Showing papers by "Takeshi Kubo published in 2011"
Patent•
14 Apr 2011
TL;DR: In this article, the problem of selecting a cluster head based on the variance of distances (hop number) from all the nodes in a cluster is solved, out of the cluster formed already.
Abstract: PROBLEM TO BE SOLVED: To select, as a cluster head, a node of which the variance of distances (hop number) from all the nodes in a cluster is lowest, out of the cluster formed already. SOLUTION: The node in the cluster formed in a network transmits hop information having a node ID, a cluster variable, the hop number from a start point, to other node. The node receives the hop information from the other node, records and increases the hop number within the received hop information by a fixed number, and the node transfers thereafter the hop information to the other node, calculates hop number variance information of own node, based on the recorded hop information, and transmits the hop number variance information of the own node, to the adjacent node. The node determines finally whether the own node is to be the cluster head or not, based on the hop number variance information of the own node and the hop number variance information transmitted from the adjacent node, and transmits a cluster head advertisement having the node ID of the own node to the other node, when the own node is determined to be the cluster head. COPYRIGHT: (C)2011,JPO&INPIT
2 citations
23 Mar 2011
TL;DR: A local interaction algorithm in a partial differential equation (or PDE) in a periodic pattern composed of sinusoidal waves is described and a new design method whereby a PDE is derived from a pattern of control values is proposed.
Abstract: In the near future, autonomous and distributed systems consisting of a huge number of sensor nodes are expected to play an important role. Due to their distributed nature, each node should control itself autonomously by means of a local interaction algorithm. Although such local interaction algorithms improve system scalability, how to design a local interaction algorithm has become an issue. In this paper, we describe a local interaction algorithm in a partial differential equation (or PDE) and propose a new design method whereby a PDE is derived from a pattern of control values. A pattern means a distribution of nodes’ control values over the network each of which is used to control the node. Nodes behave according to the pattern and as a result they collectively provide network functions such as collision and congestion avoidance. In this paper, we focus on a periodic pattern composed of sinusoidal waves and derive the PDE by exploiting the Fourier method.
2 citations
TL;DR: A lightweight method for determining the location of SIP message loss through relationships based on the SIP's retransmission mechanism is proposed and Numerical analyses show that the proposed method can locate the lossy links of Sip messages with a low probability of detection failure.
Abstract: The number of SIP-based services provided by network service providers (NSPs) is increasing. SIP allows NSPs to control services and to collect the information relating to charging for the usage of their customer communications. Monitoring SIP messages (exchanged between SIP proxy servers and user terminals) is vital for providing the stable SIP-based services. Monitoring SIP messages enables NSPs to quickly discover a fault location where SIP messages are lost, and to determine the subsequent recovery solutions. This paper proposes a lightweight method for determining the location of SIP message loss through relationships based on the SIP's retransmission mechanism. Numerical analyses show that the proposed method can locate the lossy links of SIP messages with a low probability of detection failure.
Patent•
14 Apr 2011
TL;DR: In this paper, the authors propose a solution to the problem of providing communication equipment for autonomously determining communications equipment for performing a predetermined function in a network such that the communication equipment is not gathered near one another.
Abstract: PROBLEM TO BE SOLVED: To provide communication equipment for autonomously determining communication equipment for performing a predetermined function in a network such that the communication equipment is not gathered near one another. SOLUTION: The communication equipment stores a first variable and a second variable showing the performance of a predetermined function, advertises the first variable to adjacent equipment, updates the first variable of its own equipment on the basis of a first variable advertized by the adjacent equipment and the first variable and the second variable of its own equipment, determines whether to move the performance of the predetermined function on the basis of the first variable of each adjacent equipment when performing the predetermined function, further determines adjacent equipment of a moving destination when moving the performance, notifies the determined adjacent equipment of the moving destination of the moving of the predetermined function, and updates the second value of its own equipment to a value showing that the predetermined function is not performed after the completion of moving of the predetermined function. COPYRIGHT: (C)2011,JPO&INPIT