منابع مشابه
Stabbing Planes
We introduce and develop a new semi-algebraic proof system, called Stabbing Planes that is in the style of DPLL-based modern SAT solvers. As with DPLL, there is only one rule: the current polytope can be subdivided by branching on an inequality and its “integer negation.” That is, we can (nondeterministically choose) a hyperplane ax ≥ b with integer coefficients, which partitions the polytope i...
متن کاملApproximation Algorithms for Rectangle Stabbing and Interval Stabbing Problems
In the weighted rectangle stabbing problem we are given a grid in ]R2 consisting of columns and rows each having a positive integral weight, and a set of closed axis-parallel rectangles each having a positive integral demand. The rectangles are placed arbitrarily in the grid with the only assumption that each rectangle is intersected by at least one column and at least one row. The objective is...
متن کاملZero-Parity Stabbing Information
Everett et al. [EHN96, EHN97] introduced several varieties of stabbing information for the lines determined by pairs of vertices of a simple polygon P , and established their relationships to vertex visibility and other combinatorial data. In the same spirit, we define the “zero-parity (ZP) stabbing information” to be a natural weakening of their “weak stabbing information,” retaining only the ...
متن کاملStabbing Delaunay Tetrahedralizations
A Delaunay tetrahedralization of n vertices is exhibited for which a straight line can pass through the interiors of Θ(n) tetrahedra. This solves an open problem of Nina Amenta, who asked whether a line can stab more than O(n) tetrahedra. The construction generalizes to higher dimensions: in d dimensions, a line can stab the interiors of Θ(ndd/2e) Delaunay d-simplices. The relationship between ...
متن کامل3 Stabbing segments
In this paper, we answer the question: Given a collection of compact sets, can one decide in polynomial time whether there exists a convex body whose boundary intersects every set in the collection? We prove that already when the sets are segments in the plane, deciding existence of a convex stabber is NP-complete. On the positive side, we give a polynomial-time algorithm (in the full paper) to...
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ژورنال
عنوان ژورنال: Journalism Practice
سال: 2015
ISSN: 1751-2786,1751-2794
DOI: 10.1080/17512786.2015.1058179