Wireless sensor network nodes have only limited resources concerning memory and battery life-time. Mem- ory can be efficiently used by sharing data, and the life-time of a battery can be extended, when the node has lo...Wireless sensor network nodes have only limited resources concerning memory and battery life-time. Mem- ory can be efficiently used by sharing data, and the life-time of a battery can be extended, when the node has long power saving sleep-phases. We propose a publish/subscribe architecture that achieves these two aims. The results of our work are of great interest for sensor application developers, giving them now the opportu- nity to use our architecture for sharing data among different applications on the node as well as the different layers of the operating system. We introduce a blackboard which is used for centrally storing published val- ues, like measured data from a monitored sensor. This makes it possible to share stored data without monitoring the sensors once again, which is advantageously concerning power consumption, memory space, and reaction time. Beside the proposed publish/subscribe method for sensor nodes with its notification possibili- ties, our architecture fulfills also real-time requirements. We show how the well-known sensor operating system MANTIS OS can be extended by a real-time enabled, blackboard-based publish/subscribe architect- ture. This architecture and first of all its implementation is of special interest for cross layer optimization of sensor applications. Cross-layer approaches benefit from our architecture because the available implementa- tion can be used as an efficient framework for central storing and managing of shared values.展开更多
基于Blackboard平台数据库,研究设计了一种运行数据分析系统.在Blackboard网络教学平台中,用户的课程访问记录、测试使用情况、论坛使用情况可通过ACTIVITY_ACCUMULA-TOR、ATTEMPT、FORUM_MAIN等表的记录、计算后得到.所有数据从Blackbo...基于Blackboard平台数据库,研究设计了一种运行数据分析系统.在Blackboard网络教学平台中,用户的课程访问记录、测试使用情况、论坛使用情况可通过ACTIVITY_ACCUMULA-TOR、ATTEMPT、FORUM_MAIN等表的记录、计算后得到.所有数据从Blackboard平台数据库(ora-cle)导出到SQL Server数据库,再经过数据处理、汇总后,进行按课程汇总分析、按用户汇总分析、平台整体汇总分析.开发的数据分析系统利用SQL Server 2005对数据进行管理,易维护、扩展,数据传输和计算均在服务器端完成,增强了系统安全性和易维护性;采用Microsoft.NET MVC架构开发B/S网站,系统界面友好、简捷易操作.实际运行表明,Blackboard平台运行数据分析系统运行速度快、操作透明度高,对历史数据和准实时数据均能进行查询,结果准确.此系统已在实践中应用,并取得了良好效果.展开更多
文摘Wireless sensor network nodes have only limited resources concerning memory and battery life-time. Mem- ory can be efficiently used by sharing data, and the life-time of a battery can be extended, when the node has long power saving sleep-phases. We propose a publish/subscribe architecture that achieves these two aims. The results of our work are of great interest for sensor application developers, giving them now the opportu- nity to use our architecture for sharing data among different applications on the node as well as the different layers of the operating system. We introduce a blackboard which is used for centrally storing published val- ues, like measured data from a monitored sensor. This makes it possible to share stored data without monitoring the sensors once again, which is advantageously concerning power consumption, memory space, and reaction time. Beside the proposed publish/subscribe method for sensor nodes with its notification possibili- ties, our architecture fulfills also real-time requirements. We show how the well-known sensor operating system MANTIS OS can be extended by a real-time enabled, blackboard-based publish/subscribe architect- ture. This architecture and first of all its implementation is of special interest for cross layer optimization of sensor applications. Cross-layer approaches benefit from our architecture because the available implementa- tion can be used as an efficient framework for central storing and managing of shared values.
文摘基于Blackboard平台数据库,研究设计了一种运行数据分析系统.在Blackboard网络教学平台中,用户的课程访问记录、测试使用情况、论坛使用情况可通过ACTIVITY_ACCUMULA-TOR、ATTEMPT、FORUM_MAIN等表的记录、计算后得到.所有数据从Blackboard平台数据库(ora-cle)导出到SQL Server数据库,再经过数据处理、汇总后,进行按课程汇总分析、按用户汇总分析、平台整体汇总分析.开发的数据分析系统利用SQL Server 2005对数据进行管理,易维护、扩展,数据传输和计算均在服务器端完成,增强了系统安全性和易维护性;采用Microsoft.NET MVC架构开发B/S网站,系统界面友好、简捷易操作.实际运行表明,Blackboard平台运行数据分析系统运行速度快、操作透明度高,对历史数据和准实时数据均能进行查询,结果准确.此系统已在实践中应用,并取得了良好效果.
