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Wyszukujesz frazę "distribution function" wg kryterium: Temat


Tytuł:
Mosers Inequality for a class of integral operators
Autorzy:
Holland, Finbarr
Walsh, David
Powiązania:
https://bibliotekanauki.pl/articles/1289652.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Moser's Inequality
integral operator
distribution function
Opis:
Let 1 < p < ∞, q = p/(p-1) and for $f ∈ L^p(0,∞)$ define $F(x) = (1/x) ʃ_0^x f(t)dt$, x > 0. Moser's Inequality states that there is a constant $C_p$ such that $sup_{a≤1} sup_{f∈B_{p}} ʃ_{0}^{∞} exp[ax^{q}|F(x)|^{q} - x]dx= C_p$ where $B_p$ is the unit ball of $L^p$. Moreover, the value a = 1 is sharp. We observe that $F = K_1$ f where the integral operator $K_1$ has a simple kernel K. We consider the question of for what kernels K(t,x), 0 ≤ t, x < ∞, this result can be extended, and proceed to discuss this when K is non-negative and homogeneous of degree -1. A sufficient condition on K is found for the analogue of Moser's Inequality to hold. An internal constant ψ, the counterpart of the constant a, arises naturally. We give a condition on K that ψ be sharp. Some applications are discussed.
Źródło:
Studia Mathematica; 1995, 113, 2; 141-168
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The relationship between the parameters of wind speed
Autorzy:
Halchak, V.
Syrotyuk, S.
Syrotyuk, V.
Powiązania:
https://bibliotekanauki.pl/articles/411281.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
wind
wind speed
distribution function
mean values
Opis:
This paper analyzes the methods of mapping the velocity of wind flow, and using them to measure the performance of wind turbines. The dependencies of the two-parameter Weibull distribution function on the scale parameter are analyzed. It should be noted that the parameters of the distribution function, and therefore the repeatability are probabilistic. The characteristics of Rayleigh distribution for different values of the scale are presented. The analytical-expressions and peculiar velocities of the integer and half-integer values for the shape parameters reflect the relationship between the mean, mean square, average-cubic, and estimated wind-speeds. It is shown that the ratio of the square of the average speed to the standard, regardless of the values of the shape-parameters and the scale-ratio can be replaced by the corresponding G-functions.The theoretical-calculation to design the medium-speed and its relation to the current and average speeds for the Weibull distribution with a half-integer values and the shape-parameter is presented. It is proved that the recommendation considers the speed of the medium design to be proportional to the mean, and permissible only if the distribution is close to normal. It has been established that the ratio between average wind velocities (in the case of Weilbull distribution parameter) are determined only by its form and the average velocity through the scale parameter. Weibull distribution allows to facilitate and simplify their calculation methodology so as to assess the energy parameters of wind turbines.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2015, 4, 4; 95-100
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Modification of the Probability Weighted Method of Moments and its Application to Estimate the Financial Return Distribution Tail
Autorzy:
Małecka, Marta
Pekasiewicz, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/465796.pdf
Data publikacji:
2014
Wydawca:
Główny Urząd Statystyczny
Tematy:
PWMM
generalized Pareto distribution
tail estimate
distribution function estimate
Opis:
The issue of fitting the tail of the random variable with an unknown distribution plays a pivotal role in finance statistics since it paves the ground for estimation of high quantiles and subsequently offers risk measures. The parametric estimation of fat tails is based on the convergence to the generalized Pareto distribution (GPD). The paper explored the probability weighted method of moments (PWMM) applied to estimation of the GPD parameters. The focus of the study was on the tail index, commonly used to characterize the degree of tail fatness. The PWMM algorithm requires specification of the cdf estimate of the so-called excess variable and depends on the choice of the order of the probability weighted moments. We suggested modification of the PWMM method through the application of the level crossing empirical distribution function. Through the simulation study, the paper investigated statistical properties of the GPD shape parameter estimates with reference to the PWMM algorithm specification. The simulation experiment was designed with the use of fat-tailed distributions with parameters assessed on the basis of the empirical daily data for DJIA index. The results showed that, in comparison to the commonly used cdf formula, the choice of the level crossing empirical distribution function improved the statistical properties of the PWMM estimates. As a complementary analysis, the PWMM tail estimate of DJIA log returns distribution was presented.
Źródło:
Statistics in Transition new series; 2014, 15, 3; 495-506
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of molding conditions on the quality of geopolymer surfaces
Autorzy:
Jaglarz, Janusz
Wyszyński, Dominik
Lach, Michał
Mikuła, Janusz
Duraj, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/173702.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surface topography
bidirectional reflectance distribution function
ellipsometry
spectrophotometry
Opis:
The presented work describes the method of measuring surface topography with application of BRDF (bidirectional reflectance distribution function), ellipsometry and spectrophotometry. This non-contact method enables measurement and analysis of large area surfaces, such as plasters and facades. A standard method of topography analysis does not describe sufficiently all of the interesting features. The visual aspect of the surface evaluation is very important from the functional and utilitarian point of view. The proposed methods of surface analysis enable not only the quantitative evaluation but also indirectly the qualitative properties (visual aspects).
Źródło:
Optica Applicata; 2020, 50, 1; 135-146
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical sizing of cement particles
Autorzy:
Gorsky, M. P.
Maksimyak, P. P.
Powiązania:
https://bibliotekanauki.pl/articles/174679.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
transverse coherence
polarization interferometer
cement
size distribution function
Opis:
We represent the optical correlation technique of cement particle sizing based on the transverse coherency function measurement using a polarization transverse shearing interferometer. It is shown that a set of particles with random shapes and orientations produces a coherence function, which is the same as a function of the set of spherical particles. The proposed technique of experimental data processing decreases the dependence of the result on interferometer noise, emission source intensity fluctuations and differences in the refraction index of isolated cement particles. The described technique allows fast and high reliable determining of the size distribution function parameters for a set of cement particles.
Źródło:
Optica Applicata; 2017, 47, 4; 511-519
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Testing Linearity of Trend Function
O testowaniu hipotezy o liniowości trendu
Autorzy:
Kończak, Grzegorz
Wywiał, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/905044.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
kernel estimator
trend
testing
approximation of distribution function
Opis:
Testing the goodness of fit between a hypothetical trend function and its non-parametric variant will be considered. This problem was analysed e.g. by Domanski (1979, 1990), Wywiał (1990, 1995). Our result can be treated as a modification of the test proposed by Azzalini and Bowman (1993). The hypothetical trend function will be denoted by f(t, θ). It is estimated by an unbiased method. A trend function can be estimated by means of an non-parametric method. Azzalini and Bowman suggested testing the hypothesis on the linearity of the trend on the basis of the ratio of two residual variances. One of them is the residual variance of the trend estimated by means of the least square method and the other one by means of a non-parametric method. The well known Pearson curves are used for an approximation of the distribution function of the ratio. We use a different method in order to approximate the distribution of the test statistic. The table with quantiles of the test statistic are evaluated.
W artykule rozważano pewną modyfikację testu dla hipotezy głoszącej, że trend szeregu czasowego ma postać liniową, który zaproponowali Azzalini i Bowman (1903). Statystyka testowa jest ilorazem wariancji resztowej estymatora wartości funkcji liniowej trendu uzyskanej metodą najmniejszych kwadratów i pewnej formy kwadratowej reszt oceny trendu otrzymanego metodą estymacji jądrowej. Wysokie wartości tego ilorazu świadczą przeciwko hipotezie o liniowości funkcji trendu. Ze względu na złożoną postać proponowanej statystyki Azzalini i Bowman wykorzystali do aproksymacji jej rozkładu prawdopodobieństwa tzw. krzywe Pearsona W niniejszym artykule stosuje się do przybliżenia rozkładu sprawdzianu testu inną metodę wykorzystującą technikę całkowania numerycznego. Przy założeniu liniowej postaci funkcji trendu pozwoliło to wyznaczyć numerycznie kwantyle rzędu 0,9, 0,95 i 0,99 rozważanej statystyki testowej. Przedstawione wartości kwantyli mogą stanowić podstawę do podjęcia decyzji o ewentualnym odrzuceniu hipotezy o postaci trendu liniowego.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2009, 225
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Global approximations for the γ-order Lognormal distribution
Autorzy:
Toulias, Thomas
Powiązania:
https://bibliotekanauki.pl/articles/729844.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
cumulative distribution function
γ-order Lognormal distribution
global Padé approximation
Opis:
A generalized form of the usual Lognormal distribution, denoted with $_γ$, is introduced through the γ-order Normal distribution $_γ$, with its p.d.f. defined into (0,+∞). The study of the c.d.f. of $_γ$ is focused on a heuristic method that provides global approximations with two anchor points, at zero and at infinity. Also evaluations are provided while certain bounds are obtained.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2013, 33, 1-2; 99-110
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Probability Distribution Function for Modelling Path Loss for Wireless Channels Applications over Micro-Cellular Environments of Ondo State, Southwestern Nigeria
Autorzy:
Abiodun, Chukwutem Isaac
Ojo, Joseph Sunday
Powiązania:
https://bibliotekanauki.pl/articles/1075736.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Path loss
normal distribution
probability distribution function
wet and dry season
Opis:
In this research, the most appropriate probability distribution function for modelling RF signal path loss values in both wet and dry season months over urban, suburban and rural environments of Ondo State are presented. The data used consist of a drive test measurement campaign carried out in a typical urban, suburban and rural areas of Ondo State, South-western Nigeria in both wet and dry season months. The received signal strength (RSS) values were collected and recorded in log files alongside other environmental parameters using TEMS investigation tools. Path loss values were deduced from the measured RSS values. Some selected probability distribution function namely: gamma, lognormal, extreme value, logistic, Weibull and normal distributions function were fitted to the measured path loss values and the best suited one determined using three different metric measures. Results obtained show that normal distribution presents the best probability distribution curve for modelling the RF signal path loss over different micro-cellular environments of Ondo State. A typical result of the rural environment indicates that in wet season months, the normal distribution has RMSE of 7.060 dB, Relative Error of 12.480 % and R2 of 0.988, in dry season months, the RMSE is 9.060 dB, Relative Error of 13.450 % and R2 of 0.985. When compared with other distribution models, the same trend could be seen in other environments, although with different values of RMSE, Relative error and R2. The mean and the standard deviation parameters for the normal distribution estimated, vary seasonal-wise and are environment dependent. However, the rural environment exhibited a wider seasonal variations when compared with the other environments. The results of this research is useful as a first-hand information in the planning of future wireless propagation channels in the studied environments.
Źródło:
World Scientific News; 2019, 118; 74-88
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability analysis of the model describing the fractional composition of coal
Analiz ustojjchivosti modeli opisanija frakcionnogo sostava ugla
Autorzy:
Grachyov, O.
Powiązania:
https://bibliotekanauki.pl/articles/793116.pdf
Data publikacji:
2013
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
fractional composition
coal
distribution function
stability analysis
numerical experiment
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2013, 13, 3
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kernel Estimation of Cumulative Distribution Function of a Random Variable with Bounded Support
Autorzy:
Baszczyńska, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/465685.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Statystyczny
Tematy:
boundary effects
cumulative distribution function
kernel method
bounded support
Opis:
In the paper methods of reducing the so-called boundary effects, which appear in the estimation of certain functional characteristics of a random variable with bounded support, are discussed. The methods of the cumulative distribution function estimation, in particular the kernel method, as well as the phenomenon of increased bias estimation in boundary region are presented. Using simulation methods, the properties of the modified kernel estimator of the distribution function are investigated and an attempt to compare the classical and the modified estimators is made.
Źródło:
Statistics in Transition new series; 2016, 17, 3; 541-556
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of spectral spatial di stribution of scattering materials for rear projection screens used in virtual reality systems
Autorzy:
Mazikowski, A.
Trojanowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/220880.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
scattering distribution function
BSDF
virtual reality
CAVE
spectroscopy
luminance
Opis:
Rapid development of computing and visualisation systems has resulted in an unprecedented capability to display, in real time, realistic computer-generated worlds. Advanced techniques, including three-dimensional (3D) projection, supplemented by multi-channel surround sound, create immersive environments whose applications range from entertainment to military to scientific. One of the most advanced virtual reality systems are CAVE-type systems, in which the user is surrounded by projection screens. Knowledge of the screen material scattering properties, which depend on projection geometry and wavelength, is mandatory for proper design of these systems. In this paper this problem is addressed by introducing a scattering distribution function, creating a dedicated measurement setup and investigating the properties of selected materials used for rear projection screens. Based on the obtained results it can be concluded that the choice of the screen material has substantial impact on the performance of the system.
Źródło:
Metrology and Measurement Systems; 2013, 20, 3; 443-452
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating normal density and normal distribution function: is Kolmogorovs estimator admissible?
Autorzy:
Rukhin, Andrew
Powiązania:
https://bibliotekanauki.pl/articles/1340688.pdf
Data publikacji:
1993
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
point estimation
normal density
Bayes estimator
quadratic loss
admissibility
normal distribution function
Opis:
The statistical estimation problem of the normal distribution function and of the density at a point is considered. The traditional unbiased estimators are shown to have Bayes nature and admissibility of related generalized Bayes procedures is proved. Also inadmissibility of the unbiased density estimator is demonstrated.
Źródło:
Applicationes Mathematicae; 1993-1995, 22, 1; 103-115
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical identification of Preisach distribution function including temperature effects
Autorzy:
Chelghoum, Leila
Powiązania:
https://bibliotekanauki.pl/articles/2086685.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic hysteresis
Preisach distribution function
Preisach model
soft ferromagnetic materials
temperature effect
Opis:
Magnetic hysteresis occurs in most electrical engineering devices once soft ferromagnetic materials are exposed to relatively high temperatures. According to several scientific studies, magnetic properties are strongly influenced by temperature. The development of models that can accurately describe the thermal effect on ferromagnetic materials is still an issue that inspires researchers. In this paper, the effect of temperature on magnetic hysteresis for ferromagnetic materials is investigated using a self-developed numerical method based on the Preisach distribution function identification. It employs a parameter depending on both temperature and the Curie temperature. This approach is of the macroscopic phenomenological type, where the variation of the magnetization (in direct connection with the Preisach triangle) is related to the observed macroscopic hysteretic behavior. The isotropic character of the material medium is predominant. The technique relies on a few experimental data extracted from the first magnetization curve provided by metallurgists. The ultimate goal is to provide a simple and robust magnetic behavior modeling tool for designers of electrical devices. Temperature is introduced at the stage of identifying the distribution function of the Preisach model. This method is validated by the agreement between the experimental data and the simulation results. The developed method is very accurate and efficient in modeling the hysteresis of ferromagnetic materials in engineering particularly for systems with ferromagnetic components and electromagnetic-thermal coupling.
Źródło:
Archives of Electrical Engineering; 2022, 71, 2; 297--309
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Infinite-Valued Łukasiewicz Logic and Probability
Autorzy:
Czelakowski, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/749934.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
probability
cumulative distribution function
the infinite-valued standard Łukasiewicz algebra
consequence relation
Opis:
The paper concerns the algebraic structure of the set of cumulative distribution functions as well as the relationship between the resulting algebra and the infinite-valued Łukasiewicz algebra. The paper also discusses interrelations holding between the logical systems determined by the above algebras.
Źródło:
Bulletin of the Section of Logic; 2017, 46, 1/2
0138-0680
2449-836X
Pojawia się w:
Bulletin of the Section of Logic
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of laser radar cross-section of a spatial object and its experimental verification
Autorzy:
Cao, Y.-H.
Wang, Z.
Bai, L.
Wu, Z.
Li, H.-Y.
Li, Y.-H.
Powiązania:
https://bibliotekanauki.pl/articles/174167.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bidirectional reflectance distribution function
BRDF
laser radar cross-section
LRCS
spatial object
Opis:
Bidirectional reflectance distribution function of some artificial satellite used materials at the wavelength of 1.06 μm was measured in laboratory. Bidirectional reflectance distribution function (BRDF) models of these materials were established with the five-parameter BRDF model. Laser radar cross-section of a scaled satellite with various materials was calculated, and characteristics of laser radar cross-section of the satellite were discussed. Measurement system to measure laser radar cross-section of the satellite was established and the scaled satellite model was measured. By analyzing the measured data and calculated data, it can be clearly seen that the BRDF of the surface materials and the laser incidence angle are two of main influential factors of the scaled satellite’s laser radar cross-section. These works can provide a reference for design of the lidar system.
Źródło:
Optica Applicata; 2017, 47, 4; 521-532
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł

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