Efficient spatial-domain implementation of a multiscale image representation based on Gabor functions

Contiene tablas y fórmulasGabor schemes of multiscale image representation are useful in many computer vision applications. However, the classic Gabor expansion is computationally expensive due to the lack of orthogonality of Gabor functions. Some alternative schemes, based on the application of a bank of Gabor filters, have important advantages such as computational efficiency and robustness, at the cost of redundancy and lack of completeness. In a previous work we proposed a quasicomplete Gabor transform, suitable for fast implementations in either space or frequency domains. Reconstruction was achieved by simply adding together the even Gabor channels. In this work, we develop an optimized spatial-domain implementation, using one-dimensional, 11-tap filter masks, that is faster and more flexible than Fourier implementations. The reconstruction method is improved by applying fixed and independent weights to the Gabor channels before adding them. Finally, we analyze and implement, in the spatial domain, two ways to incorporate a high-pass residual, which permits a visually complete representation of the image.Peer reviewe

Production of microbial transglutaminase on media made from sugar cane molasses and glycerol

Transglutaminase is an enzyme that catalyses an acyl transfer reaction between γ-carboxamide groups of glutaminyl residues and lysine residues in proteins. Due to this property, this enzyme is used for enhancing textural properties of protein-rich food. The transglutaminase used as food additive is obtained by microorganisms, mainly by Streptoverticillium ladakanum. On the other hand, sugar cane molasses is a viscous liquid rich in noncrystallized carbohydrates (saccharose, glucose and fructose). In this work, the feasibility of using sugar cane molasses as a carbon source for the production of microbial transglutaminase by Streptoverticillium ladakanum NRRL 3191 has been studied. Carbon sources including sugar cane molasses (60 g of total sugars per L), glycerol (60 g/L) and their mixture in a ratio of 1:1 (30 g/L of each) were evaluated. Time course of microbial growth, transglutaminase activity and carbon source consumption were determined every 24 h during 120 h of fermentations at three agitation speeds (200, 300 or 400 rpm). The results showed that with the increase in agitation speed, the biomass concentration increased up to 8.39 g/L in the medium containing sugar cane molasses alone or the mixture of molasses and glycerol. The highest transglutaminase activity was obtained at 400 rpm in the medium containing a mixture of molasses and glycerol, reaching 0.460 U/mL, while in the medium containing sugar cane molasses alone, the activity was 0.240 U/mL, and using glycerol alone it was 0.250 U/mL. These results show that sugar cane molasses is a suitable medium for transglutaminase production when it is combined with glycerolA grant from FOMIX CONACYT – Gobierno de Tamaulipas (Ref. 2004/1055) to author Portilla-Rivera is gratefully acknowledged. The authors are grateful to Ministerio de Educación y Ciencia (Spain) for the financial support of this work (Project: AGL2006-08250/ALI)S

ANÁLISIS DE LA SERIE TEMPORAL DE LA ESTACIÓN DE MONITOREO CONTINUO CUEC - REGME

En el  presente estudio se realiza un análisis exhaustivo de la serie temporal de la estación de monitoreo contínuo CUEC en el periodo 2008-2014. Para tal efecto se obtuvieron soluciones diarias de coordenadas con sus respectivas precisiones en cada una de sus componentes tanto horizontales como verticales, para posteriormente realizar un análisis riguroso de la serie mediante una descomposición aditiva determinando la estacionalidad o periodicidad, la tendencia y el tipo de ruido presente en la serie. Previo a la descomposición se realizó una limpieza o depuración de los datos mediante la detección y corrección de saltos en la serie y eliminación de valores atípicos. Para la determinación de la tendencia utilizamos una regresión lineal ponderada cuya solución se obtuvo mediante un ajuste mínimo cuadrático, en la determinación de la estacionalidad se realizó un análisis espectral de la serie en el dominio de las frecuencias, ya que esta es una medidad que sirve para representar los ciclos, y en cuanto a la  obtención del ruido se lo realizó mediante el estudio del espectro de potencia. Los resultados obtenidos muestran que la estación CUEC tiene una periodicidad anual (1.03 años) en todas sus componentes y un tipo de ruido gaussiano fraccionario con un índice espectral entre 0 y -1, considerando que estos valores no reflejan el verdadero tipo de ruido existente, debido principalmente a un alto porcentaje de datos perdidos

Habilidades de argumentación. Una propuesta para el planteamiento de posibles soluciones a los conflictos interpersonales

El presente artículo muestra los resultados de una investigación en torno a la influencia del desarrollo de habilidades argumentativas en el planteamiento de posibles soluciones a los conflictos interpersonales que se presentan en el entorno escolar. Se realizó un estudio cualitativo descriptivo, en el cual se diseñó una unidad didáctica desde la estrategia del análisis de dilemas morales, a partir de situaciones conflictivas presentadas en el aula —adaptados al modelo de desarrollo moral de Kohlberg—. El estudio permitió la comprensión del concepto de conflicto interpersonal y el uso de la argumentación para el planteamiento de posibles soluciones sustentadas en argumentos razonados y razonables. La investigación permitió concluir que el desarrollo de habilidades argumentativas les brinda a los estudiantes herramientas conceptuales y metodológicas para afrontar situaciones de conflicto interpersonal de forma constructiva, de manera que se planteen soluciones argumentadas

Lecciones y practicum de Derecho Constitucional

El presente proyecto de innovación docente persigue un doble objetivo: la actualización de los contenidos de Lecciones de Derecho Constitucional II y la reorganización y difusión de las prácticas de Derecho Constitucional II. Mientras que la primera finalidad ya ha sido satisfecha, la segunda se está desarrollando al tiempo en el que se imparten las lecciones por parte de los distintos profesores.Departamento de Derecho Constitucional, Procesal y Eclesiástico del Estad

Texture synthesis-by-analysis method based on a multiscale early-vision model

A new texture synthesis-by-analysis method, applying a visually based approach that has some important advantages over more traditional texture modeling and synthesis techniques is introduced. The basis of the method is to encode the textural information by sampling both the power spectrum and the histogram of homogeneously textured images. The spectrum is sampled in a log-polar grid using a pyramid Gabor scheme. The input image is split into a set of 16 Gabor channels (using four spatial frequency levels and four orientations), plus a lowpass residual (LPR). The energy and equivalent bandwidths of each channel, as well as the LPR power spectrum and the histogram, are measured and the latter two are compressed. The synthesis process consists of generating 16 Gabor filtered independent noise signals with spectral centers equal to those of the Gabor filters, whose energy and equivalent bandwidths are calculated to reproduce the measured values. These bandpass signals are mixed into a single image, whose LPR power spectrum and histogram are modified to match the original features. Despite the coarse sampling scheme used, very good results have been achieved with nonstructured textures as well as with some quasiperiodic textures. Besides being applicable to a wide range of textures, the method is robust (stable, fully automatic, linear, and with a fixed code length) and compact (it uses only 69 parameters). © 1996 Society of Photo-optical Instrumentation Engineers.Peer Reviewe

Automatic computation of the area irradiated by ultrashort laser pulses in Sb materials through texture segmentation of TEM images

We have developed a robust method for automatic image segmentation based on a local multiscale texture description. First, we apply a bank of Gabor filters to the input, producing a joint representation of the image in the spatial and spatial-frequency domains. Then we obtain local texture descriptors, by basically computing the modulus of the filters' complex output. These texture descriptors constitute the input of a standard clustering segmentation algorithm. In this paper we present results of automatic segmentation and area computation of transmission electron microscopy (TEM) micrographs from Sb materials, containing areas featuring different crystallization. The results are highly satisfactory with a mean error of about 4% in area estimation. Since this method does not include any ad hoc feature for this particular application, an equivalent performance could be expected from other similar applications with textured micrograph images. PACS: 07.05.Pj; 42.30.Sy. | We have developed a robust method for automatic image segmentation based on a local multiscale texture description. First, we apply a bank of Gabor filters to the input, producing a joint representation of the image in the spatial and spatial-frequency domains. Then we obtain local texture descriptors, by basically computing the modulus of the filters' complex output. These texture descriptors constitute the input of a standard clustering segmentation algorithm. In this paper we present results of automatic segmentation and area computation of transmission electron microscopy (TEM) micrographs from Sb materials, containing areas featuring different crystallization. The results are highly satisfactory with a mean error of about 4% in area estimation. Since this method does not include any ad hoc feature for this particular application, an equivalent performance could be expected from other similar applications with textured micrograph images. © 1996 Elsevier Science B.V.This research was supported by the CICYT (Spain) under grant TIC94-0849.Peer Reviewe

Textures synthesis-by-analysis based on a multiscale early-vision model

Contiene fórmulas, 2 tablas y 14 ilustracionesThis paper introduces a new texture synthesis-by-analysis method, applying a visual-based approach which has some important advantages over more traditional texture modeling and synthesis techniques. The basis of the method is to encode the textural information by sampling both the power spectrum and the histogram of homogeneously textured images. The spectrum is sampled in a log-polar grid by using a pyramid Gabor scheme. The input image is split into a set of 16 Gabor channels (using four spatial frequency levels and four orientations), plus a low-pass residual (LPR). The energy and equivalent bandwidths of each channel, as well as the LPR power spectrum and the histogram, are measured and the latter two are compressed. The synthesis process consists of generating 16 Gabor filtered independent noise signals with spectral centers equal to those of the Gabor filters, whose energy and equivalent bandwidths are calculated in order to reproduce the measured values. These band-pass signals are mixed into a single image, whose LPR power spectrum and histogram are modified to match the original features. Despite the coarse sampling scheme used, very good results have been achieved with non structured textures as well as with some quasi-periodic textures. Besides being applicable to a wide range of textures, the method is robust (stable, fully automatic, linear, and with a fixed code length) and compact (it uses only 69 parameters).Work supported by the CICYT (Spain) under grant TIC/94-0849

Habilidades de argumentación. Una propuesta para el planteamiento de posibles soluciones a los conflictos interpersonales

This article shows the results of an investigation about the influence of the development of argumentative abilities on the approach of possible solutions to the interpersonal conflicts that occur in the school environment. A descriptive qualitative study was carried out, in which a didactic unit was designed, including the analysis of moral dilemmas of conflictive situations presented in the classroom as a strategy–adapted to the Kohlberg model–to emerge the students’ speeches. A descriptive qualitative study was carried out, in which a didactic unit was designed following the strategy of moral dilemma analysis, based on conflictive situations presented in the classroom–adapted to Kohlberg’s moral development model. This study allowed understanding of the concept of interpersonal conflict and the use of argumentation to approach possible solutions based on reasoned and reasonable arguments. This research concluded that the development of argumentative abilities provides students with conceptual and methodological tools, in order to deal with situations of interpersonal conflict constructively in a way that argumentative solutions arise.O presente artigo mostra os resultados de uma investigação sobre a influência do desenvolvimento de habilidades argumentativas na abordagem de possíveis soluções aos conflitos interpessoais que são apresentados no ambiente escolar. Foi realizado um estudo qualitativo descritivo, no qual foi projetada uma unidade didática a partir da estratégia de análise de dilemas morais, baseada em situações conflitantes apresentadas na sala de aula — adaptada ao modelo de desenvolvimento moral de Kohlberg—. O estudo permitiu a compreensão do conceito de conflito interpessoal e o uso da argumentação para a apresentação de possíveis soluções baseadas em argumentos razoados e razoáveis. A pesquisa permitiu concluir que o desenvolvimento de habilidades argumentativas proporciona aos alunos ferramentas conceituais e metodológicas para lidar com situações de conflito interpessoal de forma construtiva, de maneira a que surjam soluções argumentadas.El presente artículo muestra los resultados de una investigación en torno a la influencia del desarrollo de habilidades argumentativas en el planteamiento de posibles soluciones a los conflictos interpersonales que se presentan en el entorno escolar. Se realizó un estudio cualitativo descriptivo, en el cual se diseñó una unidad didáctica desde la estrategia del análisis de dilemas morales, a partir de situaciones conflictivas presentadas en el aula —adaptados al modelo de desarrollo moral de Kohlberg—. El estudio permitió la comprensión del concepto de conflicto interpersonal y el uso de la argumentación para el planteamiento de posibles soluciones sustentadas en argumentos razonados y razonables. La investigación permitió concluir que el desarrollo de habilidades argumentativas les brinda a los estudiantes herramientas conceptuales y metodológicas para afrontar situaciones de conflicto interpersonal de forma constructiva, de manera que se planteen soluciones argumentadas

El conflicto interpersonal como oportunidad para aprender a convivir en la escuela

Este artículo expone los resultados de una investigación en el aula, la cual, centró su indagación en el abordaje de los conflictos interpersonales que presentan los estudiantes en el contexto escolar, con el propósito de que los actores reconozcan el conflicto como una oportunidad para aprender a convivir con los demás. Por ser una investigación de tipo cualitativa descriptiva, se desarrolló un estudio etnográfico a través de un diseño, aplicación y evaluación de una unidad didáctica, basada en el análisis de dilemas morales, cuyo esquema de actividades se enfocaron en el desarrollo de habilidades para la argumentación, con el fin de que los estudiantes realizaran planteamientos razonados como posibles soluciones a los conflictos presentados. Asimismo, se realizó un análisis e interpretación de la información a través del enfoque hermenéutico para comprender cómo una formación encaminada al desarrollo de habilidades para la argumentación —específicamente, el análisis, la síntesis y la reflexión— permite la reflexión constructiva sobre la naturaleza del conflicto interpersonal y brinda herramientas para el planteamiento de soluciones sustentadas en argumentos razonados y razonables