Compresión de Audio Basada en Codificación Subbanda

An eight channels subband audio codec is implemented for signals with 44.1 KHz and 16 bits per sample using Matlab. To achieve perfect reconstruction, a two channels QMF filter bank with cutoff frequency ω=π/2 is designed, based on an equiriple filter of 99 order. Seven stages of this bank are used to split the input into eight signals with sample rates from 2.76 to 11 KHz, which are coded from 1 to 16 bits depending on the band energy. To evaluate performance for three tracks in terms of similarity of input and output signals, a Mean Opinion Score (MOS) experiment with fifteen subjects was performed. The Euclidean Distance between spectrums was also measured. Results showed a fair similitude for two tracks and excellent for one. Compression factors above 96% were achieved.Keywords: subband coding, mean opinion score MOS, QMF filter banks, audio compressio

An Analytic Hierarchy Process Based Approach for Evaluating Renewable Energy Sources

Decision-making in energy planning can be approached as a problem of multicriteria decision analysis in which different types of factors are involved. This task must take into account several aspects due to the increasing complexity of social, technological and economic factors. In this context, this paper uses the analytic hierarchy process (AHP) to prioritize a set of criteria, subcriteria and alternatives as a support for decision-making in the process of energy planning with renewable energies for rural areas in the Caribbean region of Colombia. Based on the participation of experts, 5 criteria, 20 subcriteria and 4 alternatives were defined. Using the AHP, the same group of experts was consulted in order to prioritize all aspects. The results showed that the most relevant criteria were the technical with 24.7%. Next were environmental (21.7%), social (19.6%), economic (17.8%) and risk (16.3%). The best renewable energy alternative was solar with 45.3%

An Analytic Hierarchy Process Based Approach for Evaluating Renewable Energy Sources

Decision-making in energy planning can be approached as a problem of multicriteria decision analysis in which different types of factors are involved. This task must take into account several aspects due to the increasing complexity of social, technological and economic factors. In this context, this paper uses the Analytic Hierarchy Process (AHP) to prioritize a set of criteria, subcriteria and alternatives as a support for decision-making in the process of energy planning with renewable energies for rural areas in the Caribbean region of Colombia. Based on the participation of experts, 5 criteria, 20 subcriteria and 4 alternatives were defined. Using the AHP, the same group of experts was consulted in order to prioritize all aspects. The results showed that the most relevant criteria were the technical with 24.7%. Next were environmental (21.7%), social (19.6%), economic (17.8%) and risk (16.3%). The best renewable energy alternative was solar with 45.3%. Keywords: Renewable Energy, Energy Planning, Analytic Hierarchy Process JEL Classifications: Q20, Q42, D70

Comprehensive evaluation of muscular stability and its link to VO2max and body composition in university athletes

Introducción: En el ámbito deportivo, la estabilidad central es crucial para mantener el equilibrio durante la ejecución de movimientos específicos. Pocos estudios han determinado la relación entre rendimiento deportivo, estabilidad y actividad muscular. Objetivo: Explorar la relación entre consumo máximo de oxígeno y factores como la actividad eléctrica de los músculos del core, la composición corporal y la estabilidad central en deportistas universitarios. Materiales y Métodos: Estudio descriptivo y correlacional de corte transversal con deportistas de catorce disciplinas deportivas. Se midieron cinco variables, incluyendo la amplitud máxima de electromiografía de los músculos del core, el área de estabilidad estática y dinámica y el porcentaje de peso muscular. Se utilizaron instrumentos como sensores inalámbricos superficiales electromiograficos, sensores inerciales 3D y equipo de ergoespirometría.Se usó el software Jamovi v 2.3.28.0 para el cálculo de las variables. Resultados: Hubo correlación significativa y positiva entre el porcentaje de peso muscular, la amplitud y el consumo máximos de oxígeno. Al discriminar por disciplina deportiva, se encontraron diferencias en las variables estudiadas. Se observó correlación positiva y significativa entre la amplitud máxima y el porcentaje muscular en todos los deportes, exceptuando el fútbol y el sóftbol. En rugby, se vio una correlación positiva y significativa entre el porcentaje muscular y el consumo máximo de oxígeno. No hubo correlación entre la amplitud del voltaje y la estabilidad en deportistas, lo que muestra que la estabilidad deportiva es más compleja que simplemente centrarse en el core.Conclusión: El estudio redefine la comprensión de la estabilidad y su conexión con el rendimiento deportivo, brindando perspectivas para desarrollar estrategias de entrenamiento efectivas. Es necesario considerar la composición corporal en la evaluación y planificación del entrenamiento para lograr entrenamientos más efectivos.Introduction: In the sports field, core stability is crucial for maintaining balanceduring the execution of specific movements. Few studies have determined therelationship between sports performance, stability, and muscle activity. Objective:To explore the relationship between maximum oxygen consumption and factorssuch as electrical activity of core muscles, body composition, and core stability inuniversity athletes. Materials and Methods: This descriptive and correlationalcross-sectional study involved athletes from fourteen sports disciplines. Fivevariables were measured, including the maximum amplitude of electromyographyof core muscles, the area of static and dynamic stability, and the percentage ofmuscle mass. Instruments such as wireless surface electromyography sensors, 3Dinertial sensors, and ergoespirometry equipment were used. The software Jamoviv 2.3.28.0 was utilized for variable calculation. Results: There was a significantand positive correlation between the percentage of muscle mass, amplitude, and maximum oxygen consumption. When discriminated by sports discipline,differences were found in the studied variables. A positive and significantcorrelation was observed between maximum amplitude and muscle percentage inall sports, except football and softball. In rugby, a positive and significantcorrelation was found between muscle percentage and maximum oxygenconsumption. No correlation was found between voltage amplitude and stability inathletes, indicating that sports stability is more complex than simply focusing on thecore. Conclusion: The study redefines the understanding of stability and itsconnection to sports performance, providing insights for developing effectivetraining strategies. It is necessary to consider body composition in the evaluationand planning of training to achieve more effective workouts

Low-Cost Fuzzy Logic Control for Greenhouse Environments with Web Monitoring

The design and implementation of a low-cost system for monitoring and remote control of a greenhouse using fuzzy logic is presented. For the control system, an Arduino Mega board was programmed with a fuzzy algorithm to monitor and perform control actions for environmental temperature, soil moisture, relative humidity, and lighting. A website was designed to visualize the main indicators of agricultural interest and to get access to tools such as forced ventilation, misting systems, and sprinkler irrigation. For connectivity to the webpage, an Arduino Ethernet Shield was used. Thus, it was possible to establish a local area network and monitor and control the greenhouse climate variables manually or automatically. The application designed allowed access to the configuration, monitoring, and control of climatic conditions in the greenhouse. The effectiveness of fuzzy logic to control nonlinear systems was therefore verified without the mathematical model of the plant. Thus, the use of resources for a gable roof greenhouse prototype was optimized

Un enfoque basado en un proceso de jerarquía analítica para evaluar las fuentes de energía renovables.

Decision-making in energy planning can be approached as a problem of multicriteria decision analysis in which different types of factors are involved. This task must take into account several aspects due to the increasing complexity of social, technological and economic factors. In this context, this paper uses the analytic hierarchy process (AHP) to prioritize a set of criteria, subcriteria and alternatives as a support for decision-making in the process of energy planning with renewable energies for rural areas in the Caribbean region of Colombia. Based on the participation of experts, 5 criteria, 20 subcriteria and 4 alternatives were defined. Using the AHP, the same group of experts was consulted in order to prioritize all aspects. The results showed that the most relevant criteria were the technical with 24.7%. Next were environmental (21.7%), social (19.6%), economic (17.8%) and risk (16.3%). The best renewable energy alternative was solar with 45.3%.La toma de decisiones en la planificación energética se puede abordar como un problema del análisis de decisiones multicriterio en el que intervienen diferentes tipos de factores. Esta tarea debe tener en cuenta varios aspectos debido a la creciente complejidad de los factores sociales, tecnológicos y económicos. En este contexto, este documento utiliza el proceso de jerarquía analítica (AHP) para priorizar un conjunto de criterios, subcriterios y alternativas como apoyo para la toma de decisiones en el proceso de planificación energética con energías renovables para áreas rurales en la región del Caribe de Colombia. Sobre la base de la participación de expertos, se definieron 5 criterios, 20 subcriterios y 4 alternativas. Usando el AHP, se consultó al mismo grupo de expertos para priorizar todos los aspectos. Los resultados mostraron que los criterios más relevantes fueron los técnicos con un 24,7%. Los siguientes fueron: ambiental (21.7%), social (19.6%), económico (17.8%) y riesgo (16.3%). La mejor alternativa de energía renovable fue la solar con un 45,3%