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621 items
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Challenges in using wastewater heat pumps in district heating systems
Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović, Dimitrije Manić (2022)Decarbonization of district heating systems requires ensuring significant amounts of renewable energy available in the proximity of the district heating network. One of the promising solutions is the utilization of purified water from wastewater treatment plants by heat pumps. However, as a heat source, wastewater treatment plants are characterized by annual variability of the flow and temperature of purified water. The consequence is the variability of recoverable heat potential. In this paper, the effect of variability is analyzed for ...Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović, Dimitrije Manić. "Challenges in using wastewater heat pumps in district heating systems" in 20th International Conference on Thermal Science and Engineering of Serbia, Niš, Serbia, October 18 – 21, 2022, Faculty of Mechanical Engineering in Niš (2022)
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Building Terminological Resources in an e-Learning Environment
... of Mining and Geology [11]. The Faculty started with this implementation by developing its own FMG CMS (Course Management System) as the core of the blended learning system at FMG. In 2009, following an initiative of a number of teachers and teaching assistants, the introduction of Moodle FMG CMS ...
... terms has been recognized several years ago. Namely, various applications developed in this area followed by the development of an information system for planning, monitoring and management of mine exploitation, indicated that such resources would greatly contribute to their functionality [5]. ...
... becoming the reference resource for mining terminology in Serbian in e-format. RudOnto is presently implemented within a mining engineering information system, which has previously also been developed at FMG. Although it has reached a considerable size to date, it is still being intensively enlarged and ...Ranka Stanković, Ivan Obradović, Olivera Kitanović, Ljiljana Kolonja. "Building Terminological Resources in an e-Learning Environment" in Proceedings of the Third International Conference on e-Learning, eLearning-2012, September 2012, Belgrade, Serbia, Belgrade : Belgrade Metropolitan University (2012)
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Development of Open Educational Resources (OER) for Natural Language Processing
In this paper we present the development of an online course at the edX BAEKTEL platform named “Lexical Recognition in the Natural Language Processing (NLP)”. It is based on the course of the same name for PhD studies at the University of Belgrade, Faculty of Philology. There are not many courses in Computational Linguistics (CL) on OER platforms, and there is none in Serbian either for CL or NLP. We have developed this course in order to improve this ...... The course participant will become familiar with the use of Unitex, the corpus processing system for which many valuable resources for Serbian have already been developed. Unitex 11 is an open source system consisting of a collection of programs developed for text analysis by using linguistic ...
... linguistics and computer scientists developing NLP applications. The participant will become familiar with the use of Unitex, the corpus processing system for which many valuable resources for Serbian were already developed. This course covers a broad range of topics such as pattern recognition using ...
... project of its OER version within the edX BAEKTEL platform. 2 The main features of Unitex, an open access and open source corpus processing system, are presented in Section 4. Section 5 presents course content with didactic criteria and specific formats used in the OER course. Concluding ...Cvetana Krstev, Biljana Lazić, Ranka Stanković, Giovanni Schiuma, Miladin Kotorčević. "Development of Open Educational Resources (OER) for Natural Language Processing" in The Sixth International Conference on e-Learning (eLearning-2015), September 2015, Belgrade, Serbia, Belgrade : Belgrade Metropolitan Univesity (2015)
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A WordNet Ontology in Improving Searches of Digital Dialect Dictionary
In this paper, we present a method for automatic generation of a digital resource, which connects all indirect synonyms of a dialect term to all indirect synonyms of a corresponding term in the standard language, aiming to improve the search of a digital dialect dictionary. The method uses SWRL rules defined in the Serbian WordNet ontology to identify sets of synonymous words. It also uses e-dictionaries to produce correct lemmas in standard language that users usually employ in searches. ...... 897. Table 1. The confusion matrix of the process deciding whether dictionary entries are correctly aligned with standard language entries. System Yes | System No Expert yes tp = 3022 fn = 436 Expert no fp=0 tn = 784 We can notice that the proposed method is completely precise, but the prob- lem with ...
... classification, compared results obtained from the system with data provided by humans. The accuracy measure was acc=89.7%. In future work, we will experi- ment with other parts of speech and we will try to expand the set of ontological rules used in this system. View publication statsView publication stats ...
... for search. The method was applied and evaluated on verbs and a group of nouns derived from verbs (verbal nouns). We compared results obtained by the system with those produced by humans and achieved the accuracy of 89.7%. Keywords: dialect dictionary, ontology, WordNet, e-dictionary, South Serbian dialect ...Miljana Mladenović, Ranka Stanković, Cvetana Krstev. "A WordNet Ontology in Improving Searches of Digital Dialect Dictionary" in New Trends in Databases and Information Systems: ADBIS 2017 Short Papers and Workshops - SW4CH (Semantic Web for Cultural Heritage) 767, Springer International Publishing (2017). https://doi.org/10.1007/978-3-319-67162-8_37
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Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households
The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed. These two systems represent two different types of individual wood biomass heating systems. In the case of the firewood-based heating systems, it is analyzed a typical stove ...... les/2015-07/documents/emission-factors_2014.pdf https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system-models-in-ecoinvent-3.html ...
... -07/documents/emission- factors_2014.pdf (accessed 25 Sept. 2020.) [24] Ecoinvent, Ecoinvent 3.0. System Models in ecoinvent 3.https://www.ecoinvent.org/database/system-models-in-ecoinvent-3/system- models-in-ecoinvent-3.html (accessed 30 Sept. 2020). https://www.pre-sustainability.com/legacy ...
... Dejan Ivezić. Marija Živković 430 However, since LCA considers the environmental aspects and the potential impacts of a product or a service system throughout its life, it becomes a very useful method for researching studies related to the problem of sustainable development, cleaner production ...Boban Pavlović, Dejan Ivezić, Marija Živković. "Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households" in 5th International Scientific Conference ”Conference on Mechanical Engineering Technologies and Applications” COMETa2020, East Sarajevo, 2020, University of East Sarajevo, Faculty of Mechanical Engineering East Sarajevo (2020)
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A comparative study of the molecular and isotopic composition of biomarkers in immature oil shale (Aleksinac deposit, Serbia) and its liquid pyrolysis products (open and closed systems)
Gordana Gajica, Aleksandra Šajnović, Ksenija Stojanović, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević (2021)The molecular and isotopic composition of biomarkers in initial bitumen isolated from immature (0.41% Rr) oil shale samples (Aleksinac deposit) and liquid products obtained by pyrolysis in open (OS) and closed (CS) systems are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in liquid products is determined. The applicability of pyrolysis type, numerous biomarkers and carbon isotopic compositions (δ13C) of n-alkanes in liquid pyrolysates is established. Pyrolysis experiments were ...Uljni šejl, Aleksinac, organska supstanca, otvoreni i zatvoreni sistem pirolize, biomarkeri, izotopski sastav ugljjenikaGordana Gajica, Aleksandra Šajnović, Ksenija Stojanović, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević. "A comparative study of the molecular and isotopic composition of biomarkers in immature oil shale (Aleksinac deposit, Serbia) and its liquid pyrolysis products (open and closed systems)" in Marine and Petroleum Geology, Elsevier BV (2021). https://doi.org/10.1016/j.marpetgeo.2021.105383
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Advantages and challenges in presenting mathematical content using EDX platform
... partners from industry [5]. The idea of the project was to establish a system for creating, publishing, maintaining and searching of OERs both from academic institutions and enterprises. An important part of this system is the Open edX platform, which was adapted for the needs of BAEKTEL project ...
... required, which http://tpack.org/ inform the system that there is a mathematic formula (Image 5). MathJax presents a cross-browser JavaScript library that displays mathematical notation in web browsers using LaTex document preparation system. Image 5: Example of tasks editing ...
... progress [6]. Experts stress the importance of using TPACK framework (Image 4) in creating mathematical content. TPACK has been presented as a system which interconnects and intersects technology, pedagogy, and content knowledge [7]. According to this model technological knowledge has an important ...Marija Radojičić, Ivan Obradović, Ranka Stanković, Olivera Kitanović, Roberto Linzalone. "Advantages and challenges in presenting mathematical content using EDX platform" in The Seventh International Conference on e-Learning (eLearning-2016), Belgrade : Metropolitan University (2016)
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Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal
Ivan Kojić, Achim Bechtel, Nikoleta Aleksić, Dragana Životić, Snežana Trifunović, Gordana Gajica, Ksenija Stojanović (2021)... 500 ◦C. 3.2. The Yields of Pyrolysis Products Obtained by Open System Pyrolysis The yields of pyrolysis products obtained by open system pyrolysis are given in Table 1. Table 1. The yields of pyrolysis products obtained in open system pyrolysis and differences between experimental and theoretical ...
... the open system at 400 oC (b), 450 oC (c) and 500 oC (d)., Figure S2: TICs of liquid products obtained by HDPE pyrolysis in the open system at 400 oC (a), 450 oC (b) and 500 oC (c), Figure S3: TICs of aliphatic fractions of liquid products obtained by lignite/HDPE co-pyrolysis in the open system at 400 ...
... of liquid products obtained by pyrolysis in the open system at 500 oC; lignite (a), HDPE (b), lignite/HDPE mixture (c), Figure S5: TICs of aromatic fractions of lignite EOM (a), and liquid products obtained by lignite pyrolysis in the open system at 400 oC (b), 450 oC (c) and 500 oC (d), Figure S6: TICs ...Ivan Kojić, Achim Bechtel, Nikoleta Aleksić, Dragana Životić, Snežana Trifunović, Gordana Gajica, Ksenija Stojanović. "Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal" in Polymers, MDPI AG (2021). https://doi.org/10.3390/polym13050759
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Challenges of Energy Transition in the Individual Heating Sector
U radu su prikazani rezultati istraživanja i ankete koja je sprovedena 2020. godine u domaćinstvima sa individualnim sistemima grejanja u Srbiji. Cilj ankete je bio da se sagleda stanje individualnih sistema grejanja, ali i stavovi vlasnika sistema vezano za energetsku tranziciju. Rezultati ukazuju na zastarelost sistema grejanja, nisku efikasnost, nedovoljna ulaganja u primenu mera energetske efikasnosti i nedostatak finansijskih sredstava za ulaganje u održivo grejanje. Osnovni prioriteti kod izbora načina grejanja jesu troškovi kupovine sistema i troškovi energenta, dok ...Boban Pavlović, Dejan Ivezić, Marija Živković. "Challenges of Energy Transition in the Individual Heating Sector" in Energija, ekonomija, ekologija, University Library in Kragujevac (2022). https://doi.org/10.46793/EEE22-1.17P
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Against the tide: southeast to northwest shelf-edge progradation in the southeastern margin of Lake Pannon, Banat (Serbia and Romania)
In the late Neogene, the Pannonian Basin in Central Europe was filled with sediments when rivers from the Alps and Carpathians shed their sediment load into Lake Pannon. The most powerful source-to-sink system was that of the paleo-Danube, transporting sediments from the NW as far as the southeastern part of the lake. In the southeastern margin of the basin, however, local sedimentary systems worked in the opposite direction, against the “tide” of the prevailing N to S sediment transport. ...Dejan Radivojević, Miloš Radonjić, Lajos Tamás Katona, Imre Magyar. "Against the tide: southeast to northwest shelf-edge progradation in the southeastern margin of Lake Pannon, Banat (Serbia and Romania)" in International Journal of Earth Sciences, Springer Science and Business Media LLC (2022). https://doi.org/10.1007/s00531-022-02188-z
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To what extent reactivated faults are (not) responsible for karst process: example from Serbian Carpatho-Balkanides?
Ana Mladenović, Jelena Ćalić (2023)Carpatho-Balkanides represent part of the complex Dinaric – Carpatho – Balkan orogenic system, that geomorphologically dominates the central part of the Balkan Peninsula. The existence of this orogenic system is a result of closure of the Neotethys ocean and subsequent convergence of the Adriatic microplate and the Eurasian continent, that has been still active in the recent times. Such geodynamic characteristics conditioned complex tectonic structures, multiply reactivated during Late Cretaceous and Cenozoic times. The main aim of this work ...Ana Mladenović, Jelena Ćalić. "To what extent reactivated faults are (not) responsible for karst process: example from Serbian Carpatho-Balkanides?" in Abstracts and Guide Book 30th International Karstological School "Classical Karst" Karst - Approaches and Conceptual Models, Ljubljana : Scientific Research Centre of the Slovenian Academy of Sciences and Arts (ZRC SAZU), Karst Research Institute (2023)
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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 ...... Availability of energy System availability index (N-1) indicating the daily operational flexibility, which describes the daily operational flexibility of the gas pipeline system, as well as the ability of the system to respond to consumption requirements in extreme conditions. System availability index ...
... distribution and distribution system operation are performed by 32 licensed distribution system operators. Most of them are owned by municipalities and towns, some of them are public-private partnership, and some of them are private companies [71]. The current transmission system has the capacity to transport ...
... level of availability of the natural gas (S1) can be accessed by the (N-1) system availability index [2]. N-1 index describes the daily operational flexibility of the gas pipeline system, as well as the ability of the system to respond to consumption requirements in extreme conditions and it is calculated ...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
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Hypogene speleogenesis related to porphyry magmatic intrusions and its influence on subsequent karst evolution in the Peruvian high Andes
Alexander Klimchouk, David Evans, Sasa Milanovic, Cristian Bittencourt, Mauro Sanchez, F. Carlos Aguirre (2022)Alexander Klimchouk, David Evans, Sasa Milanovic, Cristian Bittencourt, Mauro Sanchez, F. Carlos Aguirre. "Hypogene speleogenesis related to porphyry magmatic intrusions and its influence on subsequent karst evolution in the Peruvian high Andes" in Geomorphology, Elsevier BV (2022). https://doi.org/10.1016/j.geomorph.2022.108488
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The lost freshwater goby fish fauna (Teleostei, Gobiidae) from the early Miocene of Klinci (Serbia)
Freshwater gobies played an important role in the Miocene paleolakes of central and southeastern Europe. Much data have been gathered from isolated otoliths, but articulated skeletons are relatively rare. Here, we review a rich assemblage of articulated gobies with abundant otoliths in situ from the late early Miocene lake deposits of Klinci in the Valjevo freshwater lake of the Valjevo-Mionica Basin of Serbia. The fauna was originally described by Anđelković in 1978, who noted many different fishes, including one ...Katarina Bradić-Milinović, Harald Ahnelt, Ljupko Rundić, Werner Schwarzhans. "The lost freshwater goby fish fauna (Teleostei, Gobiidae) from the early Miocene of Klinci (Serbia)" in Swiss Journal of Palaeontology, Springer Science and Business Media LLC (2019). https://doi.org/10.1007/s13358-019-00194-4
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Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support
Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović. "Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support" in Journal of Vibroengineering (2017). https://doi.org/10.21595/jve.2016.17321
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Effectiveness Analysis of Different Bucket-wheel Excavators
Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić. "Effectiveness Analysis of Different Bucket-wheel Excavators" in 8th International Conference Mining and Environmental Protection, Sokobanja, 22-25 September 2021, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2021)
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The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers
One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...... is used [2, 5]. Life cycle of a machine, facility or any other technical system has a complex structure, and it encompasses several distinctive but interrelated and timely adjusted groups of activities. Technical system is used only during one part of own life cycle, therefore, time it is used is ...
... machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity ш таноп ој the continuous system јог the excavatioh ој coal апа tailings, which indicafes their importance. More than 100 bulldozers have been hired оп the ореп-сазт lignite mines ...
... machines (bucket wheel excavators, belt conveyors and stackers). It also should be noted that one hour of bucket wheel excavator — belt conveyor — stacker system operation is valued at several thousands of euros, and that value on one hour of dozer operation is below 100 €. Hence, it is more important that open-cast ...Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović. "The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers" in 7th International Symposium Mining and Environmental Protection, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2019)
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Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic
Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković (2020)Artificial lift methods have applications in oil wells where oil production is no longer possible due to natural reservoir energy, so this necessary energy is added by introducing lift methods. In order to achieve optimum production, the selection of an artificial lift method is very important. This paper uses fuzzy logic as a mathematical and conceptual model for selection of the optimal artificial lift method. The outcome or IF-THEN rules, as the central part of the model, is based ...... 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), with regard to j-class as a synonym of measurement for the observed ...
... 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), with regard to j-class as a synonym of measurement for the observed ...
... April 2015. 27. Aliyev, E. Development of Expert System for Artificial Lift Selection. Master’s Thesis, Middle East Technical University, Ankara, Turkey, February 2013. 28. Bowles, J.B.; Peláez, C.E. Fuzzy logic prioritization of failures in a system failure mode, effects and criticality analysis. ...Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković. "Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic" in Energies, MDPI AG (2020)
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Linearization of Input Signal as a Necessary Tool in Stochastic Modeling of Karst Groundwater
Veljko Marinović (2021)Modelling of karst hydrogeological systems is a very complicated task, bearing in mind that for a deterministic model one should know the internal physical processes of precipitation transformation into discharge, while for a stochastic model nonlinear dynamic systems such as karst should be simulated by linear regression equations. Stochastic models need linearization of input time series due to often large residual in the recession period. This occur because the model is not able to absorb single rain episodes, which ...Veljko Marinović. "Linearization of Input Signal as a Necessary Tool in Stochastic Modeling of Karst Groundwater" in Karst: From Top to Bottom, Belgrade, 6.6.2021., Belgrade : Centre for Karst Hydrogeology (2021)
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Hydrochemical indicators of groundwater flow in the area of “Čukaru Peki” Cu-Au underground mine in eastern Serbia
The physical and chemical properties of groundwater, together with the groundwater levels regime and rock hydraulic properties, are often used to understand and conceptualize the hydrogeological system. Prediction of the influence of mining works on groundwater, and vice versa, is a challenge due to significantly altered groundwater flow patterns in the raw materials exploitation areas in relation to natural conditions. Therefore, multiple parameters are assessed and monitored before and during exploitation to properly characterize and quantify the system for ...Nebojša Atanacković, Vladimir Živanović, Jana Štrbački, Veselin Dragišić, Ivana Cvejić. "Hydrochemical indicators of groundwater flow in the area of “Čukaru Peki” Cu-Au underground mine in eastern Serbia" in 5th IAH CEG conference, Slovenian Committee of International Association of Hydrogeologists - SKIAH (2022)