4,035 research outputs found

    Emitter discharge variability of subsurface drip irrigation in uniform soils: effect on water-application uniformity

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    Emitter discharge of subsurface drip irrigation (SDI) decreases as a result of the overpressure in the soil water at the discharge orifice. In this paper, the variation in dripper discharge in SDI laterals is studied. First, the emitter coefficient of flow variation CVq was measured in laboratory experiments with drippers of 2 and 4 L/h that were laid both on the soil and beneath it. Additionally, the soil pressure coefficient of variation CVhs was measured in buried emitters. Then, the irrigation uniformity was simulated in SDI and surface irrigation laterals under the same operating conditions and uniform soils; sandy and loamy. CVq was similar for the compensating models of both the surface and subsurface emitters. However, CVq decreased for the 2-L/h non-compensating model in the loamy soil. This shows a possible self-regulation of non-compensating emitter discharge in SDI, due to the interaction between effects of emitter discharge and soil pressure. This resulted in the irrigation uniformity of SDI non-compensating emitters to be greater than surface drip irrigation. The uniformity with pressure-compensating emitters would be similar in both cases, provided the overpressures in SDI are less than or equal to the compensation range lower limit

    Short CFD simulation activities in the context of fluid-mechanical learning in a multidisciplinary student body

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    17 p.Simulation activities are a useful tool to improve competence in industrial engineering bachelors. Specifically, fluid simulation allows students to acquire important skills to strengthen their theoretical knowledge and improve their future professional career. However, these tools usually require long training times and they are usually not available in the subjects of B.Sc. degrees. In this article, a new methodology based on short lessons is raised and evaluated in the fluid-mechanical subject for students enrolled in three different bachelor degree groups: B.Sc. in Mechanical Engineering, B.Sc. in Electrical Engineering and B.Sc. in Electronic and Automatic Engineering. Statistical results show a good acceptance in terms of usability, learning, motivation, thinking over, satisfaction and scalability. Additionally, a machine-learning based approach was applied to find group peculiarities and differences among them in order to identify the need for further personalization of the learning activity.S

    Effect of agro-climatic conditions on near infrared spectra of extra virgin olive oils

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    Authentication of extra virgin olive oil requires fast and cost-effective analytical procedures, such as near infrared spectroscopy. Multivariate analysis and chemometrics have been successfully applied in several papers to gather qualitative and quantitative information of extra virgin olive oils from near infrared spectra. Moreover, there are many examples in the literature analysing the effect of agro-climatic conditions on food content, in general, and in olive oil components, in particular. But the majority of these studies considered a factor, a non-numerical variable, containing this meteorological information. The present work uses all the agro-climatic data with the aim of highlighting the linear relationships between them and the near infrared spectra. The study begins with a graphical motivation, continues with a bivariate analysis and, finally, applies redundancy analysis to extend and confirm the previous conclusions.Peer Reviewe

    A Musical-Psychosocial Model for attending to Victims of the Armed Conflict in Colombia: Contributions and challenges

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    This article is a product of systematic academic research and explores the contributions and challenges of a musical-psychosocial model developed through the Music for Reconciliation programme run by the Batuta National Foundation in Colombia. The aim of this programme is to attend to the needs of young victims of the armed conflict in Colombia through group music making. Although this dual proposal is extremely valuable for the communities suffering the consequences of the war, challenges have also arisen in its implementation. The study reviews the contributions of the project’s psychosocial component, and explores the possible tensions for social and music professionals seeking to meet the aims established in their respective areas of responsibility. The study raises questions about how musical and psychosocial dimensions can develop a complementary relationship, rather than competing with each other

    Self-Organization through a multi-agent system for orders distribution in large companies

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    This article presents the development of a multi-agent system in charge of self-managing a delivery system. The article focuses on the delivery management system and not on the movement systems of the different used vehicles./nThis system consists of different types of vehicles, each with different characteristics, and there may be several instances of each type of vehicle. There will be three operating agents (Drone Operator, Car Operator and Amphibious Operator), an agent that will be responsible for creating random tasks (used only in simulations) and another one that is responsible for distributing these tasks to the operators taking into account the algorithm. This algorithm follows the bases of backtracking and its main function is to assign a task to a vehicle taking into account the distance, the consumption, the limitations of weight and distances, etc. The whole system has been developed in JADE on java. The described software performs a complete simulation with a console in which it is indicated relevant information such as the tasks that are created, the type of vehicle and the instance of that type of vehicle that resolve the delivery, among others. The purpose of this system is to minimize costs and times

    Realidad virtual en la educación: Matemáticas en tercer grado de primaria

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    Se cumplió con el objetivo señalado en este trabajo de tesis que fue desarrollar una aplicación de RV funcional enfocada al tema de fracciones, que se imparte durante el proceso de enseñanza – aprendizaje a los alumnos de tercer grado de primaria, en México como complemento de las herramientas educativas tradicionales.En la actualidad la tecnología se ha convertido en una herramienta de gran importancia para el ser humano, siendo útil para muchas actividades cotidianas, desde el entretenimiento hasta las actividades laborales. Por ejemplo, en el área educativa a pesar de que los libros y apuntes constituyen el soporte de la enseñanza; las computadoras personales, los Smartphone, las tabletas electrónicas y el internet se están empleando para facilitar la docencia de los profesores y el aprendizaje de los estudiantes, incluyéndose de esta manera en el entorno educativo

    Administración y contabilización de los bienes incautados en Colombia

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    71 páginas : ilustraciones, gráficos.En Colombia existe una problemática muy marcada la cual va relacionada con la administración y la manera de registrar los bienes incautados en Colombia, infortunadamente el control ejercido sobre la Dirección Nacional de Estupefacientes no es el más adecuado y permite tener muchos vicios sobre la forma y el resultado que se da en el proceso que surte desde la incautación hasta la enajenación de los bienes incautados. De esta manera surge la inquietud acerca de los factores que inciden sobre la administración y registro de los bienes incautados en Colombia y como desde la Ley 785 de 2002, se define el derrotero a seguir, a través de todo el proceso realizado por la Dirección Nacional de Estupefacientes, apoyado por el Decreto 1461 del 2000 (Decreto 1461, 2000), por el cual se define el sistema de administración y enajenación de los bienes incautados en Colombia. (Ley 785, 2002)ln Colombia there is a very specific problem for the registration of assets seized in Colombia, unfortunately the control exercised over Direccion Nacional de Estupefacientes is not the most appropriate and allows many errors about the form and result that occurs in the process that It occurs from the seizure to the alienation of the seized assets. Thus, the concern about the factors that affect the administration and registration of assets seized in Colombia and Law 785 of 2002, the course to be followed is defined, through the entire process carried out by the Direccion National de Estupefacientes, supported by Decree 1461 of 2000, by which the system of administration and alienation of assets seized in Colombia. (Law 785, 2002)Contador PúblicoPregrad

    Short simulation activity to improve the competences in the Fluid-mechanical Engineering classroom using Solidworks ® Flow Simulation

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    7 p.In this paper, a short simulation activity based on Computational Fluid Dynamics (CFD) is raised in the context of the Mechanical Engineering Bachelor degree as an effective support to the theoretical lessons, in order to improve the competences of the Fluid-Mechanical course. The activity provides both visual and numerical information that the student must compare critically with respect the results obtained analytically, using the equations explained in the theoretical classroom. The activity is designed so that it can be integrated quickly (due to the shortage of times in the academic calendars). In this manner its total completion does not exceed four hours of simulation class. This is achieved by optimizing the resources, proposing meshing and simulation strategies that consume little computational time and using the package Solidworks® Flow Simulation, that takes advantage of the geometry parametrically modelled with the software itself to automatically establish the computational domain of the fluid for the based-on CFD analysis, saving excessive preparation times and long computational process.S

    El impuesto dual: argumentos teóricos e implicaciones de política fiscal

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    Entre 1987 y 1993 los países escandinavos llevaron a cabo importantes reformas de sus IRPF, pasando de modelos formalmente sintéticos a modelos duales que gravan progresivamente las rentas de trabajo y proporcionalmente las de capital. Pese a la innovación que supuso en su día la adopción de estos modelos, no ha tenido lugar desde entonces un debate de fondo sobre las ventajas e inconvenientes de los mismos. En este trabajo se realiza una revisión de los argumentos que se han utilizado hasta ahora como justificación del Modelo Dual y de los estudios empíricos que han examinado sus efectos. El objetivo final es determinar si nos encontramos ante una opción reformista viable o si, al menos, es posible extraer alguna conclusión parcial de interés en términos de política fiscal.: Reforma del IRPF; impuesto dual; política fiscal.

    Preservación de la diversidad y manejo de los puntos de referencia en algoritmos evolutivos multiobjetivo

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    El éxito de los algoritmos evolutivos multiobjetivo basados en descomposición (MOEA/D) ha generado un gran interés en los MOEA que utilizan un conjunto de vectores de peso para promover la diversidad dentro de las soluciones no dominadas. Sin embargo, la calidad del conjunto de soluciones obtenido depende en gran medida de la consistencia entre la forma del frente de Pareto del problema y la distribución de peso especificada. El objetivo de este trabajo es doble. En primer lugar, el estudio se centra en seis técnicas clásicas para la generación de vectores de peso, ya sea basadas en el diseño de mezclas o en secuencias de baja discrepancia. El rendimiento de estos métodos, implementados en MOEA/DconPBI, se evaluó y analizo en varias funciones de prueba escalables de la literatura. Además, se introduce un enfoque novedoso para actualizar los vectores de peso durante el proceso evolutivo, que utiliza información de los individuos no dominados de la población actual. Estas soluciones se utilizan para volver a calcular su vector de peso correspondiente y marcarlas como puntos prohibidos o tabú. Luego, se crean nuevos vectores de peso lejos de estos puntos tabú a través de un criterio de repulsión basado en la distancia de Mahalanobis. Algunos experimentos preliminares indican que esta estrategia de adaptación dinámica del vector de peso proporciona beneficios significativos en comparación con el diseño estático Simplex Lattice ampliamente utilizado pero que ha mostrado problemas en altas dimensiones
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