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Tytuł:
State estimation based on Generalized Gaussian distributions
Autorzy:
Li, X.
Xie, Y.
Powiązania:
https://bibliotekanauki.pl/articles/220888.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Generalized Gaussian distributions
state estimation
Gaussian particle pilter
nonlinear systems
Opis:
This paper presents a novel strategy of particle filtering for state estimation based on Generalized Gaussian distributions (GGDs). The proposed strategy is implemented with the Gaussian particle pilter (GPF), which has been proved to be a powerful approach for state estimation of nonlinear systems with high accuracy and low computational cost. In our investigations, the distribution which gives the complete statistical characterization of the given data is obtained by exponent parameter estimation for GGDs, which has been solved by many methods. Based on GGDs, an extension of GPF is proposed and the simulation results show that the extension of GPF has higher estimation accuracy and nearly equal computational cost compared with the GPF which is based on Gaussian distribution assumption.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 65-76
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust estimation and its application to a classification problem
Estymacja odporna i jej zastosowanie w pewnym problemie klasyfikacji
Autorzy:
Gacki, Henryk
Kulawik, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/953453.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
gaussian classier
klasykator gaussowski
Opis:
W artykule omówiono problem klasyfikacji dla dwóch klas w przypadku przyjęcia założenia, że rozkłady cech w klasach są wielowymiarowymi rozkładami normalnymi. Problem rozwiązano za pomocą empirycznego klasyfikatora gaussowskiego i wybranych estymatorów nieznanych parametrów wielowymiarowego rozkładu normalnego. Uwzględnione zostały następujące estymatory: MLE (the maximum likelihood estimator - estymator największej wiarogodności), KZE (Kulawik-Zontek estimator) i MCDE (the minimum covariance determinant estimator). Klasyfikatory oparte o MLE i KZE zostały porównane w przypadku przykładu empirycznego (mała próba). W przypadku dużych prób porównane zostały klasyfikatory oparte o trzy wspomniane estymatory.
In the article, a classification problem with two distributed classes is considered. The problem is solving using empirical discriminant functions for Gaussian classifier and estimators for unknown parameters of multivariate normal distribution. The three etimators, maximum likelihood estimator, Kulawik-Zontek estimator and minimum covariance determinant estimator, are compared in two different empirical examples (small size sample and large size sample).
Źródło:
Mathematica Applicanda; 2019, 47, 2
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Gaussian measure on algebraic varieties
Autorzy:
Agricola, Ilka
Friedrich, Thomas
Powiązania:
https://bibliotekanauki.pl/articles/1205282.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Gaussian measure
algebraic variety
Opis:
We prove that the ring ℝ[M] of all polynomials defined on a real algebraic variety $M⊂ℝ^n$ is dense in the Hilbert space $L^2(M,e^{-|x|^2}dμ)$, where dμ denotes the volume form of M and $dν = e^{-|x|^2}dμ$ the Gaussian measure on M.
Źródło:
Fundamenta Mathematicae; 1999, 159, 1; 91-98
0016-2736
Pojawia się w:
Fundamenta Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of Genetic Algorithms for Searching Parameter Space in Gaussian Process Modeling
Autorzy:
Krok, A.
Powiązania:
https://bibliotekanauki.pl/articles/308239.pdf
Data publikacji:
2015
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Gaussian processes
genetic algorithms
Opis:
The aim of the paper is to present the possibilities of modeling the experimental data by Gaussian processes. Genetic algorithms are used for finding the Gaussian process parameters. Comparison of data modeling accuracy is made according to neural networks learned by Kalman filtering. Concrete hysteresis loops obtained by the experiment of cyclic loading are considered as the real data time series.
Źródło:
Journal of Telecommunications and Information Technology; 2015, 3; 58-63
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cross-polarized normal mode patterns at a dielectric interface
Autorzy:
Nasalski, W.
Powiązania:
https://bibliotekanauki.pl/articles/199889.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reflection
refraction
normal modes
elegant beams
Hermite-Gaussian beams
Laguerre-Gaussian beams
Opis:
Basic features of narrow optical beam interactions with a dielectric interface are analysed. As it was recently shown, two types of paraxial beams – elegant Hermite-Gaussians of linear polarization and elegant Laguerre-Gaussians of circular polarization – can be treated as vector normal modes of the interface [1]. In this contribution the problem of normal modes is discussed with special attention paid for the case of beam oblique incidence. Excitation of higher-order modes by cross-polarization coupling is described and it is shown that this process critically depends on a propagation direction of the incident beam. Besides the expected changes of mode indices induced by generalised transmission and reflection matrices, the new phenomenon of optical vortex spectral splitting at the interface is revealed and off-axis spectral placements of the splitted vortices are determined. Results of numerical simulations given here for beam reflection entirely confirm theoretical predictions even for beams beyond the range of paraxial approximation.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2010, 58, 1; 141-154
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Elements in Fourier Analysis of q-Gaussian Functions
Autorzy:
Rodrigues, P S. S.
Giraldi, G. A.
Powiązania:
https://bibliotekanauki.pl/articles/375832.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
q-Gaussian kernel
signal processing
Opis:
There is a consensus in signal processing that the Gaussian kernel and its partial derivatives enable the development of robust algorithms for feature detection. Fourier analysis and convolution theory have a central role in such development. In this paper, we collect theoretical elements to follow this avenue but using the q-Gaussian kernel that is a nonextensive generalization of the Gaussian one. Firstly, we review the one-dimensional q-Gaussian and its Fourier transform. Then, we consider the two-dimensional q-Gaussian and we highlight the issues behind its analytical Fourier transform computation. In the computational experiments, we analyze the q-Gaussian kernel in the space and Fourier domains using the concepts of space window, cut-o frequency, and the Heisenberg inequality.
Źródło:
Theoretical and Applied Informatics; 2015, 27, 2; 16-44
1896-5334
Pojawia się w:
Theoretical and Applied Informatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The problem of the calculation of the frequency of diagnostic examinations based on device’s proper operation time
Autorzy:
Rudnicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/2073666.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
reliability
diagnostic
Gaussian random variable
Opis:
The paper presents the proposal to apply the normal distribution to solve the problemof the frequency of diagnostic tests. Particular emphasis is placed on simplicity of the method. This method may be useful for the average user technical system. The method reduces the number of assumptions to a minimum. The results do not raise of serious doubts but they require verification of course.
Źródło:
Journal of Polish CIMEEAC; 2015, 10, 1; 139--147
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extreme order statistics in an equally correlated Gaussian array
Autorzy:
Wiśniewski, Mateusz
Powiązania:
https://bibliotekanauki.pl/articles/1340599.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
equally correlated
Gaussian array
extreme order statistics
Opis:
This paper contains the results concerning the weak convergence of d-dimensional extreme order statistics in a Gaussian, equally correlated array. Three types of limit distributions are found and sufficient conditions for the existence of these distributions are given.
Źródło:
Applicationes Mathematicae; 1993-1995, 22, 2; 193-200
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Verification of the predictive segmentation algorithm for the laser triangulation method
Autorzy:
Reiner, J.
Stankiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/220548.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser triangulation
predictive segmentation
discrete Gaussian curvature
Opis:
Laser triangulation is one of the machine vision measurement methods most commonly used in 3D quality control. However, considering its susceptibility to interference, it cannot be used in certain areas of industrial production e.g. very shiny surfaces. Thus, for the improvement of its applicability, a predictive algorithm of light profile segmentation was designed, where - as a result of using a'priori knowledge - the method becomes resistant to secondary reflexes. The developed technique has been tested on selected parts with surfaces typical for the machine-building industry. The evaluation has been presented based on the surface representation (mapping) error analysis, using the difference between the obtained cloud of points and the nominal surface as processing data, as well as scatter of the discrete Gauss curvature.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 667-678
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Small perturbations with large effects on value-at-risk
Autorzy:
Esquível, Manuel
Dimas, Luís
Mexia, João
Didier, Philippe
Powiązania:
https://bibliotekanauki.pl/articles/729834.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Gaussian perturbation
value-at-risk
delta-normal model
Opis:
We show that in the delta-normal model there exist perturbations of the Gaussian multivariate distribution of the returns of a portfolio such that the initial marginal distributions of the returns are statistically undistinguishable from the perturbed ones and such that the perturbed V@R is close to the worst possible V@R which, under some reasonable assumptions, is the sum of the V@Rs of each of the portfolio assets.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2013, 33, 1-2; 151-169
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metric entropy of convex hulls in Hilbert spaces
Autorzy:
Li, Wenbo V.
Linde, Werner
Powiązania:
https://bibliotekanauki.pl/articles/1206124.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
metric entropy
convex hull
majorizing measure
Gaussian process
Opis:
Let T be a precompact subset of a Hilbert space. We estimate the metric entropy of co(T), the convex hull of T, by quantities originating in the theory of majorizing measures. In a similar way, estimates of the Gelfand width are provided. As an application we get upper bounds for the entropy of co(T), $T={t_1,t_2,...}$, $||t_j||≤a_j$, by functions of the $a_j$'s only. This partially answers a question raised by K. Ball and A. Pajor (cf. [1]). Our estimates turn out to be optimal in the case of slowly decreasing sequences $(a_j)_{j=1}^∞$.
Źródło:
Studia Mathematica; 2000, 139, 1; 29-45
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling spatial aspects of mobile channel for low antenna height environments
Autorzy:
Simsim, M. T.
Khan, N. M.
Rapajic, P. B.
Powiązania:
https://bibliotekanauki.pl/articles/309429.pdf
Data publikacji:
2006
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Gaussian distributions
geometric modeling
multi-path channels
scattering
Opis:
It is essential to have deep understanding of the mobile radio channel in particular for radio communication modeling and advanced technology system design. Models for the mobile radio channel are vital for the study of smart antenna systems, both for the design of algorithms, system-testing purposes, and for network planning. This paper provides an intensive study of the spatial characteristics of the mobile channel for low antenna height cellular environments, i.e., picocells and microcells, assuming Gaussian distributed scatterers. We investigate previous work on the angle of arrival (AoA) statistics for Gaussian distributed scatterers and make appropriate comments. Further, we employ the recently proposed eccentro-scattering physical channel model, as a generalized model, to derive the probability density function (pdf) of AoA of the multipaths at base station (BS) assuming Gaussian distributed scatterers around both BS and mobile station (MS). We found that the pdf of AoA at BS is directly affected by the standard deviation of the scatterers' density and the size of the scattering disc. The derived formulas, in closed form, can be used further for performance assessment of smart antennas and beamwidth design purposes.
Źródło:
Journal of Telecommunications and Information Technology; 2006, 2; 97-105
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Zinc Accumulation in Moss (Pylaisia polyantha) Growing Near Intensive Traffic Street Based on Modelling and Experimental Data
Autorzy:
Paliulis, Dainius
Powiązania:
https://bibliotekanauki.pl/articles/2069911.pdf
Data publikacji:
2021
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
zinc
moss
atomic absorption spectroscopy
Gaussian plume model
Opis:
Pylaisia polyantha moss growing near intensive traffic in Geležinis Vilkas street at Vingis Park (Vilnius) was selected as an indicator of environmental pollution. Two models were applied for the study: the Gaussian plume model – for zinc emission from automobiles calculation and mathematical model – for recalculating the zinc emission from transport to zinc concentration in moss. Moss samples were collected during spring, summer and autumn. There were no significant changes in Zn concentrations between these periods. Zn emission dispersion from pollution source was calculated only for one vehicle, in order to reach relationships between environmental conditions and dispersion of Zn emission from vehicle exhaust fumes pipe. It was detected that the concentration of Zn tends to decrease with the distance from the pollution source. It was observed that there was a strong relationship between wind speed and Zn concentration – the slower the wind speed, the higher concentration of zinc in moss.
Źródło:
Rocznik Ochrona Środowiska; 2021, 23; 198--213
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical gradient force of cosh-Gaussian with sine-azimuthal and half-space phase modulation
Autorzy:
Fu, R.
Gao, X.
Shen, H.
Xin, Q
Lu, X.
Guo, L.
Powiązania:
https://bibliotekanauki.pl/articles/173789.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical gradient force
cosh-Gaussian beams
wavefront modulation
Opis:
The optical gradient force distributions in focal plane of cosh-Gaussian beams with sine-azimuthal variation wavefront and half space phase modulation were investigated. Results show that optical gradient force distributions can be affected considerably by the phase retardation of half-space phase modulation, of a phase parameter that indicates the phase change frequency on an increasing azimuthal angle, and beam parameters in cosh terms of the incident beams. Many gradient force patterns occur, including cross-shape, multiple optical trap arrays, multiple-trap wheel, and many kinds of gradient force lines and curves. Symmetry of the whole gradient force pattern can also be altered remarkably. Above results may find wide applications in optical trapping systems.
Źródło:
Optica Applicata; 2013, 43, 4; 719-730
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization properties of Gaussian–Schell model quantization field in a turbulent marine-atmosphere
Autorzy:
Zhao, Y.
Xia, M.
Wang, Q.
Li, Y.
Hu, Z.
Sun, H.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173639.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
polarization fluctuation
Gaussian–Schell model
marine-atmosphere
Kolmogorov turbulence
Opis:
Polarization properties of Gaussian–Schell model quantization field propagating through the Kolmogorov turbulence of a marine-atmosphere channel are studied based on the degree of quantum polarization. The effective photon annihilation and creation operators of Gaussian–Schell model quantization field propagation in a marine-atmosphere are developed by making use of the extended Huygens–Fresnel integral of quantum field. The effects of the outer scale on the degree of polarization can be neglected. As the source transverse coherent width, the number of received photons, the inner scale of turbulent eddies, and the source transverse radius decrease or the re- fractive index structure parameter increases, the degree of polarization decreases. In theory, we find that the polarization fade of marine-atmosphere turbulence channels is larger than that of terrene-atmosphere turbulence channels under same transport parameters and the channel with a stronger turbulence strength will possess a larger detection area of a polarization signal, which have potentially important implications for free-space quantum key distribution.
Źródło:
Optica Applicata; 2016, 46, 3; 335-345
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamical system of optical soliton parameters for anti-cubic and generalized anti-cubic nonlinearities with super-Gaussian and super-sech pulses
Autorzy:
Ayela, Amour Marc
Edah, Gaston
Biswas, Anjan
Zhou, Qin
Yildirim, Yakup
Khan, Salam
Alzahrani, Abdullah K.
Belic, Milivoj R.
Powiązania:
https://bibliotekanauki.pl/articles/2060685.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
super-sech pulse
super-Gaussian
anti-cubic
variational approach
Opis:
The parameter dynamics of solitons, propagating through optical fibers, is emerged from the usage of variational principle. The anti-cubic nonlinearity and its generalized version are studied. This study reveals that the center position does not affect the dynamics of different parameters and only soliton power and linear momentum are conserved quantities.
Źródło:
Optica Applicata; 2022, 52, 1; 117--128
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gaussian process dynamic modeling and backstepping sliding mode control for magnetic levitation system of maglev train
Autorzy:
Sun, Yougang
Wang, Sumei
Lu, Yang
Xu, Junqi
Powiązania:
https://bibliotekanauki.pl/articles/2086959.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
maglev train
Gaussian process
sliding mode control
parameter perturbations
Opis:
The maglev trains are strongly nonlinear and open-loop unstable systems with external disturbances and parameters uncertainty. In this paper, the Gaussian process method is utilized to get the dynamic parameters, and a backstepping sliding mode controller is proposed for magnetic levitation systems (MLS) of maglev trains. That is, for a MLS of a maglev train, a nonlinear dynamic model with accurate parameters is obtained by the Gaussian process regression method, based on which a novel robust control algorithm is designed. Specifically, the MLS is divided into two sub-systems by a backstepping method. The inter virtual control inputs and the Lyapunov function are constructed in the first sub-system. For the second sub-system, the sliding mode surface is constructed to fulfil the design of the whole controller to asymptotically regulate the airgap to a desired trajectory. The stability of the proposed control method is analyzed by the Lyapunov method. Both simulation and experimental results are included to illustrate the superior performance of the presented method to cope with parameters perturbations and external disturbance.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 49--62
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unequally Spaced Antenna Array Synthesis Using Accelerating Gaussian Mutated Cat Swarm Optimization
Autorzy:
Kumar, Prasanna K.
Pappula, Lakshman
Madhav, B. T. P.
Prabhakar, V. S. V.
Powiązania:
https://bibliotekanauki.pl/articles/2058505.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Gaussian mutation
cat swarm optimization
linear antenna array
PSLL
Opis:
Low peak sidelobe level (PSLL) and antenna arrays with high directivity are needed nowadays for reliable wireless communication systems. Controlling the PSLL is a major is sue in designing effective antenna array systems. In this paper, a nature inspired technique, namely accelerating Gaussian mutated cat swarm optimization (AGMCSO) that attributes global search abilities, is proposed to control PSLL in the radiation pattern. In AGM-SCO, Gaussian mutation with an acceleration parameter is used in the position-updated equa tion, which allows the algorithm to search in a systematic way to prevent premature convergence and to enhance the speed of convergence. Experiments concerning several benchmark multimodal problems have been conducted and the obtained results illustrate that AGMCSO shows excellent performance concerning evolutionary speed and accuracy. To validate the overall efficacy of the algorithm, a sensitivity analysis was per formed for different AGMCSO parameters. AGMCSO was researched on numerous linear, unequally spaced antenna ar rays and the results show that in terms of generating low PSLL with a narrow first null beamwidth (FNBW), AGMCSO out performs conventional algorithms.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 1; 99--109
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtration of digital signals using wavelets
Autorzy:
Łuczak, D.
Skrzypiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/376402.pdf
Data publikacji:
2016
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
wavelet transform
on-line filtering
Gaussian noise
digital signal
Opis:
The article constitutes a set of research referring to the removal of the noise of Gaussian distribution of signal using wavelet analysis. The thesis has been launched of presentation of existing analysis algorithms, starting of discrete transform related to Mallat’s algorithm, and ending with the selected methods on inverse wavelet transform. The task was carried out by using the simulation scripts of package Wavelet Toolbox in MATLAB. The studies of using on-line filtering algorithms has been undergone. The delay value, which was implemented by the various filtration methods, was determined through simulations. The inclusion of the comparison of results allows to evaluate the quality of filtration.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2016, 85; 187-195
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two methods for determination of the effective wavenumber of Gaussian beams in absolute gravimeters
Autorzy:
Křen, P.
Pálinkáš, V.
Powiązania:
https://bibliotekanauki.pl/articles/220517.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diffraction correction
effective wavenumber
interferometer
Gaussian beam
absolute gravimeter
Opis:
This paper presents two methods for evaluation of the effective wavenumber of nearly-Gaussian beams in laser interferometers that can be used for determination of a so called diffraction correction in absolute gravimeters. The first method, that can be simply used in situ, is an empirical procedure based on the evaluation of the variability of g measurements against the amount of light limited by an iris diaphragm and transmitted to a photodetector. However, precision of this method depends on the beam quality similarly as in the case of the conventional method based on measurement of a beam width. The second method, that is more complex, is based on beam profiling in various distances and on calculation of the effective wavenumber using the second spatial derivative of a non-ideal beam field envelope. The measurement results achieved by both methods are presented on an example of two absolute gravimeters and the determined diffraction corrections are compared with the results obtained by measurements of beam width. Agreement of methods within about 1 μGal have been obtained with average diffraction corrections slightly exceeding +2 μGal for three FG5(X) gravimeter configurations.
Źródło:
Metrology and Measurement Systems; 2018, 25, 4; 701-713
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The higher order Riesz transform for Gaussian measure need not be of weak type (1,1)
Autorzy:
Forzani, Liliana
Scotto, Roberto
Powiązania:
https://bibliotekanauki.pl/articles/1217692.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Fourier analysis
Gaussian measure
Poisson-Hermite integrals
Hermite expansions
Opis:
The purpose of this paper is to prove that the higher order Riesz transform for Gaussian measure associated with the Ornstein-Uhlenbeck differential operator $L:= d^2//dx^2 - 2xd//dx$, x ∈ ℝ, need not be of weak type (1,1). A function in $L^1(dγ)$, where dγ is the Gaussian measure, is given such that the distribution function of the higher order Riesz transform decays more slowly than C/λ.
Źródło:
Studia Mathematica; 1998, 131, 3; 205-214
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Optimal Threshold Value and Number of Keypoints in Scale Invariant Feature Transform-based Copy-Move Forgery Detection
Autorzy:
Isnanto, R. Rizal
Zahra, Ajub Ajulian
Santoso, Imam
Lubis, Muhammad Salman
Powiązania:
https://bibliotekanauki.pl/articles/227299.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
forgery
Gaussian noise
feature extraction
pattern matching
Euclidean distance
Opis:
The copy-move forgery detection (CMFD) begins with the preprocessing until the image is ready to process. Then, the image features are extracted using a feature-transform-based extraction called the scale-invariant feature transform (SIFT). The last step is features matching using Generalized 2 Nearest-Neighbor (G2NN) method with threshold values variation. The problem is what is the optimal threshold value and number of keypoints so that copy-move detection has the highest accuracy. The optimal threshold value and number of keypoints had determined so that the detection n has the highest accuracy. The research was carried out on images without noise and with Gaussian noise.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 3; 561-569
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transverse energy propagation and interference of elliptical Gaussian beams
Autorzy:
Li, Jin
Tan, Shuang-Cheng
Powiązania:
https://bibliotekanauki.pl/articles/27310096.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
elliptical Gaussian beam
transverse energy flux
interference of EGBs
Opis:
Elliptical Gaussian beam (EGB) has many different physical properties from circular Gaussian beam. In this paper, the transverse energy flux and intensity of one and two coherent EGBs are studied. In our simulation, the transverse energy flux and intensity varying with waist ratio are discussed in detail. It has been found that through increasing the waist ratio, the transverse energy flux after interference would be strengthened significantly. Although the transverse energy flux is much weaker than the longitudinal energy flux, its signal to noise ratio has been verified to be strong enough for detection. Our derivations are still reasonable for another simulation with general experimental parameters. The simulation results are considered to be helpful for some physical experiments using the transverse energy flux of Gaussian beam, such as an important application in electromagnetic response produced by interaction of high-frequency gravitational waves.
Źródło:
Optica Applicata; 2023, 53, 2; 249--260
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Li-Ion battery state-of-health with Gaussian processes
Autorzy:
Dudek, Adrian
Baranowski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/28761940.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
lithium-ion batteries
state of health
Gaussian process
diagnostics
Opis:
The problem of lithium-ion cells, which degrade in time on their own and while used, causes a significant decrease in total capacity and an increase in inner resistance. So, it is important to have a way to predict and simulate the remaining usability of batteries. The process and description of cell degradation are very complex and depend on various variables. Classical methods are based, on the one hand, on fitting a somewhat arbitrary parametric function to laboratory data and, on the other hand, on electrochemical modelling of the physics of degradation. Alternative solutions are machine learning ones or non-parametric ones like support-vector machines or the Gaussian process (GP), which we used in this case. Besides using the GP, our approach is based on current knowledge of how to use non-parametric approaches for modeling the electrochemical state of batteries. It also uses two different ways of dealing with GP problems, like maximum likelihood type II (ML-II) methods and the Monte Carlo Markov Chain (MCMC) sampling.
Źródło:
Archives of Electrical Engineering; 2023, 72, 3; 643--659
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Adaptive Richardson-Lucy Algorithm for Medical Image Restoration
Autorzy:
Yaqoub, Qunoot A.
Al-Ani, Ayad A.
Powiązania:
https://bibliotekanauki.pl/articles/2200960.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
constraint least square filter
Gaussian blurring function
Gaussian noise function
inverse filter
non-blind deconvolution
point spread function
Richardson-Lucy algorithm
Wiener filter
Opis:
Image restoration is the process of estimating the original image content from a degraded picture. In this paper, the Richardson-Lucy iterative algorithm was developed to improve the quality of degraded medical images. It has been assumed that medical images are exposed to two types of degradation. The first type is the blur function in the Gaussian form with different widths, i.e. σ = 1 , 2, and 3. The second type of degradation was assumed to be of the independent white Gaussian noise type with different signal-to-noise ratio values: SNR = 10, 50 , and 100. The results obtained from the adaptive filter are compared, quantitatively, with different conventional filters: inverse, Wiener, and constraint least square, by applying different measures, such as: power signal to noise ratio (PSNR), structural similarity index (SSID), and root mean square error (RMSE). The comparison showed that the adaptive recovery filter achieves better results.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 1; 66--77
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the beam quality of a multi-Gaussian Schell-model vortex beam in atmospheric turbulence
Autorzy:
Suo, Qiangbo
Cui, Zhiwei
Han, Yiping
Powiązania:
https://bibliotekanauki.pl/articles/174273.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
multi-Gaussian Schell-model vortex beams
propagation factor
turbulent atmosphere
Opis:
Analytical formulas of the angular width and propagation factor of a multi-Gaussian Schell-model vortex (MGSMV) beam through atmospheric turbulence are derived on the basis of the extended Huygens–Fresnel integral and second-order moments of Wigner distribution function. Evolution properties of the angular width and propagation factor of MGSMV beams propagating in atmospheric turbulence are investigated numerically. The results show that a multi-Gaussian Schell-model beam is more affected by atmospheric turbulence than a MGSMV beam, which will be useful for the practical application of the MGSMV beam.
Źródło:
Optica Applicata; 2019, 49, 2; 191-202
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech emotion recognition under white noise
Autorzy:
Huang, C.
Chen, G.
Yu, H.
Bao, Y.
Zhao, L.
Powiązania:
https://bibliotekanauki.pl/articles/177301.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech emotion recognition
speech enhancement
emotion model
Gaussian mixture model
Opis:
Speaker‘s emotional states are recognized from speech signal with Additive white Gaussian noise (AWGN). The influence of white noise on a typical emotion recogniztion system is studied. The emotion classifier is implemented with Gaussian mixture model (GMM). A Chinese speech emotion database is used for training and testing, which includes nine emotion classes (e.g. happiness, sadness, anger, surprise, fear, anxiety, hesitation, confidence and neutral state). Two speech enhancement algorithms are introduced for improved emotion classification. In the experiments, the Gaussian mixture model is trained on the clean speech data, while tested under AWGN with various signal to noise ratios (SNRs). The emotion class model and the dimension space model are both adopted for the evaluation of the emotion recognition system. Regarding the emotion class model, the nine emotion classes are classified. Considering the dimension space model, the arousal dimension and the valence dimension are classified into positive regions or negative regions. The experimental results show that the speech enhancement algorithms constantly improve the performance of our emotion recognition system under various SNRs, and the positive emotions are more likely to be miss-classified as negative emotions under white noise environment.
Źródło:
Archives of Acoustics; 2013, 38, 4; 457-463
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated tracking and real time following of moving person for robotics applications
Autorzy:
Patoliya, Jignesh J.
Mewada, Hiren K.
Powiązania:
https://bibliotekanauki.pl/articles/384835.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
visual tracking
robot operating system
identity retention
Gaussian Mixture Model
Opis:
Presently the interaction of robots with human plays an important role in various social applications. Reliable tracking is an important aspect for the social robots where robots need to follow the moving person. This paper proposes the implementation of automated tracking and real time following algorithm for robotic automation. Occlusion and identity retention are the major challenges in the tracking process. Hence, a feature set based identity retention algorithm is used and integrated with robot operating system. The tracking algorithm is implemented using robot operating system in Linux and using OpenCV. The tracking algorithm achieved 85% accuracy and 72.30% precision. Further analysis of tracking algorithm corresponds to the integration of ROS and OpenCV is presented. The analysis of tracking algorithm concludes that ROS linking required 0.64% more time in comparison with simple OpenCV code based tracking algorithm.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2019, 13, 4; 31-37
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal Portfolio under Non-Extensive Statistical Mechanics and Value-at-Risk Constraints
Autorzy:
Zhao, Pan
Wang, Jixia
Song, Yu
Powiązania:
https://bibliotekanauki.pl/articles/1029999.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
Tsallis entropy
q-Gaussian distribution
value-at-risk
optimal portfolio
Opis:
In this study, we consider the optimal portfolio selection problem with a value-at-risk constraint in the non-extensive statistical mechanics framework. We propose a portfolio selection model, which is suitable not only for normal return distributions, but also for non-normal return distributions. Using Chinese stock data, under the normal and q-Gaussian return distributions, we provide empirical results. The results indicate that portfolio selections under the q-Gaussian return distributions are considerably different from those under the normal return distributions. Moreover, by using the q-Gaussian distribution, the underestimated portfolio risk can be effectively avoided.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1170-1173
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A generalized thermoelastic medium subjected to pulsed laser heating via a two-temperature model
Autorzy:
Abouelregal, Ahmed E.
Zenkour, Ashraf M.
Powiązania:
https://bibliotekanauki.pl/articles/949139.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
two-temperature model
thermoelasticity
non-Gaussian laser pulse
laser intensity
Opis:
This article investigates stress and induced temperature in an isotropic, homogeneous, thermoelastic half-space using a two-temperature generalized thermoelasticity model. The bounding plane surface of the present half-space continuum is subjected to a non-Gaussian laser pulse. Laplace’s transform space is considered to deduce a closed-form solution to the problem. In addition, the inversions of Laplace’s transformations have been carried numerically to obtain field quantities in the transient state. The effects of parameters of two-temperature, laser-pulse and laser intensity are investigated. A concluding remark for the graphical forms of the derived expressions is presented.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 631-639
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convergence of compound probability measures on topological spaces
Autorzy:
Kawabe, Jun
Powiązania:
https://bibliotekanauki.pl/articles/967153.pdf
Data publikacji:
1994
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Gaussian transition probabilities
continuous transition probabilities
compound probability measures
equicontinuity
Źródło:
Colloquium Mathematicum; 1994, 67, 2; 161-176
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A direct approach to linear-quadratic stochastic control
Autorzy:
Duncan, T. E.
Pasik-Duncan, B.
Powiązania:
https://bibliotekanauki.pl/articles/255863.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
linear-quadratic Gaussian control
Riccati equation for optimization
stochastic control
Opis:
A direct approach is used to solve some linear-quadratic stochastic control problems for Brownian motion and other noise processes. This direct method does not require solving Hamilton-Jacobi-Bellman partial differential equations or backward stochastic differential equations with a stochastic maximum principle or the use of a dynamic programming principle. The appropriate Riccati equation is obtained as part of the optimization problem. The noise processes can be fairly general including the family of fractional Brownian motions.
Źródło:
Opuscula Mathematica; 2017, 37, 6; 821-827
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of the Inverse Gaussian Process with hazard rate functions-based drifts applied to degradation modelling
Autorzy:
Rodríguez-Picón, Luis Alberto
Méndez-González, Luis Carlos
Pérez-Olguín, Iván JC
Hernández-Hernández, Jesús Israel
Powiązania:
https://bibliotekanauki.pl/articles/2175136.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
inverse Gaussian process
hazard rate function
degradation rate
variable drift
Opis:
The stochastic modelling of degradation processes requires different characteristics to be considered, such that it is possible to capture all the possible information about a phenomenon under study. An important characteristic is what is known as the drift in some stochastic processes; specifically, the drift allows to obtain information about the growth degradation rate of the characteristic of interest. In some phenomenon’s the growth rate cannot be considered as a constant parameter, which means that the rate may vary from trajectory to trajectory. Given this, it is important to study alternative strategies that allow to model this variation in the drift. In this paper, several hazard rate functions are integrated in the inverse Gaussian process to describe its drift in the aims of individually characterize degradation trajectories. The proposed modelling scheme is illustrated in two case studies, from which the best fitting model is selected via information criteria, a discussion of the flexibility of the proposed models is provided according to the obtained results.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 3; 590--602
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Controllable propagation of Pearcey–Gaussian beams in photorefractive media with fractional Schrödinger equation
Autorzy:
Guo, Teng
Gao, Ru
Ren, Shumin
Wang, Pengxiang
Xiao, Yan
Powiązania:
https://bibliotekanauki.pl/articles/2172852.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Pearcey-Gaussian beam
fractional Schrödinger equation
photorefractive medium
breathing soliton
Opis:
Taking the fractional Schrödinger equation as the theoretical model, the evolution behavior of the Pearcey–Gaussian beam in the photorefractive medium is studied. The results show that breathing solitons are generated when the nonlinear effect and the diffraction effect are balanced with each other. Nonlinear coefficients, Lévy index and beams amplitude affect breathing period of the soliton and maximum peak intensity. Within a certain range, the breathing period of the soliton decreases with the increase of the nonlinear coefficient and the Lévy index. However when the beams amplitude increases, the breathing period and the maximum peak intensity of the soliton increase. Under the photorefractive effect, due to the bidirectional self-acceleration property of the Pearcey beam, the solitons formed will propagate vertically. These properties can be used to manipulate the beam and have potential applications in optical switching, plasma channeling, particle manipulation, etc.
Źródło:
Optica Applicata; 2022, 52, 4; 627--638
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Supervisory optimal control using machine learning for building thermal comfort
Autorzy:
Abdufattokhov, Shokhjakhon
Mahamatov, Nurilla
Ibragimova, Kamila
Gulyamova, Dilfuza
Yuldashev, Dilyorjon
Powiązania:
https://bibliotekanauki.pl/articles/2204083.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
building thermal comfort
Gaussian processes
machine learning
model predictive control
Opis:
For the past few decades, control and building engineering communities have been focusing on thermal comfort as a key factor in designing sustainable building evaluation methods and tools. However, estimating the indoor air temperature of buildings is a complicated task due to the nonlinear and complex building dynamics characterised by the time-varying environment with disturbances. The primary focus of this paper is designing a predictive and probabilistic room temperature model of buildings using Gaussian processes (GPs) and incorporating it into model predictive control (MPC) to minimise energy consumption and provide thermal comfort satisfaction. The full probabilistic capabilities of GPs are exploited from two perspectives: the mean prediction is used for the room temperature model, while the uncertainty is involved in the MPC objective not to lose the desired performance and design a robust controller. We illustrated the potential of the proposed method in a numerical example with simulation results.
Źródło:
Operations Research and Decisions; 2022, 32, 4; 1--15
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation properties of partially coherent array beams with a non-uniform polarization
Autorzy:
Yang, Xianyang
Fu, Wenyu
Powiązania:
https://bibliotekanauki.pl/articles/27310095.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
partially coherent
radially polarisation
Gaussian Schell-model array beams
propagation properties
Opis:
We study a new class of partially coherent array beams with a non-uniform polarization, named radially polarized Gaussian Schell-model array (RPGSMA) beams and analyze the reliability conditions for the array beams based on the unified theory of coherence and polarization, Moreover, the statistical properties of such beam propagating in free space are investigated in detail. It is found that, the propagation properties of the RPGSMA beams are closely related to initial beam parameters. With an appropriate choice of the beam parameters, the average intensity will evolve into optical lattice patterns, and the degree of coherence (DOC) from the lattice distribution on the original plane evolves into a Gaussian profile in the far field, and the degree of polarization (DOP) appears a periodical grid-like distribution on propagation. These results may be beneficial to particle trapping and free-space optical communications.
Źródło:
Optica Applicata; 2023, 53, 2; 307--319
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
BADANIE PREFERENCJI PRZEDSIĘBIORSTW W STOSOWANIU ZAAWANSOWANYCH METOD ANALIZY DANYCH
SURVEY ANALYSIS ON ENTERPRENEURS’ PREFERENCES TOWARDS ADVANCED DATA ANALYSIS METHODS
Autorzy:
Barska, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/972826.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
analiza skupień
modele mieszanin rozkładów normalnych
cluster analysis
Gaussian mixture models
Opis:
Potrzeby firm w zakresie stosowania zaawansowanych metod przetwarzania danych są różne w zależności od branży funkcjonowania, możliwości finansowania, zachowań konkurencji, rozmiaru i zmienności gromadzonych informacji. W pewnych przypadkach technologie business intelligence, wizualizacja lub metody statystyczne stają się niezbędne do funkcjonowania firmy, w innych są sposobem zwiększenia wydajności oraz uzyskania przewagi konkurencyjnej. Celem publikacji jest analiza różnic w podejściu przedsiębiorstw do stosowania tych technologii. Sprawdzono, czy istnieją cechy powodujące, że dana grupa jest podatna na ofertę związaną z big data i data science. Realizacji tego celu służy analiza skupień, pozwalająca na wyznaczenie grup klientów o podobnej charakterystyce. Wyniki badania wskazują, że źródłem różnic są cechy demograficzne, odmienne oczekiwania oraz dotychczasowe doświadczenia.
Enterpreneurs’ needs in terms of advanced data analysis methods vary depending on the business sector, funding flexibility, competitors’ behavior, volume and volatility of stored information. Business intelligence, visualisation or statistical methods become essential for performing daily operations in some cases, while in the others they develop into a mean of increasing efficiency or gaining competitive advantage. This publication analyses the differences in enterprises' attitude towards application of hot technologies. An attempt is made to distinguish certain features that potentially make a particular group prone to use offered solutions. This objective is accomplished with a cluster analysis carried out to determine client segments sharing similar characteristics. The results indicate that main differences arise from demographic features, varied expectations and past experiences.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2018, 19, 2; 105-116
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
IMPRECISE RETURN RATES ON THE WARSAW STOCK EXCHANGE
Autorzy:
Piasecki, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/452883.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
Normal Inverse Gaussian distribution
uncertainty risk
imprecision risk
fuzzy present value
Opis:
The return rate in imprecision risk may be described as a fuzzy probabilistic set [Piasecki, 2011a]. On the other side, in [Piasecki, Tomasik 2013] is shown that the Normal Inverse Gaussiandistribution is the best matching probability distribution of logarithmic returns on Warsaw Stock Exchange. There will be presented the basic properties if imprecise return with the Normal Inverse Gaussian distribution of future value logarithm. The existence of distribution of expected return rate is discussed. All obtained results may be immediately applied for effectiveness analysis at risk of uncertainty and imprecision [Pi-asecki, 2011c]
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2014, 15, 1; 153-158
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the propagation of partially coherent cosh-Gaussian beams through an ABCD optical system in non-Kolmogorov turbulence by effective tensor approach
Autorzy:
Ma, Hongjie
Li, Jinsong
Chen, Yueyang
Powiązania:
https://bibliotekanauki.pl/articles/1835756.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
partially coherent
cosh-Gaussian beam
ABCD optical system
non-Kolmogorov turbulence
Opis:
An efficient tensor approach is used to study the propagation of partially coherent cosh-Gaussian beams through an ABCD optical system in non-Kolmogorov turbulence. Analytical expressions for the average intensity of the beam propagation are derived. The properties of the average intensity are investigated with a numerical example. One finds that the propagation of the beam with larger spatial coherence length is less affected by distance when the propagation distance is long enough, and as the Ch-parameter increases, the beam propagation is less effected by turbulent atmosphere. It is also found that the average intensity distribution of the cosh-Gaussian beams with larger spatial correlation length is more affected by the structure constant of turbulence (i.e., turbulence level). By choosing a suitable Ch-parameter and spatial coherence length, the partially coherent cosh-Gaussian beams can be better transmitted in non-Kolmogorov turbulence. Our results will be useful in free-space communication.
Źródło:
Optica Applicata; 2021, 51, 1; 147-158
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gaussian light beam propagation in inhomogeneous medium
Propagacja wiązki Gausowskiej w ośrodku niejednorodnym
Autorzy:
Pieszyński, K.
Powiązania:
https://bibliotekanauki.pl/articles/296458.pdf
Data publikacji:
2008
Wydawca:
Politechnika Łódzka. Wydawnictwo Politechniki Łódzkiej
Tematy:
wiązka gaussowska
propagacja
ośrodek niejednorodny
Gaussian light beam
propagation
inhomogeneous medium
Opis:
In this work the results of numerical calculations describing propagation of Gaussian light beam in inhomogeneous media is presented. Numerical calculation was based on scalar wave approximation. Additionally the split-step beam propagation method was exploited.
Praca przedstawia wyniki obliczeń numerycznych rozkładu natężenia wiązki lasera He-Ne w trakcie propagacji przez trzy niejednorodne ośrodki różniące się charakterem tejże niejednorodności. Do obliczeń wykorzystano przybliżenie pola skalarnego i rekurencyjnie liczono kolejne profile intensywności wiązki światła.
Źródło:
Scientific Bulletin. Physics / Technical University of Łódź; 2008, 29; 65-74
1505-1013
2449-982X
Pojawia się w:
Scientific Bulletin. Physics / Technical University of Łódź
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Moving Average control charts for Burr X and Inverse Gaussian distributions
Autorzy:
Shafqat, Ambreen
Aslam, Muhammad
Albassam, Mohammed
Powiązania:
https://bibliotekanauki.pl/articles/1181944.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
control chart
Burr X distribution
inverse Gaussian distribution
average run length
Opis:
The Burr X and inverse Gaussian (IG) distributions have been considered to design an attribute control chart for time truncated life test with the moving average (MA) scheme w. The presentation of the MA control chart has been estimated in terms of average run length (ARL) by using the Monte Carlo simulation. The ARL is determined for different values of sample sizes, MA statistics size, parameters’ values, and specified average run length. The performance of this new MA attribute control chart has been compared with the usual time truncated control chart for Burr X and IG distributions. The performance of a new control chart is better than that of the existing control chart.
Źródło:
Operations Research and Decisions; 2020, 30, 4; 81-94
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speaker Model Clustering to Construct Background Models for Speaker Verification
Autorzy:
Dişken, G.
Tüfekci, Z.
Çevik, U.
Powiązania:
https://bibliotekanauki.pl/articles/177299.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Gaussian mixture models
k-means
imposter models
speaker clustering
speaker verification
Opis:
Conventional speaker recognition systems use the Universal Background Model (UBM) as an imposter for all speakers. In this paper, speaker models are clustered to obtain better imposter model representations for speaker verification purpose. First, a UBM is trained, and speaker models are adapted from the UBM. Then, the k-means algorithm with the Euclidean distance measure is applied to the speaker models. The speakers are divided into two, three, four, and five clusters. The resulting cluster centers are used as background models of their respective speakers. Experiments showed that the proposed method consistently produced lower Equal Error Rates (EER) than the conventional UBM approach for 3, 10, and 30 seconds long test utterances, and also for channel mismatch conditions. The proposed method is also compared with the i-vector approach. The three-cluster model achieved the best performance with a 12.4% relative EER reduction in average, compared to the i-vector method. Statistical significance of the results are also given.
Źródło:
Archives of Acoustics; 2017, 42, 1; 127-135
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biometric speech signal processing in a system with digital signal processor
Autorzy:
Marciniak, T.
Weychan, R.
Stankiewicz, A.
Dąbrowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/200794.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biometry
speech processing
digital signal processor
Gaussian mixture models
vector quantization
Opis:
This paper presents an analysis of issues related to the fixed-point implementation of a speech signal applied to biometric purposes. For preparing the system for automatic speaker identification and for experimental tests we have used the Matlab computing environment and the development software for Texas Instruments digital signal processors, namely the Code Composer Studio (CCS). The tested speech signals have been processed with the TMS320C5515 processor. The paper examines limitations associated with operation of the realized embedded system, demonstrates advantages and disadvantages of the technique of automatic software conversion from Matlab to the CCS and shows the impact of the fixed-point representation on the speech identification effectiveness.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 3; 589-594
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One-match-ahead forecasting in two-team sports with stacked Bayesian regressions
Autorzy:
Lam, M. W. Y.
Powiązania:
https://bibliotekanauki.pl/articles/91870.pdf
Data publikacji:
2018
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
sports analytics
one-match-ahead forecasting
winning probability
Gaussian process regression
Opis:
There is a growing interest in applying machine learning algorithms to real-world examples by explicitly deriving models based on probabilistic reasoning. Sports analytics, being favoured mostly by the statistics community and less discussed in the machine learning community, becomes our focus in this paper. Specifically, we model two-team sports for the sake of one-match-ahead forecasting. We present a pioneering modeling approach based on stacked Bayesian regressions, in a way that winning probability can be calculated analytically. Benefiting from regression flexibility and high standard of performance, Sparse Spectrum Gaussian Process Regression (SSGPR) – an improved algorithm for the standard Gaussian Process Regression (GPR), was used to solve Bayesian regression tasks, resulting in a novel predictive model called TLGProb. For evaluation, TLGProb was applied to a popular sports event – National Basketball Association (NBA). Finally, 85.28% of the matches in NBA 2014/2015 regular season were correctly predicted by TLGProb, surpassing the existing predictive models for NBA.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2018, 8, 3; 159-172
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-Gaussian statistical measures of control performance
Autorzy:
Domański, P. D.
Powiązania:
https://bibliotekanauki.pl/articles/206277.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
Control Performance Assessment
statistical measures
PID
disturbance shadowing
non-Gaussian functions
Opis:
Statistical approach to Control Performance Assessment (CPA) is of great practical importance. This is particularly visible in process industry, where there are many PID loops. They are often assessed with measures derived from the Gaussian probabilistic density function. Standard deviation, variance, skewness or kurtosis form the majority of applied indexes. The review of data originating from process industry shows, however, to the contrary, that these signals have rather non-Gaussian properties and are mostly characterized by fat-tailed distribution disable the ability. Investigations show that strong disturbances may significantly disable the capacity of proper assessment. Standard measures often fail in such cases. It is shown that non-Gaussian measures can help with this problem. Various disturbances are tested and compared. Results show that fat-tailed distributions are an interesting alternative. They are less sensitive to disturbance shadowing and still make possible loop dynamic assessment.
Źródło:
Control and Cybernetics; 2017, 46, 3; 259-290
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Model of Three-Dimensional Ultrasonic Beam Interaction with an Immersed Plate
Autorzy:
Soucrati, H.
Chitnalah, A.
Aouzale, N.
Jakjoud, H.
Powiązania:
https://bibliotekanauki.pl/articles/177031.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic modeling
immersed plate
Gaussian beams decomposition
Green’s functions
NDUT
Opis:
This paper proposes an analytical model to describe the interaction of a bounded ultrasonic beam with an immersed plate. This model, based on the Gaussian beams decomposition, takes into account multiple reflections into the plate. It allows predicting three-dimensional spatial distributions of both transmitted and reflected fields. Thereby, it makes it easy to calculate the average pressure over the receiver’s area taking into account diffraction losses. So the acoustical parameters of the plate can be determined more accurately. A Green’s function for the interaction of an ultrasonic beam with the plate is derived. The obtained results are compared to those given by the angular spectrum approach. A good agreement is seen showing the validity of the proposed model.
Źródło:
Archives of Acoustics; 2018, 43, 4; 669-679
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Edge Detection Algorithms in Medical Image Processing
Autorzy:
Anas, Ruba
Elhadi, Hadeel A.
Ali, Elmustafa Sayed
Powiązania:
https://bibliotekanauki.pl/articles/1075754.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Canny
Edge detection
Gaussian Noise
LOG
Laplacian
Prewitt
Salt & Pepper Noise
Opis:
Imaging technology in Medicine let the doctors to see the interior portions of the body for easy diagnosis. It also helped doctors to make keyhole surgeries for reaching the interior parts without really opening too much of the body. Noise in medical images appears in an image from a variety sources or it is the random variation of brightness or color information in images. Edge detection is a common process in the treatment of medical images and it is a very useful task for object recognition of human organs. Edge detection also show where shadows fall in an image or any other distinct change in the intensity of an image due to noise effects. In this paper we evaluated the performance of different edge detection algorithms; Canny, Prewitt, LOG, and Laplacian with and without adding filer such as wiener and median. The statement of effectiveness in removing noise and preserving important information in medical image is identified by using quality measurements like PSNR and MSE. Results show that the best algorithm for displaying edge and removing salt & pepper noise is the Prewitt Algorithm after using the median filter. Additionally, it was found that the best algorithm for displaying edge and removing Gaussian noise is the Canny algorithm after using the median filter.
Źródło:
World Scientific News; 2019, 118; 129-143
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image Quality Assessment Using Edge Correlation
Autorzy:
Ruikar, J.
Sinha, A.
Chaudhury, S.
Powiązania:
https://bibliotekanauki.pl/articles/226152.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
image quality assessment
image quality metrics
steerable Gaussian filter
subjective assessment
Opis:
In literature, oriented filters are used for low-level vision tasks. In this paper, we propose use of steerable Gaussian filter in image quality assessment. Human visual system is more sensitive to multidirectional edges present in natural images. The most degradation in image quality is caused due to its edges. In this work, an edge based metric termed as steerable Gaussian filtering (SGF) quality index is proposed as objective measure for image quality assessment. The performance of the proposed technique is evaluated over multiple databases. The experimental result shows that proposed method is more reliable and outperform the conventional image quality assessment method.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 99-107
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectra of light absorption by phytoplankton pigments in the Baltic; conclusions to be drawn from a Gaussian analysis of empirical data
Autorzy:
Ficek, D.
Kaczmarek, S.
Ston-Egiert, J.
Wozniak, B.
Majchrowski, R.
Dera, J.
Powiązania:
https://bibliotekanauki.pl/articles/47835.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton pigment
remote sensing algorithm
Baltic Sea
Gaussian analysis
light absorption
Opis:
Analysed by differential spectroscopy, 1208 empirical spectra of light absorption apl(λ) by Baltic phytoplankton were spectrally decomposed into 26 elementary Gaussian component bands. At the same time the composition and concentrations of each of the 5 main groups of pigments (chlorophylls a, chlorophylls b, chlorophylls c, photosynthetic carotenoids and photoprotecting carotenoids) were analysed in 782 samples by HPLC. Inspection of the correlations between the intensities of the 26 elementary absorption bands and the concentrations of the pigment groups resulted in given elementary bands being attributed to particular pigment groups and the spectra of the mass-specific absorption coefficients established for these pigment groups. Moreover, balancing the absorption effects due to these 5 pigment groups against the overall absorption spectra of phytoplankton suggested the presence of a sixth group of pigments, as yet unidentified (UP), undetected by HPLC. Apr eliminary mathematical description of the spectral absorption properties of these UP was established. Like some forms of phycobilins, these pigments are strong absorbers in the 450–650 nm spectral region. The packaging effect of pigments in Baltic phytoplankton was analysed statistically, then correlated with the concentration of chlorophyll a in Baltic water. As a result, a Baltic version of the algorithm of light absorption by phytoplankton could be developed. This algorithm can be applied to estimate overall phytoplankton absorption spectra and their components due to the various groups of pigments from a knowledge of their concentrations in Baltic water.
Źródło:
Oceanologia; 2004, 46, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Focus shaping of Weierstrass solid immersion lens by an axisymmetric Bessel-modulated Gaussian beam
Autorzy:
Dong, X
Geng, T
Zhuang, S
Powiązania:
https://bibliotekanauki.pl/articles/174767.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Weierstrass solid immersion lens
Bessel-modulated Gaussian beam
vector diffraction theory
Opis:
Weierstrass solid immersion lens (SIL) has been used to obtain superresolution because a smaller focal size is desirable. In this paper, focus shaping of Weierstrass SIL illuminated by an axisymmetric Bessel-modulated Gaussian beam (QBG beam) is investigated. It has been found theoretically that the sharper focusing of Weierstrass SIL disappears for a certain beam order of QBG beam. For case of a smaller beam order, the focus still locates on the plane of Weierstrass SIL and Weierstrass SIL still plays a tighter focusing role. However, when the beam order increases continuously, the focus lefts the plane of Weierstrass SIL, and shifts along an optical axis considerably. In addition, under condition of the higher beam order, the dependence of the focal shift on the beam order is nearly linear, which may be used to alter a focal position conveniently.
Źródło:
Optica Applicata; 2013, 43, 2; s. 247-259
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł

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