Претрага
33 items
-
Multi-Criteria Fuzzy-Stochastic 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, decision-making 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, open-cast mine, geometric Brownian motionDušan Polomčić, Zoran Gligorić, Dragoljub Bajić, Miloš Gligorić, Milanka Negovanović. "Multi-Criteria Fuzzy-Stochastic Diffusion Model of Groundwater Control System Selection" in Symmetry, MDPI AG (2019). https://doi.org/10.3390/sym11050705
-
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 ...... for the assessment of availability based on expert judgment. The model will be shown in the case study (on the example) of bulldozers working in the open-pit lignite mine. Keywords: availability; fuzzy theory; AHP multi-criteria analysis; expert judgment; bulldozer 1. Introduction Various explanations ...
... for the assessment of availability based on expert judgment. The model will be shown in the case study (on the example) of bulldozers working in the open-pit lignite mine. Keywords: availability; fuzzy theory; AHP multi-criteria analysis; expert judgment; bulldozer 1. Introduction Various explanations ...
... indicators are of hybrid nature. Some can be expressed numerically, in the form of a time-dependent function, and some only on the basis of expert judgment. Among these indicators, uncertainty, subjectivity, versatility, inconsistency, and mutual overlap prevail. In scientific literature, fuzzy logic ...Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović. "Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine" in Energies, MDPI AG (2019). https://doi.org/10.3390/en12214044
-
Development of an integrated model for open-pit-mine discontinuous haulage system optimization
Miodrag Čelebić, Dragoljub Bajić, Sanja Bajić, Mirjana Banković, Duško Torbica, Aleksej Milošević , Dejan Stevanović (2024)Miodrag Čelebić, Dragoljub Bajić, Sanja Bajić, Mirjana Banković, Duško Torbica, Aleksej Milošević , Dejan Stevanović . "Development of an integrated model for open-pit-mine discontinuous haulage system optimization" in Sustainability, MDPI (2024). https://doi.org/10.3390/su16083156
-
Estimating hydraulic parameters for the complex hydrodynamic models
Hydrodynamic models have usually been calibrated manually, by trial-and-error, with different values of hydraulic parameters and hydraulic characteristics of boundary conditions. This method of calibration and estimation of hydraulic parameters requires an extensive knowledge and experience of experts, but whether the resulting solution includes an optimal set of parameters still remains an open question. An optimization method founded upon the Gauss-Marquardt-Levenberg algorithm, along with PEST software based on that algorithm, introduces automation of model calibration with regularization, which substantially ...Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin. "Estimating hydraulic parameters for the complex hydrodynamic models" in Mining and Metallurgy Engineering Bor, Centre for Evaluation in Education and Science (CEON/CEES) (2018). https://doi.org/10.5937/mmeb1704029P
-
Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“
Najčešće se kalibracija hidrodinamičkih modela vršila manuelno - „probanjem“ sa različitim vrednostima hidrauličkih parametara i hidrauličkih karakteristika graničnih uslova. Ovakav način rada zahteva veliko znanje i iskustvo eksperta, pri čemu ostaje otvoreno pitanje da li dobijeno rešenje ima optimalan skup parametara. Primenom optimizacione metode, koja se zasniva na Gauss-Marquardt-Levenberg-ovom algoritmu, i PEST softvera, ...Dragoljub Bajić, Dušan Polomčić, Jelena Ratković, Predrag Pajić. "Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“" in 9. Međunarodni simpozijum o upravljanju podzemnim resursima, Zaječar 2019., Megatrend Univerzitet, Fakultet za menadžment, Zaječar (2019)
-
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
-
Depth estimation of archeological objects using Euler 3D deconvolution of magnetic data
Vesna Cvetkov, Ilija Vasiljević, Mirko Petković. "Depth estimation of archeological objects using Euler 3D deconvolution of magnetic data" in 5. Hrvatski geološki kongres. Abstract Book 5th Croatian Geological Congress, Hrvatski geološki institut (2015)
-
Formative evaluation of e-learning projects with the logical framework approach
... Evaluation of E-learning projects is a topic of great interest and growing importance. The evaluation of a project is the construction of the overall judgment, based on a quali-quantitative determination of the benefits and costs associated, with scientific criterion, of a project (evaluand). The purposes ...
... evaluation is aimed to improve the strategy, or the processes during the development. The summative evaluation aims to take lessons, insights, judgment and awareness about taken decisions and projects. Evaluations can apply to various evaluands, such as products, projects, programs, organizations ...Roberto Linzalone, Giovani Schiuma, Ivan Obradović, Ranka Stanković. "Formative evaluation of e-learning projects with the logical framework approach" in The Sixth International Conference on e-Learning (eLearning-2015), September 2015, Belgrade, Serbia, Belgrade Metropolitan Univesity (2015)
-
INVENTS: A Hybrid Mine Ventilation Planning and Design System
Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper we ...... represents a formalization of the expert knowledge in the mine ventilation field. In this paper we present the design methodology of the hybrid system INVENTS, as well as system structure and user interface. Keywords: hybrid systems, mine ventilation, expert systems 1. Introduction The methodology ...
... obtained after the desired analysis by SimVent can be exported to VENTEX – a diagnostic expert system that performs the analysis of obtained results according to a number of criteria. The result of such an expert analysis is an estimate of the validity and effectiveness of the ventilation system followed ...
... ventilation simulation in complex mine ventilation networks - SimVent and a diagnostic expert system for the analysis of ventilation systems - VENTEX. Software packages ResNet and SimVent as well as the expert system Ventex are developed for IBM PC and compatible computer systems. ResNet is a program ...Lilić Nikola, Stanković Ranka, Obradović Ivan. "INVENTS: A Hybrid Mine Ventilation Planning and Design System" in Proceedings of International Scientific Conference of FME Session 4: Automation Control and Applied Informatics , Hong Kong : iConcept Press (2013)
-
VENTEX: An Expert System for Mine Ventilation Systems Analysis
Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...... Измењено: 2023-10-14 04:20:47 VENTEX: An Expert System for Mine Ventilation Systems Analysis Ranka Stanković, Nikola Lilić, Ivan Obradović Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] VENTEX: An Expert System for Mine Ventilation Systems Analysis | ...
... the numerical SimVent system. The result is VENTEX, a coupled expert system incorporating both procedural and declarative knowledge, that offers the possibility for a more profound exploitation of the available software at an expert level. The paper presents the strategy of mine ventilation ...
... Knowledge in expert systems basically consists of facts and heuristics which can be represented by means of rules, frames, semantic networks and other formalisms. Since knowledge is the key factor in problem solution and decision making, the quality and usability of an expert system is basically ...Ranka Stanković, Nikola Lilić, Ivan Obradović. "VENTEX: An Expert System for Mine Ventilation Systems Analysis" in YU Info '96 Brezovica, Društvo za informacione sisteme i računarske mreže (1996)
-
Fuzzy Model for Risk Assessment of Machinery Failures
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 ...... to use expert judgment that includes an opinion on the quality of the backup element activation system. If the six relation is used, the outcome will be the same in both cases, which does not work here. Thus, in order to obtain an adequate risk assessment, the incorporation of expert judgment into ...
... through linear interpolation. Symmetry 2020, 12, 525 8 of 26 3.2.2. Fuzzification of the Data Obtained Based On Expert Judgment Fuzzification of the data based on expert judgment was accomplished using the membership degree of the fuzzy sets. The membership degree differs from the membership function ...
... often represents a mathematically defined quantity, but not always, and the severity of a consequence is of a qualitative nature and is based on expert judgment. The essential comparative advantage of the fuzzy model is that the qualitative meaning of variables is not lost, whether in the performance analysis ...Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković. "Fuzzy Model for Risk Assessment of Machinery Failures" in Symmetry, MDPI AG (2020). https://doi.org/10.3390/sym12040525
-
Prioritization of strategic measures for strengthening the security of supply of the Serbian natural gas sector
To strengthen the security of supply of the Serbian gas sector, it is necessary to analyze the impact of planned strategic measures. The analysis involves the identification of the most influential threats to the security of natural gas supply and prioritization of the strategic measures for overcoming the consequences of threats. The proposed methodology is based on Fuzzy Analytic Hierarchy Process. The obtained weights for the identified threats and strategic measures are formed according to experts' judgments. The results ...Sigurnost snabdevanja, Donošenje odluka, Snabdevanje prirodnim gasom, Fazi AHP, Energetski indikatoriBoban Pavlović, Dejan Ivezić, Marija Živković. "Prioritization of strategic measures for strengthening the security of supply of the Serbian natural gas sector" in Energy Policy, Elsevier BV (2020). https://doi.org/10.1016/j.enpol.2020.111936
-
Ventex: an expert system for mine ventilation systems analysis
roblems relating to mine ventilation systems analysis are usually of a very complex nature. They involve the estimation of numerous interdependent parameters pertaining to the network status, ventilation status, ventilation system stability, air current losses, climate conditions, gas state, fire risk and dangerous dust pollution risk. The solution to these problems relies, to a great extent, on numerical methods. With the development of computer technology these methods were incorporated as numerical routes in software packages, such as the mine ...Nikola Lilić, Ranka Stanković, Ivan Obradović. "Ventex: an expert system for mine ventilation systems analysis" in Mining Technology, United Kingdom (1997)
-
Razvoj integralnog modela za optimizaciju diskontinualnog sistema proizvodnje na površinskim kopovima nemetala
Miodrag Čelebić (2024)Izbor optimalne mehanizacije u diskontinualnom sistemu transporta je jedna od najvažnijih odluka koju treba donijeti prilikom projektovanja površinskih kopova. Pri izboru optimalne mehanizacije, uticaj ima veliki broj faktora, kako prirodnih – geoloških i ekoloških, tako i tehničkih, ekonomskih i socijanih. Neki od njih se mogu izraziti numerički, u određenim mijernim jedinicama, a neki opisno, lingvističkim varijablama, shodno uslovima koji vladaju na rudnim ležištima, a koje karakterišu visok stepen neizvjesnosti i neodređenosti kako prilikom istraživanja, tako i tokom procesa eksploatacije ...izbor mehanizacije, tehnologija eksploatacije, diskontinualani sistem, ekspertsko odlučivanje, lingvističke varijable, MCDM, FAHPMiodrag Čelebić. Razvoj integralnog modela za optimizaciju diskontinualnog sistema proizvodnje na površinskim kopovima nemetala, Beograd : [M. Čelebić], 2024
-
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 non-metallic 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
-
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 ...... Измењено: 2023-10-14 04:10:15 A Fuzzy Expert Model for Availability Evaluation Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] A Fuzzy Expert Model for Availability Evaluation | Dejan Ivezić ...
... as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 978-1-7281-0702-8/19/$31.00 ©2019 IEEE A Fuzzy Expert Model for Availability Evaluation Dejan Ivezic Faculty of Mining and Geology University of Belgrade Belgrade, Serbia dejan.ivezic@rgf.bg ...
... state. For time state tracking, specific IT structure is necessary. Such structure is often very expensive and unavailable. An alternative is the expert system, which can absorb partial indicators of the availability, including their uncertainty, diversity, relativity. In this article, an expert’s ...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)
-
A multi-criteria approach for assessing the potential of renewable energy sources for electricity generation: Case Serbia
When assessing the potential of renewable energy alternatives for electricity generation, it is necessary to implement a multi-perspective approach that includes economic, technical, environmental, and socio-political criteria. For the evaluation of criteria and alternatives, the Fuzzy Analytical Hierarchy Process (FAHP) method is applied. The obtained weights are formed according to the values of energy indicators and expert judgments. The use of a fuzzy numerical value scale for the assessment of expert judgments and energy indicators provides a more sensitive ...... for assessment of RES potentials for electricity generation, a comparison matrix is formed based on experts’ judgment of proposed criteria (C1–C4). A linguistic variable of each expert’s judgment is converted into TFNs. Table 7 introduces the aggregated comparison matrix based on experts’ judgments for ...
... data from expert assessments and studies of international expert organizations were used. The novelty of this paper consists of the following: • Expert assessment of the proposed economic, environmen- tal, socio-political, and technical criteria, as well as the as- sessment of available RES technologies ...
... (FAHP) method is applied. The obtained weights are formed according to the values of energy indicators and expert judgments. The use of a fuzzy numerical value scale for the assessment of expert judgments and energy indicators provides a more sensitive scoring system for differences between values than ...Boban Pavlović, Dejan Ivezić, Marija Živković. "A multi-criteria approach for assessing the potential of renewable energy sources for electricity generation: Case Serbia" in Energy Reports, Elsevier BV (2021). https://doi.org/10.1016/j.egyr.2021.02.072
-
A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System
This paper presents a model for determining fuzzy evaluations of partial indicators of the availability of continuous systems at coal open pits using a neuro-fuzzy inference system. The system itself is a combination of fuzzy logic and artificial neural networks. The system availability is divided into partial indicators. By combining the fuzzy logic and artificial neural networks, a model is obtained that has the ability to learn and uses expert judgment for that learning. This paper deals with the ...системи, континуални системи експлоатације (роторни багер-транспортер-дробилично постројење), рударство, расположивост, меко рачунарство, фази логика, ANN, ANFISMiljan Gomilanović, Miloš Tanasijević, Saša Stepanović, Filip Miletić. "A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System" in Energies, MDPI AG (2023). https://doi.org/10.3390/en16072958
-
Development of the hybrid MCDM model for evaluating and selecting bucket wheel excavators for the modernization process
This paper presents a methodology for evaluating and ranking different bucket wheel excavators (BWE) for determining which machine should enter in the process of revitalization and modernization. Various multicriteria methods are used. Combining them achieves the best effect when choosing BVE for the modernization process. AHP, TOPSIS, VIKOR, and PROMETHEE methods are used. The hybrid models are developed from the multi-criteria decision making (MCDM) methods and they are used to evaluate the basic indicators that characterize the operation of ...Snezana Savkovic, Predrag Jovancic, Stevan Djenadic, Milos Tanasijevic, Filip Miletic. "Development of the hybrid MCDM model for evaluating and selecting bucket wheel excavators for the modernization process" in Expert Systems with Applications, Elsevier BV (2022). https://doi.org/10.1016/j.eswa.2022.117199
-
A fuzzy-based 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 fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers" in International Journal of Industrial Engineering: Theory, Applications and Practice (2019)