By Richard A. Brualdi, Samad Hedayat, Hadi Kharaghani, Gholamreza B. Khosrovshahi, Shahriar Shahriari (ed.)

This quantity includes a number of papers provided on the overseas convention IPM 20--Combinatorics 2009, which was once held on the Institute for study in basic Sciences in Tehran, Iran, might 15-21, 2009. The convention celebrated IPM's twentieth anniversary and was once devoted to Reza Khosrovshahi, one of many founders of IPM and the director of its college of arithmetic from 1996 to 2007, at the social gathering of his seventieth birthday. The convention attracted a world team of exotic researchers from many various elements of combinatorics and graph concept, together with diversifications, designs, graph minors, graph coloring, graph eigenvalues, distance common graphs and organization schemes, hypergraphs, and arrangements.|This quantity incorporates a selection of papers awarded on the foreign convention IPM 20--Combinatorics 2009, which was once held on the Institute for study in basic Sciences in Tehran, Iran, may well 15-21, 2009. The convention celebrated IPM's twentieth anniversary and used to be devoted to Reza Khosrovshahi, one of many founders of IPM and the director of its university of arithmetic from 1996 to 2007, at the get together of his seventieth birthday. The convention attracted a global staff of amazing researchers from many alternative elements of combinatorics and graph idea, together with variations, designs, graph minors, graph coloring, graph eigenvalues, distance general graphs and organization schemes, hypergraphs, and preparations