Title Optimizavimo algoritmai daugiamatėms skalėms su miesto kvartalo atstumais ir jų lygiagretinimas /
Translation of Title Optimization algorithms for multidimensional scaling with city-block distances and their parallelization.
Authors Galiauskas, Nerijus
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Pages 36
Keywords [eng] multidimensional scaling ; city-block distances ; optimization ; parallel computing
Abstract [eng] In this dissertation, a problem related to a visualization of elements of a multidimensional data set is considered. Here, for the sake of simplicity, an element of a multidimensional data set is called a multidimensional element. There are many techniques for visualizing multidimensional elements. Multidimensional scaling (MDS) is one of them. In applying MDS, a certain real function has to be constructed and minimized. In order to construct the function, a desired distance function has to be selected. If city-block distances are selected, the problem of minimizing such a function becomes a complicated optimization problem. In this work, this complicated optimization problem is the main research problem. Here, we formulate a new optimization problem and we show that it is equivalent to the original optimization problem arising in MDS with city-block distances. Also, we propose two sequential algorithms and one parallel algorithm for the newly formulated problem. Finally, we present the results of numerical investigations of the proposed algorithms.
Dissertation Institution Vilniaus universitetas.
Type Summaries of doctoral thesis
Language Lithuanian
Publication date 2015