Métodos geoestatísticos na modelagem espacial do diâmetro médio do cristal da goethita

Uma das necessidades da agricultura de precisão é avaliar a qualidade dos mapas dos atributos dos solos. Neste sentido, o presente trabalho objetivou avaliar o desempenho dos métodos geoestatísticos: krigagem ordinária e simulação sequencial gaussiana na predição espacial do diâmetro médio do cristal da goethita com 121 pontos amostrados em uma malha de 1 ha com espaçamentos regulares de 10 em 10 m. Após a análise textural e da concentração dos óxidos de ferro, calcularam-se os valores do diâmetro médio do cristal da goethita os quais foram analisados pela estatística descritiva e geoestatística; em seguida, foram utilizadas a krigagem ordinária e a simulação sequencial gaussiana. Com os resultados avaliou-se qual foi o método mais fiel para reproduzir as estatísticas, a função de densidade de probabilidade acumulada condicional e a estatística epsilon εy da amostra. As estimativas E-Type foram semelhantes à krigagem ordinária devido à minimização da variância. No entanto, a krigagem deixa de apresentar, em locais específicos, o grau de cristalinidade da goethita enquanto o mapa E-Type indicou que a simulação sequencial gaussiana deve ser utilizada ao invés de mapas de krigagem. Os mapas E-type devem ser preferíveis por apresentar melhor desempenho na modelagem.

Modelagem geoestatística das incertezas da distribuição espacial do fósforo disponível no solo, em área de cana-de-açúcar

Phosphorus is one of the limiting nutrients for sugarcane development in Brazilian soils. The spatial variability of this nutrient is great, defined by the properties that control its adsorption and desorption reactions. Spatial estimates to characterize this variability are based on geostatistical interpolation. However, inherent uncertainties in the procedure of these estimates are related to the variability structure of the property under study and the sample configuration of the area. Thus, the assessment of the uncertainty of estimates associated with the spatial distribution of available P (Plabile) is decisive to optimize the use of phosphate fertilizers. The purpose of this study was to evaluate the performance of sequential Gaussian simulation (sGs) and ordinary kriging (OK) in the modeling of uncertainty in available P estimates. A sampling grid with 626 points was established in a 200-ha experimental sugarcane field in Tabapuã, São Paulo State. The sGs algorithm generated 200 realizations. The sGs realizations reproduced the statistics and the distribution of the sample data. The G statistic (0.81) indicated good agreement between the values of simulated and observed fractions. The sGs realizations preserved the spatial variability of Plabile without the smoothing effect of the OK map. The accuracy in the reproduction of the variogram of the sample data obtained by the sGs realizations was on average 240 times higher than that obtained by OK. The uncertainty map, obtained by OK, showed less variation in the study area than that obtained by sGs. Thus, the evaluation of uncertainties by sGs was more informative and can be used to define and delimit specific management areas more precisely.

Desenvolvimento de uma plataforma de software para a modelagem digital de terrenos baseada em TIN

Topographical surfaces can be represented with a good degree of accuracy by means of maps. However these are not always the best tools for the understanding of more complex reliefs. In this sense, the greatest contribution of this work is to specify and to implement the architecture of an opensource software system capable of representing TIN (Triangular Irregular Network) based digital terrain models. The system implementation follows the object oriented programming and generic paradigms enabling the integration of various opensource tools such as GDAL, OGR, OpenGL, OpenSceneGraph and Qt. Furthermore, the representation core of the system has the ability to work with multiple topological data structures from which can be extracted, in constant time, all the connectivity relations between the entities vertices, edges and faces existing in a planar triangulation what helps enormously the implementation for real time applications. This is an important capability, for example, in the use of laser survey data (Lidar, ALS, TLS), allowing for the generation of triangular mesh models in the order of millions of points.

Evolução geomórfica e modelagem termocinemática 3D da região do planalto de Poços de Caldas (SP/MG)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Intervenção ergonômica e o uso da simulação computacional na concepção de produtos: o design de uma plantadora mecanizada de mandioca

Pós-graduação em Design - FAAC

Modelagem dinâmica temporal para a avaliação da disponibilidade hídrica e seus efeitos na sustentabilidade do sistema da sub-bacia do córrego do Boi Branco - SP

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Aplicação de modelagem hidrológica associada à análise geoespacial, para caracterização da vazão na micro Central Hidroelétrica Ilha Anchieta - SP

Pós-graduação em Engenharia Mecânica - FEG

Estudo dos impactos do corte seletivo de árvores na diversidade genética e demografia de população de araucaria angustifolia, utilizando modelagem ecogene

Pós-graduação em Agronomia - FEIS

Modelagem IEEE 1815 DNP3 em VHDL e análise de comunicação SG via IEEE 802.15.4 e IEEE 802.11

Pós-graduação em Engenharia Elétrica - FEIS

Modelagem generalizada do problema de planejamento da expansão de sistemas de transmissão

Pós-graduação em Engenharia Elétrica - FEIS

Otimização combinatória para alocação de fontes renováveis em microrredes de corrente contínua

Pós-graduação em Engenharia Elétrica - FEIS

Estimativa da produtividade de trigo em função da adubação nitrogenada utilizando modelagem neuro fuzzy

Currently new techniques for data processing, such as neural networks, fuzzy logic and hybrid systems are used to develop predictive models of complex systems and to estimate the desired parameters. In this article the use of an adaptive neuro fuzzy inference system was investigated to estimate the productivity of wheat, using a database of combination of the following treatments: five N doses (0, 50, 100, 150 and 200 kg ha(-1)), three sources (Entec, ammonium sulfate and urea), two application times of N (at sowing or at side-dressing) and two wheat cultivars (IAC 370 and E21), that were evaluated during two years in Selviria, Mato Grosso do Sul, Brazil. Through the input and output data, the system of adaptive neuro fuzzy inference learns, and then can estimate a new value of wheat yield with different N doses. The productivity prediciton error of wheat in function of five N doses, using a neuro fuzzy system, was smaller than that one obtained with a quadratic approximation. The results show that the neuro fuzzy system is a viable prediction model for estimating the wheat yield in function of N doses.

Transformação de coordenadas com modelagem de distorções entre SAD69 e SIRGAS2000 com o uso de Thin-Plate Splines

Several countries have been passed by change processes in their fundamental geodesic structure with the focus on the adoption of geocentric reference systems. In Brazil, the adoption of the SIRGAS2000 evolves the coexistence of two realizations from the COrrego Alegre system, two realizations from the SAD69 system and one realization from the SIRGAS2000 system. To make use of products in the old reference systems, methods of coordinate transformation between the existent reference frames are necessary. So, in this paper one solution for the transformation between coordinates from different reference frames, based on Thin-Plate Splines (TPS), that allows the estimation of parameters from one linear transformation and also one non-linear model is presented. The TPS model was developed to work with tridimensional coordinates and in this paper the results and analysis are performed with simulated data and also with data from the official Brazilian Geodetic System (SGB). In the check points from SAD69 stations (realization of 1996 - SAD69/96), the values of RMSE obtained were of 78,2 mm in latitude and 67,5 mm in longitude, before the transformation to the SIRGAS2000. In the comparison between the TPS model and ProGriD (Brazilian software provided by IBGE), the statistical indicators were reduced in 97%, by using the TPS model. Based in the obtained results from real dataset, the TPS model appears to be promising, since it allows improving the quality of transformation process with simultaneous distortion modeling.

Modelagem da área foliar de duas cultivares de amendoim em função das dimensões lineares dos folíolos

The purpose of this study was to determine a shape factor to estimate area of leaflets of two peanut cultivars (IAC TATU ST, IAC RUNNER 886). Correlation studies were conducted involving real leaf area (Sf) and leaf length (C), maximum leaf width (L) and the product between C and L. For each cultivar was determined a form factor (f) by means of regression analysis between the product of the length by the width and the actual area of leaves and the correlation between leaf area estimated by the correction factor and direct measurement. All evaluated models (linear, exponential or geometric) provided good estimates of leaf area (above 87%). Linear models had the best fit, passing or not through the origin. From a practical viewpoint, it is suggested to use the linear model involving the C and L product, using a linear coefficient equal to zero, with values of factor f equal to 0.7111 and 0.7266 for IAC RUNNER 886 and IAC TATU ST, respectively. The method of dimensions is feasible for the estimation of leaf area for both peanut cultivars, for showing good r(2) values (0.97), with errors below 3%, even when used with independent data.

Modelagem fotogramétrica e calibração de um sistema de visão omnidirecional

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)