Kiyohito Yoshihara

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Wireless sensor network monitoring is important for network maintenance, since it keeps the observer aware of node failures, resource depletion etc. Since communication overheads increase if the sink collects data individually from all sensor nodes, in-network data aggregation methods have been proposed which reduce the overheads. They form a routing tree(More)
The growth of Internet traffic has led to an increase in energy consumption by network equipment such as routers and switches. Consequently, energy consumption is becoming a key environmental, social, political and cost issue. Focusing on energy consumption by Internet Service Provider networks, the energy bottleneck is routers. Thus, it is imperative for(More)
In this paper, we propose an energy-efficient address allocation method for the event-driven sensor network, and implement and evaluate the proposed method. The proposed method allocates a temporary address only to a sensor node which detects an event, on an on-demand basis. By performing simulation studies, we evaluated the proposed method and compared it(More)
We investigate the power of a family of greedy algorithms for the independent set problem in cubic graphs and graphs of maximum degree three. These algorithm iteratively select vertices of minimum degree, but diier in the secondary rule for choosing among many candidates. We study three such algorithms, and prove tight performance ratios, with the best one(More)
This paper presents a system for the purpose of field deployment of nodes in wireless sensor networks. We propose a mobile phone based deployment adviser tool which is robust as well as practically implementable. The tool advises a layman deployer to create a optimized wireless sensor network by placing of the nodes according to application requirements.(More)
The scalability limitations of centralized management models have motivated distributed management models, in which management programs describing some of management tasks are distributed and executed on managed systems. In the models, management program distribution that considers dynamic network resource utilization is one of the most important(More)