OTA-based non-linear function approximations

The suitability of operational transconductance amplifiers (OTAs) as the main active element to obtain basic building blocks for the design of programmable nonlinear continuous-time networks is examined. The main purpose is to show that the OTA, as the active element in basic building blocks, can be efficiently used for nonlinear continuous-time function synthesis. Two efficient nonlinear function synthesis approaches are presented. The first approach is a rational approximation, and the second is a piecewise-linear approach. Test circuits have been integrated using a 3-μm p-well CMOS process. The flexibility of the designed and tested circuits is confirmed

Los juegos de mesa como medio para la comprensión de conceptos matemáticos en los estudiantes del grado 7° de la Institución Educativa Fundación Manuel Aya de Fusagasugá, Cundinamarca.

imágenesEn este trabajo de investigación se propuso evaluar la efectividad de la enseñanza de los números enteros por medio de juegos matemáticos. Para ello, se efectuó una secuencia didáctica conformada por 3 sesiones, en la que los estudiantes participaron en actividades lúdicas como juegos de mesa, juegos de rol y actividades de reflexión sobre los aprendizajes. Los resultados del estudio demostraron que los alumnos que participaron en la secuencia didáctica lograron comprender los conocimientos básicos de los números enteros, como lo es la suma, la resta, la multiplicación y la división. Además, desarrollaron sus habilidades de resolución de problemas relacionados con los números enteros. Estos resultados indican que la enseñanza de los números enteros por medio de juegos matemáticos es una estrategia efectiva para mejorar la comprensión de estos conceptos en los estudiantes.The purpose of this research was to evaluate the effectiveness of teaching integers through mathematical games. For this purpose, a didactic sequence consisting of 3 sessions was carried out, in which students participated in ludic activities such as board games, role-playing games and activities for reflection on learning. The results of the study showed that the students who participated in the didactic sequence were able to understand the basic knowledge of integers, such as addition, subtraction, multiplication and division. In addition, they developed their problem-solving skills related to integers. These results indicate that teaching integers through mathematical games is an effective strategy to improve students' understanding of these concepts

Composición enzimática del veneno de la raya (Potamotrygom schroederi)

The stingrays (family potamotrygonidae) are fish that inhabit the rivers of Colombia. No study has been conducted based on the problem of accidents and poisoning causing these animals. This work aims to contribute to the knowledge of the composition of the venom enzyme stripe Potamotrygom schroederi, proposing search 6 enzymes: protease, 5'-nucleotidase, acid and alkaline phosphatases, phospholipase A2 and hyaluronidase. The venom was isolated stripe Potamotrygom schroederi, obtained from Negro river (Meta). The stripes were captured and under anesthetic management harpoon was removed and then left alone, the barbs were stored in liquid nitrogen and then were lyophilized, which were scraped and weighed and homogenized content, then centrifuged at 10,000 rpm for 10 minutes at 4°C, obtaining by lysis of the cells, the poison. It worked as a positive control for testing the purified hyaluronidase, Bothrops asper venom in the region of Armero, obtained by milking the snakes kept in captivity at the Serpentarium of the National Institute of Health. The negative control for all tests was a target. The different enzymatic techniques were standardized and results determine the presence of 4 of the 6 enzymes originally proposed: proteases, 5-nucleotidase, alkaline phosphatase and hyaluronidase. Additionally, a profile accident took place in the Departmental Hospital Villavicencio, finding 20 cases, with the presence of symptoms such as tissue necrosis, edema and pain, triggering in amputation of the affected limb. The results indicate that the stripes are poisonous animals that have a direct bearing on human health, because their venom has an enzyme mixture that causes serious disturbances in various systems, with no effective treatment, why should be considered a public health problem by incorporating within the group of venomous animals of Colombia.Las rayas de agua dulce (familia potamotrygonidae), son peces que habitan los ríos de Colombia. Ningún estudio se ha realizado basado en la problemática de la accidentabilidad y el envenenamiento que ocasionan estos animales. Este trabajo pretende dar un aporte para el conocimiento de la composición enzimática del veneno de la raya Potamotrygom schroederi, proponiéndose la búsqueda de 6 enzimas: proteasas, 5´-nucleotidasa, fosfatasas ácida y alcalina, fosfolipasa A2 y hialuronidasa. El veneno fue aislado de la raya Potamotrygom schroederi, obtenida del río Negro (Meta). Las rayas fueron capturadas y bajo manejo anestésico se retiró el arpón y posteriormente dejadas en libertad, los arpones se almacenaron en nitrógeno líquido y posteriormente fueron liofilizados, los cuales fueron raspados y su contenido pesado y homogenizado, luego se centrifugaron a 10.000 revoluciones por 10 minutos a 4°C, obteniéndose por lisis de las células, el veneno. Se trabajó como control positivo de los ensayos la hialuronidasa purificada, el veneno de Bothrops asper de la región de Armero, obtenido por ordeño de las serpientes mantenidas en cautiverio en el serpentario del Instituto Nacional de Salud. El control negativo para todos los ensayos fue un blanco. Las diferentes técnicas enzimáticas fueron estandarizadas y los resultados obtenidos determinan la presencia de 4 de las 6 enzimas propuestas inicialmente: proteasas, 5-Nucleotidasa, fosfatasa alcalina y hialuronidasa. Adicionalmente se realizó un perfil de accidentalidad en el Hospital Departamental de Villavicencio, encontrándose 20 casos, con la presencia de síntomas tales como, necrosis tisular, edema y dolor, lo cual desencadenó en la amputación del miembro afectado. Los resultados obtenidos indican que las rayas son animales venenosos que influyen de manera directa en la salud humana, debido a que su veneno posee una mezcla enzimática que ocasiona disturbios graves en los diferentes sistemas, sin existir un tratamiento efectivo, razón por la cual deben ser considerados como un problema de salud pública, incorporándolos dentro del grupo de animales venenosos de Colombia

Sistema Inteligente de Tutoría para entrenamiento procedimental apoyado en un diálogo adaptado al contexto

El objetivo de este documento es presentar una propuesta de un Sistema Inteligente de Tutoría para entrenamiento procedimental en un entorno virtual 2D/3D, capaz de mantener un diálogo en lenguaje natural basado en el contexto. De esta manera, cada alumno será capacitado por medio de un diálogo en lenguaje natural que tome en cuenta sus características específicas, su progreso en el desarrollo de la tarea y el entorno donde se realiza la tarea. Por lo tanto, la retroalimentación de tutoría será el resultado de un diálogo adaptado al contexto. Para dar soporte al diálogo, se utilizará un gestor de diálogo, construido sobre alguna de las plataformas conocidas para la creación de gestores de diálogo actualmente disponibles

A model for student action prediction in 3D virtual environments for procedural training

This paper presents a predictive student actionmodel, which uses student logs generated by a 3D virtual environment for procedural training to elaborate summarized information. This model can predict the most common behaviors by con- sidering the sequences of more frequent actions, which is useful to anticipate common student? errors. These logs are clustered based on the number of errors made by each stu- dent and the total time that each student spent to complete the entire practice. Next, for each cluster an extended au- tomata is created, which allows us to generate predictions more reliable to each student type. In turn, the action pre- diction based on this model helps an intelligent tutoring sys- tem to generate students? feedback proactively

Born Digital Records of Mexican Indigenous People: A Proposal to Preserve Sound and Audiovisual Documents of Raramuri ́s Culture

Each day increases the amount of digital born sound and audiovisual documents as collections in libraries, archives and museums. However are unaware how these collections must be preserved for the future. Therefore, the risk of loss is increased. All types of sound and audiovisual recordings in risk if they are not documented and preserved properly, highlights the recordings of the indigenous peoples. This is serious phenomenon because with the loss of an indigenous language will be lost knowledge, worldview, and the way of understanding the world of a social group. The diversity of the indigenous languages of Mexico as cultural heritage and as information resource, is under threat. Indeed, it has been noted that when concluded this century half of 6 thousand languages spoken in the world be it extinguished (UNESCO, 2003). Of these the most vulnerable are those who speak are in indigenous communities. Of the various strategies that have been proposed to preserve indigenous languages, emphasizes the recording of music, rituals, stories, among others. For this reason, sound and audiovisual documents of the indigenous peoples are valuable resources of information. Recordings of indigenous peoples of Mexico have a high documentary value, precisely as endangered documents. Therefore, this paper will present the progress of the project Digital preservation of born digital audiovisual and sound collections developed by UNAM and the École européenne Supérieure de l\u27image, Poitiers France; and sponsored by the PAPIIT (Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica). This international project will focus on addressing one of the priority issues in libraries and archives: the preservation of sound and audiovisual collections digital born. This project responds to the global trend characterized by the search for solutions to ensure that the sounds and images that reflect our identity should be preserved in the future

An architecture for virtual labs in engineering education

This paper describes the preliminary results of an educational innovation project in which virtual world technologies have been used to build up a set of virtual laboratories oriented to engineering studies. Focusing on the architecture of a biotechnology laboratory created in this project, we describe how this architecture will also be adopted in other labs under construction, so that these labs can also take advantage of the same educational benefits. Instead of relying on a commercial software solution, these labs have been created with an open source software infrastructure named OpenSim. The limitations found in OpenSim and the solutions that have been provided to overcome these limitations are shown