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91 items

MultiCriteria FuzzyStochastic Diffusion Model of Groundwater Control System Selection
When considering data and parameters in hydrogeology, there are often questions of uncertainty, vagueness, and imprecision in terms of the quantity of spatial distribution. To overcome such problems, certain data may be subjectively expressed in the form of expert judgment, whereby a heuristic approach and the use of fuzzy logic are required. In this way, decisionmaking criteria relating to an optimal groundwater control system do not always have a numerical value. Groundwater control scenarios (alternatives) are identified through hydrodynamic ...expert judgment, linguistic variables, fuzzy dynamic TOPSIS, hydrogeology, groundwater control system, opencast mine, geometric Brownian motionDušan Polomčić, Zoran Gligorić, Dragoljub Bajić, Miloš Gligorić, Milanka Negovanović. "MultiCriteria FuzzyStochastic Diffusion Model of Groundwater Control System Selection" in Symmetry, MDPI AG (2019). https://doi.org/10.3390/sym11050705

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 station “Bezdan 1” to be built. Based on a hydrodynamic analysis that suggested three alternative solutions, multicriteria 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 selection 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... natural way, by linguistic vari ables, such that fuzzy logic is “computing with words” (ZADEH 1965; ZADEH 1975). As indicated above, the basic unit that represents knowledge in fuzzy logic is a linguistic variable, with its linguistic values that make up fuzzy sets. Combinations of variables and their values ...
... natural language, and not numbers. Apart from their symbolic linguistic form, linguistic vari ables also have a quantified analytical formmember ship function, such that they are of a dual nature. This dual identity makes linguistic variables suitable for qualitativesymbolic and quantitativenumerical ...
... words: groundwater lowering, groundwater management scenario, fuzzy analytic hierarchy process, expert knowledge, triangular fuzzy numbers, linguistic variables. Апстракт. За обарање нивоа подземних вода како би се изградила црпна станица „Бездан 1” пројектован је систем одбране од подземних вода. На ...Dragoljub Bajić, Dušan Polomčić. "Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station “Bezdan 1”, Serbia" in Geološki anali Balkanskoga poluostrva, Belgrade : University of Belgrade  Faculty of mining and geology (2014). https://doi.org/10.2298/GABP1475103B

Stability, bifurcations, and dynamics of global variables of a system of bursting neurons
Franović Igor, Todorović Kristina, Vasović Nebojša, Burić Nikola. "Stability, bifurcations, and dynamics of global variables of a system of bursting neurons" in Chaos 21 no. 3, Koledž Park:American Institute of Physics (2011): 0331091

Примена ауторегресионих модела за потребе краткорочних прогноза истицања карстних врела
Вељко Мариновић, Весна Ристић Вакањац, Саша Милановић, Љиљана Васић, Бранислав Петровић, Душан Поломчић, Радисав Голубовић (2023)Модел вишеструке линеарне регресије је најчешће примењивани модел за симулације, односно прогнозе одговарајућих случајно променљивих величина. Као најједноставнији модели примењују се ауторегресиони (АР) модели који симулирају истицање карстних врела на основу издашности врела регистрованих претходних дана. АР модели примењени су на примерима Великог врела за шестогодишње периоде осматрања, односно врела Бање и Гостиљског врела за десетогодишње периоде осматрања. Укључивањем више независних величина, коефицијенти корелације безначајно расту, те је препорука да се максимално 3 независне променљиве укључе у симулациони модел. ...Вељко Мариновић, Весна Ристић Вакањац, Саша Милановић, Љиљана Васић, Бранислав Петровић, Душан Поломчић, Радисав Голубовић. "Примена ауторегресионих модела за потребе краткорочних прогноза истицања карстних врела" in 50. симпозијум о операционим истраживањима  SYMOPIS 2023, Тара, 18–21. септембар 2023., Београд : Медија центар „Одбрана” (2023)

Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic
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 композицијаMiljan Gomilanović, Miloš Tanasijević, Saša Stepanović. "Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic" in Energies, MDPI AG (2022). https://doi.org/10.3390/en15186786

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 ...... analyzed indicator. Regarding the number of linguistic variables, it can be found that seven is the maximal number of rationally recognizable expressions that human can simultaneously identify [8]. Therefore, the accepted value of linguistic variables is five (Fig. 2) for representing A and its ...
... Proposition The first step in the making of expert model for A assessment is describing linguistic variables related to A itself and to R, M and S. It is necessary to describe five linguistic variables i.e. fuzzy sets: poor, adequate, average, good and excellent. Fuzzy sets are in triangular form ...
... Questionnaire have multiple choices for evaluation (linguistic variables) of each indicator  R, M and S. Analysts evaluated affiliation to specific grade with 100%, or distributed their evaluation to several grades (given as linguistic variables) [4]. TABLE I. QUESTIONNAIRE FOR ASSESSMENT OF ...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)

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 IFTHEN rules, as the central part of the model, is based ...... This is a procedure for representing a statement that includes linguistic variables based on available information about the considered engineering system [17]. A definition of structure and interdependence of linguistic variables is carried out in a coordinate system of membership function (µ), ...
... observed phenomena. Regarding the number of linguistic variables, seven has been found to be the maximal number of rationally recognizable expressions that a human can simultaneously identify [18]. Therefore, the accepted value of linguistic variables for representing M performances is five (Figure ...
... (Figure 2). The five necessary 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. Energies 2020, 13, x 6 of 15 Maximum operating temperature ...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)

Critical disorder and critical magnetic field of the nonequilibrium athermal randomfield Ising model in thin systems
Svetislav Mijatović, Dragutin Jovković, Sanja Janićević, Đorđe Spasojević. "Critical disorder and critical magnetic field of the nonequilibrium athermal randomfield Ising model in thin systems" in Physical Review E, American Physical Society (APS) (2019). https://doi.org/10.1103/PhysRevE.100.032113

Hydrochemical changes and groundwater grouping data by multivariate statistical methods within one karst system: recharge–discharge zone (Eastern Serbia case study)
Ljiljana Vasić, Dragana Živojinović, Vladana RajakovićOgnjanović. "Hydrochemical changes and groundwater grouping data by multivariate statistical methods within one karst system: recharge–discharge zone (Eastern Serbia case study)" in Carbonates and Evaporites, Springer Science and Business Media LLC (2020). https://doi.org/10.1007/s13146019005486

The number of unimodular roots of some reciprocal polynomials
Dragan Stankov (2020)We introduce a sequence P2n of monic reciprocal polynomials with integer coefficients having the central coefficients fixed. We prove that the ratio between number of nonunimodular roots of P2n and its degree d has a limit when d tends to infinity. We present an algorithm for calculation the limit and a numerical method for its approximation. If P2n is the sum of a fixed number of monomials we determine the central coefficients such that the ratio has the minimal limit. ...Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, SchinzelZassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomialsDragan Stankov. "The number of unimodular roots of some reciprocal polynomials" in Cmptes rendus mathematique (2020). https://doi.org/10.5802/crmath.28

Fuzzy expert analysis of the severity of mining machinery failure
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 ...Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković. "Fuzzy expert analysis of the severity of mining machinery failure" in Applied Soft Computing, Elsevier BV (2020). https://doi.org/10.1016/j.asoc.2020.106459

A fuzzybased decision support model for effectiveness evaluation  a case study of examination of bulldozers
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 ...Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić. "A fuzzybased decision support model for effectiveness evaluation  a case study of examination of bulldozers" in International Journal of Industrial Engineering: Theory, Applications and Practice (2019)

The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis
EarthSurface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeLjiljana Vasić, Dragana Ž. Živojinovic, Vladana RajakovićOgnjanović, Huang Fen, Cao Jianhua. "The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis" in Environmental Earth Sciences, Springer Science and Business Media LLC (2021). https://doi.org/10.1007/s12665021093921

Fourth Summer Datathon on Linguistic Linked Open Data
Tijana Radović, Ranka Stanković (2023)The 4th Summer Datathon on Linguistic Linked Open Data (SDLLOD22) was held in Spain, in Cersedilla near Madrid, in May 2022, and organized by the COST Action NexusLinguarum. The school gathered interested researchers, academics, students who wanted to acquire and/or expand their knowledge in the field of linguistic linked data science. During the school, a spectrum of topics from the field of linked data was presented, from various ontologies, through document integration, annotation and natural language text processing tools ...Tijana Radović, Ranka Stanković. "Fourth Summer Datathon on Linguistic Linked Open Data" in Infotheca, Faculty of Philology, University of Belgrade (2023). https://doi.org/10.18485/infotheca.2023.23.1.6

Development of Integrated Fuzzy Model for Mine Management Optimization
Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)Technoeconomic, environmental and safety criteria generally affect the management of metallic and nonmetallic mining operations. The first basic question that needs to be addressed when planning ore mining is which methods are adequate and what is the optimal mining technology? Due to the complex geologic framework of ore deposits, geological exploration has rendered synonymous the inherent uncertainties, vagueness, and inaccuracies. As a result, subjective evaluation by engineers and expert experience have become increasingly important. Given that the natural language ...Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić. "Development of Integrated Fuzzy Model for Mine Management Optimization" in Comptes rendus de l’Académie Bulgare des Sciences, Bulgarian Academy of Sciences (2023). https://doi.org/10.7546/CRABS.2023.09.12

The Fuzzy–AHP Synthesis Model for Energy Security Assessment of the Serbian Natural Gas Sector
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 ...... class, i.e., depending on linguistic variables. Linguistic variables (LV) are those variables whose values are actually the word or words of natural language as the basis of human communication. Linguistic variables always consist of basic linguistic values. By adding linguistic modifiers (less, more, ...
... very, very much, etc.), as well as conjunctions (and, or, not), complex linguistic expressions can be obtained. Linguistic variables can be assigned one or more linguistic values that are related to numerical values through membership and class functions [48]. Symmetry 2020, 12, 908 5 of 42 For ...
... Figure 3. Linguistic variables (LV). The use of the trapezoidal 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 ...Aleksandar R. Madžarević, Dejan D. Ivezić, Miloš L. Tanasijević, Marija A. Živković. "The Fuzzy–AHP Synthesis Model for Energy Security Assessment of the Serbian Natural Gas Sector" in Symmetry, MDPI AG (2020). https://doi.org/10.3390/sym12060908

The Newton method for solving nonlinear equations based on aggregation operators
Nebojša M. Ralević, Dejan Ćebić (2019)Nebojša M. Ralević, Dejan Ćebić. "The Newton method for solving nonlinear equations based on aggregation operators" in XLVI International Symposium on Operational Research SYMOPIS, Kladovo, 1518.9.2019, Универзитет у Београду (2019)

Quantitative landslide risk assessment in the city of Tuzla
In the climatechanging conditions, geological environment interacts more dramatically with the urban fabric than before. The urbanization is expansive and more aggressive than before, but so are the weather extremes and longterm climate trends. In effect, many processes which can be triggered by either side, nature or engineering, are becoming more pervasive than before, and such is the case with landslides. Dealing and managing landslides requires few crucial steps, starting from collecting data on landslide location and typology – ...... of nominal classes, given in the original and aggregated map, into sets of binary variables, so that each class gives a new subvariable. For instance, engineering geological units were segregated into 9 subvariables (9 new rasters), that are binary (1 = observed engineering geological class, 0 ...
... lines. Subsequently, Euclidean distance from this line vector was calculated for each pixel in the area of interest. All these represent numeric variables, which were further normalized to 01 range. Figure 4. Digital Terrain Model of the study area. 3.3 Environmental factors Environmental ...
... risk. This raster dataset was nominal, just as in the case of engineering geological units, so the same procedure of its aggregation into dummy variables was followed. Distance to mining sites was calculated to depict disturbed zones, since mining in Tuzla region includes open pit coal and underground ...Miloš Marjanović, Biljana Abolmasov, Cvjetko Sandić, Miralem Mulać, Petar Begović. "Quantitative landslide risk assessment in the city of Tuzla" in SCGXiii International Symposium on Landslides. Cartagena, Colombia February 2226, 2021, International Society for Soil Mechanics and Geotechnical Engineering (2021)

Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules
The stability analysis of homogeneous rock slope following the Hoek–Brown failure criterion under the hypothesis of different flow rules is performed based on limit equilibrium and finite element methods. The applied failure criterion is the generalized Hoek–Brown that can be introduced as a shear/normal function in analysis applying different flow rules. The results are compared with those obtained by the application of equivalent shear strength parameters of the Mohr–Coulomb criterion, considering that this is still the most widely used ...Kružna klizna površ, HukBraunov kriterijum loma, Kriterijum popuštanja, Smičuća/normalna funkcija, Nivo napona, Verovatnoća i parametarska analizaSvetlana Melentijević, Zoran Berisavljević, Dušan Berisavljević, Claudio Olalla Marañón . "Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules" in Bulletin of Engineering Geology and the Environment , Springer (2024). https://doi.org/10.1007/s10064024036670

Development of integrated fuzzy model for mine management optimization
Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)... and geologists is most 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; ...
... 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 one aand, the criteria are analyzed and ...
... and options. The calculations were made in a specially developed FUZZYGWCS program [10], and the input elements were numerical values of linguistic variables. Table 1 shows the criteria matrix values and the calculated weight coefHicients. The scores and weights are represented by triangular fuzzy ...Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić. "Development of integrated fuzzy model for mine management optimization" in Comptes rendus de l'Académie Bulgare des Sciences (2023)