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1
Content available Interval-valued intuitionistic fuzzy failure modes and effect analysis of the system failure risk estimation
Nguyen H.
Journal of KONES
|
2017
|
Vol. 24, No. 2
159--166
EN
Among the risk assessment methods, failure modes and effects analysis (FMEA) is a popular, widely used engineering technique in many areas. It can be used to identify and eliminate known or potential failure modes to enhance reliability and safety of complex systems. In practice, risk estimations encounter difficulties connected with shortage of data. In such cases, we have to rely on subjective estimations made by persons with practical knowledge in the field of interest, i.e. experts. However, in some realistic situations, the decision makers might be unable to assign the exact values to the evaluation judgments due to his/her limited knowledge. In other words, there is a certain degree of hesitancy in human cognition and his/her judgment, who may have insufficient knowledge of the problem domain or uncertainty in assigning the evaluation values to the objects considered. In order to deal with ambiguity and uncertainty in the imperfect information, there have been recently proposed many various such theories as fuzzy sets, interval-valued fuzzy sets, type-2 fuzzy sets, hesitant sets, grey sets, rough sets and intuitionistic fuzzy sets. They have drawn more and more attention of scholars and been adopted in many applications This article addresses the Atanassov’s interval-valued intuitionistic fuzzy sets and FMEA methods in the risk estimation of the system failures based on the expert judgments.
2
Content available An application of intuitionistic fuzzy analytic hierarchy process in ship system risk estimation
Nguyen H.
Journal of KONES
|
2016
|
Vol. 23, No. 3
365--372
EN
In this paper, we extend the analytic hierarchy process (AHP) method and the Atanassov’s intuitionistic fuzzy set (IFS) into the intuitionistic fuzzy analytic hierarchy process (IFAHP) with application in ship system risk estimation. In the safety engineering, risk estimation is in practice confronted with difficulties connected with shortage of data. In such cases, we have to rely on subjective estimations made by persons with practical knowledge in the field of interest, i.e. experts. However, in some realistic situations, the decision makers might be reluctant or unable to assign the crisp evaluation values to the comparison judgments due to his/her limited knowledge. In other words, there is a certain degree of hesitancy in human cognition and his judgment. Taking advantages of IFSs in dealing with ambiguity and uncertainty into account, the IFAHP can be used to handle with the subjective preferences of experts, who may have insufficient knowledge of the problem domain or uncertainty in assigning the evaluation values to the objects considered. This paper also develops a new knowledge-based ranking method to derive the priority vector of the hierarchy. An illustrative example of the propulsion risk estimation of container carriers operating on the North Atlantic line is given to show the applicability and effectiveness of the proposed method.
3
Content available remote Strojenie sieci neuronowej niezawodności systemu na podstawie opinii ekspertów
Brandowski A., Nguyen H.
Zeszyty Naukowe Akademii Morskiej w Gdyni
|
2014
|
nr 83
5--20
PL
W artykule przedstawiono metodę strojenia sieci neuronowej, odpowiednią w analizach niezawodności systemów antropotechnicznych, opartą na opiniach ekspertów – praktyków eksploatacji. Przeprowadzono numeryczno-lingwistyczną elicytację tych opinii, które okazały się nieskorelowane i nie nadawały do strojenia sieci. Do przetwarzania danych zastosowano metodę AHP z odpowiednią przyjętą skalą i metodą aproksymacji macierzy ocen. Przeprowadzono analizy korelacji zbiorów otrzymanych danych wejściowych i wyjściowych sieci oraz uchybu metody przetwarzania danych. Wyniki przedstawiono w przykładzie elicytacji i analizy korelacji danych sieci niezawodności systemu napędowego statku morskiego.
EN
The article presents a method for tuning neural network, appropriate in the analysis of the anthrop technical system reliability, based on the opinions of experts – practitioners operation. The numerical-linguistic elicitation of these opinions was carried out, which turned out to be uncorrelated and not suitable for tuning the network. Data processing method was used with the appropriate adopted AHP scale and matrix approximation method evaluations. Correlation analyzes were performed for received input and output data of network and error of data processing method was determined. The results are shown in the example of elicitation and data correlation analyzes for tuning the reliability neural network of the ship propulsion system.
4
Content available Expert judgement-based tuning of the system reliability neural network
Brandowski A., Nguyen H., Frąckowiak W.
Polish Maritime Research
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2014
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nr 1
28--34
EN
The neural network tuning procedure applied to reliability analyses of anthrop technical systems, based on judgements of experts - experienced operating practicians. Numerical and linguistic elicitation of the judgements, analyses of the network input and output data correlation and of the AHP method processing deviation are presented. Example of data elicitation and correlation analysis of a reliability arrangement of the seagoing ship propulsion system are included to the article.
5
Content available Data analysis and processing for the system reliability neural network based on expert judgment
Nguyen H.
Journal of KONES
|
2014
|
Vol. 21, No. 2
235--242
EN
The article presents a data analysis and processing for tuning artificial neural network (ANN) of the anthrop technical system reliability, based on the opinions of experts. In general, the system reliability parameters are functions of operands – physical values – like time to failure, time between failures, duration times of specific reliability or operational states, number of failures in a time interval (event frequencies). These values are easier to be determined by an expert – operator with long year experience – than probabilistic model parameters. It is suggested that they be used in elicitation, for example linguistic estimates of the shares of reliability system elements in the system failure frequency. The numerical – linguistic elicitation of these opinions was carried out, which turned out to be uncorrelated and not suitable for tuning the network. Data processing method was used with the appropriate adopted analytic hierarchy process (AHP) geometric scale and matrix approximation method evaluations (logarithmic least squares method). Correlation analyses were performed for received input and output data of network and error of data processing method was determined. The results are shown in the example of elicitation and data correlation analyses for tuning the reliability neural network of the ship propulsion system.
6
Content available Channel Characterisation and Link Budget of MIMO Configuration in Near Field Magnetic Communication
Nguyen H., Agbinya J. I., Devlin J.
International Journal of Electronics and Telecommunications
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2013
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Vol. 59, No. 3
255-262
EN
Traditional radio communication has gained significantly from using multiple input and multiple output (MIMO) architecture in the system. Many wireless applications, such as wireless LAN and cellular network, have adopted this technology to improve their system performance. However, the effect of MIMO systems has not been investigated in the case of inductive near field short range communications. The purpose of this paper is to explore a new method for increasing the magnetic communication range using MIMO. Three system models includingMISO, SIMO and MIMO are proposed to characterize the number of transmitters and receivers to the link. These models have helped to extend not only the range but also the communication channel in NFMIC.
7
Content available remote Fuzzy–neuron Model of the Ship Propulsion Risk
Brandowski A., Mielewczyk A., Nguyen H., Frackowiak W.
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
|
2011
|
Vol. 5, no. 3
337--343
EN
A prediction model is presented of the ship propulsion risk, i.e. a risk of the consequences of loss of the ship propulsion capability. This is an expert model based on opinions elicited by the ship power plant operators. The risk level depends, among other things, on the reliability state of the ship propulsion sys-tem components. This state is defined by operators in a linguistic form. The formal risk model parameters are determined by means of a neural network. The model may be useful in the ship operation decision processes.
8
Content available remote Metoda estymacji ryzyka napędowego systemów okrętowych
Nguyen H.
Zeszyty Naukowe Akademii Morskiej w Gdyni
|
2010
|
nr 64
89-98
PL
Artykuł przedstawia procedury zastosowania metody AHP w estymacji ryzyka systemów okrętowych. Estymacje parametrów funkcji ryzyka systemów przeprowadza się na podstawie danych ekspertów uzyskanych metodą porównywania parami.
EN
Presented is a method of risk estimation caused by loss of the propulsion function by a seagoing ship. The estimation is fully based on the data obtained from experts and processed using the pair comparison method. An example is given of the propulsion risk estimation of container carriers operating on the North Atlantic line. The example allows to assess effectiveness of the method.
9
Content available Propulsion risk of a seagoing ship prediction based on expert opinions
Brandowski A., Mielewczyk A., Nguyen H., Nguyen H., Frąckowiak W.
Journal of Polish CIMAC
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2010
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Vol. 5, no 2
29-40
EN
A prediction model of the ship propulsion risk is presented, i.e. a risk of the consequences of loss of the ship propulsion capability. This is an expert model based on opinions elicited by the ship power plant operators. The risk level depends, among other things, on the reliability state of the ship propulsion system components. This state is defined by operators in a linguistic form. The formal risk model parameters are determined by means of a neural network. The model may be useful in the ship operation decision processes.
10
Content available remote A fuzzy - neuron model of the ship propulsion risk prediction
Brandowski A., Mielewczyk A., Nguyen H., Frąckowiak W.
Journal of KONBiN
|
2010
|
No. 1 (13)
117-128
EN
A prediction model is presented of the ship propulsion risk, i.e. a risk of the consequences of loss of the ship propulsion capability. This is an expert model based on opinions elicited by the ship power plant operators. The risk level depends, among other things, on the reliability state of the ship propulsion system components. This state is defined by operators in a linguistic form. The formal risk model parameters are determined by means of a neural network.
PL
Przedstawiony został model predykcji ryzyka napędowego statku, czyli ryzyka konsekwencji utraty zdolności do realizacji przezeń funkcji napędu. Jest to model ekspertowy, oparty na opiniach uzyskanych od operatorów siłowni okrętowych. Poziom ryzyka zależy między innymi od stanów niezawodnościowych urządzeń systemu napędowego statku. Stany te wyznaczają operatorzy w formie lingwistycznej. Parametry formalnego modelu ryzyka wyznacza się siecią neuronową.
11
Content available The application of the ahp method in ship system risk estimation
Nguyen H.
Polish Maritime Research
|
2009
|
nr 1
78-82
EN
The article presents procedures of application of the AHP method for estimating risks of ship systems. The estimation of system risk function parameters is done based on the data obtained from experts and processed using the pairwise comparative method.
12
Egzotyka mostów Indochin
Salamak M., Souriyamath K., Nguyen H.
Drogi : lądowe, powietrzne, wodne
|
2008
|
[nr] 12
86--103
PL
W sierpniu 2008 roku zakończył się europejski program Asia-Link, w którym Katedra Dróg i Mostów Politechniki Śląskiej przez trzy lata współpracowała z największymi uczelniami technicznymi w Hochiminh City (dawniej Sajgon) oraz w Vientiane w Laosie. Jednym z jego z głównych celów był transfer europejskiej wiedzy i doświadczeń w zakresie inspekcji i zarządzania mostami.
13
Tereny zieleni w parkach campusowych, na przykładzie parku campusowego Uniwersytetu Nottingham
Nguyen H.
Zeszyty Naukowe. Architektura / Politechnika Śląska
|
2006
|
z. 44
125-129
PL
W artykule autor przedstawił tereny zieleni w Parku Campusowym Uniwersytetu Nottingham w Anglii, jako korzystny przykład planowania przestrzeni uniwersyteckiej. Autor uważa, że studiowanie dobrych przykładów planowania i zarządzania przestrzeniami w campusach uniwersyteckich krajów zachodnioeuropejskich może być doświadczeniem przydatnym przy planowaniu dalszego rozwoju przestrzeni uniwersyteckich w Polsce.
EN
This article introduced the system of green open spaces in the Park Campus of the Nottingham University, England, as a good example of universities' planning. The author suggested, that studying successful examples of planning and management for the universities' campuses in developed countries and their valuable experience would be helpful for the development of higher education space in Poland.
14
Content available remote The neural methods in expert judgment processing.
Brandowski A., Frąckowiak W., Nguyen H.
Zagadnienia Eksploatacji Maszyn
|
2006
|
Vol. 41, nr 3
179-188
EN
In the safety modeling, in view of frequent lack of real data, we have to use the subjective judgments elicited by experts. These judgments may contain various kind of errors. We try to eliminate them in the phase of processing of judgments elicited by a group of experts. The paper discusses the application of neural methods to that processing. Specific features of the neural methods, important for the problem in question are presented. Results are given of the ship voyage duration time judgment processing. Very good results have been obtained. The summary presents a broad analysis of those results and also a more general aspect of the use of neural methods in the expert estimations.
PL
W modelowaniu bezpieczeństwa, wobec częstego przypadku braku danych rzeczywistych, zmuszeni jesteśmy korzystać z subiektywnych sądów ujawnionych przez ekspertów. Sądy te mogą zawierać błędy rozmaitej natury. Staramy się je wyeliminować w fazie przetwarzania sądów wyrażanych przez grupę ekspertów. Referat dotyczy zastosowania metod neuronowych do tego przetwarzania. Przedstawiono istotne w rozważanym przypadku specyficzne cechy metod neuronowych. Pzytoczone zostały wyniki przetwarzania sądów o czasach podróży morskich statku. Uzyskano bardzo dobre wyniki. W podsumowaniu dokonano analizy tych wyników oraz szerszego aspektu zastosowania metod neuronowych w metodach ekspertowych.
15
Content available A simulation model of energy distribution in ship combustion engine
Nguyen H.
Polish Maritime Research
|
2005
|
nr 1
22-26
EN
In the paper a model of energy flow and distribution in ship diesel engine cylinder was presented. This is a model of discrete parameters, being a continuation of the author s research on simulation of energy processing within ship main propulsion engine [2,3]. The model in question makes it possible to calculate energy flow values delivered and transferred during every working cycle of the engine cylinder. Results of application of the model for 6ZA40S Sulzer engine installed on B672 ship were also attached. The results were compared with results of test-stand measurements of the engine, performed at different load levels.
16
Content available remote Simulation model of a ship diesel engine supercharging air cooler
Nguyen H.
Polish Maritime Research
|
2003
|
nr 1
14-19
EN
In the paper a simulation model of heat exchange in supercharging air cooler of ship diesel engine, is presented. The model makes it possible to calculate instantaneous values of heat flow from air to cooling medium, temperature distribution within the cooler as well as temperatures of media at outlet from the cooler. Being a part of a general model of energy transformation in the diesel engine it can function in real time and within the entire range of engine load. The model was verified by comparing the calculation results with the measured data from tests of a real cooler and by assessing correctness of time courses of selected parameters of the cooler.
17
Content available remote A simulation model of heat exchange in the ship diesel engine cylinder - environment system
Nguyen H.
Polish Maritime Research
|
2002
|
Vol. 9, nr 1
9-14
EN
In the paper a model of heat exchange in the diesel engine cylinder - environment system was presented together with its application to 6ZA40S engine. The model, a component of the general model of energy transformation process in the engine, makes it possible to calculate instantaneous values of heat flow through cylinder walls. It can operate in real time mode within the entire range of engine load. The model was verified by comparing the simulation results and data from engine bed test measurements as well as by assessing time course correctness of selected working perameters.
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