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Упит dcterms_subject_txt:Fuzzy sets

162 items

  • Fuzzy expert analysis of the severity of mining machinery failure

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    Mining machinery failure is almost an everyday occurrence. Usually the failures bare certain consequences, which require additional financial costs to repair and restore the system to its operational state. The consequences are viewed through negative and damaging effects a failure has on the machine, health and safety of the employees, work environment, and on the environment. The removal of the consequences of the failure requires additional financial investment, which has a negative impact on the company’s business. In order ...
    Severity of failure, Severity of failure assessment, Mining machinery, Fuzzy sets, Fuzzy logic

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management

  • Fuzzy Model for Risk Assessment of Machinery Failures

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    The main goal of this research was the development of an algorithm for the implementation of negative risk parameters in a synthesis model for a risk level assessment for a specific machine used in the mining industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the ...
    fazi teorija, rizik, otkaz rudarskih mašina
    ... industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the fuzzy sets with ...
    ... industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the fuzzy sets with ...
    ... s for applying fuzzy methodologies, among which the most prominent were the possibilities of applying fuzzy set theory and fuzzy logic to failure diagnoses, the reliability of machines, risk assessments, occupational safety, etc. Chen [8] has suggested applying fuzzy sets and fuzzy arithmetic to system ...

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... assessment. This approach creates an environment for the fuzzy inference engine. Fuzzy sets are in triangular form and these are shown in figure 2, in relation to membership function (μ) and measurement units of A indicators (j = 1 … n). The fuzzy sets of R, M and S indicators have the same form. Values ...
    ... operators/experts distributed 100% of their confidence to five fuzzy sets. Average value of confidences of all operators/experts to specific fuzzy set gives the value of appropriate membership function (μ). Figure 2. Availability fuzzy sets In this way, the membership function of partial indicators ...
    ... describe five linguistic variables i.e. fuzzy sets: poor, adequate, average, good and excellent. Fuzzy sets are in triangular form, and they are presented in relation to membership function (μ) and measurement units of A indicators (j = 1 … 5). Defined A fuzzy set can be written as: - poor = (1/j=1 ...

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station “Bezdan 1”, Serbia

    Dragoljub Bajić, Dušan Polomčić (2014)
    A groundwater control system was designed to lower the water table and allow the pumping sta-tion “Bezdan 1” to be built. Based on a hydrodynamic analysis that suggested three alternative solutions, mul-ticriteria optimization was applied to select the best alternative. The fuzzy analytic hierarchy process methodwas used, based on triangular fuzzy numbers. An assessment of the various factors that influenced the selec-tion of the best alternative, as well as fuzzy optimization calculations, yielded the “weights” of the alternativesand the ...
    groundwater lowering, groundwater management scenario, fuzzy analytic hierarchy process,expert knowledge, triangular fuzzy numbers, linguistic variables
    ... Environmental Earth Science, 71 (6): 2559–2572. VAN LAARHOVEN, P.J.M. & PEDRCYZ, W. 1983. A fuzzy extension of Saaty’s priority theory. Fuzzy Sets and Sy- stems, 11: 229–241. ZADEH, L.A. 1965. Fuzzy Sets, Information and Control, 8 (3): 338–353. ZADEH, L.A. 1975. The concept of a linguistic variable ...
    ... of Operational Research Society, 46: 641–648. BUCKLEY, J.J. 1985. Fuzzy hierarchical analysis. Fuzzy Sets and Systems, 17: 233–247. CHAN, F.T.S. & KUMAR, N. 2007. Global supplier develop- ment considering risk factors using fuzzy extended AHP-based approach. Omega International Journal of Management ...
    ... based on multicriteria Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station 109 Table 2. Ultimate evaluation of alternatives. evaluation and fuzzy sets analysis. Water Resource Ma- nagement, 18: 13–33. KOSKO, B. 1993. Fuzzy thinking: The new science ...

  • Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series

    Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić (2021)
    Underground mining engineers and planners in our country are faced with extremely difficult working conditions and a continuous shortage of money. Production disruptions are frequent and can sometimes last more than a week. During this time, gate road support is additionally exposed to rock stress and the result is its progressive deformation and the loss of functionality of gate roads. In such an environment, it is necessary to develop a low-cost methodology to maintain a gate road support system. ...
    deformacije podgrade, lasersko skeniranje, višekanalna singularna spektralna analiza, prognoza, klasterisanje fuzzy vremenskih serija
    ... Discrimination of EEG Recordings. Stats 2018, 1, 155–168. [CrossRef] 17. Song, Q.; Chissom, B.S. Fuzzy time series and its models. Fuzzy Sets Syst. 1993, 54, 269–277. [CrossRef] 18. Zadeh, L.A. Fuzzy sets. Inform. Control 1965, 8, 338–353. [CrossRef] 19. Zadeh, L.A. The Concept of a Linguistic Variable ...
    ... Modelling fuzzy time series with multiple observations. Int. J. Innov. Comput. Inf. Control 2012, 8, 7415–7426. 21. Chen, S.M. Forecasting enrolments based on fuzzy time series. Fuzzy Sets Syst. 1996, 81, 311–319. [CrossRef] 22. Liang, C.T.; Hsue, C.C.; Ching, C.Y. Using Extracted Fuzzy Rules Based ...
    ... Hence, F(t — 1) — F(t) becomes A;(t—1) — Aj;(t). The algorithm of a fuzzy time series model for multiple observations is composed of the following steps [23]: Energies 2021, 14, 3710 8 of 20 Step 1: define the fuzzy sets for the fuzzy time series. We set the beginning and the end of the universe of ...

  • The Fuzzy–AHP Synthesis Model for Energy Security Assessment of the Serbian Natural Gas Sector

    Aleksandar R. Madžarević, Dejan D. Ivezić, Miloš L. Tanasijević, Marija A. Živković (2020)
    Natural gas is used for the production of almost 20% of total energy today. The natural gas security of the Republic of Serbia is an urgent strategic, political and security issue. Serbia is one of the most vulnerable countries in Southeast Europe, because it only has one supply route. This study is a contribution to efforts to better understand the factors affecting energy security through the implementation of a new methodology based on the fuzzy–AHP synthesis model for measuring ...
    energetska bezbednost, prirodni gas, fazi AHP, AHP višekriterijumska analiza, fazi teorija
    ... ranking problem: A fuzzy set approach. Fuzzy Sets Syst. 1984, 13, 25–37. [CrossRef] 49. Bortolan, G.; Degani, R. A review of some methods for ranking fuzzy subsets. Fuzzy Sets Syst. 1985, 15, 1–19. [CrossRef] 50. Zadeh, L.A. Fuzzy Logic = Computing with words. IEEE Trans. Fuzzy Syst. 1996, 4, 103–111 ...
    ... not have a strictly true/strictly false value. Fuzzy theory represents the concept of the value of truth that ranges from the notion of completely true to the notion of completely false (0–1) [43]. Fuzzy logic, as well as the accompanying theory of fuzzy sets, is tolerant of imprecise data and flexible ...
    ... shape in defining the fuzzy set membership was expressed in linguistic variables where there was no clear and precise difference in the fuzzy conditions, while the function of the triangle shape affiliation was with much more precise linguistic variables [59]. Asymmetric fuzzy sets, inference and layout ...

  • Risk Evaluation: Brief Review and Innovation Model Based on Fuzzy Logic and MCDM

    Stevan Djenadic, Milos Tanasijevic, Predrag Jovancic, Dragan Ignjatovic, Dejan Petrovic, Ugljesa Bugaric (2022)
    The risk assessment of engineering systems represents an important part of the quality of service and dependability. The existing methods for risk evaluation use crisp sets for rating partial indicators’ proposition and their cumulative products as an overall indicator. In this paper, existing FMEA and FMECA methods have been improved using the fuzzy expert system for calculating the risk priority number. The application of fuzzy logic allows the use of linguistic descriptions for risk analysis. In this way, the ...
    rizik, inženjerski sistemi, fazi logika, višekriterijumske metode

  • Development of integrated fuzzy model for mine management optimization

    Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)
    fuzzy logika, višekriterijumsko odlučivanje, ocenjivanje eksperata
    ... ZADEH L. A. (1965) Fuzzy sets, Information and Control, 8(3), 338-353. ZADEH L. A. (1975) The concept of a linguistic variable and its application to pproximate reasoning,, Information sciences, 8, 199—249. Š| CHANG D. Y. (1996) Applications of the extent analysis method on fuzzy AHP, Rur. J. Oper ...
    ... suited for relaying: knowledge and expressing; opinions, the paper tests a fuzzy optimization methodology that uses linguistic variables. Consequently, extent analysis is applied to fuzzy AHP by means of triangular fuzzy numbers to arrive at a decision about the optimal mining; technology. The entire ...
    ... proposed methodology addresses all these issues and fuzzy ogic is its integral part [1'2]. When fuzzy logic is used for multicriteria decision making., the criteria are described by linguistic variables and represented in the form of triangular fuzzy numbers (membership functions: “L, S, D”). On the ...

  • Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović (2022)
    This work presents a model for determining the availability of continuous systems at open pits by applying fuzzy logic and fuzzy inference systems. The applied model was formed by the synthesis of independent partial indicators of availability. The model is based on an expert system for assessing the availability of continuous mining systems. The availability of the system, as a complex state parameter, is decomposed into the partial indicators, reliability, and convenience of maintenance, and the fuzzy compositions, used ...
    системи, континуални систем експоатације, површински коп, рударство, расположивост, фази логика, max–min композиција, min–max композиција

  • A Model for Determining the Dependability of Continuous Subsystems in Coal Mines Using the Fuzzy Logic Approach

    Nikola Stanić, Miljan Gomilanović, Petar Marković, Daniel Krzanović, Aleksandar Doderović, Saša Stepanović (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    fuzzy logic, max-min composition, continuous part of combined system (CCS), open pit, mining, dependability

  • Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine

    Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović (2019)
    Availability is one of the most used terms in maintainability engineering. This concept is used to denote: The quality of service of an engineering system, i.e., machines, weak points’ analysis, asset management, as well as making decisions in the process of life cycle management. Availability is an overall indicator and contains partial indicators that are oriented towards reliability, maintenance, and logistical support. Availability presents a variable value and changes in time and space. Usually, availability is shown as the ...
    raspoloživost, fazi teorija, AHP višekriterijumska analiza, eksperska ocena, buldozer
    ... K.Y. System failure engineering and fuzzy methodology an introductory overview. Fuzzy Sets Syst. 1996, 83, 113–133. [CrossRef] 10. Miodragovic, R.; Tanasijevic, M.; Mileusnic, Z.; Jovancic, P. Effectiveness assessment of agricultural machinery based on fuzzy sets theory. Expert Syst. Appl. 2012, 39 ...
    ... based on the theory of fuzzy sets, has been developed. Theories of fuzzy logic are specifically used for description and proposition of indicators, i.e., their composition in which prevail uncertainty, indefinitely, multiplicity, subjectivity and mutual over-lapping. Fuzzy logic is used as a mathematical ...
    ... availability for corrective maintenance at the equipment type level. Reliab. Eng. Syst. Saf. 2017, 168, 53–69. [CrossRef] 17. Klir, G.J.; Yuan, B. Fuzzy Sets and Fuzzy Logic, Theory and Applications; Prentice Hall: New York, NY, USA, 1995; ISBN 0-13-101171-5. 18. Djuric, R.; Milisavljevic, V. Investigation ...

  • Fuzzy stohastički model izbora sistema otvaranja podzemnog rudnika

    Saša M. Jovanović (2016-05-16)
    Investiciono okruženje skopčano sa rudarskom industrijom je veoma svojstveno kada seuporedi sa okruženjima koje susrećemo u tipičnim proizvodnim industrijama. Neke odkarakterisitka rudarstva, koje su često naznačene kao jedinstvene su: visok intenzitetinvesticija, dugi predproizvodni periodi, visok rizik i neobnovljivost resursa.Investiranje u sistem otvaranja rudnika predstavlja dobar primer ireverzibilneinvesticije. Takva investicija zahteva pažljivu analizu, jer nakon njene realizacije ona sene može nadoknaditi bez značajnog gubitka vrednosti. Očigledno je da izbor sistemaotvaranja podzemnog rudnika pripada strateškom planiranju...
    otkopavanje; otvaranje; mreže i grafovi; fuzzy skupovi; stohastičkiprocesi; indeks konveksnosti; sistemi podrške odlučivanju
    ... New York, (1985). [24] Klein, C. M. (1991). Fuzzy shortest paths, Fuzzy Sets and Systems, 39, 27-41. http://dx.doi.org/10.1016/0165-0114(91)90063-V [25] Kung, J. Y., Chuang, T. N., Lin, C. T. (2006). Decision making on network problem with fuzzy arc lengths , IMACS Multiconference on Computational ...
    ... Ware., H. Li., Option Pricing with Stochastic Volatility Using Fuzzy Sets Theory, Northern Finance Association 2008 Conference Paper, http://www.northernfinance.org/2008/papers/182.pdf [2] Bellman, RE.; Zadeh, LA.: Local and fuzzy logics. In: Dunn JM, Epstein G (eds.) Modern uses of multiple-valued ...
    ... multiple-valued logic. Kluwer, Boston, pp.105–151, pp.158–165 (1977) [3] Bojadziev, G.; Bojadziev, M.: Fuzzy sets and fuzzy logic applications, World Scientific, (1996). [4] Brazil ,M., Lee, D.H, Van Leuven, M., Rubinstein, J.H., Thomas, D.A., and Wormald, N.C.(2003). Optimising declines in underground ...

  • Effectiveness assessment of agricultural machinery based on fuzzy sets theory

    Miodragović Rajko, Tanasijević Miloš, Mileusnić Zoran, Jovančić Predrag (2012)

  • Quantification of Uncertainty in Mining Project Related to Metal Price Using Mean Reversion Process and Interval Type-2 Fuzzy Sets Theory

    Gligorić Zoran, Beljić Čedomir, Gluščević Branko (2013)

  • Machine Learning and Deep Neural Network-Based Lemmatization and Morphosyntactic Tagging for Serbian

    Ranka Stanković, Branislava Šandrih, Cvetana Krstev, Miloš Utvić, Mihailo Škorić (2020)
    The training of new tagger models for Serbian is primarily motivated by the enhancement of the existing tagset with the grammatical category of a gender. The harmonization of resources that were manually annotated within different projects over a long period of time was an important task, enabled by the development of tools that support partial automation. The supporting tools take into account different taggers and tagsets. This paper focuses on TreeTagger and spaCy taggers, and the annotation schema alignment ...
    Part-of-Speech tagging, lemmatization, corpus, evaluation, Serbian, morphological dictionary
    ... PoS-tagging with SerSpaCy tagger on different test sets and for different PoS-tags Figure 5: Results of PoS-tagging with TT19 tagger on different test sets and for different PoS-tags Figure 6: Results of PoS-tagging with TT11 tagger on different test sets and for different PoS-tags taggers as well as ...
    ... Intera respectively. Each of the subsets was split into training, development and test sets (80%:10%:10%). In Table 4 the distributions of number of sentences, tokens and words per training, devel- opment and test sets are given. Using the CLI train command, we trained five different models. Each model ...
    ... performance of both tag- Figure 1: Part-of-Speech tagging accuracy per token on test sets, for each of trained models gers drops significantly when tagging unknown text. Figure 2: nPoS-tagging accuracy per token on test sets Comparison of lemmatization precision of the old and new TreeTagger models is ...

  • Development and Evaluation of Three Named Entity Recognition Systems for Serbian - The Case of Personal Names

    Branislava Šandrih, Cvetana Krstev, Ranka Stanković (2019)
    In this paper we present a rule- and lexicon-based system for the recognition of Named Entities (NE) in Serbian news paper texts that was used to prepare a gold standard annotated with personal names. It was further used to prepare training sets for four different levels of annota tion, which were further used to train two Named Entity Recognition (NER) sys tems: Stanford and spaCy. All obtained models, together with a rule- and lexicon based system were evaluated on ...
    NER, Named Entity Recognition Systems, Serbian, Personal Names
    ... num- ber of personal names in our test sets). Jiang et al. (2016) compared 4 NER systems, two of which were STANFORD NER and SPACY NER, for English. Their test set consisting of Wiki articles contained approximately the same number of personal names as our both sets – around 900. Their results were for ...
    ... Entities (NE) in Serbian news- paper texts that was used to prepare a gold standard annotated with personal names. It was further used to prepare training sets for four different levels of annota- tion, which were further used to train two Named Entity Recognition (NER) sys- tems: Stanford and spaCy. All obtained ...
    ... runs the devel- opment of SRPNER continued, as well as the en- hancement of e-dictionaries of Serbian. 3 Training Different NER Systems 3.1 Training Sets The gold standard GOLDPERS contains 9, 046 sentences, each one enclosed in ... tag. Named entities in sentences are annotated using tags ...

  • Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic

    Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković (2020)
    Artificial lift methods have applications in oil wells where oil production is no longer possible due to natural reservoir energy, so this necessary energy is added by introducing lift methods. In order to achieve optimum production, the selection of an artificial lift method is very important. This paper uses fuzzy logic as a mathematical and conceptual model for selection of the optimal artificial lift method. The outcome or IF-THEN rules, as the central part of the model, is based ...
    mehaničke metode, proizvodnja nafte, fazi logika, donošenje odluka, optimizacija
    ... defined linguistic variables (i.e., fuzzy sets) are: very low, low, moderate, high, and very high. The expert assessment consists of linguistic variables and the extent to which they apply to the observed well. Figure 2. Fuzzy sets. In dependence of μ, fuzzy number (FN) can be presented in form ...
    ... j = 1, 2; μ = 0 for j = 3, ..., 10. Other fuzzy sets can be written as: low = (0/1, 0/2, 1/3, 1/4, 0.33/5, 0/6, 0/7, 0/8, 0/9, 0/10) moderate = (0/1, 0/2, 0/3, 0.5/4, 1/5, 1/6, 0.5/7, 0/8, 0/9, 0/10) Figure 2. Fuzzy sets. In dependence of µ, fuzzy number (FN) can be presented in form (1): FN ...
    ... on 26 March 2020). 17. Klir, G.J.; Yuan, B. Fuzzy Sets and Fuzzy Logic: Theory and Applications. J. Chem. Inf. Comput. Sci. 1996, 36, 619. Energies 2020, 13, 1758 15 of 15 18. Wang, J.; Yang, J.B.; Sen, P. Safety analysis and synthesis using fuzzy sets and evidential reasoning. Reliab. Eng. Syst ...

  • Dvodimenzionalna geometrijska morfometrija prvih gornjih molara hominina sa teritorije Srbije - taksonomska i metodološka analiza

    Predrag N. Radović (2022)
    Primarni cilj ove studije tiče se taksonomske identifikacije fosilnih prvih gornjih molara (M1) hominina pronađenih u Srbiji, primenom metoda dvodimenzionalne (2D) geometrijske morfometrije. U prvoj (metodološkoj) fazi istraživanja ispitana je efikasnost 16 različitih pristupa (geometrijskih modela) u klasifikaciji M1 neandertalaca i anatomski modernog čoveka. Modeli su testirani na dva seta okluzalnih projekcija krunica (n = 34 i n = 64) dobijenih orijentisanjem digitalnih 3D modela u virtuelnom okruženju ili fotografisanjem fizičkih primeraka zuba. Prilikom testiranja primenjena je klasifikacija zasnovana ...
    2D geometrijska morfometrija, prvi gornji molar (M1), taksonomska identifikacija, neandertalci, anatomski moderni ljudi, Pešturina, Velika Balanica, Srbija