We study the generating function for the number of involutions on n letters containing exactly r ≥ 0 occurrences of 3412. It is shown that finding this function for a given r amounts to a routine check of all involutions on 2r + 1 letters. 2000 Mathematics Subject Classification: Primary 05A05, 05A15; Secondary 05C90

Recent work has achieved promising retrieval performance using distance between term occurrences as a primary estimator of document relevance. A major bene t of this approach is that relevance scoring does not rely on collection frequency statistics. A theoretical framework for lexical spans is now proposed which encompasses these approaches and suggests a number of important directions for fut...

This paper is concerned with palindromes occurring in characteristic Sturmian words cα of slope α, where α ∈ (0, 1) is an irrational. As cα is a uniformly recurrent infinite word, any (palindromic) factor of cα occurs infinitely many times in cα with bounded gaps. Our aim is to completely describe where palindromes occur in cα. In particular, given any palindromic factor u of cα, we shall estab...

Spindles - a hallmark of stage II sleep - are a transient oscillatory phenomenon in the EEG believed to reflect thalamocortical activity contributing to unresponsiveness during sleep. Currently spindles are often classified into two classes: fast spindles, with a frequency of around 14 Hz, occurring in the centro-parietal region; and slow spindles, with a frequency of around 12 Hz, prevalent in...

We present a tool, called ILIMP, which takes as input a raw text in French and produces as output the same text in which every occurrence of the pronoun il is tagged either with tag [ANA] for anaphoric or [IMP] for impersonal or expletive. This tool is therefore designed to distinguish between the anaphoric occurrences of il, for which an anaphora resolution system has to look for an antecedent...

This is the second article on regular expression quantifiers. [4] introduced the quantifiers m to n occurrences and optional occurrence. In the sequel, the quantifiers: at least m occurrences and positive closure (at least 1 occurrence) are introduced. Notation and terminology were taken from [8], several properties of regular expressions from [7]. The notation and terminology used here are int...

Similar to AC system, the insulation system of DC system also gets affected. The HVDC station is a challenging environment for measurement of partial discharge level due to very high interference levels caused from the switching of thyristor-controlled converters. There is also significant interference from external air-corona due to high electric stress at the surface of conductors and hardwar...

We count the number of distinct (scattered) subwords occurring in the base-b expansion of the nonnegative integers. More precisely, we consider the sequence (Sb(n))n≥0 counting the number of positive entries on each row of a generalization of the Pascal triangle to binomial coefficients of base-b expansions. By using a convenient tree structure, we provide recurrence relations for (Sb(n))n≥0 le...

Vector space models (VSMs) are often employed as mathematical representations of documents for tasks like indexing, information retrieval (IR), filtering and others, where documents are represented as vectors of their index terms or keywords. In a vector space representation, interrelations between individual terms in the vector are not captured. IR tasks like classification or search rely on t...

Consider a given pattern H and a random text T of length n. We assume that symbols in the text occur independently, and various symbols have different probabilities of occurrence (l.e., the so called asymmetric Bernoulli modeQ. We are concerned with the probability of exactly T occurrences of H in the text T. We derive the generating function of this probability, and show that asymptotically it...