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EJC
2008
13 years 8 months ago
2008
3 Motivated by the works of Ngo and Du [H. Ngo, D. Du, A survey on combinatorial group testing 4 algorithms with applications to DNA library screening, DIMACS Series in Discrete Ma...
EJC
2008
13 years 8 months ago
2008
A graph may be the Kronecker cover in more than one way. In this note we explore this phenomenon and apply it to show that the minimal common cover of two graphs need not be uniqu...
EJC
2008
13 years 8 months ago
2008
We study restricted homomorphism dualities in the context of classes with bounded expansion. This presents a generalization of restricted dualities obtained earlier for bounded deg...
EJC
2008
13 years 8 months ago
2008
In this paper, we compute the congruences of Catalan and Motzkin numbers modulo 4 and 8. in particular, we prove the conjecture proposed by Deutsch and Sagan that no Motzkin numbe...
EJC
2008
13 years 8 months ago
2008
Abstract. We prove a general theorem on semigroup functions that implies characterizations of graph partition functions in terms of the positive semidefiniteness (`reflection posit...