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9262. Spectral characterization of multicone graphs
- Creator:
- Wang, Jianfeng, Zhao, Haixing, and Huang, Qiongxiang
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- adjacency matrix, cospectral graph, spectral characteriztion, and multicone graph
- Language:
- English
- Description:
- A multicone graph is defined to be the join of a clique and a regular graph. Based on Zhou and Cho's result [B. Zhou, H. H. Cho, Remarks on spectral radius and Laplacian eigenvalues of a graph, Czech. Math. J. 55 (130) (2005), 781–790], the spectral characterization of multicone graphs is investigated. Particularly, we determine a necessary and sufficient condition for two multicone graphs to be cospectral graphs and investigate the structures of graphs cospectral to a multicone graph. Additionally, lower and upper bounds for the largest eigenvalue of a multicone graph are given.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9263. Spectral estimation of non-Gaussian time series
- Creator:
- Fabián , Zdeněk
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Scalar score, power spectra, processes with infinite variance, and processes with skewed distributions
- Language:
- English
- Description:
- Based on the concept of the scalar score of a probability distribution, we introduce a concept of a scalar score of time series and propose to characterize a non-Gaussian time series by spectral density of its scalar score.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9264. Spectral radius and Hamiltonicity of graphs with large minimum degree
- Creator:
- Nikiforov, Vladimir
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, Hamiltonian cycle, Hamiltonian path, minimum degree, spectral radius, 13, and 51
- Language:
- English
- Description:
- Let G be a graph of order n and λ(G) the spectral radius of its adjacency matrix. We extend some recent results on sufficient conditions for Hamiltonian paths and cycles in G. One of the main results of the paper is the following theorem Let k \geqslant 2, n \geqslant k^{3} + k + 4, and let G be a graph of order n, with minimum degree δ(G) \geqslant k. If \lambda \left( G \right) \geqslant n - k - 1, then G has a Hamiltonian cycle, unless G=K_{1}\vee (K_{n-k-1}+K_{k}) or G=K_{k}\vee (K_{n-2k}+\bar{K}_{k})., Vladimir Nikiforov., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9265. Spectral radius inequalities for positive commutators
- Creator:
- Mirosława, Zima
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- cone, positive operator, commutator, and spectral radius
- Language:
- English
- Description:
- We establish several inequalities for the spectral radius of a positive commutator of positive operators in a Banach space ordered by a normal and generating cone. The main purpose of this paper is to show that in order to prove the quasi-nilpotency of the commutator we do not have to impose any compactness condition on the operators under consideration. In this way we give a partial answer to the open problem posed in the paper by J. Bračič, R. Drnovšek, Y. B. Farforovskaya, E. L. Rabkin, J. Zemánek (2010). Inequalities involving an arbitrary commutator and a generalized commutator are also discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9266. Spectral topologies of dually residuated lattice-ordered monoids
- Creator:
- Kühr, Jan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- DRl-monoid, prime ideal, and spectru
- Language:
- English
- Description:
- Dually residuated lattice-ordered monoids (DRl-monoids for short) generalize lattice-ordered groups and include for instance also GMV -algebras (pseudo MV -algebras), a non-commutative extension of MV -algebras. In the present paper, the spectral topology of proper prime ideals is introduced and studied.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9267. Spectrum of the Laplacian in narrow tubular neighbourhoods of hypersurfaces with combined Dirichlet and Neumann boundary conditions
- Creator:
- Krejčiřík, David
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Laplacian in tubes, Dirichlet boundary condition, Neumann boundary condition, eigenvalue asymptotics, dimension reduction, quantum waveguides, and mean curvature
- Language:
- English
- Description:
- We consider the Laplacian in a domain squeezed between two parallel hypersurfaces in Euclidean spaces of any dimension, subject to Dirichlet boundary conditions on one of the hypersurfaces and Neumann boundary conditions on the other. We derive two-term asymptotics for eigenvalues in the limit when the distance between the hypersurfaces tends to zero. The asymptotics are uniform and local in the sense that the coefficients depend only on the extremal points where the ratio of the area of the Neumann boundary to the Dirichlet one is locally the biggest.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9268. Spectrum of the weighted Laplace operator in unbounded domains
- Creator:
- Filinovskiy, Alexey
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Laplace operator, multiplicative perturbation, Dirichlet problem, Friedrichs extension, purely discrete spectra, and purely continuous spectra
- Language:
- English
- Description:
- We investigate the spectral properties of the differential operator −r s∆, s ≥ 0 with the Dirichlet boundary condition in unbounded domains whose boundaries satisfy some geometrical condition. Considering this operator as a self-adjoint operator in the space with the norm ||u|| 2 L2,s(Ω) = ∫ Ω r −s |u| 2 dx, we study the structure of the spectrum with respect to the parameter s. Further we give an estimate of the rate of condensation of discrete spectra when it changes to continuous.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9269. Speech analysis of children with developmental dysphasia by Supervised SOM
- Creator:
- Tučková, Jana and Zetocha, Petr
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Self-Organizing Map, Supervised SOM, Batch Map, vowel, developmental dysphasia, and neurology
- Language:
- English
- Description:
- This study is supported by the collective project of Department of Circuit Theory in FEE-CTU in Prague and the Department of Paediatric Neurology in 2nd Faculty of Medicine of Charles University in Prague. One of the interests in paediatric neurology is a research on electroclinical syndromes area combined with speech disorders. The aim of our project is, among others, finding a connectivity between children's neurological disorders called developmental dysphasia [2], [3] and the assessment of the degree of perception and impairment of speech. From the point of view the characterisation of language, it is very complicated to determine relevant and irrelevant information about speech and to connect it with a searching target. That is why a part of the project is solved by artificial neural networks (ANNs) with using knowledge of phonetics. At first the analysis of vowels was researched using the ANN. An initial hypothesis says that developmental dysphasia can influence a shift of formant frequencies in spectral characteristics compared with the formant frequencies of healthy children. It is necessary to have a comparative voice analysis of healthy children for evaluating the degree of these modifications. Our team created the healthy and ill children's speech databases with a comparative corpus. The healthy children's speech was recorded at kindergartens and on the first level of elementary school. The ill children's speech was recorded at hospital. The children were from 4 to 10 years old. The comparative corpus, which includes isolated vowels, monosyllables and polysyllables, was compiled by neurological specialists as related to medical therapy. The same corpus was used for the comparative analysis of healthy children. Our aim is a vowel recognition and visualisation by a Supervised Self-Organizing Maps - Supervised SOMs, which represent one of the types of the ANNs with better cluster separation based on the Kohonen map, see [1]. Better cluster separation is useful for the visualisation analysis, which is easy for the current user. The Recognition Rate (RR) depends also on the knowledge of the children's voice evolution regularity related to their age and gender. Our main objective is not the highest RR, but to observe its trend. We assume that wrong mapped vowels should be one of the indicators of developmental dysphasia. The application of the Supervised SOM should prove the ability not only to discriminate healthy and ill children, but also to describe a trend of the neurological disorders with the assistance of repeated three-month recordings during a medical therapy.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
9270. Speech disorder analysis using Matching Pursuit and Kohonen Self-Organizing Maps
- Creator:
- Bártů, Marek
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Developmental dysphasia, neurology, children's speech, Matching Pursuit, Kohonen Self-Organizing Maps, and Batch Map
- Language:
- English
- Description:
- The method described in the following text was developed to analyze disordered children speech. The diagnosis of the children is developmental dysphasia. Since developmental dysphasia has impact on children's speech ability, the classification of utterances helps to determine whether treatment and medication are appropriate. The paper describes the method developed to provide classification based on utterances but without any additional demands on speech preprocessing (e.g. labeling). The method uses Matching Pursuit algorithm for speech parameterization and Kohonen Self-Organizing Maps for extraction of features from utterances. Features extracted from the utterances of healthy children are then compared to features obtained from the speech of children suffering from the illness.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public