Problemática socio-económica de la mano de obra en explotaciones radicadas en zonas marginales de la provincia de Córdoba

Se estudia la cifra de ventas por UTII en cuatro diferentes acllvidadcs que se realizan en las zonas marginales de la provincia de Córdoba, éstas son, cría de ovinos, caprinos, cotos de caza menor y cotos de cala mayor. Asimismo se considera el coste social de las actividades pastor, cabrero y g11arda

Marijuana, stigma and social rejection: notes for a genealogy on condemnation of psychoactive cannabis users in Mexico

Objetivo: cuestionar la condena social del consumo de mariguana dada durante la historia de México. Se parte de la tesis de que el estigma y la exclusión social, tal como se entienden en la sociedad mexicana, nacen en el siglo XIX. Resultados: se realizó una contribución a la construcción de la genealogía de esta condena desde fuentes que analizan la esferas social y cultural de la historia mexicana de las drogas en general y de la mariguana en particular. Metodología: el artículo es fruto de una investigación documental-genealógica. El argumento se apoya en dos categorías sociológicas que facilitan comprender el fenómeno en cuestión. Conclusión: los prejuicios y estigmas al consumo de mariguana no tienen base objetiva, ni corresponden con las realidades de los usuarios. La presencia histórica del estigma y de los prejuicios dificulta la transición hacia una sociedad posprohibicionista, que establezca otro ethos del consumo de mariguana.Objective: To question the social condemnation of marijuana consumption given during the history of Mexico. The study is supported on the basis of the thesis that stigma and social exclusion, as understood in Mexican society, were born in the 19th century. Results: A contribution was made to the construction of the genealogy of this conviction from sources that analyze the social and cultural spheres of the Mexican history of drugs in general, and of marijuana in particular. Methodology: the article is the result of a documentary-genealogical research. The argument is supported by two sociological categories that facilitate understanding the phenomenon in question. Conclusion: the prejudices and stigmas related with the consumption of marijuana do not have an objective basis neither they correspond to the realities of the users. The historical presence of stigma and prejudice makes the transition towards a postprohibitionist society difficult, which establishes another ethos of marijuana use

El empleo de la cascarilla de algodón en la alimentación de ganado bovino de cebo

Los autores realizan una experiencia de cebo sobre e1nco lotes de bovinos de raza frisona y retinta, con un total de 137 animlles, empleando como alimentos cascarilla de algodón, y cascarilla de algodón más un 30 por 100 de mazorca integral de maiz. Se obtienen incrementos diarios de 1,09 Kg con un consumo energético de 21,7 Mcal/cabeza y día. Los resultados satisfactorios obtenidos, deben atribuirse, fundamentalmente, al alto valor nutritivo de la cascarilla empleada

Chemical composition and structural changes of porous templates obtained by anodising aluminium in phosphoric acid electrolyte

Ordered anodic aluminium oxide (AAO) filmswere first prepared by anodising in a phosphoric acid electrolyte and then studied extensively and characterised by field emission gun-scanning electron microscopy (FEG-SEM), X-ray diffraction, Raman and infrared spectroscopy at a macroscopic scale. These analyses showed that the as-prepared AAO film is in fact amorphous, partially hydrated and that its initial global chemical composition can be described, in agreement with previous works, as: Al2O3, 0.186AlPO4 · 0.005H2O. Additional analyses (thermogravimetric analysis, differential thermal analysis and FEG-SEM) showed geometrical changes of the film structure at different scales, explained by various steps of dehydration and allotropic transformations of the resulting crystallised alumina. However, because their structure remains unchanged up to 900 ◦C, the phosphoric templates appear to be particularly suitable for applications or processes atmedium or high temperatures, such as the preparation of carbon nanotubes or oxide rods

Análisis de Riesgos Ocupacionales en Aserraderos.

Proyecto de Investigación. Instituto Tecnológico de Costa Rica. Escuela de Ingeniería en Seguridad Laboral e Higiene Ambiental, Laboratorio de Higiene Analítica; Instituto Nacional de Seguros. Departamento de Gestión Empresarial en Salud Ocupacional , 2013Occupational respiratory diseases and nasal cancer are among the major work-related illnesses associated to wood dust exposure. This study will allow a systematic assessment of working conditions in the areas of safety, ergonomics and occupational exposure to chemical and biological agents in sawmills located throughout the country, in order to characterize the main risks and generate information leading to decrease the hazards in favor of the health and safety of workers. For safety assessments checklists and questionnaires were used, photographs and videos for the ergonomic assessment using REBA and OWAS methodologies, measuring equipment for collecting samples of wood dust exposure according to the method MDHS 14/3 subsequently analyzed in the Laboratory of Analytical Hygiene and samples of biological agents according to Pouch (2003) in the Food Laboratory of the University of Costa Rica. The results of compliance for working conditions did not exceed 60 %. For the ergonomic evaluation by REBA method, it was estimated that 95.8 % of workers (n = 92) were found above the ergonomic low risk category. By the OWAS method similar results were obtained. The wood dust concentrations were found in a range of 0.09 to 28.9 mg/m3, with an MLE estimate of 2.33 mg/m3 exceeding national and international regulations. Species of fungi and bacteria were found in samples of wood dust: Aspergillus, Bacillum, and Penicilinum. Is recommended to develop and implement improvement measures in all areas evaluated to prevent injuries and illnesses among sector workers, such as the implementation of safe work practices and training, among others.Las enfermedades respiratorias y el cáncer nasal se encuentran entre las afecciones ocupacionales asociadas con la exposición a polvo de madera. El presente estudio permitió valorar, de forma exploratoria, algunos agentes químicos y biológicos, condiciones de seguridad y ergonomía que podrían estar afectando la salud de los trabajadores de los aserraderos. Se utilizaron listas de verificación y cuestionarios para las evaluaciones de seguridad; fotografías y videos para la evaluación ergonómica según las metodologías REBA y OWAS; equipo de medición para la recolección de muestras de exposición a polvo de madera según el método MDHS 14/3, analizadas posteriormente en el Laboratorio de Higiene Analítica y las muestras de agentes biológicos según Pouch (2003) en el Laboratorio de Alimentos de la Universidad de Costa Rica. Los resultados de porcentaje de conformidad ponderado por empresa para las condiciones de trabajo no superaron el 60% de conformidad. Según la evaluación ergonómica a partir del método REBA, se estimó que 95,8% de los trabajadores (n=92) se encontraron sobre la categoría de riesgo ergonómico bajo. Por el método OWAS se obtuvieron resultados similares. Las concentraciones de polvo de madera se encontraron en un rango de 0,09 – 28,9 mg/m3 , con un MLE estimado de 2,33mg/m3 , superando los límites de exposición establecidos, tanto a nivel nacional como internacional. Se encontraron especies de hongos y bacterias en las muestras de polvo de madera: Aspergillus, Penicilinum y Bacillum. Se recomienda establecer medidas de mejora en todas las áreas evaluadas, para prevenir lesiones por accidentes de trabajo y enfermedades entre los colaboradores del sector, como por ejemplo la implementación de prácticas seguras de trabajo y capacitación, entre otros.Instituto Tecnológico de Costa Rica

Optimal Reconfiguration of a Limited Parallel Robot for Forward Singularities Avoidance

[EN] The positioning of the anchoring points of a Parallel Kinematic Manipulator has an important impact on its later performance. This paper presents an optimization problem to deal with the reconfiguration of a Parallel Kinematic manipulator with four degrees of freedom and the corresponding algorithms to address such problem, with the subsequent test on an actual robot. The cost function minimizes the forces applied by the actuators along the trajectory and considers singular positions and the feasibility of the active generalized coordinates. Results are compared among different algorithms, including evolutionary, heuristics, multi-strategy and gradient-based optimizers.This work was supported by the Spanish Ministry of Education, Culture and Sports through the Project for Research and Technological Development with Ref. DPI2017-84201-RLlopis-Albert, C.; Valero, F.; Mata, V.; Escarabajal, RJ.; Zamora-Ortiz, P.; Pulloquinga, JL. (2020). Optimal Reconfiguration of a Limited Parallel Robot for Forward Singularities Avoidance. Multidisciplinary Journal for Education, Social and Technological Sciences. 7(1):113-127. https://doi.org/10.4995/muse.2020.13352OJS11312771Arakelian, V., Briot, S., & Glazunov, V. (2008). Increase of singularity-free zones in the workspace of parallel manipulators using mechanisms of variable structure. Mechanism and Machine Theory, 43(9), 1129-1140. https://doi.org/10.1016/J.MECHMACHTHEORY.2007.09.005Araujo-Gómez, P., Díaz-Rodríguez, M., Mata, V., & González-Estrada, O. A. (2019). Kinematic analysis and dimensional optimization of a 2R2T parallel manipulator. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 41(10), 425. https://doi.org/10.1007/s40430-019-1934-1Araujo-Gómez, P., Mata, V., Díaz-Rodríguez, M., Valera, A., & Page, A. (2017). Design and kinematic analysis of a novel 3UPS/RPU parallel kinematic mechanism with 2T2R motion for knee diagnosis and rehabilitation tasks. Journal of Mechanisms and Robotics, 9(6), 061004. https://doi.org/10.1115/1.4037800Beiranvand, V., Hare, W., & Lucet, Y. (2017). Best practices for comparing optimization algorithms. Optimization and Engineering, 18(4), 815-848. https://doi.org/10.1007/s11081-017-9366-1Dash, A. K., Chen, I. M., Yeo, S. H., & Yang, G. (2005). Workspace generation and planning singularity-free path for parallel manipulators. Mechanism and Machine Theory, 40(7), 776-805. https://doi.org/10.1016/j.mechmachtheory.2005.01.001Gosselin, C., & Angeles, J. (1990). Singularity Analysis of Closed-Loop Kinematic Chains. IEEE Transactions on Robotics and Automation, 6(3), 281-290. https://doi.org/10.1109/70.56660Llopis-Albert, C., Rubio, F., & Valero, F. (2018). Optimization approaches for robot trajectory planning. Multidisciplinary Journal for Education, Social and Technological Sciences, 5(1), 1. https://doi.org/10.4995/muse.2018.9867Patel, Y. D., & George, P. M. (2012). Parallel Manipulators Applications-A Survey. Modern Mechanical Engineering, 02(03), 57-64. https://doi.org/10.4236/mme.2012.23008Rubio, F., Llopis-Albert, C., Valero, F., & Suñer, J. L. (2016). Industrial robot efficient trajectory generation without collision through the evolution of the optimal trajectory. Robotics and Autonomous Systems, 86, 106-112. https://doi.org/10.1016/j.robot.2016.09.008Rubio, F., Valero, F., & Llopis-Albert, C. (2019). A review of mobile robots: Concepts, methods, theoretical framework, and applications. International Journal of Advanced Robotic Systems, 16(2), 172988141983959. https://doi.org/10.1177/1729881419839596Tsai, L.-W. (1999). Robot Analysis and Design. John Wiley & Sons, Inc. New York, NY, USA ©1999.Valero, F., Rubio, F., & Llopis-Albert, C. (2019). Assessment of the Effect of Energy Consumption on Trajectory Improvement for a Car-like Robot. Robotica, 37(11), 1998-2009. https://doi.org/10.1017/S0263574719000407Vallés, M., Araujo-Gómez, P., Mata, V., Valera, A., Díaz-Rodríguez, M., Page, Á., & Farhat, N. M. (2018). Mechatronic design, experimental setup, and control architecture design of a novel 4 DoF parallel manipulator. Mechanics Based Design of Structures and Machines, 46(4), 425-439. https://doi.org/10.1080/15397734.2017.1355249Wehage, K. T., Wehage, R. A., & Ravani, B. (2015). Generalized coordinate partitioning for complex mechanisms based on kinematic substructuring. Mechanism and Machine Theory, 92, 464-483. https://doi.org/10.1016/j.mechmachtheory.2015.06.006www.esteco.com. (n.d.). Retrieved June 10, 2019, from https://www.esteco.com/Xianwen Kong, B., & Gosselin, C. M. (2002). Kinematics and singularity analysis of a novel type of 3-CRR 3-DOF translational parallel manipulator. International Journal of Robotics Research, 21(9), 791-798. https://doi.org/10.1177/02783649020210090501Yang, X. (2017). Optimization Algorithms Optimization and Metaheuristic Algorithms in Engineering. (March). https://doi.org/10.1007/978-3-642-20859-

Healthy Sitting Behaviour Enhancement using a Smart Chair System

The aim of this paper is to present a smart chair prototype to monitor the sitting behaviour of people in wheelchair to re-educate them about long periods of time standing still and in the same position and giving them a feedback about this. The project is mainly focused on those who have been in a wheelchair for a short time. The sitting posture monitoring in the developed smart chair system can help or promote people to achieve and maintain healthy sitting behaviour, and prevent or reduce diseases caused by poor sitting behaviour, like bedsores (pressure ulcers)

Gen-FW: Una generalización del problema de Fermat-Weber con aplicaciones al procesamiento de datos

The project "Gen-FW: A Generalization of the Fermat-Weber Problem with Applications to Data Processing" was a project affiliated with the Vicerrectoría de Investigación y Extensión (VIE) of the Instituto Tecnológico de Costa Rica during the years 2020-2022. This project proposes a generalization of the well-known Fermat-Weber problem, or simply the FW problem, in addition to studying computational aspects and applications in image processing. The FW problem calculates a vector that minimizes the sum of weighted distances with respect to other given vectors in a vector space, where the vector to be optimized is represented by a linear transformation. The FW problem has garnered growing interest due to its valuable applications in various engineering fields, such as in navigation algorithm design and establishing connectivity in mobile networks with wireless sensors, among other relevant applications. In this article, we will provide a concise yet comprehensive overview of the contributions obtained during the development of this project. The Gen-FW project offers a new perspective in the field of data processing and represents a significant advancement in solving complex problems with practical applications in various engineering areas.El proyecto "Gen-FW: Una generalización del problema de Fermat-Weber con aplicaciones al procesamiento de datos" fue un proyecto vinculado a la Vicerrectoría de Investigación y Extensión (VIE) del Instituto Tecnológico de Costa Rica durante los años 2020-2022. Este proyecto propone una generalización del conocido problema de Fermat-Weber, o simplemente problema FW, además de estudiar aspectos computacionales y aplicaciones en el procesamiento de imágenes. El problema FW calcular un vector que minimice la suma de distancias ponderadas respecto a otros vectores dados en un espacio vectorial, donde el vector a optimizar se representa mediante una transformación lineal. El problema FW ha sido objeto de un creciente interés debido a sus valiosas aplicaciones en diversas áreas de la ingeniería, por ejemplo, en el diseño de algoritmos de navegación y en el establecimiento de la conectividad de redes móviles con sensores inalámbricos, entre otras aplicaciones relevantes. En este artículo, proporcionaremos un conciso, pero completo desarrollo de las contribuciones obtenidas durante el desarrollo de dicho proyecto. El proyecto Gen-FW ofrecen una nueva perspectiva en el ámbito del procesamiento de datos y representan un avance notable en la resolución de problemas complejos con aplicaciones prácticas en diversas áreas de la ingeniería

Identification of Inertial Parameters for Position and Force Control of Surgical Assistance Robots

[EN] Surgeries or rehabilitation exercises are hazardous tasks for a mechanical system, as the device has to interact with parts of the human body without the hands-on experience that the surgeon or physiotherapist acquires over time. For various gynecological laparoscopic surgeries, such as laparoscopic hysterectomy or laparoscopic pelvic endometriosis, Uterine Manipulators are used. These medical devices allow the uterus to be suitably mobilized. A gap needs to be filled in terms of the precise handling of this type of devices. In this sense, this manuscript first describes the mathematical procedure to identify the inertial parameters of uterine manipulators. These parameters are needed to establish an accurate position and force control for an electromechanical system to assist surgical operations. The method for identifying the mass and the center of mass of the manipulator is based on the solution of the equations for the static equilibrium of rigid solids. Based on the manipulator inertial parameter estimation, the paper shows how the force exerted by the manipulator can be obtained. For this purpose, it solves a matrix system composed of the torques and forces of the manipulator. Different manipulators have been used, and it has been verified that the mathematical procedures proposed in this work allow us to calculate in an accurate and efficient way the force exerted by these manipulators.The authors wish to thank the "Agencia Valenciana de la Innovacio" (Generalitat Valenciana) for the partial funding of this study under the project with reference INNCON00/20/002. We also want to thank the "Instituto Universitario de Automatica e Informatica Industrial (ai2)" of the "Universitat Politecnica de Valencia" for its financial support under the program "Plan de ayudas a la I+D+I del Instituto ai2".Zamora-Ortiz, P.; Carral-Alvaro, J.; Valera Fernández, Á.; Pulloquinga-Zapata, J.; Escarabajal-Sánchez, RJ.; Mata Amela, V. (2021). Identification of Inertial Parameters for Position and Force Control of Surgical Assistance Robots. Mathematics. 9(7):1-16. https://doi.org/10.3390/math9070773S1169

Imitation Learning-Based System for the Execution of Self-Paced Robotic-Assisted Passive Rehabilitation Exercises

[EN] The development of robotic-assisted rehabilitation exercises involving physical human-robot interaction requires extreme care since an injured limb may be in physical contact with the robot, so compliant behavior is imperative for these tasks. Typical approaches involve force control schemes like admittance controllers that allow humans to adapt the motion. However, when the patient¿s limb has limited mobility or is potentially injured, unintentional forces may occur during the robot¿s trajectory that could be incompatible with these controllers. This letter addresses a new way of generating compliant trajectories for passive rehabilitation exercises, considering that previous positions of the trajectory are attainable for the patient, so reversing the trajectory is a safe op eration. Since there is no clear way to optimize such a goal due to the physiological variability among patients, the condition of reversal is based on imitation learning by taking the analogous healthy limb of the patient as a reference and encoding the forces using Gaussian Mixture Regression, and reversibility is accomplished by means of Reversible Dynamic Movement Primitives. The system allows for self-paced rehabilitation exercises by back-and-forth movements along the trajectory according to the patient¿s reaction, and it has been successfully applied to a 4-DOF parallel robot for lower-limb rehabilitation.This work was supported in part by the Fondo Europeo de Desarrollo Regional under Grant PID2021-125694OB-I00, in part by the Vicerrectorado de Investigación de la Universitat Politècnica de València under Grant PAID-11-21, and in part by the Ministerio de Universidades, Gobierno de España under Grant FPU18/05105Escarabajal-Sánchez, RJ.; Pulloquinga-Zapata, J.; Zamora-Ortiz, P.; Valera Fernández, Á.; Mata Amela, V.; Vallés Miquel, M. (2023). Imitation Learning-Based System for the Execution of Self-Paced Robotic-Assisted Passive Rehabilitation Exercises. IEEE Robotics and Automation Letters. 8(7):4283-4290. https://doi.org/10.1109/LRA.2023.3281884428342908