1,721,066 research outputs found
Luigi Balzan : des Andes à l'Amazonie 1891-1893 : voyage d'un jeune naturaliste au temps du caoutchouc
No full textLuigi Balzan : des Andes à l'Amazonie 1891-1893 : voyage d'un jeune naturaliste au temps du caoutchouc
No full textRapport I.9. : Extension des surfaces agricoles et modification de l'écoulement. Analyse sur deux bassins de la savane africaine
No full textSoil surfaces and flow modifications have been studied since 1960 on two dry savannah small watersheds. These last are both caracterised by an important increase of cultivated areas. All the study stages use the simulated rainfall data collected on 19 plots (1m2) in the 80's. In Korhogo-Waraniéné (Ivory Coast), surface runoffs and base flows decreased between 1962-67 and 1968-72. During the 80's, this trend is not reversed. In Kogneré-Boulsa (Burkina Faso, previously Upper-Volta) , the surface runoffs were multiplied by two between the 60 's and the 80 's while the annual rainfall decreased. The part played by agricultural techniques is set up to explain these different results. Intensive mixed farming is done in Korhogo-Waraniéné by traditional methods. Contiguous heads rows are cut off by deep and irregular furrows. Upkeep never stops all year long preserving a good surfacial soil porosity. After a quick weeding, an extensive millet crop is sowed in Kogneré-Boulsa. Between the heads, bare soil surfaces are susceptible to erosion. In some areas, the landscape becomes a Sahelian thorny scrub .Les modifications des états de surface et des baromètres de l'écoulement sous l'impact de l'accroissement de l'emprise anthropique sont étudiées à partir de 1960. A chaque stade du travail, les acquis de la simulation de pluie sur parcelles sont utilisés. Des résultats divergents sont obtenus : diminution de la lame de base et de celle ruisselées à Korhogo-Waraniéné et augmentation très forte de la lame ruisselée à Kogneré-Boulsa. Le rôle des pratiques culturales très différentes est avancé pour expliquer ces divergences à l'échelle des bassins. L'agriculture très intensive, avec billonnage manuel, de Korhogo-Waraniéné favorise l'infiltration à l'inverse des semis de mil très espacés de Kogneré-Boulsa où la dégradation structurale est favorisée.Albergel Jean, Gioda Alain. Rapport I.9. : Extension des surfaces agricoles et modification de l'écoulement. Analyse sur deux bassins de la savane africaine. In: L'impact des activités humaines sur les eaux continentales. Dix neuvièmes journées de l'hydraulique, Paris 9-11 septembre 1986. Tome 1, 1986
Rapport IV. 9 : Crues et aménagements des lits depuis le XIXe siècle dans la plaine du Pô au sud de Turin
No full textSince 1801, there has been very little development of the river beds in the Upper Po Plain (south of Torino -Italy). This lack of development is an important factor for its use in the whole Po catchment. It is a natural retention and settling basin during floods.
Actual problems which are partly resolved come from flood-plain development and the over-exploitation of sand and gravel in the bed layers. Others problems are a limited budget and overlapping administrative responsibilities.
from 1978-88 a flood warning service will be set up. The Author proposes to extend this service by the addition of real-time hydrometeorological forecasting.L'héritage de l'aménagement est caractérisé par la faiblesse des travaux d'hydraulique. Cette faiblesse est nécessaire pour conserver le rôle d'écrêtement et de décantation des eaux attribué à la haute Plaine du Pô, lors des crues. Les limites actuelles de l'aménagement, en partie en voie de résolution, découlent de la valorisation croissante de la plaine d'inondation et de la sur-exploitation des matériaux des lits. S'y ajoutent des limites financières et des problèmes d'éparpillement des compétences administratives.
Le futur proche bénéficiera d'un système d'annonces de crue, en cours d'installation, que l'Auteur voudrait compléter par la prévision hydrométéorologique en temps réel.Gioda Alain. Rapport IV. 9 : Crues et aménagements des lits depuis le XIXe siècle dans la plaine du Pô au sud de Turin. In: L'impact des activités humaines sur les eaux continentales. Dix neuvièmes journées de l'hydraulique - Question I, II, III, IV, V et Compte rendu des séances. Tome 4, 1986
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
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