1,720,995 research outputs found
Quality of Information and Communications Technology - 17th International Conference on the Quality of Information and Communications Technology
No full textTen 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
Proceedings - 2021 IEEE/ACM 9th International Conference on Formal Methods in Software Engineering, FormaliSE 2021
No full textThe proceedings contain 13 papers. The topics discussed include: formal characterization and efficient verification of a biological robustness property; runtime verification under access restrictions; how much specification is enough? mutation analysis for software contracts; formally verified credentials management for industrial control systems; quantifying faultiness: what does it mean to have N faults?; methodology for specification and verification of high-level requirements with MetAcsl; and improved bounded model checking of timed automata
From Software Engineering to Formal Methods and Tools, and Back - Essays Dedicated to Stefania Gnesi on the Occasion of Her 65th Birthday
No full text
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
The Legacy of Stefania Gnesi: From Software Engineering to Formal Methods and Tools, and Back
No full textStefania Gnesi was born in Livorno in 1954. She studied Computer Science at the University of Pisa, where she graduated summa cum laude in 1978. During her studies at ISI, which was the University of Pisa’s Institute for Computer Science, a young discipline at that time, Stefania became interested in the continuing challenge associated with the production of software, namely to demonstrate that the developed software is actually doing what is expected to do, a challenge made harder in many cases by the fact that the expectations themselves are not precisely expressed. This has kept her busy ever since. To face this challenge her very first steps in research, towards the end of her university studies, of purely theoretical nature, proved very valuable. In a publication in the Journal of the ACM [63] (not bad for a first journal paper!), resulting from her thesis under the supervision of Prof. Ugo Montanari, it is shown that finding the solution of a dynamic programming problem in the form of polyadic functional equations is equivalent to searching a minimal cost path in an and/or graph with monotone cost functions. An important computational application of this result is that the solution of a system of functional equations can always be reduced to the problem of searching a minimal cost solution tree in an and/or graph
Application of Model Checking to Fault Tolerance Analysis
Full text linkA basic concept in modeling fault tolerant systems is that anticipated faults, being obviously outside of our control, may or may not occur. A fault tolerant system design can be proved to correctly behave under a given fault hypothesis, by proving the observational equivalence between the system design specification and the fault-free system specification. Additionally, model checking of a temporal logic formula which gives an abstract notion of correct behavior can be applied to verify the correctness of the design. Another activity that must be considered in fault tolerance is the issue of fault detection, since the existence of undetectable faults makes the system more vulnerable. The usage of model checking and temporal logic gives opportunities to better analyze the system behavior in presence of faults and to identify undetectable faults
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