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Tytuł:
Losowe właściwości błędu kwantowania w systemie pomiarowym
Random properties of quantization error in measuring system
Autorzy:
Jakubiec, J.
Powiązania:
https://bibliotekanauki.pl/articles/156424.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
kwantowanie
rozkład błędu kwantowania
quantization
quantization error distribution
Opis:
Obliczanie niepewności wyników realizacji algorytmów przetwarzania w systemie pomiarowym wymaga losowego opisu błędu kwantowania. Podstawą uzyskiwania tego rodzaju opisu jest analiza właściwości układu realizującego kwantowanie. W pracy przedstawiono wstępne wyniki badań symulacyjnych wybranych rozwiązań kwantyzatorów przeprowadzonych przy użyciu metody Monte Carlo, co pozwala na uzyskanie histogramów charakteryzujących w pełni losowe właściwości błędu kwantowania.
Digital processing in measuring systems requires, shown in Fig. 1, digitalization of varying in time continuous signals. Quantization of samples is a measuring process, so it should be described in metrological categories. Complete information about inaccuracy of quantization can be given by probabilistic description of error sources arousing during this operation []. The paper deals with analysis of random properties of quantization errors on example of chosen realizations of quantizers. The analysis has been made by using Monte Carlo method, which permits to obtain, in a relatively simple way, large sets of data that can be presented as histograms. The investigated types of quantizers are shown in Figs. 2, 6 and 8, while the exemplary histograms in Figs. 4, 5, 7 and 9. The histograms can be divided into two categories. The first one describes properties of quantization errors in the situation when the quantized quantity changes randomly in its measuring range. The quantization error in this case has the rectangular or triangle distribution. The second kind of histograms shows properties of errors when the quantized quantity is constant in time. In this case the histograms contains one or two values only so the properties of the errors should be seen as deterministic. Moreover, the shape of histogram depends on the value of the quantized quantity. One may try to average a series of quantization results but the obtained the results vary dependently on the measure value, number of the series elements an kind of the quantize. The general conclusion is that in the second case there is necessary to continue investigations directed to the problems of averaging data obtained from ADC converters.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 1, 1; 8-11
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the strategy combining monetary unit sampling and a Horvitz-Thompson estimator of error amount in auditing – results of a simulation study
Autorzy:
Janusz, Bartłomiej
Powiązania:
https://bibliotekanauki.pl/articles/1194460.pdf
Data publikacji:
2019-07-02
Wydawca:
Główny Urząd Statystyczny
Tematy:
audit sampling
Monetary Unit Sampling
Horvitz-Thompson estimator
error distribution
Opis:
Auditors need information on the performance of different statistical methods when applied to audit populations. The aim of the study was to examine the reliability and efficiency of a strategy combining systematic Monetary Unit Sampling and confidence intervals for the total error based on the Horvitz-Thompson estimator with normality assumption. This strategy is a possible alternative for testing audit populations with high error rates. Using real and simulated data sets, for the majority of populations, the interval coverage rate was lower than the assumed confidence level. In most cases confidence intervals were too wide to be of practical use to auditors. Confidence intervals tended to become wider as the observed error rate increased. Tests disclosed the distribution of the HorvitzThompson estimator was not normal. A detailed analysis of the distributions of the error amount in the examined real audit populations is also given.
Źródło:
Statistics in Transition new series; 2019, 20, 2; 85-106
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On non-existence of moment estimators of the GED power parameter
Autorzy:
Stawiarski, Bartosz
Powiązania:
https://bibliotekanauki.pl/articles/729730.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Generalized Error Distribution
nonparametric bootstrap
bootstrap consistency
moment estimator
power parameter
Opis:
We reconsider the problem of the power (also called shape) parameter estimation within symmetric, zero-mean, unit-variance one-parameter Generalized Error Distribution family. Focusing on moment estimators for the parameter in question, through extensive Monte Carlo simulations we analyze the probability of non-existence of moment estimators for small and moderate samples, depending on the shape parameter value and the sample size. We consider a nonparametric bootstrap approach and prove its consistency. However, despite its established asymptotics, bootstrap does not substantially improve the statistical inference based on moment estimators once they fall into the non-existence area in case of small and moderate sample sizes.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2016, 36, 1-2; 5-23
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wnioskowanie o rzędzie kointegracji dla modelu VEC ze składnikiem losowym z rozkładu Su Johnsona
Inference on cointegration rank for a VEC model with the Su Johnson error distribution
Autorzy:
Kębłowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/422718.pdf
Data publikacji:
2013
Wydawca:
Główny Urząd Statystyczny
Tematy:
rozkład reszt o grubych ogonach
rozkład Johnsona
wnioskowanie małopróbkowe
rząd kointegracji
fat-tailed error distribution
Johnson distribution
small sample inference
cointegration rank
Opis:
Artykuł przedstawia wyniki analiz Monte Carlo własności małopróbkowych testów rzędu kointegracji dla modelu VEC ze składnikiem losowym pochodzącym z rozkładu skośnego, leptokurtycznego. Analiza przeprowadzana jest dla testu asymptotycznego, testów z poprawkami na liczbę stopni swobody, testu z poprawką Bartletta, testu bootstrapowego oraz testu bootstrapowego z poprawką Bartletta w roli surogatu podwójnego testu bootstrapowego. Wyniki eksperymentów wskazują, że testy liczby relacji kointegrujących oparte na regule ilorazu wiarygodności są odporne ze względu na rozmiar jak i moc testu, gdy składnik losowy pochodzi z rozkładu skośnego, leptokurtycznego, aproksymowanego rozkładem Su Johnsona, zamiast z wielowymiarowego rozkładu normalnego.
Performance of small-sample cointegration rank tests is investigated within the framework of a VEC model with skewed fat-tailed error distribution. The Monte Carlo analysis is conducted for: asymptotic test, tests with degrees-of-freedom corrections, test with Bartlett correction, bootstrap test, and bootstrap test with Bartlett correction, as a surrogate of double bootstrap test. The results indicate that the small-sample cointegration rank tests are robust to skewed fat-tailed error distribution, approximated by Su Johnson distribution, with respect to size and power of these tests.
Źródło:
Przegląd Statystyczny; 2013, 60, 2; 235-249
0033-2372
Pojawia się w:
Przegląd Statystyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
VaR in risk analysis on DAM and models of volatility of variance
VaR w analizie ryzyka na RDN a modele zmienności wariancji
Autorzy:
Ganczarek, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/907049.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
Generalized Autoregressive Conditional Heteroscedasticity (GARCH)
Generalized Error Distribution (GED)
nonnal distribution
t-Student’s distribution
Value-at-Risk (VAR)
Conditional Value-at-Risk (CVaR)
failure test
Opis:
The aim of this paper is to describe and measure risk on the Day Ahead Marked (DAM) of the Polish Power Exchange. In this paper downside risk measures such as Vcilue-at-Risk (VaR) and Conditional Value-at-Risk (CVaR) are presented. These measures were estimated on the basis of the Generalized Autoregressive Conditional Heteroscedasticity (GARCH). They are applied to time series of the logarithmic rate of return of prices from the DAM from March to October 2003. The Kupiec test was used to choose an appropriate heteroscedasticity model to compute VaR and CVaR and to describe and measure risk on the DAM.
W pracy przeprowadzono analizę ryzyka na Rynku Dnia Następnego (RDN) Towarowej Giełdy Energii. Do pomiaru ryzyka zmiany ceny na RDN wykorzystano wartości zagrożone: Value-at-Risk (VaR) oraz Conditional Value-at-Risk (CVaR), oszacowane na podstawie modeli z warunkową wariancją: Generalized Autoregressive Conditional Heteroscedasticity (GARCH). Do oceny efektywności oszacowanych wartości VaR oraz CVaR wykorzystano test przekroczeń Kupca. Analizę ryzyka przeprowadzono na szeregach czasowych dziennych logarytmicznych stóp zwrotu cen energii elektrycznej notowanej na RDN w okresie od marca do października 2003.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2008, 216
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possible testing of geodetic equipment using the methods of mathematical statistics
Możliwość badania sprzętu geodezyjnego metodami statystyki matematycznej
Autorzy:
Czempas, Tomasz
Dwulit, Petro
Krupiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/100478.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie
Tematy:
statistical compatibility test
statistical identity test
geodetic measurements
error distribution
testing of measurement correctness
statistical hypothesis
test zgodności statystycznej
test tożsamości statystycznej
pomiary geodezyjne
rozkład błędów
testowanie poprawności pomiaru
hipoteza statystyczna
Opis:
The work presents selected methods of mathematical statistics applied to the examination of the correctness of geodetic equipment operation. Specifically, measurements made with electronic total stations will be tested using statistical compatibility tests and identity tests of empirical measurement error distributions with the theoretical normal distribution N (0;1).
Praca prezentuje pewne sposoby statystyki matematycznej w zastosowaniu do badania poprawności działania sprzętu geodezyjnego. Konkretnie za pomocą statystycznych testów zgodności oraz testów identyczności rozkładów błędów pomiarów empirycznych z teoretycznym rozkładem normalnym N(0;1), zostaną przebadane pomiary wykonane tachimetrami elektronicznymi.
Źródło:
Geomatics, Landmanagement and Landscape; 2019, 2; 9-19
2300-1496
Pojawia się w:
Geomatics, Landmanagement and Landscape
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cumulative Sum Control Charts for Truncated Normal Distribution under Measurement Error
Autorzy:
Sankle, R.
Singh, J. R.
Mangal, I. K.
Powiązania:
https://bibliotekanauki.pl/articles/465820.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Tematy:
Truncated Normal Distribution Measurement Error
ARL and CSCC
Opis:
In the present paper Cumulative Sum Control Chart (CSCC) for the truncated normal distribution under measurement error (r) is discussed. The sensitivity of the parameters of the V-Mask and the Average Run Length (ARL) is studied through numerical evaluation for different values of r.
Źródło:
Statistics in Transition new series; 2012, 13, 1; 95-106
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmniejszenie błędu metody związanego ze zniekształconym rozkładem prędkości w dwudrogowym przepływomierzu ultradźwiękowym
The reducing of the method error connected with distorted velocity distribution in two-path ultrasinic flowmeter
Autorzy:
Waluś, S.
Powiązania:
https://bibliotekanauki.pl/articles/152741.pdf
Data publikacji:
1999
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Opis:
Przedstawiono koncepcję dwudrogowego pzepływomierza ultradźwiękowego z drogami skrzyżowanymi. Podano zasady tworzenia modeli matematycznych zniekształconych rozkładów prędkości i przedstawiono cztery modele. Dla tych modeli wyprowadzono wzory na współczynnik kształtu rozkładu prędkości oraz na błąd metody. W przypadku zniekształconego nieosiowosymetrycznego rozkładu prędkości uzyskuje się znaczne zmniejszenie błędu metody dla przepływomierza dwudrogowego w porównaniu z jednodrogowym.
The conception of two-path primary device of an ultrasonic flowmeter with crossed pates is introduced. The rules of modelling of distorted velocity distributions are introduced and there are given four mathematical models. The distorted velocity distribution consist of two elements: an axisymmetrical elementof a velocity distribution and distorted one. The simplified diagram of the primary device of an ultrasonic flowmeter is introduced and the velocity distribution shape coefficient is defined and calculated for these four models. The method errors for the one-path and two-path primary device of an ultrasonic flowmeter are calculated and compared. For nonaxisymmetrical distorted velocity distribution two-path primary device with crossed pates gives radical error reducing.
Źródło:
Pomiary Automatyka Kontrola; 1999, R. 45, nr 12, 12; 34-38
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach to dtm error estimation basing on laplacian probability distribution function
Autorzy:
Hejmanowska, B.
Kay, S.
Powiązania:
https://bibliotekanauki.pl/articles/130024.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
Aerial
lidar
accuracy
point cloud
laser scanning
LIDAR
dokładność
chmura punktów
skanowanie laserowe
Opis:
A Digital Terrain Model (DTM) derived from Airborne Laser Scanning (ALS) was the subject of our research. In this paper, the vertical accuracy of the DTM was analyzed on the basis of the commonly used statistics, i.e. mean error and standard deviation, assuming a normal (Gauss) error distribution. The further approach, the so-called robust method (Höhle, Höhle 2009), was also tested, where the median was a substitute for the mean error and the Normalized Median Absolute Deviation (NMAD) for the standard deviation. An alternative method based on the Laplace function is proposed in the paper for describing the probability density function, where the parameters of the Laplace function are proposed for DTM error estimation. The test area was near the Joint Research Centre in Ispra, Italy; raw ALS data covering the test area were collected in 2005 and processed for DTM generation. Accuracy analysis was performed based on the comparison of DTM with the raw ALS data and with in-situ height measurements. The distribution of DTM errors calculated from ALS data was significantly non-normal, confirming other results reported in the literature. The Gauss distribution function considerably overestimated the vertical DTM errors; however, the robust method underestimated them. The Laplace function matched the error histograms the best, and accuracy parameters derived from this function could be considered as an alternative method for DTM accuracy evaluation.
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2011, 22; 201-213
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Error statistics for concatenated systems on non-renewal time-varying channels
Autorzy:
Pimentel, C.
Powiązania:
https://bibliotekanauki.pl/articles/309548.pdf
Data publikacji:
2001
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
finite state channels
multigap distribution
constrained codes
concatenated systems
Gilbert-Elliott channels
combinatorial methods
Opis:
The statistics of the error process generated by a discrete super channel formed by the concatenation of a constrained encoder, a non-renewal finite state channel (FSC), and a constrained decoder is studied in this paper. First, recursions are developed for the error weight distribution. This statistics is relevant to the design of coding schemes and interleaving in concatenated. systems. We also study the renewal nature of the residual error process as modified by the constrained decoder. Ferreira et al. conjectured that if the channel model is a renewal FSC, the super channel can be modeled as a similar renewal model. We use a statistics called the multigap distribution to analytically disprove this hypothesis. Furthermore, the effect of interleaving is investigated from a new perspective using the variance of the multigap distribution.
Źródło:
Journal of Telecommunications and Information Technology; 2001, 3; 55-60
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traceability of gas flow measurements in complex distribution systems - uncertainty approach vs error approach
Autorzy:
Džemić, Zijad
Širok, Brane
Drnovšek, Janko
Powiązania:
https://bibliotekanauki.pl/articles/220509.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
calibration
energy efficiency
error analyses
measurement uncertainty
traceability
Opis:
The objective of the paper is to analyse traceability issues in real-life gas flow measurements in complex distribution systems. The initial aim is to provide complete and traceable measurement results and calibration certificates of gas-flow meters, which correspond to specific installation conditions. Extensive work has been done to enable a more credible decision on how to deal in particular situations with the measurement uncertainty which is always subject of a flow meter’s calibration as a quantitative parameter value obtained in laboratory, and with the qualitative statement about the error of an outdoor meter. The laboratory simulation of a complex, real-life distributed system has been designed to achieve the initial aim. As an extension of standardized procedures that refer to the laboratory conditions, the proposed methods introduce additional “installation-specific” error sources. These sources could be either corrected (if identified) or considered as an additional “installation-specific” uncertainty contribution otherwise. The analysis and the results of the experimental work will contribute to more precise and accurate measurement results, thus assuring proper measurements with a known/estimated uncertainty for a specific gas flow installation. Also, the analysis will improve the existing normative documents by here presented findings, as well as fair trade in one of the most important and growing energy consumption areas regarding the legal metrology aspects. These facts will enable comparing the entire quantity of gas at the input of a complex distributed system with the cumulative sum of all individual gas meters in a specific installation.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 419-429
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interval shrinkage estimation of the parameter of exponential distribution in the presence of outliers under loss functions
Autorzy:
Nasiri, Parviz
Powiązania:
https://bibliotekanauki.pl/articles/2108120.pdf
Data publikacji:
2022-09-14
Wydawca:
Główny Urząd Statystyczny
Tematy:
interval information
mean square error
shrinkage estimator
exponential distribution
uniform distribution
outliers
Linex loss function
Opis:
In this paper, we studied estimators based on an interval shrinkage with equal weights point shrinkage estimators for all individual target points θ¯ ∈ (θ0, θ1) for exponentially distributed observations in the presence of outliers drawn from a uniform distribution. Estimators obtained from both shrinkage and interval shrinkage were compared, showing that the estimators obtained via the interval shrinkage method perform better. Symmetric and asymmetric loss functions were also used to calculate the estimators. Finally, a numerical study and illustrative examples were provided to describe the results.
Źródło:
Statistics in Transition new series; 2022, 23, 3; 65-78
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sum of gamma and normal distribution
Autorzy:
Sitek, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/1931403.pdf
Data publikacji:
2020
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
mixture of probability distribution
statistical auditing
sum of gamma and normal distribution
accounting error
mieszanka rozkładu prawdopodobieństwa
audyt statystyczny
suma rozkładu gamma i normalnego
błąd księgowy
Opis:
Purpose: The article shows how to model audit errors using mixtures of probability distribution. Design/methodology/approach: In financial accounting, data about the economic activities of a given firm is collected and then summarized and reported in the form of financial statements. Auditing, on the other hand, is the independent verification of the fairness of these financial statements. An item in an audit sample produces two pieces of information: the book (recorded) amount and the audited (correct) amount. The difference between the two is called the error amount. The book amounts are treated as values of a random variable whose distribution is a mixture of the distributions of the correct amount and the true amount contaminated by error. The mixing coefficient is equal to the proportion of the items with non-zero errors amounts. Findings: The sum of normal and gamma distribution can be useful for modeling audit errors. Originality/value: In this paper, the method of moments is proposed to estimate mixtures of probability distribution, and we derive a formulation of the probability distribution of the sum of a normally distributed random variable and one with gamma distribution. This research could be useful in financial auditing.
Źródło:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska; 2020, 143; 275-284
1641-3466
Pojawia się w:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Finite-Sized Aperture on the Performance of Differential Multihop DF-FSO Network
Autorzy:
Agarwal, Deepti
Yadav, Poonam
Powiązania:
https://bibliotekanauki.pl/articles/2200711.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
differencial modulation
K-distribution
Free space optics (FSO)
Average bit error rate (BER)
Decode and forward relaying
pointing error
Opis:
This paper investigates the differential binary modulation for decode-and-forward (DF) based relay-assisted free space optical (FSO) network under the effect of strong atmospheric turbulence together with misalignment error (ME). The atmospheric fading links experience K-distributed turbulence. First we derive novel closed form expression for average bit error rate (BER) and outage probability (OP) in terms of Meijer’s G function. Further, the OP of differential DF-FSO system with multiple relays is derived. We also analyze the asymptotic performance for the sake of getting the order of diversity and the coding gain. The power allotment term is utilized to examine the effect of different power allotment techniques on BER and OP. The simulation results have been used to validate the derived analytical results.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 4; 807--813
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of AC field distribution on impedance of the conductivity cell
Autorzy:
Mikhal, A. A.
Warsza, Z. L.
Powiązania:
https://bibliotekanauki.pl/articles/114302.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
measurement
electrolytic conductivity
electrical field
error
Opis:
The АС impedance model of a liquid conductivity has been developed to assess the influence of electromagnetic vector potential. It has been proved that the field in a liquid conductor is quasi-static. Approximation error, even taken for very concentrated solutions (e.g. sea water), does not exceed 0.01 ppm. The calculation of resistance of the four-electrode cell is given with the account of Ampere's circuit law. Two types of errors are defined: DC error due to finite thickness of electrodes, and AC error due to presence of displacement currents when using an impedance model.
Źródło:
Measurement Automation Monitoring; 2015, 61, 11; 521-525
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A physical model of separation process by means of jigs
Autorzy:
Surowiak, A.
Brozek, M.
Powiązania:
https://bibliotekanauki.pl/articles/110846.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
jigging process
physical model
Maxwell distribution
probable error
imperfection
Opis:
In the case of ideal separation of minerals, partition into products is conducted according to a specific partition feature which is, for instance, the density of raw material. Usually, enrichment in a jig is described by means of the particle density as a partition feature. However, the degree of particle loosening in the jig's bed is influenced by, among others, the particle free settling velocity. After some time of the pulsating movement duration, particle segregation along the vertical axis according to the settling velocity will occur. It can be said that the particle free settling velocity constitutes a feature characteristic of the feed heterogeneous in terms of physical and geometric properties in the jigging process. In the article on the basis of heuristic considerations, a physical model of the partition function (recovery of the i-th fraction), in which interactions between particles in the working bed of the jig are taken into account, is derived. A cause of the formation of the mechanism of particle dispersion around equilibrium layers is given and the accuracy of particle partition for a narrow size fraction in two variations, i.e. in conditions when a partition feature is, accordingly, the particle density and settling velocity, is calculated. These calculations allowed for the analysis of causes of process and inherent dispersion formation which takes place during the jigging process.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 228-243
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ROBUSTNESS OF TWEEDIE MODEL OF RESERVES WITH RESPECT TO DISTRIBUTION OF SEVERITY OF CLAIMS
Autorzy:
Boratyńska, Agata
Juszczak, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/453337.pdf
Data publikacji:
2015
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
loss reserves
Tweedie model
Poisson and gamma distribution
ε-contamination
generalized linear model
mean square error
bias
prediction
Opis:
The aim of the work is to discuss the robustness of estimation procedures and robustness of prediction in Tweedie's compound Poisson model. This model is applied to the claim reserving problem. The quality of parameter estimators and predictors is studied when the distribution of severity of claims is disturbed. The ε-contamination class of distributions is considered. The example, where errors of estimators are large is presented. The simulation methods, using the R programming environment, are applied.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2015, 16, 1; 53-74
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On statistical estimations of vehicle speed measurements
Autorzy:
Skeivalas, Jonas
Paršeliūnas, Eimuntas
Putrimas, Raimundas
Šlikas, Dominykas
Powiązania:
https://bibliotekanauki.pl/articles/220723.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vehicle speed
speedometer
maximum permissible error
skew normal distribution
errors
Opis:
The accuracy of vehicle speed measured by a speedometer is analysed. The stress on the application of skew normal distribution is laid. The accuracy of measured vehicle speed depends on many error sources: construction of speedometer, measurement method, model inadequacy to real physical process, transferring information signal, external conditions, production process technology etc. The errors of speedometer are analysed in a complex relation to errors of the speed control gauges, whose functionality is based on the Doppler effect. Parameters of the normal distribution and skew normal distribution were applied in the errors analysis. It is shown that the application of maximum permissible errors to control the measuring results of vehicle speed gives paradoxical results when, in the case of skew normal distribution, the standard deviations of higher vehicle speeds are smaller than the standard deviations of lower speeds. In the case of normal distribution a higher speed has a greater standard deviation. For the speed measurements by Doppler speed gauges it is suggested to calculate the vehicle weighted average speed instead of the arithmetic average speed, what will correspond to most real dynamic changes of the vehicle speed parameters.
Źródło:
Metrology and Measurement Systems; 2019, 26, 3; 551-559
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of Step-Size Distribution Optimization Used in S-SSFM Simulations of WDM Systems
Autorzy:
Jaworski, M.
Powiązania:
https://bibliotekanauki.pl/articles/308958.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
local error method
logarithmic step
simulation
split-step Fourier method
WDM
Opis:
Brief review of methods used for simulation of signal propagation in wavelength division multiplexed (WDM)links is presented. We propose two novel methods of stepsize distribution optimization used to improve symmetrized split step Fourier method (S-SSFM) numerical efficiency: presimulated local error S-SSFM (PsLE S-SSFM) and modified logarithmic (ML S-SSFM). The PsLE S-SSFM contains two stages: in the initial stage step-size distribution optimization is carried out by combining local error method and presimulation with signal spectrum averaging; in the second stage conventional SSFM is used by applying optimal step-size distribution obtained in the initial stage. The ML S-SSFMis generalization of logarithmic method proposed to suppress spurious FWM tones, in which a slope of logarithmic step-size distribution is optimized. Overall time savings exceed 50%, depending of a simulated system scenario.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 1; 44-50
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative BER Analysis of Free Space Optical System Using Wavelength Diversity over Exponentiated Weibull Channel
Autorzy:
Shah, Dhaval
Joshi, Hardik
Kothari, Dilipkumar
Powiązania:
https://bibliotekanauki.pl/articles/2055211.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bit error rate
exponentiated weibull distribution
free space optics
FSO
wavelingth diversity
optimal combining
Opis:
Atmospheric turbulence is considered as major threat to Free Space Optical (FSO) communication as it causes irradiance and phase fluctuations of the transmitted signal which degrade the performance of FSO system. Wavelength diversity is one of the techniques to mitigate these effects. In this paper, the wavelength diversity technique is applied to FSO system to improve the performance under different turbulence conditions which are modeled using Exponentiated Weibull (EW) channel. In this technique, the data was communicated through 1.55 µm, 1.31 µm, and 0.85 µm carrier wavelengths. Optimal Combining (OC) scheme has been considered to receive the signals at receiver. Mathematical equation for average BER is derived for wavelength diversity based FSO system. Results are obtained for the different link length under different turbulence conditions. The obtained average BER results for different turbulence conditions characterized by EW channel is compared with the published result of average BER for different turbulence which is presented by classical channel model. A comparative BER analysis shows that maximum advantage of wavelength diversity technique is obtained when different turbulence conditions are modeled by EW channel.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 4; 665--672
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Selective-Decode and Forward Relaying Protocol over κ-µ Fading Channel Distribution
Autorzy:
Shankar, Ravi
Bhardwaj, Lokesh
Mishra, Ritesh Kumar
Powiązania:
https://bibliotekanauki.pl/articles/309566.pdf
Data publikacji:
2020
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
channel fading
channel state information
relaying protocol
selective decode and forward
symbol error rate
Opis:
In this work, the performance of selective-decode and forward (S-DF) relay systems over κ-µ fading channel conditions is examined in terms of probability density function (PDF), system model and cumulative distribution function (CDF) of the κ-µ distributed envelope, signal-to-noise ratio and the techniques used to generate samples that rely on κ-µ distribution. Specifically, we consider a case where the sourceto-relay, relay-to-destination and source-to-destination link is subject to independent and identically distributed κ-µ fading. From the simulation results, the enhancement in the symbol error rate (SER) with a stronger line of sight (LOS) component is observed. This shows that S-DF relaying systems may perform well even in non-fading or LOS conditions. Monte Carlo simulations are conducted for various fading parameter values and the outcomes turn out to be a close match for theoretical results, which validates the derivations made.
Źródło:
Journal of Telecommunications and Information Technology; 2020, 1; 21-30
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bayesian and Non Bayesian Method of Estimation of Scale Parameter of Gamma Distribution under Symmetric and Asymmetric Loss Functions
Autorzy:
Gupta, Isha
Gupta, Rahul
Powiązania:
https://bibliotekanauki.pl/articles/1177726.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Bayes Estimator
Linex Loss Function
Precautionary Loss Function
Risk Function
Squared Error Loss Function
Opis:
In this investigation, we consider Bayesian and Non-Bayesian estimation problems of unknown scale parameter of Gamma distribution assuming the shape parameter as known and derive Bayes and Classical (Non-Bayes) estimators of the scale parameter. Bayes estimators are obtained under symmetric (squared error) and asymmetric (linex and precautionary) loss functions using a non-informative prior. The risk efficiency of Bayes estimators is also obtained under these loss functions. Finally, the simulation study is done to compare the performance of these estimators using MATLAB software.
Źródło:
World Scientific News; 2018, 101; 172-191
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FSO system performance analysis based on novel Gamma–Chi-square irradiance PDF model
Autorzy:
Todorović, Jelena
Spalević, Petar
Panić, Stefan
Milosavljević, Bojana
Gligorijević, Milan
Powiązania:
https://bibliotekanauki.pl/articles/2033970.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
free space optics
FSO
Gamma-Chi-square distribution
atmospheric turbulence
pointing error
on-off keying
OOK
Opis:
In order to provide a novel analytically traceable free space optics (FSO) channel model for describing turbulence based irradiance fluctuations, following basic scintillation theory principles, we have derived closed-form expression for probability density function (PDF) of a new statistical Gamma–Chi-square model. Further, capitalizing on provided model, error performances of FSO system over on-off keying (OOK) transmission scheme both in the presence of atmospheric turbulence and misalignment fading (pointing error) is investigated. For both cases, the average bit error rate (ABER) at the receiving side of the system is determined in an analytically closed form. The results are graphically presented in order to analyze the impact of different levels of turbulence, as well as other relevant parameters, on the quality of the received signal in the OOK modulated FSO system.
Źródło:
Optica Applicata; 2021, 51, 3; 335-348
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A modified robust confidence interval for the population mean of distribution based on deciles
Autorzy:
Abu-Shawiesh, Moustafa Omar Ahmed
Sinsomboonthong, Juthaphorn
Kibria, Bhuiyan Mohammad Golam
Powiązania:
https://bibliotekanauki.pl/articles/2034111.pdf
Data publikacji:
2022-03-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
robust confidence interval
decile mean
decile mean standard deviation
decile mean standard error
Monte Carlo simulation
Opis:
The confidence interval is an important statistical estimator of population location and dispersion parameters. The paper considers a robust modified confidence interval, which is an adjustment of the Student’s t confidence interval based on the decile mean and decile standard deviation for estimating the population mean of a skewed distribution. The efficiency of the proposed interval estimator is evaluated on the basis of an extensive Monte Carlo simulation study. The coverage ratio and average width of the proposed confidence interval are compared with certain existing and widely used confidence intervals. The simulation results show that, in general, the proposed interval estimator’s performance is highly effective. For illustrative purposes, three real-life data sets are analyzed, which, to a certain extent, support the findings obtained from the simulation study. Thus, we recommend that practitioners use the robust modified confidence interval for estimating the population mean when the data are generated by a normal or skewed distribution.
Źródło:
Statistics in Transition new series; 2022, 23, 1; 109-128
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł

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