1,721,018 research outputs found
Low cost routing in mobile ad-hoc networks: Is it achievable?
No full textCache schemes that adopt timeout (i.e. lifetime) for removing stale information have its correct estimation as basic assumption. An incorrect value for the timeout highly reduces the effect of the cache scheme or, even worst, produces a severe performance degradation rather than an improvement. However, lifetime estimation in mobile ad-hoc networks is difficult to assure due to the rapid ad random changes in the network topology as well as to dependency on the path length. In this paper we discuss the general issue of caching in the context of mobile environments as a means to achieve efficient routing protocols. We propose a class of cache schemes that adopt active topology monitoring to determine when cached routes become stale. The scheme requires explicit support from the routing protocol. We present an implementation of the scheme when using a ZRP-like routing protocol and present some preliminary performance results
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
Assisting Malware Analysis with Symbolic Execution: a Case Study
No full textSecurity analysts spend days or even weeks in trying to understand the inner workings of malicious software, using a plethora of manually orchestrated tools. Devising automated tools and techniques to assist and speed up the analysis process remains a major endeavor in computer security. While manual intervention will likely remain a key ingredient in the short and mid term, the recent advances in static and dynamic analysis techniques have the potential to significantly impact the malware analysis practice. In this paper we show how an analyst cause symbolic execution techniques to unveil critical behavior of a remote access trojan (RAT). Using a tool we implemented in the Angr framework, we analyze a sample drawn from a well-known RAT family that leverages thread injection vulnerabilities in the Microsoft Win32 API. Our case study shows how to automatically derive the list of commands supported by the RAT and the sequence of system calls that are activated for each of them, systematically exploring the stealthy communication protocol with the server and yielding clues to potential threats that may pass unnoticed by a manual inspection
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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