Shinji Motegi

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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)
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)
Personal healthcare is a promising market of a personal area network (PAN). The PAN consists of a data collector and multiple wearable sensors which must send data to the collector according to the frequency specified by each PAN. The data collector may be any hand-held or portable device, e.g., a mobile phone, a PDA, or a wristwatch. An individual user(More)
Towards the wide acceptance of ubiquitous networking, practical and deployable ubiquitous applications must be provided in a concrete and easily understandable form to end-users. We designed and implemented ubiquitous nodes, KDDI Ubiquitous Bit (kubit). The highest priority was given to application-oriented design and ease of deployment in a typical home(More)
In addition to blog and schedule sharing, sharing physical data, such as noise or temperature values, and event data, such as information recorded when purchasing at a shop, with other nodes located in a distributed manner enables new applications using geographic distribution. Geographic distribution of physical data of noise allows a user to see(More)
Mobile phones have great potential to act as global mobile sensing devices due to already being equipped with sensors, e.g., sound, image and acceleration sensors. People as individuals or special interest groups can apply the new sensing devices to form sensing networks called people-centric sensing networks that sense what we are doing and support our(More)
In this poster, we propose a new tool, i.e. a node placement adviser, which supports deployment workers of sensor networks. The adviser tool is realized in the form of mobile terminal software and acts as a proxy of an additional node, as well as communicating with those already placed. Based on the communication results, it indicates how favorable the(More)
Most sensor nodes usually have the ability to vary their own wireless transmission power. Hence they have the potential to control the network topology, which is the pattern of links connecting pairs of nodes in a network. In this paper, we propose a connectivity ascertainment based distributed topology control algorithm. The algorithm draws out the(More)