All reports by Author Guy Kortsarz:

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TR07-120
| 5th October 2007
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Sharon Feldman, Guy Kortsarz, Zeev Nutov#### Improved approximation algorithms for directed Steiner forest

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TR06-008
| 23rd November 2005
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MohammadTaghi Hajiaghayi, Guy Kortsarz, Mohammad R. Salavatipour#### Polylogarithmic Approximation Algorithm for Non-Uniform Multicommodity Buy-at-Bulk

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TR06-007
| 23rd November 2005
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MohammadTaghi Hajiaghayi, Guy Kortsarz, Mohammad R. Salavatipour#### Approximating Buy-at-Bulk $k$-Steiner trees

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TR03-035
| 21st May 2003
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Eran Halperin, Guy Kortsarz, Robert Krauthgamer#### Tight lower bounds for the asymmetric k-center problem

Sharon Feldman, Guy Kortsarz, Zeev Nutov

We consider the k-Directed Steiner Forest} (k-dsf) problem:

given a directed graph G=(V,E) with edge costs, a collection D subseteq V \times V

of ordered node pairs, and an integer k leq |D|, find a minimum cost subgraph

H of G

that contains an st-path for (at least) k ...
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MohammadTaghi Hajiaghayi, Guy Kortsarz, Mohammad R. Salavatipour

We consider the non-uniform multicommodity buy-at-bulk network

design problem. In this problem we are given a graph $G(V,E)$ with

two cost functions on the edges, a buy cost $b:E\longrightarrow \RR^+$ and a rent cost

$r:E\longrightarrow\RR^+$, and a set of source-sink pairs $s_i,t_i\in V$ ($1\leq i\leq \alpha$)

with each pair $i$ ...
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MohammadTaghi Hajiaghayi, Guy Kortsarz, Mohammad R. Salavatipour

In the buy-at-bulk $k$-Steiner tree (or rent-or-buy

$k$-Steiner tree) problem we are given a graph $G(V,E)$ with a set

of terminals $T\subseteq V$ including a particular vertex $s$ called

the root, and an integer $k\leq |T|$. There are two cost functions

on the edges of $G$, a buy cost $b:E\longrightarrow ...
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Eran Halperin, Guy Kortsarz, Robert Krauthgamer

In the {\sc $k$-center} problem, the input is a bound $k$

and $n$ points with the distance between every two of them,

such that the distances obey the triangle inequality.

The goal is to choose a set of $k$ points to serve as centers,

so that the maximum distance ...
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