Претрага
260 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... accurate monitoring of operating conditions. Typical rod pump automation includes instrumentation with load cells and position sensors, a pump shut-off control device, a control panel, and a motor drive, and in some cases, a variable-speed drive. Additionally, a radio for receiving and sending i ...
... error analysis Figure 4.2 Machine learning approach If spammers notice that your filter blocks messages containing the word "Your" in the subject line, they might start using the phrase "For You" to bypass the filter. In a traditional programming approach, you would need to manually add new rules ...
... downhole dynamometric card. Examples of these patterns for operating conditions on surface and downhole dynamometric cards are shown in Figure 6.1. Line card Noise card Surface card Dovmnhole card Downhole card Surface card 6000 4000 ~ı M\ s s a) š 2000 0 5 10 15 20 25 30 b) š -4000 WAAWF@@JW{ ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
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OER obrazovni sadržaji kao spona između akademskog i preduzetničkog znanja
... može se reći da ova platforma ne zahteva visok stepen računarskih veština. Sam postupak kreiranja kursa je relativno jednostavan, a postoji i on line podrška u vidu tutorijala. Da bi korisnik kreirao edX kurs u okviru BAEKTEL projekta neophodno je da pristupi web adresi: http://edx.baektel.eu:18010 ...Ivan Obradović, Ranka Stanković, Marija Radojičić. "OER obrazovni sadržaji kao spona između akademskog i preduzetničkog znanja" in The fifth Symposium Mathematics and Applications 2014,17-18 October 2014, Belgrade V no. 1, Beograd : Matematički fakultet Univerziteta u Beogradu (2014)
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Using Lexical Resources for Irony and Sarcasm Classification
The paper presents a language dependent model for classification of statements into ironic and non-ironic. The model uses various language resources: morphological dictionaries, sentiment lexicon, lexicon of markers and a WordNet based ontology. This approach uses various features: antonymous pairs obtained using the reasoning rules over the Serbian WordNet ontology (R), antonymous pairs in which one member has positive sentiment polarity (PPR), polarity of positive sentiment words (PSP), ordered sequence of sentiment tags (OSA), Part-of-Speech tags of words (POS) ...... “figuratively” [14]. Authors in [29] used a microblogging platform called Plurk, similar to Twitter, to create a corpus of ironic statements. Other on- line resources can also be used for ironic corpus creation – Google Books search was used in the work by [21], where the phrase “said sarcastically” was ...
... te ni promaja ne bi udarila ‘you are so ugly that even the draught wouldn’t hit you’. 5.2 The application of the irony classifier to sarcasm A thin line divides ironic utterances from sarcastic ones. There are many definitions and comparisons of these two figures. According to one of themost comprehensive ...Miljana Mladenović, Cvetana Krstev, Jelena Mitrović, Ranka Stanković. "Using Lexical Resources for Irony and Sarcasm Classification" in Proceedings of the 8th Balkan Conference in Informatics (BCI '17), New York, NY, USA, : ACM (2017). https://doi.org/
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Application of stochastic models for mine planning and coal quality control
... power plants [2]. However, decisions about coal homogenization must deal with uncertainty and variability in coal properties, and with the effect of off-design coal characteristics on power plant performance and cost. According to Shih and Frey [3] sulfur and ash content and heating value are considered ...
... 1 if that point is in the polygon and value 0 if the point is out of the polygon. This function can be calculated by taking an arbitrary ray (half-line) from the point that inter- sects the sides of the polygon. If the number of intersections is even, then the value of the func- tion is 0, and if ...
... According simulated daily or shift mine plan each BWE has working bench position and pro- duction parameters. Mass and quality control will be done by on-line devices and weightmeters on main belt conveyor. If coal quality has required values coal is transported directly to thermal power plant, if not coal ...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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Determination of the groundwater-leakage mechanism (binary mixing) in a karstic dam site using thermometry and isotope approach (HPP Visegrad, Bosnia, and Herzegovina)
Earth-Surface Processes,Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeLjiljana Vasić, Saša Milanović, Anita Puskás-Preszner, Laszlo Palcsu. "Determination of the groundwater-leakage mechanism (binary mixing) in a karstic dam site using thermometry and isotope approach (HPP Visegrad, Bosnia, and Herzegovina)" in Environmental Earth Sciences, Springer Science and Business Media LLC (2020). https://doi.org/10.1007/s12665-020-08910-x
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Legal framework for recultivation of degraded areas caused by mining exploitation
Radmila Gaćina (2023)Prilikom površinske i podzemne eksploatacije uglja eksploatacioni sistemi oštećuju veće ili manje površine zemljišta. Iskustva pokazuju da su oštećenja zemljišta znatno veća kod površinske eksploatacije, gde je prostora degradiran ne samo u konturi rudnika i okoline, već se promene takođe dešavaju u prirodnom okruženju. U članku su predstavljeni rezultati studije zakonskih okvira rekultivacije u nekim zemljama sveta i u Srbiji. Praktično iskustvo rekultivacije pokazalo je da iskorišćenje i devastacija tokom rudarske aktivnosti predstavljaju opasnost ne samo za pogođena ...... include: reclaimed land area, surface cover thickness, ground slope and drainage function, the physical and chemical properties of the soil are in line with the standards of arable land, and the failure to meet the acceptance criteria, should not pass the acceptance (Guo at all, 2022). After the ...Radmila Gaćina. "Legal framework for recultivation of degraded areas caused by mining exploitation" in Underground mining engineering, Belgrade : University of Belgrade - Faculty of Mining and Geology (2023). https://doi.org/10.5937/podrad2342027G
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Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules
The stability analysis of homogeneous rock slope following the Hoek–Brown failure criterion under the hypothesis of different flow rules is performed based on limit equilibrium and finite element methods. The applied failure criterion is the generalized Hoek–Brown that can be introduced as a shear/normal function in analysis applying different flow rules. The results are compared with those obtained by the application of equivalent shear strength parameters of the Mohr–Coulomb criterion, considering that this is still the most widely used ...Kružna klizna površ, Huk-Braunov kriterijum loma, Kriterijum popuštanja, Smičuća/normalna funkcija, Nivo napona, Verovatnoća i parametarska analizaSvetlana Melentijević, Zoran Berisavljević, Dušan Berisavljević, Claudio Olalla Marañón . "Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules" in Bulletin of Engineering Geology and the Environment , Springer (2024). https://doi.org/10.1007/s10064-024-03667-0
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Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia
... fewer features, this model offers the added benefit of a 55% reduction in computation time. In this instance, it may be beneficial to make a trade-off by selecting a model that is statistically inferior but yields satis- factory visual outcomes, while requiring 55% less computa- tional time. This ...
... extent of known faults in the area, while the Euclidian AlI the obtained data was transformed to the MGI Bal- Distance tool calculates the straight-line distance from cach — kans Zone 7 projected coordinate system. The target varia- pixel to the nearest fault. The resulting raster map can be — ble ...
... 10 km RF_C_100_5MI Fig.9 RE model with only five most informative features (RF_C_100_5MI); n- number of ophiolite class instances; black out- line- field mapped ophiolites; red markers- predicted ophiolites of the C dataset models. In general, the RF_C_100_5MI model exhibits comparable prediction ...Filip Arnaut, Dragana Đurić, Uroš Đurić, Mileva Samardžić-Petrović, Igor Peshevski. "Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia" in Earth Science Informatics, Springer Science and Business Media LLC (2024). https://doi.org/10.1007/s12145-024-01243-4
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The number of unimodular roots of some reciprocal polynomials
Dragan Stankov (2020)We introduce a sequence P2n of monic reciprocal polynomials with integer coefficients having the central coefficients fixed. We prove that the ratio between number of nonunimodular roots of P2n and its degree d has a limit when d tends to infinity. We present an algorithm for calculation the limit and a numerical method for its approximation. If P2n is the sum of a fixed number of monomials we determine the central coefficients such that the ratio has the minimal limit. ...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. "The number of unimodular roots of some reciprocal polynomials" in Cmptes rendus mathematique (2020). https://doi.org/10.5802/crmath.28
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Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian
Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek. "Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian" in Language and Text: Data, models, information and applications, John Benjamins Publishing Company (2021). https://doi.org/10.1075/cilt.356.04ruj
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Coal homogenization stockyard sizing “Tamnava – Zapad” case study
... gray lines show the different simulations. The bottom and top dotted lines show the minimum and maximum simulated values, while the middle dotted line is the arithmetic mean of the simulations. Figure 1. Number of coal stacking layers at the "Tamnava - Zapad" pit as a function of standard ...Božo Kolonja, Dinko Knežević, Ranka Stanković, Dejan Stevanović, Detlef Trummer. "Coal homogenization stockyard sizing “Tamnava – Zapad” case study" in Proceedings of 13th International Symposium Continuous Surface Mining, ISCSM 2016, / (2016)
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Approach to operational mine planning: Case study Tamnava West
... for black coal utilization, Callaghan 5 Galetakis M, Pavloudakis F, 2009, The effect of lignite quality variation on the efficiency of on-line ash analyzers, International Journal of Coal Geology, vol. 80, pp. 145-156 6 Beretta F, Costa J, Koppe J, Souza V, 2009, Reducing coal quality ...Dejan Stevanović, Mirjana Banković, Milica Pešić Georgiadis, Ranka Stanković. "Approach to operational mine planning: Case study Tamnava West" in Tehnika, Beograd : Savez inženjera i tehničara Srbije (2014). https://doi.org/10.5937/tehnika1406952S
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GNSS Time Series as a Tool for Seismic Activity Analysis Related to Infrastructure Utilities
Sanja Tucikešić, Ankica Milinković, Branko Božić, Ivana Vasiljević, Mladen Slijepčević . "GNSS Time Series as a Tool for Seismic Activity Analysis Related to Infrastructure Utilities" in Contributions to International Conferences on Engineering Surveying. Springer Proceedings in Earth and Environmental Sciences, Dubrovnik, Croatia, October 22-23, 2020, Springer, Cham (2021). https://doi.org/10.1007/978-3-030-51953-7_21
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Evidence of Variscan and Alpine tectonics in the structural and thermochronological record of the central Serbo-Macedonian Massif (south-eastern Serbia)
... 1991; Ricou 1994; Schmid et al. 2008; Stampfli and Hochard 2009). Therefore, to reveal the tectonic evolution of these intra-Alpine crystal- line units, their complex structural patterns need to be stud- led in detail together with determination of age of their pro- toliths and timing of ...
... cleavage Ss. These axes are generally plunging in the south-western quadrant (Fig. 4b). Kinematic indicators such as shear bands, polycrystal- line sigmoids, and asymmetric clasts on outcrops, as well as biotite fish in thin sections, were observed in the XZ plane and indicate generally top ...
... (T')) and Lower Complex gneiss (G) in the Slatinska Reka Valley (22%1'30.716”E, 42%0'"%53.365"N). Trace of the contact plane is indicated by black line. S, foliation formed during D, and folded into isoclinal folds F»; S» axial-plane cleavage related to folds F, during D,. Length of ham- mer ca ...Milorad D. Antić, Alexandre Kounov, Branislav Trivić, Richard Spikings, Andreas Wetzel. "Evidence of Variscan and Alpine tectonics in the structural and thermochronological record of the central Serbo-Macedonian Massif (south-eastern Serbia)" in International Journal of Earth Sciences, Springer Science and Business Media LLC (2016). https://doi.org/10.1007/s00531-016-1380-6
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Генеза хидротермалног Cu-Au система Чукару Пеки (Источна Србија)
Милош Велојић (2021)Главни циљ испитивања хидротермалног система Чукару Пеки је разумевање процеса који су довели до његовог настанка, а посебно еволуције рудоносних флуида из којих је настала рудна минерализација. Утврђено је да је овај систем настао у периоду пре 86,78 - 85,19 Ma из магматског интрузива који је био богат водом и имао висок оксидативни потенцијал. Током хлађења, из овог магматског интрузива су издвојени веома врели флуиди, који су имали температуре изнад 600°С и висок салинитет. У ...Борска металогенетска зона, Тимочки магматски комплекс, порфирска лежишта, високосулфидациона лежишта, флуидне инклузије, рудне парагенезе, геохронологија, хидротермалне алтерације, LA-ICP-MS... Укупно (%) Line spectrum(1) 0,00 53,71 0,41 45,88 100 Line spectrum(2) 0,08 52,86 0,00 47,05 100 Line spectrum (3) 0,12 53,17 0,00 46,71 100 Line spectrum (4) 0,08 53,31 0,00 46,61 100 Line spectrum (5) 0,15 53,17 0,00 46,69 100 Line spectrum (6) 0,09 53,27 0,00 46,64 100 Line spectrum (7) ...
... O Na Si S Ca Fe Cu Укупно Line Spectrum(1) 0,00 50,64 0,11 41,79 7,46 100,00 Line Spectum(2) 0,09 52,78 0,00 46,88 0,24 100,00 Line Spectrum(3) 5,81 0,29 0,18 42,44 0,42 50,11 0,75 100,00 Line Spectrum(4) 0,22 53,64 0,00 45,84 0,30 100,00 Line Spectrum(5) 0,14 52,14 0,00 ...Милош Велојић. Генеза хидротермалног Cu-Au система Чукару Пеки (Источна Србија), Београд : [М. Велојић], 2021
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Towards translation of educational resources using GIZA++
... in English. Thus a growing need for translating MOOC content. The solutions provided so far have been fragmentary, human-based, and implemented off-line by the majority of course providers. [2] TraMOOC (Translation for Massive Open Online Courses) is a Horizon 2020 collaborative project aiming ...Ivan Obradović, Dalibor Vorkapić, Ranka Stanković, Nikola Vulović, Miladin Kotorčević. "Towards translation of educational resources using GIZA++" in The Seventh International Conference on e-Learning (eLearning-2016), September 2016, Belgrade : Metropolitan Univesity (2016)
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Quantitative landslide risk assessment in the city of Tuzla
In the climate-changing conditions, geological environment interacts more dramatically with the urban fabric than before. The urbanization is expansive and more aggressive than before, but so are the weather extremes and long-term climate trends. In effect, many processes which can be triggered by either side, nature or engineering, are becoming more pervasive than before, and such is the case with landslides. Dealing and managing landslides requires few crucial steps, starting from collecting data on landslide location and typology – ...... to hydrographic network, i.e. streams and rivers which were also extracted from DTM as vector lines. Subsequently, Euclidean distance from this line vector was calculated for each pixel in the area of interest. All these represent numeric variables, which were further normalized to 0-1 range. ...Miloš Marjanović, Biljana Abolmasov, Cvjetko Sandić, Miralem Mulać, Petar Begović. "Quantitative landslide risk assessment in the city of Tuzla" 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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Control of substructure construction of railways in the Republic of Serbia
Контрола збијености природног тла (у ископу) или збијеног у насипу при изградњи саобраћајница представља један од основних облика контроле квалитета доњег строја. Код изградње брзих саобраћајница (аутопутеви и брза железница) приоритет је постизање високог нивоа контроле извршених радова. У циљу онемогућавања диференцијалног слегања (при изградњи насипа), или промене запремине услед допунског збијања материјала, које неминовно доводе до деформација, потребно је извршити оптимално збијање материјала. У оквиру овог рада приказује се техничка регулатива која регулише контролу збијености при изградњи железничке ...... same height profile, so the obtained results cannot be compared by layers. This practice of compaction control and substructure construction is not in line with existing regulations. The consequences of such tests often lead to the degradation of the substructure, which results in the need to repair and ...Dragan Lukić, Dragoslav Rakić, Irena Basarić Ikodinović. "Control of substructure construction of railways in the Republic of Serbia" in International Conference On Contemporary Theory and Practice in Construction XV, Banja Luka 16-17 jun 2022., University of Banja Luka Faculty of Architecture, Civil Engineering and Geodesy (2022)
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Inhibitory effect of platinum and ruthenium bipyridyl complexes on porcine pancreatic phospholipase A2
Tina Kamčeva, Jörg Flemmig, Bojana Damnjanović, Jürgen Arnhold, Aleksandar Mijatović, Marijana Petković (2011)Fosfolipaza pankreasa A2 (PLA2) igra važnu ulogu u ćelijskoj homeostazi kao iu procesu karcinogeneze. Efekti metalo-lekova koji se koriste kao hemoterapeutici na aktivnost ovog enzima nisu poznati. U ovom radu, interakcija između PLA2 svinjskog pankreasa i dva odabrana kompleksa prelaznih metala — tetrahloro(bipiridin) platine(IV) ([PtCl4(bipi)]) i dihloro (bipiridin) rutenijum(III)hlorida ([RuCl2(bipi)2) ]Cl)—proučavana je. Laserska desorpcija/jonizacija uz pomoć matriksa, vremenska masa spektrometrija (MALDI-TOF MS) i fluorescentna spektroskopija korišćeni su za analizu aktivnosti enzima u odsustvu i prisustvu metalnih kompleksa i za ...... proliferation, invasion and metastasis.11–13 Several studies have shown that human pancreatic PLA2 stimulates the growth of a human pancreatic cancer cell line via binding to a specific receptor.9,14 It also stimulates extracellular matrix invasion by normal and cancer cells.15 In addition, this enzyme is ...
... the tryptophan fluorescence of PLA2 by [RuCl2(bipy)2]Cl is given in Fig. 6B. At low metal complex concentrations, data can be fitted to a straight line, but there is a clear deviation at higher concentrations. Thus, the ruthenium metal complex causes both a dynamic and static quenching. In other words ...Tina Kamčeva, Jörg Flemmig, Bojana Damnjanović, Jürgen Arnhold, Aleksandar Mijatović, Marijana Petković. "Inhibitory effect of platinum and ruthenium bipyridyl complexes on porcine pancreatic phospholipase A2" in Metallomics, Oxford University Press (OUP) (2011). https://doi.org/10.1039/c1mt00088h
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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 ...Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović. "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae" in Organic Geochemistry, Elsevier BV (2019). https://doi.org/10.1016/j.orggeochem.2019.01.001