1,721,048 research outputs found
Some Concurrency Models In A Categorical Framework (Extended Abstract)
No full textCHIARA BODEI Dipartimento di Informatica, Universit`a di Pisa Corso Italia, 40, I-56125 Pisa, Italy [email protected] The paper defines a taxonomy of concurrent models. Concurrent models are seen as categories and passages between models as functors. We particularly care about the notions of concurrency, causal and temporal dependencies and their possible different perception. According to the chosen model, only part of these notions are, indeed, relevant and recoverable from the observation of a concurrent system. 1 Introduction In the last decades a great deal of efforts have been devoted to study suitable models in order to describe concurrent and distributed systems and to understand their semantics. Several and heterogeneous models have been introduced, each focusing on a peculiar aspect of concurrency and laying at a particular description level. Categories, as in 1;2;3 , can help in classifying the different models and in formally characterizing the passages between them. ..
Static Evidences for Attack Reconstruction
No full textControl Flow Analysis (CFA) has been proven successful for the analysis of cryptographic protocols. Due to its over-approximative nature, the absence of detected flaws implies their absence also at run time, while their presence only says that there is the possibility for flaws to occur. Nevertheless, the static detection of a flaw can be considered as a warning bell that alerts against a possible attack, of which the flaw is the result. Reconstructing the possible attack leading to the detected flaw is not trivial, though. We propose a CFA enriched with causal information that accounts for attacker activity. In case a flaw is predicted, the causal information provides a sort of climbing holds that can be escalated to reconstruct the attack sequence leading to the flaw
1839: la prima Riunione degli Scienziati Italiani Atti della giornata di studi tenuta a 180 anni di distanza
No full textAtti della giornata dedicata alle celebrazioni del primo convegno degli scienziati italiani svoltosi a Pisa nel 1839, a 180 anni di distanza
Pierpaolo Degano
No full textWe present here a laudatio that illustrates the distinguished career and the main scientific contributions of Pierpaolo Degano, in the volume of essays dedicated to him, on the occasion of his 65th birthday
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
Authentication Primitives for Refining Protocol Specifications
Full text linkWe propose a way to abstract from various specifications of authentication and to obtain idealized protocols "secure by construction". This feature enables us to prove that a cryptographic protocol is the correct implementation of the corresponding abstract protocol. Our proposal relies on the combination of two authentication primitives, proposed by the authors in to a simplified version of the spi calculus
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
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