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Tytuł:
The Weibull lifetime model with randomised failure-free time
Autorzy:
Sulewski, Piotr
Szymkowiak, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/2156948.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
Weibull lifetime model
randomised failure-free time
compound Weibull distributions
Opis:
The paper shows that treating failure-free time in the three-parameter Weibull distribution not a constant, but as a random variable makes the resulting distribution much more flexible at the expense of only one additional parameter.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 59-76
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction model of the pandemic spreading based on weibull distribution
Autorzy:
Guľáš, Ľuboš
Talian, Matej
Szabo, Stanislav
Semrádová, Beáta
Powiązania:
https://bibliotekanauki.pl/articles/2204124.pdf
Data publikacji:
2022
Wydawca:
STE GROUP
Tematy:
pandemics
prediction model
weibull distribution
Opis:
Pandemics have the potential to cause immense disruption of our everyday activities and has impact on the communities and societies mainly through the restrictions applied to the business activities, services, manufacturing, but also education, transportation etc. Therefore, it is important to create suitable prediction models to establish convenient methods for the planning of the operations and processes to cope with the difficulty. In this paper, the prediction model for the spread of the viral disease in term of the estimated maximal weekly confirmed cases and weekly deaths using the Weibull distribution as a theoretical model for statistical data processing is presented. The theoretical prediction model was applied and confirmed on the data available for the whole world and compared to the situation in Europe and Slovakia for the pandemic waves and can be used for the more precise prediction of the pandemic situation and to enhance planning of the activities and processes regarding to the restrictions applied during the worsening pandemic situation.
Źródło:
Management Systems in Production Engineering; 2022, 2 (30); 179--186
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo method for reliability of parallel system with dependent failures of component
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069174.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
stochastic process
Weibull distribution
dependency
Opis:
A problem of parallel system reliability with dependent failures of components is presented in the paper. It is assumed that lifetimes of components are independent random variable having Weibull distribution. We take under consideration a parallel (in reliability meaning) system consisting of n independent at the beginning of work and identical components. We assume that a load of the working system affects on the reliability of its components and the load of the system is distributed on all working components. Therefore, a failure rate of each component is changeable during run of the system and depends on a number of working elements at this point in time. As a model of the system failures we construct a stochastic process which value at the moment t denotes the number of working components. Generally it is neither Markov nor semi-Markov process. To assess the reliability characteristics of the system we simulate this stochastic process using the Monte-Carlo method and we calculate values of nonparametric kernel density and reliability functions estimators.
Źródło:
Journal of Polish Safety and Reliability Association; 2016, 7, 1; 67--72
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability of a Collective Wastewater Treatment Plant
Autorzy:
Bugajski, P.
Chmielowski, K.
Kaczor, G.
Powiązania:
https://bibliotekanauki.pl/articles/125059.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
wastewater treatment plant
technological reliability
Weibull theory
Opis:
The paper discusses technological reliability of a collective wastewater treatment plant (WTP). The WTP capacity expressed as population equivalents (PE) was 22,500. The research was conducted in 2013 and 2014 and it involved the collection and physical and chemical analysis of 101 samples of raw and treated sewage. Reliability analysis was based on Weibull reliability theory. Reliability of retaining organic compounds defined as BOD5 was 68%, and for biogenic compounds, such as total nitrogen and total phosphorus, it was 92% and 88%, respectively.
Źródło:
Journal of Ecological Engineering; 2016, 17, 4; 143-147
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimating parameters of the Weibull diameter distribution for Gmelina arborea in Nimbia Forest Reserve, Nigeria
Autorzy:
Shamaki, S. B.
Akindele, S. O.
Marshall, P. L.
LeMay, V. M.
Powiązania:
https://bibliotekanauki.pl/articles/1075794.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Gmelina arborea
Nimbia Forest Reserve
Weibull distribution
Opis:
Parameters of the Weibull diameter distribution were estimated for Gmelina (Gmelina arborea) plantation in Nimbia Forest Reserve. Stratified random sampling was employed to select five plots of 20 × 20 m from each forest bit that serves as management unit, thereby having a total of 20 plots for the study. Stump diameter (Dst), diameter at breast height (Dbh), diameter at middle and top positions (Dm and Dt) of trees, and tree height for all the selected trees were measured. Average Dbh measured was 16.33 cm and the mean tree height 6.85 m. Pseudo coefficient of determination (Pseudo R2), residual mean square error, Anderson-Darling, and Kolmogorov-Smirnov goodness-of-fit statistics were considered as model selection criteria. Weibull cumulative density function (Weibull-CDF) was the best fit method for Gmelina compared with the Weibull probability density function based on the goodness-of-fit statistics generated. The diameter distribution models produced are considered only efficient for tree stands of seven years rotation age, while additional site factors like spacing, density and silvicultural treatments are required for better models, hence the need for establishing permanent sample plots (PSP) in order to get additional information from re-measurements of the plots.
Źródło:
World Scientific News; 2019, 118; 209-219
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The technical object reliability evaluation based on the parametric and momentary failures
Autorzy:
Lindstedt, P.
Manerowski, J.
Borowczyk, H.
Powiązania:
https://bibliotekanauki.pl/articles/242760.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
reliability
Weibull function
parametric failure
momentary failure
Opis:
The presented paper concerns with the technical object reliability evaluation based on the parametric and momentary failures during the process of object operating. The real world data observation shows that in the case of high quality technical objects the catastrophic failure events are too rare to the credible evaluation of the object’s reliability. For that reason, the parametric and momentary failures are in the centre of attention in this paper. The set of analysed failures was obtained with the classifiers of the field data provided by the monitoring system (the failure alarms) and the diagnostic system (the functional and technical condition parameters deviation). The changes of the functioning condition potential are used to determine the symptoms of momentary failures and the changes in the potential of the technical condition to determine the symptoms of parametric failures (non-total). The assumed reliability characteristics model has the form R(t) = f(_, Rb(t), Rc(t)), (where: Rb(t) and Rc(t) – the estimators of reliability for parametric and momentary failures, symbol ‘_’ denotes catastrophic failures not covered). For the identification of R (t) as an analytical function, the estimators are computed with the field data. The Weibull distribution function due to its flexibility is often used. Such is the case in this paper. Two parameters a and b known as the scale and the shape parameters are estimated with the computerized procedure realizing least-square method. The presented examples show good fit quality even for small set of data.
Źródło:
Journal of KONES; 2016, 23, 2; 239-246
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of production-related characteristics regarding their influence on the fatigue strength of additively manufactured components
Autorzy:
Zeißig, Michaela
Jablonski, Frank
Powiązania:
https://bibliotekanauki.pl/articles/2204622.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
additive manufacturing
fatigue strength
Weibull distribution
FEM
Opis:
In order to further enhance the application of additive manufacturing (AM) processes, such as the laser powder bed fusion (L-PBF) process, reliable material data are required. However, the resulting specimen properties are significantly influenced by the process parameters and may also vary depending on the material used. Therefore, the prediction of the final properties is difficult. In the following, the effect of residual stresses on the fatigue strength of 316L steel, a commonly used steel in AM, is investigated using a Weibull distribution. The underlying residual stress distributions as a result of the building process are approximated for two building directions using finite element (FE) models. These imply significantly different distributions of tensile and compressive residual stresses within the component. Apart from the residual stresses, the impact of the mean stress sensitivity is discussed as this also influences the predicted fatigue strength values.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 2; 288--291
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Moc testu Kołmogorowa dla weryfikowania hipotezy o wykładniczym rozkładzie prawdopodobieństwa
Power Kolmogorov test to verify the hypothesis of exponential distribution
Autorzy:
Rogowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/315448.pdf
Data publikacji:
2013
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
rozkład Weibulla
test Kołmogorowa
Weibull distribution
Kolmogorov test
Opis:
W artykule oszacowano metodą symulacyjną moc testu λ Kołmogorowa dla hipotezy złożonej o wykładniczym rozkładzie prawdopodobieństwa wobec hipotezy alternatywnej, że rozkład prawdopodobieństwa w populacji jest rozkładem Weibulla (dla wybranych wartości parametru kształtu i liczności próby n = 100). Obliczono również numerycznie granicę dolną mocy testu z wykorzystaniem rozkładu granicznego.
The article estimated using simulation power λ Kolmogorov test for the composite hypothesis of ex ponential probability distribution against the alternative hypothesis that the probability distribution of the population is Weibull distribution (with the selected shape parameter and sample size n=100). Also calculated numerically lower limit power test by using the limiting distribution.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2013, 14, 3; 1193-1202
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Demand forecasting in a business based on experts’ opinions – an application of weibull distributions
Autorzy:
Dittmann, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/424785.pdf
Data publikacji:
2013
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
demand
demand forecasting
experts’ opinions
Weibull distribution applications
Opis:
Demand forecasts in a business may be constructed by various methods, e.g. by using Type-I formal models, or by using type-II formal models based on experts’ opinions. The experts can be the business’s managers or persons from outside of the studied business. The experts can not only construct forecasts, but also subjectively specify the probability of them coming true. In this article, the Weibull distribution is described, a distribution that may be applied in the process of constructing product demand forecasts for a business. The methodology for constructing a point forecast is explained, along with the methods for evaluating the chances of the forecast coming true and the methods for judging the probability connected with sales profitability.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2013, 1(39); 52-60
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statystyczna analiza awarii pojazdów samochodowych
Failure analysis of cars
Autorzy:
RUMIANOWSKI, Roman
Powiązania:
https://bibliotekanauki.pl/articles/456949.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Rzeszowski
Tematy:
statystyka
rozkład Weilbulla
niezawodność
statistics
Weibull distribution
failure analysis
Opis:
Opracowanie prezentuje zastosowanie rozkładu Weibulla do analizowania częstości wystę-powania awarii w używanych samochodach osobowych. W artykule prezentowane są przykłady dystrybuanty rozkładu awaryjności dla kilku wybranych modeli samochodów.
The paper presents a model for calculating the occurrence of failures in cars using the Weibull distribution. Empirical cumulative distribution curve is analyzed for a few car models.
Źródło:
Edukacja-Technika-Informatyka; 2016, 7, 1; 13-17
2080-9069
Pojawia się w:
Edukacja-Technika-Informatyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas turbine reliability model based on tangent hyperbolic reliability function
Autorzy:
Djeddi, A. Z.
Hafaifa, A.
Salam, A.
Powiązania:
https://bibliotekanauki.pl/articles/280120.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
reliability estimation
reliability algorithms
lifetime distribution
Weibull distribution
availability
Opis:
The present work deals with the exploration of a new model proposed for the reliability analysis of industrial production systems. This proposed model is mainly based on the tangent hyperbolic function, where the survival function is determined and used in the lifetime distribution modeling taking into account of estimation the parameters of the proposed function. On the other side, tests validation is performed using the real data of a gas turbine installation. The obtained results allow the modeling of damage effects, hence the prediction of the performance of the examined gas turbine using the proposed model gives good results in terms of validity.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 723-730
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterizations of uniform and exponential distributions via moments of the kth record values randomly indexed
Autorzy:
Grudzień, Zofia
Szynal, Dominik
Powiązania:
https://bibliotekanauki.pl/articles/1339203.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
sample
record values
exponential
order statistics
Weibull distributions
uniform
Opis:
We characterize uniform and exponential distributions via moments of the kth record statistics. Too and Lin's (1989) results are contained in our approach.
Źródło:
Applicationes Mathematicae; 1996-1997, 24, 3; 307-314
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technological reliability of sewage treatment plant with the Pomiltek Mann type bioreactor
Autorzy:
Kurek, Karolina
Bugajski, Piotr
Operacz, Agnieszka
Młyński, Dariusz
Wałęga, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/292901.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
pollution indicators
technological reliability
wastewater treatment plant
Weibull method
Opis:
The aim of the work was to determine the technological reliability of the selected pollution indicators removal BOD5, CODCr and total suspension from the sewage treatment plant working with the bioreactor Pomiltek Mann type. Wastewater treatment plant which is a subject of this study is located in Lesser Poland, in Siepraw commune. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, CODCr and total suspended solids. Physico-chemical analyses of raw and treated wastewater, were carried out in the period from 2003 to 2014 (11 years). The research period included measured values of pollutions indicators in 38 samples of raw and treated sewage. For each of pollution indicators descriptive statistic, percentage reduction (n) and treatment plant reliability factors (RF) were calculated. Average reduction for BOD5 and TSS was on level equal 94%, only for COD the average reduction was lower and was on level 89%. The reliability values determined by Weibull method, were: 75% (BOD5), 90% (CODCr) and 89.5% (TSS). The reliability results have been lower than the presented by literature source, which means that work of wastewater treatment plant in Siepraw was not satisfied in 11 years of research.
Źródło:
Journal of Water and Land Development; 2020, 46; 146-152
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Infrared Drying on the Drying Kinetics and the Quality of Mango (Mangifera indica) Powder
Autorzy:
Nguyen, Phuoc-Bao-Duy
Nguyen, Thi-Van-Linh
Nguyen, Thi-Thuy-Dung
Powiązania:
https://bibliotekanauki.pl/articles/28408451.pdf
Data publikacji:
2024-03-01
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
antioxidant activity
fruit powder
phenolics
pulp drying
Weibull model
Opis:
Mango powder is a nutrient-dense substance that can be used directly or as a supplement in food items. However, due to the high sugar content, the removal of moisture from mango was difficult. This study investigated an infrared drying technique for removing moisture from mango pulp to produce powder products. The experiment was designed in a three-factor full factorial design with the following variables: drying temperature (70, 75, and 80°C), maltodextrin content (0, 6, and 9 g/100 g pulp), and total soluble solid content (11 and 16°Brix). The findings indicated that the Weibull model was the most appropriate for describing the moisture removal of mango pulp during infrared drying. Higher temperature and maltodextrin content, along with reduced total soluble solid content, resulted in improved quality of the mango powder. Furthermore, the optimal drying conditions for mango powder were found as 11°Brix, 80°C, and 9% maltodextrin content, which could ensure the highest retention of total phenolics (59.874%), retention of reducing sugars (71.044%), total acidity (10.141%), and retention of DPPH radical scavenging activity (65.051%). To fully benefit from the rewards of infrared drying, it is essential to establish suitable pretreatment conditions or use additives to preserve component quality.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2024, 74, 1; 69-81
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Calculation of Material Reliability Using Surface Roughness Feature Based on Plasma Material Interaction Experiment Results
Autorzy:
Pahsa, Alper
Aydoğdu, Yıldırım
Göktaş, Fahrettin
Powiązania:
https://bibliotekanauki.pl/articles/27312789.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
tokamak
material reliability
Weibull
divertor
PMI
Plasma Material Interaction
Opis:
The choice of reactor structural material design must take into account the TOKAMAK fusion reactors' structural reliability. Due to their high levels of heat and energy, fusion reactions have significant deformation effects, which reduce the efficiency of energy production in reactors. Material selection, erosion and damage, heat and stress management, reliability analysis, maintenance, and inspection are crucial elements in determining how reliable fusion reactors are. The focus of this work is on material selection and reliability analysis based on these parameters. The most common wall materials used in fusion reactors are tungsten, beryllium, steel, or graphite. It is advised to utilize aluminum because harmful Beryllium dust limits the study of this element. For this purpose, a target of aluminum samples is established with a plasma of He ions created by glow discharge. The dependability of the samples is determined by calculating the Weibull Distribution and measuring the roughness of the sample surfaces following exposure.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 3; art. no. 169815
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for estimating the probability distribution of the lifetime for new technical equipment based on expert judgement
Autorzy:
Andrzejczak, Karol
Bukowski, Lech
Powiązania:
https://bibliotekanauki.pl/articles/2038033.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
uncertainty
expert elicitation of lifetime
quantile function
Weibull distribution
Opis:
Managing the exploitation of technical equipment under conditions of uncertainty requires the use of probabilistic prediction models in the form of probability distributions of the lifetime of these objects. The parameters of these distributions are estimated with the use of statistical methods based on historical data about actual realizations of the lifetime of examined objects. However, when completely new solutions are introduced into service, such data are not available and the only possible method for the initial assessment of the expected lifetime of technical objects is expert methods. The aim of the study is to present a method for estimating the probability distribution of the lifetime for new technical facilities based on expert assessments of three parameters characterizing the expected lifetime of these objects. The method is based on a subjective Bayesian approach to the problem of randomness and integrated with models of classical probability theory. Due to its wide application in the field of maintenance of machinery and technical equipment, a Weibull model is proposed, and its possible practical applications are shown. A new method of expert elicitation of probabilities for any continuous random variable is developed. A general procedure for the application of this method is proposed and the individual steps of its implementation are discussed, as well as the mathematical models necessary for the estimation of the parameters of the probability distribution are presented. A practical example of the application of the developed method on specific numerical values is also presented.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 4; 757-769
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An inflationary inventory model with time dependent demand with Weibull distribution deterioration and partial backlogging under permissible delay in payments
Autorzy:
Basu, M.
Sinha, S.
Powiązania:
https://bibliotekanauki.pl/articles/969730.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
inflation
partial backlogging
Weibull distribution
permissible delay in payments
Opis:
This paper proposes to present a general inventory model with due consideration to the factors of time dependent partial backlogging and time dependent deterioration. It also takes into account the impact of inflation, time-dependent demand and permissible delay in payments.
Źródło:
Control and Cybernetics; 2007, 36, 1; 203-217
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Experimental Comparison of Popular Estimation Methods for the Weibull, Gamma and Gompertz Distributions
Autorzy:
Żerda, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/1373468.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
parameter estimation
Weibull distribution
gamma distribution
Gompertz distribution
MSE
Opis:
The aim of this study was to describe some parametric estimation methods for the Weibull, gamma and Gompertz distributions and to identify among them estimators the most efficient in practical applications. Techniques which are considered as traditional methods, like the maximum likelihood (MLE) and the method of moments (MM) estimation but also some newer and less commonly used techniques like the Lmoment estimator (LME), least-square estimator (LSE), generalized spacing estimator (GSE) and percentile estimator (PE) were presented. The application of each method was demonstrated in a simulation study using data sets generated for different distribution parameters and sample sizes. Discussed estimators were compared in terms of their efficiency and bias measured by mean-square errors (MSE) based on the simulations results.
Źródło:
Schedae Informaticae; 2011, 20; 67-82
0860-0295
2083-8476
Pojawia się w:
Schedae Informaticae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimisation of the preventive maintenance plan of a series components system with Weibull hazard function
Autorzy:
Duarte, J. C.
Soares, C. G.
Powiązania:
https://bibliotekanauki.pl/articles/2069578.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
availability
hazard function
Weibull distribution
preventive maintenance
series components
Opis:
In this paper we propose an algorithm to calculate the optimum frequency to perform preventive maintenance in equipment that exhibits Weibull hazard function and constant repair rate in order to ensure its availability. Based on this algorithm we have developed another one to solve the problem of maintenance management of a series system based on preventive maintenance over the different system components. We assume that all components of the system still exhibit Weibull hazard function and constant repair rate and that preventive maintenance would bring the system to the as good as new condition. The algorithm calculates the interval of time between preventive maintenance actions for each component, minimizing the costs, and in such a way that the total downtime, in a certain period of time, does not exceed a predetermined value.
Źródło:
Journal of Polish Safety and Reliability Association; 2007, 1; 67--73
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using the Weibull ++ software in water supply network failure analysis
Autorzy:
Żywiec, Jakub
Powiązania:
https://bibliotekanauki.pl/articles/105442.pdf
Data publikacji:
2019
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
failure
reliability
water supply
Weibull++
zaopatrzenie w wodę
niezawodność
uszkodzenie
Opis:
The water supply network is a basic element of the water distribution subsystem and its task is to provide consumers with water of appropriate quality, in the required quantity, under appropriate pressure, at any time and at an acceptable price. To fulfil these tasks, the water supply network should have an appropriate level of operational reliability. The paper presents an analysis of the causes of water pipes failures using the Weibull++ software. The analysis was based on the operational data from 2018 obtained from the water supply company. The data included the failure book specifying the date and place of the failure, the cause of the failure, diameter and material of the damaged pipe. The probability density function for the failure of water pipes and its cumulative distribution function have been determined. The impact of individual types of failure causes on the failure of the water supply network was determined. The results provide information about the probability of failures of the water supply network depending on their cause. These results can be used in further analyses of the reliability and safety of water supplies to consumers.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2019, 66, 3; 37-45
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rock bursts prediction based on analyzing maximal phenomena of seismic emission in the INGEO system
Możliwości predykcji wstrząsów na podstawie analizy zjawisk maksymalnych emisji sejsmicznej w systemie INGEO
Autorzy:
Cianciara, B.
Isakow, Z.
Siciński, K.
Cianciara, A.
Powiązania:
https://bibliotekanauki.pl/articles/1361960.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
emisja sejsmiczna
metoda hazardu
strumień zdarzeń
model Weibull`a
wstrząsy
zagrożenie sejsmiczne
seismic emission
hazard method
stream of events
Weibull model
rock bursts
seismic hazard
Opis:
Predicting the time of rock bursts in the INGEO system is based on the analysis of seismic emission registered in a seismic-acoustic system. Emission signals are generated by rock mass fracturing due to mining exploitation. Such emission is characterized by huge activity of different phenomena which enables to carry out a correct statistical analysis with the use of the hazard method, achieving suitably high resolution of interpretation results. The hazard method is based on the analysis of maxmal phenomena, i.e. phenomena of maximal energy. The use of this method allows to eliminate disturbances to a large extent and, at the same time, enables to assess the probability of high-energy phenomena (rock bursts). The hazard analysis is conducted on the basis of two essential qualities of seismic emission, such as energy of phenomena and intervals between successive phenomena. These qualities are random variables of statistical distribution described by the Weibull model. Using this model one can estimate the parameters of statistical distribution of those qualities which are the basis to determine hazard parameters. The analysis is conducted based on measurement data collected from the T window, i.e. time interval measured by hours. The window is moved with the d step and the calculations are repeated. The hazard parameters were used to define the risk function FWt(QE,T) which is the measure of rock bursts hazard. This function depends on real time t which is determined as the time of the T window right edge. It is also the basis to work out rock burst hazard criteria. It is important to note that the moment a rock burst occurs is a random variable and can be determined with the accuracy of its confidence interval, with certain probability.
Predykcja czasu wystąpienia wstrząsów w systemie INGEO oparta jest na analizie emisji sejsmicznej rejestrowanej w systemie sejsmoakustycznym. Sygnały emisji są generowane pękaniem górotworu wywołanym eksploatacją. Emisja taka charakteryzuje się dużą aktywnością zjawisk, która umożliwia prowadzenie poprawnej analizy statystycznej metodą hazardu, uzyskując również odpowiednio wysoką rozdzielczość wyników interpretacji. Metoda hazardu oparta jest na analizie zjawisk maksymalnych, czyli zjawisk o maksymalnej energii. Zastosowanie tej metody daje znaczną eliminację zakłóceń, a jednocześnie umożliwia ocenę prawdopodobieństwa wystąpienia zjawisk wysokoenergetycznych (wstrząsów). Analiza hazardu realizowana jest na podstawie dwóch podstawowych cech emisji sejsmicznej, a mianowicie: energii zjawisk, oraz odstępów czasu między kolejnymi zjawiskami. Cechy te są zmiennymi losowymi o rozkładzie statystycznym, który jest opisywany modelem Weibull`a. Na podstawie tego modelu prowadzona jest estymacja parametrów rozkładu statystycznego tych cech, które stanowią podstawę do wyznaczania parametrów hazardu. Analiza realizowana jest w oparciu o dane pomiarowe pobierane z okna T, czyli przedziału czasu rzędu godzin. Okno to jest przesuwane z krokiem d i powtarzane są obliczenia. Wykorzystując parametry hazardu zdefiniowano funkcję ryzyka FWt(QE,T), będącą miarą zagrożenia wystąpieniem wstrząsów. Funkcja ta jest zależna od czasu realnego t, który jest określony, jako czas prawego brzegu okna T. Stanowi ona podstawę do opracowania kryteriów stanu zagrożenia tąpaniami, jak również jej przebieg może być wykorzystany do oceny czasu wystąpienia wstrząsów. Należy podkreślić, że moment wystąpienia wstrząsu jest zmienną losową i może być wyznaczony z dokładnością do swojego przedziału ufności, z określonym prawdopodobieństwem.
Źródło:
Mining – Informatics, Automation and Electrical Engineering; 2016, 54, 4; 5-10 [tekst ang.], 50-55 [tekst pol.]
2450-7326
2449-6421
Pojawia się w:
Mining – Informatics, Automation and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas turbine reliability estimation to reduce the risk of failure occurrence with a comparative study between the two-parameter Weibull distribution and a new modified Weibull distribution
Autorzy:
Djeddi, Ahmed Zohair
Hafaifa, Ahmed
Iratni, Abdelhamid
Kouzou, Abdellah
Powiązania:
https://bibliotekanauki.pl/articles/2096209.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
failure analysis
malfunction analysis
availability
reliability estimation
failure occurrence
maintenance plan
gas turbine
two-parameter Weibull
modified Weibull
analiza uszkodzeń
dostępność
ocena niezawodności
turbina gazowa
Opis:
Responding to the needs of quality and robustness of analysis and management of degradation of equipment, to increase their life cycle and to expand these facilities to become more and more sophisticated and agronomic. This work proposes a contribution to increase the survival of a gas turbine, installed in a gascompression plant, with a comparative study between the two-parameter Weibull distribution. A new modified Weibull distribution was proposed also to reduce the risk of occurrence of failure in this rotating machine. A Statistical analysis and validation on the synthesis of turbine's reliability data and failures were considered, with a particular focus on the use of this data to increase the availability of this type of machine. So, developing a maintenance plan based on their reliability indices for scheduled inspections.
Źródło:
Diagnostyka; 2022, 23, 1; 1--18
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie rozkładu Weibulla do oceny wytrzymałości nasion grochu
Application of Weibull distribution for assessment of pea seed strength
Autorzy:
Łysiak, G.
Powiązania:
https://bibliotekanauki.pl/articles/291143.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
właściwości wytrzymałościowe
rozkład Weibulla
groch
strength-related properties
Weibull statistics
pea
Opis:
W pracy przedstawiono wyniki analiz wybranych właściwości wytrzymałościowych nasion grochu przy wykorzystaniu statystyki Weibulla. Pojedyncze nasiona o wilgotności w zakresie 4-14% ściskano na maszynie wytrzymałościowej Zwick. Określono wartości sił i odkształceń w momencie pęknięcia nasiona oraz na podstawie rozkładu ich wyników określono wartości parametrów m i rozkładu Weibulla. Wartości parametru kształtu m malały wraz ze wzrostem wilgotności nasion. Większy spadek obserwowano w przypadku rozkładu wartości odkształceń do punktu pęknięcia. Wraz ze wzrostem wilgotności zmniejszały się prostoliniowo wartości parametru dla sił w momencie pęknięcia oraz rosły nieliniowo dla odkształceń. Obserwowane różnice wskazują na możliwości rozszerzenia oceny zachowania materiałów biologicznych w procesie ściskania o informacje uzyskane przy zastosowaniu do analiz statystyki Weibulla.
The work presents the results of analyses of selected strength-related properties of pea seeds by using Weibull statistics. Single seeds with humidity from 4 to 14% were squeezed in Zwick testing machine. The force and deformation values were established in the moment when the seeds broke, and based on the distribution of the results the values of the parameters m and ⎴ of Weibull distribution were determined. The shape parameter m values decreased with the increased humidity of the seeds. More significant drop was observed in the case of distribution of deformation values up to the breaking point. Together with the increase of humidity, the parameter values ⎴ dropped rectilinearly for the forces at the moment of breaking and rose in a nonlinear way for the deformations. The observed differences indicate the possibilities of extending the assessment of behaviour of biological materials in the process of squeezing by the information obtained by using Weibull statistics for the analyses.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 6(81), 6(81); 41-48
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mixed control chart adapted to the truncated life test based on the Weibull distribution
Autorzy:
Khan, N.
Aslam, M.
Kim, K.-J.
Jun, C. -H.
Powiązania:
https://bibliotekanauki.pl/articles/406432.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
life test
Weibull distribution
attribute chart
binomial distribution
average run length
Opis:
The design of a new mixed attribute control chart adapted to a truncated life test has been pre-sented. It was assumed that the lifetime of a product follows the Weibull distribution and the number of failures was observed using a truncated life test, where the test duration was specified as a fraction of the mean lifespan. The proposed control chart consists of two pairs of control limits based on a binomial distribution and one lower bound. The average run length of the chart was determined for various levels of shift constants and specified parameters. The efficiency of the chart is compared with an existing control chart in terms of the average run length. The application of the proposed chart is discussed with the aid of a simulation study.
Źródło:
Operations Research and Decisions; 2017, 27, 1; 43-55
2081-8858
2391-6060
Pojawia się w:
Operations Research and Decisions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The modified Bagdonavičius-Nikulin goodness-of-fit test statistic for the right censored distributional validation with applications in medicine and reliability
Autorzy:
Yousof, Haitham M.
Ali, M. Masoom
Aidi, Khaoula
Ibrahim, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/18105193.pdf
Data publikacji:
2023-09-08
Wydawca:
Główny Urząd Statystyczny
Tematy:
inverted Weibull distribution
censored validation
Bagdonavičius-Nikulin
goodness-of-fit testing
Opis:
A modified version of Bagdonavičius-Nikulin goodness-of-fit statistical test is presented for validation under the right censor case. Simulation via Barzilai-Borwein algorithm is performed for assessing the right-censorship estimation method. Four right censored data sets are analyzed under the new modified test statistic for checking the distributional validation.
Źródło:
Statistics in Transition new series; 2023, 24, 4; 1-18
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
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