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Wyszukujesz frazę "sampling," wg kryterium: Temat


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:
Testing of adaptive nonuniform sampling switch algorithm with real-time simulation-in-the-loop
Autorzy:
Janczak, J.
Kondratiuk, M.
Pawluszewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/206431.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
nonuniform sampling
sampled-data control
adaptive nonuniform sampling
Opis:
The study is motivated by the considerations concerning implementation of nonuniform sampling regarding the reallife objects. It is shown that nonuniform adaptive sampling switch algorithm can ensure a reduction in the number of taken samples and does not exert negative influence on the quality of the system control. Experiment was performed with 24VDC permanent magnet motor with encoder as a plant. Signals from the encoder were used for rotational speed calculations. The results of experiment are included.
Źródło:
Control and Cybernetics; 2016, 45, 3; 317-328
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Choice of Methods of Checking on Total Quality Control Costs
Wpływ wyboru metody sprawdzania na całkowite koszty kontroli jakości
Autorzy:
Chmielińska, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/905656.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
statistical quality control
acceptance sampling
acceptance sampling costs
Opis:
Acceptance sampling is commonly used in factories, because it decreases the probability of giving defective batch to the customer. From two distinguished ways of acceptance sampling, more frequently in practice is used an attribute sampling method. The purpose of this article is to emphasize the benefits of using acceptance sampling by variables.
Kontrola odbiorcza jest powszechnie stosowana w przedsiębiorstwach produkcyjnych, gdyż zmniejsza ona prawdopodobieństwo przekazania klientowi wadliwej partii produktów. Z wyróżnionych dwóch sposobów kontroli odbiorczej częściej wykorzystywana w praktyce jest kontrola według oceny alternatywnej. Celem niniejszego artykułu jest podkreślenie korzyści wynikających ze stosowania liczbowych planów kontroli odbiorczej.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2013, 285
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-stage cluster sampling with unequal probability sampling in the first stage and ranked set sampling in the second stage
Autorzy:
Ugwu, Michael C.
Madukaife, Mbanefo S.
Powiązania:
https://bibliotekanauki.pl/articles/2108165.pdf
Data publikacji:
2022-09-14
Wydawca:
Główny Urząd Statystyczny
Tematy:
cluster sampling
population mean estimator
probability proportional to size sampling
ranked set sampling
relative efficiency
Opis:
In this research work we introduce a new sampling design, namely a two-stage cluster sampling, where probability proportional to size with replacement is used in the first stage unit and ranked set sampling in the second in order to address the issue of marked variability in the sizes of population units concerned with first stage sampling. We obtained an unbiased estimator of the population mean and total, as well as the variance of the mean estimator. We calculated the relative efficiency of the new sampling design to the two-stage cluster sampling with simple random sampling in the first stage and ranked set sampling in the second stage. The results demonstrated that the new sampling design is more efficient than the competing design when a significant variation is observed in the first stage units.
Źródło:
Statistics in Transition new series; 2022, 23, 3; 199-214
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variance estimation in stratified adaptive cluster sampling
Autorzy:
Yasmeen, Uzma
Noor-ul-Amin, Muhammad
Hanif, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2034098.pdf
Data publikacji:
2022
Wydawca:
Główny Urząd Statystyczny
Tematy:
variance estimator
stratified sampling
stratified adaptive cluster sampling (SACS)
Opis:
In many sampling surveys, the use of auxiliary information at either the design or estimation stage, or at both these stages is usual practice. Auxiliary information is commonly used to obtain improved designs and to achieve a high level of precision in the estimation of population density. Adaptive cluster sampling (ACS) was proposed to observe rare units with the purpose of obtaining highly precise estimations of rare and specially clustered populations in terms of least variances of the estimators. This sampling design proved to be more precise than its more conventional counterparts, including simple random sampling (SRS), stratified sampling, etc. In this paper, a generalised estimator is anticipated for a finite population variance with the use of information of an auxiliary variable under stratified adaptive cluster sampling (SACS). The bias and mean square error expressions of the recommended estimators are derived up to the first degree of approximation. A simulation study showed that the proposed estimators have the least estimated mean square error under the SACS technique in comparison to variance estimators in stratified sampling.
Źródło:
Statistics in Transition new series; 2022, 23, 1; 173-184
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial sampling methods modified by model use
Autorzy:
Bąk, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/1054565.pdf
Data publikacji:
2021-06-04
Wydawca:
Główny Urząd Statystyczny
Tematy:
spatial sampling
drawn-by-drawn sampling
kriging
employees distribution
Opis:
Recent years have seen an intensive development in the field of spatial sampling methods, which generally focus on a balanced distribution of the sample in space. Adaptive sampling methods constitute another dynamic direction in the sampling theory. The issue raised in this article involves the combination of these directions. Five of the commonly known spatial sampling methods have been analysed. The experiment was designed to include statistical model in the sampling procedure. As in the case of adaptive methods, it serves to modify drawing probabilities during sampling. The necessary theory of this sampling modification has been developed and presented. An experiment using artificial data was conducted in order to analyse the efficiency of the model modification in comparison with the primary methods.
Źródło:
Statistics in Transition new series; 2021, 22, 2; 143-154
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-phase power electronics inverters
Autorzy:
Gwóźdź, M.
Powiązania:
https://bibliotekanauki.pl/articles/97361.pdf
Data publikacji:
2011
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
inverter
Generalized Sampling Expansion
Whittaker-Kotelnikov-Shannon sampling theorem
WKS
Opis:
Dynamic changes of parameters of energy sources and receivers are reasons that decrease exactitude of output signals towards reference signals. To improve these parameters more advanced solutions of power electronics systems are necessary. Ones of possible solutions are a sub-phase inverters. The output quantity regulator there is based on Generalized Sampling Expansion, being crucial extension of Whittaker-Kotelnikov-Shannon sampling theorem. Wide-band power electronics current source with regulator based on that extension is analyzed further.
Źródło:
Computer Applications in Electrical Engineering; 2011, 9; 190-199
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonuniform Spatial Sampling in a Ground-Based Noise SAR
Autorzy:
Maślikowski, Ł.
Misiurewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/226510.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonuniform sampling
noise radar
synthetic aperture
radar (SAR)
compressive sampling
Opis:
The paper presents an idea of nonuniform spatial sampling applied to a noise synthetic aperture radar. In certain cases it is desirable to limit the number of spatial (alongtrack) domain samples acquired in a SAR radar because of external constraints on sampling frequency or on the overall number of samples – e.g. in order to economy on time or power consumed. Lowering number of samples taken may, however, lead to spatial aliasing and incorrect reconstruction of the image. Nonuniform sampling allows to reduce the aliasing effect and reconstruct the image better. This technique can be applied with standard reconstruction methods, but it works best together with Compressive Sensing reconstruction algorithms. The idea will be verified with an experimental noise SAR built at ISE PW.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 71-75
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new ratio estimator: an alternative to regression estimator in survey sampling using auxiliary information
Autorzy:
Subzar, Mir
Maqbool, S.
Raja, T. A.
Sharma, Prayas
Powiązania:
https://bibliotekanauki.pl/articles/1186907.pdf
Data publikacji:
2019-12-10
Wydawca:
Główny Urząd Statystyczny
Tematy:
simple random sampling
Opis:
The most dominant problem in the survey sampling is to obtain the better ratio estimators for the estimation of population mean or population variance. Estimation theory is enhanced by using the auxiliary information in order to improve on designs, precision and efficiency of estimators. A modified class of ratio estimator is suggested in this paper to estimate the population mean. Expressions for the bias and the mean square error of the proposed estimators are obtained. Both analytical and numerical comparison has shown the suggested estimator to be more efficient than some existing ones. The bias of the suggested estimator is also found to be negligible for the population under consideration, indicating that the estimator is as good the regression estimator and better than the other estimators under consideration.
Źródło:
Statistics in Transition new series; 2019, 20, 4; 181-189
1234-7655
Pojawia się w:
Statistics in Transition new series
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:
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:
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:
An Unexpected Result on Modelling the Behavior of A/D Converters and the Signals They Produce
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2203003.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
modelling
signal
sampling operation
Opis:
In this paper, we show that the signal sampling operation considered as a non-ideal one, which incorporates finite time switching and operation of signal blurring, does not lead, as the researchers would expect, to Dirac impulses for the case of their ideal behavior.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 1; 185--191
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Order of approximation for nonlinear sampling Kantorovich operators in Orlicz spaces
Autorzy:
Costarelli, Danilo
Vinti, Gianluca
Powiązania:
https://bibliotekanauki.pl/articles/745018.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Nonlinear sampling Kantorovich operators, Orlicz spaces, order of approximation, Lipschitz classes, irregular sampling
Opis:
In this paper, we study the rate of approximation for the nonlinear sampling Kantorovich operators. We consider the case of uniformly continuous and bounded functions belonging to Lipschitz classes of the Zygmund-type, as well as the case of functions in Orlicz spaces. We estimate the aliasing errors with respect to the uniform norm and to the modular functional of the Orlicz spaces, respectively. The general setting of Orlicz spaces allows to deduce directly the results concerning the rate of convergence in \(L^p\)-spaces, \(1 \miu p\) < \(\infty\), very useful in the applications to Signal Processing. Others examples of Orlicz spaces as interpolation spaces and exponential spaces are discussed and the particular cases of the nonlinear sampling Kantorovich series constructed using Fej\'er and B-spline kernels are also considered.
Źródło:
Commentationes Mathematicae; 2013, 53, 2
0373-8299
Pojawia się w:
Commentationes Mathematicae
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:
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 the performance of modified EWMA charts using resampling schemes
Autorzy:
Khan, N.
Yasmin, T.
Aslam, M.
Jun, C. -H.
Powiązania:
https://bibliotekanauki.pl/articles/406444.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
repetitive group sampling
multiple dependent state sampling
EWMA statistic
average run length
simulation
Opis:
Two popular sampling schemes have been used to design control charts by means of a modified exponentially weighted moving average (EWMA) statistic. The structures of the proposed charts, using repetitive group sampling and multiple dependent state sampling, have been presented. The values of average run length have been determined by some specified control chart parameters. The performance of the proposed chart was illustrated via a simulation study. The efficiency of the proposed chart has been compared with the existing one. A practical example based on real data was also given to explain the application of the proposed chart in industry.
Źródło:
Operations Research and Decisions; 2018, 28, 3; 29-43
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Effective Estimation Procedures Under Non- Esponse in Two-Phase Successive Sampling
Autorzy:
Singh, G. N.
Khetan, M.
Maurya, S.
Powiązania:
https://bibliotekanauki.pl/articles/465962.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Statystyczny
Tematy:
non-response, successive sampling two-phase sampling
mean square error
optimum replacement strategy
Opis:
This work is designed to assess the effect of non-response in estimation of the current population mean in two-phase successive sampling on two occasions. Sub-sampling technique of non-respondents has been used and exponential methods of estimation under two-phase successive sampling arrangement have been proposed. Properties of the proposed estimation procedures have been examined. Empirical studies are carried out to justify the suggested estimation procedures and suitable recommendations have been made to the survey practitioners.
Źródło:
Statistics in Transition new series; 2016, 17, 2; 163-182
1234-7655
Pojawia się w:
Statistics in Transition new series
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:
Methods for combining probability and nonprobability samples under unknown overlaps
Autorzy:
Savitsky, Terrance D.
Williams, Matthew R.
Gershunskaya, Julie
Beresovsky, Vladislav
Powiązania:
https://bibliotekanauki.pl/articles/31342142.pdf
Data publikacji:
2023-12-07
Wydawca:
Główny Urząd Statystyczny
Tematy:
Survey sampling
Nonprobability sampling
Data combining
Inclusion probabilities
Exact sample likelihood
Bayesian hierarchical modeling
Opis:
Nonprobability (convenience) samples are increasingly sought to reduce the estimation variance for one or more population variables of interest that are estimated using a randomized survey (reference) sample by increasing the effective sample size. Estimation of a population quantity derived from a convenience sample will typically result in bias since the distribution of variables of interest in the convenience sample is different from the population distribution. A recent set of approaches estimates inclusion probabilities for convenience sample units by specifying reference sample-weighted pseudo likelihoods. This paper introduces a novel approach that derives the propensity score for the observed sample as a function of inclusion probabilities for the reference and convenience samples as our main result. Our approach allows specification of a likelihood directly for the observed sample as opposed to the approximate or pseudo likelihood. We construct a Bayesian hierarchical formulation that simultaneously estimates sample propensity scores and the convenience sample inclusion probabilities. We use a Monte Carlo simulation study to compare our likelihood based results with the pseudo likelihood based approaches considered in the literature.
Źródło:
Statistics in Transition new series; 2023, 24, 5; 1-34
1234-7655
Pojawia się w:
Statistics in Transition new series
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:
ADC Emulation on FPGA
Autorzy:
Tabassum, Huma
Prathik BV, Krishna
Hiremath, Sujatha S.
Powiązania:
https://bibliotekanauki.pl/articles/27311968.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ADC
resolution
FPGA
sampling
conversion
Opis:
Analog-to-Digital Converters (ADCs) are devices that transform analog signals into digital signals and are used in various applications such as audio recording, data acquisition, and measurement systems [1]. Prior to the development of actual chip, there is a need for prototyping, testing and verifying the performance of ADCs in different scenarios. Analog macros cannot be tested on an FPGA. In order to ensure the macros function properly, the emulation of the ADC is done first. This is a digital module and can be designed in System Verilog. This paper demonstrates the design of the module on FPGA for Analog to Digital Converter (ADC) emulation. The emulation is done specific to the ADC macro which has programmable resolutions of 12/10/8/6 bit.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 3; 425--430
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended Definitions of Spectrum of a Sampled Signal
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1844508.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spectrum of sample signal
ideal versus non-ideal sampling
modelling of signal sampling process
Opis:
It is shown that a number of equivalent choices for the calculation of the spectrum of a sampled signal are possible. Two such choices are presented in this paper. It is illustrated that the proposed calculations are more physically relevant than the definition currently in use.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 3; 395-401
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter estimation of exponentiated exponential distribution under selective ranked set sampling
Autorzy:
Hassan, Amal S.
Elshaarawy, Rasha S.
Nagy, Heba F.
Powiązania:
https://bibliotekanauki.pl/articles/2156898.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
exponentiated exponential distribution
partial ranked set sampling
neoteric ranked set sampling
maximum likelihood method
Opis:
Partial ranked set sampling (PRSS) is a cost-effective sampling method. It is a combination of simple random sample (SRS) and ranked set sampling (RSS) designs. The PRSS method allows flexibility for the experimenter in selecting the sample when it is either difficult to rank the units within each set with full confidence or when experimental units are not available. In this article, we introduce and define the likelihood function of any probability distribution under the PRSS scheme. The performance of the maximum likelihood estimators is examined when the available data are assumed to have an exponentiated exponential (EE) distribution via some selective RSS schemes as well as SRS. The suggested ranked schemes include the PRSS, RSS, neoteric RSS (NRSS), and extreme RSS (ERSS). An intensive simulation study was conducted to compare and explore the behaviour of the proposed estimators. The study demonstrated that the maximum likelihood estimators via PRSS, NRSS, ERSS, and RSS schemes are more efficient than the corresponding estimators under SRS. A real data set is presented for illustrative purposes.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 37-58
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On modelling and description of the output signal of a sampling device
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2202544.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal sampling
modelling
ideal or non-ideal sampling
averaging operator
Dirac and Kronecker deltas
Opis:
The problem of an inconsistent description of an “interface” between the A/D converter and the digital signal processor that implements, for example, a digital filtering (described by a difference equation) – when a sequence of some hypothetical weighted Dirac deltas occurs at its input, instead of a sequence of numbers – is addressed in this paper. Digital signal processors work on numbers, and there is no “interface” element that converts Dirac deltas into numbers. The output of the A/D converter is directly connected to the input of the signal processor. Hence, a clear conclusion must follow that sampling devices do not generate Dirac deltas. Not the other way around. Furthermore, this fact has far-reaching implications in the spectral analysis of discrete signals, as discussed in other works referred to in this paper.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 147--155
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
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:
On the application of compressive sampling techniques to high throughput data in computational genomics
Autorzy:
Hernández-Lemus, H.
Powiązania:
https://bibliotekanauki.pl/articles/375726.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
compressive sampling
compressed sensing
computational genomics
Opis:
With the advent of high throughput experiments in genomics and proteomics, the researcher in computational data analysis is faced with new challenges, both with regards to the computational capacities and also in the probabilistic/statistical methodology fields; in order to handle such massive amounts of data in a systematic coherent way. In this paper we describe the basic aspects of the mathematical theory and the computational implications of a recently developed technique called Compressive Sampling, as well as some possible applications within the scope of Computational Genomics, and Computational Biology in general. The central idea behind this work is that most of the information sampled from the experiments turns out to be discarded (for being non-useful) in the final stages of biological analysis, hence it would be better if we could find an algorithm to remove selectively such information in order to get rid of the computational burden associated with processing and analyzing such huge amounts of data. Here we show that a possible algorithm for doing so it is precisely Compressive Sampling. As a working example, we will consider the data-analysis of whole-genome microarray gene expression for 1191 individuals within a breast cancer project.
Źródło:
Theoretical and Applied Informatics; 2011, 23, 3-4; 177-192
1896-5334
Pojawia się w:
Theoretical and Applied Informatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surveying Child Labour Through Households: Sampling Issues and Strategies
Autorzy:
Verma, Vijay
Gagliardi, Francesca
Powiązania:
https://bibliotekanauki.pl/articles/465721.pdf
Data publikacji:
2010
Wydawca:
Główny Urząd Statystyczny
Tematy:
child labour
household surveys
sampling
ILO
Opis:
This paper addresses sampling issues arising in the context of household-based child labour surveys. It presents some of the sampling strategies elaborated in the ILO book Sampling for Household-based Surveys of Child Labour (Verma, 2008). A typology of surveys of child labour is identified, and the fundamental distinction between two types with very different objectives - termed 'child labour surveys' and 'labouring children surveys', respectively - is clarified and emphasised. Following a broad survey of national practices in conducting surveys of child labour, linkages between different types of surveys and some specific sampling techniques are explained.
Źródło:
Statistics in Transition new series; 2010, 11, 3; 6-37
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physical and mechanical properties of the black turnip root flesh
Autorzy:
Starek, A.
Kusińska, E.
Guz, T.
Powiązania:
https://bibliotekanauki.pl/articles/410690.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
black turnip
physical properties
sampling site
Opis:
The paper presents the results of measurement of the basic physical properties of black turnip and the results of studies on the impact of sampling site on the textural properties of its pulp. Selected texture indices, i.e. hardness, elasticity, cohesiveness and chewiness, were determined using the TPA double compression test. The tests were carried out on samples taken from well-defined root layers (upper layer, middle layer, lower layer) and zones (A, B, C) of black turnip, because of its structural heterogeneity. The samples were compressed at the longitudinal and transverse direction of the fibers relative to the compressing device movement. The results obtained were statistically analyzed using the Statistica 10.0 program. The research has shown that the site of sampling and the direction of fiber positioning have a significant impact on the value of all the black turnip texture parameters.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2018, 7, 1; 127-136
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Categorisation Method Using Long-term Measurements
Autorzy:
Rey Gozalo, G.
Barrigón Morillas, J. M.
Gómez Escobar, V.
Vílchez-Gómez, R.
Méndez Sierra, J. A.
Carmona del Río, F. J.
Prieto Gajardo, C.
Powiązania:
https://bibliotekanauki.pl/articles/177690.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise pollution
sampling methods
street categorisation
Opis:
Previous studies concerning the categorisation method have been based on short daytime measure- ments. These studies demonstrated urban-noise stratification in the daytime. Nevertheless, legislation and standards refer to noise estimation throughout the day. This paper presents the first attempt to apply the categorisation method to indicators obtained through long-term measurements. The study was conducted in Plasencia, Extremadura (Spain) which has approximately 41,500 inhabitants. First, we conducted a stratification of the roads using the categorisation method. Second, long-term measurements (approxi- mately one week) were conducted at different sampling locations across different categories of streets. The results were analysed by category. Moreover, the profile of the noise-level variation was analysed during the day. The results revealed a stratification of sound levels measured across the different categories. Furthermore, we found health risks due to the noise levels in this town. Short-term measurements were also conducted to complete the categorisation method suitability analysis.
Źródło:
Archives of Acoustics; 2013, 38, 3; 397-405
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimized Driver Placement for Array-Driven Flat-Panel Loudspeakers
Autorzy:
Anderson, D. A.
Heilemann, M. C.
Bocko, M. F.
Powiązania:
https://bibliotekanauki.pl/articles/177774.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
loudspeaker
array
crossover network
spatial sampling
Opis:
The recently demonstrated ‘modal crossover network’ method for flat panel loudspeaker tuning employs an array of force drivers to selectively excite one or more panel bending modes from a spectrum of panel bending modes. A regularly spaced grid of drivers is a logical configuration for a two-dimensional driver array, and although this can be effective for exciting multiple panel modes it will not necessarily exhibit strong coupling to all of the modes within a given band of frequencies. In this paper a method is described to find optimal force driver array layouts to enable control of all the panel bending modes within a given frequency band. The optimization is carried out both for dynamic force actuators, treated as point forces, and for piezoelectric patch actuators. The optimized array layouts achieve similar maximum mode coupling efficiencies in comparison with regularly spaced driver arrays; however, in the optimized arrays all of the modes within a specified frequency band may be independently addressed, which is important for achieving a desired loudspeaker frequency response. Experiments on flat panel loudspeakers with optimized force actuator array layouts show that each of the panel modes within a selected frequency band may be addressed independently and that the inter-modal crosstalk is typically −30 dB or less with non-ideal drivers.
Źródło:
Archives of Acoustics; 2017, 42, 1; 93-104
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectrum Aliasing Does Occur Only in Case of Non-ideal Signal Sampling
Autorzy:
Borys, Andrzej Marek
Powiązania:
https://bibliotekanauki.pl/articles/1844609.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal sampling
occurrence of spectrum aliasing and folding
signal modelling
non ideal signal sampling operation
Opis:
In this paper, it has been shown that the spectrum aliasing and folding effects occur only in the case of non-ideal signal sampling. When the duration of the signal sampling is equal to zero, these effects do not occur at all. In other words, the absolutely necessary condition for their occurrence is just a nonzero value of this time. Periodicity of the sampling process plays a secondary role.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 1; 79-85
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Rotation Methods in Sample Surveys in Poland
Autorzy:
Kordos, Jan
Powiązania:
https://bibliotekanauki.pl/articles/466006.pdf
Data publikacji:
2012
Wydawca:
Główny Urząd Statystyczny
Tematy:
Rotation sampling
sampling on successive occasions survey across time
panel survey
data quality
sample survey
Opis:
The author reviews theory and application of rotation methods in sample surveys in Poland. He begins with reviewing designs of the surveys across time, depending on different objectives, focusing on partial rotation of sub-samples, and considers estimation problems and data quality issues generally. Next, he refers to some articles and books about surveys published over time, starting with Wilks (1940), Patterson (1950), Eckler (1955), Woodruff (1963), Rao and Graham (1964), Bailar (1975), Duncan and Kalton (1987) and Kalton and Citro (1993). He mentions also early Polish papers on rotation methods (Kordos (1966, 1967, 1971, 1982); Lednicki, 1982; Szarkowski and Witkowski, 1994), and concentrates on Polish household surveys, mainly Household Budget Survey (HBS), Labour Force Survey (LFS) and EU Statistics on Living Conditions and Income (EU-SILC). Special attention is devoted to last research on rotation sampling done by Polish sampling statisticians: Ciepiela et al. (2012), Kordos (2002), Kowalczyk (2002, 2003, 2004), Kowalski (2006, 2009), Kowalski and Wesołowski (2012) and Wesołowski (2010). Concluding remarks are given at the end.
Źródło:
Statistics in Transition new series; 2012, 13, 2; 243-260
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Probabilistyczny model wyniku pomiaru wartości chwilowej wielkości zmiennej w czasie
Probabilistic model of instantaneous value measurement result of varying in time quantity
Autorzy:
Jakubiec, J.
Powiązania:
https://bibliotekanauki.pl/articles/156154.pdf
Data publikacji:
2005
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sampling
quantizing
probabilistic error model
uncertainty
Opis:
W artykule rozpatrywane jest zagadnienie pomiaru wartości chwilowej wielkości zmieniającej się w czasie za pomocą toru pomiarowego składającego się z układu próbkująco/pamietającego oraz przetwornika A/C. Opisano sposób modelowania właściwości metrologicznych elementów toru oraz probabilistyczny model wyniku pomiaru uzyskiwanego na jego wyjściu. Przedstawiono metodę weryfikacji tego rodzaju modelu dla przypadku, gdy obejmuje on wiele źródeł błędu.
The paper characterizes the problem of instantaneous value measurement of a quantity varying in time by using a measuring chain consists of a Sample/Hold circuit and an AD converter. A method of metrological properties modeling of the chain elements and a model of measurement result obtained at the output of the chain has been presented. A verification method of such a kind model, for the situation when it contains many error sources, has been described.
Źródło:
Pomiary Automatyka Kontrola; 2005, R. 51, nr 2, 2; 28-31
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The variability of mechanical properties of the kohlrabi stalk parenchyma
Autorzy:
Starek, A.
Kusińska, E.
Powiązania:
https://bibliotekanauki.pl/articles/410825.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
kohlrabi
mechanical properties
place of sampling
Opis:
The paper presents the results of the impact of kohlrabi parenchyma sampling site on textural properties. Selected texture parameters, i.e. hardness, springinees, cohesiveness and chewiness were determined by the double compression test TPA. The study was conducted on samples taken from well-defined kohlrabi layers (upper layer, middle layer, lower layer) and zones (A, B, C), because the vegetable's structure is heterogeneous. The samples were compressedat the longitudinal and transverse orientation of the fibers relative to the movement of the working tool. The results were statistically analyzed using the program Statistica 8.0. The research has shown that the place of sampling and orientation of the fibers have a significant impact on the value of all the kohlrabi texture parameters.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 3; 9-18
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sample size in multilevel structural equation modeling – the Monte Carlo approach
Autorzy:
Sagan, Adam
Powiązania:
https://bibliotekanauki.pl/articles/424921.pdf
Data publikacji:
2019
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
sampling
multilevel SEM
Monte Carlo simulations
Opis:
In the process of sample selection, an important issue is the relationship between sample size and the type and complexity of the statistical model, which is the basis for testing research hypotheses. The paper presents methodological aspects of sample size determination in multilevel structural equation modelling (SEM) in the analysis of satisfaction with the banking products in Poland. The multilevel SEM results from the necessity to take into account both the sample size at the level of individual respondents, as well as at the higher level of analysis and the intraclass correlation coefficient. A comparison of factor loading bias based on the Monte Carlo simulation is made for different cluster sizes and the number of clusters.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2019, 23, 4; 63-79
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Two-phase Sampling Strategy for Estimating Multiple Mean Values in the Presence of Nonresponse
Strategia losowania dwufazowego dla estymacji wartości przeciętnej wielu cech w obecności braków odpowiedzi
Autorzy:
Gamrot, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/904925.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
nonresponse
callbacks
subsampling
two-phase sampling
Opis:
The phenomenon of nonresponse in sample surveys usually results in biased estimates of population characteristics. One of the means to deal with nonresponse is the subsampling technique. It relies on re-contacting some subset of nonrespondents by using more expensive and more efficient tools (e.g. direct interview) than those used in the first attempt to collect data. This allows to increase response rate and to obtain unbiased estimates of population characteristics. In this paper, the problem of establishing the sample and subsample sizes minimizing the expected cost of the survey, while achieving desired precision of multiple mean value estimates, is considered. An algorithm is proposed that allows to establish the optimum initial sample and subsample sizes for two-phase sampling strategy.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2004, 175
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Useful Results Related with Sampling Theorem and Reconstruction Formula
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/963792.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sampling theorem
cardinal series
reconstruction formula
Opis:
In this paper, we present some useful results related with the sampling theorem and the reconstruction formula. The first of them regards a relation existing between bandwidths of interpolating functions different from a perfectreconstruction one and the bandwidth of the latter. Furthermore, we prove here that two non-identical interpolating functions can have the same bandwidths if and only if their (same) bandwidth is a multiple of the bandwidth of an original unsampled signal. The next result shows that sets of sampling points of two nonidentical (but not necessarily interpolating) functions possessing different bandwidths are unique for all sampling periods smaller or equal to a given period (calculated in a theorem provided). These results are completed by the following one: in case of two different signals possessing the same bandwidth but different spectra shapes, their sets of sampling points must differ from each other.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 3; 471-475
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Topological Aspects of Sampling Theorem and Reconstruction Formula
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/226041.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
topological issues
reconstruction formula
sampling theorem
Opis:
We present here a few thoughts regarding topological aspects of transferring a signal of a continuous time into its discrete counterpart and recovering an analog signal from its discrete-time equivalent. In our view, the observations presented here highlight the essence of the above transformations. Moreover, they enable deeper understanding of the reconstruction formula and of the sampling theorem. We also interpret here these two borderline cases that are associated with a time quantization step going to zero, on the one hand, and approaching its greatest value provided by the sampling theorem, on the other.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 301-307
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using a particular sampling method for impedance measurement
Autorzy:
Lentka, G.
Powiązania:
https://bibliotekanauki.pl/articles/221836.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
impedance measurement
impedance analyzer
particular sampling
Opis:
The paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was then practically verified in a constructed simple impedance measurement instrument based on a PSoC (Programmable System on Chip). The obtained calculation simplification recommends the method for implementation in simple portable impedance analyzers destined for operation in the field or embedding in sensors.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 497-508
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analizy PVT jako skuteczne narzędzie w rękach inżyniera naftowego. Pobór wgłębnych próbek płynów złożowych do badań PVT
PVT analyses as an effective tool in the hands of the petroleum engineer. Downhole reservoir fluid sampling for PVT analysis
Autorzy:
Warnecki, Marcin
Wojnicki, Mirosław
Kuśnierczyk, Jerzy
Szuflita, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1833918.pdf
Data publikacji:
2020
Wydawca:
Instytut Nafty i Gazu - Państwowy Instytut Badawczy
Tematy:
PVT
pobór wgłębny
zmiany fazowe
wgłębny pobór płynów złożowych
downhole sampling
phase behavior
reservoir fluid sampling
Opis:
The most important aspect of laboratory analysis is undoubtedly to acquire data of the highest quality. The worldwide trend of drilling into deeper reservoirs characterised by the high temperature and high pressure (HTHP) conditions makes the newly discovered reservoirs challenging because of bearing fluids with an unprecedented diversity of phase behaviour and variability of phase parameters over time. Due to the high temperature of the deep horizons constituting the reservoir rock, many individual components of the reservoir fluids are located in a region close to their critical temperatures, i.e. gas condensate (retrograde condensation region) or volatile oil. In particular, gas condensate reservoirs are challenging to analyse. They are highly prone to the errors resulting from phase behaviour testing when using samples that are incompatible with the original reservoir in-situ fluid that saturates the reservoir rock pores. Taking the representative samples of reservoir fluid is an essential requirement to obtain reliable data that can characterise such phase-variable multicomponent reservoirs. The primary purpose of hydrocarbon fluid analysis in case of new discoveries is to determine the type of reservoir fluid system. It should also be borne in mind that without a sufficiently long production process from several intervals and/or several wells, it can be challenging to classify the fluid with confidence, especially at the initial analysis stage. The paper presents issues related to sampling of the reservoir fluid (such as crude oil and natural gas) for the physical property and phase behaviour analyses (PVT), usually accompanied by chemical analyses. The importance of representativeness of the samples in performing reliable tests that have a significant impact on the hydrocarbon production was discussed. The data obtained from the PVT laboratory are widely used in economic reports concerning local, regional or finally national hydrocarbon reserves. Other applications of the PVT data include coordination of reservoir exploitation methods related to a particular fluid composition, as well as input to design requirements for the surface facilities development, and selection of the suitable technology for hydrocarbon fluid treatment prior to introduction to the market. Various techniques of downhole sampling were mentioned and characterised with an explanation of their applicability. The criteria for selection of a proper method were also presented.
Źródło:
Nafta-Gaz; 2020, 76, 11; 784--793
0867-8871
Pojawia się w:
Nafta-Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved Estimators for Simple Random Sampling and Stratified Random Sampling under Second Order of Approximation
Autorzy:
Sharma, Prayas
Powiązania:
https://bibliotekanauki.pl/articles/465938.pdf
Data publikacji:
2014
Wydawca:
Główny Urząd Statystyczny
Tematy:
simple random sampling
stratified random sampling population mean
study variable
exponential ratio type estimators
bias and MSE
Opis:
Singh and Solanki (2012) and Koyuncu (2012) proposed estimators for estimating population meanY. Up to the first order of approximation and under optimum conditions, the minimum mean squared error of both the estimators is equal to the MSE of the regression estimator. In this paper, we have tried to find out the second order biases and mean square errors of these estimators using information on auxiliary variable based on simple random sampling. Finally, we have compared the performance of these estimators with some numerical illustration.
Źródło:
Statistics in Transition new series; 2014, 15, 3; 379-390
1234-7655
Pojawia się w:
Statistics in Transition new series
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:
Modelling of non-ideal signal sampling via averaging operation and spectrum of sampled signal predicted by this model
Autorzy:
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/2172501.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
modelling of non-Ideal signal sampling
non-Ideal signal
spectrum of sampled signal
A/D converters
non-Ideal signal sampling
signal sampling
discrete time fourier transform
Opis:
In this paper, a novel model of a non-ideal signal sampling via a local, periodic averaging operation is present-ed. The spectrum of a sampled signal predicted by this model is also analysed as well as compared with a one following from another model.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 2; 274--278
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ensuring the reliability and reduction of quality control costs by minimizing process variability
Autorzy:
Rogalewicz, Michał
Kujawińska, Agnieszka
Feledziak, Adrianna
Powiązania:
https://bibliotekanauki.pl/articles/24200827.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
quality inspection
reliability
quality cost
sampling inspection
Opis:
This paper presents a method for planning the range of quality control while ensuring its reliability and minimizing costs. The method is dedicated to destructive inspection, in which the cost of performing the measurement is significant in relation to the cost of manufacturing a part or product. The methodology was divided into four main stages: (1) selection of the measurement system and definition of the inspection scope and sample size, (2) process control, (3) redefining the scope of control and (4) verification of control cost and reliability after sample size change. The article presents the results of applying the author's procedure to the process of evaluating seat belts in automotive industry. Belts are used in the process of controlling the final product, which is a seat belt anchor plate. This approach allowed to reduce the number of destroyed parts during control while maintaining the credibility of the decision based on the assessment. As a result of double-decreasing the sample size, the costs of seat belt quality control were reduced. Assuming an average of 40 seat belt deliveries per year, the material cost was reduced by 50%. Limiting the sample size to 15 pieces per delivery would reduce the cost of testing from by 45%. It was achieved maintaining the appropriate level of credibility of decisions made greater than 0.8.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 2; art. no. 162626
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Measurement Error Using Local Sampling and Joint Nonparametric Linearisation
Estymowanie błędu pomiarowego z zastosowaniem łącznej nieparametrycznej linearyzacji prób lokalnych
Autorzy:
Górkiewicz, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/906540.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
local sampling
linearisation
measurement error
neear neighbours
Opis:
This paper presents how to use the near neighbours technique in aim to transform a given data set (Z, X, YT) of size N into a set of J ~ N local samples (Z, X), with restrictions on minimal number К of members in each local sample and on maximal difference of Y inside each local sample, where Z plays role of an outcome, X is an independent variable, and Y1 - (Y ..., YL) is a vector of L supplementary continuous variables. Then the procedure for non-parametric joint linearisation of an obtained set of local samples was proposed. The whole proposed method was applied to estimation of models with standard deviation of measurements as outcome Z and measured value as independent variable X. The paper was inspired by difficulties with estimation of the measurement error, which often occur in medicine, if accuracy of a measurement procedure depends on some properties of patient. Nevertheless, the proposed approach seems to be more general. It can be useful in many analyses of observational studies, which aim to estimate a family of the functions, preferable the linear ones, instead a single multivariate model.
Praca prezentuje zastosowanie techniki najbliższych sąsiadów w celu przekształcenia zbioru N danych postaci (Z, X, YT) w zbiór J ~ N prób lokalnych (Z, X), przy ograniczeniach dotyczących minimalnej liczby danych К oraz różnic wartości YT w każdej próbie lokalnej, gdzie Z pełni rolę zmiennej zależnej, X - zmiennej niezależnej, a Y1 = (Y, ..., YL) jest L-wymiarową zmienną dodatkową. Następnie proponuje się procedurę nieparametrycznej łącznej linearyzacji zbioru prób lokalnych. Obie procedury proponuje się stosować do oceny dokładności metod pomiarowych, z odchyleniem standardowym błędu pomiarów jako zmienną Z i wielkością mierzoną jako zmienną X. Proponowane podejście może być użyteczne w innych zastosowaniach, kiedy zamiast modelu regresji wielowymiarowej estymuje się rodzinę zależności regresyjnych.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2002, 162
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
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:
Rola statystyki w życiu społeczeństwa i funkcjonowaniu państwa
The role of statistics for society and the functioning of the state
Autorzy:
Iwasiewicz, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/528349.pdf
Data publikacji:
2011
Wydawca:
Krakowska Akademia im. Andrzeja Frycza Modrzewskiego
Tematy:
statistics
survey sampling
sampling techniques
sampling methods
advetising research
consumer price index (CPI)
producer price index (PPI)
demography
statystyka
badania sondażowe
metoda reprezentacyjna
wskaźniki inflacji (CPI, PPI)
demografia
Źródło:
Państwo i Społeczeństwo; 2011, 2; 105-132
1643-8299
2451-0858
Pojawia się w:
Państwo i Społeczeństwo
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

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