1,721,188 research outputs found
Formal analysis of BPMN via a translation into COWS
No full textA translation of the Business Process Modeling Notation into the process calculus COWS is presented. The stochastic extension of COWS is then exploited to address quantitative reasoning about the behaviour of business processes. An example of such reasoning is shown by running the PRISM probabilistic model checker on a case study
Impact Analysis of Coordinated Cyber-Physical Attacks via Statistical Model Checking: A Case Study
No full textAn Approach to Trade-off Privacy and Classification Accuracy in Machine Learning Processes
No full textMachine learning techniques applied to large and distributed data archives might result in the disclosure of sensitive information. Data often contain sensitive identifiable information, and even if these are protected, the excessive processing capabilities of current machine learning techniques might facilitate the identification of individuals. This discussion paper presents a decision-support framework for data anonymization. The latter relies on a novel approach that exploits data correlations, expressed in terms of relaxed functional dependencies (rfds), to identify data anonymization strategies for providing suitable trade-offs between privacy and data utility. It also permits to generate anonymization strategies leveraging multiple data correlations simultaneously to increase the utility of anonymized datasets. In addition, our framework provides support in the selection of the anonymization strategies by enabling an understanding of the trade-offs between privacy and data utility offered by the obtained strategies. Experiments on real-life datasets show that our approach achieves promising results in data utility while guaranteeing the desired privacy level. Additionally, it allows data owners to select anonymization strategies balancing their privacy and data utility requirements
An enhanced CFA for security policies
No full textWe introduce a Control Flow Analysis, improving the one in [6], that statically approximates the dynamic behaviour of mobile processes, expressed in (a variant of) the -calculus. Our analysis of a system is able to describe the behaviour of each sub-system, tracking where and between whom communications may occur. To identify each sub-system, we use a syntactic encoding of its position inside the abstract syntax tree
Obfuscation strategies for industrial control systems
No full textRecently released scan data on Shodan reveals that thousands of Industrial Control Systems (ICSs) worldwide are directly accessible via the Internet and, thus, exposed to cyber-attacks aiming at financial gain, espionage, or disruption and/or sabotage. Executing sophisticated cyber-physical attacks aiming to manipulate industrial functionalities requires a deep understanding of the underlying physical process at the core of the target ICS, for instance, through unauthorized access to memory registers of Programmable Logic Controllers (PLCs). However, to date, countermeasures aiming at hindering the comprehension of physical processes remain largely unexplored. In this work, we investigate the use of obfuscation strategies to complicate process comprehension of ICSs while preserving their runtime evolution. To this end, we propose a framework to design and evaluate obfuscation strategies for PLCs, involving PLC memory registers, PLC code (user program), and the introduction of extra (spurious) physical processes. Our framework categorizes obfuscation strategies based on two dimensions: the type of (spurious) registers employed in the obfuscation strategy and the dependence on the (genuine) physical process. To evaluate the efficacy of proposed obfuscation strategies, we introduce evaluation metrics to assess their potency and resilience, in terms of system invariants the attacker can derive, and their cost in terms of computational overhead due to runtime modifications of spurious PLC registers. We developed a prototype tool to automatize the devised obfuscation strategies and applied them to a non-trivial use case in the field of water tank systems. Our results show that code obfuscation can be effectively used to counter malicious process comprehension of ICSs achieved via scanning of PLC memory registers. To our knowledge, this is the first work using obfuscation as a technique to protect ICSs from such threats. The efficacy of the proposed obfuscation strategies predominantly depends on the intrinsic complexity of the interplay introduced between genuine and spurious registers
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
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