A Survey on Continuous Time Computations

We provide an overview of theories of continuous time computation. These theories allow us to understand both the hardness of questions related to continuous time dynamical systems and the computational power of continuous time analog models. We survey the existing models, summarizing results, and point to relevant references in the literature

Summary of the Heavy Flavor Working Group

During the last year many important results have been achieved in heavy flavour physics: New measurements of charm and beauty production have been performed at HERA and the Tevatron. A wealth of new spectroscopy data with several new, unexpected states in the charmonium and the D_s systems has been collected and b to d gamma transitions have been established. The oscillation frequency in the B_s Bbar_s is now measured, and mixing in the D0 D0bar system has been observed. Theoretical progress in the areas of open heavy flavour production, quarkonium production and decays, and multiquark spectroscopy has been presented at this workshop.Comment: 17 pages, 3 figures, to appear in the Proceedings of the XV International Workshop on Deep-Inelastic Scattering and Related Subjectes, DIS 2007, April 16--20, 2007, Munich, German

Who wrote this scientific text?

The IEEE bibliographic database contains a number of proven duplications with indication of the original paper(s) copied. This corpus is used to test a method for the detection of hidden intertextuality (commonly named "plagiarism"). The intertextual distance, combined with the sliding window and with various classification techniques, identifies these duplications with a very low risk of error. These experiments also show that several factors blur the identity of the scientific author, including variable group authorship and the high levels of intertextuality accepted, and sometimes desired, in scientific papers on the same topic

L'intertextualité dans les publications scientifiques

La base de données bibliographiques de l'IEEE contient un certain nombre de duplications avérées avec indication des originaux copiés. Ce corpus est utilisé pour tester une méthode d'attribution d'auteur. La combinaison de la distance intertextuelle avec la fenêtre glissante et diverses techniques de classification permet d'identifier ces duplications avec un risque d'erreur très faible. Cette expérience montre également que plusieurs facteurs brouillent l'identité de l'auteur scientifique, notamment des collectifs de chercheurs à géométrie variable et une forte dose d'intertextualité acceptée voire recherchée

NASA Langley Scientific and Technical Information Output: 1998

This document is a compilation of the scientific and technical information that the Langley Research Center has produced during the calendar year 1998. Included are citations for Technical Publications, Conference Publications, Technical Memorandums, Contractor Reports, Journal Articles and Book Publications, Meeting Presentations, Technical Talks, and Patents

Controle supervisório modular de sistemas híbridos

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.A presente tese de doutorado introduz uma metodologia de s´ýntese modular de supervisores para sistemas h´ýbridos que assegura um comportamento nao bloqueante e minimamente restritivo para o sistema sob supervisao. Os sistemas h´ýbridos considerados possuem dinamicas cont´ýnuas e dinamicas a eventos discretos, sendo que a dinamica discreta ´e definida por eventos gerados quando vari´aveis do espa¸co de estado cont´ýnuo alcan¸cam uma superf´ýcie de limiar, for¸cando entao transi¸coes no estado discreto. A dinamica cont´ýnua ´e determinada em fun¸cao do estado discreto atual do sistema. O objetivo de supervisao consiste em restringir a selecao de dinamicas cont´ýnuas de forma que a seq¨uencia de eventos esteja contida em um conjunto de seq¨uencias permitidas (especifica¸cao de controle). Os supervisores sao projetados (separadamente) usando uma abordagem puramente discreta. Este trabalho contribui ainda para a consolida¸cao da abordagem monol´ýtica de s´ýntese de supervisores para sistemas h´ýbridos e estende resultados anteriores atrav´es da considera¸cao de linguagens marcadas. A introdu¸cao do conceito de supervisor marcador para sistemas h´ýbridos permite que a determina¸cao do que deve ser uma tarefa fique a cargo do supervisor (da especifica¸cao). Nesta tese estuda-se tamb´em os problemas que surgem quando o projeto de supervisores (seja na abordagem monol´ýtica ou na abordagem modular) ´e feito com base em uma aproxima¸cao para o comportamento l´ogico do sistema h´ýbrido. Estabelece-se uma condi¸cao sob a qual se pode garantir que um supervisor sintetizado com base em um modelo aproximado para a planta h´ýbrida ´e tamb´em uma solu¸cao para o problema original. Exemplos sao utilizados para ilustrar a metodologia proposta e provas matem´aticas sao apresentadas para comprovar os resultados obtidos

Abstract Acceleration in Linear relation analysis (extended version)

Linear relation analysis is a classical abstract interpretation based on an over-approximation of reachable numerical states of a program by convex polyhedra. Since it works with a lattice of infinite height, it makes use of a widening operator to enforce the convergence of fixed point computations. Abstract acceleration is a method that computes the precise abstract effect of loops wherever possible and uses widening in the general case. Thus, it improves both the precision and the efficiency of the analysis. This research report gives a comprehensive tutorial on abstract acceleration: its origins in Presburger-based acceleration including new insights w.r.t. the linear accelerability of linear transformations, methods for simple and nested loops, recent extensions, tools and applications, and a detailed discussion of related methods and future perspectives. This is the long version of a paper under submission

WURC - Wood Ultrastructure Research Centre 1996-2007 Final report

The Wood Ultrastructure Research Centre (WURC) (http://www-wurc.slu.se) at the Swedish University of Agricultural Sciences (SLU) was established July 1st 1996. The partners in the initial framework of WURC were STFI-Packforsk (STFI-Packforsk), the Royal Institute of Technology (KTH) and Chalmers University of Technology (CTH) together with seven forest industry-related companies including: AssiDomän, Korsnäs, Mo och Domsjö, SCA, StoraEnso Södra Cell and Eka Chemicals. Through various divisions and mergers two further companies (Holmen, KappaKraftliner) joined WURC in phase 3 making a total of 9 supporting industries that remained with the Centre throughout its duration. The number of Universities involved in WURC´s activities expanded during later phases and members from the Departments of Biochemistry and Quantum Chemistry, Uppsala University as well from the Division of Chemistry, Karlstad University and Department of Natural Sciences, Örebro University also participated in the Centre’s activities. WURC´s mission has been to significantly increase the basic knowledge on wood and pulp fibres regarding their morphological ultrastructure, chemical structure and physical properties and to determine how these properties change after different chemical, mechanical and enzymatic treatments. The research conducted has been primarily fundamental in character and long-term and based on cooperation between Universities, industrial research Institutes and the R & D units of forest industry-related industries. During phases 3 and 4, WURC added more applied projects in-line with the industries request and began applying the knowledge gathered and the experimental toolbox developed from the more fundamental projects to specific industrial problems associated with Strength Delivery and Mechanical pulps). The establishment of WURC in Sweden has provided the opportunity for specialists from a number of widely different disciplines to cooperate and build a united body to carry out research on wood fibre structure mainly at the micro- and nano-levels; a research area which at the start of WURC was insignificantly developed in the country, but also elsewhere in comparison to the economic importance of the industry. During later phases, the nucleus of WURC´s activities between the University partners was concentrated to the UppsalaStockholm area. During phase 3, the number of projects in WURC´s portfolio was twenty reflecting a quadrupling from phases 1 - 2 and the interest in this type of research from both academia and industry alike. During phase 4, the number of projects was progressively reduced in-line with the running down and completing of the Centre´s activities. WURC has attained a high level of competence in the area of wood fibre ultrastructure during its ca 11 years existence. It has become internationally recognized (e.g. by annual international conferences, involvement in European COST actions, peer reviewed publications and symposium presentations, exchange of guest researchers etc) as a major Centre of Excellence interacting with the Swedish pulp and paper industry. By nature of its research, competence and critical mass (e.g. 50-60 people were involved wholly or part-time in WURC´s activities during years 2003/4) (phase 3), WURC was quite unique in the world. During the last 11 years, WURC scientists have been involved in over 300 scientific papers and symposia presentations and at closing, 17 PhD and 7 Licentiate graduates (wholly or partly financed) had successfully defended their theses within the Centre. The Centre has further organized 10 international, 11 major internal industry/academia interactive seminars and numerous other industry-academia project-group meetings through its era. The Centre has had an international advisory group of leading scientists that have further been active in advising WURC´s management, vetting project developments and directions during annual seminars. WURC has used a working model based on interactions between industry and academia at all levels throughout its phases. Initially WURC´s board was comprised of representatives from member companies, VINNOVA, SLU and later on STFI-Packforsk. The chairman has been from STFI-Packforsk and the directors from StoraEnso (1996-1998), SLU (1998-2007) and vice-director from Sveaskog (2001-2007). WURC has had an Industrial Advisory (Reference) Group (IRG) comprised of representatives from all the supporting companies and together with WURC´s management team used to vet all project proposals for both academic and industrial possibilities. During phases 3/4, the group was very active in the establishment and running of industry orientated projects involving industry project leaders. The group has monitored the progress of the WURC projects and provided specialized fibre materials (e.g. chemical/mechanical pulps, wood samples) for the different projects. WURC has had a primary focus on fundamental research on fibre ultrastructure, thus the major major added benefits of the Centre has been the creation and development of interdisciplinary interactions between the Swedish pulp and paper industry and WURC scientists in a research area of common interest. During its later phases, WURC revised its major research focus to include industrial orientated projects concerning Pulp 2000, Strength Delivery and Mechanical pulps. Research of the more applied nature comprised ca 35 % of WURC´s total budget in phases 3/4 and within this group; the majority of the in-kind contributions from WURC´s industrial partners (ca 36 %) were located. During later phases, the in kind contributions from industry/University also exceeded that contracted. The challenge for WURC´s future has been to retain its academic standard at international level and at the same time further develop the industrial applications and significance of its knowledge. Great efforts were made to secure financing for continuation of the Centre after the VINNOVA Competence Centre era in 2007. This process was initiated already Autumn 05 and progressed through board activities, numerous management meetings, a writing of gaps in our knowledge document by WURC´s scientists and areas of research priority given by WURC´s member companies. This culminated in a successful application to VINNOVAs “Branschforsknings fund” February 08 for program entitled Process and product developments through unique knowledge of wood fibre ultrastructure (2008- 2011) (WURC INNOVATION). The program will include strong collaboration between University/Institute partners SLU, STFI-Packforsk, KTH and Mid-Sweden University with member companies EkaChemicals, Holmen, SCA, SmurfitKraftliner, StoraEnso and Södra Cell. Securement of the new grant with continued industry support is a testimony to the success WURC has achieved