1,720,977 research outputs found
Rank and simulation: the well-founded case
Full text linkWe consider the algorithmic problem of computing the maximal simulation preorder (and quotient) on acyclic labelled graphs. The acyclicity allows to exploit an inner structure on the set of nodes, that can be processed in stages according to a set-theoretic notion of rank. This idea, previously used for bisimulation computation, on the one hand improves on the performances of the ensuing procedure and, on the other hand, gives to the solution an orderly iterative flavour making the algorithmic idea more explicit. The computational complexity achieved is good as we obtain the best performing algorithm for simulation computation on acyclic graphs, in both time and space. © The Author, 2013. Published by Oxford University Press. All rights reserved
Rank-Based Simulation on Acyclic Graphs
Full text linkThe simulation preorder is widely used both as a behavioral relation in concurrent systems, and as an abstraction tool to reduce the state space in model checking, were memory requirement is clearly a critical issue. Therefore, in this context a simulation algorithm should address both time and space efficiency. In this paper, we rely on the notion of rank to design an efficient simulation algorithm. It turns out that such algorithm outperforms-both in terms of time and in terms of space-the best simulation algorithms in the literature, on the class of acyclic graphs
Il consenso informato nel rapporto medico-paziente, con particolare riferimento ai suoi aspetti peculiari in campo geriatrico
No full textScalable Energy Games Solvers on GPUs
No full textModeling the consumption of limited resources, e.g., time or energy, plays a central role in the design of reactive systems such as embedded controllers. To this aim, quantitative objectives are defined on game arenas that can be easily modeled as weighted graphs. Instances of these games, called energy games, can be solved in O(|E ||V |W) where W is the maximum weight. Recent work has demonstrated that sequential implementations hardly solve practical instances. Furthermore, emerging approaches, that have investigated the parallelism of CPUs multi-core and GPU for solving the initial credit problem for energy games, still perform poorly due to the non-trivial characteristics of these graphs. In the present work, we first describe a revised version of the algorithm on a multi-core CPU that obtains a faster convergence time on real-world graphs with up to 30x against serial implementation by showing good scalability overall. Second, we provide a new GPU-based parallel implementation based on warp-level primitives that allow to reduce the time-to-solution on several instances with up to 3.6x of speed-up against traditional parallel vertex-based approaches. We also discuss a methodology to build synthetic energy games to validate the scalability of parallel algorithms on two totally different settings
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
Hybrid automata in systems biology
No full textIn this chapter, the authors discuss a number of formal tools collectively driving them to Hybrid Automata. Automata have a long and rich history in computer science, and they have been used in a variety of ways to render (formally) many basic and natural ideas. The authors introduce first-order languages and theories, and report on some decidability results over them. They also discuss possible usages of the simple formalism of finite state automata. A possible way to model real-world systems is to abstract all the quantitative part of their evolution and exclusively focus on the sequences of discrete events that they produce and that led to some outcome. The authors focus their attention on the use of hybrid automata for modelling quite "simple" biological systems. They also introduce the two final "ingredients" of their discussion: Time and Uncertainty. The initial time instants of simple, finite-state automata models are defined by the occurrence of events
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