1,721,082 research outputs found
Temporal Logic Verification of LOTOS Specifications Using Abstract Interpretation
No full textInterpretation CNUCE Internal Report num. C94-19, Oct. 1994 Alessandro Fantechi y Stefania Gnesi z Diego Latella x Abstract In [6, 5] a technique for the automatic derivation of an Abstract Interpretation Domain for (the Abstract Data Types part) of LOTOS specifications has been proposed. In this paper we present an abstract model of process semantics, Abstract Trace Semantics, which is built on top of the above mentioned Abstract Interpretation Domain and which we use as a model for an abstract interpretation of a linear time temporal logics. Both Abstract Trace Semantics and the abstract interpretation of the satisfiability relation are proven correct w.r.t. their concrete counterparts. The main advantage of the proposed approach stems from the fact that it allows to completely automatize the verification that a formula is satisfied by a process in the abstract domain. When the formula is satisfied by the process in the abstract domain, then the correctness theorem guarantee..
Ten Years of Self-adaptive Systems: From Dynamic Ensembles to Collective Adaptive Systems
No full textSelf-adaptive systems have been introduced to manage situations where software systems operate under continuous perturbations due to the unpredicted behaviors of their clients and the occurrence of exogenous changes in the environment in which they operate. Adaptation is triggered by the run-time occurrence of an extraordinary circumstance, and it is handled by an adaptation process that involves components affected by the issue, and is able to handle the run-time modification of the structure and behavior of a running system. In this paper we report our experience gained in the last 10 years on models, techniques and applications in the field of self-adaptation. We present the various steps taken by means of a formal framework introduced to characterize the different aspects of an ensemble-based software engineering approach. We present (i) how to model dynamic ensembles using typed graph grammars, (ii) how to specialize and re-configure ensembles and, (ii) how to manage collective adaptations in an ensemble. All these aspects have been part of our research on self-adaptation and have been used to specify and deploy concrete solutions in different application domains
An Executon Environment for the Formal Definiton of Ada
No full textThis work proposes an execution environment for the formal definition of Ada, as produced by the project "The Draft Formal Definition of ANSI/MIL-STD-1815A Ada". The environment is based on a logic programming approach, that is the translation of the formal definition itself in an executable logic program. The aim of this construction is to evaluate the feasibility and the effectiveness of an interpreter based on the formal definition.
The use of novel techniques like metaprogramming and partial evaluation in order to improve the modularity and the efficiency of the system is also explored
From Software Engineering to Formal Methods and Tools, and Back - Essays Dedicated to Stefania Gnesi on the Occasion of Her 65th Birthday
No full textModel Checking of Non-Finite State Processes by Finite Approximations
No full textIn this paper we present a verification methodology, using an action-based logic, able to check properties for full CCS terms, allowing also verification on infinite state systems. Obviously, for some properties we are only able to give a semidecision procedure. The idea is to use (a sequence of) finite state transition systems which approximate the, possibly infinite state, transition system corresponding to a term. To this end we define a particular notion of approximation, which is stronger than simulation, suitable to define and prove liveness and safety properties of the process terms
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
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