Tsunehiko Kameda

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In anonymous networks, the processors do not have identity numbers. We investigate the following representative problems on anonymous networks: (a) the leader election problem, (b) the edge election problem, (c) the spanning tree construction problem, and (d) the topology recognition problem. On a given network, the above problems may or may not be(More)
In anonymous networks, the processors do not have identity numbers. In Part I of this paper, we characterized the classes of networks on which some representative distributed computation problems are solvable under different conditions. A new graph property called symmetricity played a central role in our analysis of anonymous networks. In Part I I , we(More)
The problem of searching for mobile intruders in a polygonal region by mobile searchers is considered. A searcher can move continuously inside a polygon holding a flashlight that emits a single ray of light whose direction can be changed continuously. The vision of a searcher at any time instant is limited to the points on the ray. The intruders can move(More)
Let a distributed system be represented by a graphG=(V, E), whereV is the set of nodes andE is the set of communication links. A coterie is defined as a family,C, of subsets ofV such that any pair of subsets inC has at least one node in common and no subset inC contains any other subset inC. Assuming that each nodev i ∈V (resp. linke j ∈E) is operational(More)
Polygon search is the problem of finding mobile intruders who move unpredictably in a polygonal region. In this paper, we consider a special case of this problem, called boundary search, where the searcher is allowed to move only along the boundary of the polygon. We concentrate on a single searcher with one flashlight (called a 1-searcher), but it is known(More)
An arbitrary m×n Boolean matrix M can be decomposed exactly as M = UοV, where U (resp. V) is an m×k (resp. k ×n) Boolean matrix and ο denotes the Boolean matrix multiplication operator. We first prove an exact formula for the Boolean matrix J such that M = MοJT holds, where J is maximal in the sense that if any 0(More)