1,721,231 research outputs found
Land-cover classification in the Brazilian Amazon with the integration of Landsat ETM + and Radarsat data.
Get PDFLand-cover classification with remotely sensed data in moist tropical regions in a challenge due to the complex biophysical conditions. This paper explores techniques to improve land-cover classification accuracy through a comparative analysis of different combinations of spectral signatures and textures from Landsat Enhanced Thematic Mapper Plus (ETM +) and Radarsat data. A wavelet-merging technique was used to integrate Landsat ETM + multispectral and panchromatic data or Radarsat data. Grey-level co-occurrence matrix (GLCM) textures based on Landsat ETM + panchromatic of Radarsat data and different sizes of moving windows were examined. A maximum-likelihood classifier was used to implement image classification for different combinations. This research indicates the important role of textures in improving land-cover classification accuracies in Amazonian environments. ..
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
Correlation Of Spectral Variables And Aboveground Carbon Stock Of Agroforestry Systems [correlação De Variáveis Espectrais E Estoque De Carbono Da Biomassa Aérea De Sistemas Agroflorestais]
No full textThe objective of this work was to evaluate the correlation between spectral variables and aboveground carbon stock of agroforestry systems in the region of Tomé-Açu, PA, Brazil. Twenty-four vegetation indices from three groups (simple ratio, normalized difference, and complex), calculated from images of the TM/ Landsat-5 sensor acquired in 2008, were tested. The obtained variables were correlated, by means of simple linear regression, to carbon stock from four agroforestry systems with different ages and floristic composition. The correlations obtained among spectral variables and carbon stock were significant in 47% of the tested indices and changed according to the differences in biomass of the analyzed systems. The best correlations were obtained by the simple ratio and normalized difference indices in young agroforestry systems, and by complex vegetation indices in older agroforestry systems.47912611269de Accioly, L.J.O., Pachêco, A., Costa, T.C.C., Lopes, O.F., Oliveira de, M.A.J., Relações empíricas entre a estrutura da vegetação e dados do sensor TM/LANDSAT (2002) Revista Brasileira de Engenharia Agrícola e Ambiental, 6, pp. 492-498Baret, F., Guyot, G., Potentials and limits of vegetation indices for LAI and APAR assessment (1991) Remote Sensing of Environment, 3, pp. 161-173Bartelt, D., Koch, J., Tourinho, M.M., Anbau von Acai und Kakao in Primärwäldern der Varzeas am Rio Tocantins (Brasilien/ Para) (2000) Forstarchiv, 71, pp. 250-256Bolfe, E.L., Batistella, M., Análise florística e estrutural de sistemas silviagrícolas em Tomé-Açu Pará (2011) Pesquisa Agropecuária Brasileira, 46, pp. 1139-1147Bolfe, E.L., Ferreira, M.C., Batistella, M., Biomassa epígea e estoque de carbono de agroflorestas em Tomé-Açu PA (2009) Revista Brasileira de Agroecologia, 4, pp. 2171-2175Clevers, J.G.P.W., The derivation of a simplified reflectance model for the estimation of leaf area index (1988) Remote Sensing of Environment, 25, pp. 53-69Demattê, J.A.M., Nanni, M.R., Weathering sequence of soils developed from basalt as evaluated by laboratory (IRIS), airborne (AVIRIS) and orbital (TM) sensors (2003) International Journal Remote Sensing, 24, pp. 4715-4738Foddy, G.M., Boyd, D.S., Cluter, M.E.J., Predictive relations of tropical forest biomass from Landsat TM data and their transferability between regions (2003) Remote Sensing of Environment, 85, pp. 463-474Freitas, S.R., Mello, M.C.S., Cruz, C.B.M., Relationships between forest structure and vegetation indices in Atlantic Rainforest (2005) Forest Ecology and Management, 218, pp. 353-362Higuchi, N., Santos dos, J., Ribeiro, R.J., Minette, L., Biot, Y., Biomassa da parte aérea da vegetação de floresta tropical úmida de terra-firme da Amazônia Brasileira (1998) Acta Amazonica, 28, pp. 153-166Huete, A., Didan, K., Miura, T., Rodriguez, E.P., Gao, X., Ferreira, L.G., Overview of the radiometric and biophysical performance of the MODIS vegetation indices (2002) Remote Sensing of Environment, 83, pp. 195-213Huete, A.R., A soil-adjusted vegetation index (SAVI) (1988) Remote Sensing of Environment, 25, pp. 295-309(2008) Monitoramento da floresta amazônica brasileira por satélite, , www.dpi.inpe.br/prodesdigital, INSTITUTO NACIONAL DE PESQUISAS ESPACIAIS Disponível em Acesso em: 15 ago. 2011Jordan, C.F., Derivation of leaf-area index from quality of light on the forest floor (1969) Ecology, 50, pp. 663-666Liu, W.T., Kogan, F., Monitoring Brazilian soybean production using NOAA/AVHRR based vegetation condition indices (2002) International Journal of Remote Sensing, 23, pp. 1161-1179Lu, D., Mausel, P., Brondizio, E., Moran, E., Assessment of atmospheric correction methods for Landsat TM data applicable to Amazon basin LBA research (2002) International Journal of Remote Sensing, 23, pp. 2651-2671Lu, D.S., Batistella, M., Moran, E., Satellite estimation of aboveground biomass and impacts of forest stand structure (2005) Photogrammetric Engineering and Remote Sensing, 71, pp. 967-974Montagnini, F., Nair, P.K.R., Carbon sequestration: an underexploited environmental benefit of agroforestry systems (2004) Agroforestry Systems, 61, pp. 281-295(2008) The Landsat Program, , http://landsat.gsfc.nasa.gov/, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Accessed on: 25 Jan. 2009Nobre, C.A., Sampaio, G., Salazar, L., Mudanças climáticas e Amazônia (2007) Ciência e Cultura, 59, pp. 22-27Pachêco, N.A., Bastos, T.X., (2008) Boletim agrometeorológico 2006, p. 30. , Tomé-Açu, PA. Belém: Embrapa Amazônia Oriental, (Embrapa Amazônia Oriental. Documentos, 320)Perry, C.R., Lautenschlager, L.F., Functional equivalence of spectral vegetation indices (1984) Remote Sensing of Environment, 14, pp. 169-182Pinho, R.C., Miller, R.P., Alfaia, S.S., Agroforestry and the improvement of soil fertility: a view from Amazonia (2012) Applied and Environmental Soil Science, 2012, pp. 1-12. , Doi:10.1155/2012/616383Ponzoni, F.J., Rezende, A.C.P., Caracterização espectral de estágios sucessionais de vegetação secundária arbórea em Altamira (PA), através de dados orbitais (2004) Revista Árvore, 28, pp. 535-545Qi, J., Chehbouni, A., Huete, A.R., Kerr, Y.H., Sorooshian, S., A modified soil adjusted vegetation index (1994) Remote Sensing of Environment, 48, pp. 119-126Richardson, A.J., Wiegand, C.L., Distinguishing vegetation from soil background information (1977) Photogrammetric Engineering and Remote Sensing, 1, pp. 1541-1552Rizzi, R., Rudorff, B.F.T., Imagens do sensor MODIS associadas a um modelo agronômico para estimar a produtividade de soja (2007) Pesquisa Agropecuária Brasileira, 42, pp. 73-80Rodrigues, T.E., Santos dos, P.L., Rolim, P.A.M., Santos, E., Rego, R.S., da Silva, J.M.L., Valente, M.A., Gama, J.R.N.F., (2001) Caracterização e classificação dos solos do Município de Tome-Acu, Pará, p. 49. , Belém: Embrapa Amazônia Oriental, (Embrapa Amazônia Oriental. Documentos, 117)Rouse, J.W., Haas, R.H., Schell, J.A., Deering, D.W., Harlan, J.C., Monitoring the vernal advancement and retrogradation (greenwave effect) of natural vegetation, , Greenbelt: NASA, 1974. 371 (NASA/GSFC. Final report)Silleos, N.G., Alexandridis, T.K., Gitas, I.Z., Perakis, K., Vegetation indices: advances made in biomass estimation and vegetation monitoring in the last 30 years (2006) Geocarto International, 21, pp. 21-28de Tsukamoto, A.A., Couto, L., Neves, J.C.L., Passos, C.A.M., Silva, M.L., Fixação de carbono em um sistema agrissilvipastoril com eucalipto na região do cerrado de Minas Gerais (2004) Agrossilvicultura, 1, pp. 29-4
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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