101 research outputs found

    Audio to score alignment of folk music

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    The thesis deals with the problem of audio to score alignment of folk music. Our goal is to adapt standard methods for audio to score alignment for aligning folk music. Alignment algorithms are then used for querying music in folk music archives. In folk music, the quality of recordings is often poor, due to recording conditions, and because singers are often not professionals. This makes alignment with standard approaches difficult. In our master thesis we develop new approaches to improve alignment in folk music archives by exploiting the characteristics of folk music, such as its tone distribution. We test our algorithms on slovenian folk music and show that we achieve improvement over standard methods

    Audio to score alignment of folk music

    Get PDF
    The thesis deals with the problem of audio to score alignment of folk music. Our goal is to adapt standard methods for audio to score alignment for aligning folk music. Alignment algorithms are then used for querying music in folk music archives. In folk music, the quality of recordings is often poor, due to recording conditions, and because singers are often not professionals. This makes alignment with standard approaches difficult. In our master thesis we develop new approaches to improve alignment in folk music archives by exploiting the characteristics of folk music, such as its tone distribution. We test our algorithms on slovenian folk music and show that we achieve improvement over standard methods

    Numerical Study of Membrane Configurations

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    We studied biological membranes of spherical topology within the framework of the spontaneous curvature model. Both Monte Carlo simulations and the numerical minimization of the curvature energy were used to obtain the shapes of the vesicles. The shapes of the vesicles and their energy were calculated for different values of the reduced volume. The vesicles which exhibit in-plane ordering were also studied. Minimal models have been developed in order to study the orientational ordering in colloids coated with a thin sheet of nematic liquid crystal (nematic shells). The topological defects are always present on the surfaces with the topology of a sphere. The location of the topological defects depends strongly on the curvature of the surface. We studied the nematic ordering and the formation of topological defects on vesicles obtained by the minimization of the spontaneous curvature energy

    Order reconstruction patterns in nematic liquid crystal wells

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    We numerically study structural transitions inside shallow sub-micrometre scale wells with square cross section, filled with nematic liquid crystal material. We model the wells within the Landau–de Gennes theory. We obtain two qualitatively different states: (i) the diagonal state with defects for relatively large wells with lateral dimension greater than a critical threshold and (ii) a new, two-dimensional star-like biaxial order reconstruction pattern called the well order-reconstruction structure (WORS), for wells smaller than the critical threshold. The WORS is defined by an uniaxial cross connecting the four vertices of the square cross section. We numerically compute the critical threshold in terms of the bare biaxial correlation length and study its dependence on the temperature and on the anchoring strength on the lateral well surfaces.</jats:p

    Hysteresis in Two-Dimensional Liquid Crystal Models

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    We make a numerical study of hysteresis loop shapes within a generalized two-dimensional Random Anisotropy Nematic (RAN) model at zero temperature. The hysteresis loops appear on cycling a static external ordering field. Ordering in these systems is history dependent and involves interplay between the internal coupling constant J, the anisotropy random field D, and the ordering external field H. Here the external field is represented by a traceless tensor, analogous to extension-type fields in continuum mechanics. The calculations use both a mean field approach and full lattice simulations. Our analysis suggests the existence of two qualitatively different solutions, which we denote as symmetric and symmetry breaking. For the set of parameters explored, only the symmetric solutions are stable. Both approaches yield qualitatively similar hysteresis curves, which are manifested either by single or double loops. But the quantitative differences indicate that mean field estimates are only of limited predictive value

    The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior

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    We review the theoretical research on the influence of disorder on structure and phase behavior of condensed matter system exhibiting continuous symmetry breaking focusing on liquid crystal phase transitions. We discuss the main properties of liquid crystals as adequate systems in which several open questions with respect to the impact of disorder on universal phase and structural behavior could be explored. Main advantages of liquid crystalline materials and different experimental realizations of random field-type disorder imposed on liquid crystal phases are described
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