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Satoshi Taoka

Bio: Satoshi Taoka is an academic researcher from Hiroshima University. The author has contributed to research in topics: Petri net & Bound graph. The author has an hindex of 7, co-authored 43 publications receiving 182 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the dynamic shortest path problem (DSPP) is defined, where an edge operation is an operation that increases or decreases an edge weight, and an edge operations are operations that add or delete an edge.
Abstract: An edge-weighted directed graph is referred to as a network in this paper, and an edge operation is an operation that increases or decreases an edge weight. Decreasing an edge weight from the infinite to a finite value or increasing any edge weight from a finite one to the infinite corresponds to addition or deletion of this edge, respectively. The dynamic shortest path problem (DSPP for short) is defined by "Given any network with a specified vertex (denoted as s), and any sequence of edge operations, construct a shortest path tree of each network obtained by executing those edge operations one by one in the order of the sequence." As an application, fast routing for an interior network using link state protocols, such as OSPF and IS-IS, requires solving DSPP efficiently. In this paper, among as many existing algorithms as possible, including those which execute several edge operations simultaneously, fundamental and/or important algorithms are implemented and their capability is evaluated based on the results of computational experiments.

17 citations

Proceedings ArticleDOI
20 May 2012
TL;DR: This paper considers MWVC with w(v) of any v of V being a positive integer, and five existing approximation algorithms are implemented, and they are evaluated through computing experiment.
Abstract: A vertex cover of a given graph G = (V, E) is a subset N of V such that N contains either u or v for any edge (u, v) of E. The minimum weight vertex cover problem (MWVC for short) is the problem of finding a vertex cover N of any given graph G = (V, E), with weight w(v) for each vertex v of V, such that the sum w(N) of w(v) over all v of N is minimum. In this paper, we consider MWVC with w(v) of any v of V being a positive integer. Five existing approximation algorithms are implemented, and they are evaluated through computing experiment.

13 citations

Proceedings ArticleDOI
03 May 1993
TL;DR: The 3-edge-connectivity augmentation problem for a specified set of vertices, where the graph can have multiple edges, is addressed and approximation algorithms are given.
Abstract: The 3-edge-connectivity augmentation problem for a specified set of vertices, where the graph can have multiple edges, is addressed. Both the weighted version, in which there may exist some distinct edge costs, and the unweighted version are treated. Approximation algorithms are given. >

11 citations

Book ChapterDOI
23 Jun 2003
TL;DR: In this paper, the authors proposed a heuristic algorithm FSDC for solving the maximum legal firing sequence problem of Petri nets (MAX LFS for short), which is improved from the existing one FSD by focusing on deadlock components, instead of D-siphons, and by incorporating efficient backtracking.
Abstract: The paper proposes a heuristic algorithm FSDC for solving the Maximum Legal Firing Sequence problem of Petri nets (MAX LFS for short) and evaluates it experimentally. FSDC is improved from the existing one FSD for MAX LFS by focusing on deadlock components, instead of D-siphons, and by incorporating efficient backtracking. As experimental evaluation, FSDC is applied to 3017 test problems to each of which existence of an exact solution is guaranteed, and it has produced an optimum solution to each of 2330 (77.2%) test problems, which is about 1.43 times more than that of FSD, while the average CPU time is about 1.82 times longer than that of FSD. For five related problems each of which contains MAX LFS as a subproblem, it is experimentally shown that incorporating FSDC for solving MAX LFS gives us five heuristic algorithms that are superior in capability to existing ones.

10 citations


Cited by
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Journal Article
TL;DR: In this article, a new algorithm for maximum weighted matching in general edge-weighted graphs is presented, which calculates a matching with an edge weight of at least one-half of the edge weight for a maximum weighted match.
Abstract: A new approximation algorithm for maximum weighted matching in general edge-weighted graphs is presented. It calculates a matching with an edge weight of at least of the edge weight of a maximum weighted matching. Its time complexity is O(|E|), with |E| being the number of edges in the graph. This improves over the previously known -approximation algorithms for maximum weighted matching which require O(|E| log(|V|)) steps, where |V| is the number of vertices.

197 citations

01 Jul 2008
TL;DR: An exact algorithm is proposed for the maximum weight clique problem, which is faster than Ostergard's algorithm in case the graph is dense, and the efficiency of this algorithm is shown with some experimental results.
Abstract: Given an undirected graph with weight for each vertex, the maximum weight clique problem is to find the clique of the maximum weight. Ostergard proposed a fast exact algorithm for solving this problem. We show his algorithm is not efficient for very dense graphs. We propose an exact algorithm for the problem, which is faster than Ostergard’s algorithm in case the graph is dense. We show the efficiency of our algorithm with some experimental results.

72 citations

Journal ArticleDOI
TL;DR: The state-of-the-art siphon theory of Petri nets is surveyed including basic concepts, computation of siphons, controllability conditions, and deadlock control policies based on siphons.

62 citations

Journal ArticleDOI
TL;DR: This paper characterize three main components in establishing network survivability for an existing network, namely, determining network connectivity, augmenting the network, and finding disjoint paths.
Abstract: Network survivability--the ability to maintain operation when one or a few network components fail--is indispensable for present-day networks. In this paper, we characterize three main components in establishing network survivability for an existing network, namely, (1) determining network connectivity, (2) augmenting the network, and (3) finding disjoint paths. We present a concise overview of network survivability algorithms, where we focus on presenting a few polynomial-time algorithms that could be implemented by practitioners and give references to more involved algorithms.

62 citations

Journal ArticleDOI
TL;DR: Experimental results show that the algorithm outperforms all the previously known linear-time algorithms for 3-edge-connectivity in determining if a given graph is 3- Edge-connected and in determining cut-pairs and its performance is also among the best in determining the 3- edge-connected components.

52 citations