IEICE TRANSACTIONS on Fundamentals
Characterizing Link-2 LR-Visibility Polygons and Related Problems
Summary :
Two points x, y inside a simple polygon P are said to be mutually link-2 visible if there exists the third point z ∈ P such that z is visible from both x and y. The polygon P is link-2 LR-visible if there are two points s, t on the boundary of P such that every point on the clockwise boundary of P from s to t is link-2 visible from some point of the other boundary of P from t to s and vice versa. We give a characterization of link-2 LR-visibility polygons by generalizing the known result on LR-visibility polygons. A new idea is to extend the concepts of ray-shootings and components to those under notion of link-2 visibility. Then, we develop an O(n log n) time algorithm to determine whether a given polygon is link-2 LR-visible. Using the characterization of link-2 LR-visibility polygons, we further present an O(n log n) time algorithm for determining whether a polygonal region is searchable by a k-searcher, k ≥ 2. This improves upon the previous O(n2) time bound [9]. A polygonal region P is said to be searchable by a searcher if the searcher can detect (or see) an unpredictable intruder inside the region, no matter how fast the intruder moves. A k-searcher holds k flashlights and can see only along the rays of the flashlights emanating from his position.
- Publication
- IEICE TRANSACTIONS on Fundamentals Vol.E102-A No.2 pp.423-429
- Publication Date
- 2019/02/01
- Publicized
- Online ISSN
- 1745-1337
- DOI
- 10.1587/transfun.E102.A.423
- Type of Manuscript
- PAPER
- Category
- Algorithms and Data Structures
Authors
Xuehou TAN
Tokai University
Bo JIANG
Dalian Maritime University
Keyword
Latest Issue
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Xuehou TAN, Bo JIANG, "Characterizing Link-2 LR-Visibility Polygons and Related Problems" in IEICE TRANSACTIONS on Fundamentals,
vol. E102-A, no. 2, pp. 423-429, February 2019, doi: 10.1587/transfun.E102.A.423.
Abstract: Two points x, y inside a simple polygon P are said to be mutually link-2 visible if there exists the third point z ∈ P such that z is visible from both x and y. The polygon P is link-2 LR-visible if there are two points s, t on the boundary of P such that every point on the clockwise boundary of P from s to t is link-2 visible from some point of the other boundary of P from t to s and vice versa. We give a characterization of link-2 LR-visibility polygons by generalizing the known result on LR-visibility polygons. A new idea is to extend the concepts of ray-shootings and components to those under notion of link-2 visibility. Then, we develop an O(n log n) time algorithm to determine whether a given polygon is link-2 LR-visible. Using the characterization of link-2 LR-visibility polygons, we further present an O(n log n) time algorithm for determining whether a polygonal region is searchable by a k-searcher, k ≥ 2. This improves upon the previous O(n2) time bound [9]. A polygonal region P is said to be searchable by a searcher if the searcher can detect (or see) an unpredictable intruder inside the region, no matter how fast the intruder moves. A k-searcher holds k flashlights and can see only along the rays of the flashlights emanating from his position.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/transfun.E102.A.423/_p
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@ARTICLE{e102-a_2_423,
author={Xuehou TAN, Bo JIANG, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={Characterizing Link-2 LR-Visibility Polygons and Related Problems},
year={2019},
volume={E102-A},
number={2},
pages={423-429},
abstract={Two points x, y inside a simple polygon P are said to be mutually link-2 visible if there exists the third point z ∈ P such that z is visible from both x and y. The polygon P is link-2 LR-visible if there are two points s, t on the boundary of P such that every point on the clockwise boundary of P from s to t is link-2 visible from some point of the other boundary of P from t to s and vice versa. We give a characterization of link-2 LR-visibility polygons by generalizing the known result on LR-visibility polygons. A new idea is to extend the concepts of ray-shootings and components to those under notion of link-2 visibility. Then, we develop an O(n log n) time algorithm to determine whether a given polygon is link-2 LR-visible. Using the characterization of link-2 LR-visibility polygons, we further present an O(n log n) time algorithm for determining whether a polygonal region is searchable by a k-searcher, k ≥ 2. This improves upon the previous O(n2) time bound [9]. A polygonal region P is said to be searchable by a searcher if the searcher can detect (or see) an unpredictable intruder inside the region, no matter how fast the intruder moves. A k-searcher holds k flashlights and can see only along the rays of the flashlights emanating from his position.},
keywords={},
doi={10.1587/transfun.E102.A.423},
ISSN={1745-1337},
month={February},}
Copy
TY - JOUR
TI - Characterizing Link-2 LR-Visibility Polygons and Related Problems
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 423
EP - 429
AU - Xuehou TAN
AU - Bo JIANG
PY - 2019
DO - 10.1587/transfun.E102.A.423
JO - IEICE TRANSACTIONS on Fundamentals
SN - 1745-1337
VL - E102-A
IS - 2
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - February 2019
AB - Two points x, y inside a simple polygon P are said to be mutually link-2 visible if there exists the third point z ∈ P such that z is visible from both x and y. The polygon P is link-2 LR-visible if there are two points s, t on the boundary of P such that every point on the clockwise boundary of P from s to t is link-2 visible from some point of the other boundary of P from t to s and vice versa. We give a characterization of link-2 LR-visibility polygons by generalizing the known result on LR-visibility polygons. A new idea is to extend the concepts of ray-shootings and components to those under notion of link-2 visibility. Then, we develop an O(n log n) time algorithm to determine whether a given polygon is link-2 LR-visible. Using the characterization of link-2 LR-visibility polygons, we further present an O(n log n) time algorithm for determining whether a polygonal region is searchable by a k-searcher, k ≥ 2. This improves upon the previous O(n2) time bound [9]. A polygonal region P is said to be searchable by a searcher if the searcher can detect (or see) an unpredictable intruder inside the region, no matter how fast the intruder moves. A k-searcher holds k flashlights and can see only along the rays of the flashlights emanating from his position.
ER -
English
