1,720,965 research outputs found
El Niño y crecidas anuales en los ríos del norte del Perú
No full textAbstract
The maximum annual floods which occur in the water courses of the north of Peru between 3° and 10° south, adapt well to a composite Gumbel distribution. The flow of these water courses which shows a big inter annual variability complys with 3 ocean-atmospheric conditions:
— The years when water is abnormally hot (situations “El Niño”) and when there are exceptional rains which develop catastrophic floods.
— The years when water is very cold and the rainfall very light (situations anti-“El Niño”).
— Finally the years of normal summer rains and normal oceanic conditions.
The parameters of the model reveal a strong regional disparity in the extension and the intensity of the catastrophic floods at the time of each of the above mentioned ocean-atmospheric conditions.Résumé
Les crues maximales annuelles qui se produisent dans les cours d’eau du nord du Pérou entre les 3° et 10°S s’ajustent bien à une distribution de Gumbel mixte à trois composantes. Le débit de ces cours d’eau, qui montre une grande variabilité interannuelle, obéit à trois conditions océano-atmosphériques où se retrouvent : les années d’eaux anormalement chaudes (situations “El Niño”) et de pluies exceptionnelles qui engendrent des crues catastrophiques ; les années d’eaux très froides et de très faible pluviosité (situations anti-“El Niño”) ; enfin les années de pluies d’été et de conditions océaniques normales. Les paramètres du modèle révèlent une forte disparité régionale dans l’extension et l’intensité des crues catastrophiques lors de chacune des conditions océano-atmosphériques mentionnées.Resumen
Las crecidas máximas anuales que tienen lugar en los ríos del norte del Perú, entre latitudes 3° y 10°S, se ajustan bien a un modelo planteado por una distribución Gumbel mixta basada en tres componentes. Esos ríos muestran una gran variedad interanual de caudal y sus cambios de descarga obedecen a tres condiciones oceánico-atmosféricas: años de aguas cálidas excepcionales (“El Niño”) y de alta pluviosidad que producen crecidas catastróficas; años de aguas frías excepcionales y de muy baja pluviosidad (anti-“El Niño”); años en los cuales tienen lugar lluvias estivales normales sin que se detecten condiciones oceánicas anómalas. Los parámetros del modelo revelan una fuerte espacialidad en lo referente a la severidad y la extensión de las crecidas catastróficas durante cada una de las condiciones oceánico-atmosféricas mencionadas.Caviedes César N., Waylen Peter R. El Niño y crecidas anuales en los ríos del norte del Perú. In: Bulletin de l'Institut Français d'Études Andines, tome 16, N°1-2, 1987. pp. 1-19
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
Respuestas del clima de América del Sur a las fases de ENSO
No full textSouth America climatic response to ENSO phases
The high phases of ENSO, El Niño (EN), and the low phases, Anti-Niño (AN) relate differently with the precipitation regimes of South America. In order to establish the character of these relations the annual precipitation totals have been analysed with a probabilistic approach corresponding to three sub-populations: totals of EN, totals of AN, and totals of the rest of the years, or “normal” years. Preceeding southern summers with EN, precipitation in Central Chile and Andean Argentina is above average. During particularly strong EN events in the tropical Pacific, droughts affect Northeast Brazil during the summers and falls preceeding EN. From December to March of EN years, it rains copiously along the west coast of South America between the Bay of Tumaco and Pacasmayo. In the interior of the Sierra and the Peruvian/Bolivian Altiplano droughts occur during the same period. In the Bolivian lowlands, Paraguay, south-eastern Brazilian rains are abnormally high during the southern summer and fall. In mid fall, abundant rains occur in the Rio de la Plata lowlands and in southern Brazil. The northern segment and lower basin of the Amazon experience less rains during EN and higher pluviosity during AN. The interior Amazon basin tends to react inversely as it experiences higher totals during some extraordinary EN events. Over Venezuela and Colombia under the influence of the Caribbean and North Atlantic rains during EN years are lower than normal but high during AN. Some regions of the Pampa and Patagonia do not react to EN impulses. Also independent is the behaviour of rains along the central part of Brazil. Precipitation during years termed as “normal” suggest an independence of the rain-generating mechanisms from the extreme phases of ENSO, and impose the study of anomalous precipitation associated to other tropical circulation fluctuations.Réponse du climat de l’Amérique du sud aux phases de l’ENSO
Les phases hautes de l'ENSO, El Niño (EN), ou basses, Anti-Niño (AN), ont des répercussions diverses sur la pluviométrie de l’Amérique du sud. Pour caractériser ces diverses réponses, les précipitations annuelles ou saisonnières ont été réunies en trois groupes : celui des années EN, celui des années AN et celui des années normales. Les années qui précèdent les étés australs avec EN, les pluies hivernales dans le centre du Chili et dans les Andes de l’ouest de l’Argentine sont renforcées. Certaines années, on observe des sécheresses dans le Nordeste du Brésil au cours de l’été et de l’automne austral qui précèdent le phénomène El Niño dans le Pacifique Tropical. Au cours des mois de décembre à mars des années EN, il pleut abondamment sur la côte ouest de l’Amérique du Sud, depuis la baie de Tumaco jusqu’à Pacasmayo. À l’intérieur, dans la Sierra et 1’Altiplano péruano-bolivien, on observe des sécheresses au cours de cette période alors qu’il pleut abondamment au cours de l’été et de l’automne austral dans les basses terres de l’Est de la Bolivie, du Paraguay et du Sud-Est du Brésil. À mesure que l’on s’avance vers l’automne austral, on observe de fortes précipitations dans la partie basse du bassin du Rio de la Plata et du Sud du Brésil. Dans la partie septentrionale et la partie inférieure du bassin amazonien les pluies sont déficitaires au cours des EN, pour devenir excédentaires au cours des AN. La partie intérieure du bassin amazonien réagit de manière inverse : on y observe des excès pluviométriques certaines années EN. Les régions du Vénézuela et de la Colombie, sous l'influence climatique des Caraïbes et de l’Atlantique présentent des anomalies négatives de précipitation au cours des EN et une forte pluviosité au cours des AN. Une partie de la Pampa et de la Patagonie ne réagit pas aux impulsions de El Niño. Les régions du centre du Brésil semblent aussi ne pas dépendre du phénomène.
Durant les années classées comme normales, on n’observe pas de dépendance des contrôles climatiques qui agissent au cours des phases extrêmes de l’Oscillation du Sud. Ceci montre que l’on doit approfondir l’étude des autres causes de variation de la circulation tropicale responsables des anomalies de précipitation.Las fases altas de ENSO, El Niño (EN), y las fases bajas, Anti-Niño (AN), se relacionan diferentemente con los regímenes de lluvias en América del Sur. Para establecer el carácter de estas relaciones, se ha analizado la precipitación anual de estaciones típicas, considerando tres subpoblaciones: totales anuales de años EN, totales de años AN, y el resto o años “normales”. Precediendo a veranos australes con fenómenos EN, la precipitación invernal en Chile Central y los Andes de Argentina es abundante. Durante los veranos con episodios EN en el Pacífico tropical, suelen afectar sequías el Noreste de Brasil especialmente en el otoño o verano precedente. De diciembre a marzo de años EN, llueve copiosamente a lo largo de la costa oeste de America del Sur comprendida entre la Bahía de Tumaco y Pacasmayo. En el interior de la Sierra y el Altiplano peruano-boliviano tienen lugar sequías. En las tierras bajas de Bolivia, Paraguay y el sureste de Brasil hay fuertes lluvias anormales durante el verano y otoño austral. En medio del otoño hay precipitaciones intensas en las tierras bajas del Río de la Plata y el sur de Brasil. El segmento norte y la cuenca inferior del Amazonas tienen menos pluviosidad durante EN y niveles mayores durante AN. La cuenca interior del Amazonas reacciona inversamente, ya que tiene pluviosidad excesiva durante algunos EN. Las regiones de Venezuela y Colombia bajo la influencia del Caribe y el Atlántico experimentan anomalías negativas de lluvias durante EN y alta pluviosidad en AN. Algunas regiones de la Pampa y Patagonia no reaccionan a los impulsos de EN. Las lluvias en el centro de Brasil son independientes también de las fases de ENOS. Las precipitaciones durante los llamados años “normales” sugieren que existe una independencia con respecto a los mecanismos generadores de lluvias condicionados por las fases extremas de ENOS, hecho que reclama una mejor investigación de otras fluctuaciones de la circulación tropical que condicionan anomalías de precipitación.Caviedes César N., Waylen Peter R. Respuestas del clima de América del Sur a las fases de ENSO. In: Bulletin de l'Institut Français d'Études Andines, tome 27, N°3, 1998. Variations climatiques et ressources en eau en Amérique du Sud. Importance et conséquences des événements El Niño. pp. 613-626
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
- …
