Growth rate for the expected value of a generalized random Fibonacci sequence

A random Fibonacci sequence is defined by the relation g_n = | g_{n-1} +/- g_{n-2} |, where the +/- sign is chosen by tossing a balanced coin for each n. We generalize these sequences to the case when the coin is unbalanced (denoting by p the probability of a +), and the recurrence relation is of the form g_n = |\lambda g_{n-1} +/- g_{n-2} |. When \lambda >=2 and 0 < p <= 1, we prove that the expected value of g_n grows exponentially fast. When \lambda = \lambda_k = 2 cos(\pi/k) for some fixed integer k>2, we show that the expected value of g_n grows exponentially fast for p>(2-\lambda_k)/4 and give an algebraic expression for the growth rate. The involved methods extend (and correct) those introduced in a previous paper by the second author

FibLSS: A scalable label storage scheme for dynamic XML updates

Dynamic labeling schemes for XML updates have been the focus of significant research activity in recent years. However the label storage schemes underpinning the dynamic labeling schemes have not received as much attention. Label storage schemes specify how labels are physically encoded and stored on disk. The size of the labels and their logical representation directly influence the computational costs of processing the labels and can limit the functionality provided by the dynamic labeling scheme to an XML update service. This has significant practical implications when merging XML repositories such as clinical studies. In this paper, we provide an overview of the existing label storage schemes. We present a novel label storage scheme based on the Fibonacci sequence that can completely avoid relabeling existing nodes under dynamic insertions. Theoretical analysis and experimental results confirm the scalability and performance of the Fibonacci label storage scheme in comparison to existing approaches

\uab Les linguistiques du d\ue9tachement. Actes du Colloque International de Nancy (7-9 juin 2006) \ubb. Collection SCIENCES POUR LA COMMUNICATION, Peter Lang, Berne, 2009, N\ub0 87, p. 595.

Le num\ue9ro 87 de la collection SCIENCES POUR LA COMMUNICATION est consacr\ue9 \ue0 la publication des actes du Colloque International \uab Les linguistiques du d\ue9tachement \ubb qui s\u2019est tenu \ue0 Nancy les 7-9 juin 2006. Ce colloque, dont l\u2019organisation a \ue9t\ue9 assur\ue9e par l\u2019ATILF (Analyse et Traitement Informatique de la Langue Fran\ue7aise, CNRS et Nancy-Universit\ue9s) et par le laboratoire CRISCO (Centre de Recherches Inter-langues sur la Signification en Contexte, Universit\ue9 de Caen), avait le but de r\ue9unir tous les chercheurs s\u2019int\ue9ressant aux structures \uab \ue0 d\ue9tachement \ubb, c\u2019est-\ue0-dire aux phrases dites DISLOQU\uc9ES ou SEGMENT\uc9ES (dislocation \ue0 droite ou \ue0 gauche), mais aussi \ue0 l\u2019apposition et \ue0 d\u2019autres formes de discontinuit\ue9 syntaxique. S\u2019agissant de constructions qui se r\ue9alisent, avec de fortes ressemblances, dans l\u2019ensemble des syst\ue8mes linguistiques, les organisateurs ont veill\ue9 \ue0 ce que la plus grande vari\ue9t\ue9 de langues soit repr\ue9sent\ue9e, souhaitant aboutir, au-del\ue0 des difformit\ue9s th\ue9oriques et terminologiques, \ue0 une typologie des constructions \uab \ue0 d\ue9tachement \ubb. Les actes du colloque r\ue9pertorient donc tant les \ue9tudes portant sur l\u2019\ue9crit que celles sur l\u2019oral conversationnel, et pr\ue9sentent, en m\ueame temps, un \ue9chantillonnage repr\ue9sentatif des diff\ue9rents niveaux d\u2019analyse (syntaxique, s\ue9mantique, pragmatique, prosodique), du point de vue adopt\ue9 (synchronique ou diachronique) et des mod\ue8les th\ue9oriques de r\ue9f\ue9rence. En raison de leur grand nombre, les 41 contributions seront r\ue9parties ici par grandes aires th\ue9matiques ainsi que par niveau de saillance et/ou de repr\ue9sentativit\ue9 \ue0 l\u2019int\ue9rieur de chaque aire