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Wyświetlanie 1-23 z 23
Tytuł:
Estimating the population mean using a continuous sampling design dependent on an auxiliary variable
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/1059051.pdf
Data publikacji:
2020-12-04
Wydawca:
Główny Urząd Statystyczny
Tematy:
continuous sampling design
Horvits-Thompson estimator
inclusion density
sampling scheme
bivariate gamma distribution
ratio estimator
Opis:
Continuous distribution of variables under study and auxiliary variables are considered. The purpose of the paper is to estimate the mean of the variable under study using a sampling design which is dependent on the observation of a continuous auxiliary variable in the whole population. Auxiliary variable values observed in this population allow to estimate the inclusion density function of the sampling design. The variance of the continuous version of the Horvitz-Thompson estimator under the proposed sampling design is compared with the variance of the mean of a simple random sample. The accuracy of the estimation strategies is analysed by means of simulation experiments.
Źródło:
Statistics in Transition new series; 2020, 21, 5; 1-16
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating the population mean using a complex sampling design dependent on an auxiliary variable
Autorzy:
Chaudhuri, Arijit
Samaddar, Sonakhya
Powiązania:
https://bibliotekanauki.pl/articles/2034118.pdf
Data publikacji:
2022-03-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
Des Raj and symmetrized Des Raj estimator and associated variance
Hartley-Ross
Horvitz-Thompson
Lahiri-Midzuno-Sen
Murthy
Rao-Hartley-Cochran procedures vis-a-vis SRSWOR and SRSWR
Hansen-Hurwitz estimation and variance
Opis:
In surveying finite populations, the simplest strategy to estimate a population total without bias is to employ Simple Random Sampling (SRS) with replacement (SRSWR) and the expansion estimator based on it. Anything other than that including SRS Without Replacement (SRSWOR) and usage of the expansion estimator is a complex strategy. We examine here (1) if from a complex sample at hand a gain in efficiency may be unbiasedly estimated comparing the ”rival population total-estimators” for the competing strategies and (2) how suitable model-expected variances of rival estimators compete in magnitude as examined numerically through simulations.
Źródło:
Statistics in Transition new series; 2022, 23, 1; 39-54
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonresponse Bias in The Survey of Youth Understanding of Science and Technology in Bogotá
Autorzy:
Castellanos, Edgar Mauricio Bueno
Powiązania:
https://bibliotekanauki.pl/articles/466054.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Tematy:
Sampling design
nonresponse bias
calibration
Opis:
The Colombian Observatory of Science and Technology -OCyT- developed, in 2009, a survey about understanding of Science and Technology in students of high school in Bogotá, Colombia. The sampling design was stratified according to the nature of school (public or private). Two sources of unit nonresponse were detected. The first one corresponds to schools that did not allowed to collect information. The second source corresponds to students who did not assist during the days when survey was applied. Estimates were obtained through two different approaches. Results obtained in both cases do not show visible differences when estimating ratios; even though, some great differences were observed when estimating totals. Results obtained using the second approach are believed to be more reliable because of the methodology used to handle item nonresponse.
Źródło:
Statistics in Transition new series; 2012, 13, 1; 79-94
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric prediction of finite population total under Informative sampling and nonignorable nonresponse
Autorzy:
Abdulhakeem, Eideh
Powiązania:
https://bibliotekanauki.pl/articles/1358422.pdf
Data publikacji:
2020-03-23
Wydawca:
Główny Urząd Statystyczny
Tematy:
response distribution
nonignorable nonresponse
informative sampling design
Opis:
In this paper, we combine two methodologies used in the model-based survey sampling, namely the prediction of the finite population total, named T, under informative sampling and full response, see Sverchkov and Pfeffermann (2004), and the prediction of T with a noninformative sampling design and the nonignorable nonresponse mechanism, see Eideh (2012). The former approach involves the dependence of the first order inclusion probabilities on the study variable, while the latter involves the dependence of the probability of nonresponse on unobserved or missing observations. The main aim of the paper is to consider how to account for the joint effects of informative sampling designs and notmissing- at-random response mechanism in statistical models for complex survey data. For this purpose, theoretically, we use the response distribution and relationships between the moments of the superpopoulation, the sample, sample-complement, response, and nonresponse distributions for the prediction of finite population totals, see Eideh (2016). The derived parametric predictors of T use the observation for the response set of the study variable or variable of interest, values of auxiliary variables and their population totals, sampling weights, and propensity scores. An interesting outcome of the T study is that most predictors known from model-based survey sampling can be derived as a special case from this general theory, see Chambers and Clark (2012).
Źródło:
Statistics in Transition new series; 2020, 21, 1; 13-35
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Order Statistics of Auxiliary Variable to Estimation the Population Mean
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/465810.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Tematy:
Order statistic
sample quantile
auxiliary variable
sampling scheme
sampling design
concomitant
Opis:
Estimation of the population average in a finite population by means of sampling strategies dependent on an auxiliary variable highly correlated with a variable under study is considered. The sample is drawn with replacement on the basis of the probability distribution of an order statistic of the auxiliary variable. Observations of the variable under study are the values of the concomitant of the order statistic. The mean of the concomitant values is the estimator of a population mean of the variable under study. The expected value and the variance of the estimator are derived. The limit distributions of the considered estimators were considered. Finally, on the basis of simulation analysis, the accuracy of the estimator is considered.
Źródło:
Statistics in Transition new series; 2012, 13, 2; 279-286
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of a Function of Misclassified Binary Data
Autorzy:
Al-Kandari, Noriah M.
Powiązania:
https://bibliotekanauki.pl/articles/973541.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Statystyczny
Tematy:
binary classification
double sampling
finite population sampling
misclassification
linkage error
sampling design
Opis:
We consider the problem of predicting a function of misclassified binary variables. We make an interesting observation that the naive predictor, which ignores the misclassification errors, is unbiased even if the total misclassification error is high as long as the probabilities of false positives and false negatives are identical. Other than this case, the bias of the naive predictor depends on the misclassification distribution and the magnitude of the bias can be high in certain cases. We correct the bias of the naive predictor using a double sampling idea where both inaccurate and accurate measurements are taken on the binary variable for all the units of a sample drawn from the original data using a probability sampling scheme. Using this additional information and design-based sample survey theory, we derive a biascorrected predictor. We examine the cases where the new bias-corrected predictors can also improve over the naive predictor in terms of mean square error (MSE).
Źródło:
Statistics in Transition new series; 2016, 17, 3; 429-448
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zwiększenie efektywności inwentaryzacji lasu metodą losowania warstwowego
Improving effectiveness of forest inventory by stratified sampling
Autorzy:
Banaś, J.
Drozd, M.
Zięba, S.
Bujoczek, L.
Powiązania:
https://bibliotekanauki.pl/articles/986979.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
inwentaryzacja lasu
losowanie warstwowe
poprawa efektywnosci
sampling design
inventory precision
stratified sampling
Opis:
The purpose of the stratification is to group stands basing on the homogeneity of the measured feature. During periodic forest inventory in Poland, strata are created on the basis of age and the main species in stand within the boundary of forest district. In this work an improvement of distinguishing the strata during the forest inventory is presented. Three variants are considered: (1) distinguishing homogeneous strata in boundary of the whole forest district, not separately in forest subdistricts, (2) splitting species−aged strata into homogeneous substrata with respect to site quality, and (3) dividing strata of stands in the regeneration class with respect to stand density. Study was conducted in four mountain forest districts located in the Kłodzko Basin (SW Poland). Total area of these stands amounted to 43,052 ha, where 6,648 sample plots were established during the periodic inventory. ANOVA was used to test significance of the differences in tree volume and to assess variability reducing in distinguished substrata. Results indicated that in stands with age up to 70 years mean volume of trees on the sample plot does not differ significantly between sites, but in older stands difference was significant. Dividing age−species strata of stands older than 70 years into substrata according to site conditions influenced reduction of volume variability from 10 to 57% in newly created substrata. Dividing strata consisted of stands in regeneration class according to stand density index allowed to decrease the volume variability from 9 to 20%. Mean volume of trees in stands on similar sites does no differ significantly between subdistricts in the same forest district. Strata distinguished within the whole forest district are bigger and represented by more sample plots than on the subdistrict level, which significantly reduced standard error of volume and improved effectiveness of stratification in forest inventory.
Źródło:
Sylwan; 2017, 161, 10; 804-811
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Limit Distribution of Horvitz-Thompson Statistic under Poisson Sampling Design
O rozkładzie granicznym statystyki Horvitza-Thompsona dla próby dobieranej zgodnie z planem losowania Poissona
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/964120.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Badania ankietowe
Wnioskowanie statystyczne
Wykładniki Lapunowa
Inferential statistics
Lyapunov exponents
Questionnaire survey
Opis:
W pracy na podstawie znanego twierdzenia centralnego Lapunowa jest wyprowadzany rozkład graniczny prawdopodobieństwa znanej statystyki Horvitza-Thompsona (HT). Okazało się, że jeśli określane przez plan losowania Poissona prawdopodobieństwa wylosowania do próby poszczególnych elementów populacji spełniają pewne założenia oraz rozmiar populacji rośnie nieograniczenie, to rozkład standardowej postaci statystyki HT zmierza do rozkładu normalnego standardowego. Taki sam wynik otrzymano przy dodatkowym założeniu narzuconym na prawdopodobieństwa wylosowania elementów populacji do próby, gdy w standardowej postaci statystyki HT jej odchylenie standardowe zastąpimy przez pierwiastek z nieobciążonego estymatora tej wariancji. Rezultaty pracy znajdują zastosowania np. w pewnych typach badań ankietowych, a w szczególności internetowych, wykorzystujących wnioskowanie statystyczne, czyli estymację przedziałową lub testowanie hipotez statystycznych.
Źródło:
Studia Ekonomiczne; 2013, 133; 61-70
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Conditional Simple Random Sample
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/465622.pdf
Data publikacji:
2014
Wydawca:
Główny Urząd Statystyczny
Tematy:
simple random sample
conditional sampling design
sampling scheme
inclusion probabilities
auxiliary variable
order statistics
Opis:
Estimation of the population average in a finite and fixed population on the basis of the conditional simple random sampling design dependent on order statistics of the auxiliary variable is studied. The sampling scheme implementing the sampling design is proposed. The inclusion probabilities are derived. The well known Horvitz-Thompson statistic under the conditional simple random sampling designs is considered as the estimator of population mean. Moreover, it was shown that the Horvitz-Thompson estimator under some particular cases of the conditional simple random sampling design is more accurate than the ordinary mean from the simple random sample.
Źródło:
Statistics in Transition new series; 2014, 15, 4; 525-534
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Population Sampling: A Model-Design Synthesis
Autorzy:
Ghosh, Malay
Powiązania:
https://bibliotekanauki.pl/articles/465975.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Opis:
The paper considers a general class of Bayes estimators for estimating the finite population mean which also achieve design consistency. Some exact results are given where Bayes estimators agree with the Horvitz-Thompson or ratio estimators. For a wider class of priors, asymptotic mathematical equivalence of Bayes estimators with the above estimators is provided.
Źródło:
Statistics in Transition new series; 2012, 13, 2; 235-242
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability and efficiency of the D, E, S, A-optimal sampling schedule design
Autorzy:
Kalicka, R.
Bochen, D.
Powiązania:
https://bibliotekanauki.pl/articles/1954507.pdf
Data publikacji:
1999
Wydawca:
Politechnika Gdańska
Tematy:
modelling
optimal sampling schedules
various criteria
Opis:
Due to the sharp practical and ethical constraints imposed on medical measurements, the parameter estimation procedure that is designed for diagnosis and therapy is often a difficult problem. When blood sampling provides the data, the number of samples and the measurement interval should be minimised. We have implemented D (determinant), E (eigenvalue), S (sensitivity) and A (trace) optimal sampling schedules (OSSs). These OSSs have minimal size, which means that the number of samples is equal to the number of model parameters that are being estimated. Setting up the results of the D, E, S and A approaches allows us to compare their efficiency and usefulness. Illustrative examples are presented.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1999, 3, 4; 453-464
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sampling Designs Proportionate to Sum of Two Order Statistics of Auxiliary Variable
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/465790.pdf
Data publikacji:
2013
Wydawca:
Główny Urząd Statystyczny
Tematy:
sampling design
order statistic
sample quantile
auxiliary variable
Horvitz-Thompson statistic
inclusion probabilities
sampling scheme
ratio estimator
Opis:
In this paper the case of a conditional sampling design proportional to the sum of two order statistics is considered. Several strategies including the Horvitz-Thompson estimator and ratio-type estimators are discussed. The accuracy of these estimators is analyzed on the basis of computer simulation experiments.
Źródło:
Statistics in Transition new series; 2013, 14, 2; 231-248
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performing quantiles in multiple regression sampling strategy
Ocena wartości przeciętnej za pomocą regresyjnej strategii losowania wykorzystującej kwantyle zmiennej pomocniczej
Autorzy:
Wywiał, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/907013.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
sampling design
order statistic
sample quantile
auxiliary variable
Horvitz-Thompson statistic
inclussion probabilities
sampling scheme
regression estimator
Opis:
Estimation of the population average in a finite population by means of sampling strategy dependent on the sample quantile of an auxiliary variables is considered. The sampling design is proportionate to the determinant of the matrix dependent on some quantiles of an auxiliary variables. The sampling scheme implementing the sampling design is proposed. The derived inclusion probabilities are applied to estimation the population mean using the well known Horvitz-Thompson estimator. Moreover, the regression estimator is defined as the function of the coefficient dependent on the quantiles of the auxiliary variables. The properties of this estimator under the above defined sampling design are studied. The considerations are supported by empirical examples.
Problem oceny wartości średniej z wykorzystaniem danych o wszystkich wartościach cech pomocniczych jest rozważany. W tym celu znany estymator regresyjny zależny od wielu zmiennych pomocniczych jest wykorzystywany. W odróżnieniu od zwykłego podejścia znanego w metodzie reprezentacyjnej do oceny parametrów regresji są wykorzystywane kwantyle jednej ze zmiennych dodatkowych. Otrzymane na tym polu wyniki są adoptowane do konstrukcji predytorów wartości średniej w nadpopulacji. Wyprowadzono również wariancje różnych odmian proponowanych predykatorów.
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:
Estimation of Domain Means on The Basis of Strategy Dependent on Depth Function of Auxiliary Variables’ Distribution
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/465849.pdf
Data publikacji:
2011
Wydawca:
Główny Urząd Statystyczny
Tematy:
sampling design
order statistic
auxiliary variable
sampling scheme
Horvitz-Thompson estimator
small area estimation
area sampling
depth function
Opis:
The paper deals with the problem of estimation of a domain means in a finite and fixed population. We assume that observations of a multidimensional auxiliary variable are known in the population. The proposed estimation strategy consists of the well known Horvitz-Thompson estimator and the non-simple sampling design dependent on a synthetic auxiliary variable whose observations are equal to the values of a depth function of the auxiliary variable distribution. The well known spherical and Mahalanobis depth functions are considered. A sampling design is proportionate to the maximal order statistic determined on the basis of the synthetic auxiliary variable observations in a simple sample drawn without replacement. A computer simulation analysis leads to the conclusion that the proposed estimation strategy is more accurate for domain means than the well known simple sample means.
Źródło:
Statistics in Transition new series; 2011, 12, 1; 127-138
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Mean on The Basis of Conditional Simple Random Sample
Autorzy:
Wywiał, Janusz L.
Powiązania:
https://bibliotekanauki.pl/articles/466050.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Statystyczny
Tematy:
conditional sampling design
order statistic
concomitant
sample quantile
auxiliary variable
Horvitz-Thompson statistic
inclusion probabilities
sampling scheme
ratio estimator
Opis:
Estimation of the population mean in a finite and fixed population on the basis of the conditional simple random sampling design dependent on order statistics (quantiles) of an auxiliary variable is considered. Properties of the well-known Horvitz-Thompson and ratio type estimators as well as the sample mean are taken into account under the conditional simple random sampling designs. The considered examples of empirical analysis lead to the conclusion that under some additional conditions the proposed estimation strategies based on the conditional simple random sample are usually more accurate than the mean from the simple random sample drawn without replacement.
Źródło:
Statistics in Transition new series; 2016, 17, 3; 411-428
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation analysis of accuracy estimation of population mean on the basis of regression type strategy dependent on order statistic of auxiliary variable
Autorzy:
Wywiał, Janusz L
Powiązania:
https://bibliotekanauki.pl/articles/658095.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
sampling design
order statistic
auxiliary variable
sampling scheme
estimation
strategy
accuracy comparison
relative efficiency
regression estimator
Horvitz-Thomson estimator
Opis:
Problem dotyczy oceny wartości średnie (globalnej) zmiennej w populacji ustalonej I skończonej. Zakład się, że z góry są znane w populacji wartości dodatniej zmiennej pomocniczej. Do estymacji użyto strategia kwantylowej zależnej m.in. od planu losowania proporcjonalnego do nieujemnej funkcji kwantyla z próby zmiennej pomocniczej. Ponadto, brano pod uwagę estymator Horvitza- Thompsona oraz estymator ilorazowy. Porównanie dokładności przeprowadzono na podstawie symulacji komputerowej.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2011, 255
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic statistical design of variable sampling interval X̅ control chart based on surrogate variable using genetic algorithms
Autorzy:
Lee, T.-H.
Hong, S.-H.
Kwon, H.-M.
Lee, M.
Powiązania:
https://bibliotekanauki.pl/articles/406970.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
economic design
surrogate variable
variable sampling interval
TRISO Fuel
genetic algorithms
Opis:
In many cases, a X̅ control chart based on a performance variable is used in industrial fields. Typically, the control chart monitors the measurements of a performance variable itself. However, if the performance variable is too costly or impossible to measure, and a less expensive surrogate variable is available, the process may be more efficiently controlled using surrogate variables. In this paper, we present a model for the economic statistical design of a VSI (Variable Sampling Interval) X̅ control chart using a surrogate variable that is linearly correlated with the performance variable. We derive the total average profit model from an economic viewpoint and apply the model to a Very High Temperature Reactor (VHTR) nuclear fuel measurement system and derive the optimal result using genetic algorithms. Compared with the control chart based on a performance variable, the proposed model gives a larger expected net income per unit of time in the long-run if the correlation between the performance variable and the surrogate variable is relatively high. The proposed model was confined to the sample mean control chart under the assumption that a single assignable cause occurs according to the Poisson process. However, the model may also be extended to other types of control charts using a single or multiple assignable cause assumptions such as VSS (Variable Sample Size) X̅ control chart, EWMA, CUSUM charts and so on.
Źródło:
Management and Production Engineering Review; 2016, 7, 4; 54-64
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new OSS design based on parameter sensitivity to changes in measurements
Autorzy:
Kalicka, R.
Bochen, D.
Powiązania:
https://bibliotekanauki.pl/articles/969953.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optimal sampling schedule
sensitivity criterion
Opis:
As a result of the severe practical and ethical constraints imposed on medical measurements, the parameter estimation procedure designed for diagnosis and therapy is often a difficult problem. When blood sampling provides the data, the number of samples and the observation interval should be minimized. Designing an experiment for parameter estimation requires a step known as quantitative experiment design, usually preceded by a step called qualitative experiment design. The latter answers if a model is identifiable under particular experimental conditions. The former is suitable for the purpose of obtaining the maximum information from the data to be collected. An experiment design is based on the optimization of a suitable criterion formulated with respect to the analyzed variables of the experiment (input shape, sampling schedule). This paper considers sampling schedule design. New criteria for new optimal sampling schedules (OSS) have been formulated on the basis of sensitivity function. These are referred to as S-OSS and RS-OSS designs. The results of optimization for both criteria are compared with the result obtained with a reputable established D-optimal design based on the Fisher information matrix. By showing the results of S-OSS and RS-OSS design we can present the reliability and efficiency of the new criteria in comparison to D-OSS design. Illustrative examples are presented.
Źródło:
Control and Cybernetics; 2006, 35, 2; 385-406
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal allocation for equal probability two-stage design
Autorzy:
Molefe, Wilford
Powiązania:
https://bibliotekanauki.pl/articles/2156993.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
sample designs
optimal allocation
composite estimation
mean squared error
two-stage sampling
simple random sampling without replacement
Opis:
This paper develops optimal designs when it is not feasible for every cluster to be represented in a sample as in stratified design, by assuming equal probability two-stage sampling where clusters are small areas. The paper develops allocation methods for two-stage sample surveys where small-area estimates are a priority. We seek efficient allocations where the aim is to minimize the linear combination of the mean squared errors of composite small area estimators and of an estimator of the overall mean. We suggest some alternative allocations with a view to minimizing the same objective. Several alternatives, including the area-only stratified design, are found to perform nearly as well as the optimal allocation but with better practical properties. Designs are evaluated numerically using Switzerland canton data as well as Botswana administrative districts data.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 129-148
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of Wearable EEG Device for Seizures Early Detection
Autorzy:
Gaidar, Viktoriia
Sudakov, Oleksandr
Powiązania:
https://bibliotekanauki.pl/articles/1844635.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
circuit design
statistical sampling
Hilbert-Huang transform
feature selection
Opis:
This paper presents the design of a wearable electroencephalography device and signal processing algorithm for early detection and forecasting of the epileptiform activity. The availability of the examination of functional brain activity for a prolonged period, outside of the hospital facilities, can provide new advantages in early diagnosis and intervention systems. In this study, the low-cost five-channel device is presented. The system consists of two main parts: the data acquisition and transmission units and processing algorithms. In order to create the robust epileptiform pattern recognition approach the application of statistical sampling and signal processing techniques are performed. The discrete wavelet and Hilbert-Huang transforms with principal component analysis are used in order to extract and select a low-dimension feature vector.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 2; 187-192
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ANSDM converters dynamic range design process
Autorzy:
Golański, Ryszard
Godek, Juliusz
Powiązania:
https://bibliotekanauki.pl/articles/1402376.pdf
Data publikacji:
2020
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
delta modulation
non-uniform sampling
SNR
dynamic range
Lambert W function
sampling interval
Maple
modulacja delta
nierównomierne próbkowanie
zakres dynamiczny
funkcja Lamberta
odstęp próbkowania
Opis:
The results of analytic and simulating works proved that for nonstationary sources, the delta converters with adaptive sampling expose higher coding efficiency than the former proposals, based on uniform sampling methods. The knowledge of the sampling interval range and the algorithm of the Nonuniform Sampling Delta Modulation and Adaptive Nonuniform Sampling Delta Modulation allows finding the necessary number of the sampling intervals and their values that maximizes SNR. The total dynamic range of the ANSDM modulator is the product of the dynamic range both from sampling interval and step size adaptation. Due to the high complexity of the calculations, the ANSDMsoft program was developed to support computing. All computational works were carried out using the Maple environment. Maple allows to solve complex mathematical functions and display their results in a simple way. Most importantly, it supports the LambertW function, used in the computing of NSDM or ANSDM modulators parameters. Graphic illustrations of the NSDM and ANSDM modulator dynamic range as a function of the minimum and maximum sampling frequency are presented.
Źródło:
Science, Technology and Innovation; 2020, 10, 3; 1-7
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing sampling parameters of cmm data acquisition for machining error correction of freeform surfaces
Autorzy:
Poniatowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/386245.pdf
Data publikacji:
2018
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
freeform surface
machining error correction
coordinate measurement
measurement parameters
design of experiment technique
Opis:
An optimization study using the design of experiment technique is described, in which the surface profile height of a freeform surface, determined in coordinate measurements, is the response variable. The control factors are coordinate sampling parameters, i.e. the sampling grid size and the measuring tip diameter. As a result of the research, an optimal combination of these parameters was found for surface mapping with acceptable measurement uncertainty. The presented study is the first stage of optimization of machining error correction for the freeform surface and was intended to take into account mechanical-geometric filtration of surface irregularities caused by these geometrical parameters. The tests were carried out on a freeform workpiece milled with specific machining parameters, Ra of the surface roughness was 1.62 μm. The search for the optimal combination of parameters was conducted using Statistica software.
Źródło:
Acta Mechanica et Automatica; 2018, 12, 4; 265-269
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekonomiczny model badań niezawodnościowych goi
Economic design for goi reliability tests
Autorzy:
Yang, S. F.
Chien, K. W-T
Powiązania:
https://bibliotekanauki.pl/articles/301087.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
minimalny rozmiar próbki
badanie V-Ramp
GOI (Nienaruszony Stan Tlenku Bramkowego)
gęstość defektów
próbkowanie losowe
rozkład dwumianowy
granice przedziału ufności
minimum sample size
V-Ramp test
GOI (Gate Oxide Integrity)
defect density
random sampling
binomial distribution
confidence bounds
Opis:
This paper studies the methods and guidelines in minimum sample size determination provided by JEDEC/ FSA joint publication and points out their drawbacks, inconsistency, and misguidance. We provide an exact method and easy-to-use numerical solution by extending JEDEC's formula to any allowed failure number, target defect density, and confi dence level. Important guidelines are also provided for reliability practitioners to reduce possible errors resulting from imperfect sampling procedures and to avoid mistakes in defect density evaluation against a target defect density (D0). Our proposed method can be applied to any reliability tests with the binomial distribution to determine a minimum sample size to save wafers and testing resources.
Niniejsza praca analizuje metody i wytyczne dotyczące wyznaczania minimalnego rozmiaru próbki podane we wspólnej publikacji JEDEC/ FSA, wskazując na ich wady, niekonsekwencje i błędne wskazówki. W artykule podajemy dokładne i łatwe w użyciu rozwiązanie, które rozciąga wzór JEDEC na wszelką dozwoloną liczbę uszkodzeń, dopuszczalną gęstość defektów i poziom ufności. Przedstawiamy również ważne wytyczne dla specjalistów w zakresie niezawodności pozwalające zredukować możliwe błędy wynikające z niedoskonałych procedur próbkowania oraz uniknąć pomyłek w ocenie gęstości defektów względem dopuszczalnej gęstości defektów (D0). Proponowana przez nas metoda może być stosowana we wszelkich testach niezawodnościowych z rozkładem dwumianowym do wyznaczania minimalnego rozmiaru próbki przy oszczędnym użyciu płytek i środków badawczych.
Źródło:
Eksploatacja i Niezawodność; 2010, 2; 79-82
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
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