. En-utilisant-la-première, OPT (I) Ainsi, on a une L-réduction avec ? 1 = 15, ? 2 = 1. On en déduit le seuil : A(I) ? (r ? ?)OPT (I) par hypothèse UGC A(I ) ? OPT (I ) + OPT (I) ? (r ? ?)OPT (I) A(I ) ? (r ? 1 ? ?)OPT (I, ) + OPT (I ) ? 2 ? ? 15 OPT (I ) + OPT (I )

N. Bansal and S. Khot, Inapproximability of Hypergraph Vertex Cover and Applications to Scheduling Problems, Automata, Languages and Programming, 37th International Colloquium, ICALP 2010 Proceedings, Part I, pp.250-261, 2010.
DOI : 10.1007/978-3-642-14165-2_22

I. Dinur, V. Guruswami, S. Khot, and O. Regev, A New Multilayered PCP and the Hardness of Hypergraph Vertex Cover, SIAM Journal on Computing, vol.34, issue.5, pp.1129-1146, 2005.
DOI : 10.1137/S0097539704443057

M. R. Garey and D. S. Johnson, Computers and Intractability : A Guide to the Theory of NP-Completeness, 1979.

C. H. Papadimitriou and M. Yannakakis, Optimization, approximation, and complexity classes, Journal of Computer and System Sciences, vol.43, issue.3, pp.425-440, 1991.
DOI : 10.1016/0022-0000(91)90023-X
URL : http://dx.doi.org/10.1016/0022-0000(91)90023-x

P. Poirion, S. Toubaline, C. D. Ambrosio, and L. Liberti, The power edge set problem, Networks, vol.61, issue.2, pp.104-120, 2016.
DOI : 10.1002/net.21684

S. Toubaline, C. D-'ambrosio, L. Liberti, P. Poirion, B. Schieber et al., Complexité du problème power edge set, 2016.

W. Yuill, A. Edwards, S. Chowdhury, and S. P. Chowdhury, Optimal PMU placement: A comprehensive literature review, 2011 IEEE Power and Energy Society General Meeting, pp.1-8, 2011.
DOI : 10.1109/PES.2011.6039376