1,721,183 research outputs found
Distributed Inference of Channel Occupation Probabilities in Cognitive Networks via Message Passing
No full textCooperative Spectrum Sensing based on the Limiting Eigenvalue Ratio Distribution in Wishart Matrices
No full textRecent advances in random matrix theory have
spurred the adoption of eigenvalue-based detection techniques for
cooperative spectrum sensing in cognitive radio. These techniques
use the ratio between the largest and the smallest eigenvalues
of the received signal covariance matrix to infer the presence
or absence of the primary signal. The results derived so far
are based on asymptotical assumptions, due to the difficulties
in characterizing the exact eigenvalues ratio distribution. By
exploiting a recent result on the limiting distribution of the
smallest eigenvalue in complex Wishart matrices, in this paper we
derive an expression for the limiting eigenvalue ratio distribution,
which turns out to be much more accurate than the previous
approximations also in the non-asymptotical region. This result
is then applied to calculate the decision sensing threshold as
a function of a target probability of false alarm. Numerical
simulations show that the proposed detection rule provides a
substantial improvement compared to the other eigenvalue-based
algorithms
Automatic detection of dangerous events for underground surveillance
No full textThis paper describes automatic video sequences processing techniques for detecting suspect and dangerous situations within public transportations. Proposed surveillance system is able to raise different kind of warnings and alarms on the basis of the particular detected situation. Algorithms used for objects detection and tracking will be described in details and performances will be discussed in relation with alarm conditions that are showed in the sequences that have been made available for this conference. An empty reference image is used for object extraction through image difference. In order to perform background updating a high level module is implemented taking into account the detected objects and their classification tags. The system has been tested on several sequences showing dangerous events due to human behaviors in a underground station
Asymmetric liposomes and uses in medical field thereof
No full textThe invention concerns new asymmetric liposomes and uses thereof in medicalfield transport lipids involved in antimicrobial or antiviral response, particularly at level of pulmonary target cells
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
Label-free metabolic clustering through unsupervised pixel classification of multiparametric fluorescent images
No full textAutofluorescence microscopy is a promising label-free approach to characterize NADH and FAD metabolites in live cells, with potential applications in clinical practice. Although spectrally resolved lifetime imaging techniques can acquire multiparametric information about the biophysical and biochemical state of the metabolites, these data are evaluated at the whole-cell level, thus providing only limited insights in the activation of metabolic networks at the microscale. To overcome this issue, here we introduce an artificial intelligence-based analysis that, leveraging the multiparametric content of spectrally resolved lifetime images, allows to detect and classify, through an unsupervised learning approach, metabolic clusters, which are regions having almost uniform metabolic properties. This method contextually detects the cellular mitochondrial turnover and the metabolic activation state of intracellular compartments at the pixel level, described by two functions: the cytosolic activation state (CAF) and the mitochondrial activation state (MAF). This method was applied to investigate metabolic changes elicited in the breast cancer cell line MCF-7 by specific inhibitors of glycolysis and electron transport chain, and by the deregulation of a specific mitochondrial enzyme (ACO2) leading to defective aerobic metabolism associated with tumor growth. In this model, mitochondrial fraction undergoes to a 13% increase upon ACO2 overexpression and the MAF function changes abruptly by altering the metabolic state of about the 25% of the mitochondrial pixels
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