منابع مشابه
On Guarding Orthogonal Polygons with Bounded Treewidth
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 a orthogonal path with at most k bends. In this paper, we study all these guarding models in the special case of orthogonal polygons that have bounded treewidth in some sense. Exploiting algorithms for graphs of bounded treewidth, we...
متن کاملOn Guarding Orthogonal Polygons with Sliding Cameras
A sliding camera inside an orthogonal polygon P is a point guard that travels back and forth along an orthogonal line segment γ in P . The sliding camera g can see a point p in P if the perpendicular from p onto γ is inside P . In this paper, we give the first constant-factor approximation algorithm for the problem of guarding P with the minimum number of sliding cameras. Next, we show that the...
متن کاملGuarding Path Polygons with Orthogonal Visibility
We are interested in the problem of guarding simple orthogonal polygons with the minimum number of r-guards. The interior point p belongs an orthogonal polygon P is visible from r-guard g, if the minimum area rectangle contained p and q lies within P . A set of point guards in polygon P is named guard set (as denoted G) if the union of visibility areas of these point guards be equal to polygon ...
متن کاملOn r-Guarding Thin Orthogonal Polygons
Guarding a polygon with few guards is an old and well-studied problem in computational geometry. Here we consider the following variant: We assume that the polygon is orthogonal and thin in some sense, and we consider a point p to guard a point q if and only if the minimum axis-aligned rectangle spanned by p and q is inside the polygon. A simple proof shows that this problem is NP-hard on ortho...
متن کاملNew Hardness Results for Guarding Orthogonal Polygons with Sliding Cameras
Let P be an orthogonal polygon. Consider a sliding camera that travels back and forth along an orthogonal line segment s ∈ P as its trajectory. The camera can see a point p ∈ P if there exists a point q ∈ s such that pq is a line segment normal to s that is completely inside P . In the minimum-cardinality sliding cameras problem, the objective is to find a set S of sliding cameras of minimum ca...
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ژورنال
عنوان ژورنال: International Journal of Apllied Mathematics
سال: 2016
ISSN: 1311-1728,1314-8060
DOI: 10.12732/ijam.v29i1.8