Tetsuo Asano, Hisao Tamaki, Naoki Katoh, Takeshi Tokuyama
Voronoi diagram for a set of geometric objects is a partition of the plane (or space in higher dimensions) into disjoint regions each dominated by some given object under a predetermined criterion....
Geometry © 1998 Springer-Verlag New York Inc. How to Cut Pseudoparabolas into Segments (2008)
Hisao Tamaki, Takeshi Tokuyama
Abstract. LetƔ be a collection of unbounded x-monotone Jordan arcs intersecting at most twice each other, which we call pseudoparabolas, since two axis parallel parabolas intersect at most twice. We...
Akiko Suzuki, Takeshi Tokuyama
We consider the weighted dense subgraph problem (often called the maximum dispersion problem or dense k-subgraph problem) defined as follows: Consider a weighted graph G =(V,E), where |V | = n and...
: www.idealibrary.com on Mining Optimized Association Rules for Numeric Attributes* (2008)
Takeshi Fukuda, Yasuhiko Morimoto, Takeshi Tokuyama
Given a huge database, we address the problem of finding association rules for numeric attributes, such as (Balance # I) O (CardLoan = yes), which implies that bank customers whose balances fall in a...
The Structure and Number of Global Roundings of a Graph (2008)
Tetsuo Asano, Naoki Katoh, Hisao Tamaki, Takeshi Tokuyama
Given a connected weighted graph G =(V,E), we consider a hypergraph HG = (V,PG) corresponding to the set of all shortest paths in G. For a given real assignment a on V satisfying 0 ≤ a(v) ≤ 1, a...
Improved Fixed-Parameter Algorithms for Non-Crossing Subgraphs 1 iETA #1 (2008)
Magnús M. Halldórsson, Takeshi Tokuyama, Alexander Wolff
We consider the problem of computing non-crossing spanning trees in topological graphs. It is known that it is NP-hard to decide whether a topological graph has a noncrossing spanning tree, and that...
Quantum computation in computational geometry (2008)
Kunihiko Sadakane, Norito Sugawara, Takeshi Tokuyama
We discuss applications of quantum computation to geometric data processing such as convex hulls, minimum enclosing balls, linear programming, and intersection problems. Technically, we apply...
Voronoi diagrams with respect to criteria on vision information (2008)
Asano, Tetsuo, Katoh, Naoki, Tamaki, Hisao, Tokuyama, Takeshi
Katsuki Fujisawa, Yukinobu Hamuro, Naoki Katoh, Takeshi Tokuyama, Katsutoshi Yada
. We consider the problem of finding two-dimensional association rules for categorical attributes. Suppose we have two conditional attributes A and B both of whose domains are categorical, and one...
Polyline Fitting of Planar Points under Min-sum Criteria (2006)
Aronov, Boris, Asano, Tetsuo, Katoh, Naoki, Mehlhorn, Kurt, Tokuyama, Takeshi
Fitting a curve of a certain type to a given set of points in the plane is a basic problem in statistics and has numerous applications. We consider fitting a polyline with k joints under the min-sum...
Polyline fitting of planar points under min-sum criteria (2006)
ARONOV, BORIS, ASANO, TETSUO, KATOH, NAOKI, MEHLHORN, KURT, TOKUYAMA, TAKESHI
Fitting a curve of a certain type to a given set of points in the plane is a basic problem in statistics and has numerous applications. We consider fitting a polyline with k joints under the min-sum...
Efficient Algorithms for Constructing a Pyramid from a Terrain (2006)
CHUN, Jinhee, SADAKANE, Kunihiko, TOKUYAMA, Takeshi
In [5], the following pyramid construction problem was proposed: Given nonnegative valued functions ρ and μ in d variables, we consider the optimal pyramid maximizing the total parametric gain of...
Peak-Reducing Fitting of a Curve under the Lp Metric (2005)
Jinhee Chun, Kunihiko Sadakane, Takeshi Tokuyama, Masato Yuki
Given a function y f ðxÞ in one variable, we consider the problem of computing a k-peaked curve y ðxÞ minimizing the Lp distance between them. In other words, ðxÞ has at most k local peaks and...
Polyline Fitting of Planar Points Under Min-sum Criteria (2004)
Aranov,Boris, Asano,Tetsuo, Katoh,Naoki, Mehlhorn,Kurt, Tokuyama,Takeshi
Polyline Fitting of Planar Points Under Min-sum Criteria (2004)
Aranov, Boris, Asano, Tetsuo, Katoh, Naoki, Mehlhorn, Kurt, Tokuyama, Takeshi, Fleischer, Rudolf, ...
On Properties of a Set of Global Roundings Associated with Clique Connection of Graphs (2004)
Tomonori Ishikawa, Ken-ich Kawarabayashi, Takeshi Tokuyama
Given a connected weighted graph G ðV; EÞ, we consider a hypergraph HðGÞ ðV; F ðGÞÞ corresponding to the set of all shortest paths in G. For a given real assignment a on V satisfying 0 aðvÞ...
Polyline Fitting of Planar Points Under Min-sum Criteria (2004)
Aranov, Boris, Asano, Tetsuo, Katoh, Naoki, Mehlhorn, Kurt, Tokuyama, Takeshi, Fleischer, Rudolf, ...
Notes on computing peaks in k-levels and parametric spanning trees (2001)
Katoh, Naoki, Tokuyama, Takeshi
We give an algorithm to compute all the local peaks in the $k$-level of an arrangement of $n$ lines in $O(n \log n) + \tilde{O}((kn)^{2/3})$ time. We can also find $\tau$ largest peaks in $O(n \log...
Labeling Points with Rectangles of Various Shapes (2001)
Nakano, Shin-ichi, Nishizeki, Takao, Tokuyama, Takeshi, Watanabe, Shuhei
We deal with a map-labeling problem, named LOFL (Left-part Ordered Flexible Labeling), to label a set of points in a plane with polygonal obstacles. The label for each point is selected from a set of...
Labeling Points with Rectangles of Various Shapes (2001)
Nakano, Shin-ichi, Nishizeki, Takao, Tokuyama, Takeshi, Watanabe, Shuhei
We deal with a map-labeling problem, named LOFL (Left-part Ordered Flexible Labeling), to label a set of points in a plane with polygonal obstacles. The label for each point is selected from a set of...
Asano, Tetsuo, Fujikawa, Naoki, Katoh, Naoki, Matsui, Tomomi, Nagamochi, Hiroshi, Tokuyama, Takeshi, ...
Labeling Points with Rectangles of Various Shapes (2001)
Nakano, Shin-ichi, Nishizeki, Takao, Tokuyama, Takeshi, Watanabe, Shuhei
We deal with a map-labeling problem, named LOFL (Left-part Ordered Flexible Labeling), to label a set of points in a plane with polygonal obstacles. The label for each point is selected from a set of...
www.elsevier.com/locate/comgeo Efficient algorithms for the minimum diameter bridge problem (2001)
Takeshi Tokuyama, Communicated J. Akiyama, T. Asano, M. Kano
We give efficient algorithms for constructing a bridge between two convex regions in a fixed dimensional space so that the diameter of the bridged region is minimized. If both the set of vertices and...
Notes on computing peaks in k-levels and parametric spanning trees (2001)
Katoh, Naoki, Tokuyama, Takeshi
Proceedings of the Seventeenth Annual Symposium on Computational Geometry, (SCG '01), June 3-5, 2001, Medford, Massachusetts, USA / sponsored by the ACM Special Interest Group for Graphics and...
Katsuki Fujisawa, Yukinobu Hamuro, Naoki Katoh, Takeshi Tokuyama, Katsutoshi Yada
Abstract. We consider the problem of finding two-dimensional association rules for categorical attributes. Suppose we have two conditional attributes A and B both of whose domains are categorical,...
Finding Subsets Maximizing Minimum Structures (1999)
Halldórsson, Magnús M., Iwano, Kazuo, Katoh, Naoki, Tokuyama, Takeshi
We consider the problem of finding a set of k vertices in a graph that are in some sense remote. Stated more formally, given a graph G and an integer k, find a set P of k vertices for which the total...
Lovasz's lemma for the three-dimensional k-level of concave surfaces and its applications (1999)
1 Introduction Investigation of the combinatorial properties of k-levels of arrangements of curves and surfaces is a central topic in combinatorial geometry. The k-level problem can be considered as...
Yasuhiko Morimoto, Takeshi Fukuda, Hirofumi Matsuzawa, Takeshi Tokuyama, Kunikazu Yoda
We consider the problem of finding association rules that make nearly optimal binary segmen-tations of huge categorical databases. The op-timality of segmentation is defined by an ob-jective function...
Polyline fitting of planar points under min-sum criteria (1998)
Boris Aronov, Tetsuo Asano, Naoki Katoh, Kurt Mehlhorn, Takeshi Tokuyama
Fitting a curve of a certain type to a given set of points in the plane is a basic problem in statistics and has numerous applications. We consider fitting a polyline with k joints under the min-sum...
Polyline Fitting of Planar Points under Min-Sum Criteria (1998)
Boris Aronov Tetsuo, Tetsuo Asano, Naoki Katoh, Kurt Mehlhorn, Takeshi Tokuyama
Fitting acurv e of a certain type to agiv en set of points in the plane is a basic problem in statistics and has numerous applications. We consider fitting a polyline with k joints under the min-sum...
Constructing Efficient Decision Trees by Using Optimized Numeric Association Rules (1996)
Takeshi Fukuda, Yasuhiko Morimoto, Shinichi Morishita, Takeshi Tokuyama
We propose an extension of an entropy-based heuristic of Quinlan [Q93] for constructing a decision tree from a large database with many numeric attributes. Quinlan pointed out that his original...
Mining optimized association rules for numeric attributes (1996)
Takeshi Fukuda, Yasuhiko Morimoto, Shinichi Morishita, Takeshi Tokuyama
Given a huge database, we address the problem of finding association rules for numeric attributes, such as (Balance c 1) + (CardLoan = yes), which implies that bank customers whose balances fall in a...
Constructing efficient decision trees by using optimized numeric association rules (1996)
Takeshi Fukuda, Yasuhiko Morimoto, Takeshi Tokuyama, Shinichi Morishita
We propose an extension of an entropy-based heuristic of Quinlan [Q93] for constructing a decision tree from a large database with many numeric attributes. Quinlan pointed out that his original...
Finding Subsets Maximizing Minimum Structures (1995)
Magnús M. Halldórsson, Kazuo Iwano, Naoki Katoh, Takeshi Tokuyama
We consider the problem of finding a set of k vertices in a graph that are in some sense remote, stated more formally: "Given a graph G and an integer k, and a set P of k vertices for which the...
On Zones of Flats in Hyperplane Arrangements (1992)
Michael E. Houle, Takeshi Tokuyama
Let H be a set of n hyperplanes in R d , let A(H) be its arrangement, and let b be an m-dimensional flat. The zone of b in the arrangement A(H) is the set of open d-dimensional cells of A(H) which...
TOKUYAMA, Takeshi, 徳山, 豪(1957-), トクヤマ, タケシ, Tokuyama, Takeshi
東北大学大学院情報科学研究科システム情報科学専攻,情報システム評価学講座 徳山豪教授のページ
TOKUYAMA, Takeshi, 徳山, 豪(1957-), トクヤマ, タケシ, Tokuyama, Takeshi
東北大学大学院情報科学研究科システム情報科学専攻,情報システム評価学講座 徳山豪教授のページ