1,721,055 research outputs found
Axiomatizing ST Bisimulation for a Process Algebra with Recursion and Action Refinement (Extended Abstract)
No full text) 1 Mario Bravetti, Roberto Gorrieri Dipartimento di Scienze dell'Informazione Universit`a di Bologna Mura Anteo Zamboni 7, 40127 Bologna, Italy E-mail: fbravetti, [email protected] Abstract Due to the complex nature of bisimulation equivalences which express some form of history dependence, it turned out to be problematic to axiomatize them for non trivial classes of systems. Here we introduce the idea of "compositional levelwise renaming" which gives rise to the new possibility of axiomatizing the class of history dependent bisimulations with slight modifications to the machinery for standard bisimulation. We propose two techniques, which are based on this idea, in the special case of the ST semantics, defined for terms of a process algebra with recursion. The first technique, which is more intuitive, is based on dynamic names, allowing weak ST bisimulation to be decided and axiomatized for all processes that possess a finite state interleaving semantics. The second techn..
Reduction Semantics in Markovian Process Algebra
Full text linkInternational audienceMarkovian process algebras allow for performance analysis by automatic generation of Continuous Time Markov Chains. The inclusion of exponential distribution rate information in process algebra terms, however, causes non trivial issues to arise in the definition of their semantics. As a consequence, technical settings previously considered do not make it possible to base Markovian semantics on directly computing reductions between communicating processes: this would require the ability to readjust processes, i.e. a commutative and associative parallel operator and a congruence relation on terms enacting such properties. Semantics in reduction style is, however, often used for complex languages, due to its simplicity and conciseness. In this paper we introduce a new technique based on stochastic binders that allows us to define Markovian semantics in the presence of such a structural congruence. As application examples, we define the reduction semantics of Markovian versions of the π-calculus, considering both the cases of Markovian durations: being additional standalone prefixes (as in Interactive Markov Chains) and being, instead, associated to standard synchro-nizable actions, giving them a duration (as in Stochastic π-calculus). Notably, in the latter case, we obtain a "natural" Markovian semantics for π-calculus (CCS) parallel that preserves, for the first time, its associativity. In both cases we show our technique for defining reduction semantics to be correct with respect to the standard Markovian one (in labeled style) by providing Markovian extensions of the classical π-calculus Harmony theorem
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Axiomatizing maximal progress and discrete time
Full text linkMilner’s complete proof system for observational congruence is crucially based on the possibility to equate τ divergent expressions to non-divergent ones by means of the axiom recX.(τ.X + E) = recX.τ.E. In the presence of a notion of priority, where, e.g., actions of type δ have a lower priority than silent τ actions, this axiom is no longer sound. Such a form of priority is, however, common in timed process algebra, where, due to the interpretation of δ as a time delay, it naturally arises from the maximal progress assumption. We here present our solution, based on introducing an auxiliary operator pri(E) defining a “priority scope”, to the long time open problem of axiomatizing priority using standard observational congruence: we provide a complete axiomatization for a basic process algebra with priority and (unguarded) recursion. We also show that, when the setting is extended by considering static operators of a discrete time calculus, an axiomatization that is complete over (a characterization of) finite-state terms can be developed by re-using techniques devised in the context of a cooperation with Prof. Jos Baeten
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
