Herramientas didácticas para la formación agroforestal

Como resultado de los trabajos de investigación por más de diez años del grupo Plan de Investigación para el Fortalecimiento Integral de las Comunidades – PIFIL, en este libro se evidencias las lecciones aprendidas en el diseño y uso de herramientas didácticas para la formación de comunidades rurales, destacándose el material didáctico manual y digital agroforestal como innovadores en la implementación de las tecnologías de la información y la comunicación – TIC que facilitan los procesos de enseñanza aprendizaje para la aprehensión del conocimiento, consolidación del tejido social; fortalecimiento de la cohesión y congestión que coadyuvan con el mejoramiento de los medios de vida y uso sustentable de los recursos naturales

Nucleotomía Percutánea Automatizada: nuestra Experiencia

Ante las diferentes técnicas quirúrgicas en la patología del disco lumbar, los autores presentan su experiencia personal con la nucleotomía percutánea automatizada utilizando el nucleotomo de Surgical Dynamics. Sobre un total de 50 pacientes intervenidos se expone la técnica utilizada, con algunas variantes sobre la inicial de Onik, tal como la posición en sedestación del enfermo. Se puntualizan las indicaciones y contraindicaciones y se analizan los resultados obtenidos tras un mínimo de 6 meses de seguimiento. Se considera como una técnica útil, adecuada, relativamente inócua y que no sustituye sino que complementa a los procedimientos quirúrgicos convencionales.Faced with the different surgical techniques of lumbar disk pathology» the authors convery personal experience with automated percutaneous nucleotomy using the Surgical Dynamics. Based on the intervention of 50 patients, the technique used is explained, with some variations of the Onik procedure, such as the sitting position of the patient. The indications and contraindications are reviewed by the analysis. The results obtained with 6 months of follow up. The technique is considered usefull, proper, and relatively innocuous. It does not substitute but complements conventional surgical procedures

Periodic Chaotic Billiards: Quantum-Classical Correspondence in Energy Space

We investigate the properties of eigenstates and local density of states (LDOS) for a periodic 2D rippled billiard, focusing on their quantum-classical correspondence in energy representation. To construct the classical counterparts of LDOS and the structure of eigenstates (SES), the effects of the boundary are first incorporated (via a canonical transformation) into an effective potential, rendering the one-particle motion in the 2D rippled billiard equivalent to that of two-interacting particles in 1D geometry. We show that classical counterparts of SES and LDOS in the case of strong chaotic motion reveal quite a good correspondence with the quantum quantities. We also show that the main features of the SES and LDOS can be explained in terms of the underlying classical dynamics, in particular of certain periodic orbits. On the other hand, statistical properties of eigenstates and LDOS turn out to be different from those prescribed by random matrix theory. We discuss the quantum effects responsible for the non-ergodic character of the eigenstates and individual LDOS that seem to be generic for this type of billiards with a large number of transverse channels.Comment: 13 pages, 18 figure

Curriculum Learning for Cumulative Return Maximization

Curriculum learning has been successfully used in reinforcement learning to accelerate the learning process, through knowledge transfer between tasks of increasing complexity. Critical tasks, in which suboptimal exploratory actions must be minimized, can benefit from curriculum learning, and its ability to shape exploration through transfer. We propose a task sequencing algorithm maximizing the cumulative return, that is, the return obtained by the agent across all the learning episodes. By maximizing the cumulative return, the agent not only aims at achieving high rewards as fast as possible, but also at doing so while limiting suboptimal actions. We experimentally compare our task sequencing algorithm to several popular metaheuristic algorithms for combinatorial optimization, and show that it achieves significantly better performance on the problem of cumulative return maximization. Furthermore, we validate our algorithm on a critical task, optimizing a home controller for a micro energy grid

Propiedades de paneles geopoliméricos basados en ceniza volante y metacaolín bajo ensayos de resistencia al fuego

This paper presents the results of a study about the effect of fire on geopolymer paste composed of fly ashes, metakaolin and sodium silicate. 2 cm thick, 28 cm high and 18 cm wide panels were filled with the paste obtained. After 28 days of curing at 20 °C and 45% of relative humidity, different tests were carried out in the geopolymers: physico-chemical (density, water absorption, porosity), mechanical (flexural and compressive strength), fire resistance and environmental (leaching and radioactivity). The panels manufactured have been compared with other commercial panels in order to determine the recycling possibilities of fly ashes in manufacturing new fire-insulating geopolymers. The panels obtained can be utilized for the production of interior wall materials, with a good physical, mechanical, fire resistant properties without any environmental problem.Este documento presenta los resultados de un estudio sobre el efecto del fuego sobre pastas de geopolímeros compuestas de cenizas volantes, metacaolín y silicato sódico. Con la pasta obtenida se han rellenado paneles de dimensiones 2 cm de espesor, 28 cm de altura y 18 cm de ancho. Tras 28 días de curado a 20 °C y un 45% de humedad relativa, diferentes ensayos fueron realizados en los geopolímeros obtenidos: fisicoquímicos (densidad, absorción de agua, porosidad), mecánicos (resistencia a compresión y a flexión), de resistencia al fuego y medioambientales (lixiviación y radioactividad). Los paneles fabricados han sido comparados con paneles comerciales para determinar las posibilidades de reciclaje de las cenizas volantes para la fabricación de nuevos productos geopoliméricos con propiedades aislantes al fuego. Los paneles obtenidos pueden ser utilizados para la producción de paredes interiores, con buenas propiedades físicas, mecánicas y de resistencia al fuego sin ningún problema medioambiental

Chaotic Waveguide-Based Resonators for Microlasers

We propose the construction of highly directional emission microlasers using two-dimensional high-index semiconductor waveguides as {\it open} resonators. The prototype waveguide is formed by two collinear leads connected to a cavity of certain shape. The proposed lasing mechanism requires that the shape of the cavity yield mixed chaotic ray dynamics so as to have the appropiate (phase space) resonance islands. These islands allow, via Heisenberg's uncertainty principle, the appearance of quasi bound states (QBS) which, in turn, propitiate the lasing mechanism. The energy values of the QBS are found through the solution of the Helmholtz equation. We use classical ray dynamics to predict the direction and intensity of the lasing produced by such open resonators for typical values of the index of refraction.Comment: 5 pages, 5 figure

A combinatorial smoothness criterion for spherical varieties

We suggest a combinatorial criterion for the smoothness of an arbitrary spherical variety using the classification of multiplicity-free spaces, generalizing an earlier result of Camus for spherical varieties of type $A$.Comment: 14 pages, 2 table