Friendly Bin Packing Instances without Integer Round-up Property

Alberto Caprara, Mauro Dell'Amico, José Carlos Díaz Díaz, Manuel Iori and Romeo Rizzi

Abstract

It is well known that the gap between the optimal values of bin packing and fractional bin packing,
        if the latter is rounded up to the closest integer, is almost always null. Known counterexamples
        to this for integer input values involve fairly large numbers. Specifically, the first one was
        derived in 1986 and involved a bin capacity of the order of a billion. Later in 1998 a counterexample
        with a bin capacity of the order of a million was found. In this paper we show a large number of
        counterexamples with bin capacity of the order of a hundred, showing that the gap may be positive
        even for numbers which arise in customary applications. The associated instances are constructed
        starting from the Petersen graph and using the fact that it is fractionally, but not integrally,
        3-edge colorable.

Bibtex

@ARTICLE{CDDIR14,
        AUTHOR     = "Caprara, A. and Dell'Amico, M. and D\'iaz D\'iaz, J.C.
                      and Iori, M. and Rizzi, R.",
        TITLE      = "Friendly Bin Packing Instances without Integer Round-up Property",
        JOURNAL    = "Mathematical Programming Series A and B",
        YEAR       = 2014,
        DOI        = "10.1007/s10107-014-0791-z"
}