http://www.mdpi.com/journal/algorithms/special_issues/computational_geometry/ "Computational geometry is a branch of computer science devoted to the study of algorithms which can be stated in terms of geometry. Some purely geometrical problems arise out of the study of computational geometric algorithms, and such problems are also considered to be part of computational geometry." (from http://en.wikipedia.org/wiki/Computational_geometry) Submission All papers should be submitted to algorithms@mdpi.org. To be published continuously until the deadline and papers will be listed together at the special issue website. Submitted papers should not have been published nor be under consideration for publication elsewhere. All papers are refereed through a peer-review process. A guide for authors is available on the Instructions for Authors page. Algorithms is an international peer-reviewed quarterly journal published by Molecular Diversity Preservation International. Article Processing Charges (APC) will be waived for well prepared manuscripts of invited papers. For the first three volumes of this new journal the APC are of 300 CHF (or 550 CHF per paper for those papers that require extensive additional formatting and/or English corrections) for papers submitted before 31 December 2010. http://www.mdpi.com/1999-4893/2/4/1327/ Recently a Delaunay refinement algorithm has been proposed that can mesh piecewise smooth complexes which include polyhedra, smooth and piecewise smooth surfaces, and non-manifolds. However, this algorithm employs domain dependent numerical predicates, some of which could be computationally expensive and hard to implement. In this paper we develop a refinement strategy that eliminates these complicated domain dependent predicates. As a result we obtain a meshing algorithm that is practical and implementation-friendly. http://www.mdpi.com/1999-4893/2/4/1327/ Wed, 11 Nov 2009 00:00:00 CET Algorithms 2009-11-11 2 4 Article 1327 1349 1999-4893 Delaunay Meshing of Piecewise Smooth Complexes without Expensive Predicates 2009-11-11 doi: 10.3390/a2041327 Tamal K. Dey Joshua A. Levine http://www.mdpi.com/1999-4893/2/3/1137/ Wireless sensor networks are a relatively new area where technology is developing fast and are used to solve a great diversity of problems that range from museums’ security to wildlife protection. The geometric optimisation problem solved in this paper is aimed at minimising the sensors’ range so that every point on a polygonal region R is within the range of at least two sensors. Moreover, it is also shown how to minimise the sensors’ range to assure the existence of a path within R that stays as close to two sensors as possible. http://www.mdpi.com/1999-4893/2/3/1137/ Mon, 14 Sep 2009 00:00:00 CEST Algorithms 2009-09-14 2 3 Article 1137 1154 1999-4893 Optimal 2-Coverage of a Polygonal Region in a Sensor Network 2009-09-14 doi: 10.3390/a2031137 Manuel Abellanas Antonio L. Bajuelos Inês Matos http://www.mdpi.com/1999-4893/2/3/1069/ We consider a pursuit-evasion problem where some lions have the task to clear a grid graph whose nodes are initially contaminated. The contamination spreads one step per time unit in each direction not blocked by a lion. A vertex is cleared from its contamination whenever a lion moves to it. Brass et al. [5] showed that n/2 lions are not enough to clear the n x n-grid. In this paper, we consider the same problem in dimension d > 2 and prove that Θ(nd-1/√d) lions are necessary and sufficient to clear the nd-grid. Furthermore, we analyze a problem variant where the lions are also allowed to jump from grid vertices to non-adjacent grid vertices. http://www.mdpi.com/1999-4893/2/3/1069/ Mon, 07 Sep 2009 00:00:00 CEST Algorithms 2009-09-07 2 3 Article 1069 1086 1999-4893 How Many Lions Are Needed to Clear a Grid? 2009-09-07 doi: 10.3390/a2031069 Florian Berger Alexander Gilbers Ansgar Grüne Rolf Klein