Kouji Miura

A user customized selection and categorization for broadcast data

Recently, many broadcast satellites have been launched to provide data broadcasting services for public users. Although the provided services can cover many kinds of data and a wide range of user interest, it is considered that, in general, a user is interested in only some specific genres of data. Consequently, storing all received data is considered to be inefficient and only wasting a large amount of memory. This motivated us to introduce an information filtering system into a broadcast data receiving system. The use of filtering system increases the efficiency of memory usage and reduces time for searching interesting data. In this paper, we propose a filtering method that uses a tree structure to represent user preferences. The use of this filtering method enable the receiving system to select only data that match users interest and classify the stored data in the way that suits the users access pattern. We also describe the design and implementation of our broadcast data. Receiving system that makes use of the proposed filtering method. Further, we evaluate the performance of our method by showing some simulation results.

A distributed shortest‐paths algorithm with distance‐dependent message complexities

This paper presents a distributed algorithm for the single-source shortest-paths problem in a network with nonnegative integral link weights. Its message complexity is , where n is the number of processors, e is the number of links, and D is the maximum distance from the root. The known shortest-paths algorithm with the distance-dependent message complexity requires O(min(Dn + e, n2)) messages. The algorithm of this paper is more efficient for networks with D = o(n3/e) and D = ω(e/n). Moreover, the breadth-first search tree problem is considered.