Diversity in mobile communications for blind detection of block-coded modulations

Spatial, temporal, and frequency diversity structures are analyzed to address the blind equalization problem in the presence of time-variant frequency selective channels. The aim of the paper is to present equalization schemes useful in front of fast changing channel responses. The best solution is a deterministic blind criterion that allows direct channel equalization and symbol detection. The main contribution of this paper is to present deterministic blind equalization schemes in CDMA systems (frequency diversity) to reduce the impact of the time-variant frequency selective channel.Peer ReviewedPostprint (published version

A new thin layer model for viscous flow between two nearby non-static surfaces

We propose a two-dimensional flow model of a viscous fluid between two close moving surfaces. We show, using a formal asymptotic expansion of the solution, that its asymptotic behavior, when the distance between the two surfaces tends to zero, is the same as that of the the Navier-Stokes equations. The leading term of the formal asymptotic expansions of the solutions to the new model and Navier-Stokes equations are solution of the same limit problem, and the type of the limit problem depends on the boundary conditions. If slip velocity boundary conditions are imposed on the upper and lower bound surfaces, the limit is a solution of a lubrication model, but if the tractions and friction forces are known on both bound surfaces, the limit is a solution of a thin fluid layer model. The model proposed has been obtained to be a valuable tool for computing viscous fluid flow between two nearby moving surfaces, without the need to decide a priori whether the flow is typical of a lubrication or a thin fluid layer problem, and without the enormous computational effort that would be required to solve the Navier-Stokes equations in such a thin domain.Comment: arXiv admin note: substantial text overlap with arXiv:2203.0869

Assessing social engagement practices in unstable environments: An examination of collective action and community participation in Mexico

El estudio que se presenta utiliza la teoría de Capital Social, explora los efectos del capital social, la violencia, y el compromiso político en dos observables: acción colectiva y voluntad de ayuda a la comunidad en México. Se utiliza una encuesta recabada en 2011 (N=7,416) y procedimientos estadísticos (correlaciones y análisis de regresión usando mínimos cuadrados ordinarios (MCO) con modelos anidados). Los resultados muestran que los factores contextuales y políticos, particularmente el miedo y la violencia, influyen en la mobillización en acción colectiva. Se indican algunas implicaciones para las interacciones sociales en escenarios de conflicto prolongado e inestabilidad, en particular, para México

Concurrent focal-plane generation of compressed samples fromtime-encoded pixel values

Compressive sampling allows wrapping the relevant content of an image in a reduced set of data. It exploits the sparsity of natural images. This principle can be employed to deliver images over a network under a restricted data rate and still receive enough meaningful information. An efficient implementation of this principle lies in the generation of the compressed samples right at the imager. Otherwise, i. e. digitizing the complete image and then composing the compressed samples in the digital plane, the required memory and processing resources can seriously compromise the budget of an autonomous camera node. In this paper we present the design of a pixel architecture that encodes light intensity into time, followed by a global strategy to pseudo-randomly combine pixel values and generate, on-chip and on-line, the compressed samples.Ministerio de Economía y Competitividad TEC 2015-66878-C3-1-RJunta de Andalucía TIC 2338-2013Office of Naval Research (USA) N000141410355CONACYT (Mexico) MZO-2017-29106

Education transformation in learning communities

Con la descripción de esta experiencia hemos pretendido dar a conocer qué es una Comunidad de Aprendizaje y analizar cómo funciona la del CEIP Andalucía de Sevilla, además de promover la reflexión de prácticas educativas favorecedoras del éxito escolar y la participación de la comunidad. La puesta en marcha de Comunidades de Aprendizaje precisa la implicación de múltiples agentes educativos, procesos de cambio, la introducción de nuevos modelos organizativos en el centro, el desarrollo de nuevas metodologías en el aula, el cambio de concepción de lo qué es un centro público, etc…Analizamos el ámbito de acción metodológico con la propuesta de grupos interactivos de aprendizaje y metodología de trabajo por proyectos; el ámbito curricular con sugerencias para las áreas de Lengua y Educación Artística y el ámbito de participación con la formación de las familias. Esta Comunidad de Aprendizaje ha incrementado los niveles de competencia curricular del alumnado y ha disminuido el absentismo escolar, dos aspectos claves en un contexto de marginación y exclusión social, además del trabajo colectivo y cooperativo de todo el claustro, voluntarios, asociaciones, instituciones y familias

Validation of microsatellite markers for cytotype discrimination in the model grass Brachypodium distachyon

Brachypodium distachyon (2n = 2x = 10) is a small annual grass species where the existence of three different cytotypes (10, 20 and 30 chromosomes) has long been regarded as a case of autopolyploid series, with x = 5. However, it has been demonstrated that the cytotypes assumed to be polyploids represent two separate Brachypodium species recently named as B. stacei (2n = 2x = 20) and B. hybridum (2n = 4x = 30). The aim of this study was to find a PCR-based alternative approach that could replace standard cytotyping methods (i. e., chromosome counting and flow cytometry) to characterize each of the three Brachypodium species. We have analyzed with four microsatellite (SSR) markers eighty-three Brachypodium distachyon-type lines from varied locations in Spain, including the Balearic and Canary Islands. Within this set of lines, 64, 4 and 15 had 10, 20 and 30 chromosomes, respectively. The surveyed markers produced cytotype-specific SSR profiles. So, a single amplification product was generated in the diploid samples, with non-overlapping allelic ranges between the 2n = 10 and 2n = 20 cytotypes, whereas two bands, one in the size range of each of the diploid cytotypes, were amplified in the 2n = 30 lines. Furthermore, the remarkable size difference obtained with the SSR ALB165 allowed the identification of the Brachypodium species by simple agarose gel electrophoresis

A prototype node for wireless vision sensor network applications development

This paper presents a prototype vision-enabled sensor node based on a commercial vision system of reduced size and power consumption. The wireless infrastructure for the deployment of a distributed smart camera network based on these nodes is provided by commercial motes. The smart camera, based on a low-power bio-inspired processing scheme, enables in-node image processing and vision tools. This permits to elaborate a lighter representation of the scene, keeping the relevant information in terms of detected elements, features and events, alleviating the data transmission through the network. Therefore by passing only the relevant information to the neighboring sensor nodes, distributed and collaborative vision is possible with the limited data rates available in commercial wireless sensor networks. Communication between the different components of the system is supported by the available UARTs and GPIOs. Several examples of in-node image processing and feature detection has been tested in the prototype, and information at different abstraction levels has been broadcasted to the network.Junta de Andalucía 2006-TIC-2352Ministerio de Ciencia e Innovación TEC2009-1181

Superficial Surface Treatment using Atmospheric Plasma on Recycled Nylon 6,6

Polymers currently represent materials that are cost-effective, while its recycled nature is significant in terms of environmental protection. However, the surface properties of polymers often do not meet the demands of wettability, adhesion, and friction, among others. Atmospheric plasma treatment on the surface of polymers improves its physical-chemistry properties. In this work, a recycled nylon coating was prepared by the spin coating technique and characterized by Fourier transform infrared spectroscopy and X-ray diffraction. This coating was treated by atmospheric plasma, and Raman spectroscopy was performed to analyze the signals related to different functional groups present in the coating surface after plasma treatment. The action of plasma on the surface morphology was observed by scanning electron microscopy. The contact angle results showed an improvement in surface wettability