FEASIBILITY OF INTEGER KNAPSACKS∗ ISKANDER ALIEV† AND MARTIN HENK‡ Abstract. Given a matrix A ∈ Zm×n satisfying certain regularity assumptions, we consider the set F(A) of all vectors b ∈ Zm such that the associated knapsack polytope P (A, b) = {x ∈ R≥0 : Ax = b} contains an integer point. When m = 1 the set F(A) is known to contain all consecutive integers greater than the Frobenius number ass...

Introduction. Several authors have proved theorems of the type: The "structure" of a certain class of transformations defined on a "suitable" space A to a fixed "suitable" space B "determines" the space A. As examples, we have: Banach [3, p. 170, see also 6, 7, 13] i The Banach space of all real, continuous functions defined on a compact metric space A "determines" A. Eidelheit [5, see also 2, ...

A modular and hierarchical self-assembly strategy using block copolymer blends (AB/B’C) with tunable supramolecular interactions is reported. By combining supramolecular assembly of hydrogenbonding units with controlled phase separation of diblock copolymers, highly ordered square arrays or hexagonal arrays of cylindrical domains were obtained formixtures of poly(ethylene oxide)-b-poly(styrene-...

Let be the number of ordered pairs of paths in the plane, with unit steps E or N, that intersect k times in which the first path ends at the point (r,n-r) and the second path ends at the point (s,n-s). Let and We study the numbers , , , and , prove several simple relations among them, and derive a simpler formula for than appears in [1].

For given finite (unordered) graphs G and H, we examine the existence of a Ramsey graph F for which the strong Ramsey arrow F −→ (G)r holds. We concentrate on the situation when H is not a complete graph. The set of graphs G for which there exists an F satisfying F −→ (G)2 2 (P2 is a path on 3 vertices) is found to be the union of the set of chordal comparability graphs together with the set of...

SB (a, b) = { √ b2−a2 cos−1(a/b) , a < b , √ a2−b2 cosh−1(a/b) , a > b . In this paper, we find the greatest values α1, α2, α3 and α4, and the least values β1, β2, β3 and β4 such that the double inequalities α1SAH(a, b) + (1 − α1)C(a, b) < A(a, b) < β1SAH(a, b) + (1 − β1)C(a, b), α2SHA(a, b) + (1 − α2)C(a, b) < A(a, b) < β2SHA(a, b) + (1 − β2)C(a, b), α3SCA(a, b) + (1 − α3)H(a, b) < A(a, b) < β...

Let [n] denote an n-set. A subset,) of [n] i from j if i and j t/:. 5'. A collection of k-sets n called (n, k) completely if, for each ordered pair j) E [n] x [71,] with i n which i from j. Let denote the size of a smallest (71" k) completely Amongst other things, it will be shown that R( 71" k) for n > except when n (Hl) 1, and R(71" k) k + 1 for G) n k 2 /2. These results build on and extend ...

We consider the partially ordered set ([k]", <), which is defined as n-th product of the chain [k] = {0,1, 2 . . . . . k 1}, and study pairs (A, B) of incomparable sets A, B ~ [k]", that is, a :g b, a :~ b for all a ~ A, b ~ B or (in short notation) A : :~ B. We are concerned with the growth of the functions f,: {0, 1 . . . . . k ~} ---, {0, 1 . . . . . k"}, n ~ N, defined by f,(ct) = max{IN: A...

The concepts of tropical semiring and tropical hypersurface, are extended to the case of an arbitrary ordered group. Then, we define the tropicalization of a polynomial with coefficients in a Krull-valued field. After a close study of the properties of the operator “tropicalization” we conclude with an extension of Kapranov’s theorem to algebraically closed fields together with a valuation over...