1,720,957 research outputs found
Caracterización de las curvas de presión, par y potencia de un motor de combustión interna monocilíndrico bajo diferentes regímentes de operación
Get PDFDebido a que es importante conocer el comportamiento de ciertos parámetros de los motores de combustión interna de encendido provocado, funcionando bajo diferentes regímenes de operación, se hace necesario encontrar métodos para construir curvas representativas que caractericen dicho comportamiento. La presente investigación tiene como objetivo caracterizar las curvas de presión, potencia, par y consumo de un motor monocilíndrico funcionando con gasolina extra y corriente bajo diferentes condiciones de velocidad y carga. Dicho objetivo se logra mediante el análisis de señales experimentales con base en técnicas estadísticas y de tratamiento de datos. Inicialmente, se revisan conceptos teóricos generales sobre los motores de combustión interna y sus curvas más representativas, así como conceptos relacionados con el preprocesamiento y procesamiento de señales digitales y técnicas estadísticas para la recopilación, organización, análisis y presentación de datos. Se estudian las diferentes técnicas de diseño de experimentos y se selecciona la más adecuada para la realización del proyecto de investigación. Se instrumenta el motor y se adquieren las señales necesarias para el análisis requerido. Por medio de técnicas tales como, normalización, segmentación y tratamiento de señales, se procesan los datos y finalmente, mediante su análisis se procede a la construcción de las curvas de presión, potencia, par y consumo con base en procesos estadísticos y matemáticos
Diseño de un generador eólico de eje vertical de baja potencia
No full textEn este trabajo, el análisis y diseño de un aerogenerador de eje vertical tipo Savonius es desarrollado y planteado como un método para aprovechar el potencial eólico de la Universidad Tecnológica de Pereira, donde se propone ubicar el dispositivo. El generador eólico estará compuesto por dos módulos, cada uno de ellos integrado por dos álabes de perfil semicircular y estará encargado de convertir la energía eólica a energía mecánica, y posteriormente, mediante un generador eléctrico, se entregará la energía suficiente para cargar una batería de 12V, la cual puede ser utilizada en dispositivos tales como UPS, equipos médicos y de comunicación, entre otros. Para realizar el diseño del sistema eólico, se seleccionarán los elementos que van a comprender la unidad de generación y se validarán cada uno de los componentes (el rotor, el árbol y la estructura de soporte), por medio del software CAD SolidWorks, verificando su resistencia estática, dinámica, de rigidez y vibraciones. El objetivo principal de éste trabajo, es presentar un estudio que muestre las dimensiones necesarias de un aerogenerador tipo Savonius que permita cargar una batería comercial, bajo las condiciones del potencial eólico de la Universidad Tecnológica de Pereira.In this work, the analysis and the design of a vertical axis wind turbine Savonius type is developed a proposed as a way to exploit the wind potential Disponible en at the Universidad Tecnológica de Pereira. Where is planned to locate the device. The wind turbine will be composed by two modules which are integrated by two semicylindrical blades. The wind turbine will be on charge to convert the wind energy to
mechanical energy. After that, by an electric generator, the energy will be delivered to charge a 12V battery which can be used in devices like UPS, medical and communication equipment and others. To make the wind system design, the elements to compose the generation unit will be selected and each of the components will be validated (the rotor, the shaft and the support structure) verifying
its static, dynamic, rigidity and vibrations resistance by the SolidWorks software. The
principal objective of this paper is to present a study that shows the necessary dimensions of a wind turbine Savonius type that allows to charge a commercial battery under the wind potential conditions at Universidad Tecnológica de Pereira
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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