中间件技术在地震信息系统中的应用

中间件技术屏蔽了底层分布式环境的复杂性和异构性,简化了分布式应用程序的开发,使分布式应用程序的健壮性、可扩展性、可用性更好。介绍了面向对象中间件、面向消息中间件、面向大规模分布式系统中间件、服务质量中间件等当前各种中间件技术发展的现状,分析了中间件技术的原理、种类及在地震信息系统中的应用,提出了中间件技术研究的几个发展趋势,即网格技术、面向移动计算、面向服务质量等。     

GDAL多源空间数据访问中间件

空间数据多存储格式的特点给数据共享和互操作带来困难,往往成为数据动态集成应用中的瓶颈。实际应用中迫切需要一个能够随时、动态,并可与应用程序紧密集成的转换工具。本文提出采用中间件形式设计上述工具,并基于GDAL库实现了该工具,完成了多源空间数据访问功能,改善了应用系统的动态集成性能,并通过应用验证了所提出方法的有效性。     

Navigating through SPASE to heliospheric and magnetospheric data

Virtual observatories have been introduced by the astrophysics community as an environment connecting distributed data sources with a unified interface. The heliophysics community soon recognized that they faced a similar problem of many distributed data sets with varying amount of information about them and several discipline specific virtual observatories have been established. Two of them, the virtual heliospheric observatory (VHO) and the virtual magnetospheric observatory (VMO), share a common architecture design with development efforts oriented towards a structured data search. This paper describes the VHO/VMO middleware and its components from metadata preparation and processing to the user interface.     

GIS与SCADA集成技术的研究与应用

针对GIS与电网SCADA一体化集成过程中存在的功能模块整合与数据共享问题,设计了系统一体化数据模型,建立SCADA主动实时数据库,并采用COM、数据库与中间件技术,基于ArcEngine与.Net平台开发并实现了集成系统的相关功能模块。实践表明,一体化数据库的建立不仅实现了地理数据与采集数据的无缝连接与共享,也保证了数据的一致性和系统的实时性。     

浅析网络地理信息系统WebGIS的构建技术

WebGIS是地理信息系统与Internet技术相结合的产物,是当前地理信息系统应用和研究热点。本文阐述了WebGIS的特点,介绍了目前实现WebGIS系统的几种构建模型、实现方法及其数据的管理和组织,并进行了详细的分析和比较。     

网格GIS中的GML语言技术与设计框架

基于网格技术的地理信息系统的研究与开发 ,将改变传统 GIS系统的应用模式与计算能力 ,使 GIS转变为以服务为中心 ,提供一体化的空间信息应用服务的智能化信息平台。而 Grid GML(Grid Geographic Markup L an-guage)将是网格 GIS的交流与对话语言 ,为网格 GIS的中间件之间、智能体之间、系统之间及系统内部的空间信息传输、存储与通信等提供了可能。本文在 XML 技术、网格体系结构技术及 OGC的 GML3标准的基础上对Grid GML 进行了详细的分析与设计。     

网格GIS及其关键技术

网格计算和中间件技术在GIS软件中的实现给GIS带来了新的发展,WebGIS实现了数据的分布性,而基于中间件的网格GIS的目标是实现GIS数据和GIS功能服务的分布性。文中从分析当前WebGIS的不足入手,阐述了网格GIS的特性,以及在构建网格GIS过程中所应用的关键技术问题。网格计算技术为网格GIS提供了高速、高效的网络环境,同时中间件技术使得GIS向用户提供功能和资源服务成为可能,网格GIS中数据传输与通信是通过GMI,语言、Web services等来实现,文章最后提出了网格GIS的功能结构模型。     

WEB-IS (integrated system): an overall view

WEB-IS, Web-based Integrated System, allows remote, interactive visualization of large-scale 3-D data over the Internet, along with data analysis and data mining. In this paper, we discuss the overall structure of WEB-IS. Up until now we have developed three sub-modules geared towards geophysical problems. WEB-IS1 allows geoscientists to navigate through their 3-D geophysical data, such as seismic structures or numerical simulations, and interactively analyze the statistics or apply data-mining techniques, such as cluster analysis. WEB-IS2 lets a user control Amira (a powerful 3-D visualization package) remotely and analyze, render and view large datasets across the Internet. WEB-IS3 is an imaging service that enables the user to control the scale of features to view through interactive zooming. In the near future, we propose to integrate the three components together through a middleware framework called NaradaBrokering (iNtegrated Asynchronous Real-time Adaptive Distributed Architecture, a distributed messaging infrastructure that can be used to intelligently route data between the originators and registered consumers) without regard for time or location. As a result, WEB-IS will improve its scalability and acquire properties of fault-tolerance. WEB-IS uses a combination of Java, C++, and through the use of NaradaBrokering will seamlessly integrate the server-side processing and user interaction utilities on the client. The server takes care of the processor intensive tasks, such as visualization and data mining, and sends either the resulting bitmap image or statistical results to the middleware across the Internet for viewing. WEB-IS is an easy-to-use service, which will eventually help geoscientists collaborate from different sites in a natural manner. It will be very useful in the next 10 years because of the increasing number of space missions and geophysical campaigns.     

网格GIS的应用架构及关键技术

本文以网格计算在 GIS的应用为主线 ,分析阐述了当前网格计算在 GIS领域中的应用及其所面临的主要问题 ,结合中间件技术 ,给出了网格 GIS的应用架构 ,并列举了所需的几项关键技术。特别就当前 GIS所面临的共性问题进行了分析 ,根据软件可重用原理 ,在分析现有网格技术发展的基础上 ,指出了基于 GML语言应用 WebService技术的中间件分布式架构是 GIS软件发展的一个主要方向及解决当前 GIS领域中所存在问题的最佳方式 ,并讨论了其实现过程。