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                Department of Mathematical Sciences
                   The Johns Hopkins University

                              SEMINAR

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Alan J. Goldman                                   November 01, 2001
Department of Mathematical Sciences               304 Whitehead Hall
The Johns Hopkins University                      Refreshments: 3:30 p.m.
                                                  Seminar: 4:00 p.m.

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        ISOLATION and EXCLUSION:  A  MATTER of COLOR 

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                               ABSTRACT


We discuss some novel graph coloring problems I posed a quarter-century 
ago.  Theoretical and algorithmic results  (due mainly to S. Maurer)
And binary-integer programming formulations (due to J.\ Whitin and the
speaker) will be described, as will generalizations and contributions due
to  A.\ Frank, E.\ Gyori and L.\ Lovasz.  We sketch both the original
sociological  motivations (concerning segregation and integration) and 
more speculative  recent ecological ones  concerning the optimal design 
of nature reserves. Some plausible extensions and applications will be
identified.