门户环境中基于语义数据协作应用集成方法

目前,门户的功能定位已经从传统的信息集成转向应用集成.门户环境中应用间的进一步集成实际上表现为Portlet互操作问题. 现有Portlet互操作方法在共享范围、标准兼容方面存在不足且难于集成已有应用系统.提出了一种基于语义数据协作的Portlet互操作方法,其基本思想是:将参与互操作的Portlet抽象为ShadowComponent组件,然后基于本体建立ShadowComponent之间的语义数据关联,并使用ECA(event-condition- action)规则实现Portlet互操作.实验证明,该方法无须对已有应用作任何修改即可完成门户中的应用集成.

A Semantic Data Coordination Based Approach for Application Integration in Portals

When used with satellite links, traditional TCP suffers from a number of performance problems, especially for higher propagation delay, bit error rate, asymmetrical bandwidth and signal attenuation due to rain. A new active proxy without breaking TCP semantic is proposed to improve TCP performance of satellite network. The congestion control algorithm in the proxy sets the window size according to the measurement information on bandwidth changes from the two probe packet pairs with different priorities. A stability analysis of the hybrid proxy system is performed. The loss recovery based on selective negative acknowledgement (SNACK) can work even if the clocks is not synchronized. The results demonstrate that proxy in combination with SNACK allows TCP to fully exploit the possible throughput of the satellite network.