Wyniki wyszukiwania - Biblioteka Nauki

1

Ciąg rozkładów prawdopodobieństwa i jego podstawowe własności

100%

Zapała W.

Zeszyty Naukowe. Górnictwo / Politechnika Śląska

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2005

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tom z. 269

593-603

PL

Przedstawiono ciąg rozkładów prawdopodobieństwa. Omówiono podstawowe własności tego ciągu. Wykazano, że wszystkie rozkłady prawdopodobieństwa wchodzące w skład zdefiniowanego ciągu mają taką samą wartość średnią i taką samą wariancję. Udowodniono, że zaprezentowany ciąg rozkładów prawdopodobieństwa jest zbieżny do rozkładu normalnego.

EN

The series of probability distributions has been presented in the paper. Basic properties of this series have been discussed. It has been proved that all probability distributions which constitute this defined series have the same mean value and the same variance as well as the series of probability distributions converges to Gaussian distribution.

2

Analysis of the Accuracy of Uncertainty Noise Measurement

80%

Przysucha B. , Batko W. , Szeląg A.

Archives of Acoustics

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2015

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tom Vol. 40, No. 2

183--189

EN

The paper formulates some objections to the methods of evaluation of uncertainty in noise measurement which are presented in two standards: ISO 9612 (2009) and DIN 45641 (1990). In particular, it focuses on approximation of an equivalent sound level by a function which depends on the arithmetic average of sound levels. Depending on the nature of a random sample the exact value of the equivalent sound level may be significantly different from an approximate one, which might lead to erroneous estimation of the uncertainty of noise indicators. The article presents an analysis of this problem and the adequacy of the solution depending on the type of a random sample.

3

Chain length probability distribution - equivalence of ASYNNNI and 1d Ising model

80%

Milić M.

Open Physics

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2008

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tom 6

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nr 2

311-316

EN

An expression for the chain length probability distribution p(l) of a one dimensional Ising chain was derived using the cluster variation method formalism, the p(l) being expressed through the pair cluster probabilities. It was shown numerically that the same expression also applies in the case of one dimensional chains formed along one of the next-nearest neighbor interactions included in the two dimensional ASYNNNI (Asymmetric Next-Nearest Neighbor Ising) model, widely used to describe the statistics of oxygen ordering in the basal CuOx planes of the YBa2Cu3O6+x type high-Tc superconducting materials. Equivalency between ASYNNNI and 1d Ising model is discussed.

4

Self-regulating genes. Exact steady state solution by using Poisson representation

80%

Sugár I. , Simon I.

Open Physics

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2014

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tom 12

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nr 9

615-627

EN

Systems biology studies the structure and behavior of complex gene regulatory networks. One of its aims is to develop a quantitative understanding of the modular components that constitute such networks. The self-regulating gene is a type of auto regulatory genetic modules which appears in over 40% of known transcription factors in E. coli. In this work, using the technique of Poisson Representation, we are able to provide exact steady state solutions for this feedback model. By using the methods of synthetic biology (P.E.M. Purnick and Weiss, R., Nature Reviews, Molecular Cell Biology, 2009, 10: 410–422) one can build the system itself from modules like this.

5

Estimate the probability density function of maximum temperature for the Middle East

80%

Al-Ataby I. K. , Al-Tmimi A. I.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2020

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tom Vol. 29, No. 4

517--531

EN

Pollution is one reasons for increase temperature which leads to increase the heat waves which have large socioeconomic and healthy impacts on Middle East. By using monthly daily mean of maximum temperature (C°) at height (2m) covered middle east as a grid of (1581) points for selected months (March, April, May) represent spring and (Jun, July, August) represent Summer for the period 1979 to2018, from the ECMWF, model ERA-interim. Many PDFs have been proposed in recent past, but in present study Logistic, Rayleigh and Gamma distribution are used to describe the characteristics of maximum temperature. This paper attempts to determine the best fitted probability distribution of maximum temperature. To check the accuracy of the predicted data using theoretical probability distributions the goodness of fit criteria Z-test used in this paper. According to the goodness-of-fit criteria and from the graphical comparisons it can be said that Logistic distribution provides the best fit for the observed monthly daily mean of maximum temperature data.

6

Estimate the probability density function of maximum temperature for the Middle East

80%

Al-Ataby I. K. , Al-Tmimi A. I.

Przegląd Naukowy. Inżynieria i Kształtowanie Środowiska

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2020

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tom 29

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nr 4[90]

7

On the probability distribution of Earth Orientation Parameters data

80%

Niedzielski T. , Sen A. K. , Kosek W.

Artificial Satellites : Journal of Planetary Geodesy

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2009

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tom Vol. 44, No. 1

33--41

EN

Earth Orientation Parameters (EOPs), i.e. pole coordinates (xp, yp), Universal Time (UT1-UTC), and celestial pole offsets (dX, dY ), are the transformation parameters between the International Terrestrial Reference Frame (ITRF) and the International Celestial Reference Frame (ICRF). It is customarily assumed that each of the EOP time series follows the normal distribution. The normality assumption has been used specifically in EOP prediction studies. The objective of this paper is to investigate the normality hypothesis in detail. We analysed the daily time series of xp, yp, UT1-UTC, length-of-day (Δ), dX, and dY in the time interval from 01.01.1962 to 31.12.2008. The UT1-UTC data were transformed to UT1R-TAI by removing leap seconds and the tidal signal using the IERS model. The tidal effects δΔ were also removed from the Δ time series and Δ−δΔ data were obtained. Furthermore, we constructed the residuals of these time series using least-squares fit. We evaluated the skewness and kurtosis and tested their statistical significance by the D’Agostino and the Anscombe-Glynn tests, respectively. In addition, the Anderson-Darling test for the normal distribution was applied. It was found that the xp, yp time series and their residuals slightly depart from the normal distribution, but this departure is rather due to marginal flattening/narrowing of the probability density function than due to extreme values. The UT1R-TAI time series and its residuals were also classified as non-Gaussian, however, the deviations from the normal distribution are again slight. The similar results hold for the Δ - δΔ data, but some of its residuals were found to be Gaussian. We noticed that the celestial pole offsets, dX and dY , tend to deviate from the Gaussian distribution. In addition, we examined the determination errors of EOP data and found them to depart significantly from the normal distribution.

8

A New Approach to the Maximum Quarterly Water Consumption Modeling on the Example of Individual Water Consumers in a Small Water Supply System

80%

Młyńska A. , Bergel T. , Młyński D.

Rocznik Ochrona Środowiska

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2021

|

tom Tom 23

180--197

EN

Quarterly water consumption data collected in a small water supply system were used for elaboration of a new water consumption modeling approach. In this paper, multi-distribution statistical analysis was performed. As the Anderson-Darling test proved, at least a half out of the ten tested theoretical probability distributions can be used for description of the water consumption. The application of the PWRMSE criterion made it possible to determine, which of the tested theoretical distributions is the best-fitted to the empirical data set. In the case of total daily water consumption for the group of the households, it was Johnson distribution, whereas for the average daily water consumption per capita, it was GEV distribution. Based on the best-fitted probability distribution, a 25-year water consumption simulation with the Monte Carlo method was conducted. Because methodology of this study is based on the probability distributions, even if the type of theoretical distribution of the water consumption will change, it will be still possible to use this simulation method by assuming the other distribution.

9

The probabilistic model of fatigue life estimation for structural elements with heterogeneous stress distribution

71%

Karolczuk A. , Karolczuk A.

|

nr 3

10

Reliability enhancement using optimization analysis

70%

Madlenak R. , Dutkova S. , Hostakova D. , Sarkan B.

Zeszyty Naukowe. Transport / Politechnika Śląska

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2018

|

tom z. 100

115--125

EN

This paper presents an optimization analysis of a queuing system for a particular post office as a tool to increase system reliability. The consideration of system reliability in terms of queuing system failures is very relevant. One way to increase reliability is to analyse the system and its parameters in order to identify its most critical flaws. We used the chi-squared goodness-of-fit test based on the validation of a null hypothesis over an alternative hypothesis. The purpose of the test was to verify the correspondence of the measured data with a theoretical probability distribution. Measurements of relevant data were performed on the specific post office that represented the subject of our research. This approach proved to be a powerful tool in system analysis and optimization. The results of such an analysis can serve as the basis for the modelling of queuing systems.

11

Analysis of the Accuracy of Uncertainty Noise Measurement

70%

Przysucha B. , Batko W. , Szeląg A.

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tom 40

|

nr 2

12

Drawing the optimal depth-age curve on the basis of calibrated radiocarbon dates

70%

Walanus A.

Geochronometria

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2008

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tom Vol. 31

1-5

EN

The radiocarbon determination of age has the form of a complicated probability density function. In some cases however it is possible to exploit it in a precise way, in drawing the depth-age curve when a stratigraphic sequence of 14C ages is available. It is also possible to use this function in drawing the depth-age curve by hand. The necessary additional constraint on the depth-age curve adopted here is the simplicity of its shape, namely the low curvature.

13

Assessment of the reliability of the operation of a sewage treatment plant using Monte Carlo simulation

60%

Migdał K. , Operacz A. , Vaskina I. , Śliz P. , Tavares J. , Almeida A. , Migdał M.

Journal of Water and Land Development

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2022

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tom Special Issue

80--90

EN

The aim of the study was to model the operation of a wastewater treatment plant using the Monte Carlo method and selected probability distributions of random variables. Pollutant indices in treated wastewater were analysed, such as: biological oxygen demand (BOD5), chemical oxygen demand (CODCr), total suspended solids (TSS), total nitrogen (Ntot), total phosphorus (Ptot). The preliminary analysis of pollution indicators series included the: calculation of descriptive statistics and assessment of biological degradability of wastewater. The consistency of the theoretical distributions with the empirical ones was assessed using Anderson-Darling statistics. The best-fitting statistical distributions were selected using the percent bias criterion. Based on the calculations performed, it was found that the analysed indicators of pollution in treated wastewater were characterised by an average variability of composition for BOD5, CODCr and TSS, and a high variability of composition for Ntot and Ptot. The best fitted distribution was log-normal for BOD5, TSS, Ntot and Ptot and general extreme values for CODCr. The simulation carried out using the Monte-Carlo method confirmed that there may be problems associated with the reduction of nutrients (Ntot and Ptot) the analysed wastewater treatment plant. Results of values obtained of the risk values of negative control of wastewater treatment plant operation for biogenic compounds, different from 1, indicate that the number of exceedances at the outflow may be higher than the acceptable one.

14

Badanie zmienności postępu eksploatacji przodków ścianowych na przykładzie wybranej kopalni węgla kamiennego

60%

Franik T. , Woźny T.

Przegląd Górniczy

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2011

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tom T. 67, nr 9

40--45

PL

W pracy przedstawiono analizę dynamiki zmian postępu eksploatacji przodków ścianowych, wyposażonych w wysoko wydajny sprzęt w wybranej kopalni węgla kamiennego. Badania obejmowały 16 przodków ścianowych eksploatowanych w latach 2006÷2010. Zmienność postępu a zatem także efektów produkcyjnych osiąganych w poszczególnych przodkach ścianowych, jest wynikiem skumulowanego oddziaływania wielu czynników. Okoliczność ta była powodem potraktowania postępu eksploatacji jako zmiennej losowej, której rozkłady badano z użyciem pakietu Statistica. Charakter rozkładu postępu eksploatacji ściany oraz przewidywane prawdopodobieństwo wystąpienia określonej jego wielkości są istotnymi informacjami dla projektowania przyszłej eksploatacji pól ścianowych w określonych warunkach geologiczno-górniczych i technicznych.

EN

The dissertation reveals the analysis of the dynamics of changes of exploitation advance of longwall faces, fitted out with highly efficient equipment in a selected hard coal mine. The examinations comprised 16 longwall faces extracted in the years 2006÷2010. The changeability of advance and thus the production effects attained at individual longwall faces is the result of cumulative influence of numerous factors. This circumstance was the reason for treating longwall extraction advance as a random variable; its distributions were examined using the Statistics package. The character of distribution of the longwall extraction advance as well as the predicted probability of occurrence of its determined size are essential information for planning future extraction of longwall panels in specific geological-and-mining and technical conditions.

15

Multiple co-channel interferers influence on the selection diversity system over Rayleigh fading channels

60%

Stefanović H. , Petrović I. , Stefanović M. , Panić S. , Spalević P.

Przegląd Elektrotechniczny

|

2012

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tom R. 88, nr 1a

222-224

EN

Selection combining (SC) diversity receiver experiencing an arbitrary number of multiple, independent, equal power co-channel interferers, in the presence of Rayleigh fading channels was analyzed. Closed form expressions are obtained for the output SIR’s probability density function (PDF) and cumulative distribution function (CDF). In order to show the effects of the number of multiple interferers, diversity order and input SIR unbalance to the system performances, an outage probability (OP) analysis is derived. Another important measure of the system’s performances, an average bit error probability (ABER) is efficiently evaluated for non-coherent modulation schemes such as binary frequency-shift keying (BFSK) and binary differentially phase-shift keying (BDPSK).

PL

Przeanalizowano wpływ interferencji między wieloma niezależnymi kanałami (w obecności kanału Rayleigha z zanikami) na wybór najlepszego sygnału. Przedstawiono wyrażenie na prawdopodobieństwo parametru SIR (signal to interference ratio) oraz średnie prawdopodobieństwo bitu błędu (ABER).

16

Metoda alternatywy zdarzeń identyfikacji rozkładu prawdopodobieństwa przepływów maksymalnych w roku : analiza krytyczna

60%

Węglarczyk S.

Gospodarka Wodna

|

2007

|

tom Nr 5

185-190

PL

Stosowane dotychczas metody identyfikacji rozkładu prawdopodobieństwa przepływów maksymalnych w roku są w IMGW zastępowane metodą nazywaną metodą alternatywy zdarzeń. W prezentowanej pracy metoda ta została szczegółowo omówiona z punktu widzenia jej poprawności i porównana z metodami dotychczas w Polsce stosowanymi.

EN

Methods of identification of probability distribution of the maximum flow values in the year are being replaced by the Institute of Meteorology and Water Management with the so-called method of alternative of events. The article describes this method in details from the point of view of its correctness and compares it with methods used in Poland up to now.

17

Zasady formułowania probabilistycznych modeli deszczów maksymalnych

60%

Wdowikowski M. , Wartalska K. , Kaźmierczak B. , Kotowski A.

Gaz, Woda i Technika Sanitarna

|

2023

|

tom Nr 1

22--29

PL

Zaprezentowane w pracy zasady formułowania probabilistycznych modeli na wysokość deszczów maksymalnych, opracowane na Politechnice Wrocławskiej w latach 2010-2015 [10, 12, 21], po modyfikacjach z 2019 [8] i 2020 roku [9], mogą mieć charakter uniwersalny. Proponowany pięćdziesięcioletni okres pomiarowy, do wyodrębnienia metodą POT niezależnej próby losowej deszczów, jest odpowiedni do wiarygodnej oceny częstości ich występowania od C = 1 rok do C = 50 lat. Do opisu wysokości deszczów maksymalnych, spośród ośmiu możliwych do zastosowania teoretycznych rozkładów prawdopodobieństwa, wskazano na przydatności dwóch rozkładów: Weibulla i GED. Ujednolicenie metodyki tworzenia modeli deszczów maksymalnych w Polsce umożliwi poprawne fizykalnie wzajemne porównywanie ich lokalnych wysokości i da podstawę do szacowania trendów zmian w przyszłości

EN

The principles presented in this paper for formulating heavy rainfall probabilistic models developed at the Wroclaw University of Science and Technology in 2010-2015 [2, 12, 15] after the modifications of 2019 [18] and 2020 [20] can be universal. The proposed 50-year measurement period for extracting an independent random sample of rain using the POT method is suitable for reliably assessing the frequency of occurrence from C = 1 to C = 50 years. To describe the height of the maximum rain, from among eight possible theoretical probability distributions, the usefulness of two distributions was indicated: Weibull and GED. The unification of the methodology for creating models of maximum rain in Poland will enable physically correct mutual comparison of their local heights and provide a basis for estimating trends of change in the future.

18

Niepewność pomiaru. Próba usystematyzowania pojęć i metod obliczeń

60%

Kubisa S. , Moskowicz S.

Pomiary Automatyka Kontrola

|

2004

|

tom R. 50, nr 1

32--36

PL

Przewodnik [1] nie uznaje pojęcia wartości prawdziwej, zatem unika pojęcia błędu pomiaru. W artykule wykazano, że pojęcie błędu Δγ - różnicy między wartością poprawną &;gamma a wartością prawdziwą Y upraszcza zależności określające rozszerzoną niepewność pomiaru U. Specjalistyczne oprogramowanie pozwala obliczać niepewność U w sposób ścisły, jednak dla zwiększenia wiarygodności obliczeń niezbędne jest uściślenie rozkładów prawdopodobieństwa składników błędu pomiaru. Do wstępnej oceny dokładności pomiaru oraz dla kontroli poprawności obliczeń metodą ścisłą, przydatne są przybliżone metody obliczania niepewności rozszerzonej U. Przedstawiono przykład oceny stopnia poprawności czterech metod przybliżonych.

EN

The concept of measuring uncertainty, introduced by Guide [1], provoked many discussion in the environment of metrologists. The Guide avoids to use the notions of the true value and the measurement error. It may account for incomplete understanding of the Guide`s ideas. The autors of the paper advocate the following nations: measurement result (after introducing all possible corrections) γ, true value Y=expected value Eγ of the measurement result γ (5), and measurement error Δ&gamma=γ-Y (7). The measurement results y and the measurement error Δγ are random variables. The first variable γ has a non-zero expected value Eγ, whereas the expected value EΔγ of the second variable Δγ is 0(zero) (7) - the measurement error Δγ is a centred random value. Therefore, the idea of the measurement equation - eq. (13) instead of (12) and the equation the solution of which defines an exact value of the expanded measurement uncertainty U with postulated confidence level p - eq. (10) instead of (9). Excepting the exact method of uncertainty (13), which could be performed by a specialized software, four approximated methods are used in the practice - Table 1, eq. (25). An evaluation of the methods is presented in Fig. 4. The methods III and IV may be particulary useful, because they define the lower and the upper limit of the expanded uncertainty U. Further improvement of the expanded uncertainty calculation requires searching for probability distribution of the measurement error components in the first place.

19

Application of the Pearson's distributions for characterizing the surface roughness of machine components

60%

Wiśniewski M.

Tribologia

|

2010

|

tom nr 6

229-236

EN

The family of the Pearson's distributions of probability has been presented. These distributions have been defined as the functions of the asymmetry and concentration of the random variable, i.e. the dimensionless skewness parameter Sk and the dimensionless kurtosis parameter Ku. The probability distributions of the seven Pearson’s distributions have been given. The connecting point of these distributions is a normal one. The results of the measurements of the surface roughness of a number of the unworn and worn machine elements have been presented, for which the Pearson’s analysis has been applied.

PL

Przedstawiona została rodzina rozkładów Pearsona. Rozkłady te zostały zdefiniowane jako funkcje współczynników asymetrii i skupienia rozkładu zmiennej losowej, tj. bezwymiarowych parametrów skośności Sk oraz kurtozy Ku. Podano gęstości prawdopodobieństwa dla siedmiu typów rozkładów Pearsona z punktem łączącym, będącym rozkładem normalnym. Przedstawiono wyniki pomiarów chropowatości powierzchni dla zestawu niezużytych i zużytych elementów maszyn, dla których przeprowadzono analizy zgodności według systemu Pearsona.

20

Powiązanie podejścia Francou-Rodiera z formułami na obliczanie przepływów maksymalnych rocznych o określonym prawdopodobieństwie przewyższenia

60%

Twaróg B.

Gospodarka Wodna

|

2008

|

tom Nr 6

228-237

PL

Artykuł prezentuje możliwości przybliżonej oceny wartości przepływów maksymalnych rocznych o określonym prawdopodobieństwie przewyższenia, zbudowanej na podstawie zależności wykorzystywanej w teorii Francou-Rodiera oraz rozkładu prawdopodobieństwa charakterystycznego dla wartości ekstremalnych. Zaletą w proponowanym podejściu jest to, że wielkości przepływu o określonym prawdopodobieństwie przewyższenia uwzględniają powierzchnię zlewni.

EN

The paper presents possibilities of approximate estimation of the maxi-mum annual flows of a defined excedance probability values. The estimation is based on the dependence used in the Francou-Rodier theory and on the distribution of probability characteristic for extreme values. In the proposed approach the values of the flows of a determined excedance probability take into account the catchment basin surface.