PEADG(Power Efficient Algorithm for Data Gathering)协议是基于WSN的抄表系统数据收集协议,PEADG协议建立的网络拓扑结构由多棵树组成,树根节点分担了网络负载,较好地延长了网络生命期,但PEADG协议仍然存在一些问题,如:没有考虑多棵...PEADG(Power Efficient Algorithm for Data Gathering)协议是基于WSN的抄表系统数据收集协议,PEADG协议建立的网络拓扑结构由多棵树组成,树根节点分担了网络负载,较好地延长了网络生命期,但PEADG协议仍然存在一些问题,如:没有考虑多棵树上节点个数的平衡等。针对协议中存在的问题,提出了三方面的改进:①平衡了拓扑结构中多棵树的网络负载;②增加了对节点剩余能量的考虑;③利用基站收集了网络拓扑信息。利用MATLAB工具对改进后的协议进行了仿真,结果表明改进后的协议延长了网络的生命期。展开更多
Cooperative distributed system covers a wide range of applications such as the systems for industrial controlling and business-to-business trading, which are usually safety-critical. Coordinated exception handling （...Cooperative distributed system covers a wide range of applications such as the systems for industrial controlling and business-to-business trading, which are usually safety-critical. Coordinated exception handling （CEH） refers to exception handling in the cooperative distributed systems, where exceptions raised on a peer should be dealt with by all relevant peers in a consistent manner. Some CEH algorithms have been proposed. A crucial problem in using these algorithms is how to develop the peers which are guaranteed coherent in both normal execution and exceptional execution. Straightforward testing or model checking is very expensive. In this paper, we propose an effective way to rigorously develop the systems with correct CEH behavior. Firstly, we formalize the CEH algorithm by proposing a Peer Process Language to precisely describe the distributed systems and their operational semantics. Then we dig out a set of syntactic conditions, and prove its sufficiency for system coherence. Finally~ we propose a global-to-local approach, including a language describing the distributed systems from a global perspective and a projection algorithm, for developing the systems. Given a well-formed global description, a set of peers can be generated automatically. We prove the system composed of these peers satisfies the conditions, that is, it is always coherent and correct for CEH.展开更多
文摘PEADG(Power Efficient Algorithm for Data Gathering)协议是基于WSN的抄表系统数据收集协议,PEADG协议建立的网络拓扑结构由多棵树组成,树根节点分担了网络负载,较好地延长了网络生命期,但PEADG协议仍然存在一些问题,如:没有考虑多棵树上节点个数的平衡等。针对协议中存在的问题,提出了三方面的改进:①平衡了拓扑结构中多棵树的网络负载;②增加了对节点剩余能量的考虑;③利用基站收集了网络拓扑信息。利用MATLAB工具对改进后的协议进行了仿真,结果表明改进后的协议延长了网络的生命期。
基金supported by the National Natural Science Foundation of China under Grant Nos. 90718002 and 60573161
文摘Cooperative distributed system covers a wide range of applications such as the systems for industrial controlling and business-to-business trading, which are usually safety-critical. Coordinated exception handling （CEH） refers to exception handling in the cooperative distributed systems, where exceptions raised on a peer should be dealt with by all relevant peers in a consistent manner. Some CEH algorithms have been proposed. A crucial problem in using these algorithms is how to develop the peers which are guaranteed coherent in both normal execution and exceptional execution. Straightforward testing or model checking is very expensive. In this paper, we propose an effective way to rigorously develop the systems with correct CEH behavior. Firstly, we formalize the CEH algorithm by proposing a Peer Process Language to precisely describe the distributed systems and their operational semantics. Then we dig out a set of syntactic conditions, and prove its sufficiency for system coherence. Finally~ we propose a global-to-local approach, including a language describing the distributed systems from a global perspective and a projection algorithm, for developing the systems. Given a well-formed global description, a set of peers can be generated automatically. We prove the system composed of these peers satisfies the conditions, that is, it is always coherent and correct for CEH.
