Let k be a positive integer and G a bipartite graph with bipartition (X,Y). A perfect 1-k matching is an edge subset M of G such that each vertex in Y is incident with exactly one edge in M and each vertex in X is inc...Let k be a positive integer and G a bipartite graph with bipartition (X,Y). A perfect 1-k matching is an edge subset M of G such that each vertex in Y is incident with exactly one edge in M and each vertex in X is incident with exactly k edges in M. A perfect 1-k matching is an optimal semi-matching related to the load-balancing problem, where a semi-matching is an edge subset M such that each vertex in Y is incident with exactly one edge in M, and a vertex in X can be incident with an arbitrary number of edges in M. In this paper, we give three sufficient and necessary conditions for the existence of perfect 1-k matchings and for the existence of 1-k matchings covering | X |−dvertices in X, respectively, and characterize k-elementary bipartite graph which is a graph such that the subgraph induced by all k-allowed edges is connected, where an edge is k-allowed if it is contained in a perfect 1-k matching.展开更多
In this paper, a necessary condition for a bipartite graph λK m,n to be K 1,k factorizable and a sufficient condition for kK m,n to have a K 1,k factorization whenever k is a prime numbe...In this paper, a necessary condition for a bipartite graph λK m,n to be K 1,k factorizable and a sufficient condition for kK m,n to have a K 1,k factorization whenever k is a prime number are given.展开更多
设 S 是 n 项可图序列, σ(S) 是 S 中的所有项之和, 设 H 是一个简单图, σ(H,n)是使得任意 n 项可图序列满足 σ(S) ≥ m , 则 S 有一个实现包含 H 作为子图的 m 的最小值, 本文给出了 σ(K p,1,1,...,1,n) 的...设 S 是 n 项可图序列, σ(S) 是 S 中的所有项之和, 设 H 是一个简单图, σ(H,n)是使得任意 n 项可图序列满足 σ(S) ≥ m , 则 S 有一个实现包含 H 作为子图的 m 的最小值, 本文给出了 σ(K p,1,1,...,1,n) 的下界并猜测对于所有的 n ≥ (t2 ) + 3p 此下界是可达到的.展开更多
文摘Let k be a positive integer and G a bipartite graph with bipartition (X,Y). A perfect 1-k matching is an edge subset M of G such that each vertex in Y is incident with exactly one edge in M and each vertex in X is incident with exactly k edges in M. A perfect 1-k matching is an optimal semi-matching related to the load-balancing problem, where a semi-matching is an edge subset M such that each vertex in Y is incident with exactly one edge in M, and a vertex in X can be incident with an arbitrary number of edges in M. In this paper, we give three sufficient and necessary conditions for the existence of perfect 1-k matchings and for the existence of 1-k matchings covering | X |−dvertices in X, respectively, and characterize k-elementary bipartite graph which is a graph such that the subgraph induced by all k-allowed edges is connected, where an edge is k-allowed if it is contained in a perfect 1-k matching.
文摘In this paper, a necessary condition for a bipartite graph λK m,n to be K 1,k factorizable and a sufficient condition for kK m,n to have a K 1,k factorization whenever k is a prime number are given.
文摘设 S 是 n 项可图序列, σ(S) 是 S 中的所有项之和, 设 H 是一个简单图, σ(H,n)是使得任意 n 项可图序列满足 σ(S) ≥ m , 则 S 有一个实现包含 H 作为子图的 m 的最小值, 本文给出了 σ(K p,1,1,...,1,n) 的下界并猜测对于所有的 n ≥ (t2 ) + 3p 此下界是可达到的.