最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。
4.2.1. What is W3C? ¶
W3C refers to World wide Web Consortium (World Wide Web Consortium)
W3C was founded in October 1994
W3C is created by Tim Berners-Lee
W3C is a member organization
The work of the W3C is to standardize web
W3C creates and maintains WWW standards
W3C standard is called W3C recommendation (W3C specification)
4.2.2. How was the W3C created? ¶
The World wide Web was developed as a project of CERN, where Tim Berners-Lee developed the prototype of the World wide Web.
Tim Berners-Lee, the inventor of the World wide Web, is currently the director of the World wide Web Alliance.
The W3C was created in 1994 to complete collaboration between the Massachusetts Institute of Technology (MIT) and the European Institute of Particle Physics (CERN) with the support of the Defense Advanced Research projects Agency (DARPA) and the European Commission (European Commission).
4.2.3. Standardized web ¶
The W3C is committed to making web available to all users (regardless of their educational background, ability, financial resources and physical disability).
The W3C also works with other standardization organizations, such as the Internet Engineering working Group (Internet Engineering Task Force), the Wireless Application Protocol (WAP) and the Unicode Alliance (Unicode Consortium).
The W3C is jointly operated by the computer Science and artificial Intelligence Laboratory of the Massachusetts Institute of Technology (MIT CSAIL), the European Union for Research in Information Mathematics (ERCIM) headquartered in France and Keio University (Keio University) in Japan, and has branch offices around the world.
4.2.4. W3C members ¶
Precisely because Web is so important (both in terms of its reach and investment) that it should not be controlled by any single organization, theW3C plays the role of a member organization:
Some well-known members include:
IBM
Microsoft
America Online
Apple
Adobe
Macromedia
Sun Microsystems
Members of W3C including: Software developers, content providers, enterprise users, communication companies, research institutions, research laboratories, standardization groups, and governments.
4.2.5. W3C Recommendations ¶
The W3C’s most important work is to develop Web specifications (called recommendations, Recommendations), which describe Web’s communication protocols (such as HTML and XHTML) and other building blocks.
Each development recommended by the W3C is done through a working group of members and invited experts. The working group is funded by companies and other organizations and will create a working draft followed by a proposal recommendation. In general, recommendations are submitted to W3C members and directors in order to obtain formal approval.
In the next section, we will explain the specification approval process for you.