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considering the advantages of the genetic algorithm in comparison with the K-means algorithm, a better and more reliable answer can be obtained. In this paper, validation indices have also been used to verify the validity of the number of clusters, which aim

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considering the advantages of the genetic algorithm in comparison with the K-means algorithm, a better and more reliable answer can be obtained. In this paper, validation indices have also been used to verify the validity of the number of clusters, which aim

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Central European Geology
Authors: János Haas, Tamás Budai, István Dunkl, Éva Farics, Sándor Józsa, Szilvia Kövér, Annette E. Götz, Olga Piros, and Péter Szeitz

( Nagy et al. 1967 ) contained important observations and interpretations, which are still valid. However, a number of open questions remained since some of the problems could not be solved by the analytical methods available 50 years ago. The importance

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The uncertainty in the semivariogram has hardly been investigated in previous geostatistical studies. This paper presents an efficient methodology of uncertainty assessment based on the bootstrap. By applying this computer-intensive statistical method one can easily simulate the distribution of the empirical semivariogram estimate for each lag. The lag-wise standard errors and confidence intervals of a given level can then be easily calculated from the bootstrap replicates. These estimations are valid in any situation when classical statistics fail. The bootstrap also provides a mathematical-statistical tool to decide whether the semivariogram reaches its maximum at a given lag or not. It leads directly to a simple determination of the range of influence. Effects beyond the range, such as the hole effect, can be explored with the same approach. The empirical semivariogram, supplied by measures of uncertainty, adequately describes the true spatial behavior of the studied variable. This universal method renders the customary theoretical semivariogram models obsolete.

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Abstract

Compet-Terra is carrying out QA (Quality Assurance) services for the Hungarian Agriculture and Regional Development Agency. Quality control of the LPIS is one of the important QA duties. The LPIS data set is updated yearly according to the cycles of agricultural subsidies. Compet-Terra elaborated an Open Source Software based checking method that could be adopted by the client without the financial expense of software.

QuantumGIS (as the primary tool), gvSIG, and LibreOffice were used for the quality control of the LPIS. Four primary quality types were checked: (1) the land parcel attributes, (2) the areas of the polygons, (3) the completeness of the content and (4) the topological quality. For these investigations topological GIS functions and database management functions were used. The most important functions were topological difference calculation, polygon area calculation and geometry validity check. Complex procedures were also carried out with proprietary tools to compare the results and the run-time performances.

The result of the adoption of OSS GIS tools for LPIS checking was positive. All the planned procedures could be implemented using OSS GIS. OSS tools proved to be robust, reliable, userfriendly and performed well.

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Central European Geology
Authors: Ana Brcković, Monika Kovačević, Marko Cvetković, Iva Kolenković Močilac, David Rukavina, and Bruno Saftić

stratigraphic interval in which they are expected (e.g., Vukovar Formation). Predictions of this lithofacies are either sporadic and not geologically valid in terms of regional settings (Fig.  6a , c – breccia-conglomerates determined in formations of

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uncertainty of long-term predictions can be reduced using independent methods, with various assumptions. This research is aimed to be one of the several valid methods. Acknowledgements The author would like to express his

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%–10% a Valid for the insoluble residue b Valid for the clay fraction of the insoluble residue

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yield skewed results. This statement is even more valid in the case of such an archeological object as an earthen pyramid (kurgan, burial mound) having been piled up of soil. However, the level of elements and carbon must have changed considerably during

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lherzolites occurred by igneous refertilization, the validity and significance of the primitive mantle values based on this type of fertile mantle rock compositions become questionable ( Le Roux et al. 2007 ). It follows that carefully selected xenoliths may

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