1,721,422 research outputs found
Self-perception of competence and stereotyping of sport activities in infant development
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Privacy-Preserving Analysis for Remote Video Anomaly Detection in Real Life Environments
Full text linkThis paper proposes a novel approach for privacy-preserving surveillance video streams anomaly detection, i.e., situations implying violence, illegal actions, or situations involving hazards. In par-ticular, this approach adopts a privacy-preserving mechanism based on autoencoder neural networks applied in a differential private manner, exploiting three different types of differential private opti-mizers. Recorded real-world video streams are segmented into data frames, which are compressed into special codes with autoencoders and differential privacy and transmitted to a central server where they get decoded into an anonymized version of the original data frame that can be analyzed to detect anomalies. The anomaly detection algorithm exploits a supervised learning binary classification methodology of extracted contextual, spatial, and motion data on imbalanced datasets. Anomalies are differentiated into ”soft” and ”hard”, and the anomaly detection score is computed based on a sigmoidal function. The proposed methodology has been validated with a set of experiments on a well-known video anomaly dataset: UCF-CRIME. The experiments we conducted on the testbed demonstrate the capability of the system to correctly identify video anomalies, with a consistent privacy gain demonstrated by the strongly reduced ability to identify people from faces in the recon-structed frames
Using recurrent neural networks for continuous authentication through gait analysis
No full textThis letter presents a novel framework for continuous user authentication of mobile devices based on gait analysis, exploiting inertial sensors and Recurrent Neural Network for deep-learning based classification. The proposed framework handles all the continuous authentication stages, starting from data collection to data preprocessing, classification, and policy enforcement. The letter will emphasize the data analysis aspects, discussing the methodologies used to improve the quality of classification, including data augmentation and a sliding window interval approach for improved training. Furthermore, will be discussed the enforcement, which is based on the Usage Control paradigm for continuous policy enforcement. A set of real experiments will demonstrate the effectiveness and efficiency of the proposed framework
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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