1,721,199 research outputs found
Cuantificación de los efectos del cambio climático sobre el régimen medio y extremal del nivel de mar en la costa uruguaya
Full text linkEl cambio climático es un foco de estudio importante en la actualidad debido a las consecuencias ambientales, sociales, económicas y demás que el mismo está generando. Una de las importantes consecuencias es el cambio generado en la dinámica de aguas tanto oceánicas como continentales, y en particular, el aumento del nivel del mar. El objetivo principal de este trabajo de tesis es cuantificar los cambios en el nivel de mar a lo largo de la costa uruguaya, analizando también el origen de estos cambios. Con el fin de lograr dicho objetivo se hace uso de las proyecciones de vientos y presiones de los modelos climáticos globales correspondientes a la fase 5 del proyecto de intercomparación de modelos acoplados (CMIP5, Coupled Model Intercomparison Project Phase 5).
A lo largo de la costa uruguaya las componentes meteorológicas y astronómicas tienen relevancia equivalente sobre el nivel de mar total, por lo cual para analizar los cambios en el mismo es necesario considerar posibles cambios en los forzantes atmosféricos. Por otra parte, las características del estuario del Río de la Plata, como sus grandes dimensiones y bajas profundidades, hacen que las interacciones no lineales que puedan surgir entre el aumento del nivel medio del mar y la marea astronómica y meteorológica pueden ser importantes. Debido a lo anterior, para lograr el objetivo se adopta un esquema de downscaling dinámico mediante modelos anidados, denominados en el trabajo de tesis modelo regional y modelo local, teniendo como punto de partida dos modelos hidrodinámicos de nivel de mar previamente implementados en el IMFIA ((Martínez et al. 2015; IMFIA, 2018a)). El modelo regional es la implementación en su versión 2D del modelo numérico MOHID a un dominio que comprende al Océano Atlántico Sur y es forzado por ondas de marea astronómica en bordes oceánicos, caudal medio de los ríos Paraná y Uruguay y por vientos y presiones en la superficie libre. El modelo local es la implementación en su versión 2D del modelo TELEMAC a un dominio que abarca el Río de la Plata y su Frente Marítimo y es forzado por vientos y presiones en la superficie libre, caudales medios de los ríos Paraná, Uruguay y Santa Lucía y la condición de borde del modelo regional en las fronteras abiertas.
Previo a forzar los modelos hidrodinámicos se evalúan 7 modelos atmosféricos basándose en la metodología desarrollada por Pérez et al. (2014): ACCESS1.0, CMCC-CM, CNRM-CM5, MIROC5, IPSL-CM5A-MR y HadGEM2-ES. La evaluación se basa en la clasificación de campos de presión de reanálisis (NCEP-CFSR) en 100 tipos de tiempo, también denominados como campos sinópticos de presión, calculando su probabilidad de ocurrencia a lo largo del período comprendido entre 1985-2005. Luego se comparan las probabilidades de ocurrencia de los tipos de tiempo para el reanálisis y para cada uno de los modelos atmosféricos globales. La evaluación indicó que el modelo MIROC5 es el que mejor representa las situaciones sinópticas de presión más probables y menos probables al igual que la variabilidad interanual de las probabilidades de ocurrencia.
Las simulaciones de nivel de mar se realizaron para tres horizontes temporales: histórico (1985-2005), corto plazo (2027-2045) y largo plazo (2082-2100); y para dos escenarios: RCP 4.5 y RCP 8.5. Al comparar los resultados del modelo local durante el período histórico forzado con vientos y presiones de los modelos atmosféricos globales con las del modelo local forzado con vientos de reanálisis se concluyó que la metodología de evaluación era acertada, obteniéndose que los modelos que mejor representan la climatología de niveles en el dominio de estudio son MIROC5 y CMCC-CM.
Las simulaciones de los bloques futuros se realizaron imponiendo en ambos modelos el aumento del nivel medio del mar correspondiente a cada año. Al analizar el cambio en la media del nivel de mar total a lo largo de la costa se observó que el cambio es básicamente constante a lo largo de la misma y está principalmente dominado por el aumento en el nivel medio del mar. Por otra parte al analizar el cambio a lo largo de la costa en el cuantil 99% a largo plazo el mismo presentó un máximo en la zona interior del estuario y alrededor de Montevideo. Analizando el cambio en el cuantil 99% de la componente meteorológica se determinó que el cambio es muy pequeño a lo largo de la costa y no contribuye a la distribución espacial observada en el cambio del nivel de mar total. Por otra parte, los cambios en las amplitudes de las componentes M2 y O1 de la marea astronómica a lo largo de la costa muestran una distribución no constante a lo largo de la misma que además es muy similar para cualquiera de los forzantes atmosféricos, concluyéndose que solo dependen del escenario RCP y el horizonte temporal.
Del trabajo realizado se concluye que la principal componente del cambio en el nivel de mar es el aumento del nivel medio del mar, siguiéndole el efecto que este aumento tiene sobre la marea astronómica. Lo anterior indica que la metodología de downscaling dinámico aplicada es la correcta y necesaria para poder determinar el cambio en el nivel de mar debido a que las interacciones entre la marea astronómica y el nivel medio del mar cobran especial relevancia en la zona de estudio. El cambio en la media de nivel de mar total a largo plazo y para el escenario más severo RCP 8.5 es de 61 cm, mientras que el aumento en el cuantil 99% a largo plazo para el escenario más severo RCP 8.5 alcanza los 74 cm en la zona costera desde Colonia hacia el interior del estuario y los 71 cm en la zona costera de Montevideo
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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