当前地球空间数据交换的研究现状及相关技术,指出了当前地球空间数据交换方式存在效率低等诸多方面的不足,特别是由于目前很多OWS实现都是基于HTTP的Web服务模式,服务之间的数据交换是无状态和不可靠的。其次介绍了消息中间件规范,设计了基于消息中间件的空间数据交换体系结构,并对该体系结构的各组成部分进行了详细阐述。最后基于Java消息服务（JMS）、Web要素服务（WFS）、Web坐标转换服务（WCTS）和Web制图服务（WMS）,实现了一个基于消息中间件的空间数据交换系统实例,验证了方法的可行性。     

WebGIS中异构数据源的集成

分析了多源GIS数据融合现状,探讨了WebGIS中异构空间数据源的集成问题,提出了一个以XML和GML为统一的数据表示格式,以SVG形式交互显示矢量地图的WebGIS体系结构。该体系结构既充分利用了现有网络和数据资源,具有良好的可扩展性。     

移动GIS中空间数据的可视化

分析了移动GIS应用中空间数据发布存在的问题,在分析SVG特性基础上,研究了基于SVG如何进行地图数据的组织,以及地图空间数据到SVG图形的转换方法,并给出了基于SVG的移动GIS实现框架及空间数据可视化的实现代码.     

A video streaming application for urban traffic management

Urban traffic control systems have based their technological infrastructure both on advanced analog close-circuit television systems (CCTV) and point-to-point links, providing difficult-to-scale and very expensive systems. The main goal of an urban traffic monitoring system is to capture, send, play and distribute video information from the streets of a certain city to a management centre where it is processed by different services. Current digitalization process of video networks, and the research carried out in the field of streaming media, has led vendors to present proprietary hardware and software solutions resulting in a strong dependency by their customers. This work presents an open urban traffic control system based in commercial off-the-shelf (COTS) philosophy for hardware and software components, as well as open source and standardized protocols. The existence of open standards for video encoding and protocols for streaming media transmission over IP networks has led to the proposal of such a system. The proposed system is a suitable solution in terms of scalability, cost, interoperability and performance for traffic control systems. Furthermore, its architecture can be easily adapted to other video applications and tools like command and control, surveillance or security systems for military and civilian applications.     

Sharing geospatial provenance in a service-oriented environment

One of the earliest investigations of provenance was inspired by applications in GIS in the early 1990’s. Provenance records the processing history of a data product. It provides an information context to help users determine the reliability of data products. Conventional provenance applications in GIS focus on provenance capture, representation, and usage in a stand-alone environment such as a desktop-based GIS software system. They cannot support wide sharing and open access of provenance in a distributed environment. The growth of service-oriented sharing and processing of geospatial data brings some new challenges in provenance-aware applications. One is how to share geospatial provenance in an interoperable way. This paper describes the development of provenance service for geospatial data products using the ebXML Registry Information Model (ebRIM) of a geospatial catalog service, which follows the interface specifications of the OGC Catalogue Services for the Web (CSW). This approach fits well the current service stack of the GIS domain and facilitates the management of geospatial data provenance in an open and distributed environment.     

基于Web Services的GIS多层体系结构研究

通过分析通用的Web Services架构和OWS技术体系结构，提出了一个基于Web Services的多层GIS组件体系结构，介绍了该结构的特点及各服务组件的功能。最后给出了该体系结构的一个实现技术方案，并详细分析和讨论了其中Web应用服务器、应用服务器及数据服务器三部分在设计与实现中关键技术的处理策略。     

基于SVG的实时Web GIS技术研究

web GIS是传统GIS发展的必然，目前有很多实现方法同样存在许多困难。本文讨论了当前Web GIS的发展态势以及面临的主要技术问题，详细分析了一种基于XML的矢量图形描述语言（SVG）的概念、它应用于Web GIS上的优点以及用于构建实时的web GIS的关键技术，并给出了一个应用实例。     

Understanding the role of licenses and evolution in open architecture software ecosystems

The role of software ecosystems in the development and evolution of open architecture systems whose components are subject to different licenses has received insufficient consideration. Such systems are composed of components potentially under two or more licenses, open source or proprietary or both, in an architecture in which evolution can occur by evolving existing components, replacing them, or refactoring. The software licenses of the components both facilitate and constrain the system's ecosystem and its evolution, and the licenses’ rights and obligations are crucial in producing an acceptable system. Consequently, software component licenses and the architectural composition of a system help to better define the software ecosystem niche in which a given system lies. Understanding and describing software ecosystem niches for open architecture systems is a key contribution of this work. An example open architecture software system that articulates different niches is employed to this end. We examine how the architecture and software component licenses of a composed system at design time, build time, and run time help determine the system's software ecosystem niche and provide insight and guidance for identifying and selecting potential evolutionary paths of system, architecture, and niches.     

基于SVG的Web绘图软件设计与实现

SVG是一种用XML描述二维矢量图形的开放标准的图形格式,其完全的DOM支持提供了与外界程序交互的标准接口。阐述了利用SVG技术设计Web绘图软件,实现直接通过浏览器绘制矢量图形的功能。图形数据可以保存在SQL Server数据库中,也可以保存为.SVG文件。     

基于XML的开放式WebGIS研究

首先对目前WebGIS中所存在的问题进行了深入分析,指出开放式WebGIS是今后发展的方向,并应用XML技术对开放式WebGIS所涉及的两个重要方面(数据互操作与功能互操作)进行了探讨和研究。在上述研究的基础上提出了一个完全基于XML的开放式WebGIS整体解决方案,并基于该方案设计,完成了一套原型系统。最后,利用该原型系统完成了几个对分布式异构地理空间数据进行集成处理的实验,验证了该方案的理论正确性和技术可行性。     

Will vector graphics finally make it on the Web?

Multimedia technology is an increasingly important part of the Web. Because of this, multimedia vendors are always looking for a competitive edge, as well as a better way to present content. And now, these vendors are looking closely at an important technology: scalable vector graphics (SVG). Currently, the Web mainly runs on bitmap-image formats like GIF (graphics interchange format), PNG (portable network graphics), and JPEG (designed by the Joint Photographic Experts Group). However, bitmap files can run large, even with data compression, and don't scale well. Vector-graphic formats don't experience these problems but never caught on because the technology consists of incompatible proprietary standards. The World Wide Web Consortium (W3C), though, may have eliminated this concern recently when it released an open SVG standard with broad industry support     

Web-GIS的设计与实现

地理信息系统要想有更大的发展,必须走开放式的道路。Ｗｅｂ－ＧＩＳ软件由于采用了当前主流的通信、应用协议和体系结构,大大增强了ＧＩＳ软件的开放性。该文主要从Ｗｅｂ－ＧＩＳ的特点、设计和实现的角度阐述了在开发Ｗｅｂ－ＧＩＳ中应考虑的各个要素,详细分析了Ｗｅｂ－ＧＩＳ的体系结构及其各种实现技术,并且提出了对今后发展的一些看法。     

基于SVG的网络数学图形编辑系统设计与实现

针对目前网上数学图形不能被查询和重用的弊端,提出了一种基于SVG的网络数学图形编辑系统的实现方案。该方案采用SVG技术实现,使得数学图形能够以不同于传统交流的方法在Web上处理和传输。文章分析了SVG和Ajax技术的特点,提出了基于SVG的网络数学图形编辑系统的体系结构,设计了一种基于关系数据库管理系统（RDBMS）的SVG存储方法,实现了在线编辑的图形创建、删除、保存、缩放、度量和计算等功能。     

基于SVG技术的考古探测WebGIS研究*

在传统考古领域中利用现代探测和信息技术辅助考古发掘,详细阐述了利用SVG技术和Java技术实现考古探测Web GIS的基本功能,包括地图的缩放、平移、查询以及交互等基本的GIS图层操作.首先介绍了SVG技术,分析了考古探测Web GIS的系统结构,研究了基于SVG技术的交互式图层管理,最后建立了系统的模拟结果.