Wszystkie pola: spectral property - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: A spectral synthesis property for \(C_b(X, \Beta)\)
Autorzy:: Arizmendi-Peimbert, H.
Carrillo-Hoyo, A.
Garcı́a, A.
Powiązania:: https://bibliotekanauki.pl/articles/745757.pdf
Data publikacji:: 2008
Wydawca:: Polskie Towarzystwo Matematyczne
Tematy:: spectral synthesis
strict topology
closed ideals
topological divisors of zero
Opis:: Let \((C_b (X) , \Beta)\) be the algebra of all continuous bounded real or complex valued functions defined on a completely regular Hausdorff space \(X\) with the usual algebraic operations and with the strict topology \(\Beta\). It is proved that \((C_b (X) , \Beta)\) has a spectral synthesis, i.e. every of its closed ideals is an intersection of closed maximal ideals of codimension 1. We give one necessary and two sufficient conditions over \(X\) in order that \((C_b (X) , \Beta)\) has no proper non-zero closed principal ideals. Moreover if \(X\) satisfy any of these two conditions and is also a k-space, then any non zero element of \(C_b(X)\) is invertible or a topological divisor of zero.
Źródło:: Commentationes Mathematicae; 2008, 48, 2
0373-8299
Pojawia się w:: Commentationes Mathematicae
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Falseness of the finiteness property of the spectral subradius
Autorzy:: Czornik, A.
Jurgaś, P.
Powiązania:: https://bibliotekanauki.pl/articles/929601.pdf
Data publikacji:: 2007
Wydawca:: Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:: właściwość skończoności
podpromień spektralny
finiteness property
spectral subradius
Opis:: We prove that there exist infinitely may values of the real parameter α for which the exact value of the spectral subradius of the set of two matrices (one matrix with ones above and on the diagonal and zeros elsewhere, and one matrix with α below and on the diagonal and zeros elsewhere, both matrices having two rows and two columns) cannot be calculated in a finite number of steps. Our proof uses only elementary facts from the theory of formal languages and from linear algebra, but it is not constructive because we do not show any explicit value of α that has described property. The problem of finding such values is still open.
Źródło:: International Journal of Applied Mathematics and Computer Science; 2007, 17, 2; 173-178
1641-876X
2083-8492
Pojawia się w:: International Journal of Applied Mathematics and Computer Science
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Soil colour and spectral analysis employing linear regression models. I. Effect of organic matter
Autorzy:: Barouchas, P.E.
Moustakas, N.K.
Powiązania:: https://bibliotekanauki.pl/articles/26488.pdf
Data publikacji:: 2004
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: organic matter
soil colour
spectral analysis
soil property
colour
Źródło:: International Agrophysics; 2004, 18, 1
0236-8722
Pojawia się w:: International Agrophysics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: On a property of weak resolvents and its application to a spectral problem
Autorzy:: Uetake, Yoichi
Powiązania:: https://bibliotekanauki.pl/articles/1294816.pdf
Data publikacji:: 1997
Wydawca:: Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:: weak resolvent
cyclic vector
spectral radius
Hardy class
operator model theory
scattering theory
control theory
Opis:: We show that the poles of a resolvent coincide with the poles of its weak resolvent up to their orders, for operators on Hilbert space which have some cyclic properties. Using this, we show that a theorem similar to the Mlak theorem holds under milder conditions, if a given operator and its adjoint have cyclic vectors.
Źródło:: Annales Polonici Mathematici; 1997, 66, 1; 263-268
0066-2216
Pojawia się w:: Annales Polonici Mathematici
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Spectral dependence of the correlation between the backscattering coefficient and the volume scattering function measured in the Southern Baltic Sea
Autorzy:: Freda, W.
Powiązania:: https://bibliotekanauki.pl/articles/47893.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: volume scattering function
backscattering coefficient
marine optics
Baltic Sea
optical property
sea water
spectral variability
Opis:: Direct measurements of the backscattering coefficient bb require the determination of the Volume Scattering Function (VSF) and its integration over a backward hemisphere. In sea water they are difficult and are therefore carried out very rarely. That is why the backscattering coefficient is much more frequently obtained with so-called single angle scattering meters: these operate by measuring the VSF for a fixed angle region of the backward hemisphere. This article examines the spectral variability of the correlation between directly measured backscattering coefficients and VSFs. Also presented are the averaged slopes of VSF spectra, measured in southern Baltic waters over a wide range of scattering angles.
Źródło:: Oceanologia; 2012, 54, 3
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Spectral light absorption by yellow substance in the Kattegat-Skagerrak area
Autorzy:: Hojerslev, N.K.
Aas, E.
Powiązania:: https://bibliotekanauki.pl/articles/48244.pdf
Data publikacji:: 2001
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: yellow substance
wavelength
spectral slope
coastal water
Kattegat area
absorption coefficient
Scandinavian fjord
Baltic Sea
optical property
Skagerrak area
light absorption
Opis:: More than 1500 water samples were taken from the Kattegat, the Skagerrak and adjacent waters. The value of the absorption coefficient of yellow substance at 310 nm was found to varyf rom 0.06 to 7.4 m−1 in the open coastal waters, with a mean value of 1.3 m−1. The corresponding wavelength-averaged value (250–450 nm) of the semilogarithmic spectral slope of the coefficient ranges from 0.008 to 0.042 nm−1, and the mean value is 0.023 nm−1. Closer to river discharges, as in the fjords, the values of the slope seem to be more constant at around 0.0175±0.0015 nm−1. In this area the slope must then be known in order to compare absorption at different wavelengths or to model the yellow substance absorption.
Źródło:: Oceanologia; 2001, 43, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Spectral effects in bio-optical control on the ocean system
Autorzy:: Sathyendranath, S.
Platt, T.
Powiązania:: https://bibliotekanauki.pl/articles/47462.pdf
Data publikacji:: 2007
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: primary production
ocean colour
bio-optical property
remote sensing
ocean ecosystem
phytoplankton
Opis:: The influence of phytoplankton on the spectral structure of the submarine irradiance field is reviewed. The implications for the ocean system of the spectral response by phytoplankton to the ambient light field are discussed. For example, it provides the basis for retrieval of phytoplankton biomass by visible spectral radiometry (ocean-colour remote sensing). In the computation of primary production, the results of spectral models differ in a known and systematic manner from those of non-spectral ones. The bias can be corrected without risk of incurring additional random errors. The models in use for phytoplankton growth, whether based on available light or absorbed light, whether expressed in terms of chlorophyll or carbon, are shown all to conform to the same basic formalism with the same parameters. Residual uncertainty lies less with the models than with the parameters required for their implementation. The submarine light field and the spectral characteristics of phytoplankton carry latent information on phytoplankton community structure. Differences in spectral response by different functional types of phytoplankton are small but significant. Optical considerations limit the maximum phytoplankton biomass that can be sustained in a given surface mixed layer. Moreover, the upper bound on the biomass depends on the spectral response of the dominant phytoplankton taxa. As a result, an optical control exists in the mixed layer that tends to resist extreme excursions of the biomass and also to maintain biodiversity in the phytoplankton.
Źródło:: Oceanologia; 2007, 49, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Wavelets for time series analysis - a survey and new results
Autorzy:: Mielniczuk, J.
Wojdyłło, P.
Powiązania:: https://bibliotekanauki.pl/articles/970989.pdf
Data publikacji:: 2005
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: long-range dependence
decorrelation property
spectral density
time series
wavelets
fractional Gaussian noise (FGN)
fractional autoregressive integrated moving average (FARIMA)
Hurst exponent
falka
Opis:: In the paper we review stochastic properties of wavelet coefficients for time series indexed by continuous or discrete time. The main emphasis is on decorrelation property and its implications for data analysis. Some new properties are developed as the rates of correlation decay for the wavelet coefficients in the case of long-range dependent processes such as the fractional Gaussian noise and the fractional autoregressive integrated moving average processes. It is proved that for such processes the within-scale covariance of the wavelet coefficients at lag k is O(k^2(H-N)-2), where H is the Hurst exponent and N is the number of vanishing moments of the wavelet employed. Some applications of decorrelation property are briefly discussed.
Źródło:: Control and Cybernetics; 2005, 34, 4; 1093-1125
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki