Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web bas...Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web based applications. The mechanism incorporates the eXtensible Markup Language （XML） and Hierarchical Data Format （HDF） to provide a flexible and efficient data format. Heterogeneous transfer data is classified into light and heavy data, which are stored using XML and HDF respectively; the HDF data format is then mapped to Java Document Object Model （JDOM） objects in XML in the Java environment. These JDOM data objects are sent across computer networks with the support of the Java Remote Method Invocation （RMI） data transfer infrastructure. Client＇s defined data priority levels are implemented in RMI, which guides a server to transfer data objects at different priorities. A remote monitoring system for an industrial reactor process simulator is used as a case study to illustrate the proposed data transfer mechanism.展开更多
比较飞行员对平显(Head Up D isp lay,HUD)地空数传指令各种显示方案的认知操作效果和使用评价意见,在此基础上提出新型歼击机HUD地空数传指令显示的建议方案。实验采用2×2×2重复测量设计,以151名空军现役歼击机飞行员为实验...比较飞行员对平显(Head Up D isp lay,HUD)地空数传指令各种显示方案的认知操作效果和使用评价意见,在此基础上提出新型歼击机HUD地空数传指令显示的建议方案。实验采用2×2×2重复测量设计,以151名空军现役歼击机飞行员为实验对象,完成HUD地空数传指令不同显示方案共8幅画面的测试,并在实验结束后对每种显示方案做出“优、良、中、差”的等级评定。根据工效学实验的结果数据和飞行员的使用性评价意见,提出新型歼击机HUD数传指令显示的优化方案。展开更多
空间数据交换标准是国家空间数据基础设施的一个重要组成部分,也是目前实现空间数据共享的一个必要手段.文中在分析OGC制定的基于XM L的地理空间数据编码标准的执行规范GM L 3.1和我国地球空间数据交换格式的基础上,定义了顾及中国地球...空间数据交换标准是国家空间数据基础设施的一个重要组成部分,也是目前实现空间数据共享的一个必要手段.文中在分析OGC制定的基于XM L的地理空间数据编码标准的执行规范GM L 3.1和我国地球空间数据交换格式的基础上,定义了顾及中国地球空间数据交换格式的GM L 3.1模式——CGM L,给出了CGM L的框架,对其各个模式进行了论述,并设计了一个基于CGM L的应用模式.展开更多
Geo-Spatial Data Transfer Standard is an important part of 'National Spatial Data Infrastructure(NSDI)' ,as well as a necessary means for data sharing. 'Chinese National Geo-Spatial Data Transfer Format (C...Geo-Spatial Data Transfer Standard is an important part of 'National Spatial Data Infrastructure(NSDI)' ,as well as a necessary means for data sharing. 'Chinese National Geo-Spatial Data Transfer Format (CNSDTF)' was approved by National Quality Technology Supervise Bureau in 1999 with the standard serial number of 17798-1999. It is designed to support vector and raster spatial data. This paper describes the vector part of CNSDTF, including design ideas, main characters, conceptual model, definition of spatial object, and file structure.展开更多
文摘Efficient real time data exchange over the Internet plays a crucial role in the successful application of web-based systems. In this paper, a data transfer mechanism over the Internet is proposed for real time web based applications. The mechanism incorporates the eXtensible Markup Language （XML） and Hierarchical Data Format （HDF） to provide a flexible and efficient data format. Heterogeneous transfer data is classified into light and heavy data, which are stored using XML and HDF respectively; the HDF data format is then mapped to Java Document Object Model （JDOM） objects in XML in the Java environment. These JDOM data objects are sent across computer networks with the support of the Java Remote Method Invocation （RMI） data transfer infrastructure. Client＇s defined data priority levels are implemented in RMI, which guides a server to transfer data objects at different priorities. A remote monitoring system for an industrial reactor process simulator is used as a case study to illustrate the proposed data transfer mechanism.
文摘比较飞行员对平显(Head Up D isp lay,HUD)地空数传指令各种显示方案的认知操作效果和使用评价意见,在此基础上提出新型歼击机HUD地空数传指令显示的建议方案。实验采用2×2×2重复测量设计,以151名空军现役歼击机飞行员为实验对象,完成HUD地空数传指令不同显示方案共8幅画面的测试,并在实验结束后对每种显示方案做出“优、良、中、差”的等级评定。根据工效学实验的结果数据和飞行员的使用性评价意见,提出新型歼击机HUD数传指令显示的优化方案。
文摘空间数据交换标准是国家空间数据基础设施的一个重要组成部分,也是目前实现空间数据共享的一个必要手段.文中在分析OGC制定的基于XM L的地理空间数据编码标准的执行规范GM L 3.1和我国地球空间数据交换格式的基础上,定义了顾及中国地球空间数据交换格式的GM L 3.1模式——CGM L,给出了CGM L的框架,对其各个模式进行了论述,并设计了一个基于CGM L的应用模式.
基金Project supported by the National Outstanding Youth Researchers Foundation(No.49525101)
文摘Geo-Spatial Data Transfer Standard is an important part of 'National Spatial Data Infrastructure(NSDI)' ,as well as a necessary means for data sharing. 'Chinese National Geo-Spatial Data Transfer Format (CNSDTF)' was approved by National Quality Technology Supervise Bureau in 1999 with the standard serial number of 17798-1999. It is designed to support vector and raster spatial data. This paper describes the vector part of CNSDTF, including design ideas, main characters, conceptual model, definition of spatial object, and file structure.
