Search results for "vision."

Wavelet analysis of human photoreceptoral response

2010

Feature detection of biomedical signals is crucial for deepening our knowledge of the physiological phenomena giving rise to them. To achieve this aim, even if many analytic approaches have been suggested only few are able to deal with signals whose features are time dependent, and to provide useful clinical information. In this work we use the wavelet analysis to extract peculiarities of the early response of the photoreceptoral human system, known as a-wave ERG-component. The analysis of the a-wave features is important since this component reflects the functional integrity of the two populations of photoreceptors, rods and cones whose activation dynamics are not well known. Moreover, in …

On utilizing dependence-based information to enhance micro-aggregation for secure statistical databases

2011

Published version of an article in the journal: Pattern Analysis and Applications. Also available from the publisher at: http://dx.doi.org/10.1007/s10044-011-0199-9 We consider the micro-aggregation problem which involves partitioning a set of individual records in a micro-data file into a number of mutually exclusive and exhaustive groups. This problem, which seeks for the best partition of the micro-data file, is known to be NP-hard, and has been tackled using many heuristic solutions. In this paper, we would like to demonstrate that in the process of developing micro-aggregation techniques (MATs), it is expedient to incorporate information about the dependence between the random variable…

A PARALLEL ALGORITHM FOR ANALYZING CONNECTED COMPONENTS IN BINARY IMAGES

1992

In this paper, a parallel algorithm for analyzing connected components in binary images is described. It is based on the extension of the Cylindrical Algebraic Decomposition (CAD) to a two-dimensional (2D) discrete space. This extension allows us to find the number of connected components, to determine their connectivity degree, and to solve the visibility problem. The parallel implementation of the algorithm is outlined and its time/space complexity is given.

Detection and classification of microcalcifications clusters in digitized mammograms

2005

In the present paper we discuss a new approach for the detection of microcalcification clusters, based on neural networks and developed as part of the MAGIC-5 project, an INFN-funded program which aims at the development and implementation of CAD algorithms in a GRID-based distributed environment. The proposed approach has as its roots the desire to maximize the rejection of background during the analytical pre-processing stage, in order to train and test the neural network with as clean as possible a sample and therefore maximize its performance. The algorithm is composed of three modules: the image pre-processing, the feature extraction component and the Backpropagation Neural Network mod…

Two-view “cylindrical decomposition” of binary images

2001

This paper describes the discrete cylindrical algebraic decomposition (DCAD) construction along two orthogonal views of binary images. The combination of two information is used to avoid ambiguities for image recognition purposes. This algorithm associates an object connectivity graph to each connected component, allowing a complete description of the structuring information. Moreover, an easy and compact representation of the scene is achieved by using strings in a five letter alphabet. Examples on complex digital images are also provided. © 2001 Elsevier Science Inc.

A system based on neural architectures for the reconstruction of 3-D shapes from images

1991

The connectionist approach to the recovery of 3-D shape information from 2-D images developed by the authors, is based on a system made up by two cascaded neural networks. The first network is an implementation of the BCS, an architecture which derives from a biological model of the low level visual processes developed by Grossberg and Mingolla: this architecture extracts a sort of brightness gradient map from the image. The second network is a backpropagation architecture that supplies an estimate of the geometric parameters of the objects in the scene under consideration, starting from the outputs of the BCS. A detailed description of the system and the experimental results obtained by si…

Tracking the Emergence of the Consonant Bias in Visual-Word Recognition: Evidence with Developing Readers

2014

Recent research with skilled adult readers has consistently revealed an advantage of consonants over vowels in visual-word recognition (i.e., the so-called "consonant bias"). Nevertheless, little is known about how early in development the consonant bias emerges. This work aims to address this issue by studying the relative contribution of consonants and vowels at the early stages of visual-word recognition in developing readers (2(nd) and 4(th) Grade children) and skilled adult readers (college students) using a masked priming lexical decision task. Target words starting either with a consonant or a vowel were preceded by a briefly presented masked prime (50 ms) that could be the same as t…

Entre la reforma y la revolución. La labor del Gobierno Provisional de la Segunda República Española (abril-octubre de 1931)

2014

La presente tesis doctoral se centra en analizar la actividad desarrollada por el Gobierno Provisional de la República Española desde su toma de posesión el día 14 de abril de 1931 hasta su primera crisis ministerial, acaecida en la madrugada del día 14 de octubre del mismo año. Tomando como fuentes documentales la prensa de la época y las publicaciones legislativas oficiales, se analiza el curso de los acontecimientos políticos más relevantes del periodo, comenzando por el propio proceso de transición política de la Monarquía a la República, con las primeras medidas de institucionalización jurídica del nuevo régimen, tales como la aprobación del Estatuto Jurídico de la República, los nombr…

Analisi del processo di consumo istantaneo di singole utenze residenziali con il modello di Poisson ad impulsi rettangolari

2008

Streaming: ventajas, desafíos y oportunidades de las radiotelevisiones para captar audiencias

2021

La investigación muestra el crecimiento del consumo de streaming en los últimos años y refleja su incremento exponencial a raíz de la pandemia por la Covid 19 en 2020. La base científica cita a los autores más relevantes en esta temática y está avalada por los estudios e informes de organismos oficiales y privados de relevancia internacional. Se estudia el origen del streaming, su evolución y futuro con la ayuda de las nuevas herramientas tecnológicas, como las appsque permiten a los periodistas y al público poder entrar en directo en un informativo. Ello suponenuevas oportunidades de negocio para las radiotelevisiones generalistas creadoras de contenido en España. La investigación muestra …