@inproceedings{e3e97c19a85148ed952d69f15d23dab8,

title = "On guarding rectilinear domains",

abstract = "We prove that guarding the vertices of a rectilinear polygon P, whether by guards lying at vertices of P, or by guards lying on the boundary of P, or by guards lying anywhere in P, is NP-hard. For the first two proofs (i.e., vertex guards and boundary guards), we construct a reduction from minimum piercing of 2-intervals. The third proof is somewhat simpler; it is obtained by adapting a known reduction from minimum line cover. We also consider the problem of guarding the vertices of a 1.5D rectilinear terrain by vertex guards. We establish an interesting connection between this problem and the problem of computing a minimum clique cover in chordal graphs. This connection yields a 2-approximation algorithm for the guarding problem.",

author = "Katz, {Matthew J.} and Roisman, {Gabriel S.}",

year = "2006",

month = jan,

day = "1",

doi = "10.1007/11785293_22",

language = "English",

isbn = "354035753X",

series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",

publisher = "Springer Verlag",

pages = "220--231",

booktitle = "Biomedical Simulation - Third International Symposium, ISBMS 2006, Proceedings",

address = "Germany",

note = "10th Scandinavian Workshop on Algorithm Theory, SWAT 2006 ; Conference date: 06-07-2006 Through 08-07-2006",

}