Претрага
316 items
-
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)... in 12C with temperature increase, whereas this change was less pronounced for short-chain counterparts. δ13C values of individual normal hydrocarbons in HDPE pyrolysates are quite uni- form, ranging from −30.5‰ to −31.0‰, exhibiting almost no change with temperature (Figure 4). This is in accordance ...
... the increase in temperature, the decrease in abundance of long-chain homologues associated with the increase of short- chain n-alkanes and without a change in the content of mid-chain homologues is noticed (Table 7). Table 7. Values of Σn-alk-1-enes/Σn-alkanes ratio and values of common organic geochemical ...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
-
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... where rapid measurements are required. Figure5.1.Piezoelectric sensors 2. Piezoresistive sensors- These sensors use variable resistors that change in response to pressure. The resistors are typically made from materials such as silicon crystals. Piezoresistive sensors are highly accurate and ...
... the magnitude |a(R)|is used. However, in the case of dynamomerric charts, rotation invariance is not critical because some types of charts can change after rotation. This is the case with charts showing leakage from a moving valve at a stationary valve. In the frequency domain representation of ...
... s: Wavelet Transform allows analysis of signals in both time and frequency domains. Wavelet descriptors are effective for analyzing signals that change over time. They can be useful in recognizing short-term anomalies in the data. 3. Descriptors Without Additional Features: Research has shown that ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
-
A tool for identifying the criticality in the disordered systems with metastable dynamics
Svetislav Mijatović, Dragutin Jovković, Sanja Janićević, Stefan Graovac, Đorđe Spasojević. "A tool for identifying the criticality in the disordered systems with metastable dynamics" in Physica A: Statistical Mechanics and its Applications, Elsevier BV (2021). https://doi.org/10.1016/j.physa.2021.125883
-
Evidence for Ladinian (Middle Triassic) platform progradation in the Gyulakeszi area, Tapolca Basin, Western Hungary: Microfacies Analysis and Biostratigraphy
Zsolt Robert Nagy, Nevenka Đerić, Sándor Kovács, Anna Oravecz-Scheffer, Felicitász Velledits, Olga Piros, Gabor Csillag (2014)... 1999). During the Pelsonian (Balatonic45 ammonoid zone), synsedimentary block faulting. has caused the breakup of the uniform ramp and abrupt change in facies development (Fig. 2). Based on Budai & Veros (1992), platform carbonates (Tagyon Formation) were developed on the topographic highs ...
... were interpreted as the driving force wbhile marked increase in carbonate production is suggested to be another important parameter behind the change from aggradation to progradation (Maurer 2000). Other examples from the Western Tethys include the Sciliar episodes in Dolomites (De Zanche et ...Zsolt Robert Nagy, Nevenka Đerić, Sándor Kovács, Anna Oravecz-Scheffer, Felicitász Velledits, Olga Piros, Gabor Csillag. "Evidence for Ladinian (Middle Triassic) platform progradation in the Gyulakeszi area, Tapolca Basin, Western Hungary: Microfacies Analysis and Biostratigraphy" in Rivista Italiana di Paleontologia e Stratigrafia (2014)
-
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 ...... discharge cycle, the plunger moves toward the bottom of the cylinder. The relationship between the distance traveled by the plunger and the pressure change caused by the fluid inside the pump depends on the 8 compressibility of the fluid mixture inside the cylinder. If the fluid is nearly incompressible ...
... the small movement of the plunger cause large pressure changes. In cases where the fluid is more compressible (a mixture of gas and liquid), a change in volume is needed to decrease or increase the pressure, 1.e., to open and close the valves. This required volume can only be achieved through ...Ana Ponoćko. Design of a sucker rod pumping system, 2024
-
Regionalno-geološke karakteristike miocenskih sedimenata na prostoru severnog Banata
Dejan N. Radivojević (2014-12-30)Predmet doktorske disertacije predstavljalo je rešavanje strukturno‐stratigrafskihodnosa miocenskih sedimenata na prostoru severnog Banata. U cilju regionalnogsagledavanja, korišćeni su svi raspoloživi geofizički i geološki podaci sa širegistražnog područja, odnosno iz celog Panonskog basena i susednog orogena. Osimklasičnih metoda primenjene su i savremene metode seizmostratigrafije,tektonostratigrafije i riftne sekvencione stratigrafije. Primenjene metode omogućilesu izradu modela progradacije ivice šelfa za ceo Panonski basen, modela uzajamnihveza između basena i geodinamičkog modela jugoistočnog oboda basena.Jezero Panon je većim delom zapunjeno prilivom sedimenata paleo‐Dunavom saseverozapada, odnosno ...Centralni Paratetis, Panonski basen, miocen, jezero Panon,seizmostratigrafija, sekvenciona stratigrafija, paleogeografija, geodinamika... Global and Planetary Change, v. 103, p. 99–118. Toljić, M., L. Matenco, M. N. Ducea, U. Stojadinović, J. Milivojević, and N. Đerić, 2013, The evolution of a key segment in the Europe – Adria collision: the Fruška Gora of northern Serbia, Global and Planetary Change, v. 102, p. 39–62. T ...
... Oszczypko, D. Pavelić, F. Rögl, B. Saftić, L. Sliva, and B. Studencka, 2007, Badenian evolution of the Central Paratethys Sea: paleogeography, climate and eustatic sea‐level changes, Geologica Carpathica, v. 58/6, p. 579–606, Bratislava. Kräutner, H. G., and G. Bindea, 2002, Structural ...
... Szafián, G. Windhoffer, and S. Cloetingh, 2007, Present‐day stress field and tectonic inversion in the Pannonian Basin, Global and Planetary Change, v. 58(1–4), p. 165–180, doi:10.1016/j.gloplacha. 2007.01. 007. Badics, B., and I. Vető, 2011, Source rocks and petroleum systems in the ...Dejan N. Radivojević. "Regionalno-geološke karakteristike miocenskih sedimenata na prostoru severnog Banata" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2014-12-30)
-
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... Late Cretaceous (Campanian) carbon isotope events, sca- level change and correlation of the Tethyan and Boreal realms. Palaeogeography, Palaeoclimatology, Palaeoecol- ogy, 188: 215—248. Jenkyns, H. C., 1996. Relative sea-level change and carbon iso- topes; data from the Upper Jurassic (Oxfordian) ...
... radiolarites have been studied widely, in terms of depositional processes, bio- and chemostratigraphy as well as thcir significance to the record of climate changes (Baumgartner, 2013 and references the- rein). Correlation of regional biostratigraphic schemes often remains ambiguous, because of the ...
... Geologica Hungarica, 29: 133—149. Brigaud, B., Durlet, C., Deconinck, J.-F., Vincent, B., Pucćat, E., Thierry, J. & Trouiller, A., 2009. Facies and climate/environ- mental changes recorded on a carbonate ramp: a sedimentolo- gical and geochemical approach on Middle Jurassic carbon- ates (Paris Basin ...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)
-
Indexing of textual databases based on lexical resources: A case study for Serbian
In this paper we describe an approach to improvement of information retrieval results for large textual databases by pre-indexing documents using bag-of-words and Named Entity Recognition. The approach was applied on a database of geological projects financed by the Republic of Serbia in the last half century. Each document within this database is described by metadata, consisting of several fields such as title, domain, keywords, abstract, geographical location and the like. A bag of words was produced from these ...... curve for the first query (zlato OR Au) AND (Bor OR Borski okrug): left, retrieval wihout index; right, retrieval with index. point k, and ∆(k) is the change in recall from items k − 1 to k. The results show that for 4 queries AP was higher in the old system, while for 6 queries AP was higher in the new ...Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović. "Indexing of textual databases based on lexical resources: A case study for Serbian" in Semantic Keyword-based Search on Structured Data Sources : First COST Action IC1302 International KEYSTONE Conference, IKC 2015, Coimbra, Portugal, September 8-9, 2015. Revised Selected Papers, Springer (2015). https://doi.org/10.1007/978-3-319-27932-9_15
-
Frequency and Length of Syllables in Serbian
Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová (2019)Basic analyses of several properties of syllables (the rank-frequency distribution, the distribution of length, and the relation between length and frequency) in Serbian is presented. The syllabification algorithm used combines the maximum onset principle and the sonority hierarchy. Results indicate that syllables behave similarly to words as far as mathematical models are concerned, but values of parameters in models for syllables are quite different from those for words.... problematic for minor languages (such as e.g. Lower and Upper Sorbian among Slavic languages). In addition, the rules derived from Pulgram’s approach can change relatively quickly, as lexicon is one of the more dynamic language features. Therefore, we follow another approach, namely, a combination of the ...Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová. "Frequency and Length of Syllables in Serbian" in Glottometrics (2019)
-
Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija
Srđan D. Kostić (2013-11-04)U ovoj disertaciji, cilj istraživanja bio je određivanje dinamičkih svojstava potresaizazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija.Analiza potresa izvedena je sa dva aspekta – u prvom delu istraživanja izučavane suvremenske serije oscilovanja tla za vreme potresa, a u drugom delu vršena je analizastabilnosti fenomenološkog Baridž-Knopof modela bloka sa oprugom. Vremenske serijeoscilovanja tla proučavane su primenom postupka analize surogat podataka, kao ikorišćenjem metoda analize nelinearnih vremenskih serija (primena teoreme orazvijanju skalarne vremenske serije). Analiza vremenskih serija izvedena je ...potres, naponsko stanje, podzemne prostorije, bifurkacije, vremenskaserija, deterministički haos, stohastičnost, perturbacije, vremensko kašnjenje, jačina trenja... DYNAMICAL MODELING OF SEISMIC EVENTS INDUCED BY STRESS CHANGE DUE TO EXCAVATION OF HORIZONTAL UNDERGROUND CHAMBERS ABSTRACT In this dissertation, the aim of the research was to determine the dynamics of seismic events induced by the stress change due to excavation of horizontal underground chambers ...
... izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija;Nonlinear dynamical modeling of seismic events induced by stress change due to excavation of horizontal underground chambers Srđan D. Kostić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду ...
... izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija;Nonlinear dynamical modeling of seismic events induced by stress change due to excavation of horizontal underground chambers | Srđan D. Kostić | Универзитет у Београду | 2013-11-04 | | http://dr.rgf.bg.ac.rs/s/repo/it ...Srđan D. Kostić. "Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-11-04)
-
Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija
Srđan D. Kostić (2013-11-04)U ovoj disertaciji, cilj istraživanja bio je određivanje dinamičkih svojstava potresaizazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija.Analiza potresa izvedena je sa dva aspekta – u prvom delu istraživanja izučavane suvremenske serije oscilovanja tla za vreme potresa, a u drugom delu vršena je analizastabilnosti fenomenološkog Baridž-Knopof modela bloka sa oprugom. Vremenske serijeoscilovanja tla proučavane su primenom postupka analize surogat podataka, kao ikorišćenjem metoda analize nelinearnih vremenskih serija (primena teoreme orazvijanju skalarne vremenske serije). Analiza vremenskih serija izvedena je ...potres, naponsko stanje, podzemne prostorije, bifurkacije, vremenskaserija, deterministički haos, stohastičnost, perturbacije, vremensko kašnjenje, jačina trenja... DYNAMICAL MODELING OF SEISMIC EVENTS INDUCED BY STRESS CHANGE DUE TO EXCAVATION OF HORIZONTAL UNDERGROUND CHAMBERS ABSTRACT In this dissertation, the aim of the research was to determine the dynamics of seismic events induced by the stress change due to excavation of horizontal underground chambers ...
... izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija;Nonlinear dynamical modeling of seismic events induced by stress change due to excavation of horizontal underground chambers Srđan D. Kostić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду ...
... izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija;Nonlinear dynamical modeling of seismic events induced by stress change due to excavation of horizontal underground chambers | Srđan D. Kostić | Универзитет у Београду | 2013-11-04 | | http://dr.rgf.bg.ac.rs/s/repo/it ...Srđan D. Kostić. "Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-11-04)
-
Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content
Nina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović (2019)Mesoporous anatase nanopowders were doped with 0.05−0.5 mol% of W6, in order to obtain more efficient photocatalyst than TiO2 Degussa P25 in the degradation of amitriptyline (AMI) under simulated solar irradiation (SSI). Dominant XRPD peaks were ascribed to anatase phase, with additional peaks which could correspond to brookite, TiO2 bronze and sodium titanate, Na2Ti9O19. The Raman scattering measurements have confirmed anatase as dominant phase, with broad Raman feature at ~270 cm−1 possibly related to Ti–O–Na stretching vibration. All W-doped ...Sol-gel synthesis, Doped titania nanopowders, XRPD, Raman spectroscopy, Adsorption and photocatalytic degradation, Psychiatric drugsNina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović. "Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content" in Journal of Sol-Gel Science and Technology, Springer Science and Business Media LLC (2019). https://doi.org/10.1007/s10971-019-04925-4
-
Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides
Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor (2019)Internal Dinarides, Drina-Ivanjica thrust sheet, Deformation history, K–Ar dating, Obduction, Structural analysis... regression line (Fig. 6b) implies that the K/Ar ages become younger with a decrease of the KI values. The decrease in KI values means increase in the change of the crystal structures of the K-white mica min- erals, which is the result of increasing metamorphic degree. Based on IC measurements (Table ...
... J.. & Đerić, N. (2013). The evolution of a key segment in the Europe-Adria collision: the Fruška Gora of northern Serbia. Global and Planetary Change, 103, 39-62. Tomljenović, B., Csontos, L., Mdrton, E., & Mirton, P. (2008). Tectonic evolution of the northwestern Internal Dinarides as constrained ...Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor. "Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides" in Swiss Journal of Geosciences (2019)
-
Automatic construction of a morphological dictionary of multi-word units
The development of a comprehensive morphological dictionary of multi-word units for Serbian is a very demanding task, due to the complexity of Serbian morphology. Manual production of such a dictionary proved to be extremely time-consuming. In this paper we present a procedure that automatically produces dictionary lemmas for a given list of multi-word units. To accomplish this task the procedure relies on data in e-dictionaries of Serbian simple words, which are already well developed. We also offer an evaluation ...electronic dictionary, Serbian, morphology, inflection, multiwordn units, noun phrases, query expansion... consist of a noun followed by a component in the genitive case, but their inflectional behavior is different: in the first MWU the second component can change in number whereas in the second MWU it does not inflect. For that reason they belong to two different classes (and super- classes), nc nxn4 and nc ...Cvetana Krstev, Ranka Stanković, Ivan Obradović, Duško Vitas, Miloš Utvić. "Automatic construction of a morphological dictionary of multi-word units" in Lecture Notes in Computer Science 6233, Advances in Natural Language Processing, Proceedings of the 7thInternational Conference on NLP, IceTAL 2010, Reykjavik, Iceland, August 2010, Springer (2010): 226-237. https://doi.org/10.1007/978-3-642-14770-8_26
-
Terminology Acquisition and Description Using Lexical Resources and Local Grammars
Acquisition of new terminology from specific domains and its adequate description within terminological dictionaries is a complex task, especially for languages that are morphologically complex such as Serbian. In this paper we present an approach to solving this task semi-automatically on basis of lexical resources and local grammars developed for Serbian. Special attention is given to automatic inflectional class prediction for simple adjectives and nouns and the use of syntactic graphs for extraction of Multi-Word Unit (MWU) candidates for ...... tvrdica ica N 3 m/f + N679 40 7 18 ubica Table 1: Excerption from dataset with ending. (m: masculine gender; f: feminine gender; m/f: nouns change gender in their inflectional paradigm) Analysis of the relation between word end- ings and inflectional FST classes shows that the prediction ...Cvetana Krstev, Ranka Stanković, Ivan Obradović, Biljana Lazić. "Terminology Acquisition and Description Using Lexical Resources and Local Grammars" in Proceedings of the 11th Conference on Terminology and Artificial Intelligence, Granada, Spain, 2015, Granada : LexiCon (Universidad de Granada) (2015)
-
From DELA Based Dictionary to Leximirka Lexical Database
Biljana Lazić, Mihailo Škorić (2020)In this paper, we will present an approach in transforming Serbian language Morphological dictionaries from a DELA text format to a lexical database dubbed Leximirka. Considering the benefits of storing data within a database when compared to storing them in textual documents, we will outline some of the functionality that the database has made possible. We will also show how hand-made rules that use category labels lexical entries are marked with can be used to link lexical entries. ...... guide- lines are more appropriate for encoding traditional dictionaries intended for human use. This does not mean that the situation is not about to change, because there is an interest in linking to the Simple Knowledge Organiza- tion System (SKOS) ontologies (Declerck et al., 2010) and the Lemon model ...Biljana Lazić, Mihailo Škorić. "From DELA Based Dictionary to Leximirka Lexical Database" in Infotheca, Faculty of Philology, University of Belgrade (2020). https://doi.org/10.18485/infotheca.2019.19.2.4
-
Development and Evaluation of Three Named Entity Recognition Systems for Serbian - The Case of Personal Names
In this paper we present a rule- and lexicon-based system for the recognition of Named Entities (NE) in Serbian news paper texts that was used to prepare a gold standard annotated with personal names. It was further used to prepare training sets for four different levels of annota tion, which were further used to train two Named Entity Recognition (NER) sys tems: Stanford and spaCy. All obtained models, together with a rule- and lexicon based system were evaluated on ...... general lexica, they contain many proper names, both personal and geopolitical. The system is modular which means that steps can be omitted and can change order; however, it performs best when used in predefined way since in each step the disambiguation of some names is performed. SRPNER presented in ...Branislava Šandrih, Cvetana Krstev, Ranka Stanković. "Development and Evaluation of Three Named Entity Recognition Systems for Serbian - The Case of Personal Names" in Proceedings - Natural Language Processing in a Deep Learning World, Incoma Ltd., Shoumen, Bulgaria (2019). https://doi.org/10.26615/978-954-452-056-4_122
-
Definition of groundwater genesis and circulation conditions of the complex hydrogeological karst system Mlava–Belosavac–Belosavac-2 (eastern Serbia)
Ljiljana Vasić, Saša Milanović, Zoran Stevanović, Laszlo Palcsu. "Definition of groundwater genesis and circulation conditions of the complex hydrogeological karst system Mlava–Belosavac–Belosavac-2 (eastern Serbia)" in Carbonates and Evaporites, Springer Science and Business Media LLC (2020). https://doi.org/10.1007/s13146-020-00550-3
-
An arid phase in the Internal Dinarides during the early to middle Miocene: Inferences from Mg-clays in the Pranjani Basin (Serbia)
N. Andrić-Tomašević, V. Simić, O. Mandic, D. Životić, M. Suárez, E. García-Romero. "An arid phase in the Internal Dinarides during the early to middle Miocene: Inferences from Mg-clays in the Pranjani Basin (Serbia)" in Palaeogeography, Palaeoclimatology, Palaeoecology, Elsevier BV (2020). https://doi.org/10.1016/j.palaeo.2020.110145
-
Using Metadata For Content Indexing Within An OER Network
Ranka Stanković, Olivera Kitanović, Ivan Obradović, Roberto Linzalone, Giovanni Schiuma, Daniela Carlucci (2014)... basis of user search activity Preselected groups of resources Resource access level permissions by user group Multilingual,allowingthe user to change the languagewith most major languages supported Automatic thumbnail creation for resources Minimal hosting requirements After comparing and analysing ...Ranka Stanković, Olivera Kitanović, Ivan Obradović, Roberto Linzalone, Giovanni Schiuma, Daniela Carlucci. "Using Metadata For Content Indexing Within An OER Network" in Proceedings of the Fifth International Conference on e-Learning, eLearning 2014, September 2014, Belgrade, Serbia, Belgrade : Belgrade Metropolitan University (2014)