Претрага
926 items
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Steel Arch Support Deformations Forecast Model Based on Grey–Stochastic Simulation and Autoregressive Process
Relatively large deformations of the steel arch support in underground coal mines in the Republic of Serbia present one of the main problems for achieving the planned production of coal. Monitoring of the critical sections of the steel arch support in the underground roadways is necessary to gather quality data for the development of a forecasting model. With a new generation of 3D laser scanners that can be used in potentially explosive environments (ATEX), deformation monitoring is facilitated, while ...čelična podgrada, prognoza deformacija, vremenske serije, grey-stohastička simulacija, autoregresija, podzemni rudnik ugljaLuka Crnogorac, Suzana Lutovac, Rade Tokalić, Miloš Gligorić, Zoran Gligorić. "Steel Arch Support Deformations Forecast Model Based on Grey–Stochastic Simulation and Autoregressive Process" in Applied Sciences, MDPI AG (2023). https://doi.org/10.3390/app13074559
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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 ...... III. AVAILABILITY ASSESSMENT MODEL Figure 1 shows the conceptual model of the expert system for availability (A) evaluation based on fuzzy interference of reliability (R), maintainability (M) and supportability (S) input data. Input data are introduced to a model based on experts’ opinions. ...
... 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, Miloš ...
... but requires specific, quite complex IT system. Therefore, in this paper, an expert model, that integrates reliability, maintainability, and supportability in the measure of availability is proposed. This model is based on fuzzy sets theory and it is implemented to three types of bulldozers that ...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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Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study
Debris flows induced by intensive rainfall represent very hazardous phenomena in many parts of the World. Methods for prediction of runout distance of flow like mass movements are different and depending on the input data, rheology, and available or appropriate numerical solution. However, sometimes it is not easy to obtain pre event and post event high-resolution data in the rural or mountainous area. Thus, the topology of terrain is the most important input parameter for the every real case ...... 2007; Frank, 2017). As input, three quantities must be specified to perform a numerical calculation: (1) a digital elevation model (DEM), (2) source zone area and (3) model friction parameters. Pre- event DEM resolution characterizes the natural terrain surface geometry and it is therefore the most ...
... resolution affected a lot in results about deposition depth, but also on choosing right frictional parameter in rheological model. Method One of well used rheological model is Voellmy method (Voellmy, 1955) firstly used in snow avalanche models, which means that is basically one-phase. It is assumed ...
... precision in calculated eroded material, which is quite deep in this case. Input Data RAMMS uses DEM (Digital Elevation Model) as a basic data for defining simple geometry of model. Some researchers suggested 5x5m resolution as an optimal, explaining that even using smaller resolution gave quite similar ...Jelka Krušić, Biljana Abolmasov, Mileva Samardžić Petrović. "Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study" in 4th Regional Symposium on Landslides in the Adriatic Balkan Region, 23-25 October 2019, Sarajevo, Bosnia and Herzegovina, Geotechnical Society of Bosnia and Herzegovina (2019). https://doi.org/ 10.35123/ReSyLAB_2019
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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 ...... and high resolution Digital Terrain Model (DTM), also. Final models show accurate results comparing to the depths in deposition zone, but actual run-out distance of debris flow was longer than the measured run-out distance obtained by the SPH simulation model. Also, simulation results show heights ...
... velocity as well as pore water pressure if coupled model is included. Geoflow SPH proposed by Pastor 2009, already has been used on different cases in the world (Pastor et al. 2015, 2009, Cascini et al. 2014, Cuomo et al. 2014).Within the SPH model, it is possible to incorporate numerous rheological ...
... SPH model proposed by Pastor et al. (2009), defines propagations of mass as mixture of soil and water particles with calculation of velocity. In addition, calculation of pore water pressures propagation is possible to be obtained using Finite Difference Method coupled with two- phase model. Herein ...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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Model upravljanja investicionim projektima otvaranja površinskih kopova uglja
Cvjetko P. Stojanović (2015-04-27)Brze promene u okruženju pred rukovodioce postavljaju mnogobrojne zahteve,pre svega, one koji se tiču ostvarenja ciljeva u zadatom vremenu i raspoloživimsredstvima što zahteva fleksibilan pristup u organizovanju aktivnosti i efikasnost unjihovom sprovođenju.Upravljanje projektima, bilo koje vrste, suštinski, predstavlja veoma složenproces odlučivanja uslovljen velikim brojem ulaznih faktora. Ti faktori treba daomoguće fokusiranje na prioritete i ciljeve, praćenje realizacije, fleksibilnost uprevazilaženju teškoća, prilagođavanje promenama, te kontrolu nad ostvarenimrezultatima. Ovakav način upravljanja zahteva korišćenje proverenih tehnika i alata tetimski rad angažovanih na ...Cvjetko P. Stojanović. "Model upravljanja investicionim projektima otvaranja površinskih kopova uglja" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-04-27)
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Electronic Dictionaries - from File System to lemon Based Lexical Database
In this paper we discuss some well-known morphological descriptions used in various projects and applications (most notably MULTEXT-East and Unitex) and illustrate the encountered problems on Serbian. We have spotted four groups of problems: the lack of a value for an existing category, the lack of a category, the interdependence of values and categories lacking some description, and the lack of a support for some types of categories. At the same time, various descriptions often describe exactly the same ...... e-dictionaries to XML files compliant to LMF model, but further exploitation of these files was not implemented, neither for lexical database development nor for further processing (Stanković et al., 2013). Finally we considered the lemon model (Lexicon Model for Ontologies), which was derived from ...
... The main advantage of the lemon model for the research outlined in this paper was its support for linking with other (lexical) data and the possibility to access data by using the standardized SPARQL query language. The model pre- sented is based on the lemon model, but some modifica- tions and ...
... presented a new database model, developed upon the lemon model, as well as its application for mi- grating electronic morphological dictionaries from a single- user file system to a multi-user environment based on a re- lational database management system. The new lexical data model implemented as a lexical ...Ranka Stanković, Cvetana Krstev, Biljana Lazić, Mihailo Škorić. "Electronic Dictionaries - from File System to lemon Based Lexical Database" in Proceedings of the 11th International Conference on Language Resources and Evaluation - W23 6th Workshop on Linked Data in Linguistics : Towards Linguistic Data Science (LDL-2018), LREC 2018, Miyazaki, Japan, May 7-12, 2018, European Language Resources Association (ELRA) (2018)
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The Impact Assessment of NO2 Emission from District Heating Plant on Local Air Quality, the Case of Zemun, Belgrade
The Belgrade district heating system relies on fossil fuels in heat production, where natural gas has the largest share of around 95% and fuel oil with around 4.4%. The Zemun heating plant is completely fueled with fuel oil. Currently, it is the largest plant that is not fueled with natural gas. The objective of this paper is to assess the impact of NO2 from the Zemun heating plant on local air quality by analyzing and comparing the concentration of ...NO2, Zagađenje vazduha, Kvalitet vazduh na lokalnom nivou, Model disperzije, AERMOD, Daljinsko grejanje, BeogradBoban Pavlović, Uroš Pantelić, Marija Živković, Dejan Ivezić. "The Impact Assessment of NO2 Emission from District Heating Plant on Local Air Quality, the Case of Zemun, Belgrade" in Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, 10.10.-15.10.2021., University of Zagreb, Zagreb, Croatia; Instituto Superior Técnico, Lisbon, Portugal (2021)
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Geologic Information System of Serbia
Geologic information system of Serbia (GeolISS) represents repository for digital archiving, query, retrieving, analysis and geologic data visualization. The GeolISS is implemented through ESRI ArcGIS technology, and is designed to operate as a personal geodatabase (MS Jet 4.0 Engine) and SDE enterprise geodatabase in MS SQL Server. The objective of GeolISS implementation is integration of existing geologic archives, data from published maps at different scales, newly acquired field data, as well as Web publishing of geologic information. Physical implementation ...... BRANISLAV TRIVIĆ2, RANKA STANKOVIĆ3, OLIVERA KITANOVIĆ4 and NENAD BANJAC 5 Abstract Keywords: Geologic information system, Conceptual model, Logical model, Implementation, Geodatabase. Geologic information system of Serbia (GeolISS) represents repository for digital archiving, query, ...
... acquired field data, as well as Web publishing of geologic information. Physical implementation of GeolISS has been guided with conceptual and logical model in those specified the basic kinds of geologic entities of interest and how they are described. The attempt has been influenced by NADM-C1 imp ...Branislav Blagojević, Branislav Trivić, Ranka Stanković, Nenad Banjac, Olivera Kitanović. "Geologic Information System of Serbia" in Proceedings of the 17th Meeting of the Association of European Geological Societies, 14.-18. september 2011., Beograd : Srpsko geološko društvo (2011)
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Agent-based modeling as a support to an expert-based approach: Exploring individual heating systems transition
Expert-based energy scenarios are mainly developed following assumptions of experts and, in most cases, a limited number of stakeholders. Such an approach will provide satisfactory results in centrally managed energy sectors where further decisions could be envisaged relatively precisely (electricity production/distribution, district heating systems, etc.). The same approach will provide more uncertain outcomes of future energy structure in the household sector, where decisions related to consumption, selection of energy source, or application of specific technology are made by numerous ...Energetska tranzicija, Grejanje domaćinstava, Individualni sistemi grejanja, Energetsko planiranje, Integrisano energetsko planiranje, ABM, LEAP, SrbijaBoban Pavlović, Marija Živković, Dejan Ivezić. "Agent-based modeling as a support to an expert-based approach: Exploring individual heating systems transition" in South East European Conference on Sustainable Development of Energy, Water and Environment Systems 22 – 26 May 2022, Vlorë, Albania, Faculty of Mechanical Engineering and Naval Architecture, Zagreb (2022)
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AR, CR and ARCR modeling for simulations and analyses of karst groundwater quality parameters
Although an invisible component of the hydrologic cycle, groundwater generally takes precedence over other water resources in the area of drinking water supply. Among groundwater resources, karst aquifers tend to be rich in sufficiently-accessible amounts of high-quality water. During most of the year, this water requires only disinfection prior to delivery to the end user. However, in many cases extreme rainfall and/or sudden snow melt results in transient turbidity, increase in bacterial count and temporary contamination (e.g. increase in ...autocorrelation, cross-correlation, autoregressive model, cross-regressive model, autocross regressive model, nitrates, Banja Spring, Serbia.Vesna Ristić-Vakanjac, Marina Ćokorilo-Ilić, Petar Papić, Dušan Polomčić, Radisav Golubović. "AR, CR and ARCR modeling for simulations and analyses of karst groundwater quality parameters" in Geološki anali Balkanskoga poluostrva, National Library of Serbia (2018). https://doi.org/10.2298/GABP1879071R
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Optimizacija utovarno-transportnih sistema u funkciji planiranja površinskog kopa
Mirjana V. BANKOVIĆ (2018)tehnološki model, integralni model, planiranje, optimizacija,utovarno-transportni sistem, neto sadašnja vrednost projektaMirjana V. BANKOVIĆ. Optimizacija utovarno-transportnih sistema u funkciji planiranja površinskog kopa, Beograd:Rudarsko Geološki Fakultet, 2018
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Soil oscillation law parameter determination with the application of Lagrange’s theorem at “Kovilovača“ open pit
... načina tj. modela, koristeći pri tome vrednosti dobijene eksperimen- talnim merenjima. ♦ Određivanje parametara po modelu 1 Za dobijanje parametara (K) i (n) uglav- nom se koristi metoda najmanjih kvadrata, koja predstavlja uobičajeni model 3 . ♦ Određivanje parametara po modelu 2 U zakonu ...
... experimental measurements. ♦ Determination of parameters by model 1 The smallest square method is mainly used to obtain the parameters K and n which represents a common model [3]. ♦ Determination of parameters according to model 2 In the rock mass oscillation velocity law given by equation ...
... A. Sadovski. Za određivanje parametara u jednačini Sadovskog, pored uobičajenog modela - metode najmanjih kvadrata, prikazan je još jedan model uz primenu Lagranžove teoreme. Pri tom je konstatovano da se oba modela mogu koristiti za izračunavanje brzine oscilovanja stenske mase. Ključne reči: ...Suzana Lutovac, Nebojša Vidanović, Čedomir Beljić, Zoran Gligorić. "Soil oscillation law parameter determination with the application of Lagrange’s theorem at “Kovilovača“ open pit" in Mining and Metallurgy Engineering Bor, Bor : Mining and Metallurgy Institute Bor (2015). https://doi.org/10.5937/MMEB1503053L
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Izbor optimalnog sistema bager damper primenom modela simulacije na površinskom kopu rudnika bakra Majdanpek
Kosta Prstić (1980)Kosta Prstić. Izbor optimalnog sistema bager damper primenom modela simulacije na površinskom kopu rudnika bakra Majdanpek, Beograd:Rudarsko-geološki fakultet, 1980
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Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines
This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems EngineeringUgljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković. "Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines" in Machines, MDPI AG (2022). https://doi.org/10.3390/machines10110995
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Numerical Models of Debris Flows with Entrainment Analysis-Case Studies from the Republic of Serbia
The results of material entrainment analysis in RAMMS debris flow software, as well as numerical models of final flow heights for two case studies from the Republic of Serbia are presented. Both of debris flow cases started with initial sliding of huge volume block, prolonging to behave as flowing process. Results of the analysis showed that entrainment material affects final results of transportation model, runout distance, deposition area and volume of debris flow. In both cases entrainment volume is very ...Jelka Krušić , Biljana Abolmasov, Miloš Marjanović. "Numerical Models of Debris Flows with Entrainment Analysis-Case Studies from the Republic of Serbia" in Understanding and Reducing Landslide Disaster Risk. WLF 2020. ICL Contribution to Landslide Disaster Risk Reduction, Springer, Cham (2021). https://doi.org/10.1007/978-3-030-60706-7_25
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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
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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)
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Validation of vulnerability assessment by means of the Time Dependent, Model: case study from the Slovenian karst catchment
Groundwater vulnerability assessment methods are continuously being developed and existing methods are very often modified to provide better simulation of natural protection conditions and more objective results. Most frequently used methods are based on calculation of predefined parameters influencing water infiltration and underground flow, which can often lead to bias conclusions related to vulnerability evaluations. Some other methods, like the Time Dependent Model (TDM) are based on an approach, where parametrization is obtained at the final stage of the ...Ocena ranjivosti podzemnih voda, karstne podzemne vode, TDM metoda, delineacija sanitarnih zona, Slovenački karstVladimir Živanović, Nataša Ravbar, Igor Jemcov. "Validation of vulnerability assessment by means of the Time Dependent, Model: case study from the Slovenian karst catchment" in Proceedings of IAH2019, the 46th Annual Congress of the International Associaton of Hydrogeologists, Málaga (Spain), September 22-27, 2019, International Association of Hydrogeologists (IAH) (2019)
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Numerical modelling of the roughly simultaneous emplacement of two distinct ophiolite belts
Nikola Stanković, Vesna Cvetkov, Vladica Cvetković. "Numerical modelling of the roughly simultaneous emplacement of two distinct ophiolite belts" in 5th Congress Geologists of the Republic of North Macedonia, Ohrid, 28-29. 10. 2024, Македонско геолошко друштво (2024)
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A contribution to the knowledge of facial diversity of Badenian sediments in the Belgrade area
Filip Anđelković, Dejan Radivojević (2018)... kog i panonskog kata, sedimenti kvartara i recentno zemljište. Istraživani prostor se nalazi u oblasti severne Šumadije. Geološki ovaj teren pripada južnom obodu Panonskog basena (Marović et al., 2007). Proučavanja badenskih sedimenata su detaljno vršena tokom XX veka, u okviru Osnov ...
... ojavljuju na nekoliko izdanaka u blizini Višnjice i Slanaca. U toj oblasti su razvijeni i ceritski krečnjaci (na brdu Lipak). Na ovom delu terena mogu se uočiti „prelazni oblici“ između subfacija, a negde je uključena i peskovita komponenta. Rakovički klastiti obuhvataju dobro vezane ko ...Filip Anđelković, Dejan Radivojević. "A contribution to the knowledge of facial diversity of Badenian sediments in the Belgrade area" in 17th Serbian Geological Congress, Vrnjačka Banja, 17-20 maj 2018, Srpsko geološko društvo (2018)