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Related papers: Robustly Guarding Polygons

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We study the problem of guarding the boundary of a simple polygon with a minimum number of guards such that each guard covers a contiguous portion of the boundary. First, we present a simple greedy algorithm for this problem that returns a…

Computational Geometry · Computer Science 2025-05-09 Ahmad Biniaz , Anil Maheshwari , Joseph S. B. Mitchell , Saeed Odak , Valentin Polishchuk , Thomas Shermer

There exist many variants of guarding an orthogonal polygon in an orthogonal fashion: sometimes a guard can see an entire rectangle, or along a staircase, or along an orthogonal path with at most $k$ bends. In this paper, we study all these…

Computational Geometry · Computer Science 2017-06-08 Therese Biedl , Saeed Mehrabi

We consider a variant of the art gallery problem where all guards are limited to seeing to the right inside a monotone polygon. We call such guards: half-guards. We provide a polynomial-time approximation for point guarding the entire…

Computational Geometry · Computer Science 2022-04-29 Hannah Miller Hillberg , Erik Krohn , Alex Pahlow

We present a 4-approximation algorithm for the problem of placing a fewest guards on a 1.5D terrain so that every point of the terrain is seen by at least one guard. This improves on the currently best approximation factor of 5. Our method…

Computational Geometry · Computer Science 2008-09-02 K. Elbassioni , D. Matijevic , J. Mestre , D. Severdija

The problem of vertex guarding a simple polygon was first studied by Subir K. Ghosh (1987), who presented a polynomial-time $O(\log n)$-approximation algorithm for placing as few guards as possible at vertices of a simple $n$-gon $P$, such…

Computational Geometry · Computer Science 2019-07-03 Stav Ashur , Omrit Filtser , Matthew J. Katz

We provide a spectrum of results for the Universal Guard Problem, in which one is to obtain a small set of points ("guards") that are "universal" in their ability to guard any of a set of possible polygonal domains in the plane. We give…

Computational Geometry · Computer Science 2017-03-28 Sándor P. Fekete , Qian Li , Joseph S. B. Mitchell , Christian Scheffer

We investigate the problem of optimally assigning a large number of robots (or other types of autonomous agents) to guard the perimeters of closed 2D regions, where the perimeter of each region to be guarded may contain multiple disjoint…

Robotics · Computer Science 2019-05-14 Si Wei Feng , Shuai D. Han , Kai Gao , Jingjin Yu

The art gallery problem enquires about the least number of guards sufficient to ensure that an art gallery, represented by a simple polygon $P$, is fully guarded. Most standard versions of this problem are known to be NP-hard. In 1987,…

Computational Geometry · Computer Science 2018-04-12 Pritam Bhattacharya , Subir Kumar Ghosh , Sudebkumar Pal

The art gallery problem enquires about the least number of guards that are sufficient to ensure that an art gallery, represented by a polygon $P$, is fully guarded. In 1998, the problems of finding the minimum number of point guards, vertex…

Computational Geometry · Computer Science 2016-05-03 Pritam Bhattacharya , Subir Kumar Ghosh , Bodhayan Roy

Robust estimation is much more challenging in high dimensions than it is in one dimension: Most techniques either lead to intractable optimization problems or estimators that can tolerate only a tiny fraction of errors. Recent work in…

Machine Learning · Computer Science 2018-03-14 Ilias Diakonikolas , Gautam Kamath , Daniel M. Kane , Jerry Li , Ankur Moitra , Alistair Stewart

A sliding camera inside an orthogonal polygon $P$ is a point guard that travels back and forth along an orthogonal line segment $\gamma$ in $P$. The sliding camera $g$ can see a point $p$ in $P$ if the perpendicular from $p$ onto $\gamma$…

Computational Geometry · Computer Science 2016-04-26 Therese Biedl , Timothy M. Chan , Stephanie Lee , Saeed Mehrabi , Fabrizio Montecchiani , Hamideh Vosoughpour

Given a simple polygon $\cal P$, in the Art Gallery problem the goal is to find the minimum number of guards needed to cover the entire $\cal P$, where a guard is a point and can see another point $q$ when $\overline{pq}$ does not cross the…

Computational Geometry · Computer Science 2021-12-03 Arash Vaezi , Mohammad Ghodsi

We investigate the problem of using mobile robots equipped with 2D range sensors to optimally guard perimeters or regions, i.e., 1D or 2D sets. Given such a set of arbitrary shape to be guarded, and $k$ mobile sensors where the $i$-th…

Robotics · Computer Science 2020-06-11 Si Wei Feng , Jingjin Yu

In the continuous 1.5-dimensional terrain guarding problem we are given an $x$-monotone chain (the \emph{terrain} $T$) and ask for the minimum number of point guards (located anywhere on $T$), such that all points of $T$ are covered by at…

Computational Geometry · Computer Science 2014-07-29 Stephan Friedrichs , Michael Hemmer , Christiane Schmidt

Formal explainability guarantees the rigor of computed explanations, and so it is paramount in domains where rigor is critical, including those deemed high-risk. Unfortunately, since its inception formal explainability has been hampered by…

Artificial Intelligence · Computer Science 2024-12-04 Xuanxiang Huang , Joao Marques-Silva

Neural networks are becoming increasingly prevalent in software, and it is therefore important to be able to verify their behavior. Because verifying the correctness of neural networks is extremely challenging, it is common to focus on the…

Machine Learning · Computer Science 2019-02-19 Ravi Mangal , Aditya V. Nori , Alessandro Orso

Victor Klee introduce the art gallery problem during a conference in Stanford in August 1976 with that question: "How many guards are required to guard an art gallery?" In 1987, Ghosh provided an approximation algorithm for vertex guards…

Computational Geometry · Computer Science 2022-03-04 Shiva Maleki , Ali Mohades

Terrain Guarding Problem(TGP), which is known to be NP-complete, asks to find a smallest set of guard locations on a terrain $T$ such that every point on $T$ is visible by a guard. Here, we study this problem on 1.5D orthogonal terrains…

Computational Geometry · Computer Science 2016-05-19 Yangdi Lyu , Alper Üngör

Localized adversarial patches aim to induce misclassification in machine learning models by arbitrarily modifying pixels within a restricted region of an image. Such attacks can be realized in the physical world by attaching the adversarial…

Computer Vision and Pattern Recognition · Computer Science 2021-04-01 Chong Xiang , Arjun Nitin Bhagoji , Vikash Sehwag , Prateek Mittal

A set $G$ of points on a 1.5-dimensional terrain, also known as an $x$-monotone polygonal chain, is said to guard the terrain if any point on the terrain is 'seen' by a point in $G$. Two points on the terrain see each other if and only if…

Computational Geometry · Computer Science 2009-07-08 James King , Erik Krohn
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