1,720,956 research outputs found
A novel security information and event management system for enhancing cyber security in a hydroelectric dam
No full textSecurity information and event management (SIEM) systems are increasingly used to cope with the security challenges involved in critical infrastructure protection. However, these systems have several limitations. This paper describes an enhanced security information and event management system that (i) resolves conflicts between security policies; (ii) discovers unauthorized network data paths and appropriately reconfigures network devices; and (iii) provides an intrusion- and fault-tolerant storage system that ensures the integrity and non-forgeability of stored events. The performance of the enhanced system is demonstrated using a case study involving a hydroelectric dam. The case study considers an attack model that affects portions of the information technology infrastructure of the hydroelectric dam and demonstrates that the security information and event management system is successfully able to detect and respond to attack
An Intrusion and Fault Tolerant Forensic Storage for a SIEM System
No full textCurrent Security Information and Events Management (SIEM) solutions lack a data storage facility which is secure enough - i.e. stored events related to security incidents cannot be forged and are always available - that it can be used for forensic purposes. Forensic storage used by current SIEM solutions uses traditional RSA algorithm to sign the security events. In this paper we have analyzed the limits of current forensic storages, and we have proposed an architecture for forensic storage, implementing a threshold-based variant of the RSA algorithm, that outperforms state of the art SIEM solutions in terms of intrusion- and fault-tolerance. We show by experiments that our forensic storage works correctly even in the presence of cyber-attacks, although with a performance penalty. We also conduct an experimental campaign to evaluate the performance cost of the proposed scheme as a function of the threshold
A GPS Spoofing Resilient WAMS for Smart Grid
No full textSmart grids provide efficiency in energy distribution, easy identification of disturbance sources, and fault prediction. To achieve these benefits a continuous monitoring of voltage and current phasors must be performed. Phasor Measurement Units (PMUs) allow measurements of the phasors. A Wide Area Measurement System uses PMUs placed in different locations to assess the status of the power grid. To correctly analyze the phasors provided by PMUs, phasors must refer to the same time. For this reason each PMU uses the clock provided by a GPS receiver. GPS receiver is vulnerable to spoofing attack and it is a single point of failure. In this context we examined Network Time Protocol (NTP) as an alternative time source when the GPS receiver is compromised. In this paper a resilient architecture is proposed that is able to detect and react to the GPS spoofing attack. Experimental tests have shown the effectiveness of our solution
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
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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