In this thesis, I survey 11 approximation algorithms.for unweighted set cover problem. I have also implemented the three algorithms.and created a software library that stores the code I have written. The algorithms.I ...
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In this thesis, I survey 11 approximation algorithms.for unweighted set cover problem. I have also implemented the three algorithms.and created a software library that stores the code I have written. The algorithms.I survey are: (1) Johnson’s standard greedy; (2) f-frequency greedy; (3) Goldsmidt, Hochbaum and Yu’s modified greedy; (4) Halldorsson’s local optimization; (5) Dur and Furer semi local optimization; (6) Asaf Levin’s improvement to Dur and Furer; (7) Simple rounding; (8) Randomized rounding; (9) LP duality; (10) Primal-dual schema; and (11) Network flow technique. Most of the algorithms.surveyed are refinements of standard greedy algorithm.
In this paper we study an optimization problem that arises in the design of communication networks. We show that this problem is NP-hard even when restricted to trees, and present several approximation results. In par...
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In this paper we study an optimization problem that arises in the design of communication networks. We show that this problem is NP-hard even when restricted to trees, and present several approximation results. In particular, we show that an integer programming formulation of the problem yields bounded ratio estimates for instances of the problem defined on trees. [ABSTRACT FROM AUTHOR]
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