562 research outputs found

    Stochastic modelling of monthly sun bright in coffee growing areas

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    Se ajustaron modelos ARIMA a series mensuales de brillo solar obtenidas en 32 estaciones meteorológicas de la Federación Nacional de Cafeteros de Colombia. La estructura de los modelos ajustados fue ARIMA(0; 1; 1)*(0; 1; 1)12 de promedios móviles con componente estacional de 12 meses. Los parámetros estimados fueron suficientes para describir el comportamiento de la serie. Los pronósticos obtenidos fueron muy cercanos de los valores observados, actualizados mensualmente. Esta característica permite reajustar el modelo cuando haya cambios en el patrón de la serie y planificar actividades relacionadas con la absorción de la energía solar. El mayor error de pronóstico fue de 23 %, considerado como aceptable.Autorregressive integrated moving average models ARIMA, were adjusted to series of monthly sun bright for 32 meteorological stations of The National Federation of Coffee Growers of Colombia. The structure of the adjusted models was ARIMA(0; 1; 1) * (0; 1; 1)12 this is a moving average with a seasonality component each 12 month, the estimated parameters were sufficient to describe the behavior of the series, they were statistically different from zero and non correlated. The estimated forecasts were found very approximated to observed values, they are actualized monthly, this characteristic allow to readjust the model when the pattern series change and to plan activities related with absorption of solar energy. The greatest forecast error was 23% and it is considered acceptable

    Modelo de rendimiento potencial del cultivo de plátano (musa aab simmonds)

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    El plátano es un producto básico en la alimentación para más de 400 millones de habitantes de las regiones tropicales y subtropicales del mundo. Los modelos del desarrollo de cultivos se han convertido en una herramienta de mucha utilidad para investigadores que estudian procesos fisiológicos básicos, y agricultores que los usan en la toma de decisiones para el manejo del cultivo. Con el objetivo de desarrollar un modelo de producción potencial de plátano, se usaron los datos de dos experimentos con la variedad Dominico-Hartón en Colombia, en los cuales se midieron variables fisiológicas de crecimiento y desarrollo, así como variables climáticas. Con base en los resultados se estimó el coeficiente de extinción de la luz (k) en 0,2817 y el uso eficiente de la luz (LUE) en 1,63 g MJ-1 . En la etapa vegetativa, las hojas, el tallo y el cormo incrementaron su materia seca por partes iguales, pero en la etapa reproductiva las hojas y el cormo perdieron masa, mientras que el tallo continuó en aumento, aunque no tan aceleradamente como en la primera etapa. Del análisis de sensibilidad se deduce que LUE es el parámetro más sensible y, por lo tanto, los esfuerzos se deben dirigir a mejorar la conversión de luz incidente en materia seca

    Philosophical and methodological aspects of Operations Research: the evolution of an interdisciplinary area

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    Operations Research fits into the history of the great technological and scientific events of the twentieth century. Its influence on the emergence of other sciences and applications, whose developments in the post-war period contributed to the increased rationalization of modern society are evident. Given this context, this article aims to trace an analytical reconstruction on the philosophical and methodological aspects that mark the history of operations research. Such reconstruction will be developed based on a historical method using bibliography and documents. The refinement of Operations Research techniques was a determining factor for its success, and its methodological and philosophical aspects have revered thinkers such as John Dewey, Churchman, and Capra, who are references to understand modern men's thought. It turns out that World War II was determinant for science in general and more specifically for the great advance of operations research. The achievements of the OR, largely, result from the formation of multidisciplinary groups that allowed the evolution of the area in several directions, providing an interdisciplinary dialogue

    Cartografia, autoficção e catarse : 7 experiências

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    Dissertação (mestrado)—Universidade de Brasília, Instituto de Artes, Programa de Pós-Graduação em Artes, 2018.Esta dissertação tem como proposta investigar a relação entre a autoficção e a catarse na prática da cartografia artística. Para tal, são apresentadas sete cartografias artísticas de autoria própria, com obras em pintura, desenho, contos, intervenção urbana, roteiro cinematográfico e escultura. São também apresentadas e relacionadas obras de outros artistas. A autoficção é apresentada segundo recorte teórico proposto por Vincent Collona (2014) no primeiro capítulo, O Pé de Bico; suas exemplificações teóricas na literatura são utilizadas, mas busca-se também paralelos em outras linguagens, como um roteiro de curta-metragem e pinturas, de autoria própria, além de obras visuais de outros artistas como Johannes Gumpp (1626 – 1646), Katsushika Hokusai (1760-1849), Edgar Degas (1834 – 1917), Rafael Sanzio (1483 – 1520), Van Gogh (1853 – 1890), dentre outros. O segundo capítulo, intitulado Paralisia do Sono, aborda o conceito de experiência segundo Dewey (1980) e é exemplificado com pinturas próprias feitas a partir da vivência desse distúrbio do sono. A linguagem como possibilidade de criação de novas realidades é o tema de investigação na produção textual; essa relação é pensada a partir do autor Vilém Flusser (2007) no terceiro capítulo, chamado: Os Contos de Santa Luzia Cega. Malafetty: do Cafezinho na Sala dos Professores à Galeria de Arte é o nome do quarto capítulo, que exemplifica a relação entre vivência cotidiana, estetização da experiência e exposição desse resultado em galeria de arte; aponta-se possíveis aproximações da produção com a arte bruta, a charge e a caricatura. A cartografia artística é trabalhada a partir de Sueli Rolnik (2011) em consonância com instâncias do conhecimento sensível numa perspectiva fenomenológica no quinto capítulo, nomeado Tuberculose Ocular, em função da vivência dessa situação. A questão do tempo na cartografia artística é trabalhada no sexto capítulo Uma Barata: Desdobramentos Desta Experiência. O tema da catarse figura principalmente na cartografia empreendida no processo artístico Debanda (2017), sétimo capítulo desta dissertação, tendo ancoragem teórica principalmente em Aristóteles, Antonin Artaud, Patrice Pavis, dentre outros.This dissertation aims to investigate the relationship between autofiction and catharsis in the practice of artistic cartography. For this, seven artistic cartographies of own authorship are presented, with works in painting, drawing, short stories, urban intervention, cinematographic script and sculpture. Other works by other artists are also presented and related. The autofiction is presented according to the theoretical cut proposed by Vincent Collona (2014) in the first chapter, Nozzles Foot (Pé de Bico); his theoretical exemplifications in the literature are used, but he also seeks parallels in other languages, such as a screenplay of short films and paintings, by his own authors, as well as visual works by other artists such as Johannes Gumpp (1626-1646), Katsushika Hokusai (1760-1849), Edgar Degas (1834-1917), Rafael Sanzio (1483-1520), Van Gogh (1853-1890), among others. The second chapter, entitled Sleep paralysis (Paralisia do Sono), approaches the concept of experience according to Dewey (1980) and is exemplified with his own paintings made from the experience of this sleep disorder. Language like the possibility of creating new realities is the subject of research in textual production; this relationship is thought from the author Vilém Flusser (2007) in the third chapter, called: The Tales of Saint Luzia Blind (Os Contos de Santa Luzia Cega). Malafetty: from Cafezinho in the Teachers' Hall to the Art Gallery (Malafetty: do Cafezinho na Sala dos Professores à Galeria de Arte) is the name of the fourth chapter, which exemplifies the relationship between daily living, aestheticizing the experience and exposing this result in an art gallery; it’s point out possible approximations of the production with the gross art, the cartoon and the caricature. Artistic cartography is based on Sueli Rolnik (2011) in consonance with instances of sensitive knowledge in a phenomenological perspective in the fifth chapter, named Ocular Tuberculosis (Tuberculose Ocular), in function of the experience of this situation. The question of time in artistic cartography is worked out in the sixth chapter One Cockroach: Outfits of This Experience (Uma Barata: Desdobramentos Desta Experiência.). The theme of catharsis is found mainly in the cartography undertaken in the artistic process Debanda (2017), the seventh chapter of this dissertation, with theoretical anchorage mainly in Aristotle, Antonin Artaud, Patrice Pavis, among others

    Una prueba de hipótesis en modelos no lineales con variables retrasadas

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    En este estudio se usa el criterio de Wald y el procedimiento de estimación de los parámetros de interés en un modelo de regresión no lineal con estructura autorregresiva de orden q en los errores, propuestos por Gallant y Goebel (5), para probar hipótesis sobre funciones de los parámetros. Mediante algunas transformaciones se logra reducir un modelo no lineal de series de tiempo autorregresivo en primer orden, al cual se le aplican los procedimientos anteriores para estimar los parámetros y su respectiva inferencia.In the present work the Wald's criterium is used and the estimation procedure for the interest parameters in a non-linear regression model with autorregresive structure of order q in the errors, proposed by Gallant and Goebel (5), in order to test hypotesis about functions of the parameters. Using some transformations in a non-linear model of autorregresive times series of first average in the errors; the above procedures are applied for estimating its parameters and its respective inferences

    Editorial

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    EVALUACIÓN DE SEIS SISTEMAS DE SANGRÍA PARA CUATRO CLONES DE Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg., EN LA ALTILLANURA COLOMBIANA

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    The rubber yield of four Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. clones was evaluated on the Colombian high plains in the Meta department: ian 873 and rrim 600 (third year of tapping being done) and pb 260 and gt 1 (first year of tapping). Six tapping systems were used, including a combination of different tapping frequencies (d/4 and d/5), Ethephon concentrations (0%, 2.5%, 3.3% and 5%) and a number of applications per year (4 to 8) were also used depending on the clone. The production figures for one commercial year were obtained from assays, using a completely randomblock design (having four repetitions) independently defined for each clone: having on average 4446 g rubber/tree of produce per year for the rrim 600 clone within a system ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g rubber/tree for the pb 260 clone with ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g rubber/tree for the ian 873 clone, ½S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, and 3472 g rubber/ tree for the gt 1 clone, ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. The highest produce was obtained with a four-day tapping frequency.Este trabajo evaluó el desempeño productivo de cuatro clones de caucho natural (Hevea brasiliensis [Willd. ex Adr. de Juss.] Muell.-Arg.), sometidos a seis diferentes sistemas de sangría, los cuales incluyeron la combinación de dos diferentes frecuencias de sangrado cada cuatro y cinco días (d/4 y d/5) y cuatro concentraciones de Ethefon (0%, 2.5%, 3.0% y 5%) con un número de aplicaciones entre 4 a 8 veces por año. Los ensayos se realizaron en la plantación de la empresa mavalle s.a., ubicada en la altillanura colombiana, bajo un diseño de bloques completos al azar con cuatro repeticiones. Se obtuvieron producciones promedio por año de 4446 g de caucho/árbol para el clon rrim 600 en un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 7/y; 2696 g de caucho/árbol para el clon pb 260 bajo un sistema ½S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y; 3822 g de caucho/árbol para el clon ian 873 en un sistema ½ S, d/4, 6d/7, 10m/12, et 3.3%, Pa 8/y, y 3472 g de caucho/árbol para el clon gt 1 bajo una sistema ½ S, d/4, 6d/7, 10m/12, et 2.5%, Pa 5/y. Se obtuvo la mayor producción en una frecuencia de sangrado cada cuatro días para los clones RRIM 600, gt 1 y pb 260

    Agronomic performance and cooking quality characteristics for slow-darkening pinto beans

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    Slow-darkening (SD) pinto beans (Phaseolus vulgaris L.) possess a desirable new trait, conditioned by the recessive sd gene, that slows seed coat darkening under delayed harvest and under storage. The effect sd may have on performance needs investigation. We examined agronomic performance and cooking quality of SD pinto beans. There were 30 (15 SD and 15 regular darkening [RD]) recombinant inbred lines (RILs) from each of two biparental inbred populations. The 60 RILs were tested across three locations in North Dakota andWashington. In addition, advanced SD and RD pinto breeding lines were tested in trials from 2010 to 2012 and in 2018. Across 2010–2012 trials, the “early generation bred” SD pintos, as a group, had significantly lower emergence, increased lodging, less seed yield, and smaller seed size than the RD group. Conversely, in the 2018 trial, “recently bred” SD pinto breeding lines had competitive agronomic performance to RD lines for seed yield, reduced lodging, and increased emergence. Further research on cooking time is warranted given that SD RILs cooked 20% faster than the RD RILs in one population. Overall, SD pintos exhibited slightly better canning quality than RD pintos. Whether raw or cooked, SD pintos were much lighter in color than RD pintos, emphasizing the need to keep them separated as distinct market classes. Breeders should continue to focus on improving agronomic performance for emergence, lodging, seed yield, seed size, and canning quality of SD pinto beans

    Dos agentes con algoritmos GBFS trabajando de forma cooperativa para obtener la ruta más corta

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    This study is carried out in order to verify if the implementation of the concept of cooperative work among two agents, that use path planners A* to obtain the shortest path (previous work of the authors) is also valid when the cooperative strategy is applied using another path planner such as the so-called GBFS (Greedy Best First Search). In this sense, this paper shows a path planning strategy that combines the capabilities of two Agents each one with its own path planner GBFS (slightly different from each other) in order to obtain the shortest path. The comparisons between paths are made by analyzing the behavior and results obtained from the agents operating in different forms: (1) Working individually; (2) Working as a team (cooperating and exchanging information). The results show that in all analyzed situations are obtained shortest traveled distances when the path planners work as a cooperative team.Este estudio se lleva a cabo con el fin de verificar si la implementación del concepto de trabajo cooperativo entre dos agentes, usado con planificadores A* para obtener la ruta más corta (trabajo previo de los autores) también es válida cuando la estrategia cooperativa es aplicada usando otro planificador de rutas como el llamado GBFS (Greedy Best First Search). En este sentido, el articulo muestra una estrategia de planificación de rutas que combina las capacidades de dos agentes cada uno con su propio planificador de rutas GBFS (ligeramente diferentes entre sí) para obtener la ruta más corta. La comparación entre las dos rutas se realiza analizando el comportamiento y comparando los resultados obtenidos para cada uno de los que operan en diferentes formas: (1) Trabajando individualmente; (2) Trabajando como un equipo (cooperando e intercambiando información). Los resultados muestran que para todos los casos analizados se obtiene la distancia recorrida más corta cuando los planificadores de ruta trabajan como un equipo colaborativo
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