Hajime Matsumura

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In this paper, we give a sufficient condition for a graph to have a degree bounded spanning tree. Let n ≥ 1, k ≥ 3, c ≥ 0 and G be an n-connected graph. Suppose that for every independent set S ⊆ V(G) of cardinality n(k − 1) + c + 2, there exists a vertex set X ⊆ S of cardinality k such that the degree sum of vertices in X is at least |V(G)| − c − 1. Then G(More)
We propose a method for improving motivation to participate in sensing services by presenting rankings in multidimensional hierarchical sets. We call this method <i>Top of Worlds</i>. Because previously proposed methods only rank a user among all other users, many have little chance of being ranked in the top group, resulting in little motivation to(More)
Dirac and Ore-type degree conditions are given for a bipartite graph to contain vertex disjoint cycles each of which contains a previously specified edge. This solves a conjecture of Wang in [6]. In this paper, we only consider finite undirected graphs without loops and multiple edges. For a vertex x of a graph G, the neighborhood of x in G is denoted by(More)
We propose an indexing method called UBI-Tree for improving the efficiency of a new type of data search called schema-less search. Schema-less search is a multi-dimensional range search from a wide variety of data, such as sensor data, collected through participatory sensing. Such data have different types and number of dimensions because a participant uses(More)
Although conjunctival squamous cell carcinoma is known to develop as a result of chronic irritation from wearing an ocular prosthesis, orbital sebaceous gland carcinoma arising in an anophthalmic pocket is extremely rare. We report a 68-year-old female who developed a sebaceous gland carcinoma 65 years after her right eye was enucleated (at the age of three(More)