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Malte Henkel - One of the best experts on this subject based on the ideXlab platform.
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From dynamical Scaling to local scale-invariance: a tutorial
Eur.Phys.J.ST, 2017Co-Authors: Malte HenkelAbstract:Dynamical Scaling arises naturally in various many-body systems far from equilibrium. After a short historical overview, the elements of possible extensions of dynamical Scaling to a local scale-invariance will be introduced. Schrödinger-invariance, the most simple example of local scale-invariance, will be introduced as a dynamical symmetry in the Edwards-Wilkinson universality class of interface growth. The Lie algebra construction, its representations and the Bargman superselection rules will be combined with non-equilibrium Janssen-de Dominicis field-theory to produce explicit predictions for responses and correlators, which can be compared to the results of explicit model studies. At the next level, the study of non-stationary states requires to go over, from Schrödinger-invariance, to ageing-invariance. The ageing algebra admits new representations, which acts as dynamical symmetries on more general equations, and imply that each non-equilibrium Scaling Operator is characterised by two distinct, independent Scaling dimensions. Tests of ageing-invariance are described, in the Glauber-Ising and spherical models of a phase-ordering ferromagnet and the Arcetri model of interface growth.
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on logarithmic extensions of local scale invariance
Nuclear Physics, 2013Co-Authors: Malte HenkelAbstract:Abstract Ageing phenomena far from equilibrium naturally present dynamical Scaling and in many situations this may be generalised to local scale-invariance. Generically, the absence of time-translation-invariance implies that each Scaling Operator is characterised by two independent Scaling dimensions. Building on analogies with logarithmic conformal invariance and logarithmic Schrodinger-invariance, this work proposes a logarithmic extension of local scale-invariance, without time-translation-invariance. Carrying this out requires in general to replace both Scaling dimensions of each Scaling Operator by Jordan cells. Co-variant two-point functions are derived for the most simple case of a two-dimensional logarithmic extension. Their form is compared to simulational data for autoresponse functions in several universality classes of non-equilibrium ageing phenomena.
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on logarithmic extensions of local scale invariance
arXiv: High Energy Physics - Theory, 2010Co-Authors: Malte HenkelAbstract:Ageing phenomena far from equilibrium naturally present dynamical Scaling and in many situations this may generalised to local scale-invariance. Generically, the absence of time-translation-invariance implies that each Scaling Operator is characterised by two independent Scaling dimensions. Building on analogies with logarithmic conformal invariance and logarithmic Schr\"odinger-invariance, this work proposes a logarithmic extension of local scale-invariance, without time-translation-invariance. Carrying this out requires in general to replace both Scaling dimensions of each Scaling Operator by Jordan cells. Co-variant two-point functions are derived for the most simple case of a two-dimensional logarithmic extension. Their form is compared to simulational data for autoresponse functions in several universality classes of non-equilibrium ageing phenomena.
Emrah Akyol - One of the best experts on this subject based on the ideXlab platform.
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ÖLÇEKLENEBİLİR VİDEO KODLAMADA İÇERİĞE BAĞLI ÖLÇEKLEME OPERATÖRÜ SEÇİMİ CONTENT- ADAPTIVE Scaling OPTION SELECTION IN SCALABLE VIDEO CODING
2005Co-Authors: Emrah AkyolAbstract:Scalable video coders provide different options, such as temporal, spatial and SNR scalability, each option results in different kinds and levels of visual distortion depending on the content. We observe that a single scalability option does not fit the whole video content well, and the scalability Operator should be varied for different temporal segments depending on the content of the segment. We propose a method to choose the best Scaling option that results in minimum visual distortion. We employ four component metrics to quantify artifacts caused by bitrate reduction, spatial size reduction and temporal subsampling, which are a flatness measure, a blockiness measure, a blurriness measure, and a jerkiness measure. We define the best Scaling Operator as the one with the minimum distortion score which is given by a linear combination of these four component measures. Two subjective tests have been performed to validate the proposed procedure for optimal selection of scalability Operators for soccer videos.
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optimum Scaling Operator selection in scalable video coding
2004Co-Authors: Emrah Akyol, Murat A Tekalp, Reha M CivanlarAbstract:Scalable video coders provide different options, such as temporal, spatial and SNR scalability, where each option results in different kinds and/or levels of visual distortion at the lower scales depending on the content and bitrate. We observe that in most cases a single scalability option does not fit the whole video content well, and the scalability Operator should be varied for different temporal segments depending on the content of the segment. In this work, assuming the video is temporally segmented by some content analysis scheme, we propose a method to choose the visually best Scaling option that results in minimum visual distortion among temporal, spatial and SNR scalability Operators for each temporal segment of soccer videos. We employ four component metrics to quantify artifacts caused by bitrate reduction, spatial size reduction and temporal subsampling, which are a flatness measure, a blockiness measure, a blurriness measure, and a temporal distortion (jerkiness) measure. We then define the best Scaling Operator for each video segment as the one with the minimum distortion score which is given by a linear combination of these four component measures. Coefficients of this linear combination are tuned to content type using a training procedure. Two subjective tests have been performed to validate the proposed distortion measures and procedure for optimal selection of scalability Operators for soccer videos.
Reha M Civanlar - One of the best experts on this subject based on the ideXlab platform.
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optimum Scaling Operator selection in scalable video coding
2004Co-Authors: Emrah Akyol, Murat A Tekalp, Reha M CivanlarAbstract:Scalable video coders provide different options, such as temporal, spatial and SNR scalability, where each option results in different kinds and/or levels of visual distortion at the lower scales depending on the content and bitrate. We observe that in most cases a single scalability option does not fit the whole video content well, and the scalability Operator should be varied for different temporal segments depending on the content of the segment. In this work, assuming the video is temporally segmented by some content analysis scheme, we propose a method to choose the visually best Scaling option that results in minimum visual distortion among temporal, spatial and SNR scalability Operators for each temporal segment of soccer videos. We employ four component metrics to quantify artifacts caused by bitrate reduction, spatial size reduction and temporal subsampling, which are a flatness measure, a blockiness measure, a blurriness measure, and a temporal distortion (jerkiness) measure. We then define the best Scaling Operator for each video segment as the one with the minimum distortion score which is given by a linear combination of these four component measures. Coefficients of this linear combination are tuned to content type using a training procedure. Two subjective tests have been performed to validate the proposed distortion measures and procedure for optimal selection of scalability Operators for soccer videos.
Murat A Tekalp - One of the best experts on this subject based on the ideXlab platform.
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optimum Scaling Operator selection in scalable video coding
2004Co-Authors: Emrah Akyol, Murat A Tekalp, Reha M CivanlarAbstract:Scalable video coders provide different options, such as temporal, spatial and SNR scalability, where each option results in different kinds and/or levels of visual distortion at the lower scales depending on the content and bitrate. We observe that in most cases a single scalability option does not fit the whole video content well, and the scalability Operator should be varied for different temporal segments depending on the content of the segment. In this work, assuming the video is temporally segmented by some content analysis scheme, we propose a method to choose the visually best Scaling option that results in minimum visual distortion among temporal, spatial and SNR scalability Operators for each temporal segment of soccer videos. We employ four component metrics to quantify artifacts caused by bitrate reduction, spatial size reduction and temporal subsampling, which are a flatness measure, a blockiness measure, a blurriness measure, and a temporal distortion (jerkiness) measure. We then define the best Scaling Operator for each video segment as the one with the minimum distortion score which is given by a linear combination of these four component measures. Coefficients of this linear combination are tuned to content type using a training procedure. Two subjective tests have been performed to validate the proposed distortion measures and procedure for optimal selection of scalability Operators for soccer videos.
Hiroshi Shirokura - One of the best experts on this subject based on the ideXlab platform.
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Modification of Matrix Models by Square Terms of Scaling Operators
arXiv: High Energy Physics - Theory, 1994Co-Authors: Hiroshi ShirokuraAbstract:We study one (or two) matrix models modified by terms of the form $g(\rho(P))^2 + g'(\rho'({\cal{O}}))^2$, where the matrix representation of the puncture Operator $P$ and the one of a Scaling Operator ${\cal{O}}$ are denoted by $\rho(P)$ and $\rho'({\cal{O}})$ respectively. We rewrite the modified models as effective theories of baby universes. We find an upper bound for the gravitational dimension of ${\cal{O}}$ under which we can fine tune the coupling constants to obtain new critical behaviors in the continuum limit. The simultaneous tuning of $g$ and $g'$ is possible if the representations $\rho(P)$ and $\rho'({\cal{O}})$ are chosen so that the non-diagonal elements of the mass matrix of the effective theory vanish.
