发布求助
文献互助 智能选刊 最新文献

International Journal of Computational Geometry and Applications最新文献

筛选
英文 中文
Area-Efficient Order-Preserving Planar Straight-Line Drawings of Ordered Trees 有序树的面积高效保序平面直线绘制
International Journal of Computational Geometry and Applications Pub Date : 2003-07-25 DOI: 10.1142/S021819590300130X
Ashim Garg, A. Rusu
{"title":"Area-Efficient Order-Preserving Planar Straight-Line Drawings of Ordered Trees","authors":"Ashim Garg, A. Rusu","doi":"10.1142/S021819590300130X","DOIUrl":"https://doi.org/10.1142/S021819590300130X","url":null,"abstract":"Ordered trees are generally drawn using order-preserving planar straight-line grid drawings. We therefore investigate the area-requirements of such drawings, and present several results: Let T be an ordered tree with n nodes. Then: - T admits an order-preserving planar straight-line grid drawing with O(n log n) area. - If T is a binary tree, then T admits an order-preserving planar straight-line grid drawing with O(n log log n) area. - If T is a binary tree, then T admits an order-preserving upward planar straight-line grid drawing with optimal O(n log n) area. \u0000 \u0000We also study the problem of drawing binary trees with user-specified arbitrary aspect ratios. We show that an ordered binary tree T with n nodes admits an order-preserving planar straight-line grid drawing Γ with width O(A + log n), height O((n/A) log A), and area O((A + log n)(n/A) log A) = O(n log n), where 2 ≤ A ≤ n is any user-specified number. Also note that all the drawings mentioned above can be constructed in O(n) time.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120916458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 29
Red-blue separability problems in 3D 三维中的红蓝可分性问题
International Journal of Computational Geometry and Applications Pub Date : 2003-05-18 DOI: 10.1142/S0218195905001646
F. Hurtado, C. Seara, S. Sethia
{"title":"Red-blue separability problems in 3D","authors":"F. Hurtado, C. Seara, S. Sethia","doi":"10.1142/S0218195905001646","DOIUrl":"https://doi.org/10.1142/S0218195905001646","url":null,"abstract":"In this paper we study the problems of separability of two disjoint point sets in 3D by multiple criteria extending some notions on separability of two disjoint point sets in the plane.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129294462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
Maximizing a Voronoi Region: the Convex Case Voronoi区域的最大化:凸情况
International Journal of Computational Geometry and Applications Pub Date : 2002-11-21 DOI: 10.1142/S0218195905001786
F. Dehne, R. Klein, R. Seidel
{"title":"Maximizing a Voronoi Region: the Convex Case","authors":"F. Dehne, R. Klein, R. Seidel","doi":"10.1142/S0218195905001786","DOIUrl":"https://doi.org/10.1142/S0218195905001786","url":null,"abstract":"Given a set S of s points in the plane, where do we place a new point, p, in order to maximize the area of its region in the Voronoi diagram of S and p? We study the case where the Voronoi neighbors of p are in convex position, and prove that there is at most one local maximum.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123766015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 34
Tetris is hard, even to approximate 俄罗斯方块很难，甚至很难近似
International Journal of Computational Geometry and Applications Pub Date : 2002-10-21 DOI: 10.1142/S0218195904001354
Ron Breukelaar, E. Demaine, S. Hohenberger, H. J. Hoogeboom, W. Kosters, D. Liben-Nowell
{"title":"Tetris is hard, even to approximate","authors":"Ron Breukelaar, E. Demaine, S. Hohenberger, H. J. Hoogeboom, W. Kosters, D. Liben-Nowell","doi":"10.1142/S0218195904001354","DOIUrl":"https://doi.org/10.1142/S0218195904001354","url":null,"abstract":"In the popular computer game of Tetris, the player is given a sequence of tetromino pieces and must pack them into a rectangular gameboard initially occupied by a given configuration of filled squares; any completely filled row of the gameboard is cleared and all pieces above it drop by one row. We prove that in the offline version of Tetris, it is NP-complete to maximize the number of cleared rows, maximize the number of tetrises (quadruples of rows simultaneously filled and cleared), minimize the maximum height of an occupied square, or maximize the number of pieces placed before the game ends. We furthermore show the extreme inapproximability of the first and last of these objectives to within a factor of p1-Ɛ, when given a sequence of p pieces, and the inapproximability of the third objective to within a factor of 2-Ɛ, for any Ɛ > 0. Our results hold under several variations on the rules of Tetris, including different models of rotation, limitations on player agility, and restricted piecesets.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134479912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 203
Approximating 3D Points With Cylindrical Segments 用圆柱段逼近三维点
International Journal of Computational Geometry and Applications Pub Date : 2002-08-15 DOI: 10.1142/S0218195904001421
B. Zhu
{"title":"Approximating 3D Points With Cylindrical Segments","authors":"B. Zhu","doi":"10.1142/S0218195904001421","DOIUrl":"https://doi.org/10.1142/S0218195904001421","url":null,"abstract":"In this paper, we study a 3D geometric problem originated from computing neural maps in the computational biology community: Given a set S of n points in 3D, compute k cylindrical segments (with different radii, orientations, lengths and no segment penetrates another) enclosing S such that the sum of their radii is minimized. There is no known result in this direction except when k = 1. The general problem is strongly NP-hard and we obtain a polynomial time approximation scheme (PTAS) for any fixed k > 1 in O(n3k-2/?4k-3) time by returning k cylindrical segments with sum of radii at most (1 + ?) of the corresponding optimal value. Our PTAS is built upon a simple (though slower) approximation algorithm for the case when k = 1.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115952122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 8
Collision Detection Optimization in a Multi-Particle System 多粒子系统中的碰撞检测优化
International Journal of Computational Geometry and Applications Pub Date : 2002-04-21 DOI: 10.1142/S0218195903001189
M. Gavrilova, J. Rokne
{"title":"Collision Detection Optimization in a Multi-Particle System","authors":"M. Gavrilova, J. Rokne","doi":"10.1142/S0218195903001189","DOIUrl":"https://doi.org/10.1142/S0218195903001189","url":null,"abstract":"Collision detection optimization algorithms in an event-driven simulation of a multi-particle system is one of crucial tasks, determining efficiency of simulation. We employ dynamic computational geometry data structures as a tool for collision detection optimization. The data structures under consideration are the dynamic generalized Voronoi diagram, the regular spatial subdivision, the regular spatial tree and the set of segment trees. Methods are studies in a framework of a granular-type materials system. Guidelines for selecting the most appropriate collision detection optimization technique summarize the paper.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130250081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 24
The Largest Empty Annulus Problem 最大空环问题
International Journal of Computational Geometry and Applications Pub Date : 2002-04-21 DOI: 10.1142/S0218195903001207
J. Díaz-Báñez, F. Hurtado, H. Meijer, D. Rappaport, J. A. Sellarès
{"title":"The Largest Empty Annulus Problem","authors":"J. Díaz-Báñez, F. Hurtado, H. Meijer, D. Rappaport, J. A. Sellarès","doi":"10.1142/S0218195903001207","DOIUrl":"https://doi.org/10.1142/S0218195903001207","url":null,"abstract":"Given a set of n points S in the Euclidean plane, we address the problem of computing an annulus A, (open region between two concentric circles) of largest width such that no point p ? S lies in the interior of A. This problem can be considered as a minimax facility location problem for n points such that the facility is a circumference. We give a characterization of the centres of annuli which are locally optimal and we show the the problem can be solved in O(n3 log n) time and O(n) space. We also consider the case in which the number of points in the inner circle is a fixed value k. When k ? O(n) our algorithm runs in O(n3 log n) time and O(n) space. However if k is small, that is a fixed constant, we can solve the problem in O(n log n) time and O(n) space.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133340953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 31
Computing the Diameter of a Point Set 计算一个点集的直径
International Journal of Computational Geometry and Applications Pub Date : 2002-04-03 DOI: 10.1142/S0218195902001006
G. Malandain, J. Boissonnat
{"title":"Computing the Diameter of a Point Set","authors":"G. Malandain, J. Boissonnat","doi":"10.1142/S0218195902001006","DOIUrl":"https://doi.org/10.1142/S0218195902001006","url":null,"abstract":"Given a finite set of points P in Rd, the diameter of P is defined as the maximum distance between two points of P. We propose a very simple algorithm to compute the diameter of a finite set of points. Although the algorithm is not worst-case optimal, it appears to be extremely fast for a large variety of point distributions.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131799951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 37
Labeling Points with Rectangles of Various Shapes 用各种形状的矩形标记点
International Journal of Computational Geometry and Applications Pub Date : 2000-09-20 DOI: 10.1142/S0218195902001018
A. Koike, Shin-Ichi Nakano, Takao Nishizeki, T. Tokuyama, Shuhei Watanabe
{"title":"Labeling Points with Rectangles of Various Shapes","authors":"A. Koike, Shin-Ichi Nakano, Takao Nishizeki, T. Tokuyama, Shuhei Watanabe","doi":"10.1142/S0218195902001018","DOIUrl":"https://doi.org/10.1142/S0218195902001018","url":null,"abstract":"We deal with a map-abeling problem, named LOFL (Left-part Ordered Flexible Labeling), to label a set of points in a plane in the presence of polygonal obstacles. The label for each point is selected from a set of rectangles with various shapes satisfying the left-part ordered property, and is placed near to the point after scaled by a scaling factor σ which is common to all points. In this paper, we give an optimal O((n + m) log (n + m)) algorithm to decide the feasibility of LOFL for a fixed scaling factor σ, and an O((n + m) log 2 (n + m)) time algorithm to find the largest feasible scaling factor σ, where n is the number of points and m is the total number of edges of the polygonal obstacles.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121963019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 13
Computing Constrained Shortest Segments: Butterfly Wingspans in Logarithmic Time 计算约束最短段:对数时间内的蝴蝶翼展
International Journal of Computational Geometry and Applications Pub Date : 1999-02-01 DOI: 10.1142/S0218195999000054
D. Kirkpatrick, J. Snoeyink
{"title":"Computing Constrained Shortest Segments: Butterfly Wingspans in Logarithmic Time","authors":"D. Kirkpatrick, J. Snoeyink","doi":"10.1142/S0218195999000054","DOIUrl":"https://doi.org/10.1142/S0218195999000054","url":null,"abstract":"We give a logarithmic-time algorithm to compute the shortest segment joining two convex n-gons A and B while avoiding another convex n-gon C. Our algorithm uses a tentative prune-and-search technique on standard representations of the polygons as arrays or balanced binary search trees.","PeriodicalId":285210,"journal":{"name":"International Journal of Computational Geometry and Applications","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117226773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信