Претрага
2635 items
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A Fuzzy Expert Model for Availability Evaluation
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 ...... Liebherr in terms of R, with grades "good" in extent of 40% and “average” in extent of 60%; M as "average" in extent of 100% and S as "adequate" in extent of 100%; machine Dressta as "average" in all terms and Caterpillar as "good" in terms of R and S and "excellent" in term of M. This can be written ...
... 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 ...
... Industry of Serbia Kostolac, Serbia radisa.duric@te-ko.rs Predrag Jovancic Faculty of Mining and Geology University of Belgrade Belgrade, Serbia predrag.jovancic@rgf.bg.ac.rs Abstract—Each technical system within itself carries the great potential danger of possible occurrence of failure ...Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić. "A Fuzzy Expert Model for Availability Evaluation" in Proceedings of the 2019 20th International Carpathian Control Conference (ICCC), AGH University of Science and Technology, Kraków - Wieliczka, Poland (2019)
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Effectiveness Analysis of Different Bucket-wheel Excavators
Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić. "Effectiveness Analysis of Different Bucket-wheel Excavators" in 8th International Conference Mining and Environmental Protection, Sokobanja, 22-25 September 2021, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2021)
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Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian
Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek. "Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian" in Language and Text: Data, models, information and applications, John Benjamins Publishing Company (2021). https://doi.org/10.1075/cilt.356.04ruj
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Multiple-Criteria Decision-Making in Mine Development Planning
Sanja Bajić (2023)The Borska Reka ore deposit is an experimental location where developed methodologies have been applied. It is the largest ore body within the Bor mining complex, which has been the subject of numerous studies and analyses for more than three decades. The paper focuses on the application of FAHP and the VIKOR method to address ranking of alternatives and select the optimal mining method by means of fuzzy multicriteria optimization.Sanja Bajić. "Multiple-Criteria Decision-Making in Mine Development Planning" in Proceedings of the 5th International Underground Excavations Symposium, 5-6-7 June 2023, Istanbul, Topkapi : Dinç Ofset Mat. Rek. San. ve Tic. Ltd. Şti. (2023)
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Automatic construction of a morphological dictionary of multi-word units
The development of a comprehensive morphological dictionary of multi-word units for Serbian is a very demanding task, due to the complexity of Serbian morphology. Manual production of such a dictionary proved to be extremely time-consuming. In this paper we present a procedure that automatically produces dictionary lemmas for a given list of multi-word units. To accomplish this task the procedure relies on data in e-dictionaries of Serbian simple words, which are already well developed. We also offer an evaluation ...electronic dictionary, Serbian, morphology, inflection, multiwordn units, noun phrases, query expansion... case of toponyms all cases of failure are due to the fact that components of toponyms were not simple words in Serbian (e.g. Feja in Kriva Feja). The lowest rank of a successful result was 6 for common nouns, and 2 for toponyms. Table 5. Evaluation of the strategy for nouns applied on a list of MWU common ...
... gives percentages of successfully produced noun and adjectives en- tries (case a), partially successful results (case b) and failures (case c), and also indicates the rank of these results (rank 0 means no solution offered). A failure means that either no solution was offered or none of the solutions was ...
... Duško Vitas3, and Miloš Utvić1 1 Faculty of Philology, University of Belgrade 2 Faculty of Mining and Geology, University of Belgrade 3 Faculty of Mathematics, University of Belgrade Abstract. The development of a comprehensive morphological dictio- nary of multi-word units for Serbian is a very demanding ...Cvetana Krstev, Ranka Stanković, Ivan Obradović, Duško Vitas, Miloš Utvić. "Automatic construction of a morphological dictionary of multi-word units" in Lecture Notes in Computer Science 6233, Advances in Natural Language Processing, Proceedings of the 7thInternational Conference on NLP, IceTAL 2010, Reykjavik, Iceland, August 2010, Springer (2010): 226-237. https://doi.org/10.1007/978-3-642-14770-8_26
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Numerical modeling of Selanac debris flow propagation using SPH code
The Selanac debris flow is a very huge event triggered after extreme rainfall caused by Cyclone Tamara activity in the Republic of Serbia in May 2014. The Selanac case study was already modelling in different programs using Voellmy rheology assumptions like RAMMS software. In this paper research are focusing particularly on the process of debris flowing from initiation zone to main deposition area using Geoflow SPH two-phase model considering frictional rheology law. Main rheological parameters are back-calculated using also ...... first-failure flow type landslides especially across the Western Serbia. Most of these occurrences were defined as granular flows, which were not a typical landslide mechanism for this area. One such example is Selanac debris flow, which stands among the largest occurrence of this type of landslides ...
... discussed by Pastor et al. (2009) considering: A. balance of mass of the mixture—propagating along the slope and increasing due to bed entrainment—combined to the balance of linear momentum of pore water, B. the balance of linear momentum of the mixture, C. a kinetic relation between the defor ...
... mechanical behavior of the mixture can be described by a system of differential equations governing the dynamics of each of the phases as well as the coupling among them (Pastor et al, 2008). SPH (Smoothed Particle Hydrodynamics) is a mesh- less approach, widely used in different fields of research, and ...Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi . "Numerical modeling of Selanac debris flow propagation using SPH code" in SCG-XIII International Symposium on Landslides. Cartagena, Colombia- February 22-26, 2021, International Society for Soil Mechanics And Geotechnical Engineering (2021)
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Production of morphological dictionaries of multi-word units using a multipurpose tool
The development of a comprehensive morphological dictionary of multi-word units for Serbian is a very demanding task, due to the complexity of Serbian morphology. Manual production of such a dictionary proved to be extremely time-consuming. In this paper we present a procedure that automatically produces dictionary lemmas for a given list of multi-word units. To accomplish this task the procedure relies on data in e-dictionaries of Serbian simple words, which are already well developed. We also offer an evaluation ...electronic dictionary, Serbian, morphology, inflection, multi-word units, noun phrases, query expansion... amounts to as much as 38.61%. All of the failures in the case of toponyms resulted from the absence of one or more of its components from dictionaries of simple words in Serbian (e.g. in Gornji Tavankut, Tavankut is not used independently), which is in line with failure causes in the experiment with ...
... words. In a much smaller number of Fig. 7. Results obtained on the second set of test data (in%) cases (20%) the incorrect solution resulted from the system’s failure to cover a specific MWU structure. With the second set of test data (nouns collected from various sources) we proceeded as follows. ...
... functionality of LeXimir, and makes use of our comprehensive e- dictionaries of Serbian simple words. We present an evaluation of the performance of this functionality, and hence of our procedure, obtained from experiments on two types of data. Finally, we discuss some further possible applications of our procedure ...Ranka Stanković, Ivan Obradović, Cvetana Krstev, Duško Vitas. "Production of morphological dictionaries of multi-word units using a multipurpose tool" in Proceedings of the Computational Linguistics-Applications Conference, October 2011, Jachranka, Poland, Jachranka, Poland : PTI - Polish Information Processing Society (2011)
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Primena termografije u rudarstvu
Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragan Ignjatović, Dragutin Jovković, Filip Miletić (2019)Danas, gotovo da nema oblasti u nauci i tehnici u kojoj se Infracrvena termografija ne primenjuje kao metoda za lociranje i praćenje zagrejanih objekata ili tela, beskontaktnu procenu temperature površina, i nedestruktivno ispitivanje materijala. U radu su prikazane mogućnosti i perspektive primene ove metode u oblasti rudarstva.... N., Application of infrared thermography and geophysical methods for defect detection in architectural structures, Engineering Failure Analysis, Vol. 12, pp. 875-892, 2005. [5] Tomic Lj., Kovacevic A., Damnjanovic V., Osmokrovic P., Probability density function estimation of a temperature field ...
... Inspections of Mechanical Components. URL:https://www.infratec-infrared.com/thermography/industries- applications/maintenance-of-mechanical-assemblies/ [10] Zhai X., Wu S., Wnag K., Drebenstedt C., Zhao J., Environmental influences and extinguish technology of spontaneous combustion of coal gangue ...
... радовима запослених доступним у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository ...Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragan Ignjatović, Dragutin Jovković, Filip Miletić. "Primena termografije u rudarstvu" in IX Međunarodna konferencija UGALJ 2019, Zlatibor, Srbija, 23-26. oktobar 2019., Jugoslovenski komitet za površinsku eksploataciju (2019)
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Models of Determining the Parameters of Rock Mass Oscillation Equation with Experimental and Mass Blastings
... as Failure Precursor Phenomenon for Seismic Activity Monitoring, Fracture, Fatigue, Failure, and Damage Evolution; Springer: Cham, Switzerland; Heidelberg, Germany; New York, NY, USA; Dordrecht, The Netherlands; London, UK, 2015; Volume 5, pp. 221–229. 2. Kahriman, A. Analysis of Parameters of Ground ...
... Parameters through the Application of Quotient of Products of the Same Number of Reduced Distances and Oscillation Velocities According to this model, determination of the parameter n is based on the quotient of the product of equal number of experimental data of the rock mass oscillation velocity v ...
... detonation of explosive materials is followed by release of a large amount of energy. Whereby, a greater part of energy is used for rock destruction, and part of energy, in the form of seismic wave, is lost in the rock mass causing rock mass oscillation. Investigations of the character and behavior of the pattern ...Suzana Lutovac, Branko Gluščević, Rade Tokalić, Jelena Majstorović, Čedomir Beljić. "Models of Determining the Parameters of Rock Mass Oscillation Equation with Experimental and Mass Blastings" in Minerals, Basel : MDPI AG, Basel, Switzerland (2018). https://doi.org/10.3390/min8020070
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Mogućnost infracrvene termografije pri detekciji štetnih gasova
Curenje pojedinih gasova je opasnost koja može da izazove velike nezgode. Često je praćeno požarima i eksplozijama koji za posledicu mogu da imaju kako ljudske povrede, tako i štetan uticaj na ekologiju i ekonomiju. Da bi se izbegle takve situacije, preventivna inspekcija je od presudne važnosti. Curenje većine gasova se ne može uočiti golim okom a za otkrivanje i procenu stepena curenja može se koristiti tehnologija toplotnog snimanja (infracrvena termografija). U datom radu predstavljene su mogućnosti i ograničenja primene ...Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković. "Mogućnost infracrvene termografije pri detekciji štetnih gasova" in VIII Memorijalni naučni skup iz zaštite životne sredine "Docent dr Milena Dalmacija", Novi Sad, 01-02. april 2021., Prirodno-matematički fakultet (2021)
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A business intelligence approach to mine safety management
Ljiljana Kolonja, Ranka Stanković, Ivan Obradović, Olivera Kitanović, Dejan Stevanović, Marija Radojičić (2016)... n and analysis. The number of injuries, which represents a measure, is the central value of the cube that is analyzed. In our system, dimensions that are structural attributes of the cube, grouping data of similar category, are: type of injury, body part, severity of injury, worker’s age and q ...
... most important parts are the classification of external causes of injury, injury severity assessment and specification of part or parts of the body that were injured. 3.2 Methodology for data analysis Online analytical processing is a capability of management, decision support and executive ...
... quarter of the year, then by month, by date and finally selected injury levels. Figure 8 presents the number of injuries by quarter of the year, then by month, with severity of the injury, in tabular and graphical format, thus combining the time dimension (with its hierarchy) and injury severity. ...Ljiljana Kolonja, Ranka Stanković, Ivan Obradović, Olivera Kitanović, Dejan Stevanović, Marija Radojičić . "A business intelligence approach to mine safety management" in 13th International Symposium Continuous Surface Mining, Beograd : Yugoslav Opencast Mining Committee (2016)
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Regional Slope Stability Analysis in Landslide Hazard Assessment Context, North Macedonia Example
Miloš Marjanović, Biljana Abolmasov, Igor Peshevski, James Reeves, Irena Georgievska. "Regional Slope Stability Analysis in Landslide Hazard Assessment Context, North Macedonia Example" in Understanding and Reducing Landslide Disaster Risk, Springer International Publishing (2020). https://doi.org/10.1007/978-3-030-60227-7_29
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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 ...... prioritization of failures in a system failure mode, effects and criticality analysis. Reliab. Eng. Syst. Saf. 1995, 50, 203–213. [CrossRef] 29. Petrović, D.V.; Tanasijević, M.; Milić, V.; Lilić, N.; Stojadinović, S.; Svrkota, I. Risk assessment model of mining equipment failure based on fuzzy ...
... shows the conceptual model of an expert system for optimized selection of an artificial lift method evaluation on the base of fuzzy interferences of the input data. Energies 2020, 13, 1758 5 of 15 Energies 2020, 13, x 5 of 15 Figure 1. The schematic diagram of the fuzzy model. Parameters ...
... center of gravity moves to the right. When the parameters are reduced, the center of gravity moves to the left of the diagram. The uneven shift of the focus to the left side of the diagram is due to a considerable number of parameters being at the limit values (1 or 10). Figure 7. Center of mass ...Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković. "Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic" in Energies, MDPI AG (2020)
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Метода променљивих околина за решавање проблема p-центра са поузданом мрежом
У овом раду је разматран проблем p-центра са поузданом мрежом (енгл. Reliable p-center facility location problem - RpCFLP). Решавање проблема подразумева иницијално успостављање p ресурса и алокације корисника, као и накнадну реалокацију корисника у складу са новонасталим сценаријима који садрже информације о онеспособљеним ресурсима и осталим измењеним улазним подацима. За решавање посматраног проблема предложена је метахеуристика заснована на итеративној варијанти основне методе променљивих околина (енгл. Iterated basic variable neighborhood search - IBVNS). Резултати тестирања предложене метахеуристике указују на њену ...Јована Рађеновић, Стефан Мишковић, Оливера Станчић. "Метода променљивих околина за решавање проблема p-центра са поузданом мрежом" in 50. Међународни симпозијум о операционим истраживањима SYM-OP-IS, Тара, Србија, 18-21.9.2023, Београд : Медија центар „Одбрана” (2023)
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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 ...Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić. "Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine" in SSRN Electronic Journal, Elsevier BV (2021). https://doi.org/10.2139/ssrn.3945617
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Uporedna analiza stabilnosti završnih kosina površinskog kopa „Veliki Krivelj“
Mihajlo Topalović (2023)Površinski kop „Veliki Krivelj“ nalazi se u blizina grada Bora i u neposrednoj blizini sela Krivelj. Od 2018. godine je u vlasništvu kineske kompanije „Zijin“ koja ima udeo od 63% vlasništva celokupnog RTB-a Bor. Na površinskom kopu obavlja se masovna eksploatacija rude bakra opremom visokog kapaciteta. Za bušenje se koriste bušilice prečnika od 250 do 310 mm, a za utovar minirane rude i jalovine bageri čija je zapremina kašike 15 m3 i 22 m3. Za površinski kop „Veliki Krivelj“ ...Mihajlo Topalović. Uporedna analiza stabilnosti završnih kosina površinskog kopa „Veliki Krivelj“, 2023
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Hydrogeochemical distribution of Ca and Mg in groundwater in Serbia
Petar Papić, Jovana Milosavljević, Marina Ćuk, Rastko Petrović . "Hydrogeochemical distribution of Ca and Mg in groundwater in Serbia" in Groundwater: Occurrence and Significance for Human Health, CRC Press, Balkema - Taylor & Francis Group (2014)
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Frequency and Length of Syllables in Serbian
Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová (2019)Basic analyses of several properties of syllables (the rank-frequency distribution, the distribution of length, and the relation between length and frequency) in Serbian is presented. The syllabification algorithm used combines the maximum onset principle and the sonority hierarchy. Results indicate that syllables behave similarly to words as far as mathematical models are concerned, but values of parameters in models for syllables are quite different from those for words.... Treiman, R., Elzinga, D. (2013b). Syllabification of American English: Evidence from a large-scale experiment. Part II. Journal of Quantitative Linguistics 20, 75-93. Ferrer-i-Cancho, R., Hernández-Fernández, A. (2013). The failure of the law of brevity in two New World primates. Statistical caveats ...
... investigate many properties of syllables. In this paper we limit ourselves to analyses of three aspects: 1) the rank-frequency distribution, 2) the distribution of length, and 3) the relation between length and frequency. The goodness-of-fit of a model is evaluated in terms of the discrepancy coefficient ...
... lack of its precise definition8 (cf. also Crystal, 2008, pp. 467-468; 1 Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, 21101 Novi Sad, Serbia, and Faculty of Mining and Geology, University of Belgrade, Đušina ...Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová. "Frequency and Length of Syllables in Serbian" in Glottometrics (2019)
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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... results. Good consistency, both in terms of strength and failure Energies 2021, 14, 3710. https://doi.org/10.3390/en14123710 https:/ /www.mdpi.com/journal/energies Energies 2021, 14, 3710 2 of 20 mode, was provided when a comparison of these three types of information was done [1]. Danial Jahed ...
... where an analytic method, along with existing data from physical model tests, was applied to acquire results. Good consistency, both in terms of strength and failure Energies 2021, 14, 3710. https://doi.org/10.3390/en14123710 https://www.mdpi.com/journal/energies https://www.mdpi.com/journal/energies ...
... vector of the marker m in the current support configuration. → v (t− 1)—the position vector of the marker m in the previous support configuration. → u (t)—the vector of displacement. N—time of monitoring. Figure 2. Change of the marker position over time. In the xz-coordinate plane, the position of the ...Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić. "Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series" in Energies, MDPI (2021). https://doi.org/https://doi.org/10.3390/en14123710
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An intelligent hybrid system for surface coal mine safety analysis
Nikola Lilić, Ivan Obradović, Aleksandar Cvjetić. "An intelligent hybrid system for surface coal mine safety analysis" in Engineering Applications of Artificial Intelligence (2010)