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Упит dcterms_subject_txt:scenarios of development

2846 items

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    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 ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... Liebherr in terms of R, with grades "good" in extent of 40% and “average” in extent of 60%; M as "average" in extent of 100% and S as "adequate" in extent of 100%; machine Dressta as "average" in all terms and Caterpillar as "good" in terms of R and S and "excellent" in term of M. This can be written ...
    ... 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 ...
    ... Industry of Serbia Kostolac, Serbia radisa.duric@te-ko.rs Predrag Jovancic Faculty of Mining and Geology University of Belgrade Belgrade, Serbia predrag.jovancic@rgf.bg.ac.rs Abstract—Each technical system within itself carries the great potential danger of possible occurrence of failure ...

  • The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines

    Krstev Cvetana, Stanković Ranka, Vitas Duško, Obradović Ivan (2008)
    In this paper we present how resources and tools developed within the Human Language Technology Group at the University of Belgrade can be used for tuning queries before submitting them to a web search engine. We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic ...
    LR web services, MultiWord Expressions & Collocations, Information Extraction, Information Retrieval
    ... repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs The Usage of Various Lexical Resources and Tools to Improve the Performance of Web ...
    ... brief description of resources is given, followed by an outline of the web tool which enables their integration. Finally, a set of examples is chosen in order to illustrate the use of the lexical resources and tool in question. Results obtained for these examples show that the number of documents obtained ...
    ... Ranka Stanković2 , Duško Vitas 3 , Ivan Obradović4 1 professor, Faculty of Philology, Belgrade, 2 assistant, Faculty of Mining and Geology, Belgrade 3 professor, Faculty of Mathematics, Belgrade, 4 professor, Faculty of Mining and Geology, Belgrade E-mail: cvetana@matf.bg.ac.yu, ranka@rgf.bg.ac ...

  • A hundred years of Milutin Milanković's climate change theory - geological implications

    Dejan Radivojević (2020)
    Миланковићева теорија циклуса објављена пре сто година је најважнија теорија у наукама које проучавају климу и имала је велики утицај на дисциплине које се баве Земљом. Ипак, његов рад је чекао више од педесет година да би добио потврду. Може се рећи да Миланковићев рад највећи утицај на геологију има у изради астрономске временске скале, подршци хипотези континенталног дрифта и палеоклиматологији. Добри резултати примене астрономске временске скале на неогене седименте иницирали су примену ове методе у мезозојским и у последње ...
    циклостратиграфија, астономска временска скала, геолошка временска скала, климатске промене, континентални дрифт
    ... ’s work supported one of the most important theories in geoscience ever (continental drift) and contri - buted to understanding of climate in the geological past. His work on climate changes represents the core for climate modeling which allows prediction of possible scenarios awaiting us. Having this ...
    ... only potentially noticeable in climate records of several to tens of millions of years. The Milanković’s cycles are the basis of cy- clostratigraphy, one of the youngest stratigraphic A hundred years of Milutin Milanković’s climate change theory – geological implications Geol. an. Balk. poluos., 2020 ...
    ... National Research Council of the U.S. National Academy of Sciences has embraced the model of Milanković’s Cycles. Earth climate changes - past and future Milanković’s cycles provided an understanding of the last ice age and are used for explanation of cli- mate changes of the geological past. The planet ...

  • Depth estimation of archeological objects using Euler 3D deconvolution of magnetic data

    Vesna Cvetkov, Ilija Vasiljević, Mirko Petković (2015)

  • 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
    ... The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs University of Belgrade Faculty of Mining and Geology Master ...
    ... stroke length of the smooth rod. Key structural components of the horsehead include the balance beam, the connecting rod (cam mechanism), the adjustment rod, counterweights, a gearbox, and a driving electric motor. The length of the adjustment rod, number of strokes, and the stroke length of the smooth ...
    ... Operation cycle of the downhole pump 2.3 Importance of efficient pump operation Frequent changes in pump operation and fluid composition lead to variations in the load and energy consumption of the system. Based on the physical characteristics of the well and measured values of load and smooth ...

  • Mio-Pliocene Geodynamics and its Stratigraphic Consequences in the Area of Avala Mt. (Belgrade, Serbia)

    Ljupko Rundić, Meri Ganić, Slobodan Knežević, Dejan Radivojević (2017)
    ... shaped today’s relief of the area (MAROVIĆ et al., 2007). °e Torlak hill repre- sents horst structure with a core of Mesozoic rocks and wings made of Badenian and Sarmatian sediments (EREMIJA, 1977; STEVANOVIĆ, 1970). Downstream of the Avala – Belgrade road, in the middle course of the Rakovica stream ...
    ... The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 57 7th International Workshop | Neogene of Central and South-Eastern ...
    ... , №16-05-01032) and RSF (№17-17-01146). GREBENYUK, L.V. (2004): Magnetostratigraphy of Neogene sediments of the Southern European Russia and the Pre-Caucasus. Unpubl. PhD °esis, Faculty of Geology, University of Saratov, 181 p. HILGEN, F.J., LOURENS, L.J. & VAN DAM, J.A. (2012): °e Neogene Period ...

  • Insights into dike nucleation and eruption dynamics from high-resolution seismic imaging of magmatic system at the East Pacific Rise

    Milena Marjanović, Suzanne M. Carbotte, Alexandre Stopin, Satish C. Singh, René-Édouard Plessix, Miloš Marjanović, Mladen R. Nedimović, Juan Pablo Canales, Hélène D. Carton, John C. Mutter, Javier Escartín (2023)
    Multidisciplinary

  • Introduction to special section: Characterization of hydrocarbon and geothermal resource potential and carbon sequestration opportunities of the Pannonian Basin

    Balázs Németh, Gábor Tari, Gábor Bada, Dejan Radivojević, Bruno Tomljenovic, Csaba Krézsek (2018)
    нафтна геологија, геотермална енергија, Панонски басен

  • Design of a sucker rod pumping system

    Ana Ponoćko (2024)
    For a long time in the history of oil production, sucker rod pumps have been the first and in many cases the only choice when it comes to mechanical extraction methods. Proper selection of each individual element of the system enables optimization, which entails benefits in the form of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... enable the optimization of existing designs and the assessment of the impact of future changes in system parameters. Once a system model is calibrated with real fluid data, Prosper can be confidently used to model the well under various scenarios and make forward predictions of reservoir pressure based ...
    ... the lifting of sand, the application of this type of pump is recommended because the pump body seals in the upper part with its seating, preventing the accumulation of sand between the tubing and the cylinder in case of a pump shutdown. On the other hand, a drawback of this type of top seating ...
    ... purpose of this paper is to introduce the basic components of the pump, its operation, and improvements to its performance through the application of a double-acting valve. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the ...

  • Extreme Rainfall Event and Its Aftermath Analysis—IPL 210 Project Progress Report

    Biljana Abolmasov, Mileva Samardžić Petrović, Ranka Stanković, Miloš Marjanović, Jelka Krušić, Uroš Đurić (2021)
    Landslides, Extreme precipitation, Data analysis, IPL project report

  • Reconstruction of the Tethys' waning in the Balkans: New insights from Upper Cretaceous igneous formations and zircon provenance data

    Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković (2024)
    geochronology, zircon, provenance
    ... Congress of Geologists of the Republic of North Macedonia RECONSTRUCTION OF THE TETHYS' WANING IN THE BALKANS: NEW INSIGHTS FROM UPPER-CRETACEOUS IGNEOUS FORMATIONS AND ZIRCON PROVENANCE DATA Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković University of Belgrade ...
    ... histories of these regions. The presence of Permotriassic zircons in thc Upper Cretaceous sediments of the Sava-Vardar Zone and thcir absence further cast challenge the notion of a vast Sava (Tethys) Ocean during the Cretaceous. ACKNOWLEDGEMENT This research is financed by the Science Fund of Serbia ...
    ... [ДР РГФ] Reconstruction of the Tethys' waning in the Balkans: New insights from Upper Cretaceous igneous formations and zircon provenance data | Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković | Fifth Congress of Geologists of the Republic of North Macedonia | 2024 | ...

  • Molecular and Isotope Composition of Biomarkers in Immature Oil Shale and its Liquid Pyrolysis Products (Open and Closed System)

    Gordana Gajica, Aleksandra Šajnovic, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević, Ksenija Stojanović (2021)
    The molecular and isotopic composition of biomarkers in initial bitumen isolated from raw immature oil shale samples from the Lower Miocene Aleksinac Basin (Serbia) and liquid products (LPs) obtained by pyrolysis in open (OS) and closed systems (CS) are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in LPs is determined. The molecular composition of the LPs from the OS pyrolysis is very similar to those in initial bitumen, independently ...
    ... obtained by the OS and the CS pyrolysis. The distribution of n-alkanes (C14–C35) in LPs differs from those in bitumen of raw samples, which is reflected through the increase of lower homologues. In addition to the fact that the distribution of n-alkanes depends on maturity changes that particularly ...
    ... material. The prevalence of lower homologues in LPs is consistent with the predominantly algal origin of organic matter (OM) (Gajica et al., 2017). The n-alkane distributions in all LPs are characterized by uniform abundances of odd and even homologues, resulting in a reduction of the CPI values (~ 1) ...
    ... initial bitumen of both raw samples, the pristane/phytane (Pr/Ph) ratio is similar (< 0.4). In LPs from the OS the values of Pr/Ph are 1.23 and 1.74. That might be explained by a preferred release of pristane than phytane from isoprenoid moieties during slight thermal treatment of kerogen (Larter ...

  • Distribution of major and trace elements in the Kovin lignite (Serbia)

    Dragana Životić, Olga Cvetković, Predrag Vulić, Ivan Gržetić, Vladimir Simić, Konstantin Ilijević, Biljana Dojčinović, Suzana Erić, Bogdan Radić, Sanja Stojadinović, Snežana Trifunović (2019)
    geochemical and mineralogical study was performed on lignite samples from the Upper Miocene Kovin deposit, hosting three coal seams. The Kovin lignite is characterized by high moisture content, medium to high ash yield, medium to high sulphur content and a relatively low gross and net calorific value. The mineralogical composition, and major and trace element contents were determined by X-ray diffraction, scanning electron microscopy with energy dispersive Xray spectroscopy (SEM-EDS) analyses, and inductively coupled plasma optical emission spectrometry (ICP-OES). ...
    General Earth and Planetary Sciences, General Environmental Science
    ... B.H8.317:1988, (1988): Methods of analysis of coal and coke ­ Determination of volatile matter content.– Institute for Standardization of Serbia, Belgrade, Serbia, 6 p. (in Serbian). SRPS B.H8.318:1972, (1972): Methods of analysis of coal and coke ­ Determination of gross calorific value by the ...
    ... central part of Serbia. The total thickness of Neogene sediments is estimated at 1000 m. The Neogene units of the Kovin deposit Figure 1. Location of the Kovin deposit (a, b) and simplified geological map (c) of the Kovin deposit with sample locations (modified after Basic Geologic Map of Ser- bia, section ...
    ... lignites. A large proportion of the Fe­oxide/hydroxides in the Kovin lignite samp­ les (Fig. 4h) is probably the result of the weathering of iron­rich minerals such as pyrite and siderite. A small proportion of these minerals might also be of detrital origin. Limonite (a mixture of goethite, lepidocrocite ...

  • Karst aquifer impact on the formation of surface runoff: case study of the Resava River catchment, Serbia

    Marina Mitrašinović, Vesna Ristić Vakanjac, Veljko Marinović, Saša Milanović, Ljiljana Vasić, Dušan Polomčić (2022)
    The paper compares the flow regimes of the Resava River at the gauging stations of the Manasija Monastery (upper course) and the town of Svilajnac (lower course). The hydrological analysis encompasses a multiyear period of monitoring (1982–2020). The water budget and baseflow index are assessed for the catchment areas monitored by the Svilajnac station (683 km2) and the Manasija Monastery station (358k m2), considering the overall monitoring period and characteristic years. The results indicate that the specific runoff in ...
    hydrogeological characteristics, water regime, water balance, karst aquifer, Resava catchment area
    ... the ratio of mcean annual discharges is 1:1.25 (2001) and even lower in 2018 (1:1.15). The ratio of the catchment areas covered by the gauging stations is 1:1.75. This sug- gests that most of the discharge of the Resava River is formed in the upper catchment (Figs. 1a,b). In the case of the char ...
    ... Resava catchment is in the northern part of East- ern Serbia, between the Velika Morava River and the slopes of the Kučaj-Beljanica Mountains. The Resava River originates at the junction of the Zlots- ka River and the Karapandžin Creek at an altıtude of 668 m. It is a major right-side tributary ...
    ... clevation is 93 m. The upper catchment of the Resava is a composite valley comprised of gorg- es, ravines, and canyons (mostly karst), which cn- ters the Velika Morava River Basin near the town of Despotovac (Paunković, 1953). The upper Resava runs from the village of Strmosten in the west and ('C ...

  • Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes

    Nevenka Gligorijević, Aleksandar Mijatović, Sandra Aranđelović, Rada Baošić (2021)
    Istraživanje kompleksa bakra kao potencijalnih antikancerogenih agenasa nudi ohrabrujuće perspektive u odnosu na komplekse platine (II) računajući na smanjenu toksičnost, novi mehanizam delovanja, različit spektar aktivnosti i perspektivu neunakrsne rezistencije. Kompleksi Šifovih baza bakra(II) koji sadrže tetradentatne ligande acac2en tipa (acac2en (1); tfacac2en (3), acactfacacen (4), acacphacacen (6)) pokazali su važnu antioksidativnu aktivnost, visok potencijal za interakciju sa HSA i DNK, u prethodnim studijama. Zbog toga je bilo interesantno ispitati i uporediti potencijal antikancerogene aktivnosti in vitro, u odnosu ...
    Bakar(II) kompleksi, citotoksičnost, ćelijski ciklus

  • Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian

    Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)
    slogovi, distribucija rang-preciznost, slovenski jezici

  • 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 polynomials

  • Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae

    Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović (2019)
    Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMRspectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10?20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270?146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant ...
    Geochemistry and Petrology

  • Complex geophysical survey on solving the problem of water loss in the karst terrain reservoir

    Branislav Sretković, Dejan Vučković (2023)
    Geophysical surveys in karst terrain are always a specific challenge. Each of them requires a careful consideration of the problem, specific conditions on the ground, the selection of adequate methods applicable in that specific and unique karst area. But they should have one thing in common: a complex approach and looking at the problem from wider to narrower, with a gradual narrowing of the investigation area, increasing the spatial precision and resolution of the obtained data. On the example of ...

  • From post-disaster landslides inventory to open landslides data

    Biljana Abolmasov, Miloš Marjanović, Uroš Đurić, Jelka Krušić (2021)