摘要：
Caching is the key technology for Mobile Database. In the mobile computing environment, how to guarantee the data in local cache is consistent with the primary copy on the server is the chief consideration in this paper. An improved cache invalidation schema based on Mobile Agent is designed. The proposed schema uses asynchronous invalidation method and the Control Message broadcasted by MSS periodically. MSS maintains for each MC a data structure which stores the latest timestamp for each data item cached by MC. In contract with the traditional cache invalidation algorithm, the analysis and the experimental results show that the improved schema is efficient.
会议名称：
2009 International Forum on Computer Science-Technology and Applications(2009年国际计算机科学技术与应用论坛 IFCSTA 2009)
会议时间：
2009-12-25
会议地点：
重庆
会议论文集名称：
2009 International Forum on Computer Science-Technology and Applications(2009年国际计算机科学技术与应用论坛 IFCSTA 2009)论文集
关键词：
data aggregation;ant colony algorithm;Wireless sensor network
摘要：
A wireless sensor network consists of a large number of sensor nodes scattered in the region of the network which have limited energy and limited computational and sensing ability. Data aggregation is important in this kind of network which can make use of the energy of the sensor nodes efficiently, and reduce the traffic in network by utilizing the abilities of the nodes in local computation and storage. Ant Colony Algorithm is a paradigm for designing meta heuristic algorithm for combinatorial optimization problems. An improved Ant Colony Algorithm is studied and applied it into data aggregation in Wireless Sensor Network for a group of source nodes to send data to a single sink node. Moreover, Dijkstra Algorithm is introduced in computing the hop counts for all the nodes to the sink node. Simulation has shown that the amounts of pheromone on the optimal path increase faster than others. At last, we can get the global optimal path.
摘要：
In most sensor network applications, the information gathered by sensors will be meaningless without the location of the sensor nodes. Node localization has been a topic of active research in recent years. Accurate self-localization capability is highly desirable in wireless sensor network (WSN). This paper proposes a genetic simulated annealing algorithm based localization (GSAAL) algorithm for WSN. The proposed algorithm adopts two new genetic operators: single-vertex- neighborhood mutation and the descend-based arithmetic crossover. Four example problems are used to evaluate the performance of the proposed algorithm. Simulation results show that our algorithm can achieve higher accurate position estimation than semi-definite programming with gradient search localization (SDPL).
期刊：
ICNC 2008: FOURTH INTERNATIONAL CONFERENCE ON NATURAL COMPUTATION, VOL 1, PROCEEDINGS,2008年:608-613
通讯作者：
Zhang, Qingguo
作者机构：
[Zhang, Qingguo; Jin, Cong; Ye, Junmin; Zhang, Wei; Ma, Changlin; Wang, Jinghua] Huazhong Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, Qingguo] H;Huazhong Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.
摘要：
In most sensor network applications, the information gathered by sensors will be meaningless without the location of the sensor nodes. Node localization has been a topic of active research in recent years. Accurate self-localization capability is highly desirable in wireless sensor network. This paper proposes a genetic algorithm based localization(GAL). The proposed genetic algorithm adopts two new genetic operators: single-vertex-neighborhood mutation and the descend-based arithmetic crossover. Four example problems are used to evaluate the performance of the proposed algorithm. Simulation results show that our algorithm can achieve higher accurate position estimation than semi-definite programming with gradient search localization (SDPL) [11] and simulated annealing based localization (SAL)[13]. Compared to the usual crossover operator: simple arithmetic crossover, whole arithmetic crossover and single-point crossover, the proposed crossover can obtain a lower mean position error.
摘要：
In most sensor network applications, the information gathered by sensors will be meaningless without the location of the sensor nodes. Node localization has been a topic of active research in recent years. Accurate self-localization capability is highly desirable in wireless sensor network (WSN). This paper proposes a new centralized localization algorithm for WSN. Given the distances between a sensor and its a few 1-hop neighbors, the proposed algorithm can estimate the sensor's position with genetic algorithm(GA). The sensor doesn't have to neighbor to anchors. The localization accuracy is very high. Four example problems are used to evaluate the performance of the proposed algorithm. Simulation results show that our algorithm can achieve higher accurate position estimation than semi-definite programming with gradient search localization (SDPL) [11] and simulated annealing based localization (SAL)[13].
