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Registros recuperados: 28
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Análise da relação entre os perfis de NDVI obtidos dos sensores AVHRR/NOAA e MODIS nas áreas produtoras de cana-de-açúcar em São Paulo. Repositório Alice
GONÇALVES, R. R. do V.; ZULLO JUNIOR, J.; MARQUEZINI, O.; AMARAL, B. F. do; SOUSA, E. P. M. de; ROMANI, L. A. S..
Neste contexto, o objetivo do trabalho foi comparar dados de NDVI do AVHRR/NOAA e de NDVI do MODIS/TERRA em áreas produtivas de cana-de-açúcar no estado de São Paulo, no período de abril de 2001 a março de 2010.
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Sensoriamento remoto; Séries temporais; Agrupamento; Clustering; Remote sensing; Time series analysis; Cluster analysis.
Ano: 2013 URL: http://www.alice.cnptia.embrapa.br/handle/doc/961573
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Análise e mineração de dados de sensores orbitais para acompanhamento de safras de cana-de-açúcar. Repositório Alice
AMARAL, B. F.; CHINO, D. Y.; ROMANI, L. A. S.; GONÇALVES, R. R. V.; SOUSA, E. P. M. de; TRAINA, A. J. M..
Resumo. O impacto causado por eventos climáticos extremos em todo o mundo tem motivado pesquisas para redução de gases de efeito estufa. No Brasil, a cana-de-açúcar é a principal fonte para produção de etanol, como alternativa a combustíveis fósseis. Nesse contexto, dados de sensoriamento remoto têm sido utilizados para monitorar safras de cana-de-açúcar e apoiar pesquisas científicas. Neste trabalho, é proposta uma metodologia baseada em agrupamento de dados para analisar séries temporais de NDVI obtidas de satélites AVHRR/NOAA. Os experimentos mostram que a abordagem proposta permite identificar áreas com padrões de desenvolvimento similares, considerando também os diferentes ciclos de vida da cultura.
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Mineração de dados; Safras de cana-de-açúcar; Análise de séries temporais; Clusterização; Sugarcane; Time series analysis; Clustering.
Ano: 2011 URL: http://www.alice.cnptia.embrapa.br/handle/doc/898217
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APPLE IDENTIFICATION IN FIELD ENVIRONMENT WITH OVER THE ROW MACHINE VISION SYSTEM CIGR Journal
Silwal, Abhisesh; Gongal, Aleana; Karkee, Manoj.
Accurate detection and identification of fruits is critically important for the success of developing automated apple harvesting system. Research has been conducted to identify apples in orchard environment with reasonable accuracy when apples are clearly visible or partially occluded. However, only limited work has been carried out to identify fruit in clusters, which is critically important as fruit clusters are common in field conditions. This work focused on accurately identifying partially visible apples and apples in clusters using a machine vision system. An over the row platform with tunnel structure and artificial lighting was used to increase uniformity in imaging environment. Iterative Circular Hough Transform (CHT) was used to detect clearly...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Agricultural Engineering; Mechanization and Automation apple identification; Clustering; Circular Hough Transform; Blob analysis.
Ano: 2014 URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3006
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DIETARY EVOLUTION OVER TIME IN EUROPE, BETWEEN CYCLOPS AND PHAECIANS . AN OUTLOOK ON THE ROLE OF SUPPLY-SIDE FACTORS IN DRIVING CHANGES IN THE FOOD PATTERNS AgEcon
Finardi, Corrado; Arfini, Filippo; Turrini, Aida.
The present study intends to shed light, both from a descriptive and investigative point of view on the dietary evolution taking place in Europe during last 45 years, using secondary data from FAO FBS, which can cover the entire time span considered and allow for several extrapolation and timeseries analysis, differently than single survey data.. After a clustering of selected european national diets, using specific metrics with respect both to internal and external variety (as measured by appropriate indicators), we intended to check the actual distance that average, national diets have in front of the so called Food Pyramid, which consists in a balance of several food items in adequate proportions and in fact glorifies the healthy virtues of the...
Tipo: Conference Paper or Presentation Palavras-chave: Diets; Evolution; Clustering; Food pyramid; Europe; Trade; GI; Agricultural and Food Policy; Consumer/Household Economics; Demand and Price Analysis; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Health Economics and Policy; E37; Q18.
Ano: 2010 URL: http://purl.umn.edu/116443
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Distribution of annual rainfall in homogeneous regions through data mining techniques in southern Brazil. Repositório Alice
AVILA, A. M. H. de; FERREIRA JÚNIOR, D.; OLIVEIRA, S. R. M..
This study aimed to transform time series of annual data of precipitation of Rio Grande do Sul in homogeneous precipitation regions through clustering techniques (data mining).
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: Séries históricas; Precipitação; Técnica de agrupamento; Dados faltantes; Risco climático; Precipitation; Clustering; Climatic risk; Missing data; Time series analysis; Cluster analysis.
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1027267
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Does Knowledge-Based Economy Speaks to Consumers? A French Case Study with Respect to Food Products AgEcon
Giraud, Georges; Lebecque, Annick; Amblard, Corinne; Bord, Cecile; Sulmont-Rosse, Claire; Lefur, Yves.
The paradigm of knowledge-based economy states that information asymmetry between consumers and producers will be reduced thanks to information availability and dissemination through the Internet or other media channels. Conversely to this statement, some published articles shown that knowledge-based economy reinforces the information asymmetry between experts and novices among the consumers (Hogg et al., 2007; Gregan-Paxton & Roedder-John, 1997; Alba & Hutchinson, 1987). Accordingly, we will consider the non homogeneity of consumers and will try to identify and qualify the differences between several groups of respondents regarding two food items by means of a k-means clustering applied to a knowledge-oriented questionnaire.
Tipo: Conference Paper or Presentation Palavras-chave: Consumer Knowledge; Clustering; Wine; Cheese; France; Agribusiness; Agricultural and Food Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Industrial Organization.
Ano: 2008 URL: http://purl.umn.edu/49848
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Do-it-yourself shuffling and the number of runs under randomness AgEcon
Smeeton, Nigel; Cox, Nicholas J..
A common class of problem in statistical science is estimating, as a benchmark, the probability of some event under randomness. For example, in a sequence of events in which several outcomes are possible and the length of the sequence and number of outcomes of each type known, the number of runs gives an indication of whether the outcomes are random, clustered, or alternating. This note explains and illustrates a simple method of random shuffling that is often useful. We show how the conditional probability distribution of the number of runs may be derived easily in Stata, thus yielding p-values for testing the null hypothesis that the type of outcome is random. We also compare our direct approach with that using the simulate command.
Tipo: Journal Article Palavras-chave: Alternation; Categorical data; Clustering; Conditional distribution; Forvalues; P-value; Permutation; Run; Sequence; Simulate; Simulation; Research Methods/ Statistical Methods.
Ano: 2003 URL: http://purl.umn.edu/116095
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Forecasting Housing Prices under Different Submarket Assumptions AgEcon
Chen, Zhuo; Cho, Seong-Hoon; Poudyal, Neelam C.; Roberts, Roland K..
This research evaluated forecasting accuracy of hedonic price models based on a number of different submarket assumptions. Using home sale data for the City of Knoxville and vicinities merged with geographic information, we found that forecasting housing prices with submarkets defined using expert knowledge and by school district and combining information conveyed in different modeling strategies are more accurate and efficient than models that are spatially aggregated, or with submarkets defined by statistical clustering techniques. This finding provided useful implications for housing price prediction in an urban setting and surrounding areas in that forecasting models based on expert knowledge of market structure or public school quality and simple...
Tipo: Conference Paper or Presentation Palavras-chave: Clustering; Forecasting; Hedonic price; Housing Submarket; Demand and Price Analysis; C53; R21.
Ano: 2007 URL: http://purl.umn.edu/9689
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Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production. Repositório Alice
FREITAS, R. G.; MISSIO, R. F.; MATOS, F. S.; RESENDE, M. D. V. de; DIAS, L. A. S..
Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhão manso, is a highly promising species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia. We have made the first genetic evaluation of J. curcas collected from Brazil. Our objective was to quantify genetic diversity and to estimate genetic parameters for growth and production traits and seed oil...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Oil content; Genetic diversity; Heritability; Clustering; Genetic correlation.
Ano: 2011 URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/897234
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How do coral reef Gastropods feel about nuclear blasts? A long-term study of the effects of man-made perturbations ArchiMer
Lanctot, Jl; Legendre, P; Salvat, B.
The resistance to perturbations of reef-dwelling gastropod assemblages was studied on the seaward reefs of Fangataufa atoll (French Polynesia) after their exposure to atmospheric nuclear tests, a major man-made perturbation. We focused on two important aspects: (1) the temporal evolution of the densities of the most important species before and after the tests, and (2) the temporal evolution of the spatial structure of the assemblages. Three transects, crossing several geomorphological zones, were established on the seaward reefs of the atoll. Each transect was sampled at irregular time intervals during a twenty-year period. Several univariate and multivariate methods were used to study (1) the temporal fluctuations in species abundances and ranks, and (2)...
Tipo: Text Palavras-chave: Atmospheric nuclear tests; Clustering; Coral reefs; Gastropods; Perturbation.
Ano: 1997 URL: http://archimer.ifremer.fr/doc/00093/20394/18061.pdf
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Identification de « paysages hydrologiques » dans les eaux marines sous juridiction française (France métropolitaine) ArchiMer
Gailhard-rocher, Isabelle; Huret, Martin; Lazure, Pascal; Vandermeirsch, Frederic; Gatti, Julie; Garreau, Pierre; Gohin, Francis.
Dans le contexte de l’évaluation initiale des eaux communautaires demandée par la Directive cadre stratégie pour le milieu marin (DCSMM), les états membres sont chargés de décrire les types d’habitats dominants de la colonne d’eau pour chaque sous-région marine. La présente étude s’inscrit dans ce contexte et a pour objectif de décrire les principales structures hydrologiques de la colonne d’eau. Sur la base des données existantes et des travaux antérieurs, il s’agit de classer les masses d'eau en fonction de critères physiques (température, salinité, turbidité, stratification), reconnus d’intérêt pour les espèces pélagiques et l’écosystème en général, et ainsi de définir une cartographie de l’habitat pélagique moyen. Les données utilisées correspondent...
Tipo: Text Palavras-chave: DCSMM; Habitat pélagique; Classification; Indices hydrologiques; Distribution des espèces; KeywordsMSFD; Pelagic Habitat; Clustering; Hydrological indices; Species distribution.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00069/18018/15547.pdf
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Instrumental variables and GMM: Estimation and testing AgEcon
Baum, Christopher F.; Schaffer, Mark E.; Stillman, Steven.
We discuss instrumental variables (IV) estimation in the broader context of the generalized method of moments (GMM), and describe an extended IV estimation routine that provides GMM estimates as well as additional diagnostic tests. Stand-alone test procedures for heteroskedasticity, overidentification, and endogeneity in the IV context are also described.
Tipo: Journal Article Palavras-chave: Instrumental variables; Generalized method of moments; Endogeneity; Heteroskedasticity; Overidentifying restrictions; Clustering; Intra-group correlation; Research Methods/ Statistical Methods.
Ano: 2002 URL: http://purl.umn.edu/116029
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Intelligent data analysis - support for development of SMEs sector AgEcon
Grljevic, Olivera; Bosnjak, Sasa; Bosnjak, Zita.
The paper studies possibilities of intelligent data analysis application for discovering knowledge hidden in small and medium-sized enterprises’ (SMEs) data, on the territory of the province of Vojvodina. The knowledge revealed by intelligent analysis, and not accessible by any other means, could be the valuable starting point for working out of proactive and preventive actions for the development of the SMEs sector.
Tipo: Journal Article Palavras-chave: Intelligent data analysis; CRISP-DM; Clustering; Small and medium enterprises.; Research and Development/Tech Change/Emerging Technologies; C8; L2.
Ano: 2009 URL: http://purl.umn.edu/94579
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Macro Level Economic Evaluation of Manure Application Rates Using CEEOT-MMS AgEcon
Osei, Edward.
Alternative manure application rates represent an integral part of current nutrient management efforts on animal feeding operations (AFOs). Previous studies have indicated that lower manure application rates tend to increase farm production costs. In this study, the Comprehensive Economic and Environmental Optimization Tool - Macro Modeling System (CEEOT-MMS) was used to evaluate the farm-level economic implications of alternative manure application rates for all AFOs in the 48 contiguous states of the U.S. Representative farms derived through statistical disaggregation of national databases and K-means clustering were simulated within the the Farm-level Economic Model (FEM) to determine the economic impacts of four manure application rates. The highest...
Tipo: Conference Paper or Presentation Palavras-chave: FEM; CEEOT-MMS; Animal feeding operations; Clustering; Costs; Manure; Phosphorus; Crop Production/Industries.
Ano: 2008 URL: http://purl.umn.edu/6240
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Mapeamento da vegetação por meio de séries de imagens NDVI usando mineração de dados: comparação dos sensores AVHRR/NOAA e MODIS/Terra. Repositório Alice
SCRIVANI, R.; GONÇALVES, R. R. do V.; ZULLO JÚNIOR, J.; ROMANI, L. A. S..
Este artigo propõe o mapeamento automático do uso/cobertura da terra por meio de sensores de baixa resolução espacial e alta resolução temporal comparando os resultados obtidos com uso de séries de NDVI dos sensores MODIS e AVHRR.
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Séries temporais; Análise de regressão; Agrupamento; Cana-de-açúcar; Clustering; Sensoriamento remoto; Remote sensing; Time series analysis; Regression analysis; Cluster analysis; Sugarcane.
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1028842
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Measuring connectedness among herds in mixed linear models: From theory to practice in large-sized genetic evaluations Inra
Fouilloux; Clément; Laloë, D..
Tipo: Journal Article Palavras-chave: Connectedness; Clustering; BLUP; Accuracy.
Ano: 2008 URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008ef39826f&uri=/notices/prodinra1/2009/12/
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Modeling Site Specific Heterogeneity in an On-Site Stratified Random Sample of Recreational Demand AgEcon
Sardana, Kavita; Bergstrom, John C..
Using estimation of demand for the George Washington/Jefferson National Forest as a case study, it is shown that in a stratified/clustered on-site sample, latent heterogeneity needs to be accounted for twice: first to account for dispersion in the data caused by unobservability of the process that results in low and high frequency visitors in the population, and second to capture unobservable heterogeneity among individuals surveyed at different sites according to a stratified random sample (site specific effects). It is shown that both of the parameters capturing latent heterogeneity are statistically significant. It is therefore claimed in this paper, that the model accounting for site-specific effects is superior to the model without such effects....
Tipo: Conference Paper or Presentation Palavras-chave: Recreational Demand models; Clustering; Subject-specific effects; Truncated Stratified Negative Binomial Model; Overdispersion; Environmental Economics and Policy.
Ano: 2011 URL: http://purl.umn.edu/103868
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Multivariate analyses of live-animal ultrasound carcass traits of composite cattle. Repositório Alice
SALVIAN, M.; RAMÍREZ-DÍAZ, J.; CUCCO, D. C.; SANTANA, M. H.; BONIN, M. N.; GOMES, R. da C.; FERRAZ, J. B. S.; MOURÃO, G. B..
2013
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: Agglomerative method; Clustering; Composite breed; Quality carcass; Animal breeding; Beef cattle.
Ano: 2013 URL: http://www.alice.cnptia.embrapa.br/handle/doc/972591
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Relationships with market intermediaries: the case of vegetable cluster marketing in Southern Philippines AgEcon
Axalan, Jerick T.; Murray-Prior, Roy B.; Concepcion, Sylvia B.; Lamban, Ruby Jane G.; Real, Rodel R.; Montiflor, Marilou O.; Batt, Peter J.; Rola-Rubzen, Maria Fay; Bacus, Recarte H.; Israel, Floro T.; Apara, Dante A..
Effective relationship among partners is a key in strengthening collaborative marketing efforts. One of the collaborative marketing efforts is through clustering of farmer to link into market. This study examined the level of relationship of vegetable cluster farmers with their market intermediaries - cluster and the downstream buyers. A total of 81 vegetables farmers in Southern Philippines were surveyed to determine their relationship level on trust, power-dependence, relationship-specific investments and satisfaction. Comparison between clusters and downstream buyers were made using ANOVA and Welch Test. The study found that farmers have high level of trust to their clusters compared to their downstream buyers. The high level of trust is attributed to...
Tipo: Presentation Palavras-chave: Trust; Relationships; Vegetable; Clustering; Southern Philippines; Marketing.
Ano: 2012 URL: http://purl.umn.edu/124222
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Revisiting "privacy preserving clustering by data transformation". Repositório Alice
OLIVEIRA, S. R. de M.; ZAÏANE, O..
Preserving the privacy of individuals when data are shared for clustering is a complex problem. The challenge is how to protect the underlying data values subjected to clustering without jeopardizing the similarity between objects under analysis. In this short paper, we revisit a family of geometric data transformation methods (GDTMs) that distort numerical attributes by translations, scalings, rotations, or even by the combination of these geometric transformations. Such a method was designed to address privacy-preserving clustering, in scenarios where data owners must not only meet privacy requirements but also guarantee valid clustering results. We offer a detailed, comprehensive and up-to-date picture of methods for privacy-preserving clustering by...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Clusterização; Privacidade em mineração de dados; Recuperação da informação; Clustering; Information retrieval.
Ano: 2010 URL: http://www.alice.cnptia.embrapa.br/handle/doc/863828
Registros recuperados: 28
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