Introduction Gene fixation in the sense that there is a single ancestor from which all the base pairs in all the copies of a gene in the population are descended only occurs in small (N < 1000) populations. In large populations (N > 1 000 000) crossing over (recombination) within the gene provides that there is an ancestral pool rather than a single ancestor of the gene. In the absence of recom...

Doppelgängers (or lookalikes) usually yield an increased probability of false matches in a facial recognition system, as opposed to random face image pairs selected for non-mated comparison trials. In this work, the impact doppelgängers on HDA Doppelgänger and Disguised Faces The Wild databases is assessed using state-of-the-art system. It found that doppelgänger very high similarity scores res...

Let (G;N) be a pair of groups. In this article, first we con-struct a relative central extension for the pair (G;N) such that specialtypes of covering pair of (G;N) are homomorphic image of it. Second, weshow that every perfect pair admits at least one covering pair. Finally,among extending some properties of perfect groups to perfect pairs, wecharacterize covering pairs of a perfect pair (G;N)...

We compare four similarity-based estimation methods against back-off and maximum-likelihood estimation methods on a pseudo-word sense disambiguation task in which we controlled for both unigram and bigram frequency. The similarity-based methods perform up to 40% better on this particular task. We also conclude that events that occur only once in the training set have major impact on similarity-...

Many fundamental questions in additive number theory (such as Goldbach’s conjecture, Fermat’s last theorem, and the Twin Primes conjecture) can be expressed in the language of sum and difference sets. As a typical pair of elements contributes one sum and two differences, we expect that |A−A| > |A+A| for a finite set A. However, in 2006 Martin and O’Bryant showed that a positive proportion of su...

We consider a random system of equations xi + xj = b(i,j)(mod 2), (xu ∈ {0, 1}, b(u,v) = b(v,u) ∈ {0, 1}), with the pairs (i, j) from E, a symmetric subset of [n]× [n]. E is chosen uniformly at random among all such subsets of a given cardinality m; alternatively (i, j) ∈ E with a given probability p, independently of all other pairs. Also, given E, Pr{be = 0} = Pr{be = 1} for each e ∈ E, indep...