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On Directed Steiner Trees
 In 13th Annual ACMSIAM Symposium on Discrete Algorithms
, 2002
"... The directed Steiner tree problem is the following: given a directed graph G = (V; E) with weights on the edges, a set of terminals S ` V , and a root vertex r, find a minimum weight outbranching T rooted at r, such that all vertices in S are included in T . This problem is known to be NPhard. Rece ..."
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The directed Steiner tree problem is the following: given a directed graph G = (V; E) with weights on the edges, a set of terminals S ` V , and a root vertex r, find a minimum weight outbranching T rooted at r, such that all vertices in S are included in T . This problem is known to be NPhard
Preferred Direction Steiner Trees
"... Interconnect optimization for VLSI circuits has received wide attention. To model routing surfaces, multiple circuit layers are frequently abstracted as a single rectilinear plane, ignoring via costs, layer dependent routing costs, and congestion impact for routing in a particular direction. In this ..."
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Cited by 8 (0 self)
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. In this paper, we consider preferred direction multilayer routing, which more closely models practical applications. We adapt a well known rectilinear planar Steiner tree heuristic, resulting in a new method to construct low cost Steiner trees under a realistic model. Our implementation is fast and effective
Linear Programming Hierarchies Suffice for Directed Steiner Tree
"... Abstract. We demonstrate that ` rounds of the SheraliAdams hierarchy and 2 ` rounds of the LovászSchrijver hierarchy suffice to reduce the integrality gap of a natural LP relaxation for Directed Steiner Tree in `layered graphs from Ω( k) to O( ` · log k) where k is the number of terminals. Th ..."
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Abstract. We demonstrate that ` rounds of the SheraliAdams hierarchy and 2 ` rounds of the LovászSchrijver hierarchy suffice to reduce the integrality gap of a natural LP relaxation for Directed Steiner Tree in `layered graphs from Ω( k) to O( ` · log k) where k is the number of ter
Parameterized complexity of directed steiner tree on sparse graphs
, 2012
"... We study the parameterized complexity of the directed variant of the classical Steiner Tree problem on various classes of directed sparse graphs. While the parameterized complexity of Steiner Tree parameterized by the number of terminals is well understood, not much is known about the parameteriza ..."
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Cited by 3 (1 self)
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We study the parameterized complexity of the directed variant of the classical Steiner Tree problem on various classes of directed sparse graphs. While the parameterized complexity of Steiner Tree parameterized by the number of terminals is well understood, not much is known about
Integrality ratio for group steiner trees and directed steiner trees
 In 14th Annual ACMSIAM Symposium on Discrete Algorithms
, 2003
"... The natural relaxation for the Group Steiner Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a flowbased linear programming relaxation. We prove new lower bounds on the integrality ratio of this relaxation. For the Group Steiner Tree problem, we show the integ ..."
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Cited by 29 (6 self)
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The natural relaxation for the Group Steiner Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a flowbased linear programming relaxation. We prove new lower bounds on the integrality ratio of this relaxation. For the Group Steiner Tree problem, we show
A series of approximation algorithms for the Acyclic Directed Steiner Tree problem
 ALGORITHMICA
, 1997
"... Given an acyclic directed network, a subset S of nodes (terminals), and a root r, the acyclic directed Steiner tree problem requires a minimumcost subnetwork which contains paths from r to each terminal. It is known that unless NP ` DT IME[n polylog n] no polynomialtime algorithm can guarantee be ..."
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Cited by 42 (1 self)
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Given an acyclic directed network, a subset S of nodes (terminals), and a root r, the acyclic directed Steiner tree problem requires a minimumcost subnetwork which contains paths from r to each terminal. It is known that unless NP ` DT IME[n polylog n] no polynomialtime algorithm can guarantee
FasterDSP: A Faster Approximation Algorithm for Directed Steiner Tree Problem
, 2006
"... Given a weighted directed graph G = (V, E, c), where c: E → R + is an edge cost function, a subset X of vertices (terminals), and a root vertex vr, the directed Steiner tree problem (DSP) asks for a minimumcost tree which spans the paths from root vertex vr to each terminal. Charikar et al.’s algor ..."
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Cited by 4 (0 self)
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Given a weighted directed graph G = (V, E, c), where c: E → R + is an edge cost function, a subset X of vertices (terminals), and a root vertex vr, the directed Steiner tree problem (DSP) asks for a minimumcost tree which spans the paths from root vertex vr to each terminal. Charikar et al.’s
A PolynomialTime SubpolynomApproximation Scheme for the Acyclic Directed Steiner Tree Problem
, 1994
"... The acyclic directed Steiner tree problem (ADSP) requires a minimal outward tree within an acyclic digraph with edge costs G = (V; E; d) which connects a root r with a distinguished subset S ae V , #S = k. The best possible performance guarantee of any polynomial approximation algorithm for ADSP can ..."
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The acyclic directed Steiner tree problem (ADSP) requires a minimal outward tree within an acyclic digraph with edge costs G = (V; E; d) which connects a root r with a distinguished subset S ae V , #S = k. The best possible performance guarantee of any polynomial approximation algorithm for ADSP
Induction of Decision Trees
 MACH. LEARN
, 1986
"... The technology for building knowledgebased systems by inductive inference from examples has been demonstrated successfully in several practical applications. This paper summarizes an approach to synthesizing decision trees that has been used in a variety of systems, and it describes one such syste ..."
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Cited by 4377 (4 self)
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The technology for building knowledgebased systems by inductive inference from examples has been demonstrated successfully in several practical applications. This paper summarizes an approach to synthesizing decision trees that has been used in a variety of systems, and it describes one
Results 1  10
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