来自不同传感器网络的流数据共享和集成对于带动相关业务和行业的创新具有重要意义.现有的传感网络往往是任务导向或领域专用的,仅适用于特定的应用场景,难以有效地在不同应用间共享和重用其数据资源.传感流数据的服务化是一种有效解决...来自不同传感器网络的流数据共享和集成对于带动相关业务和行业的创新具有重要意义.现有的传感网络往往是任务导向或领域专用的,仅适用于特定的应用场景,难以有效地在不同应用间共享和重用其数据资源.传感流数据的服务化是一种有效解决物理传感网络数据资源共享和重用的方法.针对已有服务化方法在应对大规模传感流数据共享和用户并发访问方面存在的局限性,该文提出了一种面向传感流数据的服务化封装方法——SDaaS(Stream Data as a Service),该方法使用事件的方式驱动传感流数据的处理和传输,通过对传感数据的融合操作实现服务对传感流数据的深层次加工,并基于Pub/Sub机制实现传感流数据的按需分发.文中基于Spark Streaming实现对大规模流数据加工操作的封装,并通过对传统的基于匹配树的事件匹配算法进行改进实现了高效的流数据内容分发,以保障将传感数据实时的分发给相应需求.该文通过实验验证了流数据服务的性能,印证了流数据服务能够响应不同的数据需求,在毫秒级别将数据流分发给不同应用.展开更多
With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependenc...With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.展开更多
Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side prog...Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system.展开更多
文摘来自不同传感器网络的流数据共享和集成对于带动相关业务和行业的创新具有重要意义.现有的传感网络往往是任务导向或领域专用的,仅适用于特定的应用场景,难以有效地在不同应用间共享和重用其数据资源.传感流数据的服务化是一种有效解决物理传感网络数据资源共享和重用的方法.针对已有服务化方法在应对大规模传感流数据共享和用户并发访问方面存在的局限性,该文提出了一种面向传感流数据的服务化封装方法——SDaaS(Stream Data as a Service),该方法使用事件的方式驱动传感流数据的处理和传输,通过对传感数据的融合操作实现服务对传感流数据的深层次加工,并基于Pub/Sub机制实现传感流数据的按需分发.文中基于Spark Streaming实现对大规模流数据加工操作的封装,并通过对传统的基于匹配树的事件匹配算法进行改进实现了高效的流数据内容分发,以保障将传感数据实时的分发给相应需求.该文通过实验验证了流数据服务的性能,印证了流数据服务能够响应不同的数据需求,在毫秒级别将数据流分发给不同应用.
基金supported by the National Natural Science Foundation of China (No. 61502043, No. 61132001)Beijing Natural Science Foundation (No. 4162042)BeiJing Talents Fund (No. 2015000020124G082)
文摘With the growing popularity of data-intensive services on the Internet, the traditional process-centric model for business process meets challenges due to the lack of abilities to describe data semantics and dependencies, resulting in the inflexibility of the design and implement for the processes. This paper proposes a novel data-aware business process model which is able to describe both explicit control flow and implicit data flow. Data model with dependencies which are formulated by Linear-time Temporal Logic(LTL) is presented, and their satisfiability is validated by an automaton-based model checking algorithm. Data dependencies are fully considered in modeling phase, which helps to improve the efficiency and reliability of programming during developing phase. Finally, a prototype system based on j BPM for data-aware workflow is designed using such model, and has been deployed to Beijing Kingfore heating management system to validate the flexibility, efficacy and convenience of our approach for massive coding and large-scale system management in reality.
文摘Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system.
