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Motivated by the settings where sensing the entire tensor is infeasible, this paper proposes a novel tensor compressed sensing model, where measurements are only obtained from sensing each lateral slice via mutually independent matrices.…

Machine Learning · Computer Science 2024-12-24 Tongle Wu , Ying Sun , Jicong Fan

Consider a set $P \subseteq \Re^d$ of $n$ points, and a convex body $C$ provided via a separation oracle. The task at hand is to decide for each point of $P$ if it is in $C$ using the fewest number of oracle queries. We show that one can…

Computational Geometry · Computer Science 2021-04-02 Sariel Har-Peled , Mitchell Jones , Saladi Rahul

This paper shows that the OSGA algorithm -- which uses first-order information to solve convex optimization problems with optimal complexity -- can be used to efficiently solve arbitrary bound-constrained convex optimization problems. This…

Optimization and Control · Mathematics 2015-01-08 Masoud Ahookhosh , Arnold Neumaier

We consider the width $X_T(\omega)$ of a convex $n$-gon $T$ in the plane along the random direction $\omega\in\mathbb{R}/2\pi \mathbb{Z}$ and study its deviation rate: $$…

Probability · Mathematics 2022-01-19 Shigeki Akiyama , Teturo Kamae

Image reconstruction in X ray tomography consists in determining an object from its projections. In many applications such as non destructive testing, we look for an image who has a constant value inside a region (default) and another…

Data Analysis, Statistics and Probability · Physics 2007-05-23 A. Mohammad-Djafari

This article proposes a new discrete framework for approximating solutions to shape optimization problems under convexity constraints. The numerical method, based on the support function or the gauge function, is guaranteed to generate…

Optimization and Control · Mathematics 2022-03-15 Beniamin Bogosel

We study several problems concerning convex polygons whose vertices lie in a Cartesian product of two sets of $n$ real numbers (for short, \emph{grid}). First, we prove that every such grid contains $\Omega(\log n)$ points in convex…

Computational Geometry · Computer Science 2021-10-05 Jean-Lou De Carufel , Adrian Dumitrescu , Wouter Meulemans , Tim Ophelders , Claire Pennarun , Csaba D Tóth , Sander Verdonschot

Given a convex region in the plane, and a sweep-line as a tool, what is best way to reduce the region to a single point by a sequence of sweeps? The problem of sweeping points by orthogonal sweeps was first studied in [2]. Here we consider…

Computational Geometry · Computer Science 2015-03-18 Adrian Dumitrescu , Minghui Jiang

We propose a simple algorithm to locate the "corner" of an L-curve, a function often used to select the regularisation parameter for the solution of ill-posed inverse problems. The algorithm involves the Menger curvature of a circumcircle…

Numerical Analysis · Mathematics 2020-09-25 Alessandro Cultrera , Luca Callegaro

We consider the following geometric optimization problem: find a convex polygon of maximum area contained in a given simple polygon $P$ with $n$ vertices. We give a randomized near-linear-time $(1-\varepsilon)$-approximation algorithm for…

Computational Geometry · Computer Science 2017-10-17 Sergio Cabello , Josef Cibulka , Jan Kynčl , Maria Saumell , Pavel Valtr

We show that a polygon can be uniquely determined by the lengths of non-central sections supporting a piecewise-analytic hedgehog in the interior of the polygon. We also prove the analogous result for slab areas - centrally-symmetric…

Metric Geometry · Mathematics 2026-03-03 Brendan Matthews

We introduce a notion of $k$-convexity and explore polygons in the plane that have this property. Polygons which are \mbox{$k$-convex} can be triangulated with fast yet simple algorithms. However, recognizing them in general is a 3SUM-hard…

Computational Geometry · Computer Science 2010-07-22 Oswin Aichholzer , Franz Aurenhammer , Erik D. Demaine , Ferran Hurtado , Pedro Ramos , Jorge Urrutia

A convex polygon Q is circumscribed about a convex polygon P if every vertex of P lies on at least one side of Q. We present an algorithm for finding a maximum area convex polygon circumscribed about any given convex n-gon in O(n^3) time.…

Metric Geometry · Mathematics 2024-03-25 Markus Ausserhofer , Susanna Dann , Zsolt Lángi , Géza Tóth

In this paper, we discuss the algorithm engineering aspects of an O(n^2)-time algorithm [6] for computing a minimum-area convex polygon that intersects a set of n isothetic line segments.

Computational Geometry · Computer Science 2016-09-07 Xin Wu , Xijie Zeng , Bryan St. Amour , Asish Mukhopadhyay

In this article we pose the problem of existence and uniqueness of convex body for which the projection curvature radius function coincides with given function. We find a necessary and sufficient condition that ensures a positive answer to…

Differential Geometry · Mathematics 2016-09-07 Aramyan Rafik

We explore optimal circular nonconvex partitions of regular k-gons. The circularity of a polygon is measured by its aspect ratio: the ratio of the radii of the smallest circumscribing circle to the largest inscribed disk. An optimal…

Computational Geometry · Computer Science 2007-05-23 Mirela Damian , Joseph O'Rourke

Compacting orthogonal drawings is a challenging task. Usually algorithms try to compute drawings with small area or edge length while preserving the underlying orthogonal shape. We present a one-dimensional compaction algorithm that alters…

Data Structures and Algorithms · Computer Science 2017-06-21 Michael Jünger , Petra Mutzel , Christiane Spisla

We consider the problem of monitoring an art gallery modeled as a polygon, the edges of which are arcs of curves, with edge or mobile guards. Our focus is on piecewise-convex polygons, i.e., polygons that are locally convex, except possibly…

Computational Geometry · Computer Science 2011-03-01 Menelaos I. Karavelas

We study the problem of reconstructing a convex body using only a finite number of measurements of outer normal vectors. More precisely, we suppose that the normal vectors are measured at independent random locations uniformly distributed…

Computational Geometry · Computer Science 2014-02-21 Hiba Abdallah , Quentin Mérigot

We study the problem of computing a shortest tour that visits a sequence of $k$ polygons $P_1,\dots, P_k$ with a total number of $n$ vertices. A tour is an oriented curve such that there exist points $p_i\in P_i$ for all $i$ where $p_i$…

Computational Geometry · Computer Science 2026-05-14 Katrin Casel , Sándor Kisfaludi-Bak , Linda Kleist , Jeroen S. K. Lamme , Eunjin Oh , Yanheng Wang