An O((log log n)/sup 2/) time algorithm to compute the convex hull of sorted points on reconfigurable meshes

1998 ◽  
Vol 9 (12) ◽  
pp. 1167-1179 ◽  
Author(s):  
T. Hayashi ◽  
K. Nakano ◽  
S. Olarlu
2019 ◽  
Vol 13 (24) ◽  
pp. 1165-1180
Author(s):  
Jelloul Elmsbahi ◽  
Mohammed Khaldoun ◽  
Omar Bouattane ◽  
Ahmed Errami

1996 ◽  
Vol 06 (03) ◽  
pp. 345-353 ◽  
Author(s):  
KUO-LIANG CHUNG

A mesh-connected computer enhanced by a reconfigurable bus system is referred to as a reconfigurable mesh (RM). Given an n×n grey-scale image and m×m template, in this paper, an O( log m) time parallel algorithm for template matching is presented on a RM with O(m2n2) processors. Suppose the image and template are binary, an O(1) time algorithm is presented on a RM with O(m3n2) processors. Both algorithms are superior to the best known algorithms on RMs.


2012 ◽  
Vol 22 (05) ◽  
pp. 391-405
Author(s):  
DANNY Z. CHEN ◽  
HAITAO WANG

Given a set P of n points in the plane such that each point has a positive weight, we study the problem of finding an obnoxious line that intersects the convex hull of P and maximizes the minimum weighted Euclidean distance to all points of P. We present an O(n2 log n) time algorithm for the problem, improving the previously best-known O(n2 log 3 n) time solution. We also consider a variant of this problem whose input is a set of m polygons with a total of n vertices in the plane such that each polygon has a positive weight and whose goal is to locate an obnoxious line with respect to the weighted polygons. An O(mn + n log 2 n log m + m2 log n log 2 m) time algorithm for this variant was known previously. We give an improved algorithm of O(mn + n log 2 n + m2 log n) time. Further, we reduce the time bound of a previous algorithm for the case of the problem with unweighted polygons from O((m2 + n log m) log n) to O(m2 + n log m).


2011 ◽  
Vol 181-182 ◽  
pp. 661-666
Author(s):  
Xue Ming He ◽  
Yi Lu ◽  
Cheng Gang Li ◽  
Min Min Ni ◽  
Chen Liang Hua

Convex hull is a very important data structure of computational geometry design. This paper presents an algorithm to construct the convex hull of a set of scattered points by coordinates and relative angle method. The algorithm determines the convex vertexes and eliminates some non-convex vertexes, which greatly reduces the searching scope and the complexity. Delaunay triangulation is widely used in 3D surface reconstruction. Due to its duality, Delaunay triangulation is usually constructed through Voronoi diagram. Delaunay triangulation is directly constructed in this paper. The algorithm is simple, stable and easy to implement, especially for less data points.


1993 ◽  
Vol 11 (7) ◽  
pp. 447-455 ◽  
Author(s):  
Stephan Olariu ◽  
James L Schwing ◽  
Jingyuan Zhang

1991 ◽  
Vol 20 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Herbert Edelsbrunner ◽  
Weiping Shi

2010 ◽  
Vol 20 (01) ◽  
pp. 89-104 ◽  
Author(s):  
BORIS ARONOV ◽  
TETSUO ASANO ◽  
STEFAN FUNKE

Consider a set X of points in the plane and a set E of non-crossing segments with endpoints in X. One can efficiently compute the triangulation of the convex hull of the points, which uses X as the vertex set, respects E, and maximizes the minimum internal angle of a triangle. In this paper we consider a natural extension of this problem: Given in addition a Steiner pointp, determine the optimal location of p and a triangulation of X ∪ {p} respecting E, which is best among all triangulations and placements of p in terms of maximizing the minimum internal angle of a triangle. We present a polynomial-time algorithm for this problem and then extend our solution to handle any constant number of Steiner points.


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