1,721,007 research outputs found
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
Preliminary Design of aero-engine intake acoustic liners by means of the multi-objective approach
No full textCNN-AutoMIC: Combining convolutional neural network and autoencoder to learn non-linear features for KNN-based malware image classification
No full textMalware refers to malicious software or a component of software intended for malicious purposes. The manual analysis and detection of malicious software is challenging due to its complexity. Thus, several automated solutions have become popular for real-time malware detection. A spread-out approach consists of generating images from the samples bytecode and giving them to convolutional neural networks (CNNs), which are used either as classifiers or feature extractors for further classification algorithms. These systems perform extremely well when trained and tested on partitions of the same dataset. However, cross-dataset tests and malware detection verification on emerging real-world samples are required in the real-world context. This is a crucial challenge when probing the robustness of the systems and models. This paper proposes CNN-AutoMIC,a robust automated approach to extract features from malware images. CNN-AutoMIC employs a specific CNN architecture to extract features, followed by an autoencoder-based compressor that reduces features to two fundamental components. The two-dimensional projection of these components is the basis of the predictions performed by the K-nearest neighbors (K-NN) algorithm. Moreover, the observable placement of new samples on the obtained scatter plot makes it possible to explain why the AI-based system produced a certain prediction. It was benchmarked against several CNN-based models and a Vision Transformer. They were trained on the Malevis dataset and cross-dataset evaluated on four different real-world datasets. CNN-AutoMIC outperformed the competitors for each classification performance metric, while requiring a reasonable training and prediction time. In addition, it achieves a promising Akaike information criterion (AIC) score, indicating its efficiency in terms of model complexity
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
An innovative two-stage algorithm to optimize Firewall rule ordering
Get PDFPacket classification activity performed by a FireWall (FW) introduces high latency in network communications due to the computation time required to check whether any packet matches one of the FW rules. Such a classification process is done by sequentially checking the list of rules until a match is found or the end of the list is reached. Given the complexity of FW rules in some environments, this latency could become relevant. This problem is addressed by ordering the list of FW rules to minimize the classification latency, where the rules with higher activation frequencies are placed accordingly starting from the top of the list. This is not always feasible because dependency constraints between rules could exist: swapping the positions of dependent rules results in a loss of the integrity of the implemented security policy. For this reason, the FW rule ordering problem belongs to the realm of constrained combinatorial optimization. This paper proposes a two-stage algorithm to address this problem. The first stage performs an innovative topological sorting algorithm aimed at finding an optimal ordering for the constrained rules, taking into account the fact that rule activation frequencies are influenced by inter-packet arrival time, which typically obeys Zipf's law. The second stage employs a genetic algorithm to find the optimal ordering of all rules within the list. The proposed approach is evaluated using different filtering lists of different complexity provided by ClassBench. A comparison with other state-of-the-art algorithms addressing the same problem is performed. Furthermore, the performance analysis is extended employing an exact optimization method. The results obtained show the effectiveness of the proposed algorithm in minimizing packet classification latency, while a short reordering time is required
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
PROGESI: A PROxy Grammar to Enhance Web Application Firewall for SQL Injection Prevention
No full textA web application is prone to security threats due to its open nature. The security of these platforms is imperative for organizations of all sizes because they store sensitive information. Consequently, exploiting web application vulnerabilities could result in large-scale data breaches and significant brand and financial damages. SQL injection (SQLi) represents a popular attack vector that malicious actors use to compromise website security. Web application firewalls (WAFs) play a primary role in preventing such malicious attack typologies. In the recent literature, several advances have been proposed in the field of WAF enhancement to prevent SQLi exploitation. However, many of them test the effectiveness of a WAF without releasing a patch to fix security flaws if a WAF is bypassed. In other cases, the patch is distributed exclusively according to the syntax specified by the WAF tested. This paper introduces a framework that leverages PROxy Grammar to Enhance web application firewalls for SQL Injection prevention (PROGESI). The proposed solution can act as an intermediary layer between the targeted web server and the incoming application level requests. Specifically, PROGESI can be used individually or in combination with a WAF and includes a series of rules that patch SQLi vulnerabilities exposed by a specific web server. Furthermore, it can identify and mitigate SQLi attempts, also when attackers use mutation techniques, since the rules used encompass generalization mechanisms. The experiments performed revealed two strengths of PROGESI: (i) the ability to identify SQLi even in the presence of server-side defense mechanisms, which increases as the generalization rate implemented by the rule generation algorithm increases; (ii) impressive detection performance even for low generalization rate values, which is higher than that achieved by competitors using a state-of-the-art SQLi dataset
Automatic decision tree-based NIDPS ruleset generation for DoS/DDoS attacks
Get PDFAs the occurrence of Denial of Service and Distributed Denial of Service (DoS/DDoS) attacks increases, the demand for effective defense mechanisms increases. Recognition of such anomalies in the computer network is commonly performed through network-based intrusion detection and prevention systems (NIDPSs). Although NIDPSs allow the interception of all known attacks, they are not robust to the continuing variation over time of DoS/DDoS anomalies. The machine learning (ML) paradigm provides algorithms that can effectively reduce concept drift due to the evolution of cyber threat data patterns. These methodologies can be exploited for creating effective rules suitable for popular NIDPS engines such as Suricata.
This paper proposes a new algorithm called Anomaly2Sign, which automatically produces rules for Suricata through an automatic Decision Tree (DT)-based generation process. The DT is trained on both anomalous and legitimate traffic, allowing the generation process to select anomaly features that can be mapped within the generated rule structure. Additionally, the DT hyperparameters are tuned at execution time to generate a minimal ruleset capable of detecting the largest number of anomalous packets. The proposed algorithm achieves classification metrics in the range of 99.7%–99.9% using the BOUN-DoS and BUET-DDoS datasets, outperforming the compared ML classifiers, i.e., Logistic Regression, Support Vector Machine, and Multi-Layer Perceptron. Furthermore, the leveraged DT model requires a shorter training and prediction time than the previously cited benchmark classifiers. To enforce the selection of the DT model, an analysis of model complexity is undertaken, including the evaluation of the Akaike Information Criterion (AIC) score. As a result of such an evaluation, the DT model achieved the lowest AIC score among the compared approaches denoting its low complexity. Finally, Anomaly2Sign has been compared with Syrius, i.e., an alternative state-of-the-art automatic NIDPS rules generator, obtaining better performance for detection rate and execution time
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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