Visualization of Multidimensional Data in Purpose of Qualitative Classification of Various Types of Coal / Wizualizacja Wielowymiarowych Danych W Celu Klasyfikacji Jakościowej Różnych Typów Węgla

Abstract

Coal as energetic raw material features by many parameters determining its quality. In classification of coal types there are many of them with typical division of energetic, semi-coking and coking coal. The data concerning coal are usually treated as independent values while this kind of approach is not always right. Authors proposed new solutions in this aspect and performed the multidimensional analysis of three selected types of coal featuring by various properties which originated from three various hard coal mines located in Upper Silesia Region. The object of the research was so-called raw coal which was not processed before. For each type of coal the detailed statistical analysis of seven chosen properties of coal was performed. To perform adequate and complete statistical analysis it is necessary to analyze the chosen properties of coal together in multidimensional way. It was decided to apply new and modern visualizing methods of multidimensional data which were observational tunnels method and parallel coordinates method. The applied methods allowed to obtain visualization of seven-dimensional data describing coal. By means of these visualizations it was possible to observe the significant division of the features space between researched types of coal. These methods allowed to look at the investigated data from various perspectives and make possible to determine significant differences between researched materials. For the investigated coals such differences were determined clearly what proved that by means of these methods it is possible to successfully identify type of coal as well to analyze in details its individual properties and identify, for example, particle size fraction etc. The obtained results are innovative and are the basis for more detailed researches taking into consideration also other coal properties, including its structure and texture. This methodology can be also applied successfully for other types of raw materials, like ores.

Multidimensional statistical and visualization methods in description of grained materials

“…It was concluded on the basis of separate areas in the space occupied by the considered size fractions, which was not obtained in examination of all 9 size fractions at the same time. A similar analysis was performed for all possible pairs, only confirming the aforementioned conclusions [9][10][11]18]. Therefore, the following charts are presented for the separated size fraction (1-3,15 mm).…”

“…A qualitative multidimensional analysis can therefore be applied using methods of data visualization, which change multidimensional features of either phenomena or material vectors into a form in which it is possible to transfer data onto either a two-or three-dimensional plane to examine certain areas of homogeneity. The results of these analyses can be helpful in characterizing grained materials, as well as in constructing mineral processing models [18]. Up until now, the methods applied to provide a visual image of multidimensional data were used to examine different problems.…”

“…The observational tunnels method makes it possible to achieve an external view of the observed multidimensional sets of points using the tunnel radius. [18].…”

“…The methodology of the observational tunnels method and the drawing procedure are accurately described elsewhere [8][9][10][11]18]. The observational tunnels method was used to analyze the data describing three types of hard coal.…”

“…Consideration of grained materials classification and identification constitutes only one of many issues which can be faced in the field of mineral processing. A number of works serve as an evidence of the widespread use of the analysis of variance and the observational tunnels method in different areas of science [4,10,11,14,[16][17][18]. However, the analysis carried out for different types of coal confirms that these methods can be successfully connected to the mineral processing.…”