10,998 research outputs found

    On the C*-algebra Generated by Toeplitz Operators and Fourier Multipliers on the Hardy Space of a Locally Compact Group

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    Let GG be a locally compact abelian Hausdorff topological group which is non-compact and whose Pontryagin dual Γ\Gamma is partially ordered. Let Γ+⊂Γ\Gamma^{+}\subset\Gamma be the semigroup of positive elements in Γ\Gamma. The Hardy space H2(G)H^{2}(G) is the closed subspace of L2(G)L^{2}(G) consisting of functions whose Fourier transforms are supported on Γ+\Gamma^{+}. In this paper we consider the C*-algebra C∗(T(G)∪F(C(Γ+˙)))C^{*}(\mathcal{T}(G)\cup F(C(\dot{\Gamma^{+}}))) generated by Toeplitz operators with continuous symbols on GG which vanish at infinity and Fourier multipliers with symbols which are continuous on one point compactification of Γ+\Gamma^{+} on the Hilbert-Hardy space H2(G)H^{2}(G). We characterize the character space of this C*-algebra using a theorem of Power.Comment: 11 page

    Essential Spectra of Quasi-parabolic Composition Operators on Hardy Spaces of the Poly-disc

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    This work is a generalization of the results in [Gul] to bi-disc case. As in [Gul], quasi-parabolic composition operators on the Hilbert-Hardy space of the bi-disc are written as a linear combination of Toeplitz operators and Fourier multipliers. The C*-algebra generated by Toeplitz operators and Fourier multipliers on the Hilbert-Hardy space of the bi-disc is written as the tensor product of the similar C*-algebra in one variable with itself. As a result we find a nontrivial set lying inside the essential spectra of quasi-parabolic composition operators

    Determination of the perceptions of sports managers about sport concept: A metaphor analysis study

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    The aim of this research is to determine the perceptions of sport managers in Turkey on the concept of sport by means of metaphors. 74 sport managers participated in the research. Phenomenology, one of the qualitative research methods, was used in the research. Content analysis method was used for the data analysis. Evaluation of the data showed that sports managers produced a total of 50 metaphors. These metaphors produced were collected in 6 different categories. As a result, it was determined that sport managers expressed the concept of sport by means of metaphors in a very rich and diverse perspective. Therefore, the metaphors determined in this study may lead the sport managers and candidates responsible for the administration of sports services and activities in terms of offering a different perspective on the practice of sport management. © 2018, Sciedu Press. All rights reserved

    Functional classification of G-Protein coupled receptors, based on their specific ligand coupling patterns

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    Functional identification of G-Protein Coupled Receptors (GPCRs) is one of the current focus areas of pharmaceutical research. Although thousands of GPCR sequences are known, many of them re- main as orphan sequences (the activating ligand is unknown). Therefore, classification methods for automated characterization of orphan GPCRs are imperative. In this study, for predicting Level 2 subfamilies of Amine GPCRs, a novel method for obtaining fixed-length feature vectors, based on the existence of activating ligand specific patterns, has been developed and utilized for a Support Vector Machine (SVM)-based classification. Exploiting the fact that there is a non-promiscuous relationship between the specific binding of GPCRs into their ligands and their functional classification, our method classifies Level 2 subfamilies of Amine GPCRs with a high predictive accuracy of 97.02% in a ten-fold cross validation test. The presented machine learning approach, bridges the gulf between the excess amount of GPCR sequence data and their poor functional characterization
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