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	Provedor de dados AgEcon (9) ArchiMer (4) Infoteca-e (1) Scientia Agricola (1) REA (1) Rev. Bras. Ciênc. Solo (1) Mais... Autor Fadiga, Mohamadou L. (3) Gao, Xiaoming (2) Mazzocchi, Mario (2) Misra, Sukant K. (2) Patterson, Paul M. (2) Richards, Timothy J. (2) ALMEIDA, R. G. de (1) Bacchi,O. O. S. (1) Barbosa,Emanuel Pimentel (1) Brasseur, Pierre (1) CARROMEU, C. (1) Cassaro,F. A. M. (1) Chapron, Bertrand (1) Chen, Ming (1) Collard, Fabrice (1) Dambacher, Jeffrey M. (1) Dourado-Neto,D. (1) Dynia,José Flávio (1) Fablet, Ronan (1) Fang,Susu (1) Mais... Palavra-chave Kalman filter (17) International Relations/Trade (3) Unobserved components (3) Almost Ideal Demand System (2) BSE (2) C32 (2) Commodity promotion (2) Crop Production/Industries (2) DYMIMIC (2) Data assimilation (2) Demand system (2) Fiber prices (2) Filtre de Kalman (2) Food Consumption/Nutrition/Food Safety (2) Fresh fruit (2) LA/AIDS (2) Latent variables (2) Marketing (2) Productivity Analysis (2) State-space (2) Mais... Tipo do documento Journal Article (4) Text (4) Conference Paper or Presentation (3) Info:eu-repo/semantics/article (3) Working or Discussion Paper (2) Folhetos (1) Mais... Ano 2022 (1) 2018 (1) 2017 (1) 2013 (1) 2008 (1) 2007 (1) 2006 (1) 2005 (4) 2004 (2) 2003 (1) 2001 (1) 1999 (1) 1998 (1) Mais... País United States (9) Brazil (4) France (4) Idioma Inglês (15) Francês (1) Português (1)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 17 Primeira ... 1 ... Última MEASUREMENT AND ANALYSIS OF A FIELD AREA BASED ON AN ADAPTIVE KALMAN FILTER REA Fang,Susu; Wang,Zengcai; Zhong,Wenjun. ABSTRACT: This paper proposed the use of an adaptive Kalman filter (AFK) to improve Global Positioning System (GPS) positioning accuracy to measure a tractor operational area. First, we used MATLAB to identify the operation trajectory. Then, we used different colors to show the area of operation. Finally, we used an image-processing method to calculate the effective operational area, actual operational area, and repeat and omission rates. We used these rates to evaluate the tractor efficiency. The experiment indicated that the Kalman filter improved the accuracy of GPS single-point positioning. To test the GPS area-measurement precision, field area measurements were taken. We used GPS to measure standard figures and some irregular figures. The results... Tipo: Info:eu-repo/semantics/article Palavras-chave: Tractor; Kalman filter; Global Positioning System (GPS); Operational area. Ano: 2017 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000500867 Uso de Filtro de Kalman para processamento de dados de pesagem diária para bovinos de corte. Infoteca-e HIGA, R. H.; CARROMEU, C.; OLIVEIRA, C. C. de; ALMEIDA, R. G. de; SPERANZA, E. A.. Resumo - O presente estudo analisa a utilização de Filtros de Kalman (FK) para processamento de dados de pesagem diária de bovinos de corte utilizando um conjunto composto por pesagens diárias de 36 animais, coletados por 209 dias. Os resultados demonstram que o processamento de dados de pesagem diária com o Filtro de Kalman Polinomial (FKP) reduz o nível de ruído presente nos dados, viabiliza a extração do ganho de peso diário por animal, bem como torna factível a realização de predições do peso, por animal, 30 dias à frente. Adicionalmente, a utilização do FK não impacta a tomada de decisão no contexto do lote, uma vez que o peso médio dos animais no lote também não é afetado pelo FK. Tipo: Folhetos Palavras-chave: Bovino de corte; Bovinos de corte; Filtro de Kalman; Pecuária de precisão; Ganho de peso diário; Kalman filter; Precision livestock farming; Daily weight gain; Gado Nelore; Peso; Beef cattle. Ano: 2022 URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/1150330 Contribution à l'étude de la dynamique du thon rouge Atlantique - Approches écologiques et océanographiques ArchiMer Royer, Francois. [1] The spatial and temporal dynamics of Atlantic bluefin tuna, Thunnus thynnus, are here investigated through data analysis and statistical modelling. The local, regional and global scales are considered successively. A phenomenological approach is favoured, as well the extended use of image processing tools and estimation theory techniques. Their potential role in partially observed or ill-defined problems in marine ecology is presented and discussed. The acute need for frequency-explicit methods is in particular stressed out. Hypothesis testing and significance testing of ecological space/time processes are further discussed. [2] The first chapter depicts how surface fronts can structure the pelagic habitat: dedicated detection and mapping tools are... Tipo: Text Palavras-chave: Archival tags; Kalman filter; Density dependence; Oceanic fronts; Time series; Thunnus thynnus; Marques archives; Filtre de Kalman; Densite dependence; Fronts oceaniques; Series temporelles; Thunnus thynnus. Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/these-636.pdf The relative importance of environmental stochasticity, interspecific interactions, and observation error: Insights from sardine and anchovy landings ArchiMer Hosack, Geoffrey R.; Trenkel, Verena; Dambacher, Jeffrey M.. Long-term time series of sardine and anchovy landings often suggest negative dependence between these species, and an array of mechanisms have been proposed as explanations. We reduce these propositions to four basic hypotheses of (1) independence, (2) correlated process noise, (3) interspecific interactions, and (4) correlated observational error. We use a Bayesian approach to develop priors for parsimonious state space models with both process noise and observation error that represent each of these hypotheses, and apply this approach to five long-term time series of landings collected from the Pacific and Atlantic Oceans. Model comparison criteria suggest that the hypothesis of correlated process noise has the broadest support, where the temporal... Tipo: Text Palavras-chave: Adaptive Metropolis; Bayes factors; DIC; Gompertz model; Hyperstability; Kalman filter; Model comparison; Reactivity; Small pelagic fishes; Stability. Ano: 2013 URL: http://archimer.ifremer.fr/doc/00159/27072/26066.pdf Neural Network Based Kalman Filters for the Spatio-Temporal Interpolation of Satellite-Derived Sea Surface Temperature ArchiMer Ouala, Said; Fablet, Ronan; Herzet, Cedric; Chapron, Bertrand; Pascual, Ananda; Collard, Fabrice; Gaultier, Lucile. The forecasting and reconstruction of oceanic dynamics is a crucial challenge. While model driven strategies are still the state-of-the-art approaches in the reconstruction of spatio-temporal dynamics. The ever increasing availability of data collections in oceanography raised the relevance of data-driven approaches as computationally efficient representations of spatio-temporal fields reconstruction. This tools proved to outperform classical state-of-the-art interpolation techniques such as optimal interpolation and DINEOF in the retrievement of fine scale structures while still been computationally efficient comparing to model based data assimilation schemes. However, coupling this data-driven priors to classical filtering schemes limits their potential... Tipo: Text Palavras-chave: Data assimilation; Dynamical model; Kalman filter; Neural networks; Data-driven models; Interpolation. Ano: 2018 URL: https://archimer.ifremer.fr/doc/00481/59286/61979.pdf Data assimilation in a marine ecosystem model of the Ligurian Sea. ArchiMer Magri Hoeltzener, Stephanie; Brasseur, Pierre; Lacroix, Geneviève. The objective is to explore the potentialities of sequential statistical estimation methods to assimilate observations in a primary production biological model coupled to a vertical 1D hydrodynamical model characterised by a k-l turbulent closure. The assimilation method is derived from the SEEK filter (Singular Evolutive Extended Kalman filter), which uses an error subspace represented by multivariate empirical orthogonal functions (EOFs). Real data assimilation experiments collected at sea have been realised to reconstruct the variability of the Ligurian Sea ecosystem during the FRONTAL field experiment. Tipo: Text Palavras-chave: Ligurian Sea; Kalman filter; Data assimilation; Numeric modelling; Physical/biogeochemical model; Mer Ligure; Filtre de Kalman; Assimilation de données; Modélisation numérique; Océanographie physique/biogéochimique. Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-687.pdf Advertising and Retail Promotion of Washington Apples: A Structural Latent Variable Approach to Promotion Evaluation AgEcon Richards, Timothy J.; Gao, Xiaoming; Patterson, Paul M.. "Commodity promotion" consists of many activities, each designed to contribute to a consumer's product knowledge or influence tastes. However, both knowledge and tastes are unobservable, or latent, variables influencing demand. This paper specifies a dynamic structural model of fresh fruit demand that treats promotion and other socioeconomic variables as "causal" variables influencing these latent variables. Estimating this state-space model using a Kalman filter approach provides estimates of both the system parameters and a latent variable series. The results show that these latent effects contribute positively to apple and other fruit consumption, while reducing banana consumption. Tipo: Working or Discussion Paper Palavras-chave: Commodity promotion; Demand system; DYMIMIC; Fresh fruit; Kalman filter; LA/AIDS; Latent variables; Marketing. Ano: 1998 URL: http://purl.umn.edu/28547 A Latent-Variable Approach to Modelling Multiple and Resurgent Meat Scares in Italy AgEcon Mazzocchi, Mario; Lobb, Alexandra E.. This paper aims to measure the time pattern of multiple and resurgent food scares and their direct and cross-product impacts on consumer response. The Almost Ideal Demand System (AIDS) is augmented by a flexible stochastic framework which has no need for additional explanatory variables such as a media index. Italian aggregate household data on meat demand is used to assess the time-varying impact of a resurgent BSE crisis (1996 and 2000) and the 1999 Dioxin crisis. The impact of the first BSE crisis on preferences seems to be reabsorbed after a few months. The second wave of the scare at the end of 2000 had a much stronger effect on preferences and the positive shift in chicken demand continued to persist after the onset of the crisis. Empirical results... Tipo: Conference Paper or Presentation Palavras-chave: Meat demand; BSE; Shock; Almost Ideal Demand System; Kalman filter; Food Consumption/Nutrition/Food Safety; D12; I12. Ano: 2005 URL: http://purl.umn.edu/24509 Environmental Indices for the Chinese Grain Sector AgEcon Chen, Ming; Karp, Larry S.. Increased population pressure and political decisions have led to more intensive agricultural practices in China. As in other regions of the world, these practices can damage natural capital We use the Kalman filter and Chinese panel data to estimate an index of environmental productivity (natural capital), together with the parameters of environmental dynamics and the production function. These estimates show that intensive practices are likely to have had persistent, substantial, and statistically significant negative effects on productivity. Ignoring these effects can cause substantial misallocation of resources. The results illustrate the possibility of estimating sectoral environmental indices using data commonly available. Tipo: Working or Discussion Paper Palavras-chave: Chinese agriculture; Dynamic production; Environmental indices; Sustainability; Kalman filter; Crop Production/Industries; Environmental Economics and Policy; Productivity Analysis; QOl; Q21; C32; C43. Ano: 2001 URL: http://purl.umn.edu/6259 A Joint Characterization of German Monetary Policy and the Dynamics of the German Term Structure of Interest Rates AgEcon Fendel, Ralf. The paper develops an empirical no-arbitrage Gaussian affine term structure model to explain the dynamics of the German term structure of interest rates. In contrast to most affine term structure models two risk factors are linked to observable macroeconomics factors: output and inflation. The results indicate that the dynamics of the German term structure of interest rates can be sufficiently explained by expected variations in those macroeconomic factors plus an additional unobservable factor. Furthermore, we are able to extract a monetary policy reaction function within this no-arbitrage model that closely resembles empirical reaction functions that are based on the dynamics of the short rate only. Tipo: Journal Article Palavras-chave: Affine term structure models; Monetary policy rules; Kalman filter; Financial Economics; E43; E58; G12. Ano: 2008 URL: http://purl.umn.edu/50005 Common Trends, Common Cycles, and Price Relationships in the International Fiber Market - Evidence from a Seemingly Unrelated Structural Time Series AgEcon Fadiga, Mohamadou L.; Misra, Sukant K.. This study shows that the stochastic process that governs price fluctuations in the international fiber market has transitory and permanent components. The results also indicate structural relationships between cotton price and wool price, wool price and oil price, rayon price and cotton price, and between polyester price and cotton price. Tipo: Conference Paper or Presentation Palavras-chave: Unobserved components; State-space; Kalman filter; Fiber prices; Cofeature; International Relations/Trade; C32; Q11. Ano: 2005 URL: http://purl.umn.edu/35545 ADVERTISING AND RETAIL PROMOTION OF WASHINGTON APPLES: A STRUCTURAL LATENT VARIABLE APPROACH TO PROMOTION EVALUATION AgEcon Richards, Timothy J.; Gao, Xiaoming; Patterson, Paul M.. "Commodity promotion" consists of many activities, each designed to contribute to a consumer's product knowledge or influence tastes. However, both knowledge and tastes are unobservable, or latent, variables influencing demand. This paper specifies a dynamic structural model of fresh fruit demand that treats promotion and other socioeconomic variables as "causal" variables influencing these latent variables. Estimating this state-space model using a Kalman filter approach provides estimates of both the system parameters and a latent variable series. The results show that these latent effects contribute positively to apple and other fruit consumption, while reducing banana consumption. Tipo: Journal Article Palavras-chave: Commodity promotion; Demand system; DYMIMIC; Fresh fruit; Kalman filter; LA/AIDS; Latent variables; Marketing. Ano: 1999 URL: http://purl.umn.edu/15132 Dynamic and Stochastic Structures of U.S. Cotton Exports and Mill Demand AgEcon Fadiga, Mohamadou L.. This study employs a structural time-series method to model and estimate U.S. cotton exports and mill use. The results show that the stochastic process governing cotton export fluctuations is transitory, while the process pertaining to mill use has transitory, seasonal, and secular origins. The estimated structural relationships after accounting for the unobserved components indicate U.S. cotton exports respond directly to higher international price relative to domestic price of cotton, while mill use responds directly to U.S. textile output price and cotton-to-polyester price ratio. Exchange rate volatility and the U.S. Export Enhancement Program have no significant effect on cotton exports. Tipo: Journal Article Palavras-chave: Cotton exports; Cotton mill use; Kalman filter; State space; Unobserved components; Crop Production/Industries; International Relations/Trade; Production Economics; Productivity Analysis. Ano: 2006 URL: http://purl.umn.edu/57698 Common Trends, Common Cycles, and Price Relationships in the International Fiber Market AgEcon Fadiga, Mohamadou L.; Misra, Sukant K.. A multivariate unobserved component model was applied to identify common movements among cotton, wool, rayon, and polyester world prices. Two common stochastic trends and cycles govern the stochastic behaviors of price fluctuations in the world fiber market. These unobserved components have important implications as they can help in the design of more efficient commodity programs to smooth terms of trade shocks, especially in developing countries. The study found the effect of inventory adjustments on world cotton price is diminishing, which indicates that speculative behaviors in the world fiber market are less prevalent than previously thought. Tipo: Journal Article Palavras-chave: Common factors; Fiber prices; Kalman filter; State-space; Unobserved components; International Relations/Trade. Ano: 2007 URL: http://purl.umn.edu/8596 Food Scares and Demand Recovery Patterns: An Econometric Investigation AgEcon Mazzocchi, Mario. This paper aims to propose a flexible stochastic approach to measure the time pattern of a food scare, which does not require the inclusion of additional explanatory variables such as a media coverage indices and easily accommodates the reoccurrence of the same or different scares. We show the results of an application to Italian demand for beef and chicken, which has been affected by the BSE and dioxin scares over the last decade. Tipo: Conference Paper or Presentation Palavras-chave: Demand analysis; Food scare; BSE; Almost Ideal Demand System; Kalman filter; Food Consumption/Nutrition/Food Safety. Ano: 2004 URL: http://purl.umn.edu/24990 State-space approach to evaluate the relation between soil physical and chemical properties Rev. Bras. Ciênc. Solo Timm,L. C.; Reichardt,K.; Oliveira,J. C. M.; Cassaro,F. A. M.; Tominaga,T. T.; Bacchi,O. O. S.; Dourado-Neto,D.; Nielsen,D. R.. The state-space approach is used to evaluate the relation between soil physical and chemical properties in an area cultivated with sugarcane. The experiment was carried out on a Rhodic Kandiudalf in Piracicaba, State of São Paulo, Brazil. Sugarcane was planted on an area of 0.21 ha i.e., in 15 rows 100 m long, spaced 1.4 m. Soil water content, soil organic matter, clay content and aggregate stability were sampled along a transect of 84 points, meter by meter. The state-space approach is used to evaluate how the soil water content is affected by itself and by soil organic matter, clay content, and aggregate stability of neighboring locations, in different combinations, aiming to contribute to a better understanding of the relation among these variables in... Tipo: Info:eu-repo/semantics/article Palavras-chave: Spatial variability; Sugarcane crop; Kalman filter; Auto-regressive model. Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832004000100005 State-space analysis of soil data: an approach based on space-varying regression models Scientia Agricola Timm,Luís Carlos; Barbosa,Emanuel Pimentel; Souza,Manoel Dornelas de; Dynia,José Flávio; Reichardt,Klaus. The assessment of the relationship among soil properties (such as total nitrogen and organic carbon) taken along lines called transects is a subject of great interest in agricultural experimentation. This question has been usually approached through standard state-space methods by some authors in the soil science literature. Important limitations of the mentioned procedures used in practice are pointed out and discussed in this paper, specially those related to the model parameters, meaning and practical interpretation. In the standard state-space approach, based on an autoregressive structure, it does not present any parameters that express the variables relationship at the same point in space, but only at lagged points. Also, its model parameters (in the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Dynamic regression; Soil properties; Spatial heterogeneity; Kalman filter. Ano: 2003 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000200023 Registros recuperados: 17 Primeira ... 1 ... Última

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