1,720,970 research outputs found
An approach for the automatic verification of blockchain protocols: the Tweetchain case study
Get PDFThis paper proposes a model-driven approach for the security modelling and analysis of blockchain based protocols. The modelling is built upon the definition of a UML profile, which is able to capture transaction-oriented information. The analysis is based on existing formal analysis tools. In particular, the paper considers the Tweetchain protocol, a recent proposal that leverages online social networks, i.e., Twitter, for extending blockchain to domains with small-value transactions, such as IoT. A specialized textual notation is added to the UML profile to capture features of this protocol. Furthermore, a model transformation is defined to generate a Tamarin model, from the UML models, via an intermediate well-known notation, i.e., the Alice &Bob notation. Finally, Tamarin Prover is used to verify the model of the protocol against some security properties. This work extends a previous one, where the Tamarin formal models were generated by hand. A comparison on the analysis results, both under the functional and non-functional aspects, is reported here too
Towards a UML profile for data intensive applications
No full textData intensive applications that leverage Big Data technologies are rapidly gaining market trend. However, their design and quality assurance are far from satisfying software engineers needs. In fact, a CapGemini research shows that only 13% of organizations have achieved full-scale production for their Big Data implementations. We aim at addressing an early design and a quality evaluation of data intensive applications, being our goal to help software engineers on assessing quality metrics, such as the response time of the application. We address this goal by means of a quality analysis tool-chain. At the core of the tool, we are developing a Profile that converts the Unified Modeling Language into a domain specific modeling language for quality evaluation of data intensive applications
Security modelling and formal verification of survivability properties: Application to cyber–physical systems
No full textThe modelling and verification of systems security is an open research topic whose complexity and importance needs, in our view, the use of formal and non-formal methods. This paper addresses the modelling of security using misuse cases and the automatic verification of survivability properties using model checking. The survivability of a system characterises its capacity to fulfil its mission (promptly) in the presence of attacks, failures, or accidents, as defined by Ellison. The original contributions of this paper are a methodology and its tool support, through a framework called surreal. The methodology starts from a misuse case specification enriched with UML profile annotations and obtains, as a by-product, a survivability assessment model (SAM). Using predefined queries the survivability properties are proved in the SAM. A total of fourteen properties have been formulated and also implemented in surreal, which encompasses tools to model the security specification, to create the SAM and to prove the properties. Finally, the paper validates the methodology and the framework using a cyber–physical system (CPS) case study, in the automotive field
Security modelling and formal verification of survivability properties: Application to cyber–physical systems
Get PDFThe modelling and verification of systems security is an open research topic whose complexity and importance needs, in our view, the use of formal and non-formal methods. This paper addresses the modelling of security using misuse cases and the automatic verification of survivability properties using model checking. The survivability of a system characterises its capacity to fulfil its mission (promptly) in the presence of attacks, failures, or accidents, as defined by Ellison. The original contributions of this paper are a methodology and its tool support, through a framework called surreal. The methodology starts from a misuse case specification enriched with UML profile annotations and obtains, as a by-product, a survivability assessment model (SAM). Using predefined queries the survivability properties are proved in the SAM. A total of fourteen properties have been formulated and also implemented in surreal, which encompasses tools to model the security specification, to create the SAM and to prove the properties. Finally, the paper validates the methodology and the framework using a cyber–physical system (CPS) case study, in the automotive field
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Towards a model-driven engineering approach for the assessment of non-functional properties using multi-formalism
Get PDFModel-driven techniques can be used to automatically produce formal models from different views of a system realised by using several modelling languages and notations. Specifications are transformed into formal models so facilitating the analysis of complex system for design, validation or verification purposes. However, no single formalism suits for representing all system’s views. In particular, the assessment of non-functional properties often requires integrated modelling approaches. The ultimate goal of the research work described in this paper is to develop a comprehensive, theoretical and practical framework able to support the development and the integration of new or existing model-driven approaches for the automatic generation of multi-formalism models. This paper defines the core theoretical ideas on which the framework is based and demonstrates their concrete applicability to the development of a multi-formalism approach for performability assessment
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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