1,721,022 research outputs found
A novel entropy method for classification of biosignals
No full textIn this paper a linear transformation, the spiral method, is introduced; this transformation maps an image represented in a 3-D space into a signal in a 2-D space. Some features of the spiral are presented: for instance the topologic information of the objects in the image, their contours, areas and the shape of the objects themselves. Two different case-study are presented: the use of spiral method in order to evaluate the number, the size, the shape and the location of the micorcalcifications by the use of signals related to the mammograms; entropy is proposed as a measure of the degree of the parenchyma disorder of the mammograms and its use for a system CAD
The Role Of Entrophy In Signal Analysis And Classification:An Application To Breast Diagnosis
No full textQuantum Monte Carlo study of a resonant Bose-Fermi mixture
Get PDFWe study resonant Bose-Fermi mixtures at zero temperature, with different relative concentrations
of the bosons. We use for the first time a Quantum Monte Carlo method with Fixed-Node approxima-
tion, to explore the system from the weak to the strong coupling limit. A repulsive interaction among
bosons is introduced to provide stability to the bosonic component. Beyond the unitarity limit, the res-
onant attractive interaction supports a bound fermionic dimer. At the many-body level, increasing the
boson-fermion coupling the system undergoes a quantum phase transition from a state with condensed bosons immersed in a Fermi sea, to a normal Fermi-Fermi mixture of the composite fermions and the bare fermions in excess. We obtain the equation of state and we characterize the momentum distributions both in the weakly and in the strongly interacting limits. We compare Quantum Monte Carlo results to T-matrix calculations, finding interesting signatures of the different many-body ground states
Content Image Retrieval Based On Topological Information
No full textIn this paper a novel scheme for representing topological features extracted from image database is proposed. The scheme utilizes a geometry-based structure that represents each image by means a string containing information on a polygonal associated with the pictorial scene. The presented retrieval method reveals to have good approach if compared with other existing methods and may be extended to include also texture and shape information of the objects belonging to the image
Quantum well excitons in semiconductor microcavities: Unified treatment of weak and strong coupling regimes
No full textThe Spiral Method applied to the Study of the Microcalcifications in Mammograms
No full textIn this paper a linear transformation, the spiral method, is introduced; this transformation maps an image represented in a 3-D space into a signal in a 2-D space. Some features of the spiral are presented: for instance the topologic information of the objects in the image, their contours, areas and the shape of the objects themselves, Two different case-study are presented: the use of spiral method in order to evaluate the number, the size, the shape and the location of the microcalcifications by the use of signals related to the mammograms; entropy is proposed as a measure of the degree of the parenchyma disorder of the mammograms and its use for a system CAD. © Springer-Verlag Berlin Heidelberg 2005
Optimal antibunching in passive photonic devices based on coupled nonlinear resonators
Get PDFWe propose the use of weakly nonlinear passive materials for prospective applications in integrated quantum photonics. It is shown that strong enhancement of native optical nonlinearities by electromagnetic field confinement in photonic crystal resonators can lead to single-photon generation only exploiting the quantum interference of two coupled modes and the effect of photon blockade under resonant coherent driving. For realistic system parameters in state of the art microcavities, the efficiency of such a single-photon source is theoretically characterized by means of the second-order correlation function at zero-time delay as the main figure of merit, where major sources of loss and decoherence are taken into account within a standard master equation treatment. These results could stimulate the realization of integrated quantum photonic devices based on non-resonant material media, fully integrable with current semiconductor technology and matching the relevant telecom band operational wavelengths, as an alternative to single-photon nonlinear devices based on cavity quantum electrodynamics with artificial atoms or single atomic-like emitters.LTP
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
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
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