1,720,998 research outputs found
Identificación, caracterización y dinámica de las geoformas glaciales y periglaciales en la Cordillera de los Andes a través de sensores remotos
Full text linkTesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Falaschi, Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin
Rock Glaciers in the Patagonian Andes: An Inventory for the Monte San Lorenzo (Cerro Cochrane) Massif, 47° S
Full text linkAlthough rock glaciers in the Central and Desert Andes of Argentina and Chile have been previously studied in detail, much less attention has been paid to the occurrence of these permafrost forms in Patagonia. Recently, however, the establishment of the Argentinean Glacier Inventory program, which intends to inventory and monitor all ice masses along the Argentinean Andes, has started a large amount of new geocryological research. The project is designed to provide reliable and worldwide comparable results, supported by well established technical procedures and background information. Presented here is the first rock glacier inventory of the Monte San Lorenzo (Cerro Cochrane) region in the southern Patagonian Andes. A total of 130 intact (9.86 km2) and 47 fossil (1.45 km2) landforms were inventoried using two 2.5 m resolution ALOS Panchromatic Remote-sensing Instruments for Stereo Mapping images. Since the Argentinean federal initiative described above legally protects all rock glaciers in the country as water reserves, and due to the little scientific knowledge concerning rock glaciers in the vast majority of the Patagonian Andes, this inventory provides an important basis for political decision-making and opens further geocryological research avenues for the Patagonian region in general.Fil: Falaschi, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Tadono, Takeo. Japan Aerospace Exploration Agency; JapónFil: Masiokas, Mariano Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin
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
ALOS-derived glacier and rock glacier inventory of the Volcán Domuyo region (~36° S), southernmost Central Andes, Argentina
Full text linkIn this study we use optical ALOS AVNIR-2 and PRISM satellite images to map and inventory glaciers as well as active, inactive and fossil rock glaciers in the Volcán Domuyo region (36°16' S-36°54' S), located in the northwestern tip of the Neuquén Province in Argentina. The area is termed "Transition Cordillera" since it lies between the southernmost reaches of the Central Andes and the Patagonian Andes. We inventoried a total of 106 glaciers, covering an area of ~25.4 km2, and 173 intact rock glaciers (~11.3 km2) in the year 2009. Using a 1990 Landsat scene from this area, we estimated a retreat rate of 26% reduction (~1.4% per year) of the glacier covered area between 1990 and 2009. The minimum elevation of the front talus of active rock glaciers indicates that the lower limit of discontinuous mountain permafrost in the region is located around 2800 m a.s.l. The results here provide new information about the current extent and recent behavior of glaciers and the spatial distribution of mountain permafrost in this poorly known region of the southern Andes. The lack of complete, long climate records in the area precludes detailed analyses of the recent response of glaciers to climate variability. However, regional warming trends and a recent reduction in winter precipitation may have contributed to the observed recent glacier wastage in the Domuyo region.Fil: Falaschi, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Masiokas, Mariano Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Tadono, Takeo. Japan Aerospace Exploration Agency; JapónFil: Couvreux, Fleur. Météo-France; Franci
TIFF images of rock glacier surface velocities for Valley Calchaquíes region, Salta Province, Argentina
No full textFor the Valles Calchaquíes region, Northwestern Argentina, we derived rock glacier surface velocities (in unit m/a) from multi-temporal aerial and satellite imagery using a feature tracking approch. The data covers three epochs (EPs), EP1 from 1968 to 2009, EP2 from 2009/2010 to 2020, EP3 from 2020 to 2023. Given the variable availablility of aerial and satellite images, the spatial coverage is not the same for all three EPs and the limit of detection is spatially variable. For our analysis, we used rock glacier outlines as published by the Inventario Nacional de Glaciares of Argentina (https://www.glaciaresargentinos.gob.ar/; polygon data can be downloaded there) that have a minimum area of 0.02 km². We provide seperate data sets, one per epoch containing all derived average rock glacier velocities (unit m/a), and one only containing rock glacier velocities that exceed the limit of detection (unit m/a) of our analysis (see publication for details). While the data containing all derived average velocities is intended to document where feature tracking was performed, the data containing rock glacier velocities exceeding the limit of detection shall be used for analysis
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