1,720,954 research outputs found
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
Morphometric analysis to support the assessment of tectonic influence on topographic rejuvenation in the Prata River basin, northern western edge of the Paraná Sedimentary Basin
No full textAbordagens morfométricas adotadas em estudos em ambientes de domínio intraplaca, como a intraplaca brasileira, caracterizados por baixa amplitude tectônica, têm evidenciado a natureza transiente ou o rejuvenescimento destas paisagens, cujo desequilíbrio tem sido comumente associado a variações climáticas e/ou litológicas. No entanto, a influência da tectônica de baixa magnitude no desenvolvimento dos relevos nesses ambientes ainda é pouco compreendida. O objetivo deste estudo foi investigar a geomorfologia de uma porção da borda ocidental norte da Bacia Sedimentar do Paraná com o intuito de reconhecer evidências de influência tectônica. Métricas topográficas, como a análise do perfil longitudinal da drenagem, têm sido eficazes na identificação de perturbações tectônicas, mesmo em regiões intraplaca. A metodologia empregada fundamentou-se na análise integrada de métricas topográficas, tais como perfis longitudinais de drenagem, knickpoints e o índice de inclinação do canal (ksn), juntamente com propriedades morfométricas adequadas para identificação de indicadores tectônicos, incluindo lineamentos morfoestruturais, assimetria de bacia de drenagem, análise do padrão e anomalias de drenagem. A análise dos perfis longitudinais e métricas derivadas revelou uma maior incidência de knickpoints de slope break e vertical step, juntamente com valores mais elevados de ksn nas transições entre as áreas elevadas e rebaixadas. Esses indicadores corroboram a hipótese de influência tectônica no desenvolvimento da paisagem e evidenciam o estado transiente da área de estudo. O mapeamento dos lineamentos morfoestruturais mostrou direções principais N70-80E e N60-70E, consistentes com grandes descontinuidades crustais magnéticas. A presença de sismos alinhados com essas estruturas fortalece a hipótese de que os lineamentos resultam da reativação de fraturas e/ou falhas do embasamento. A análise de drenagem revelou um padrão geometrizado da rede drenagem, evidenciando controle estrutural nos traçados dos canais. Já a análise de fatores de assimetria de drenagem indicou assimetria com direções de basculamentos, em geral, ortogonais a estruturas NE e NW. Os resultados obtidos neste estudo reforçam a suposição da contribuição de estruturas de origem tectônica no rejuvenescimento topográfico. O principal mecanismo tectônico atribui-se às forças compressivas resultantes da interação da deriva da Placa Sul-Americana com a Placa de Nazca, especialmente a terceira fase orogenética da Cadeia Andina, a fase Quéchua. Essas tensões resultaram na elevação e, consequentemente, desencadearam fenômenos tectônicos e/ou reativação de zonas de fraqueza preexistentes.Morphometric approaches adopted in studies in intraplate domain environments, such as the Brazilian intraplate, characterized by low tectonic amplitude, have highlighted the transient nature or rejuvenation of these landscapes, whose imbalance has been commonly associated with climatic and/or lithological variations. However, the influence of low-magnitude tectonics on the development of reliefs in these environments is still poorly understood. The objective of this study was to investigate the geomorphology of a portion of the western edge of the northern Paraná Sedimentary Basin in order to recognize evidence of tectonic influence. Topographic metrics, such as longitudinal drainage profile analysis, have been effective in identifying tectonic disturbances, even in intraplate regions. The methodology used was based on the integrated analysis of topographic metrics, such as longitudinal drainage profiles, knickpoints and the channel steepness index (ksn), together with morphometric properties suitable for identifying tectonic indicators, including morphostructural lineaments, asymmetry of drainage basin, analysis of drainage patterns, and anomalies. Analysis of the longitudinal profiles and derived metrics revealed a higher incidence of slope break and vertical step knickpoints, along with higher ksn values in the transitions between elevated and depressed areas. These indicators corroborate the hypothesis of tectonic influence on the development of the landscape and highlight the transient state of the study area. Mapping of the morphostructural lineaments showed main directions N70-80E and N60-70E, consistent with large magnetic crustal discontinuities. The presence of earthquakes aligned with these structures strengthens the hypothesis that the lineaments result from the reactivation of fractures and/or basement faults. Drainage analysis revealed a geometric pattern of the drainage network, demonstrating structural control in the channel layouts. The analysis of drainage asymmetry factors indicated asymmetry with tipping directions, generally orthogonal to NE and NW structures. The results obtained in this study reinforce the assumption of the contribution of structures of tectonic origin to topographic rejuvenation. The main tectonic mechanism is attributed to the compressive forces resulting from the interaction of the drift of the South American Plate with the Nazca Plate, especially the third orogenic phase of the Andean Chain, the Quechua phase. These tensions resulted in elevation and, consequently, triggered tectonic phenomena and/or reactivation of pre-existing zones of weakness.Outr
ANÁLISE TEXTURAL E CLASSIFICAÇÃO DIGITAL DE IMAGENS SAR PARA DISCRIMINAÇÃO DE ALVOS AGRÍCOLAS: Texture analysis and digital classification of SAR images for agricultural target discrimination
Get PDFThe remote sensing images of the visible and infrared range of the electromagnetic spectrum have great potential for discriminating agricultural areas for the purpose of estimating the yield. Nevertheless, the presence of clouds prevents the acquisition of this type of images, however, the SAR images are independent of meteorological conditions. In this context, this work verified the potential of two SAR/Radarsat-1 images, C band, HH polarization, in Fine-5/upward (F5A) and Standard-7/downward (S7D) modes in the discrimination of agricultural targets in the region of Assis-SP. The methods were based on visual analyzes and on the comparison of the digital classifications of the original and filtered F5A and S7D images, as well as their texture measurements. The results indicated that the filtered images improved the discrimination of the targets in relation to the original images, with the Gamma adaptive filter being the most efficient among the other tested filters. Texture image classifications were generally better than filtered image classifications, indicating that texture measures can be useful attributes to maximize discrimination of agricultural targets. The classes with the greatest discrimination potential in both F5A and S7D images, with accuracy above 50%, were: water, urban area, sugarcane-2, soy and exposed soil-1.Las imágenes de teledetección del rango visible e infrarrojo del espectro electromagnético tienen un gran potencial para discriminar áreas agrícolas con el fin de estimar el rendimiento. Sin embargo, la presencia de nubes impide la adquisición de este tipo de imágenes, sin embargo, las imágenes SAR son independientes de las condiciones meteorológicas. En este contexto, este trabajo verificó el potencial de dos imágenes SAR/Radarsat-1, banda C, polarización HH, en modos Fine-5/hacia arriba (F5A) y Standard-7/hacia abajo (S7D) en la discriminación de objetivos agrícolas. en la región de Assis-SP. Los métodos se basaron en análisis visuales y en la comparación de las clasificaciones digitales de las imágenes originales F5A y S7D, filtradas y sus medidas de textura. Los resultados indicaron que las imágenes filtradas mejoraron la discriminación de objetivos en relación con las imágenes originales, siendo el filtro adaptativo Gamma el más eficiente entre los otros filtros probados. Las clasificaciones de imágenes de textura fueron generalmente mejores que las clasificaciones de imágenes filtradas, lo que indica que las medidas de textura pueden ser atributos útiles para maximizar la discriminación de objetivos agrícolas. Las clases con mayor potencial de discriminación tanto en las imágenes F5A como S7D, con una precisión superior al 50%, fueron: agua, zona urbana, caña de azúcar-2, soja y suelo expuesto-1.RESUMO - As imagens de sensoriamento remoto da faixa do visível e infravermelho do espectro eletromagnético apresentam grande potencial na discriminação de áreas agrícolas para fins de estimativa de safra. Contudo, a presença de nuvens impede a aquisição deste tipo de imagens, porém, as imagens SAR independem de condições meteorológicas. Neste contexto, este trabalho verificou o potencial de duas imagens SAR/Radarsat-1, banda C, polarização HH, nos modos Fine-5/ascendente (F5A) e Standard-7/descendente (S7D) na discriminação de alvos agrícolas na região de Assis-SP. Os métodos se basearam em análises visuais e na comparação das classificações digitais das imagens F5A e S7D originais, filtradas e medidas de textura destas. Os resultados indicaram que as imagens filtradas melhoraram a discriminação dos alvos em relação às imagens originais, sendo o filtro adaptativo Gamma, o mais eficiente entre os outros filtros testados. As classificações das imagens de textura foram, em geral, melhores do que as classificações das imagens filtradas, indicando que as medidas de textura podem ser atributos úteis para maximizar a discriminação de alvos agrícolas. As classes com maior potencial de discriminação em ambas as imagens F5A e S7D, com exatidão acima de 50%, foram: água, área urbana, cana-de-açúcar-2, soja e solo exposto-1.
Palavras-chave: Radarsat-1. Máxima Verossimilhança (MAXVER). Filtros adaptativos. Sensoriamento remoto. Alvos agrícolas.
ABSTRACT - The remote sensing images of the visible and infrared range of the electromagnetic spectrum have great potential for discriminating agricultural areas for the purpose of estimating the yield. Nevertheless, the presence of clouds prevents the acquisition of this type of images, however, the SAR images are independent of meteorological conditions. In this context, this work verified the potential of two SAR/Radarsat-1 images, C band, HH polarization, in Fine-5/ascending (F5A) and Standard-7/descending (S7D) modes in the discrimination of agricultural targets in the region of Assis-SP. The methods were based on visual analyzes and on the comparison of the digital classifications of the original and filtered F5A and S7D images, as well as their texture measurements. The results indicated that the filtered images improved the discrimination of the targets in relation to the original images, with the Gamma adaptive filter being the most efficient among the other tested filters. Texture image classifications were generally better than filtered image classifications, indicating that texture measures can be useful attributes to maximize discrimination of agricultural targets. The classes with the greatest discrimination potential in both F5A and S7D images, with accuracy above 50%, were: water, urban area, sugarcane-2, soy and exposed soil-1.
Keywords: Radarsat-1. Maximum Likelihood (MAXVER). Adaptive filters. Remote sensing. Agricultural targets
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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