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Wyszukujesz frazę "Semi-Markov process" wg kryterium: Wszystkie pola


Tytuł:
Decision problem for infinite duration semi-Markov process
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069519.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
semi-Markov decision processes
optimization
Howard algorithm
linear programing
Opis:
In the paper there are presented basic concepts and some results of the theory of semi-Markov decision processes. The optimization problem for the infinite duration SM process is connsider in the paper. The Howard algoritm which enables to find the optimal stationary strategy is also discussed here. The algorithm is applied in a decision problem concerning the two components renewable series system is. It is also shown that this algorithm is equivalent to the some linear programing problem.
Źródło:
Journal of Polish Safety and Reliability Association; 2014, 5, 2; 33--40
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concept of semi-Markov process
Koncepcja procesu semi-Markowa
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/221956.pdf
Data publikacji:
2016
Wydawca:
Akademia Marynarki Wojennej. Wydział Dowodzenia i Operacji Morskich
Tematy:
semi-Markov process
probabilities matrix
proces semi-Markova
macierz prawdopodobieństw
Opis:
This paper provides the definitions and basic properties related to a discrete state space semi-Markov process. The semi-Markov process is constructed by the so called Markov renewal process that is a special case the two-dimensional Markov sequence. The Markov renewal process is defined by the transition probabilities matrix, called the renewal kernel and an initial distribution or by another characteristics which are equivalent to the renewal kernel. The counting process corresponding to the semi-Markov process allows to determine concept of the process regularity. In the paper are also shown the other methods of determining the semi-Markov process. The presented concepts are illustrated a simple example.
Artykuł przedstawia definicje i podstawowe cechy procesu semi-Markowa dyskretnego stanu przestrzeni. Proces semi-Markova jest zbudowany przez tzw. proces odnawiania Markova, który jest specjalnym przypadkiem dwuwymiarowego ciągu Markova. Proces odnawiania Markova jest zdefiniowany przez macierz prawdopodobieństw przejściowych, zwaną jądrem odnawiania, i początkowy rozkład lub przez inne charakterystyki, które są równe jądru odnawiania. Proces obliczeniowy odpowiadający procesowi semi-Markova pozwala na określenie koncepcji regularności procesu. W artykule przedstawiono również pozostałe metody określania procesu semi-Markova. Przedstawione koncepcje są zaprezentowane na prostym przykładzie.
Źródło:
Zeszyty Naukowe Akademii Marynarki Wojennej; 2016, R. 57 nr 3 (206), 3 (206); 25-36
0860-889X
Pojawia się w:
Zeszyty Naukowe Akademii Marynarki Wojennej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decision problem for a finite states change of semi-Markov process
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069327.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
semi-Markov decision processes
optimization
Howard algorithm
linear programming
Opis:
In the paper there are presented basic concepts and some results of the theory of semi-Markov decision processes. The algorithm of optimization a SM decision process with a finite number of state changes is discussed here. The algorithm is based on a dynamic programming method. To clarify it the SM decision model for the maintenance operation is shown.
Źródło:
Journal of Polish Safety and Reliability Association; 2015, 6, 1; 95--100
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Attempts at calculating chosen contributors with regard to the Semi- Markov process and the Weibull function distribution
Autorzy:
Zajac, M.
Kierzkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2069531.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
Semi Markov process
exponential distribution
availability
transient probabilities
Opis:
The main aim of this article is the presentation of the way of making calculation with the application of the semi-Markov processes, with the continuous time t, where non-exponential distribution function is going to be applied. These type of calculations were published but the time there was approaching infinity. Engineering practice proves that the lack of solutions of this issue leads to obtainment of solutions that are encumbered with errors. This article is the first attempt of the error analysis.
Źródło:
Journal of Polish Safety and Reliability Association; 2011, 2, 1; 217--222
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The random failure rate
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069577.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
random failure rate
semi-Markov process
Opis:
A failure rate of the object is assumed to be a stochastic process with nonnegative, right continuous trajectories. A reliability function is defined as an expectation of a function of a random failure rate process. The properties and examples of the reliability function with the random failure rate are presented in the paper. A semi-Markov process as the random failure rate is considered in this paper.
Źródło:
Journal of Polish Safety and Reliability Association; 2007, 1; 143--149
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Safety and risk evaluation of Stena Baltica ferry in variable operation conditions
Autorzy:
Kołowrocki, K.
Soszyńska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069680.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
safety function
operation process
semi-markov process
Opis:
Basic safety structures of multi-state systems of components with degrading safety states related to their variable operation conditions are defined. For these systems the conditional and unconditional multi-state safety functions are determined. A semi-markov process for the considered systems operation modelling is applied. Further, the paper offers an approach to the solution of a practically important problem of linking the multi-state systems safety models and the systems operation processes models. Theoretical definitions and results are illustrated by the example of their application in the safety and risk evaluation of the Stena Baltica ferry operating at the Baltic Sea. The ferry transportation system has been considered in varying in time operation conditions. The system safety structure and its components safety functions were changing in variable operation conditions.
Źródło:
Journal of Polish Safety and Reliability Association; 2009, 2; 231--240
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-Markov processes: application in system reliability and maintenance
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069404.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
maintenance
semi-Markov process
semi-Markov perturbed processes
Opis:
The author’s monograph “Semi-Markov Processes: Application in System Reliability and Maintenance” which will be published by Elsevier in 2014 is presented. The paper is composed of an introduction, the monograph contents, conclusions and the references the monograph contents is based on.
Źródło:
Journal of Polish Safety and Reliability Association; 2014, 5, 1; 57--62
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model-building adaptive critics for semi-Markov control
Autorzy:
Gosavi, A.
Murray, S.
Hu, J.
Ghosh, S.
Powiązania:
https://bibliotekanauki.pl/articles/91878.pdf
Data publikacji:
2012
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
adaptive critics
learning algorithm
semi-Markov process
decision process
Opis:
Adaptive (or actor) critics are a class of reinforcement learning algorithms. Generally, in adaptive critics, one starts with randomized policies and gradually updates the probability of selecting actions until a deterministic policy is obtained. Classically, these algorithms have been studied for Markov decision processes under model-free updates. Algorithms that build the model are often more stable and require less training in comparison to their model-free counterparts. We propose a new model-building adaptive critic, which builds the model during the learning, for a discounted-reward semi-Markov decision process under some assumptions on the structure of the process. We illustrate the use of our algorithm with numerical results on a system with 10 states and a real-world case-study from management science.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2012, 2, 1; 43-58
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary statistical identification and prediction of the container gantry crane operation process
Autorzy:
Kołowrocki, K.
Soszyńska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069653.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
semi-Markov process
system operation process
sojourn time
estimation
Opis:
In the paper a Semi-markov process is used to construct a general model of complex industrial systems’ operation processes. Main parameters of this model are defined and its main characteristics are determined as well. In particular case, for a gantry crane, the operation states are defined, the relationships between them are fixed and particular model of its operation process is constructed and finally its main characteristics are determined.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 173--180
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The semi-Markov model of energy state changes of the main marine internal combustion engine and method for evaluating its operation during ship voyage
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260072.pdf
Data publikacji:
2011
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
operation
energy
semi-Markov process
piston internal combustion engine
Opis:
The article presents a method for evaluating the operation of internal combustion engines used as the main engines in the propulsion systems of sea-going ships in various operating conditions. This method enables calculating the engine operation value based on the theory of semi-Markov processes and mathematical statistics. What is noteworthy, the operation of the examined internal combustion engines is compared to a physical quantity which is expressed in the form of a number with the measure unit called joule-second. a model having the form of a semi-Markov process is proposed to describe the energy state changes taking place in the main engines during their operation. Also proposed is the use of the point and interval estimation at a given confidence level â for determining the value of the energy converted in the engine during its operation for the known and unknown standard energy deviation treated as the random variable. The semi-Markov model of changes of the energy converted in the engine during its operation is presented in a general form. The above model was used for determining the ship’s main engine operation, which is in the examined case a function of the energy converted in particular energy states, the expected value of the time of duration of these states and the probability of their existence. These probabilities compose the limiting distribution of the semi-Markov process, the values of which are the specified main engine energy states.
Źródło:
Polish Maritime Research; 2011, 4; 36-42
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systems reliability analysis in variable operation conditions
Autorzy:
Soszyńska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069605.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability function
semi-markov process
large multi state system
Opis:
The semi-markov model of the system operation process is proposed and its selected parameters are defined. There are found reliability and risk characteristics of the multi-state series- “m out of k ” system. Next, the joint model of the semi-markov system operation process and the considered multi-state system reliability and risk is constructed. The asymptotic approach to reliability and risk evaluation of this system in its operation process is proposed as well.
Źródło:
Journal of Polish Safety and Reliability Association; 2007, 2; 319--330
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conception of valuation of combustion engine operation
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/244104.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
heat
operation
energy
work
semi-Markov process
combustion engine
Opis:
The work provides a proposal of interpretation showing operation in terms of values being compared to a physical quantity with the unit of measure called joule-second, just like operations of Hamilton and Maupertius demonstrated in classical mechanics. Operation in this interpretation is also considered in quantum mechanics, referring to body electromagnetic radiation source of which operation is characterized by Planck constant. An original method of analysis and evaluation of machine operation is herein presented in the energetic aspect, as the result of applying the theory of semi-Markov processes. In order to give grounds for usability of such interpreted operation it has been employed the model describing changes in energy of combustion engines, in the form of state-discrete and time-continuous semi-Markov process. The process is thus a semi-Markov model of getting worse combustion engine operation run with the lapse of time and regaining the initial energetic state of the engine after its refurbishment. The limiting distribution of the process has been determined with probabilities of occurring the distinguished energetic states of mentioned engines. The paper shows that the proposed interpretation for the operation enables making a graph of operation, which demonstrates engine operation in the form of field. The attention is paid that the engine operation in the presented version has got the advantage that can be expressed as a quantity with the joule-second as a unit of measure and as a graph in the form of operation field. The coordinate system for presenting the operation as a field, proposed in this paper, refers to the known in thermodynamics possibility of expressing the energy conversion sorts like work and heat (according to the conception of Clapeyron and Belpaire) in the form of fields.
Źródło:
Journal of KONES; 2008, 15, 2; 89-96
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of complex technical systems operation processes
Autorzy:
Soszyńska, J.
Kołowrocki, K.
Blokus-Roszkowska, A.
Guze, S.
Powiązania:
https://bibliotekanauki.pl/articles/2069640.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
system operation
semi-Markov process
statistical identification
transportation systems
Opis:
There is presented the contents of the training course addressed to industry. The curriculum of the course includes the methods, algorithms and procedures for identification of the unknown parameters of the operations processes of the complex technical systems and their application in practice. It is based on theoretical backgrounds concerned with the semi-markov modelling of the complex technical systems operations processes, the statistical methods of identification of the complex technical systems operation processes. The illustrations of the proposed methods and procedures practical application in port, shipyard and maritime transport sector are included.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 2; 287--308
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of complex technical systems operation processes (part 2)
Autorzy:
Soszyńska, J.
Kołowrocki, K.
Blokus-Roszkowska, A.
Guze, S.
Powiązania:
https://bibliotekanauki.pl/articles/2069634.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
system operation
semi-markov process
statistical identification
transportation systems
Opis:
There is presented the contents of the training course addressed to industry. The curriculum of the course includes the methods, algorithms and procedures for identification of the unknown parameters of the operations processes of the complex technical systems and their application in practice. It is based on theoretical backgrounds concerned with the semi-markov modelling of the complex technical systems operations processes, the statistical methods of identification of the complex technical systems operation processes. The illustrations of the proposed methods and procedures practical application in port, shipyard and maritime transport sector are included.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 2; 309--328
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-renewal multistate system with Semi-Markov components
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069483.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
Semi-Markov process
multistate system
multistate reliability functions
binary representation
Opis:
The paper deals with non-renewal multistate monotone systems consisting of multistate components which are modeled by the semi-Markov processes. In the case of a non-renewal system the multistate reliability functions of the system components and the whole system are discussed. All presented concepts and models are illustrated by simple numerical examples.
Źródło:
Journal of Polish Safety and Reliability Association; 2014, 5, 1; 63--70
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of theory of semi-Markov processes to determining distribution of probabilistic process of marine accidents resulting from collision of ships
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260618.pdf
Data publikacji:
2014
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
critical manoeuvre
port
probability
semi-Markov process
sea-going ship
Opis:
In this paper is presented possible application of the theory of semi-Markov processes to elaborating an eight-state model of the process of occurrence of serviceability state and unserviceability states of sea-going ships making critical manoeuvres during their entering and leaving the ports. In the analysis it was taken into account that sea-going ships are in service for a very long time t (t → ∞). The model was elaborated to determine the probability (P0) of correct execution of critical manoeuvres during ship’s entering and leaving the port as well as the probabilities Pj(j = 1, 2, 3, …, 7) of incorrect execution of critical manoeuvres by a ship, that leads to marine accidents. It was assumed that such accidents result from: ship’s grounding on port approaching fairway, collision with a ship on port approching fairway, collision with a pierhead during passing through port entrance, collision with a hydrotechnical structure during ship’s passing through port channels, collision with a port quay during coming alongside it and collision with a ship already moored to the quay. The probability (P0) was assumed a measure of safe execution of a critical manoeuvre. The probability characterizes possibility of avoiding any collision during ship’s entering and leaving the port. The probability Pa = 1 – P0 was assumed a measure of occurrence of a collsion and - consequently - marine accident. The probability Pa was interpreted as a sum of the probabilities Pj(j = 1, 2, 3, …, 7) of occurrence of all the selected events. In summing up the paper, attention was drawn to its merits which - in opinion of this author - are crucial for research on real process of accidents during entering the port and leaving it by sea-going ship in difficult navigation conditions.
Źródło:
Polish Maritime Research; 2014, 1; 9-13
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex technical systems safety prediction
Autorzy:
Soszyńska-Budny, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069501.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
safety function
complex system
Semi-Markov process
system operation process
Opis:
There are presented general safety analytical models of complex multistate technical systems related to their operation processes. They are the integrated general models of complex technical systems, linking their multistate safety models and their operation processes models and considering variable at the different operation states safety structures and their components safety parameters. The conditional safety functions at the system particular operation states and independent of the system particular operation states the unconditional safety function and the risk function of the complex technical systems are defined. These joint models of the safety and the variable in time system operation processes are constructed for multistate series, parallel, “m out of n”, consecutive “m out of n: F”, series-parallel, parallel-series, series-“m out of k”, “mi out of li”-series, series-consecutive “m out of k: F” and consecutive “mi out of li: F”-series systems. The joint models are applied to determining safety characteristics of these systems related to their varying in time safety structures and their components safety characteristics. Under the assumption that the considered systems are exponential, the unconditional safety functions of these systems are determined. The proposed models and methods are applied to the safety analysis, evaluation and prediction of the one subsystem of the port grain transportation system related to varying in time their operation processes, structures and components safety parameters.
Źródło:
Journal of Polish Safety and Reliability Association; 2014, 5, 2; 127--142
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the theory of semi-Markov processes to the development of a reliability model of an automotive vehicle
Zastosowanie teorii procesów semi-Markowa do opracowania modelu niezawodnościowego samochodu
Autorzy:
Girtler, J.
Ślęzak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1364785.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz. Przemysłowy Instytut Motoryzacji
Tematy:
niezawodność
proces semimarkowski
samochód
automotive vehicle
reliability
semi-Markov process
Opis:
A possibility of applying the theory of semi-Markov (semimarkovian) processes to the description of the reliability of an automotive vehicle has been presented, with taking a passenger car as an example. In the car considered, such constructional systems (functional components) as engine with fuel, lube oil, and coolant feeding systems, clutch, gearbox, drive shaft, driving axle, steering and suspension system, braking system, electrical system, body with chassis, and measuring and monitoring equipment have been distinguished. A reliability model of the car has been developed in the form of a semi-Markov process, which is a single-state model. The set of reliability states has been built as consisting of one state of car serviceability and ten states of the functional components as specified above. A graph of changes in these states has been shown and an initial distribution and a functional matrix representing changes in the said reliability states of the car have been defined. Formulas have been derived that define the boundary distribution of the process of changes in the technical states of such a car. This distribution represents the probability of the car being serviceable and unserviceable due to a failure of any of the functional components mentioned above. The possibility of using statistics to estimate the probabilities of changes in the said car reliability states has been presented. A possibility of applying the theory of semi-Markov processes to the investigation of car reliability in the case of defining the instantaneous distribution of the process of changes in the car reliability states has also been mentioned.
W artykule przedstawiono możliwość zastosowania teorii procesów semi-Markowa (semimarkowskich) do opisu niezawodności samochodu, na przykładzie samochodu osobowego. W rozważaniach uwzględniony został samochód, w którym wyróżniono takie węzły konstrukcyjne (zespoły funkcjonalne) jak: silnik z układami zasilania czynnikami energetycznymi (paliwem, olejem smarowym i cieczą chłodzącą), sprzęgło, skrzynia biegów, wał napędowy, most napędowy, zespół kierowniczy z zawieszeniem, zespół hamulcowy, zespół urządzeń elektrycznych, nadwozie wraz z podwoziem i zespół urządzeń kontrolno-pomiarowych. Opracowano model niezawodnościowy samochodu w formie procesu semimarkowskiego, który jest modelem jedenastostanowym. Do zbioru stanów niezawodnościowych samochodu zakwalifikowano stan zdatności samochodu oraz dziesięć stanów niezdatności wymienionych zespołów funkcjonalnych. Przedstawiono graf zmian tych stanów oraz określono rozkład początkowy i macierz funkcyjną odwzorowującą zmiany wymienionych stanów niezawodnościowych samochodu. Wyprowadzone zostały wzory określające rozkład graniczny procesu zmian stanów technicznych takiego samochodu. Rozkład ten stanowią prawdopodobieństwa przebywania samochodu w stanie zdatności oraz w stanach niezdatności wskutek uszkodzenia dowolnego z wymienionych jego zespołów funkcjonalnych. Przedstawiono możliwość zastosowania statystyki do oszacowania prawdopodobieństw zmiany wspominanych stanów niezawodnościowych samochodu. Zasygnalizowano także możliwość zastosowania teorii procesów semimarkowskich do badań niezawodności samochodów w przypadku opracowania rozkładu chwilowego procesu zmian ich stanów niezawodnościowych.
Źródło:
Archiwum Motoryzacji; 2012, 2; 15-27
1234-754X
2084-476X
Pojawia się w:
Archiwum Motoryzacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability analysis of a system subjected to two-state operation process
Autorzy:
Kuligowska, E.
Powiązania:
https://bibliotekanauki.pl/articles/358995.pdf
Data publikacji:
2013
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
reliability analysis
simulation methods
operation states
semi-Markov process
modeling
Opis:
The paper presents analytical and Monte Carlo simulation methods applied to the reliability evaluation of a system operating at two different operation states. A semi-Markov process is applied to construct the system operation model and its main characteristics are determined. Analytical linking of this operation model with the system reliability model is proposed to get a general reliability model of the system operating at two varying operation conditions and to find its reliability characteristics. The application of Monte Carlo simulation based on this general model to the reliability evaluation of this system is proposed as well. The results obtained from those two considered methods are evaluated.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2013, 36 (108) z. 1; 100-104
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo approach to identification of maritime ferry operation process
Autorzy:
Otremba, Z.
Soszyńska, J.
Targowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/2069652.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
operation process
semi-Markov process
complex systems
Monte Carlo simulation
Opis:
The paper is concerned with the identification of operation processes of complex technical systems. The convenient tools suggested for analyzing these complex technical systems operation processes are semi-markov modeling and Monte Carlo simulation. The paper describes the proposed approach as well as the possibility of its practical application to identification of the operation process of a maritime ferry.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 187--192
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the process of operating an aircraft from aspect of flight safety and effectiveness
Autorzy:
Żurek, J.
Powiązania:
https://bibliotekanauki.pl/articles/245779.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
air transport
durability
relibility
semi-Markov process
availability factor
Opis:
This paper presents the method of evaluation of a technical object as immersed in a logistic system with regard to its durability, the operational availability/readiness and the utilisation factor. These factors decide upon the object's effectiveness. For this evaluation probabilistic models from the theory of reliability and of the semi-Markov process were used. For the purpose of this paper as a technical object serves an aircraft. The process of operating an aircraft consists in using its resources to function accumulated during the process of its manufacture and resulting from a periodic regeneration of these resources in order to maintain its capability of being further operated. For the sake of better understanding our discussion we will refer to the sald 'flying craft' as an aircraft (including also other 'means of transport' into this notion). The paper in principle concerns on analysis of safe durability and aircraft availability/readiness analysis. The availability factor of an object in a logistic system expresses the prospective possibility of an effective action. The degree of utilisation of this „potential" for apassenger plane is represented by the occupancy factor. A product ctors of availability and occupancy can describe the overall effectiveness indicator, which characterises the availability and the market demand.
Źródło:
Journal of KONES; 2009, 16, 3; 527-536
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A general model of industrial systems operation processes related to their environment and infrastructure
Autorzy:
Kołowrocki, K.
Soszyńska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069711.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
system operation process
semi-markov process
system in varying operation
Opis:
The operation process of the complex industrial system is considered and its operation states are introduced. The semi-markov process is used to construct a general probabilistic model of the considered complex industrial system operation process. To build this model the vector of probabilities of the system operation process initials operation states, the matrix of probabilities of the system operation process transitions between the operation states, the matrix of conditional distribution functions and the matrix of conditional density functions of the system operation process conditional sojourn times in the operation states are defined. To describe the system operation process conditional sojourn times in the particular operation states the uniform distribution, the triangle distribution, the double trapezium distribution, the exponential distribution, the Weibull distribution and the normal distribution are suggested. Under these all assumptions from the constructed general model the main characteristics of the system operation process are find. The mean values of the system operation process conditional sojourn times in particular operation states having these distributions are calculated. Moreover, the unconditional distribution functions of the system operation process unconditional sojourn times in the particular operation states, the mean values of the system operation process unconditional sojourn times in the particular operation states, the limit values of the transient probabilities of the system operation process at the particular operation states and the mean values of the system operation process total sojourn times in the particular operation states are determined.
Źródło:
Journal of Polish Safety and Reliability Association; 2008, 2; 223--226
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stochastic model of the load spectrum for main engines of sea-going ships
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/243406.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
semi-Markov process
load
diesel engine
main engine
sea ship
Opis:
The paper presents possibility of applying the theory of semi-Markov processes for probabilistic description of load spectrum for diesel engines employed for ship propulsion, so for main engines. The considerations include output power characteristics for this kind of engines. The characteristics have enabled formulating a four-member set of states of the process of load on the engines. The theory of semi-Markov processes has been applied for describing the real process of loads on the mentioned engines. This theory has made possible building a model of the engine loads in form of a continuous-time semi-Markov process with a four-state set of values. Properties of a Darboux continuous function, which allow considering the engine loads as the discrete-states and continuous-time processes, have been used to build the model. In consequence a limiting distribution of the occurring process of successive states of engine loads could be determined. The distribution is the probabilities of staying a sea-going ship main engine in successive states of load. The distribution is characterized by the spectrum of loads on this kind of engines. The presented model can be developed by taking into account many states of the process of main engines loading as the need is to make such a probabilistic description of the process that provides possibility of rational control of the operating process.
Źródło:
Journal of KONES; 2007, 14, 3; 187-193
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of complex technical systems operation processes
Autorzy:
Soszyńska, J.
Kołowrocki, K.
Blokus-Roszkowska, A.
Guze, S.
Powiązania:
https://bibliotekanauki.pl/articles/2069638.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
system operation
semi-Markov process
system operation prediction
transportation systems
Opis:
There is presented the contents of the training course addressed to industry. The curriculum of the course includes the methods, algorithms and procedures for prediction of the operation processes of the complex technical systems and their application in practice. It is based on the theoretical backgrounds concerned with the semi-markov modelling of the complex technical systems operation processes and on the methods of these processes prediction. The illustrations of the proposed methods and procedures practical application in port, shipyard and maritime transport sector and are included.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 2; 497--510
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Four-state stochastic model of changes in the reliability states of a motor vehicle
Model stochastyczny czterostanowy zmian stanów niezawodnościowych samochodu
Autorzy:
Girtler, J.
Ślęzak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1366153.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
niezawodność
proces semimarkowski
samochód
reliability
semi-Markov process
motor vehicle
Opis:
The properties of semi-Markov processes have been generally characterized and the applicability of the theory of such processes to the determining of the reliability of motor cars and other road vehicles has been explained. A formal description of the process of changes in the motor vehicle technical states considered as reliability states and a model of this process in the form of a one-dimensional stochastic process have been presented. The values of this process are the technical states of the motor vehicle in question that have significant practical importance. A four-state set of states interpreted as follows has been adopted: full (complete) serviceability, partial (incomplete) serviceability, task-limiting serviceability,and complete (total) unserviceability. Based on the initial distribution adopted and the functional matrix worked out, the boundary distribution of the process of changes in the technical (reliability) states of the motor vehicle has been defined. The probability of the vehicle being fully serviceable has been considered a measure of the vehicle reliability for a long period of vehicle operation. A possibility of defining the vehicle reliability in the form of a probability that a task would also be fulfilled by the vehicle being partially serviceable has also been indicated.
W artykule scharakteryzowano ogólnie własności procesów semimarkowskich i uzasadniono możliwości ich zastosowania do określenia niezawodności samochodów i innych pojazdów drogowych. Przedstawiono formalny opis procesu zmian stanów technicznych samochodów uznanych za stany niezawodnościowe oraz model tego procesu w postaci jednowymiarowego procesu stochastycznego. Wartościami tego procesu są występujące w czasie eksploatacji stany techniczne samochodów, mające istotne znaczenie praktyczne. Przyjęto czterostanowy zbiór stanów o następującej interpretacji: stan zdatności pełnej (całkowitej), stan zdatności częściowej (niepełnej, niecałkowitej), stan niepełnej zdatności zadaniowej i stan niezdatności pełnej (całkowitej). Na podstawie przyjętego rozkładu początkowego i opracowanej macierzy funkcyjnej został określony rozkład graniczny procesu zmian stanów technicznych (niezawodnościowych) samochodu. Prawdopodobieństwo istnienia stanu zdatności pełnej (całkowitej) samochodu zostało uznane za miarę jego niezawodności w długim okresie czasu eksploatacji. Wskazano też na możliwość określenia niezawodności samochodu w formie prawdopodobieństwa, w którym uwzględniony został przypadek wykonania zadania przez samochód także wtedy, gdy znajduje się on w stanie zdatności częściowej.
Źródło:
Eksploatacja i Niezawodność; 2013, 15, 2; 156-160
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An importance measure for multi-component systems with Semi-Markov dynamics
Autorzy:
Hellmich, M.
Berg, H. P.
Powiązania:
https://bibliotekanauki.pl/articles/2069417.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
multi-component system
importance measure
Semi-Markov process
state space model
Opis:
We consider semi-Markov reliability models of multi-component systems with a discrete state space, general enough to include systems with maintenance or repair. We assume that for all system states the functioning or failure of each component is specified. In this setup we propose a component importance measure which is close in spirit to the classical steady state Barlow–Proschan importance measure for repairable binary coherent systems. We discuss our importance measure to some extent, highlighting the relation to the classical Barlow–Proschan measure, and present formulas expressing it in terms of quantities easily obtained from the building blocks of the semi-Markov process. Finally an example of a two-component cold standby system with maintenance and repair is presented which illustrates how our importance measure can be used in practical applications.
Źródło:
Journal of Polish Safety and Reliability Association; 2012, 3, 1; 147--156
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying the issue of reducing the emission of harmful compounds in the exhaust gas from marine main engines and description of the emission process of these compounds in probabilistic approach
Autorzy:
Łosiewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/258884.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship’s main engine
semi-Markov process
Diesel engine
harmful substance
Opis:
The article discusses the results of actions performed by marine engine manufacturers towards the reduction of emission of harmful substances in the exhaust gas from these engines. The discussion is limited to main engines produced by MAN B&W. A model is proposed to describe the process of emission of harmful substances from Diesel engines based on the semi-Markov process, discrete in states and continuous in the operating time. The states of this process are: engine ability state (s1) and engine inability state (s2). A method to calculate probabilities P1 and P2 of the appearance of states s1 and s2 is proposed. State s1 is interpreted as corresponding to the inequality ekek(dop), where ek represents the mass of harmful substances emitted by the engine during its operation and ek(dop) is the maximum mass of emission of these substances permitted by relevant regulations.
Źródło:
Polish Maritime Research; 2017, 2; 89-95
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-Markov model of quality state changes of a selected transport system
Autorzy:
Landowski, B.
Muślewski, Ł.
Knopik, L.
Bojar, P.
Powiązania:
https://bibliotekanauki.pl/articles/241811.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport system
efficiency
operation process
maintenance process
semi-Markov process
simulation tests
Opis:
The study deals with the problems connected with evaluation and analysis of transport systems operational quality. The research object is a real, sociotechnical system (of the type H-M-E) whose functional quality is affected by: operators, equipment and technical state of he operated vehicles and the environmental impact. A scheme of an assessment model was built on the basis of a developed concept of a system operational quality and a random process was defined to be used for the analysis. The assessment process involves investigating the variability degree of properties included in the resultant model in a given time and determining whether and to what degree the obtained values meet the requirements of the system appropriate operational quality. On the basis of the above assumptions and in result of experimental tests, four qualitative states of a transport system functioning, which represent intervals of values of the obtained grades in given time moments, were distinguished. The study presents a model of system operation qualitative state changes developed with the use of Markov chain inserted into a certain semi-Markov process. A graph and a matrix for probability of transition between the states were created and boundary distributions of the process were determined on the basis of experimentally obtained data. A system of equations was determined for the distinguished Markov chain, on the basis of which a mathematical model for assessment and control of operational quality of selected types of transport systems will be built.
Źródło:
Journal of KONES; 2017, 24, 4; 141-148
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of operation efficiency of selected transport systems
Autorzy:
Muślewski, Ł.
Lewalski, M.
Aleksandrowicz, P.
Landowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/245072.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport system
efficiency
operation process
maintenance process
semi-Markov process
simulation tests
Opis:
This study deals with the problems connected with evaluation of technical systems efficiency of particular transport systems. The main goal of such a system operation is its effective functioning, through rational control of its particular activities and subsequent processes. A literature analysis of the definition of the efficiency term has been made. A real transport system has been accepted to be the research object. The system belongs to the group of sociotechnical systems in which evaluation of its operation efficiency depends on performance of operators, transport means and the impact of environmental factors. Criteria and methods of operation efficiency evaluation have been determined in this study as well as assessment indexes for transport systems. It has been shown that evaluation of a repair efficiency has a large influence on the efficiency of the whole system operation, especially the influence of secondary failure repairs, on the values of particular efficiency indexes. A semi-markov model of operation and maintenance of transport means used in the research object has been developed. This model provides the basis for evaluation of the influence of the processes involved in preparing transport means for service on the system operation efficiency. Moreover, the research also describes how to verify the developed model and present its simulation tests. The study is summarized with conclusions formulated based on the evaluation of the influence of the operation and maintenance processes on the investigated transport system operation efficiency.
Źródło:
Journal of KONES; 2016, 23, 3; 351-358
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the change of qualitative states of transportation system operation
Autorzy:
Muślewski, Ł
Knopik, L.
Woropay, M.
Powiązania:
https://bibliotekanauki.pl/articles/247633.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
system operation quality
model
Markov chain
semi-Markov process
expected coast
Opis:
This paper deals with the problems connected with evaluation of a technical system and its being later used for decision making in order to provide complex technical systems with appropriate operation quality. The research object is a real municipal transportation system. The assessment quality of the systems operation is based on the changes of the systems features values. The features describe the operation of the systems operators, controlled technical objects and the environment influence. The assessment and the support the demand quality of the systems operation from the safety, efficiency, economic and reliability point of view is the basic factor of the executed exploitation process. The notion of a system operation quality has been defined, a scheme of an assessment model has been presented and a random process, providing the basis for evaluation of a technical system, has been developed. On the basis of carried out experimental tests there have been distinguished four states of a system operation quality reflecting intervals of values of grades that were characteristic for given time moments. A model of system operation qualitative state changes, based on Markov chain, has been considered in this paper. A system of equations has been determined for a distinguished Markov chain on the basis of which a mathematical model for assessment and control of selected types of transportation systems will be developed.
Źródło:
Journal of KONES; 2014, 21, 3; 251-257
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probabilistic concept of defining the situations possible to occur during operation of floating docks
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/260295.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
floating dock
safety
model
reliability
technical object
semi-Markov process
technical state
Opis:
In this paper possibility to assess safety of floating docks as a result of application of the theory of semi-Markov processes both in the phase of their designing and operating, is outlined. Formal description of the situations which may occur during service of floating docks both those intended for building and repairing the ships, was presented. The following situations were distinguished : normal, complicated, hazardous, emergency and disastrous. A model of changing the distinguished situations was proposed in the form of a semi - Markov process with discrete set of states, and continuous with time. The mentioned situations are values of the process. An operational safety measure for dock was formulated in the form of the probability of the event consisting in occurrence of normal or complicated situation. It was proved that assessment of probability of occurrence of particular situations is possible.
Źródło:
Polish Maritime Research; 2005, S 1; 34-38
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of fuel combustion process in the marine reciprocating engine work space taking into account load and wear of crankshaft-piston assembly and the theory of semi-Markov processes
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259557.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
engine load
marine internal combustion engine
probability
semi-Markov process
crankshaft-piston assembly
Opis:
The article analyses the operation of reciprocal internal combustion engines, with marine engines used as an example. The analysis takes into account types of energy conversion in the work spaces (cylinders) of these engines, loads of their crankshaft-piston assemblies, and types of fuel combustion which can take place in these spaces during engine operation. It is highlighted that the analysed time-dependent loads of marine internal combustion engine crankshaftpiston assemblies are random processes. It is also indicated that the wear of elements of those assemblies resulting from their load should also be considered a random process. A hypothesis is formulated which explains random nature of load and the absence of the theoretically expected detonation combustion in engines supplied with such fuels as Diesel Oil, Marine Diesel Oil, and Heavy Fuel Oil. A model is proposed for fuel combustion in an arbitrary work space of a marine Diesel engine, which has the form of a stochastic four-state process, discrete in states and continuous in time. The model is based on the theory of semi-Markov processes.
Źródło:
Polish Maritime Research; 2016, 3; 50-57
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limiting distribution of the three-state semi-Markov model of technical state transitions of ship power plant machines and its applicability in operational decision-making
Autorzy:
Girtler, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/258958.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
decision
probability
ship power plant machine
semi-Markov process
ship internal combustion engine
Opis:
The article presents the three-state semi-Markov model of the process {W(t): t > 0} of state transitions of a ship power plant machine, with the following interpretation of these states: s1 – state of full serviceability, s2 – state of partial serviceability, and s3 – state of unserviceability. These states are precisely defined for the ship main engine (ME). A hypothesis is proposed which explains the possibility of application of this model to examine models of real state transitions of ship power plant machines. Empirical data concerning ME were used for calculating limiting probabilities for the process {W(t): t > 0}. The applicability of these probabilities in decision making with the assistance of the Bayesian statistical theory is demonstrated. The probabilities were calculated using a procedure included in the computational software MATHEMATICA, taking into consideration the fact that the random variables representing state transition times of the process {W(t): t > 0} have gamma distributions. The usefulness of the Bayesian statistical theory in operational decision-making concerning ship power plants is shown using a decision dendrite which maps ME states and consequences of particular decisions, thus making it possible to choose between the following two decisions: d1 – first perform a relevant preventive service of the engine to restore its state and then perform the commissioned task within the time limit determined by the customer, and d2 – omit the preventive service and start performing the commissioned task.
Źródło:
Polish Maritime Research; 2020, 2; 136-144
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling environment and infrastructure of shipyard transportation systems and processes
Autorzy:
Blokus-Roszkowska, A.
Kołowrocki, K.
Powiązania:
https://bibliotekanauki.pl/articles/2069554.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
ship transportation system
ship operation process
semi-markov process
system in varying operation
Opis:
In the paper an analytical model of port transportation systems environment and infrastructure influence on their operation processes is constructed and presented in an example of shipyard rope transportation systems in Naval Shipyard in Gdynia. A general semi-markov model of a system operation process is proposed and the methods of its parameters statistical identification are presented. Further, the shipyard rope transportation system and the ship rope elevator operation processes are analyzed and their operation states are defined. A preliminary collection of statistical data necessary to the ship transportation systems’ operation processes identification is included.
Źródło:
Journal of Polish Safety and Reliability Association; 2008, 1; 77--84
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Random Failure Rate
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069123.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
reliability
random failure rate
semi-Markov process
random-walk
Poisson process
Furry-Yule process
Opis:
The reliability function defined by a failure rate which is a stochastic process with nonnegative and right continuous trajectories is presented in this paper. The reliability function with an at most countable state space semi-Markov failure rate process is investigated. A theorem concerning of equations for a conditional reliability function with a semi-Markov process as a failure rate is presented in this paper. The solutions of the proper renewal equations allow getting the reliability functions for the finite space semi-Markov random walk, for the Poisson process and for the Furry-Yule process as a failure rate.
Źródło:
Journal of Polish Safety and Reliability Association; 2012, 3, 2; 209--216
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-Markov reliability model of two different units cold standby system
Semi-Markowski model systemu z rezerwą zimną złożony z dwóch różnych podsystemów
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/222851.pdf
Data publikacji:
2017
Wydawca:
Akademia Marynarki Wojennej. Wydział Dowodzenia i Operacji Morskich
Tematy:
reliability
Semi-Markov process
cold standby system
niezawodność
proces semi-Markowa
system z rezerwą zimną
Opis:
A semi-Markov stochastic process is used for solving in a reliability problem in the paper. The problem concerns of two different component cold standby system and a switch. To obtain the reliability characteristic and parameters of the system we construct so called an embedded semi-Markov process in the process describing operation process of the system. In the model the conditional time to failure of the system is represented by a random variable denoting the first passage time from the given state to the specified subset of states. We apply theorems of the Semi-Markov processes theory concerning the conditional reliability functions to calculate the reliability function and mean time to failure of the system. Often an exact reliability function of the system by using Laplace transform is difficult to calculate, frequently impossible. The semi-Markov processes perturbation theory, allows to obtain an approximate reliability function of the system in that case.
Do rozwiązania problemu z zakresu teorii niezawodności został zastosowany proces semi-Markowa. Problem dotyczy tak zwanego systemu z rezerwą zimną, który jest złożony z dwóch różnych podsystemów i przełącznika. Aby uzyskać charakterystyki i parametry niezawodności tego systemu, jako model funkcjonowania systemu konstruujemy proces semi-Markowa — tak zwany proces włożony w inny proces stochastyczny. W naszym modelu czas zdatności systemu jest reprezentowany przez zmienną losową oznaczającą czas pierwszego przejścia z danego stanu do określonego podzbioru stanów. W celu obliczenia funkcji niezawodności i średniego czasu do awarii systemu stosujemy twierdzenia teorii procesów semi-markowskich dotyczące warunkowej funkcji niezawodności. Najczęściej dokładna funkcja niezawodności systemu przy zastosowaniu transformaty Laplace’a jest trudna do wyliczenia. W takim przypadku teoria zaburzonych procesów semi-markowskich pozwala otrzymać przybliżoną funkcję niezawodności systemu.
Źródło:
Zeszyty Naukowe Akademii Marynarki Wojennej; 2017, R. 58 nr 4 (211), 4 (211); 45-60
0860-889X
Pojawia się w:
Zeszyty Naukowe Akademii Marynarki Wojennej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The semi-Markov model of the process of appearance of sea-going ship propupsion system ability and inability states in application to determining the reliablity of these systems
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259071.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
reliability
semi-Markov process
state of ability
state of inability
sea-going ship
ship propulsion system
Opis:
The article presents possible application of the theory of semi-Markov processes in creating the eight-state model of the process of appearance of the propulsion systems ability and inability states on sea-going vessels performing transportation tasks in a relatively long operating time t (t → ∞). The model has been proved to be able to be successfully used for determining the reliability of the abovementioned systems. The probability of faultless operation in time t was assumed the measure of system reliability. Operating situations of sea-going vessels were characterised, with special attention being paid to the fact that the loads of propulsion system components of these vessels are of random nature. These loads lead to damages which for this reason were also considered random events. It was also assumed that the damages provoke the appearance of states of inability of particular ship propulsion system components which means that these states are random events as well. The states of ability of a given ship propulsion system have been assumed to exist when all components of this system are in the state of ability. In case when at least one component is in the state of inability, the entire system is in the state of inability. Conditions were formulated for the reliability model of an arbitrary system to be able to be worked out in the form of the semi-Markov process. The need for the use of technical diagnostics in reliability examination of sea-going ship propulsion systems was indicated. In conclusions, certain qualities of the article were highlighted which are, in author’s opinion, of highest importance in reliability examination of sea-going ship propulsion systems.
Źródło:
Polish Maritime Research; 2013, 4; 18-24
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of damages of tribological associations in crankshaft and piston systems of two-stroke internal combustion engines used as main propulsion in sea-going vessels and proposal of probabilistic description of loads as causes of these damages
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/259908.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
probability
friction associations
crankshaft and piston system
semi-Markov process
marine internal combustion engine
wear
Opis:
The article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of advanced computer technology. It is demonstrated that one of causes of the damages is the lack of research activities oriented on recognising random properties of the loads leading to those damages. A proposal is made for the loads acting at a given time ton tribological associations in crankshaft and piston systems of internal combustion engines used as main engines to be considered as random variables Qt. At the same time the loads examined within a given time interval tr ≤ t ≤ tz would be considered stochastic processes {Q(t): t ≥ 0}. Essential properties of the loads of the abovementioned tribological associations are named and explained by formulating hypotheses which need empirical verification. Interval estimation is proposed for estimating the expected value E(Qt) of the load Qt acting at time t. A relation is indicated between the mechanical load and the thermal load acting on tribological associations in the ship main engine crankshaft and piston system. A suggestion is formulated that a stochastic form of the relation between these types of load is to be searched for, rather than statistic relation, and a proposal is made to measure the intensity (strength) of the stochastic relation using the Czuprow’s convergence coefficient.
Źródło:
Polish Maritime Research; 2015, 2; 44-54
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Degrading systems availability analysis: analytical semi-Markov approach
Autorzy:
Kumar, Varun
Kumar, Girish
Singh, Rajesh Kumar
Soni, Umang
Powiązania:
https://bibliotekanauki.pl/articles/1841831.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
availability
perfect repair
opportunistic maintenance
Embedded Markov Chain (EMC)
Cumulative Density Function (CDF)
Semi-Markov Process (SMP)
Opis:
This paper deals with modeling and analysis of complex mechanical systems that deteriorate with age. As systems age, the questions on their availability and reliability start to surface. The system is believed to suffer from internal stochastic degradation mechanism that is described as a gradual and continuous process of performance deterioration. Therefore, it becomes difficult for maintenance engineer to model such system. Semi-Markov approach is proposed to analyze the degradation of complex mechanical systems. It involves constructing states corresponding to the system functionality status and constructing kernel matrix between the states. The construction of the transition matrix takes the failure rate and repair rate into account. Once the steady-state probability of the embedded Markov chain is computed, one can compute the steady-state solution and finally, the system availability. System models based on perfect repair without opportunistic and with opportunistic maintenance have been developed and the benefits of opportunistic maintenance are quantified in terms of increased system availability. The proposed methodology is demonstrated for a two-stage reciprocating air compressor with intercooler in between, system in series configuration.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 195-208
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Degrading systems availability analysis: analytical semi-Markov approach
Autorzy:
Kumar, Varun
Kumar, Girish
Singh, Rajesh Kumar
Soni, Umang
Powiązania:
https://bibliotekanauki.pl/articles/1841749.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
availability
perfect repair
opportunistic maintenance
embedded Markov chain
EMC
cumulative density function
CDF
semi-Markov process
SMP
Opis:
This paper deals with modeling and analysis of complex mechanical systems that deteriorate with age. As systems age, the questions on their availability and reliability start to surface. The system is believed to suffer from internal stochastic degradation mechanism that is described as a gradual and continuous process of performance deterioration. Therefore, it becomes difficult for maintenance engineer to model such system. Semi-Markov approach is proposed to analyze the degradation of complex mechanical systems. It involves constructing states corresponding to the system functionality status and constructing kernel matrix between the states. The construction of the transition matrix takes the failure rate and repair rate into account. Once the steady-state probability of the embedded Markov chain is computed, one can compute the steady-state solution and finally, the system availability. System models based on perfect repair without opportunistic and with opportunistic maintenance have been developed and the benefits of opportunistic maintenance are quantified in terms of increased system availability. The proposed methodology is demonstrated for a two-stage reciprocating air compressor with intercooler in between, system in series configuration.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 195-208
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of semi-Markov processes for evaluation of diesel engines reliability with regards to diagnostics
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/2073613.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
diagnostics
reliability
semi-Markov process
diesel engine
diagnostic system
diagnostyka
niezawodność
proces semi-Markova
silnik Diesla
system diagnostyczny
Opis:
The paper presents semi-Markov models of technical state transitions for diesel engines, useful for determination of their reliability, as a result of the conducted statistical empirical studies. Interpretation of technical states provided for this sort of engines refers to ship main engines, i.e. engines employed in propulsion systems of sea-going ships. The considerations recognize diesel engine as a diagnosed system (SDN), of which state can be identified by a diagnosing system (SDG). Both of the systems: SDN and SDG compose a diagnostic system (SD). Examples of three-state semi-Markov models were applied to demonstrate that in case of use of proper diagnosing systems (SDG) for identification of technical states of such engines as SDN, by classification of the states to the relevant class of the reference states, it is possible to make use of a Markov model to determine reliability of the engines. For developing a Markov model of state transitions for the engines, there were applied functions of the risk of damage: λ12 that causes transition from state s1 to state s2, and λ13 that causes transition from state s1 to state s3, as well as intensity functions of recovery (restitution): λ21 that causes transition from state s2 to state s1, and λ31 that causes transition from state s3 to state s1.
Źródło:
Journal of Polish CIMEEAC; 2016, 11, 1; 47--53
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problemy oszacowania trwałości i niezawodności silników o zapłonie samoczynnym z zastosowaniem teorii procesów semimarkowskich i diagnostyki
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/134150.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
diagnostyka
niezawodność
proces semimarkowski
silnik o zapłonie samoczynnym
trwałość
diagnostics
reliability
compression ignition engine
semi-Markov process
Opis:
W artykule przestawiono znaczenie trwałości i niezawodności silników o zapłonie samoczynnym w eksploatacji systemów technicznych, w których są zastosowane. Wykazano, że do oszacowania trwałości i niezawodności wspomnianych silników bardziej przydatne są modele opracowane w formie semimarkowskiego procesu zmian stanów technicznych tego rodzaju silników w porównaniu do modeli proponowanych w klasycznej teorii niezawodności. Scharakteryzowano możliwości zastosowania modeli semimarkowskich do badań trwałości i niezawodności tych silników. Uzasadniono konieczność zastosowania diagnostyki technicznej w tego rodzaju badaniach. Przedstawiono przyczyny powodujące niepewność sformułowania właściwej diagnozy ze szczególnym uwzględnieniem czynników wpływających na błędy pomiarów, ale przede wszystkim na niedokładność pomiarów wykonywanych podczas badań diagnostycznych. W podsumowaniu tego artykułu zwrócono uwagę na te walory, które (zdaniem autora) mają najistotniejsze znaczenie w fazie projektowania i eksploatacji silników o zapłonie samoczynnym, szczególnie stosowanych w siłowniach okrętowych jako silniki napędu głównego statku (silniki główne).
Źródło:
Combustion Engines; 2013, 52, 3; 359-366
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of perturbed semi-Markov processes in reliability
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069156.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
semi-markov perturbed process
approximate reliability function
asymptotic
Opis:
The paper is concerned with the application of perturbed semi-Markov (SM) processes in reliability problems. There are two kinds of perturbed SM processes presented in the paper. First of them was defined by Shpak and the second one was introduced by Pavlov and Ushakov. Shpak’s concept of perturbed SM is applied for calculating the approximate reliability function of many tasks operation process and Pavlov and Ushakov concept of that one is used to obtain the approximate reliability function of a repairable cold standby system with a switch.
Źródło:
Journal of Polish Safety and Reliability Association; 2013, 4, 2; 179--188
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Model of Ship Propulsion Systems Operating Process
Model procesu eksploatacji układu napędowego statku
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/360243.pdf
Data publikacji:
2004
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
proces eksploatacji
proces semimarkowski
układ napędowy statku
EXPLO-SHIP 2004
operation process
semi-Markov process
ship propulsion system
Opis:
The paper contains a formal description of ship propulsion systems operation process. The model of the process is presented in the form of two-dimensional stochastic process of which coordinates are semi-Markov processes of the final states set. The former process describes the process of changes in technical states of ship propulsion systems, the latter - the process of changes in their operating states. A monovariate model of ship propulsion systems operation process has also been proposed.
Podano opis formalny procesu eksploatacji układów napędowych statków. Model tego procesu przedstawiono w formie dwuwymiarowego procesu, którego współrzędnymi są procesy semi-Markowa o skończonych zbiorach stanów. Jeden z tych procesów jest procesem zmian stanów technicznych układów napędowych a drugi - procesem zmian ich stanów eksploatacyjnych. Zaproponowano także jednowymiarowy model procesu eksploatacji układów napędowych statków.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2004, 1 (73); 211-220
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-Markov decision process as a safety and reliability model of a sea transport operations
Autorzy:
Grabski, F.
Powiązania:
https://bibliotekanauki.pl/articles/2069650.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
safety reliability
semi-Markov decision process
transport operation
Opis:
A problem of optimization of a sea transport operation in safety and reliability aspect is discussed in the paper. To describe and solve this problem, a semi-Markov decision processes theory is applied. The semi-Markov decision process as a model of the sea transport operation is constructed. An algorithm which Allowi to compute the optimal strategy of the operation in safety and reliability aspect is presented.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 99--104
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Możliwość oszacowania czasu działania dowolnego okrętowego urządzenia energetycznego
Autorzy:
Girtler, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/2073471.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
działanie
obciążenie
proces obciążeń
proces stochastyczny
proces semi-Markowa
urządzenie okrętowe
action
load
load process
stochastic process
semi-Markov process
ship devices
Opis:
W artykule przedstawiono propozycję modelu procesu eksploatacji dowolnego okrętowego urządzenia energetycznego w formie trójstanowego procesu semi-markowskiego {Y(t): t ≥ 0} o zbiorze stanów Z = {z1, z2, z3} i następującej interpretacji elementów tego zbioru: z1 – stan użytkowania urządzenia o stanie pełnej zdatności, (z2) – stan obsługiwania planowego (profilaktycznego) urządzenia będącego w stanie zdatności częściowej, (z3) – stan obsługiwania nieplanowego (wymuszonego uszkodzeniami) urządzenia, które jest wtedy w stanie niezdatności.. Przedstawiono uzasadnienie praktycznej przydatności takiego modelu z uwzględnieniem warunków eksploatacji okrętowych urządzeń energetycznych. Zasygnalizowano, że na bazie opracowanego modelu procesu eksploatacji o trzech stanach może być rozbudowany do tylu stanów eksploatacji ile musi uwzględnić użytkownik wspomnianych urządzeń, aby zapewnić racjonalną ich eksploatację.
Źródło:
Journal of Polish CIMEEAC; 2021, 16, 1; 43--55
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of probabilities defining safety of a sea-going ship during performance of a transportation task in stormy weather conditions
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/2073602.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
reliability
semi-Markov process
diesel engine
propeller
sea-going ship
steering gear
niezawodność
silnik wysokoprężny
śmigło
statek morski
proces semi-Markowa
Opis:
The paper presents the possibility of applying the theory of semi-Markov processes to determine the limiting distribution for the process of changes of technical states being reliability states of the systems of sea-going ships significantly affecting safety of such ships, which include main engine, propeller and steering gear. The distribution concerns the probabilities of occurrence of the said states defined for a long time of ship operation (t → ∞). The considered states are as follows: s0 – full ability state of the systems, i.e.: main engine, propeller and steering gear, s1 – inability state of the main engine, s2 – inability state of the propeller, s3 – inability state of the steering gear. Significance of the systems for safety of the ships at sea was demonstrated herein. General conditions for performing transportation tasks by the ships, with particular regard to stormy conditions, were also here described.
Źródło:
Journal of Polish CIMEEAC; 2017, 12, 1; 21--30
1231-3998
Pojawia się w:
Journal of Polish CIMEEAC
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consequences of maritime critical infrastructure accidents with chemical releases
Autorzy:
Bogalecka, M.
Powiązania:
https://bibliotekanauki.pl/articles/117563.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
critical infrastructure
maritime critical infrastructure
critical infrastructure accident
critical infrastructure accident losses
critical infrastructure accident consequences
maritime transport critical Infrastructure
semi-markov process
chemical releases
Opis:
The probabilistic general model of critical infrastructure accident consequences including three models of the process of the initiating events generated by a critical infrastructure accident, the process of the environment threats and the process of environment degradation is created and adopted to the maritime transport critical infrastructure understood as a ship network operating at the sea waters and then applied to accident consequences modeling, identification and to these consequences optimization and mitigation.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 4; 771-779
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibility of estimating the reliability of diesel engines by applying the theory of semi-Markov processes and making operational decisions by considering reliability of diagnosis on technical state of this sort of combustion engines
Możliwość oszacowania niezawodności silników o zapłonie samoczynnym z zastosowaniem teorii procesów semi-Markowa oraz podejmowania decyzji eksploatacyjnych z uwzględnieniem wiarygodności diagnozy o stanie technicznym tego rodzaju silników spalinowych
Autorzy:
Girtler, J.
Powiązania:
https://bibliotekanauki.pl/articles/134152.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
diagnostics
reliability
semi-Markov process
diesel engine
statistics
diagnosed system
diagnosing system
diagnostic system
osady wewnętrzne we wtryskiwaczach paliwa
silniki z zapłonem samoczynnym
układ wtrysku paliwa
Opis:
The paper presents semi-Markov models of technical state transitions for diesel engines, useful for determining the reliability of engines. A possibility of application of a three-state model with a simplified matrix function, or even a two-state model, to determine reliability of the engines, has been described herein on examples of known from literature semi-Markov models, for the case when appropriate diagnosing systems (SDG) are used to identify the technical condition of the engines considered as diagnosed systems (SDN). A risk function and a renewal (restitution) function have been proposed for developing a two-state model of engine state transitions. An opportunity for considering the reliability of diagnosis for making operational decisions by applying the statistical decision theory, has also been presented. Conditional probability P(si/Ki) is recognized as a measure of reliability of diagnosis.
W artykule przestawiono semimarkowskie modele zmian stanów technicznych silników o zapłonie samoczynnym, przydatne do określenia niezawodności tych silników. Wykazano, na przykładzie znanych z literatury modeli semimarkowskich, że do określenia niezawodności tych silników możliwe jest zastosowanie modelu trójstanowego o uproszczonej macierzy funkcyjnej, a nawet modelu dwustanowego, przy zastosowaniu odpowiednich systemów diagnozujących (SDG) do identyfikacji stanu technicznego wspomnianych silników jako systemów diagnozowanych (SDN). Do opracowania dwustanowego modelu zmian stanów silników zaproponowano wykorzystanie funkcji ryzyka i funkcji intensywności odnowy (restytucji). Przedstawiono także możliwość uwzględnienia wiarygodności diagnozy przy podejmowaniu decyzji eksploatacyjnych w sytuacji zastosowania statystycznej teorii decyzji. Za miarę wiarygodności diagnozy przyjęto prawdopodobieństwo warunkowe P(si/Ki).
Źródło:
Combustion Engines; 2015, 54, 4; 57-66
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On simulation of maintenance costs for water distribution system with fuzzy parameters
O symulowaniu kosztów utrzymania dla systemu dystrybucji wody o parametrach rozmytych
Autorzy:
Romaniuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/1365747.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
water distribution system
maintenance costs
semi-Markov process
Monte Carlo simulations
present value
system dystrybucji wody
koszt konserwacji
proces semi-Markowa
symulacje Monte Carlo
wartość obecna
Opis:
In this paper we propose a model for evaluation of maintenance costs of a water distribution system (WDS). The set of possible states of each connection (i.e. a pipeline in the WDS) is related to various possible degrees of quality of the pipe and types of its malfunctions. The process of transitions between these states forms a semi-Markov process. Using Monte Carlo simulations, the length of services and the times of necessary replacements and repairs of the connections are obtained. These values are then used as an input for estimation of the maintenance costs of the whole WDS. During this step we take into account the concept of present value of money. Contrary to other approaches, instead of a constant yield, a stochastic process (the one-factor Vasicek model) of an interest rate is assumed. Then various simulated measures of reliability and the maintenance costs can be analysed, like an influence of various parameters of the pipes (e.g. intensities of damages) on the final costs of the performed services. They can be crucial in the analysis of risk for various possible decisions. Apart from the crisp approach, the Monte Carlo simulations are also applied, if some of the parameters of the WDS are fuzzified. Therefore uncertainty and experts’ knowledge can be easily incorporated into the proposed procedure of the estimation of the maintenance costs. Observed differences between the crisp and the fuzzy output are highlighted. Simulation algorithms, necessary for both of these approaches, are also provided.
W niniejszym artykule przedstawiono model obliczający koszty utrzymania i konserwacji dla systemu dystrybucji wody (WDS). Zbiór możliwych stanów każdego połączenia (tzn. odcinku rurociągu w WDS) jest zdefiniowany przez różne poziomy jakości rury oraz występujące typy uszkodzeń. Proces przejść pomiędzy tymi stanami jest opisany procesem semi-Markowa. Wykorzystując symulacje Monte Carlo, uzyskano długości okresów obsługi oraz momenty niezbędnych wymian i napraw. Wartości te są następnie wykorzystywane do estymowania kosztów utrzymania całego WDS. W kroku tym brana jest pod uwagę wartość pieniądza w czasie. W przeciwieństwie do innych podejść, zamiast stałej stopy procentowej, założono stochastyczny proces stopy (dany jednowymiarowym modelem Vasicka). Następnie na podstawie przeprowadzonych symulacji wykonano analizę opartą o różne miary niezawodności i obliczone koszty obsługi, np. zbadano wpływ parametrów połączenia (takich jak intensywność uszkodzeń) na ostateczne koszty konserwacji. Analizy tego typu mogą pełnić istotną rolę w ocenie ryzyka dla różnych możliwych do podjęcia decyzji. Poza podejściem typu crisp, zastosowano również symulacje Monte Carlo gdy niektóre z parametrów WDS zostały określone w sposób rozmyty. Dzięki temu można wykorzystać niepewność oraz wiedzę ekspercką w proponowanej metodzie estymacji kosztów obsługi. Zwrócono uwagę na różnice występujące pomiędzy podejściem crisp i rozmytym. Zostały również opisane niezbędne dla obydwu podejść odpowiednie algorytmy symulacyjne.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 4; 514-527
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł

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