1,721,067 research outputs found
Differential Morphing Attack Detection via Triplet-Based Metric Learning and Artifact Extraction
No full textOn the Impact of Face Image Quality on Morphing Attack Detection
Full text linkThe morphing attack is widely acknowledged as an important security threat to face recognition systems in the context of electronic machine readable travel documents and several possible countermeasures have been recently proposed. Among the existing solutions, differential Morphing Attack Detection (MAD) algorithms, based on the comparison of the document image (possibly morphed) and a trusted live capture, proved to be quite effective and robust in detecting this kind of attack. However, deploying such solutions in a real-world operational scenario requires the capability of dealing with images of variable quality in terms of illumination, pose, focus, etc. This paper analyzes the impact of face image quality on MAD performance through an extensive image quality assessment, carried out on a large and realistic operational dataset using different state-of-the-art algorithms, thus providing useful insights for the development of more robust MAD systems
Measurement of rotational magnetic properties of nanocrystalline alloys by a modified B-H sensor
No full textNanocrystalline alloys are now widely used in high frequency electromagnetic applications such as high frequency transformers and chokes, while it’s two-dimensional properties are seldom investigated. The nanocrystalline sample can be extremely brittle after annealed and crystallized which is very difficult to measure the properties by traditional method in 2D cases. The magnetic properties of nanocrystalline alloys under rotating field are measured and discussed in this paper. By combining the needle probe technique and the H-coil method, the magnetic flux density B and the magnetic field strength H in the sample can be measured. Finally, the modified B-H sensor is calibrated by the Helmholtz coils and the sensitivity of measuring B and H can achieve 4.3 mV/T and 30 μV/A/m respectively
A New Magnetizer for Measuring the Two-Dimensional Magnetic Properties of Nanocrystalline Alloys at High Frequencies
No full textNanocrystalline alloys are used extensively in high-frequency electromagnetic applications for their low magnetic losses and high saturation flux densities. To characterize their vector magnetic properties over a broad frequency range, a new magnetizer with a compact flux density-field B-H sensor was developed for two-dimensional testing up to 10 kHz
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
The application of XRF scanning to different geological archives
No full textFor this datasets we further our efforts using high resolution XRF scanning method on loess, stalagmite, and tridacna samples to illucidate which elements can be robustly obtained by XRF scanning, focusing on reproducibility, and the major factors (settings, scanning path, resolution) influencing the results for each three archives
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