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Alan J. Hoffman
Researcher at IBM
Publications - 91
Citations - 6721
Alan J. Hoffman is an academic researcher from IBM. The author has contributed to research in topics: Matrix (mathematics) & Linear programming. The author has an hindex of 32, co-authored 91 publications receiving 6270 citations. Previous affiliations of Alan J. Hoffman include University of Wisconsin-Madison & General Electric.
Papers
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Journal ArticleDOI
On approximate solutions of systems of linear inequalities
TL;DR: In this paper, it is shown that if (1) is consistent, one can infer that there is a solution x0 of (1)-close to x. The purpose of this report is to justify and formulate precisely this assertion.
Journal ArticleDOI
Lower bounds for the partitioning of graphs
W. E. Donath,Alan J. Hoffman +1 more
TL;DR: In this paper, it was shown that the right-hand side is a concave function of the diagonal matrix U such that the sum of the adjacency matrix of the graph plus all the elements of the sum matrix is zero.
Journal ArticleDOI
A characterization of comparability graphs and of interval graphs
P. C. Gilmore,Alan J. Hoffman +1 more
TL;DR: In this paper, the authors give a simple algorithm for directing all the edges of a comparability graph in such a way that the resulting graph partially orders its vertices, which they call comparability graphs.
Journal ArticleDOI
On Moore graphs with diameters 2 and 3
Alan J. Hoffman,R. R. Singleton +1 more
TL;DR: The proof exploits the characteristic roots and vectors of the adjacency matrix (and its principal submatrices) of the graph to prove the existence of connected, undirected graphs homogeneous of degree d and of diameter k.
Book ChapterDOI
Integral Boundary Points of Convex Polyhedra
TL;DR: If the “right hand side” consists of integers, and if the matrix is “totally unimodular”, then the vertices of the polyhedron defined by the linear inequalities will all be integral.