Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Statistics" wg kryterium: Temat


Tytuł:
Statistical approach for the estimation of watershed scale nitrate export : a case study from Melen watershed of Turkey
Autorzy:
Akiner, M. E.
Akkoyunlu, A.
Powiązania:
https://bibliotekanauki.pl/articles/205066.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pollution
river
water quality
retention coefficient
nitrate export coefficients
Frequentist statistics
Bayesian statistics
Opis:
Nutrient pollution such as nitrate (NO3−) can cause water quality degradation in rivers used as a source of drinking water. This situation raises the question of how the nutrients have moved depending on many factors such as land use and anthropogenic sources. Researchers developed several nutrient export coefficient models depending on the aforementioned factors. To this purpose, statistical data including a number of factors such as historical water quality and land use data for the Melen Watershed were used. Nitrate export coefficients are estimates of the total load or mass of nitrate (NO3−) exported from a watershed standardized to unit area and unit time (e.g. kg/km2/day). In this study, nitrate export coefficients for the Melen Watershed were determined using the model that covers the Frequentist and Bayesian approaches. River retention coefficient was determined and introduced into the model as an important variable.
Źródło:
Archives of Environmental Protection; 2016, 42, 2; 44-51
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forecasting the distribution of precipitate diameters in the presence of changes in the structure of the material
Autorzy:
Zieliński, A.
Miczka, M.
Golański, G.
Powiązania:
https://bibliotekanauki.pl/articles/356680.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microstructure
precipitates
statistics
forecasting
ageing
Opis:
The results of investigations on the microstructure of T23 and T24 low-alloy steels as well as P91 and P92 high-chromium steels in the as-received condition and after 70.000 h annealing at 550-650°C are presented. The quantitative analysis of the existing precipitates was performed for representative images of microstructure. The statistical analysis of collected data allowed the parameters of a selected theoretical statistical distribution to be estimated. A forecast of average precipitate diameter and standard deviation of such a distribution for the time of 100,000 hours at 550 and 600°C for T23 and T24 steels and at 600 and 650°C for P91 and P92 steels was calculated. The obtained results of investigations have made it possible to compare changes in the microstructure of various steel grades due to long-term impact of elevated temperature. They have also confirmed the possibility of using, in evaluating the degradation degree of materials in use, the forecasting methods that derive from mathematical statistics, in particular the theory of stochastic processes and forecast by analogy methods. The presented approach allows the development of a forecast of precipitate diameter probability density under the microstructure instability conditions for selected steel grades. The assessment of material condition that takes into consideration, but is not limited to, the precipitate diameter measurement is useful as an assessment component in estimating the time of safe service of power unit elements working under creep conditions.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 273-280
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Forecasting the Particle Diameter Size Distribution in P92 (X10CrWMoVNb9-2) Steel After Long-Term Ageing at 600 and 650°C
Autorzy:
Zieliński, A.
Sroka, M.
Miczka, M.
Śliwa, A.
Powiązania:
https://bibliotekanauki.pl/articles/355265.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
P92 steel
microstructure
precipitates
statistics
forecasting
Opis:
The investigations on microstructure of P92 steel in the as-received condition and after 105h ageing at 600 and 650°C were carried out. For the recorded images of microstructure, the quantitative analysis of precipitates was performed. On that basis, a statistical analysis of collected data was made with the aim of estimating parameters of selected theoretical statistical distribution. Then, the forecast for average precipitate diameter and standard deviation of such a distribution for the time of 1,5*105h at 600 and 650°C was calculated. The obtained results of investigations confirm the possibility of using, in evaluation of degradation degree for materials in use, the forecasting methods derived from mathematical statistics, in particular the theory of stochastic processes and methods of forecasting by analogy.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 753-760
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bezład przestrzenny a zasoby informacji o stanie planowania przestrzennego w Polsce
Autorzy:
Pieniążek, Marek
Orleański, Michał
Powiązania:
https://bibliotekanauki.pl/articles/2025061.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
monitoring
regional statistics
spatial disorder
spatial planning
Źródło:
Studia komitetu przestrzennego zagospodarowania kraju PAN; 2018, 182, 2; 425-430
0079-3507
Pojawia się w:
Studia komitetu przestrzennego zagospodarowania kraju PAN
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distinguishing between two Antarctic species of Eocene Palaeeudyptes penguins: a statistical approach using tarsometatarsi
Autorzy:
Jadwiszczak, Piotr
Hospitaleche, Carolina Acosta
Powiązania:
https://bibliotekanauki.pl/articles/2051388.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Antarctic
La Meseta Formation
Paleogene
Sphenisciformes
statistics
systematics
Źródło:
Polish Polar Research; 2013, 3; 237-252
0138-0338
2081-8262
Pojawia się w:
Polish Polar Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Echosignal Applied to Human Skin Lesions Characterization
Autorzy:
Piotrzkowska, H.
Litniewski, J.
Szymańska, E.
Nowicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/177296.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
statistics
K-distribution
Rayleigh distribution
ultrasonic scattering
human dermis
Opis:
The paper presents a classification of the healthy skin and the skin lesions (basal cell carcinoma) basing on a statistics of the envelope of ultrasonic echoes. The echoes envelopes distributions were modeled using Rayleigh and K-distribution. The distributions were compared with empirical data to find which of them better models the statistics of the echo-signal obtained from the human skin. The results indicated that the K-distribution provides a better fit. Also, a characteristic parameter of the K-distribution, the effective number of scatterers (M), was investigated. The values of the M parameter, obtained for the skin cancer (basal cell carcinoma), were lower as compared to those obtained for the healthy skin. The results indicate that the statistical quan- titative ultrasound parameters have a potential for extracting information useful for characterization of the skin condition.
Źródło:
Archives of Acoustics; 2012, 37, 1; 103-108
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accuracy assessment of TanDEM-X IDEM using airborne LiDAR on the area of Poland
Autorzy:
Woroszkiewicz, M.
Ewiak, I.
Lulkowska, P.
Powiązania:
https://bibliotekanauki.pl/articles/145569.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
InSAR
Lidar
DTM
accuracy
statistics
interferometria radarowa
model powierzchniowy
lidar
Opis:
The TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) mission launched in 2010 is another programme – after the Shuttle Radar Topography Mission (SRTM) in 2000 – that uses space-borne radar interferometry to build a global digital surface model. This article presents the accuracy assessment of the TanDEM-X intermediate Digital Elevation Model (IDEM) provided by the German Aerospace Center (DLR) under the project “Accuracy assessment of a Digital Elevation Model based on TanDEM-X data” for the southwestern territory of Poland. The study area included: open terrain, urban terrain and forested terrain. Based on a set of 17,498 reference points acquired by airborne laser scanning, the mean errors of average heights and standard deviations were calculated for areas with a terrain slope below 2 degrees, between 2 and 6 degrees and above 6 degrees. The absolute accuracy of the IDEM data for the analysed area, expressed as a root mean square error (Total RMSE), was 0.77 m.
Źródło:
Geodesy and Cartography; 2017, 66, 1; 137-148
2080-6736
2300-2581
Pojawia się w:
Geodesy and Cartography
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fracture Statistics Using Three-Parameter and Two-Parameter Weibull Distributions for Fe-0.4C-1.5Cr-1.5Ni-0.8Mn-0.2Mo Structural Sintered Steel
Autorzy:
Fiał, C.
Ciaś, A.
Czarski, A.
Sułowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/353218.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sintered structural steels
mechanical properties
Weibull statistics
maximum likelihood
threshold parameter
Opis:
A statistical analysis is presented of tensile and bending strengths of a porous sintered structural steel which exhibits non-linear, quasi-brittle, behaviour. It is the result of existing natural flaws (pores and oxide inclusions) and of the formation of fresh flaws when stress is applied. The analysis is by two- and three-parameter Weibull statistics. Weibull modulus, a measure of reliability, was estimated by the maximum likelihood method for specimen populations < 30. Probability distributions were compared on the basis of goodness to fit using the Anderson-Darling tests. The use of the two-parameter Weibull distribution for strength data of quasi-brittle sintered steels is questioned, because there is sufficient evidence that the 3-parameter distribution fits the data better.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1547-1554
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Confidence Intervals for the Long-Term Noise Indicators Using the Kernel Density Estimator
Autorzy:
Stępień, B.
Powiązania:
https://bibliotekanauki.pl/articles/177575.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
long-term noise indicators
non-classical statistics
interval estimation
kernel density estimator
Opis:
A non-classical model of interval estimation based on the kernel density estimator is presented in this paper. This model has been compared with interval estimation algorithms of the classical (parametric) statistics assuming that the standard deviation of the population is either known or unknown. The non-classical model does not have to assume belonging of random sample to a normal distribution. A theoretical basis of the proposed model is presented as well as an example of calculation process which makes possible determining confidence intervals of the expected value of long-term noise indicators LDEN and LN. The statistical analysis was carried out for 95% interval widths obtained by using each of these models. The inference of their usefulness was performed on the basis of results of non-parametric statistical tests at significance level α = 0.05. The data used to illustrate the proposed solutions and carry out the analysis were results of continuous monitoring of traffic noise recorded in 2004 in one of the main arteries of Kraków in Poland.
Źródło:
Archives of Acoustics; 2016, 41, 3; 517-525
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty of the characteristics of electrical devices based on the measurements of time-current characteristics of MV fuses
Autorzy:
Daszczyński, T.
Pochanke, Z.
Kolimas, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/200192.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
time-current characteristic
MV fuse
approximation of measurement results
fuse element
statistics
Opis:
Functional properties of some electrical devices are expressed in the form of a dependence between parameters defining a given aspect of device duty or work circumstance (e.g. breakdown voltage): contacts distance for a circuit breaker, current (voltage for voltage limiters or reaction time), and load current for over current protection. Such characteristics are obtained experimentally, usually in a set of test series, each performed with a fixed independent parameter. Results of each series generate sets of data for estimation of statistical properties of a dependent parameter: distribution, expected value, variance and confidence interval. These statistics concern one point of the tested characteristic, so to get data of it as a whole, that would satisfy the needs for designing an electrical system, a large number of tests can be necessary. The way to reduce the number of tests may consists in: defining the characteristic not as a series of points, but as an analytical function with some specific parameters. This can be combined with aggregation of results of all tests in one set of data for estimation of statistical properties of the mantioned parameter. This paper presents an application of the above approach to tests of time-current characteristics of fuses.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 751-757
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Real-time parameter estimation study for inertia properties of ground vehicles
Metody estymacji parametrów w czasie rzeczywistym dla wyznaczania właściwości inercyjnych pojazdu terenowego
Autorzy:
Kolansky, J.
Sandu, C.
Powiązania:
https://bibliotekanauki.pl/articles/139960.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
parameter estimation
EKF
polynomial chaos
bayesian statistics
estymacja parametrów
chaos wielomianowy
statystyka bayesowska
Opis:
Vehicle parameters have a significant impact on handling, stability, and rollover propensity. This study demonstrates two methods that estimate the inertia values of a ground vehicle in real-time. Through the use of the Generalized Polynomial Chaos (gPC) technique for propagating the uncertainties, the uncertain vehicle model outputs a probability density function for each of the variables. These probability density functions (PDFs) can be used to estimate the values of the parameters through several statistical methods. The method used here is the Maximum A-Posteriori (MAP) estimate. The MAP estimate maximizes the distribution of P(β ׀z) where β is the vector of the PDFs of the parameters and z is the measurable sensor comparison. An alternative method is the application of an adaptive filtering method. The Kalman Filter is an example of an adaptive filter. This method, when blended with the gPC theory is capable at each time step of updating the PDFs of the parameter distributions. These PDF’s have their median values shifted by the filter to approximate the actual values.
Parametry pojazdu mają znaczny wpływ na jego właściwości, takie jak sterowalność, stabilność i odporność na wywrócenie. W pracy przedstawiono dwie metody estymacji parametrów inercyjnych pojazdu terenowego w czasie rzeczywistym. W modelu pojazdu z niepewnościami wyznacza się funkcje gęstości prawdopodobieństwa (PDF) dla każdej wielkości opisując propagację niepewności przez zastosowanie techniki uogólnionego chaosu wielomianowego (gPC). Funkcje te mogą być użyte do estymacji wartości parametrów przy wykorzystaniu różnych metod statystycznych. W pracy zastosowano metodę maksymalnego estymatora a posteriori (MAP). Estymator MAP maksymalizuje funkcję rozkładu P(β ׀z), gdzie β jest wektorem funkcji gęstości prawdopodobieństwa parametrów, a z jest wielkością mierzalną, otrzymaną z porównania wyjść czujników. Metodą alternatywną jest zastosowanie filtru adaptacyjnego, którego przykładem jest filtr Kalmana. Metoda ta, w połączeniu z techniką uogólnionego chaosu wielomianowego (gPC), umożliwia, w każdym kroku adaptacji, uaktualnianie funkcji gęstości prawdopodobieństwa (PDF) parametrów systemu. Działanie filtru powoduje, że mediany tych funkcji zmieniają się dążąc do rzeczywistych wartości poszukiwanych parametrów.
Źródło:
Archive of Mechanical Engineering; 2013, LX, 1; 7-21
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oszacowanie rzeczywistej liczby ludności gmin województwa mazowieckiego z wykorzystaniem danych ZUS
Estimation of the actual population of communes in the Mazovia voivodship using the data of the social insurance institution (ZUS)
Autorzy:
Śleszyński, Przemysław
Powiązania:
https://bibliotekanauki.pl/articles/418236.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
population statistics
population registration
the actual number of residents
population estimation
Mazovia voivodship
Opis:
The article presents the problem of lack of compliance with population registration requirements, in relation to the factual place of residence. This problem persists in Poland due to the reliance of official statistics on the data on current registrations, and also due to adoption of the legal, rather than factual definition of residence. To estimate the extent of this phenomenon for Mazovia voivodship, the data of the Social Insurance Institution (ZUS) are used, which enable a comparison of the addresses of permanent residence with the address for correspondence of the insured persons. Depending on the age group, the identified differences were quite high, especially for the most mobile ages (e.g. over 9% for people aged 27 years). Spatial concentration was also shown, especially with respect to underestimation of the true population of Warsaw and its suburban areas, and overestimation for peripheral regions. In many communes the problem of non-compliance with registration requirements concerns over 10% of the registered population. This limits the scope of demographic analyses, especially in the context of their practical applications and population projections
Źródło:
Studia Demograficzne; 2011, 2(160); 35-58
0039-3134
Pojawia się w:
Studia Demograficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Being more idiographic in the nomothetic world
Autorzy:
Korulczyk, Tomasz
Biela, Adam
Blampied, Neville
Powiązania:
https://bibliotekanauki.pl/articles/2129704.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
longitudinal research
Modified Brinley Plot
Reliable Change Index
idiographic approach
IBM SPSS Statistics
Opis:
Since psychology emerged as an independent field of knowledge, there has been no consensus as to how it should develop, either, in the idiographic or nomothetic way. In the course of time, due to a commitment to what was seen as objectivity in science, the nomothetic approach came to dominate psychology. Thus, researchers used mostly quantitative psychometric methods to establish general rules of human behaviour. In doing so, the essence of nomothetic research is to be extremely careful when interpreting results not to make a reasoning mistake such as the ecological fallacy, as may happen when a researcher draws conclusions about nature of the individual in the group based on average results of the whole group. In the article, we presented two methods for longitudinal research designs which address this problem, and give more idiographic information about participants; via the Reliable Change Index and the Modified Brinley Plot. Finally, we provide a IBM SPSS Statistics syntax automatizing the whole process of computation for these new features.
Źródło:
Polish Psychological Bulletin; 2019, 50, 2; 207-216
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wyludnianie Tradycyjnych Regionów Górniczych Europy Środkowo-Wschodniej
Depopulation of Traditional Mining Regions in East-Central Europe
Autorzy:
Rechłowicz, Marcin
Tkocz, Maria
Powiązania:
https://bibliotekanauki.pl/articles/418259.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
depopulation, vital statistics
East-Central Europe
the Silesian Voivodeship
Donbas
the Ostrava agglomeration
Opis:
The phenomenon of depopulation was observed in the last two decades in regions of East-Central Europe where the economy had previously relied upon natural resource extraction throughout the socialist period. The restructuring of traditional branches of industry, such as mining and metallurgy, has had a negative impact on the demographic potential of industrial agglomerations as well as the surrounding areas. This article focuses on an analysis of population change after the year 1990 in the following affected regions: Silesian Voivodeship in Poland, Moravian-Silesian in the Czech Republic, and Donetsk Oblast and Luhansk Oblast in Ukraine. It also defines the types of demographic change and explains causal factors of observed processes. The population of regions mentioned above decreased from 14,4 to 12,6 million people in the period under consideration. The largest population decline was observed in Luhansk Oblast (-20,0 %) and Donetsk Oblast (-16,9 %). A considerably lower decline took place in Silesian Voivodeship (-5,7 %) and in Moravian-Silesian (-3,3 %). We find that differences in the rates of population decline are derived mainly from heterogeneity in the vital statistics of those regions while migration plays a more minor role in the depopulation process.
Źródło:
Studia Demograficzne; 2012, 162, 2; 29-53
0039-3134
Pojawia się w:
Studia Demograficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Type A Standard Uncertainty of Long-Term Noise Indicators
Autorzy:
Batko, W. M.
Stępień, B.
Powiązania:
https://bibliotekanauki.pl/articles/176923.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
long-term noise indicator
uncertainty
non-classical statistics
kernel density estimation
bootstrap
Bayesian inference
Opis:
The problem of estimation of the long-term environmental noise hazard indicators and their uncer- tainty is presented in the present paper. The type A standard uncertainty is defined by the standard deviation of the mean. The rules given in the ISO/IEC Guide 98 are used in the calculations. It is usually determined by means of the classic variance estimators, under the following assumptions: the normality of measurements results, adequate sample size, lack of correlation between elements of the sample and observation equivalence. However, such assumptions in relation to the acoustic measurements are rather questionable. This is the reason why the authors indicated the necessity of implementation of non-classical statistical solutions. An estimation idea of seeking density function of long-term noise indicators distri- bution by the kernel density estimation, bootstrap method and Bayesian inference have been formulated. These methods do not generate limitations for form and properties of analyzed statistics. The theoretical basis of the proposed methods is presented in this paper as well as an example of calculation process of expected value and variance of long-term noise indicators LDEN and LN. The illustration of indicated solutions and their usefulness analysis were constant due to monitoring results of traffic noise recorded in Cracow, Poland.
Źródło:
Archives of Acoustics; 2014, 39, 1; 25-36
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies