Estimation using spatially distributed multivariate data: An example with coal quality

Modeling and Exploring Multivariate Spatial Variation: A Test Procedure for Isotropy of Multivariate Spatial Data

“…In Davis and Greenes (1983) PCA is applied to the sample correlation matrix in order to produce cokriging results by computing a series of univariate variograms on à`w eight'' matrix, whose rows are uncorrelated, their purpose being to provide an orthogonal basis for the variables, so that orthogonality holds spatially as well as at each considered location. In Di Bella and JonaLasinio (1996 and references therein) some ordination methods in which the spatial information is included are described, most of them oriented to pattern recognition in botanical studies, where great attention is given to the possible a posteriori reconsideration of the dimension of sample units through the detection of the real scale of the data.…”

Optimum and robust 3D facies interpolation strategies in a heterogeneous coal zone (Tertiary As Pontes basin, NW Spain)

“…Many efforts have been devoted to the assessment of coal resources through 2D interpolations, either by using thickness maps (Starks et al, 1982;Journel and Rossi, 1989;Schuenemeyer and Power, 2000;Hohn and McDowell 2001;Tercan and Karyigit, 2001) or percentage maps showing distribution of coal quality properties (Davis and Greenes, 1983;Bancroft and Hobbs, 1986;Watson et al, 2001;Turner and Richardson, 2004). Such approaches provide useful predictions when dealing with homogeneous coal seams, as well as for the general assessment of reserves.…”

Ichthyofauna of the Sumidouro system, state of Minas Gerais, Brazil

“…In the last scenario, we considered lost due to the exotic fish introduction all the lost species that do not depend on the communication between the lake and the river to complete their life cycle. These four scenarios and the fishes from the Sumidouro system were compared through a Cluster analysis based on the similarity index of Sorensen, UPGMA grouping (Davis and Greenes 1983). Identification of the sampled fishes in the Sumidouro system was based on Britski et al (1988).…”