17,135 research outputs found

    New Variants of Pattern Matching with Constants and Variables

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    Given a text and a pattern over two types of symbols called constants and variables, the parameterized pattern matching problem is to find all occurrences of substrings of the text that the pattern matches by substituting a variable in the text for each variable in the pattern, where the substitution should be injective. The function matching problem is a variant of it that lifts the injection constraint. In this paper, we discuss variants of those problems, where one can substitute a constant or a variable for each variable of the pattern. We give two kinds of algorithms for both problems, a convolution-based method and an extended KMP-based method, and analyze their complexity.Comment: 15 pages, 2 figure

    Extremal families of cubic Thue equations

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    We exactly determine the integral solutions to a previously untreated infinite family of cubic Thue equations of the form F(x,y)=1F(x,y)=1 with at least 55 such solutions. Our approach combines elementary arguments, with lower bounds for linear forms in logarithms and lattice-basis reduction

    A Note on TeV Cerenkov Events as Bose-Einstein Gamma Condensations

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    The idea that the TeV air showers, thought to be produced by >10 TeV gamma rays from Mrk 501, can be mimicked by coherent bunches of sub-TeV photons is reexamined, focusing on fundamental considerations. In particular, it is shown that the minimum spot size of the beam of pulsed TeV photons arriving at Earth is on the order of a few kilometers, unless a lens with certain characteristics is placed between the TeV laser and Earth. The viability of the laser production mechanism proposed by Harwit et al. (2000) is also reassessed.Comment: 4 page

    Galois correspondence for counting quantifiers

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    We introduce a new type of closure operator on the set of relations, max-implementation, and its weaker analog max-quantification. Then we show that approximation preserving reductions between counting constraint satisfaction problems (#CSPs) are preserved by these two types of closure operators. Together with some previous results this means that the approximation complexity of counting CSPs is determined by partial clones of relations that additionally closed under these new types of closure operators. Galois correspondence of various kind have proved to be quite helpful in the study of the complexity of the CSP. While we were unable to identify a Galois correspondence for partial clones closed under max-implementation and max-quantification, we obtain such results for slightly different type of closure operators, k-existential quantification. This type of quantifiers are known as counting quantifiers in model theory, and often used to enhance first order logic languages. We characterize partial clones of relations closed under k-existential quantification as sets of relations invariant under a set of partial functions that satisfy the condition of k-subset surjectivity. Finally, we give a description of Boolean max-co-clones, that is, sets of relations on {0,1} closed under max-implementations.Comment: 28 pages, 2 figure

    Dispositional Source of Job Satisfaction: The Role of Self-Deception

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    Despite providing strong indication that there is a dispositional source of job satisfaction, past research has not fully addressed the cardinal questions of how--or what--dispositions influence job satisfaction. This study suggests that self-deception may serve as an important psychological variable that partly explicates the dispositional source of job satisfaction. Using three sources of data obtained from a sample of university employees, our results indicated that employees who tend to engage in self-deception indeed experienced more satisfaction in their lives and with their jobs. Results also suggested that the relationship between subjective wellbeing and job satisfaction is reciprocal. All these findings were observed in a model including a significant link from affective disposition to subjective well-being. The results suggest that dispositional variables such as self-deception are important explanations of the dispositional source of job satisfaction
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