1,720,986 research outputs found
Coherence of PRNU weighted estimations for improved source camera identification
Full text linkThis paper presents a method for Photo Response Non Uniformity (PRNU) pattern noise based camera identification. It takes advantage of the coherence between different PRNU estimations restricted to specific image regions. The main idea is based on the following observations: different methods can be used for estimating PRNU contribution in a given image; the estimation has not the same accuracy in the whole image as a more faithful estimation is expected from flat regions. Hence, two different estimations of the reference PRNU have been considered in the classification procedure, and the coherence of the similarity metric between them, when evaluated in three different image regions, is used as classification feature. More coherence is expected in case of matching, i.e. the image has been acquired by the analysed device, than in the opposite case, where similarity metric is almost noisy and then unpredictable. Presented results show that the proposed approach provides comparable and often better classification results of some state of the art methods, showing to be robust to lack of flat field (FF) images availability, devices of the same brand or model, uploading/downloading from social networks
Skeleton-based reassignment of nonstationary signals spectrogram
No full textMany practical applications require ridge curves detection and enhancement as they allow for instantaneous frequency estimation of nonstationary signals. Unfortunately, the reconstruction of those curves becomes a difficult task whenever multicomponent signals having non-separable modes have to be analyzed. To address this issue, this paper introduces a novel binary model for the spectrogram of multicomponent signals, and applies skeleton to enhance IF curves. To further improve the skeleton-based reassignment, a convolution-deconvolution scheme, that is directly derived from a specific evolution law for signal time-frequency (TF) distribution, is also defined. Experimental results show that the skeleton-based approach can reproduce IF curves of separable modes accurately. In addition, it allows to outperform classical amplitude-based reassignment method in the case of non separable modes
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
Il ruolo del Medico Competente nella prevenzione degli infortuni sul lavoro e nella tutela del lavoatore infortunato
No full textVariations 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
Research perspectives on corporate reputation and company’s performance measurement: an interpretive framework
No full textIn the knowledge economy, corporate reputation is relevant in increasing financial
and extra-financial performance of contemporary companies. Although corporate
reputation represents a significant dimension of relational capital, included in the
intellectual capital, its characteristics are not easy to measure in assessing company
performance over the time. In this direction, the paper aims to analyze the corporate reputation as influential intangible asset of contemporary company to define
its evaluation by completing the company performance measurement system. This
paper uses an updated conceptualization of corporate reputation literature which
focuses on the need to integrate and complete the value of company performance.
Performing a literature review on corporate reputation allows us to build an adequate framework for a new, integrated and innovative way to evaluate this intangible asset in the future scientific contribution. So, the research aims to create an integrated literature framework on corporate reputation, including studies on the
evaluation of corporate reputation as strategic asset, its relevance in the definition
of company performance, its impact on stakeholders’ behavio
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