Претрага
2950 items
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Application of machine learning for diagnosing the operation of a deep well pump in oil production
Maja Trikić (2024)This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost... have variable frequencies and limited durations. Its primary purpose is to decompose a signal or image into different levels of resolution or scales. There are various types of wavelet functions, differing in shape and smoothness, and the choice depends on what aspect of the signal or image is being ...
... condition of the pumping system and assessing the characteristics of the fluid in the wellbore. The primary goal of computer-controlled oil extraction using deep well pumping is precisely to obtain an accurate downhole dynamogram. 16 4. MACHINE LEARNING Machine learning, a subset of artificial ...
... from the minority class rather than just making copies of existing examples. 6.3.3. Metrics for imbalanced datasets Many studies use accuracy, which measures the ratio between the number of correctly classified samples and the total number of samples. However, with imbalanced datasets, accuracy ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
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Arsenic in Tap Water of Serbia´s South Pannonian Basin and Arsenic Risk Assessment
Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)... shown a significantly higher odds ratio and higher standardized incidence rates for the occurrence of type 2 diabetes in the population exposed to arsenic, compared to the unexposed population in Serbia [38]. The highest safe standard for cancer risk is 1 per 10,000 and the lowest standard 1 per 1,000 ...
... indicates the existence of toxic risk. Futhermore, in the study area the minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 persons, and this should indicate the importance of developing a regional ...
... this study, and consequently with higher estimated toxic and carcinogenic risk should be con- nected to the new treatment for water supply. The minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 ...Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić. "Arsenic in Tap Water of Serbia´s South Pannonian Basin and Arsenic Risk Assessment" in Polish Journal of Environmental Studies (2012)
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Wordnet Development Using a Multifunctional Tool
Ivan Obradović, Ranka Stanković (2007)In this paper we present a multifunctional tool for manipulating heterogeneous language resources. The tool handles electronic dictionaries, wordnets and aligned texts, and provides for their synchronous use in various tasks. We focus here on the description of the possibilities this tool offers in the development of wordnets. Besides the wordnet module which enables parallel handling of two wordnets, other modules, such as the module for morphological dictionaries and the module for aligned texts, as well as available finite ...... dictionaries which consist of morphological dictionaries of lemmas for simple and compound words, but also of bilingual and multilingual dictionaries - manipulation of parallel aligned texts, allowing for various forms of their presentation and usage - conversions from different formats such ...
... developed in C# and operates on the .NET platform. An important feature of WS4LR is its flexibility expressed both by the possibility of setting environment parameters and by the possibility of invoking command- line routines and using external Perl, Awk, and XSLT scripts. WS4LR functions and their usage ...
... bilingual word list and a multilingual dictionary of proper names. However, the main task of this module is to enable the manipulation of the system of morphological dictionaries of canonical forms, or lemmas, for both simple and compound words. Morphological dictionaries are of great importance ...Ivan Obradović, Ranka Stanković. "Wordnet Development Using a Multifunctional Tool" in Proceedings of the International Workshop Computer Aided Language Processing (CALP) '2007, Borovets, Bulgaria, September 2007, - (2007)
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Concepts for Improving Machine Learning Based Landslide Assessment
Miloš Marjanović, Mileva Samardžić Petrović, Biljana Abolmasov, Uroš Đurić. "Concepts for Improving Machine Learning Based Landslide Assessment" in Natural Hazards GIS-based Spatial Modeling Using Data Mining Techniques, Advances in Natural and Technological Hazards Research, volume 48, Springer Nature Switzerland AG 2019 (2019). https://doi.org/10.1007/978-3-319-73383-8_2
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State and perspective of individual household heating in Serbia: A survey-based study
This paper presents the results of the household survey on individual household heating systems in Serbia. The survey was conducted in the period October to December 2020 with the participation of 1100 households with individual household heating systems. The information collected in the questionnaire can be separated into three main parts: basic household data, current heating system characteristics, and households’ perceptions and attitudes. The survey results provide unique and comprehensive information concerning individual household heating systems and the main ...Boban Pavlović, Dejan Ivezić, Marija Živković. "State and perspective of individual household heating in Serbia: A survey-based study" in Energy and Buildings, Elsevier BV (2021). https://doi.org/10.1016/j.enbuild.2021.111128
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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
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The external aggregation Newton's method for solving nonlinear equations and applications
Marija Paunović, Dejan Ćebić, Nebojša Ralević. "The external aggregation Newton's method for solving nonlinear equations and applications" in The University Thought - Publication in Natural Sciences, Centre for Evaluation in Education and Science (CEON/CEES) (2020). https://doi.org/10.5937/univtho10-24982
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Integrated Stratigraphy of the Middle–Upper Jurassic of the Krížna Nappe, Tatra Mountains
carbon and oxygen isotopes, radiolarians, calcareous dinoflagellates, radiolarites, Krížna Nappe, West ern Carpathians, Tethys... upper part of the underlying red nodular limestones, above the location of index ammonites, displays several cha- racteristic features of condensed deposits, such as a concen- tration of microborings in bioclasts as well as the presence of ferruginous macrooncoids, pelagic stromatolites and glau- ...
... in the Western Tatra Mountains is poorly de- fined, which results from the scarcity of index fossils, in- completeness of the sections, as well as the common occur- rence of condensations and hiatuses (Jach and Starzec, 2003; Gradzinski ef al., 2004). The Bosifra-crinoidal lime- stones studied ...
... nodular limestonc of the Le- jJowa Valley (samples Lb91, 100, Lc17—39) and Filipka Va- lley sections (sample Fk37), yield a cyst association, with Stomiosphaera moluccana Wanner accompanied by Car- pistomiosphaera borzai (Nagy) (Figs 4, 7, 13C). The latter cyst is the index marker of the Borzai Zone ...Renata Jach, Nevenka Đerić, Špela Goričan, Daniela Reháková. "Integrated Stratigraphy of the Middle–Upper Jurassic of the Krížna Nappe, Tatra Mountains" in Annales Societatis Geologorum Poloniae (2014)
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Arsenic in tape waters of the south Pannonian basin (Serbia) and arsenic risk assessment
Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)... shown a significantly higher odds ratio and higher standardized incidence rates for the occurrence of type 2 diabetes in the population exposed to arsenic, compared to the unexposed population in Serbia [38]. The highest safe standard for cancer risk is 1 per 10,000 and the lowest standard 1 per 1,000 ...
... indicates the existence of toxic risk. Futhermore, in the study area the minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 persons, and this should indicate the importance of developing a regional ...
... this study, and consequently with higher estimated toxic and carcinogenic risk should be con- nected to the new treatment for water supply. The minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 ...Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić. "Arsenic in tape waters of the south Pannonian basin (Serbia) and arsenic risk assessment" in Polish Journal of Enivronmental Studies 21 no. 6, Olsztyn, Poland : Polish Journal of Enivronmental Studies (2012): 1783-1790
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Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model
The Majdanpek open pit mine south district is currently active mining prospect of copper ore exploitation in eastern Serbia. Its depth is approaching the termination depth and occurrences of large-scale instabilities and global instability of the final pit slope is possible. These can generate catastrophic mass movement inside an area that encloses a regional road route and the Pek River bed which is channelled along the outer contour of the pit. The displacements that were noted in early 2023, in the ...Miloš Marjanović, Stefan Milanović, Nikola Simić, Lazar Kričak. "Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model" in Regional Symposium on Landslides in the Adriatic-Balkan Region, Belgrade, 15-18th May 2024, University of Belgrade, Faculty of Mining and Geology (2024). https://doi.org/10.18485/resylab.2024.6.ch46
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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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Отпад из процеса сагоревања угља као сировина за добијање елемената ретких земаља
Бојан Земљак (2024)Због великог броја индустрија у којима се користе ови ресурси, глобална економија се у великој мери ослања на елементе ретких земаља. Елементи ретких земаља су есенцијална сировина — материјал за развој савремених технологија, али у односу на њихову огромну потражњу, њихово вађење је ограничено и повезано је са значајним утицајима на животну средину. Због њихове ограничене доступности, проблема који се јављају при процесима експлоатације, све више и више земаља почиње да тражи повољније могућности вађења елемената [REE] из секундарних ...... calcium on dissolution and precipitation reactions of amorphous silica at high alkalinity. Cement and Concrete Research, 87, p.1-13. [195] Kumar, S., Chauhan, P.K., Sharma, R.P. and Uma, R., 2021. Compression of the laser pulse in magnetized plasma having relativistic regime. Opfik, 242, p.167130 ...
... R.K., Parhi, P.K. and Mishra, S., 2019. Bioleaching approach for extraction of metal values from secondary solid wastes: a critical review. Hydrometallurgy, 189, p.105122. [212] Vakilchap, F., Mousavi, S.M., Baniasadi, M. and Farnaud, S., 2020. Development and evolution of biocyanidation in metal ...
... A., 2021. Rare earth metals from secondary sources: Review of potential supply from waste and byproducts. Resources, Conservation and Recycling, 167, p.105213. [138] Filho, W.L., Kotter, R., Čzuyar, P.G., Abubakar, I.R., Eustachio, J.H.P.P. and Matandirotya, N.R., 2023. Understanding: Rare Earth ...Бојан Земљак. Отпад из процеса сагоревања угља као сировина за добијање елемената ретких земаља, 2024
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Development of integrated fuzzy model for mine management optimization
Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)... / faut covered, observed and marls; breccias. / photogeologically M Bauxtedeposis and occurrences. / Underground mining, in progress. / PA la 20 96 andabandoned - Open-pit mining, in progress O7 - 0OČ andabandoned Fig. 1. Geological map of the study area (modified [9]) Methodology. As mentioned ...
... aspects, ensuring of a safe and healthy work environment, and the possibility of sustainable ore extraction. An inadequate technology and its parameters can considerably reduce the benefits of mining.,, as well as bear upon economic viability and safety, which is one of the important criteria ...
... echnology. The great advantage of fuzzy logic and heuristic methods need to be empha- sized in connection with geological exploration of ore deposits. It is primarily related to the complexity of geologic structures and the physical and mechanical properties of rocks. In such circumstances, engineer ...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)
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Пројекат ПРИЗМА: Карактеризација и технолошки поступци за рециклажу и поновну употребу флотацијске јаловине рудника „Рудник“
Владимир Симић, Стефан Петровић, Филип Арнаут, Весна Цветков, Милена Костовић, Драган Радуловић, Јовица Стојановић, Владимир Јовановић, Дејан Тодоровић, Нина Николић, Јелена Сенћански, Грозданка Богдановић, Драгана Мариловић (2024)Владимир Симић, Стефан Петровић, Филип Арнаут, Весна Цветков, Милена Костовић, Драган Радуловић, Јовица Стојановић, Владимир Јовановић, Дејан Тодоровић, Нина Николић, Јелена Сенћански, Грозданка Богдановић, Драгана Мариловић. "Пројекат ПРИЗМА: Карактеризација и технолошки поступци за рециклажу и поновну употребу флотацијске јаловине рудника „Рудник“" in Записници Српског геолошког друштва, Београд : Српско геолошко друштво (2024)
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On the distribution modulo 1 of the sum of powers of a Salem number
Dragan Stankov (2016)It is well known that the sequence of powers of a Salem number θ, modulo 1, is dense in the unit interval, but is not uniformly distributed. Generalizing a result of Dupain, we determine, explicitly, the repartition function of the sequence , where P is a polynomial with integer coefficients and θ is quartic. Also, we consider some examples to illustrate the method of determination.Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomialsDragan Stankov. "On the distribution modulo 1 of the sum of powers of a Salem number" in Comptes rendus Mathematique (2016). https://doi.org/10.1016/j.crma.2016.03.012
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Critical disorder and critical magnetic field of the nonequilibrium athermal random-field Ising model in thin systems
Svetislav Mijatović, Dragutin Jovković, Sanja Janićević, Đorđe Spasojević. "Critical disorder and critical magnetic field of the nonequilibrium athermal random-field Ising model in thin systems" in Physical Review E, American Physical Society (APS) (2019). https://doi.org/10.1103/PhysRevE.100.032113
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Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils
Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov (2021)MICP process, kinetic study, calcite, vaterite, MALDI-TOF identification, Bacillus licheniformis, Sporosarcina pasteurii... Urea-CaCl2 agar and broth [20], and (iii) YE-CaCl2 agar and broth (modified of Urea-CaCl2 media; Urea was replaced with 4.0 g/L yeast extract). Overnight bacterial suspension aliquots (0.3 mL) were transferred into previously mentioned liquid media, adequate dilutions were made, and enumeration of bacteria ...
... S. pasteurii DSM 33 and B. simplex was slower, reducing the total concentration of calcium ions after a 3- and 5-day incubation period, respectively. In the case of B. muralis and B. simplex, instantaneous mineralization of calcium ions was not observed, and the concentration of free ions was lightly ...
... “goodness of fit” tests for Urea concentration, pH value and cell concentration prediction models, Table S3: The “goodness of fit” tests for amount of precipitate, pH value and reduction of Ca2+ ions prediction models. Author Contributions: Conceptualization, O.Š. and S.M.; methodology, A.T., A.R. and D.C ...Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov. "Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils" in Microorganisms, MDPI AG (2021). https://doi.org/10.3390/microorganisms9081691
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Terminological and lexical resources used to provide open multilingual educational resources
Open educational resources (OER) within BAEKTEL (Blending Academic and Entrepreneurial Knowledge in Technology enhanced learning) network will be available in different languages, mostly in the languages of Western Balkans, Russian and English. University of Belgrade (UB) hosts a central repository based on: BAEKTEL Metadata Portal (BMP), terminological web application for management, browse and search of terminological resources, web services for linguistic support (query expansion, information retrieval, OER indexing, etc.), annotation of selected resources and OER repository on local edX ...... involves e-learning and computer-assisted learning and instruction and the other consists of NLP tools for analysis and use of language by machines [1]. The usage and application of the research done in the field of the NLP has been present in the domain of education from the 1960s. One of the first advances ...
... ALEKSANDRA TOMAŠEVIĆ University of Belgrade, Faculty of Mining and Geology, aleksandra.tomasevic@rgf.bg.ac.rs BOJAN ZLATIĆ University of Belgrade, Faculty of Mining and Geology, bojan.zlatic@rgf.bg.ac.rs Abstract: Open educational resources (OER) within BAEKTEL (Blending Academic and Entrepreneurial Knowledge ...
... morphology of Serbian language and the complexity of terms (they are the most often composed of two or more words called multi word units) it is not a simple process. Members of Language Resources and Technologies Society developed semiautomatic approach for term recognition, extraction and lemmatization ...Biljana Lazić, Danica Seničić, Aleksandra Tomašević, Bojan Zlatić. "Terminological and lexical resources used to provide open multilingual educational resources" in The Seventh International Conference on eLearning (eLearning-2016), 29-30 September 2016, Belgrade, Serbia, Belgrade : Belgrade Metropolitan University (2016)
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Application of stochastic models for mine planning and coal quality control
... effect of mining from different benches of the surface mine, i. e., whether or not the required quantity and quality of coal can be met during the planning period. Mine planning is divided into four categories: long-term, medium-term, short-term, and operational planning [10]. The primary objective ...
... exactly – without approximation. Simulation methodology of coal quality control The primary objective of the simulation is to determine a sequence of mining tasks to deliver the required coal quality and quantity to the power plants in the short-to-medium term. Simulation algorithms currently used in ...
... number of layers in piles and the contribution that each seam from each block adds to the total mass of the pile. When the number of layers and mass (size) of the pile is reached the algorithm stops, takes the weighted average of the qualities from the blocks included in this specific pile, and starts ...Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković. "Application of stochastic models for mine planning and coal quality control" in Thermal Science, Belgrade : Vinča Institute of Nuclear Sciences (2014). https://doi.org/10.2298/TSCI130201031S
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Bridging Computational Lexicography and Corpus Linguistics: A Query Extension for OntoLex-FrAC
OntoLex, dominantni standard zajednice za mašinski čitljive leksičke resurse u kontekstu RDF-a, Linked Data i tehnologija Semantičkog veba, trenutno se proširuje sa posebnim modulom za Frekvencije, Primere i Informacije zasnovane na Korpusu (OntoLex-FrAC). Predlažemo novi komponent za OntoLex-FrAC, koji se bavi inkorporacijom korpusnih upita za (a) povezivanje rečnika sa korpusnim mašinama, (b) omogućavanje RDF baziranih web servisa da dinamički razmenjuju korpusne upite i podatke odgovora, i (c) korišćenje konvencionalnih upitačkih jezika za formalizaciju unutrašnje strukture kolokacija, skica reči i ...standardizacija, digitalna leksikografija, OntoLex, upiti korpusa, povezani podaci, Lingvistički povezani otvoreni podaciChristian Chiarcos, Ranka Stanković, Maxim Ionov, Gilles Sérasset. "Bridging Computational Lexicography and Corpus Linguistics: A Query Extension for OntoLex-FrAC" in Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), Turin, 20-25 May 2024, LREC (2024)