منابع مشابه
Discrete Midpoint Convexity
For a function defined on a convex set in a Euclidean space, midpoint convexity is the property requiring that the value of the function at the midpoint of any line segment is not greater than the average of its values at the endpoints of the line segment. Midpoint convexity is a well-known characterization of ordinary convexity under very mild assumptions. For a function defined on the integer...
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In this paper we develop a theory of convexity for the lattice of integer points Z, which we call theory of discrete convexity. What subsets X ⊂ Z could be called ”convex”? One property seems indisputable: X should coincide with the set of all integer points of its convex hull co(X). We call such sets pseudo-convex. The resulting class PC of all pseudo-convex sets is stable under intersection b...
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A jump system, which is a set of integer lattice points with an exchange property, is an extended concept of a matroid. Some combinatorial structures such as the degree sequences of the matchings in an undirected graph are known to form a jump system. On the other hand, the maximum even factor problem is a generalization of the maximum matching problem into digraphs. When the given digraph has ...
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ژورنال
عنوان ژورنال: Mathematics of Operations Research
سال: 2020
ISSN: 0364-765X,1526-5471
DOI: 10.1287/moor.2018.0984