49,574 research outputs found

    On a conjecture about enumerating (2+2)(2+2)-free posets

    Get PDF
    Recently, Kitaev and Remmel posed a conjecture concerning the generating function for the number of unlabeled (2+2)(2+2)-free posets with respect to number of elements and number of minimal elements. In this paper, we present a combinatorial proof of this conjecture

    On a refinement of Wilf-equivalence for permutations

    Full text link
    Recently, Dokos et al. conjectured that for all k,m1k, m\geq 1, the patterns 12k(k+m+1)(k+2)(k+1) 12\ldots k(k+m+1)\ldots (k+2)(k+1) and (m+1)(m+2)(k+m+1)m21(m+1)(m+2)\ldots (k+m+1)m\ldots 21 are majmaj-Wilf-equivalent. In this paper, we confirm this conjecture for all k1k\geq 1 and m=1m=1. In fact, we construct a descent set preserving bijection between 12k(k1) 12\ldots k (k-1) -avoiding permutations and 23k123\ldots k1-avoiding permutations for all k3k\geq 3. As a corollary, our bijection enables us to settle a conjecture of Gowravaram and Jagadeesan concerning the Wilf-equivalence for permutations with given descent sets

    One Dimensional nnary Density Classification Using Two Cellular Automaton Rules

    Full text link
    Suppose each site on a one-dimensional chain with periodic boundary condition may take on any one of the states 0,1,...,n10,1,..., n-1, can you find out the most frequently occurring state using cellular automaton? Here, we prove that while the above density classification task cannot be resolved by a single cellular automaton, this task can be performed efficiently by applying two cellular automaton rules in succession.Comment: Revtex, 4 pages, uses amsfont

    OUTPUT SUPPLY AND INPUT DEMAND SYSTEM OF COMMERCIAL AND BACKYARD POULTRY PRODUCERS IN INDONESIA

    Get PDF
    Estimated Indonesian backyard and commercial broiler output supply and input demands from normalized quadratic function satisfy all theoretical properties (homogeneity, reciprocity, adding-up, symmetry, curvature). Elasticities have correct signs and are significant. Very inelastic supply explains strong border protection and casts doubt on long-term sustainability of import substitution policy.Demand and Price Analysis, Livestock Production/Industries,
    corecore