Informacja

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

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "failure prediction" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 22
Tytuł:
Being an outlier: a company non-prosperity sign?
Autorzy:
Svabova, Lucia
Durica, Marek
Powiązania:
https://bibliotekanauki.pl/articles/22446412.pdf
Data publikacji:
2019
Wydawca:
Instytut Badań Gospodarczych
Tematy:
bankruptcy prediction models
financial ratios
failure prediction
financial distress
Opis:
Research background: The state of financial distress or imminent bankruptcy are very difficult situations that the management of every company wants to avoid. For these reasons, prediction of company bankruptcy or financial distress has been recently in a focus of economists and scientists in many countries over the world. Purpose of the article: Various financial indicators, mostly financial ratios, are usually used to predict the financial distress. In order to create a strong prediction model and a statistically significant prediction of bankruptcy, it is advisable to use a deep statistical analysis of the data. In this paper, we analysed the real financial ratios of Slovak companies from the year 2017. In the phase of data preparation for further analysis, we checked the existence of outliers and found that there are some companies that are multivariate outliers because are significantly different from other companies in the database. Thus, we deeply focused on these outlying companies and analysed whether to be an outlier is a sign of financial distress. Methods: We analysed whether there are much more non-prosperous companies in the set of outlier companies and if their financial indicators are significantly different from those of the prosperous companies. For these analyses, we used testing of the statistical hypotheses, such as the test for equality of means and chi-square test. Findings & Value added: The ratio of non-prosperous companies between the outliers is significantly higher than 50 % and the attributes of non-prosperity and being an outlier are dependent. The means of almost all financial ratios of prosperous and non-prosperous companies among outliers are significantly different.
Źródło:
Equilibrium. Quarterly Journal of Economics and Economic Policy; 2019, 14, 2; 359-375
1689-765X
2353-3293
Pojawia się w:
Equilibrium. Quarterly Journal of Economics and Economic Policy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A genetic fuzzy approach to estimate operation time of transport device
Autorzy:
Smoczek, J.
Szpytko, J.
Powiązania:
https://bibliotekanauki.pl/articles/247484.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
failure prediction
fuzzy genetic system
material handling system
Opis:
The classic approach to evaluate the probability that an operational system is capable to operate satisfactorily and successfully perform the formulated tasks is based on availability that is coefficient which is determined based on the history of down-time and up-time occurring, while the risk-degree of down-time occurring strongly depends on the actual operational state of a system. The intelligence computational methods enable to create the diagnosis tools that allow to formulate the prognosis of operating time of a system and predict of failure occurring based on the past and actual information about system's operational state, especially genetic fuzzy systems (GFSs) that combine fuzzy approximate reasoning and capability to learn and adaptation. The paper presents the fuzzy rule-based inference system used to predict the operating time of exploitation system according to the specified operational conditions. The proposed algorithm was used to design the fuzzy model applied to estimate the operating time of a system between the actual time and predicted time of the next failure occurring under the stated operational parameters. The fuzzy system allows to prognoses the time of the predicted failure based on the operational parameters which are used to evaluate the actual operational state of the system. The attention in the paper is focused on the evolutionary computational techniques applied to design the fuzzy inference system. The paper proposes the genetic algorithm based on the Pittsburgh method and real-valued chromosomes used to optimize the knowledge base and parameters of antecedents and conclusions of the Takagi-Sugeno-Kang (TSK) fuzzy implications. The paper is the contribution to the GFSs, which aim is to find an appropriate balance between accuracy and interpretability, and also contribution to the research field on the diagnosis methods based on soft computing techniques. The evolutionary algorithm was tested for designing the fuzzy operating time predictor of material handling device.
Źródło:
Journal of KONES; 2011, 18, 4; 601-608
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The genetic fuzzy based proactive maintenance of a technical object
Autorzy:
Smoczek, J.
Szpytko, J.
Powiązania:
https://bibliotekanauki.pl/articles/246817.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
proactive maintenance
failure prediction
fuzzy logic
genetic algorithm
Opis:
The proactive maintenance is an effective approach to enhance the system availability through real time monitoring the current state of a system. The key part of this method is forecasting the nonoperational states for advanced warning of the failure possibility that can bring the attention of machines operators and maintenance personnel to impending danger facilitate planning preventive and corrective operations, and resources managing as well. The paper presents the HMI/SCADA-type application used to support decision-making process. The proposed approach to proactive maintenance is based on forecasting the remaining useful life of device equipment and delivering the user-defined maintenance strategy developed during system operation. The HMI/SCADA application is used to collect data in form of failures history, changes of operational conditions and performances of a monitored process between failures, as well as heuristic knowledge about process created by experienced user. The data history is used to design the predictive fuzzy models of time between failures of system equipment. The fuzzy predictive models are designed using the genetic algorithm applied to optimize the fuzzy partitions covering the training data examples, as well as to identify fuzzy predictive patterns represented by a set of rules in the knowledge base. The evolutionary learning strategy, which has been proposed in this paper, provides the effective reproduction techniques for searching the solution space with respect to optimization of knowledge base and membership functions according to the fitness function expressed as a ratio of compatibility of fuzzy partitions with data examples to root mean squares error. The proposed application was created and tested on the laboratory stand for monitoring the availability of the overhead travelling crane.
Źródło:
Journal of KONES; 2012, 19, 3; 399-405
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards a High Reliable Enforcement of Safety Regulations - A Workflow Meta Data Model and Probabilistic Failure Management Approach
Autorzy:
Thimm, H. H.
Powiązania:
https://bibliotekanauki.pl/articles/136152.pdf
Data publikacji:
2016
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
Environmental Health and Safety
workflow management
workflows
failure detection
failure prediction
Opis:
Today’s companies are able to automate the enforcement of Environmental, Health and Safety (EH&S) duties through the use of workflow management technology. This approach requires to specify activities that are combined to workflow models for EH&S enforcement duties. In order to meet given safety regulations these activities are to be completed correctly and within given deadlines. Otherwise, activity failures emerge which may lead to breaches against safety regulations. A novel domain-specific workflow meta data model is proposed. The model enables a system to detect and predict activity failures through the use of data about the company, failure statistics, and activity proxies. Since the detection and prediction methods are based on the evaluation of constraints specified on EH&S regulations, a system approach is proposed that builds on the integration of a Workflow Management System (WMS) with an EH&S Compliance Information System. Main principles of the failure detection and prediction are described. For EH&S managers the system shall provide insights into the current failure situation. This can help to prevent and mitigate critical situations such as safety enforcement measures that are behind their deadlines. As a result a more reliable enforcement of safety regulations can be achieved.
Źródło:
Transactions on Environment and Electrical Engineering; 2016, 1, 4; 19-28
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnosing corporate stability using grammatical evolution
Autorzy:
Brabazon, A.
O'Neill, M.
Powiązania:
https://bibliotekanauki.pl/articles/907637.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
ewolucja gramatyczna
prognozowanie awarii
mapowanie procesu
grammatical evolution
corporate failure prediction
mapping process
Opis:
Grammatical Evolution (GE) is a novel data-driven, model-induction tool, inspired by the biological gene-to-protein mapping process. This study provides an introduction to GE, and demonstrates the methodology by applying it to construct a series of models for the prediction of bankruptcy, employing information drawn from financial statements. Unlike prior studies in this domain, the raw financial information is not preprocessed into pre-determined financial ratios. Instead, the ratios to be incorporated into the classification rule are evolved from the raw financial data. This allows the creation and subsequent evolution of alternative ratio-based representations of the financial data. A sample of 178 publicly quoted, US firms, drawn from the period 1991 to 2000 are used to train and test the model. The best evolved model correctly classified 86 (77)% of the firms in the in-sample training set (out-of-sample validation set), one year prior to failure.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2004, 14, 3; 363-374
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applying the Anticipatory Failure Determination at a Very Early Stage of a System’s Development: Overview and Case Study
Autorzy:
Chybowski, L.
Gawdzińska, K.
Souchkov, V.
Powiązania:
https://bibliotekanauki.pl/articles/2065020.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
complex technical system
anticipatory failure determination
AFD
anticipatory failure analysis
AFA
failure prediction
Theory of Inventing Problem Solving
TRIZ
Opis:
Anticipatory Failure Determination (AFD) is a tool used in the TRIZ (Theory of Inventive Problem Solving) methodology. This article introduces its concept and describes the process of AFD in different versions of the method. The article presents the application of the AFD method at a very early state of a system’s development, i.e. its concept formulation stage, which corresponds to a technology readiness level (TRL) equal to 2. The system under analysis is a set of devices used to reduce displacement ship hull resistance. The system was modelled using functional analysis. An analysis of system resources was then carried out. Possible direct, indirect, and accident-related failures were identified. A multi-criteria analysis of the causes of system failures was conducted from which the top 10 potential failures were selected. Observations were made on the applicability of AFD in respect to systems not yet implemented.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2018, 1, 1; 205--215
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of different failure approaches in knotty wood
Autorzy:
Guindos, P.
Powiązania:
https://bibliotekanauki.pl/articles/52443.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
knotty wood
wood
comparison
failure prediction
knot
wood defect
multi-scale modelling
average stress approach
Opis:
This article presents and assesses 64 different ways for predicting the failure onset in knotty wooden beams. The aim is to provide engineers and modellers a generalview of how to evaluate the failure in wooden structural members with knots.The studied criteria included both the conventional point-based and average stress theories. Special attention was paid to the effect of the elements of the woodmesostructure, i.e. knots and fiber deviation, which can generate singular stress concentrations as notches or cracks would do in fracture mechanics. The case study consisted of predicting the failure onset of bending in structural wooden beams.A previously validated finite element model was used in order to compute the heterogeneous stresses. It was found that the knots caused considerable stress singularities so that the size of the average stress theory influenced the failure predictions by up to 23%. However, the variations generated by distinct phenomenologicalcriteria were in general much smaller. The application of the average stress theory in large stress integration volumes is strongly recommended when predicting the failure in wood members.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 193
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of data from measuring sensors for prediction in production process control systems
Analiza danych z czujników pomiarowych do predykcji w systemach kontroli procesów produkcyjnych
Autorzy:
Rymarczyk, Tomasz
Przysucha, Bartek
Kowalski, Marcin
Bednarczuk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/408521.pdf
Data publikacji:
2019
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
Cox model
time to failure prediction
production control
intelligent platform
model Coxa
predykcja uszkodzeń
sterowanie produkcją
inteligentna platforma
Opis:
The article presents a solution based on a cyber-physical system in which data collected from measuring sensors was analysed for prediction in the production process control system. The presented technology was based on intelligent sensors as part of the solution for Industry 4.0. The main purpose of the work is to reduce data and select the appropriate covariate to optimise modelling of defects using the Cox model for a specific mechanical system. The reliability of machines and devices in the production process is a condition for ensuring continuity of production. Predicting damage, especially its movement, gives the ability to monitor the current state of the machine. In a broader perspective, this enables streamlining the production process, service planning or control. This ensures production continuity and optimal performance. The presented model is a regressive survival analysis model that allows you to calculate the probability of failure occurring over a given period of time.
Artykuł przedstawia rozwiązanie oparte na systemie cyber-fizycznym, w którym analizowano dane zbierane z czujników pomiarowych do predykcji w systemie kontroli procesów produkcyjnych. Przedstawiona technologia została oparta na inteligentnych czujnikach pomiarowych jako element rozwiązania dla Przemysłu 4.0. Głównym celem pracy jest redukcja danych i wybór odpowiedniego kowariantu w celu optymalizacji modelowania usterek za pomocą modelu Coxa dla konkretnego układu mechanicznego. Niezawodność pracy maszyn i urządzeń w procesie produkcyjnym jest warunkiem zapewnienia ciągłości produkcji. Przewidywanie uszkodzenia, a zwłaszcza jego momentu daje możliwość monitorowania bieżącego stanu maszyny. W szerszej perspektywie umożliwia to usprawnienie procesu produkcji, planowania serwisu, czy kontroli. Zapewnia to utrzymanie ciągłości produkcji i optymalnej jej wydajności. Przedstawiony model jest regresywnym modelem analizy przeżycia, który pozwala na obliczanie prawdopodobieństwa wystąpienia awarii w określonym czasie.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2019, 9, 4; 26-29
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the gas network failure and failure prediction using the Monte Carlo simulation method
Analiza awaryjności sieci gazowych oraz prognozowanie awarii z zastosowaniem symulacyjnej metody Monte Carlo
Autorzy:
Tchórzewska-Cieślak, B.
Pietrucha-Urbanik, K.
Urbanik, M.
Powiązania:
https://bibliotekanauki.pl/articles/301501.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
failure of gas network
Monte Carlo method
analysis of the failure structure
failure prediction
awaryjność sieci gazowej
metoda Monte Carlo
analiza struktury awaryjności
prognozowanie awaryjności
Opis:
The scope of the article includes the analysis of the gas network failure based on a material obtained from field tests covering the years 2004-2014, conducted on the gas network of 120 thousand city, allowing to specify the failure rate of the gas network with division into material, pressure and pipelines diameter and indicate the main causes of failure on gas networks. On the base of the results of this analysis the Monte Carlo method to predict failures in gas pipe network has been presented.
Artykuł swoim zakresem obejmuje analizę awaryjności sieci gazowej na podstawie uzyskanego materiału z badań eksploatacyjnych obejmujących lata 2004-2014 prowadzonych na terenie Zakładu Gazowniczego w 120 tys. mieście, co pozwoliło na podanie intensywności uszkodzeń sieci gazowych z podziałem na materiał, ciśnienie i średnice rurociągów oraz podanie głównych przyczyn powstawania awarii na sieciach gazowych. Na podstawie wyników analizy zaprezentowano zastosowanie metody Monte Carlo do prognozowania awarii sieci gazowych.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 2; 254-259
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of anisotropic strength criteria in the biaxial stress state
Porównanie anizotropowych kryteriów wytrzymałości w dwuosiowym stanie naprężeń
Autorzy:
Garab, J.
Szalai, J.
Powiązania:
https://bibliotekanauki.pl/articles/52698.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
anisotropic strength criterion
biaxial compression test
complex microstructure
mechanical property
physical property
wood property
planar stress state
failure prediction number
biaxial test
Opis:
In our study, three phenomenological strength criteria (the von Mises criterion, the Tsai-Wu criterion, and the Ashkenazi criterion) were compared based on experimental data. The goal of this study was to decide which strength theory describes properly the failure of wood under biaxial load. Formerly, a set of biaxial tests was performed on Norway spruce (Picea abies [L.] Karst.) specimens. As a result hundreds of biaxial strength data are available. Failure criteria were validated in these planar stress states. Theoretical and experimental background was presented and tensor components were calculated from engineering strength for each strength criteria. Failure prediction data was determined by the three theories. The results show that out of the three criteria the Ashkenazi strength criterion best describes the failure of wood in planar stress state.
Ze względu na skomplikowaną mikrostrukturę, właściwości fizyczne i mechaniczne drewna i materiałów drewnopochodnych są anizotropowe. Z powodu tej złożonej struktury, przewidywanie wytrzymałości drewna jest trudne i komplikuje się jeszcze bardziej w złożonych (dwu- i trójosiowych) stanach naprężeń. W niniejszej pracy porównano trzy fenomenologiczne anizotropowe kryteria wytrzymałości (von Mises’a, Tsai - Wu i Ashkenazi’ego) na podstawie danych doświadczalnych uzyskanych uprzednio dla świerka (Picea abies [L.] Karst.). Celem tego porównania było ustalenie, która teoria wytrzymałościowa przewiduje właściwie powstawanie defektów w drewnie w dwuosiowym stanie naprężeń. Na podstawie posiadanych danych doświadczalnych wyznaczono wartości wskaźników przewidywania defektu wraz z ich współczynnikami zmienności. Uzyskane wyniki pokazują, że w płaskim stanie naprężeń kryterium wytrzymałościowe Ashkenazi’ego najlepiej przewiduje powstawanie uszkodzeń w drewnie. Kolejnym etapem analiz będzie porównanie anizotropowych kryteriów wytrzymałościowych dla trójosiowego stanu naprężeń oraz badania innych gatunków drewna w wieloosiowych stanach naprężeń.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2010, 53, 183
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of occurrence of the situations endangering inland waterways passenger ships and the environment
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260408.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
inland waterways ship
prediction of failure probability
availability indices of ship devices
Opis:
In this paper a four-state semi-Markov model of occurrence of the situations endangering inland waterways passenger ships, is presented. The model was elaborated in the form of the semi - Markov process, values of which are kinds of the states interpreted as the following situations : normal, complicated, hazardous and emergency. An example of realization of the process of changing the situations possible to occur during trips of inland waterways passenger ships, is presented. Also, formulae are attached, which make it possible to determine probabilities of occurrence of the mentioned situations during ship trips. The formulae were interpreted as safety measures of operation of inland waterways ship. Possibility of performing statistical investigations which could provide data for determining the mentioned probabilities was also stated.
Źródło:
Polish Maritime Research; 2006, S 2; 38-42
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Durability of Dimensionally Stable Electrode in High-Rate Electroplating Process Condition Using Accelerated Life Test
Autorzy:
Park, Sung Cheol
Jung, Yeon Jae
Koo, Seokbon
Lee, Kee-Ahn
Son, Seong Ho
Powiązania:
https://bibliotekanauki.pl/articles/2049186.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
durability
prediction
dimensionally stable electrode
accelerated life test
failure mechanism
Opis:
In order to the long-term stability of DSE for electroplating process, the lifetime equations were calculated from the results of the accelerated life testing, and the lifetime of DSE was predicted. The nano-embossing pre-treatment led to 2.65 times in the lifetime of DSE. The degradation mechanism of DSE with a thick metal oxide layer for applied highly current density process condition was identified. The improvement of durability of DSE seems to be closely related to adhesion between titanium plate and mixed metal oxide layer.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 675-678
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decision tree based model of business failure prediction for Polish companies
Autorzy:
Durica, Marek
Frnda, Jaroslav
Svabova, Lucia
Powiązania:
https://bibliotekanauki.pl/articles/19090954.pdf
Data publikacji:
2019
Wydawca:
Instytut Badań Gospodarczych
Tematy:
decision trees
prediction model
financial ratios
business failure
Polish companies
Opis:
Research background: The issue of predicting the financial situation of companies is a relatively young field of economic research. Its origin dates back to the 30's of the 20th century, but constant research in this area proves the currentness of this topic even today. The issue of predicting the financial situation of a company is up to date not only for the company itself, but also for all stakeholders. Purpose of the article: The main purpose of this study is to create new prediction models by using the method of decision trees, in achieving sufficient prediction power of the generated model with a large database of real data on Polish companies obtained from the Amadeus database. Methods: As a result of the development of artificial intelligence, new methods for predicting financial failure of the company have been introduced into financial prediction analysis. One of the most widely used data mining techniques in this field is the method of decision trees. In the paper, we applied the CART and CHAID approach to create a model of predicting the financial difficulties of Polish companies. Findings & Value added: For the creation of the prediction model, a total of 37 financial and economic indicators of Polish companies were used. The resulting decision trees based prediction models for Polish companies reach a prediction power of more than 98%. The success of the classification for non-prosperous companies is more than 83%. The created decision tree-based prediction models are useful mainly for predicting the financial difficulties of Polish companies, but can also be used for companies in another country.
Źródło:
Oeconomia Copernicana; 2019, 10, 3; 453-469
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A combined universal generating function and physics of failure Reliability Prediction Method for an LED driver
Autorzy:
Fan, Liming
Wang, Kunsheng
Fan, Dongming
Powiązania:
https://bibliotekanauki.pl/articles/1841791.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
reliability prediction
LED driver
reliability modelling
physics of failure
universal generating function
Opis:
The accurate and effective reliability prediction of light emitting diode (LED) drivers has emerged as a key issue in LED applications. However, previous studies have mainly focused on the reliability of electrolytic capacitors or other single components while ignoring circuit topology. In this study, universal generating function (UGF) and physics of failure (PoF) are integrated to predict the reliability of LED drivers. Utilizing PoF, lifetime data for each component are obtained. A system reliability model with multi-phase is established, and system reliability can be predicted using UGF. Illustrated by a two-channel LED driver, the beneficial effects of capacitors and MOSFETs for the reliability of LED drivers is verified. This study (i) provides a universal numerical approach to predict the lifetime of LED drivers considering circuit topology, (ii) enhances the modelling and reliability evaluation of circuits, and (iii) bridges the gap between component and circuit system levels.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 74-83
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-to-failure forecast for corroded shell of above-ground steel tank used to store liquid fuels
Prognoza czasu do awarii skorodowanej powłoki naziemnego zbiornika stalowego do magazynowania paliw płynnych
Autorzy:
Maslak, Mariusz
Pazdanowski, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1853645.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
powłoka skorodowana
zbiornik stalowy
prawdopodobieństwo uszkodzenia
prognoza trwałości
czas do awarii przewidywany
czas zdatności
steel tank
corroded shell
failure probability
durability prediction
time-to-failure forecast
survival time
Opis:
An original simplified procedure to estimate the remaining service time of corroded shell of an on-the-ground steel tank used to store liquid fuels is presented in this paper. Current corrosion progress trend, identified a’posteriori based on the obligatory technical condition monitoring, is extrapolated to the future tank service time under the assumption that the conditions of service would not change and no renovation or modernization works would be undertaken. Failure probability understood as exhaustion of the capability to safely resist the loads applied due to the corrosion progress constitutes the measure of the sought uptime. For comparative purposes several effective inference methods have been proposed for the same input data, based on formally qualitatively different but corresponding description measures. It has been shown, that in the analysis of this type the representative values, usually expressed as quantiles of probability distributions describing random variables in use, need not be specified to verify the safety condition. The proposed algorithm is based on fully probabilistic considerations, and those, according to Authors’ opinion, by their nature lead to more reliable, and at the same time, objective estimates.
Przedstawiono uproszczoną, autorską procedurę szacowania pozostającego czasu zdatności skorodowanej powłoki naziemnego użytkowanego zbiornika stalowego wykorzystywanego do magazynowania paliw płynnych. W proponowanym algorytmie postępowania dotychczasowy trend postępu korozji, identyfikowany a posteriori na podstawie pomiarów dokonywanych w ramach obowiązkowych ocen stanu technicznego, zostaje ekstrapolowany na czas przyszłego użytkowania zbiornika, przy założeniu że sposób jego wykorzystania nie ulegnie zmianie i nie będą prowadzone jakiekolwiek prace remontowe lub modernizacyjne. Miarą oceny poszukiwanego czasu zdatności jest narastające wraz z postępem korozji prawdopodobieństwo awarii rozumianej jako wyczerpanie możliwości bezpiecznego przenoszenia obciążeń. Awaria nie oznacza przy tym natychmiastowego zniszczenia obiektu ale stan, w którym monitorowane prawdopodobieństwo osiągnęło poziom graniczny, niemożliwy do zaakceptowania przez użytkownika. Dla tych samych danych wejściowych, w celach porównawczych, zaproponowano różne sposoby efektywnego wnioskowania, oparte na formalnie jakościowo odmiennych ale odpowiadających sobie miarach opisu. Potwierdzono, że w tego typu analizie do weryfikacji warunku bezpieczeństwa nie ma potrzeby specyfikacji jakichkolwiek wartości reprezentatywnych, wyznaczanych na ogół jako kwantyle rozkładów prawdopodobieństwa opisujących poszczególne zmienne losowe, w szczególności losowe obciążenie i losową nośność rozważanej powłoki. Proponowany algorytm opiera się bowiem na wnioskowaniu w pełni probabilistycznym, a to, zdaniem autorów, ze swej natury pozwala oceniającemu na uzyskanie bardziej wiarygodnych a przy tym obiektywnych oszacowań. Prezentowana procedura została zweryfikowana numerycznie na przykładzie prognozy opracowanej dla istniejącego stalowego zbiornika paliwowego z dachem pływającym, zlokalizowanego w jednej z baz paliwowych Polski południowej.
Źródło:
Archives of Civil Engineering; 2021, 67, 1; 303-322
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 22

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