1,721,165 research outputs found
The impact of physical processes on the estimation of the ages of asteroid families
No full textOne of the methods used to estimate the ages of the asteroid families is based on the interpretation of the distribution of the
sizes versus orbital semimajor axes of their members as the result of their post-formation dynamical evolution. The fundamental
hypothesis is that the present distribution of the semimajor axes is essentially the product of the Yarkovsky effect. On the other
hand, the observable features of the asteroid families can be affected by several physical and dynamical processes. In this paper,
we discuss the role of: (1) the initial distribution of the ejection velocities at the time of the primordial break-up event; (2) the
possible correlations between the family members ejection direction and the orientation of the rotational axis (which the direction
of the Yarkovsky semimajor axis drift depends on); (3) the gravitational reaccumulation of the parent body fragments during
the ballistic phase of the formation process; and (4) the collisional re-orientation of the spin axes during the post-formation
evolution phase. We show how each of these mechanisms affects the determination of the ages of the asteroid families, and what
additional information can be inferred regarding some aspects of the collisional evolution of the rotation axes
Intents Analysis of Android Apps for Confidentiality Leakage Detection
No full textIntents are Android’s intra- and inter-application communication mechanism. They specify an action to perform, with extra data, and are sent to a receiver component or broadcast to many components. Components, in the same or in a distinct app, receive the intent if they are available to perform the desired action. Hence, a sound static analyzer must be aware of information flows through intents. That can be achieved by considering intents as both source (when reading) and sink (when writing) of confidential data. But this is overly conservative if the intent stays inside the same app or if the set of apps installed on the device is known in advance. In such cases, a sound approximation of the flow of intents leads to a more precise analysis. This work describes SDLI, a novel static analyzer that, for each app, creates an XML summary file reporting a description of the tainted information in outwards intents and of the intents the app is available to serve. SDLI discovers confidential information leaks when two apps communicate, by matching their XML summaries, looking for tainted outwards intents of the first app that can be inwards intents of the second app. The tool is implemented inside Julia, an industrial static analyzer. On the DroidBench test cases, its shows a precision higher than 75%. On some popular apps from the Google Play marketplace, it spots inter-apps leaks of confidential data, hence showing its practical effectiveness
Finding the shortest path with PesCa: A tool for network reconstruction
Full text linkThe growing dimension and complexity of the available experimental data generating biological networks have increased the need for tools that help in categorizing nodes by their topological relevance. Here we present CentiScaPe, a Cytoscape app specifically designed to calculate centrality indexes used for the identification of the most important nodes in a network. CentiScaPe is a comprehensive suite of algorithms dedicated to network nodes centrality analysis, computing several centralities for undirected, directed and weighted networks. The results of the topological analysis can be integrated with data set from lab experiments, like expression or phosphorylation levels for each protein represented in the network. Our app opens new perspectives in the analysis of biological networks, since the integration of topological analysis with lab experimental data enhance the predictive power of the bioinformatics analysis
Aproximating the Well-Founded Semantics for Normal Logic Programs using Abstract Interpretation
No full textCybersecurity impacts of the Covid-19 pandemic in Italy
No full textThe Covid-19 pandemic has pushed companies to the extensive use of digital services, to implement home working and provide online services to people in lockdown. As a consequence, it is interesting to study how this has affected the number, kind and distribution of cybersecurity attacks. This paper gives an empirical evaluation of the cybersecurity attacks at the beginning of the Covid-19 pandemic in Italy, based on data collected from the questionnaires of the annual Digital Attacks Observatory. It shows that the overall number of attacks has not increased, but attacks have affected smaller companies than before. This can be explained with the fact that the Italian industrial scenario is mostly populated by small and medium enterprises, that have been obliged to a quick reconversion of their IT systems and typically lack the necessary cybersecurity culture
Pair-Independence and Freeness Analysis through Linear Refinement
No full textLinear refinement is a technique for systematically constructing more precise abstract domains for program analysis starting from the basic domain which represents just the property of interest. We use here linear refinement to construct a domain for pair-independence and freeness analysis of logic programs which is strictly more precise than Jacobs and Langen's domain for sharing analysis endowed with freeness information. Moreover, it can be used for abstract compilation, while Jacobs and Langen's domain can only be used for abstract interpretation. We provide an approximate representation of our domain and algorithms for the abstract operations. We describe an implementation of an analyser which uses abstract compilation over our domain and its evaluation over a set of benchmarks. This shows that its precision is comparable to that of a traditional sharing and freeness analysis performed through abstract interpretation. To the best of our knowledge, this is the first implementation of a sharing analysis based on abstract compilation, as well as the first implementation of a static analysis based on a new domain developed through linear refinement
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
Static analysis for discovering IoT vulnerabilities
Full text linkThe Open Web Application Security Project (OWASP), released the “OWASP Top 10 Internet of Things 2018” list of the high-priority security vulnerabilities for IoT systems. The diversity of these vulnerabilities poses a great challenge toward development of a robust solution for their detection and mitigation. In this paper, we discuss the relationship between these vulnerabilities and the ones listed by OWASP Top 10 (focused on Web applications rather than IoT systems), how these vulnerabilities can actually be exploited, and in which cases static analysis can help in preventing them. Then, we present an extension of an industrial analyzer (Julia) that already covers five out of the top seven vulnerabilities of OWASP Top 10, and we discuss which IoT Top 10 vulnerabilities might be detected by the existing analyses or their extension. The experimental results present the application of some existing Julia’s analyses and their extension to IoT systems, showing its effectiveness of the analysis of some representative case studies
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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