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Palavra-chave Spatial dependence (26) Geostatistics (10) Community/Rural/Urban Development (5) Semivariogram (4) Food Consumption/Nutrition/Food Safety (3) Assessed property values (2) C21 (2) Dairy farming (2) Dependência espacial (2) Food Security and Poverty (2) GMM (2) Health Economics and Policy (2) Hedonic pricing models (2) Heterogeneidade espacial (2) I18 (2) Land Economics/Use (2) R11 (2) Ukraine (2) Agglomeration. (1) Agribusiness (1) Mais... Tipo do documento Info:eu-repo/semantics/article (13) Conference Paper or Presentation (9) Working or Discussion Paper (3) Parte de livro (1) Ano 2021 (1) 2020 (1) 2019 (3) 2018 (2) 2017 (2) 2016 (1) 2014 (2) 2011 (1) 2010 (1) 2009 (4) 2008 (5) 2007 (1) 2005 (1) 2002 (1) Mais... País Brazil (14) United States (12) Idioma Inglês (23) Português (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 26 Primeira ... 1 2 ... Última Some aspects about the spatial dependence index for variability of soil attributes Ciência Rural Santos,Eduardo Lucas Ensslin dos; Seidel,Enio Júnior; Pazini,Juliano de Bastos; Oliveira,Marcelo Silva de; Appel Neto,Edemar; Barbosa,Ismael Canabarro. ABSTRACT: The main purpose of this article was to evaluate the behavior and relationship of the range and components of SDI (Spatial Dependence Index) in general and in function of field factors such as soil types, type of attribute and soil layers. This evaluation was based on real data collected in national journals. It was noticed that the parameter range, in general and for different field factors, presented asymmetric positive behavior. The components of the SDI showed approximately symmetrical behavior. The SDI can capture the range behavior more intensely (the spatial variability behavior in the horizontal direction of the semivariogram), and, in a less intense way, the behavior of the contribution and sill parameters (the spatial dependence... Tipo: Info:eu-repo/semantics/article Palavras-chave: Spatial dependence; Geostatistics; Semivariogram; Field factors. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000600252 SPATIAL VARIABILITY OF THE WATER DEPTH APPLIED BY FIXED SPRINKLER IRRIGATION SYSTEMS REA Tamagi,Jorge T.; Uribe-Opazo,Miguel A.; Vilas Boas,Marcio A.; Johann,Jerry A.; Guedes,Luciana P. C.. Abstract The uniformity of water application is an important factor in the evaluation of sprinkler irrigation systems. This uniformity depends on the type of sprinkler and its operating conditions, such as the arrangement and spacing between the sprinklers in the area; velocity and wind direction during the period of water application and the pressure variation of the irrigation system. The objective of this study was to model, analyze and compare the structure of spatial dependence, as well as the spatial variability of the water depths applied by a sprinkler irrigation system with compensating and non-compensating sprinklers, using geostatistical methods and measurements of accuracy or similarity between the applied water depth maps. The experiment was... Tipo: Info:eu-repo/semantics/article Palavras-chave: Compensating sprinklers; Noncompensating sprinklers; Spatial dependence. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000200188 SPATIAL AUTOCORRELATION OF PHYSICAL ATTRIBUTES OF AN OXISOL REA Oliveira,Job T. de; Oliveira,Rubens A. de; Cunha,Fernando F. da; Santos,Eduardo S. dos. ABSTRACT Studies that seek to identify a smaller number of soil attributes that represent others can generate less expenditure of time and financial resources for monitoring cultivated areas. Thus, this study aimed to analyze the spatial distribution and spatial autocorrelation of physical attributes of an Oxisol (Latossolo Vermelho Amarelo, Brazilian Soil Classification System). The evaluated attributes consisted of soil density (SD), total porosity (TP), free porosity (FP), field capacity (FC), permanent wilt point (PW), and total water availability (TW). Semivariogram adjustments and semivariance estimates were performed to characterize the structure and magnitude of the spatial dependence of soil attributes. The attributes were distributed on thematic... Tipo: Info:eu-repo/semantics/article Palavras-chave: Precision agriculture; Spatial dependence; Geostatistics; Moran index. Ano: 2021 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000200255 REDUCTION OF SAMPLE SIZE IN THE ANALYSIS OF SPATIAL VARIABILITY OF NONSTATIONARY SOIL CHEMICAL ATTRIBUTES REA Maltauro,Tamara C.; Guedes,Luciana P. C.; Uribe-Opazo,Miguel A.. ABSTRACT In the study of spatial variability of soil attributes, it is essential to define a sampling plan with adequate sample size. This study aimed to evaluate, through simulated data, the influence of parameters of the geostatistical model and sampling configuration on the optimization process, and resize and reduce the sample size of a sampling configuration of a commercial area composed of 102 points. For this, an optimization process called genetic algorithm (GA) was used to optimize the efficiency of the geostatistical model estimation based on the Fisher information matrix. The simulated data evidenced that the variation of the nugget effect or practical range did not significantly alter the sample size. GA was efficient in reducing the sample... Tipo: Info:eu-repo/semantics/article Palavras-chave: Fisher information matrix; Genetic algorithm; Geostatistics; Spatial dependence. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800056 GEOSTATISTICAL MODELING OF SOYBEAN YIELD AND SOIL CHEMICAL ATTRIBUTES USING SPATIAL BOOTSTRAP REA Dalposso,Gustavo H.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Bastiani,Fernanda De; Galea,Manuel. ABSTRACT The goal of this study was to use the spatial bootstrap method to model the spatial dependence structure of soybean yield and soil chemical attributes in an agricultural area. The study involved developing confidence intervals in probability plots to determine the probability distributions assumed by the data; determine the empirical distributions of the semivariances and model parameters, allowing to obtain statistics and confidence intervals; and to construct maps for the variables. The quantile-quantile plots indicated that the data follows a normal distribution. The confidence intervals for the semivariances helped to model the spatial dependence structure, and the descriptive statistics of the bootstrap replicates of the model parameters... Tipo: Info:eu-repo/semantics/article Palavras-chave: Confidence intervals; Quantile-quantile plot; Resampling; Spatial dependence. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000300350 SPATIAL VARIABILITY OF SOYBEAN YIELD THROUGH A REPARAMETERIZED T-STUDENT MODEL REA Schemmer,Rosangela C.; Uribe-Opazo,Miguel A.; Galea,Manuel; Assumpção,Rosangela A. B.. ABSTRACT: The t-Student distribution has been used to the spatial dependence modelling of soybean yield as an alternative to the normal distribution, being used for data with heavier tails or discrepant values. However, a usual Student t-distribution does not allow direct comparisons of geostatistical methods with a normal distribution. The aim of this study was to assess the soybean yield spatial variability through a reparameterized t-Student linear model, comparing the results with those of a Gaussian linear model. For parameter estimation, a complete maximum likelihood (CML) method was used through an expectation-maximization (EM) algorithm. The maps constructed with both reparameterized t-Student and normal distributions are dissimilar and present a... Tipo: Info:eu-repo/semantics/article Palavras-chave: EM algorithm; Spatial dependence; Geostatistics; Complete maximum likelihood. Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400760 RAINFALL ZONING FOR COCOA GROWING IN BAHIA STATE (BRAZIL) USING FUZZY LOGIC REA Franco,Laís B.; Almeida,Ceres D. G. C. de; Freire,Martiliana M.; Franco,Gustavo B.; Silva,Samuel de A.. ABSTRACT Cacao is a species of great economic and social importance. Expanding the area grown with this crop has been limited by its climatic requirements. Agroclimatic zoning for agricultural sector and creation of land suitability maps by fuzzy logic contribute to such production expansion. In this sense, this study aimed to develop rainfall zoning for cacao in Bahia state using the fuzzy logic method. The used data came from rainfall historical series of 519 meteorological stations distributed throughout the state. Geostatistical analyses were used to quantify the spatial dependence degree of studied variable and kriging was used to develop maps representing mean monthly rainfall. These maps were submitted to continuous classification by fuzzy mapping... Tipo: Info:eu-repo/semantics/article Palavras-chave: Land suitability; Mapping; Spatial dependence; Theobroma cacao L.. Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000800048 Aplicação dos conceitos geoestatísticos para o manejo da irrigação em videira no Vale do Submédio São Francisco. Infoteca-e NASCIMENTO, P. S.; SILVA, J. A.; COSTA, B. R. S.; BASSOI, L. H.. A otimização na aplicação dos recursos hídricos constitui uma das preocupações da agricultura irrigada. Nesse sentido, esta pesquisa foi desenvolvida com o objetivo de aplicar o conceito de zonas homogêneas do solo para a realização do manejo diferenciado da irrigação em um pomar de videira. O experimento foi conduzido em área de produção comercial, localizada no Perímetro Irrigado Senador Nilo Coelho, em Petrolina-PE. Foi selecionada uma área com 40 fileiras de plantas e 82 plantas por fileira, em um pomar de videira cultivar Thompson Seedless sobre o porta-enxerto SO4, com 1 difusor por planta e conduzida no sistema de latada. Amostras de solo foram coletadas nas profundidades de 0,0-0,2 e 0,2-0,4 m para a determinação da curva de retenção de água no... Tipo: Parte de livro Palavras-chave: Vale do São Francisco; Available soil water; Spatial dependence; Uva; Irrigação; Manejo; Vitis Vinifera; Grapes; Geostatistics. Ano: 2014 URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1008326 Semivariogram models for estimating fig fly population density throughout the year PAB Batistella Pasini,Mauricio Paulo; Dal'Col Lúcio,Alessandro; Cargnelutti,Alberto Filho. The objective of this work was to select semivariogram models to estimate the population density of fig fly (Zaprionus indianus; Diptera: Drosophilidae) throughout the year, using ordinary kriging. Nineteen monitoring sites were demarcated in an area of 8,200 m2, cropped with six fruit tree species: persimmon, citrus, fig, guava, apple, and peach. During a 24 month period, 106 weekly evaluations were done in these sites. The average number of adult fig flies captured weekly per trap, during each month, was subjected to the circular, spherical, pentaspherical, exponential, Gaussian, rational quadratic, hole effect, K-Bessel, J-Bessel, and stable semivariogram models, using ordinary kriging interpolation. The models with the best fit were selected by... Tipo: Info:eu-repo/semantics/article Palavras-chave: Zaprionus indianus; Geostatistics; Integrated pest management; Monitoring; Regionalized variables; Spatial dependence. Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2014000700493 ANÁLISE EXPLORATÓRIA DE DADOS ESPACIAL DA INCIDÊNCIA DE POBREZA NA ILHA DE SANTIAGO DE CABO VERDE AgEcon Baptista, Antonio Jose Medina dos Santos; Santos, Cristiane Marcia. Combater a pobreza sempre foi um objetivo presente em grande parte das políticas publicas implementadas em Cabo Verde. Esse tema tem despertado atenção da comunidade de investigadores, que ao longo do tempo enriqueceram o acervo de documentos de analise da pobreza. O presente artigo teve a pretensão de analisar a incidência da pobreza em Cabo Verde especificamente na identificação de cluster de pobreza e indicação da dependência espacial da incidência da pobreza na Ilha de Santiago. Os resultados permitiram evidenciar a existência de padrões espaciais distintos em relação à incidência da pobreza. Os vizinhos tendem a apresentar valores semelhantes entre, si e diferentes das demais localidades relativamente mais afastadas. Uma das principais conclusões do... Tipo: Conference Paper or Presentation Palavras-chave: Pobreza; Cabo Verde; Heterogeneidade espacial; Dependência espacial; Poverty; Cape Verde; Space heterogeneity; Spatial dependence; Food Security and Poverty. Ano: 2008 URL: http://purl.umn.edu/113180 ANÁLISE ESPACIAL DOS PRINCIPAIS DETERMINANTES DA RENDA PER CAPITA DOS MUNICÍPIOS BRASILEIROS AgEcon Lazzarotto, Joelsio Jose; Lima, Joao Eustaquio de. Como no Brasil existem grandes heterogeneidades com relação à renda per capita, buscou-se estudar importantes aspectos determinantes da formação dessa renda nos diversos municípios. Com base em dados de 5.425 municípios, foram empregadas técnicas de análise exploratória de dados espaciais e de estimação de modelos econométricos espaciais. Dentre os resultados obtidos, pode-se destacar três: 1) existem grandes disparidades municipais relacionadas com os rendimentos individuais; 2) a análise exploratória de dados espaciais indicou a existência de dependência espacial envolvendo a renda per capita média dos municípios; e 3) os modelos econométricos estimados evidenciaram que, variações relacionadas com escolaridade, nível de emprego, desempenho dos setores... Tipo: Conference Paper or Presentation Palavras-chave: Dependência espacial; Heterogeneidade espacial; Clusters municipais; Spatial dependence; Spatial heterogeneity; Municipal clusters; Financial Economics. Ano: 2008 URL: http://purl.umn.edu/103145 EXPERT OPINION VERSUS TRANSACTION EVIDENCE: USING THE REILLY INDEX TO MEASURE OPEN SPACE PREMIUMS IN THE URBAN-RURAL FRINGE AgEcon Cotteleer, Geerte; Stobbe, Tracy; van Kooten, G. Cornelis. Due to economic and population growth farmland and to a lesser extend other undeveloped areas are under pressure in the urban-rural fringe in British Columbia, Canada. The objectives of this paper are to determine if residential property values near Victoria, BC include open-space premiums for farmland or parks or both, and to determine if using assessed values instead of market prices of the property result in the same findings. We estimate a SUR (Seemingly Unrelated Regression) model with two hedonic pricing equations, one with actual market values as the dependent variable and one with assessed property values, and compare the resulting estimates of shadow prices for open space amenities. Furthermore, we take account of spatial autocorrelation and... Tipo: Conference Paper or Presentation Palavras-chave: Hedonic pricing models; Assessed property values; Value of open space; Geographical Information System; Reilly; GMM; Spatial dependence; Community/Rural/Urban Development; Land Economics/Use; Research Methods/ Statistical Methods. Ano: 2008 URL: http://purl.umn.edu/6705 Mapping preferences for the restoration of environmental damage caused by illegal dumping AgEcon Campbell, Danny; Sinclair, Victoria. In this paper we use a discrete choice experiment to elicit the economic benefits associated with restoring environmental damage caused by illegal dumping activities. Our study focuses on an extensive rural upland area close to Belfast, where illegal dumping activities are prevalent. Using a random parameters logit model to account for unobserved taste heterogeneity, we exploit the panel nature of the dataset to retrieve partworths, or willingness to pay (WTP) values, for every individual in the sample. We subsequently investigate the existence of spatial dependence of these estimates. As a means of benefit transfer, we also employ geostatistical methods to extend across the whole of the study area the WTP estimates derived from the collected data. The... Tipo: Conference Paper or Presentation Palavras-chave: Discrete choice experiments; Environmental restoration; Geostatistical analysis; Random parameters logit; Spatial dependence; Illegal dumping; Willingness to pay; C25; Q51; Q53. Ano: 2008 URL: http://purl.umn.edu/36772 Space, Government Payments, and Off-Farm Labor Response of Principal Farm Operators: A County-Level Analysis AgEcon Shrestha, Sundar S.; Findeis, Jill L.. We examine the effects of space and government payments on off-farm employment among principal farm operators for the entire US as well as for ERS/USDA farm resource regions. Spatial dependency in off-farm employment of principal farm operators in the U.S. overall is evident; however, this is not the case for all farm resource regions. While the effects of government payments overall are significant for the U.S., important variations exist by farm program type and across ERS/USDA regions. Tipo: Conference Paper or Presentation Palavras-chave: Government payments; Off-farm employment; Off-farm labor supply; Spatial dependence; ERS regions; Farm Management. Ano: 2005 URL: http://purl.umn.edu/19511 Price Support, Efficiency and Technology Change of Ukrainian dairy farms: Spatial dependence in the components of productivity growth AgEcon Nivievskyi, Oleg. Even after more than 15 years of transition from plan to market, agriculture in Ukraine still faces many challenges in terms of its structure. In particular, both the recently approved WTO accession, and the ongoing negotiations on a free trade agreement with the EU will require improvements in productivity and competitiveness at the farm level. The evidence in the literature based on either data envelopment (DEA) or stochastic frontier analysis (SFA) in Ukraine points to significant heterogeneity of technical efficiency and TFP scores. However, the drivers underlying these patterns have not been explicitly studied yet. Using farm-level data for 2004-2005, this paper investigates the determinants of productivity growth in Ukrainian dairy farming. The... Tipo: Conference Paper or Presentation Palavras-chave: Ukraine; Dairy farming; TFP; Spatial dependence; Production Economics; Productivity Analysis. Ano: 2009 URL: http://purl.umn.edu/51403 Regional Convergence in the European Union (1985-1999): A Spatial Dynamic Panel Analysis AgEcon Badinger, Harald; Muller, Werner G.; Tondl, Gabriele. We estimate the speed of income convergence for a sample of 196 European NUTS 2 regions over the period 1985-1999. So far there is no direct estimator available for dynamic panels with strong spatial dependencies. We propose a two-step procedure, which involves first spatial filtering of the variables to remove the spatial correlation, and application of standard GMM estimators for dynamic panels in a second step. Our results show that ignorance of the spatial correlation leads to potentially misleading results. Applying a system GMM estimator on the filtered variables, we obtain a speed of convergence of 6.9 per cent and a capital elasticity of 0.43. Tipo: Working or Discussion Paper Palavras-chave: Growth; Convergence; Spatial dependence; Spatial filtering; Dynamic panels; GMM; Community/Rural/Urban Development; C23; O00; R11. Ano: 2002 URL: http://purl.umn.edu/26329 Does Where You Live Make You Fat? Obesity and Access to Chain Grocers AgEcon Chen, Susan E.; Florax, Raymond J.G.M.; Snyder, Samantha D.. This paper investigates the role that aspects of the physical environment play in determining health outcomes in adults as measured by body mass index (BMI). Using spatial econometric techniques that allow for spatial spillovers and feedback processes, this research specifically examines how differing levels of access to large chain grocers has on individual health outcomes. While other studies have investigated the impact of proximity to food retailers, the point-coordinate data used in this paper is uniquely suited to spatial econometric estimation at the individual level. In addition to modeling spatial dependence and allowing for unobserved neighborhood effects, the flexibility of the model is increased by incorporating potential spatial... Tipo: Working or Discussion Paper Palavras-chave: Body mass index; Obesity; Spatial dependence; Obesogenic environments; Food Consumption/Nutrition/Food Safety; Food Security and Poverty; Health Economics and Policy; C31; D12; I12; I18. Ano: 2009 URL: http://purl.umn.edu/53838 Expert Opinion versus Transaction Evidence: Using the Reilly Index to Measure Open Space Premiums in the Urban-Rural Fringe AgEcon Cotteleer, Geerte; Stobbe, Tracy; van Kooten, G. Cornelis. Due to economic and population growth farmland and to a lesser extend other undeveloped areas are under pressure in the urban-rural fringe in British Columbia, Canada. The objectives of this paper are to determine if residential property values near Victoria, BC include open-space premiums for farmland, parks or golf courses, and to determine if using assessed values instead of market prices of the property result in the same findings. We estimate a Seemingly Unrelated Regression (SUR) model with two hedonic pricing equations, one with actual market values as the dependent variable and one with assessed property values, and compare the resulting estimates of shadow prices for open space amenities. Furthermore, we take account of spatial autocorrelation and... Tipo: Working or Discussion Paper Palavras-chave: Hedonic pricing models; Spatial dependence; Assessed property values; Open space; Community/Rural/Urban Development; Land Economics/Use; R14; R52; C21; Q20; H23. Ano: 2008 URL: http://purl.umn.edu/37085 Does Where We Live Matter? Understanding the Link Between Obesity and the Market for Food AgEcon Chen, Susan E.; Florax, Raymond J.G.M.; Snyder, Samantha D.. Paper is under revision. Removed at author's request 10/27/08. Tipo: Conference Paper or Presentation Palavras-chave: Incidence of obesity and overweight; Spatial lag model; Spatial dependence; Food Consumption/Nutrition/Food Safety; Health Economics and Policy; C21; D1; I18; J10. Ano: 2007 URL: http://purl.umn.edu/9682 Agglomeration Economies in Ukrainian Dairy Sector: a Marked Point Process Approach AgEcon Brümmer, Bernhard; von Cramon-Taubadel, Stephan; Nivievskyi, Oleg; Schlather, Martin. Even after more than 15 years of transition from plan to market, agriculture in Ukraine still faces many challenges in terms of its structure. The evidence in the literature points to significant heterogeneity of technical efficiency and productivity scores in Ukraine. Moreover, both the recently approved WTO accession, and the ongoing negotiations on a free trade agreement with the EU will require further improvements in productivity and competitiveness at the farm level. Using farm-level data for 2004-2005, we study the presence and possible causes of agglomeration economies in Ukrainian dairy sector. One of the most important results is that there are agglomeration effects in the sector. The performance of dairy farms is influenced by the performance of... Tipo: Conference Paper or Presentation Palavras-chave: Ukraine; Dairy farming; Order-m frontier; Spatial dependence; Agglomeration.; Agribusiness; Agricultural and Food Policy; Community/Rural/Urban Development; Food Consumption/Nutrition/Food Safety; Labor and Human Capital. Ano: 2010 URL: http://purl.umn.edu/94990 Registros recuperados: 26 Primeira ... 1 2 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco