منابع مشابه
On Cartesian skeletons of graphs
Under suitable conditions of connectivity or non-bipartiteness, each of the three standard graph products (the Cartesian product, the direct product and the strong product) satisfies the unique prime factorization property, and there are polynomial algorithms to determine the prime factors. This is most easily proved for the Cartesian product. For the other products, current proofs involve a no...
متن کاملOn Herbrand Skeletons
Herbrand's theorem plays an important role both in proof theory and in computer science. Given a Herbrand skeleton, which is basically a number specifying the count of disjunctions of the matrix, we would like to get a computable bound on the size of terms which make the disjunction into a quasitautology. This is an important problem in logic, speciically in the complexity of proofs. In compute...
متن کاملOn growing connected β-skeletons
A β-skeleton, β ≥ 1, is a planar proximity undirected graph of an Euclidean points set, where nodes are connected by an edge if their lune-based neighbourhood contains no other points of the given set. Parameter β determines the size and shape of the lune-based neighbourhood. A β-skeleton of a random planar set is usually a disconnected graph for β > 2. With the increase of β, the number of edg...
متن کاملPhylogeny and temporal diversification of darters (Percidae: Etheostomatinae).
Discussions aimed at resolution of the Tree of Life are most often focused on the interrelationships of major organismal lineages. In this study, we focus on the resolution of some of the most apical branches in the Tree of Life through exploration of the phylogenetic relationships of darters, a species-rich clade of North American freshwater fishes. With a near-complete taxon sampling of close...
متن کاملeffect of oral presentation on development of l2 learners grammar
this experimental study has been conducted to test the effect of oral presentation on the development of l2 learners grammar. but this oral presentation is not merely a deductive instruction of grammatical points, in this presentation two hypotheses of krashen (input and low filter hypotheses), stevicks viewpoints on grammar explanation and correction and widdowsons opinion on limited use of l1...
15 صفحه اولذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the United States National Museum
سال: 1885
ISSN: 0096-3801
DOI: 10.5479/si.00963801.8-484.68