Further properties of the Bergman spaces of slice regular functions

In this paper we continue the study of Bergman theory for the class of slice regular functions. In the slice regular setting there are two possibilities to introduce the Bergman spaces, that are called of the first and of the second kind. In this paper we mainly consider the Bergman theory of the second kind, by providing an explicit description of the Bergman kernel in the case of the unit ball and of the half space. In the case of the unit ball, we study the Bergman-Sce transform. We also show that the two Bergman theories can be compared only if suitable weights are taken into account. Finally, we use the Schwarz reflection principle to relate the Bergman kernel with its values on a complex half plane.Comment: to appear in Advances in Geometr

Desarrollo Municipal, Una visión contemporanea

El desarrollo político de los países occidentales ha tenido un efecto decisivo en las transformaciones estructurales de las sociedades en proceso de modernización. La modificación de las economías tradicionales por la noción de economías de mercado o la estabilidad política por un escenario de dinamismo político, son un claro ejemplo

Guitar Chords Classification Using Uncertainty Measurements of Frequency Bins

This paper presents a method to perform chord classification from recorded audio. The signal harmonics are obtained by using the Fast Fourier Transform, and timbral information is suppressed by spectral whitening. A multiple fundamental frequency estimation of whitened data is achieved by adding attenuated harmonics by a weighting function. This paper proposes a method that performs feature selection by using a thresholding of the uncertainty of all frequency bins. Those measurements under the threshold are removed from the signal in the frequency domain. This allows a reduction of 95.53% of the signal characteristics, and the other 4.47% of frequency bins are used as enhanced information for the classifier. An Artificial Neural Network was utilized to classify four types of chords: major, minor, major 7th, and minor 7th. Those, played in the twelve musical notes, give a total of 48 different chords. Two reference methods (based on Hidden Markov Models) were compared with the method proposed in this paper by having the same database for the evaluation test. In most of the performed tests, the proposed method achieved a reasonably high performance, with an accuracy of 93%

Using Factorial Design Methodology to Assess PLA-g-Ma and Henequen Microfibrillated Cellulose Content on the Mechanical Properties of Poly(lactic acid) Composites

In this work, a 22 factorial design was used to study the effect of microfibrillated henequen cellulose fibers (HENCEL) and PLA-g-MA coupling agent contents on the tensile, flexural, and impact mechanical properties and the heat deflection temperature (HDT) of biodegradable PLA composites. The results show that the principal effects of HENCEL and MA are statistically significant for the tensile, flexural, HDT, and impact strength properties of PLA composites. Regarding the interactions between the principle effects, MA-HENCEL, there are differences with respect to the mechanical property; for example, for tensile and flexural mechanical properties, there is a synergistic effect between MA and HENCEL, whereas for HDT and impact strength there is not any. The micromechanical analysis shows an excellent agreement between the measured and the estimated values for both the composite tensile strength and the elastic modulus and only slight deviations were noticed for high microfibrillated cellulose fibers content. The morphological analysis via SEM indicated that the addition of PLA-g-MA improved the fiber-matrix adhesion because of the HENCEL unbounding and pull-out decreases from the PLA matrix. The use of appropriate values of matrix strength and stiffness and considering the improved fiber-matrix adhesion of the coupling agent yield a good agreement between experimental and estimated values

Estructura factorial y consistencia interna del Cuestionario para medir bullying y violencia escolar

La violencia escolar, que incluye al bullying o acoso escolar entre iguales, es un problema que involucra a muchos jóvenes, ya sea como víctimas, acosadores u observadores. Por ello, la detección del rol del participante es importante para contrarrestarlo. El objetivo de este estudio fue desarrollar y validar un instrumento que permita evaluar el bullying y la violencia en general en escuelas secundarias de México, a partir del Cuestionario de evaluación de la violencia entre iguales en la escuela y en el ocio. Para ello, se seleccionó una muestra de 363 adolescentes entre 12 años y 17 años de edad, de 10 escuelas secundarias públicas de los estados de Aguascalientes y Distrito Federal. El diseño de la investigación fue de tipo transversal. El total de reactivos valorados fueron 57 y la escala para valorar las respuestas fue de tipo Likert con cuatro opciones. Los reactivos fueron organizados en tres escalas (recibir, dirigir u observar agresión), con 19 reactivos cada uno y construidos en espejo. Para cada escala se aplicó un análisis factorial Promax, que permite identificar el tipo de agresión empleada y el rol que desempeña el alumnado como víctima, acosador o espectador. Los resultados confirmaron que el cuestionario es un instrumento que permite medir acoso escolar en adolescentes, con un índice de confiabilidad general de 0.90. Por lo que se concluye que este instrumento es adecuado para identificar acoso escolar en población mexicana

Socio-Ecological Regionalization of the Urban Sub-Basins in Mexic

Mexico is a diverse country in terms of culture and natural environments. For this reason, the delimitation of homogeneous basins with similar environmental, social, and economic attributes is important in order to facilitate the elaboration of high-impact regional development strategies. However, this represents an ongoing challenge due to the complexity of the interactions that occur within socio-ecological systems at a regional scale. In the present study, the main objective was to identify the interrelationships among different aspects of the socio-ecological system located within basins, with the goal of utilizing this information to promote the region-specific sustainable development of an Integrated Water Resources Management (IWRM). Therefore, in this study, environmental, social, economic, and institutional variables, relevant to water management and with thecapacitytobeexpressedspatially,wereutilizedtoidentifyregionswithsimilarcharacteristicsand to regionalize the urban sub-basins of Mexico based on a principal component analysis (PCA) and the k-medoids clustering algorithm. The identification of the most adequate number of regions at the national level was determined by the silhouette method. As a result, five distinct regions for Mexico were generated, which forms the first step in the design of integrated water resources management strategies for these regions.Universidad Autónoma del Estado de MéxicoConsejo Nacional de Ciencia y Tecnología (CONACyT-México