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Related papers: Visibility-Monotonic Polygon Deflation

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Unfolding a convex polyhedron into a simple planar polygon is a well-studied problem. In this paper, we study the limits of unfoldability by studying nonconvex polyhedra with the same combinatorial structure as convex polyhedra. In…

Computational Geometry · Computer Science 2007-05-23 Marshall Bern , Erik D. Demaine , David Eppstein , Eric Kuo , Andrea Mantler , Jack Snoeyink

We prove that any compact surface with constant positive curvature and conical singularities can be decomposed into irreducible components of standard shape, glued along geodesic arcs connecting conical singularities. This is a spherical…

Geometric Topology · Mathematics 2022-01-05 Guillaume Tahar

We study the problem of decomposing (i.e. partitioning and covering) polygons into components that are $\alpha$-fat, which means that the aspect ratio of each subpolygon is at most $\alpha$. We consider decompositions without Steiner…

Computational Geometry · Computer Science 2021-03-17 Maike Buchin , Leonie Selbach

A convex polygon is defined as a sequence (V_0,...,V_{n-1}) of points on a plane such that the union of the edges [V_0,V_1],..., [V_{n-2},V_{n-1}], [V_{n-1},V_0] coincides with the boundary of the convex hull of the set of vertices…

General Mathematics · Mathematics 2007-05-23 Iosif Pinelis

Polygon spaces have been studied extensively, and yet missing from the literature is a simple property that every polygon has: dimension. This is distinct (possibly) from the dimension of the ambient space in which the polygon lives. A…

General Topology · Mathematics 2020-09-17 Jack Love

The visibility graph of a simple polygon represents visibility relations between its vertices. Knowing the correct order of the vertices around the boundary of a polygon and its visibility graph, it is an open problem to locate the vertices…

Computational Geometry · Computer Science 2019-05-03 Sahar Mehrpour , Alireza Zarei

In this work we introduce a mapping between the so called deformed hyperbolic potentials, which are presenting a continuous interest in the last few years, and the corresponding nondeformed ones. As a consequence, we conclude that these…

Quantum Physics · Physics 2009-11-11 A. de Souza Dutra

Let $P$ be a set of $n$ points in general position on the plane. A set of closed convex polygons with vertices in $P$, and with pairwise disjoint interiors is called a convex decomposition of $P$ if their union is the convex hull of $P$,…

Combinatorics · Mathematics 2019-09-16 Toshinori Sakai , Jorge Urrutia

We find a new regular solution of six-dimensional Einstein's equations with a positive cosmological constant. It has the same isometry group as the (deformed) conifold geometry, and the superpotential approach is used to solve the equations…

High Energy Physics - Theory · Physics 2015-09-02 Stanislav Kuperstein

There are many four vertex type theorems appearing in the literature, coming in both smooth and discrete flavors. The most familiar of these is the classical theorem in differential geometry, which states that the curvature function of a…

Metric Geometry · Mathematics 2023-02-09 Wiktor Mogilski , Kyle Grant

This paper presents a method for constructing flat deformations of associative algebras. We will refer to this method as method two because it is a generalisation of the method obtained in [1]. The deformations obtained using the first two…

Rings and Algebras · Mathematics 2025-07-08 Agata Smoktunowicz

We prove that, both in the hyperbolic and spherical 3-spaces, there exist nonconvex compact boundary-free polyhedral surfaces without selfintersections which admit nontrivial continuous deformations preserving all dihedral angles and study…

Metric Geometry · Mathematics 2014-09-10 Victor Alexandrov

We study the problem of invisibility for bodies with a mirror surface in the framework of geometrical optics. We show that for any two given directions it is possible to construct a two-dimensional fractal body invisible in these…

Dynamical Systems · Mathematics 2011-07-29 Alexander Plakhov , Vera Roshchina

There exists a surface of a convex polyhedron P and a partition L of P into geodesic convex polygons such that there are no connected "edge" unfoldings of P without self-intersections (whose spanning tree is a subset of the edge skeleton of…

Computational Geometry · Computer Science 2008-10-06 Alexey S Tarasov

We prove that octants are cover-decomposable, i.e., any 12-fold covering of any subset of the space with a finite number of translates of a given octant can be decomposed into two coverings. As a corollary, we obtain that any 12-fold…

Combinatorics · Mathematics 2015-03-17 Balázs Keszegh , Dömötör Pálvölgyi

For a polygon in Euclidean space we consider a transformation T which is obtained by applying the midpoints polygon construction twice and using an index shift. For a closed polygon this is a curve shortening process. A polygon is called…

Differential Geometry · Mathematics 2016-06-22 Christine Rademacher , Hans-Bert Rademacher

We prove that if a pure simplicial complex of dimension d with n facets has the least possible number of (d-1)-dimensional faces among all complexes with n faces of dimension d, then it is vertex decomposable. This answers a question of J.…

Combinatorics · Mathematics 2013-02-19 Michał Lasoń

Regular object detection methods output rectangle bounding boxes, which are unable to accurately describe the actual object shapes. Instance segmentation methods output pixel-level labels, which are computationally expensive for real-time…

Computer Vision and Pattern Recognition · Computer Science 2023-04-06 Yang Zheng , Oles Andrienko , Yonglei Zhao , Minwoo Park , Trung Pham

In this work, we present a general procedure, which is able to generate new exact solitonic models in 1+1 dimensions, from a known one, consisting of two coupled scalar fields. An interesting consequence of the method, is that of the…

High Energy Physics - Theory · Physics 2007-05-23 Alvaro de Souza Dutra

We prove that the following problem is co-RE-complete and thus undecidable: given three simple polygons, is there a tiling of the plane where every tile is an isometry of one of the three polygons (either allowing or forbidding…

Computational Geometry · Computer Science 2024-09-19 Erik D. Demaine , Stefan Langerman