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Упит dcterms_subject_txt:Data analysis

764 items

  • Evaluation And Perspectives Of Underground Coal Mines In Serbia

    Vladimir Milisavljević, Milena Lekić, Ivica Ristović, Vojin Čokorilo, Aleksandar Cvjetić (2017)
    ... cvjetic@rgf.bg.ac.rs Summary: This paper provides analysis of mines operating in Public Company for Underground Coal Exploitation (PCUCE), which is in restructuring process in excess of 10 years. Evaluation of these mines included analysis of performance and development potential of eight mines ...
    ... (Headquarters in Resavica). Operation and performances of PCUCE were evaluated and analyzed on several occasions in previous years. Most notable analysis were [2], during which PCUCE was a part of JP EPS, and [3], study financed by European Agency for Reconstruction whose beneficiary was Ministry ...
    ... Conclusion Public Company for Underground Coal Exploitation operates 8 mines and one company working as a contractor at other mines. AHP analysis, based on technical criteria, identified two groups of mines, one with potential for further development (Soko, Strmosten pit- REMBAS, Lubnica ...

  • Geostatički proračuni sanacije klizišta šipovima

    Slobodan Ćorić, Dragoslav Rakić, Dušan Berisavljević (2019)
    U ovom radu su, polazeći od rezultata geotehničkih istraživanja, prikazani geostatički proračuni sanacije klizišta vertikalnim šipovima. Metodologija proračuna je složena, jer podrazumeva interakciju klizišta i stabilizirajućih šipova. Stoga se simultano analiziraju stabilnost klizišta i stabilnost šipova. Prilikom određivanja bočne otpornosti tla oko šipova koristi se metoda Brinč Hansena koja uzima u obzir trodimenzionalne uslove u tlu i može da se primeni u složenim geološkim uslovima koji su česti u Srbiji. Analize stabilnosti klizišta vrše se odgovarajućim metodama granične ravnoteže. ...
    sanacija klizišta, interakcija klizišta i šipa, bočna otpornost šipova, stabilnost klizišta i šipova
    ... postupku projektovanja sanacionih mera, potrebno da se izvrši simultana analiza stabilnosti ih šipova je trodimenzionalni problem i stabilnosti klizišta. 300 U radu su prikazani svi elementi koji predloženu m LITERATURA: Chandler, R.J.: Back analysis techniques for slope stabilization works: a ...
    ... complex, because it is based on the interaction between landslide and stability piles. In accordance to that, landslide stability analysis and pile stability analysis are carried out simultaneously.The lateral resistance of piles is calculated by Brinch Hansen method. It includes three-dimensional ...
    ... povratnom analizom može da se odredi prosečna čvrstoća smicanja duž klizne površine tla uay (Slika 4), а u slučaju reaktiviranja starih klizišta, na ovaj način se određuje rezidualna čvrstoća (Chandler, 1977). Slika 4. Površina klizanja Figure 4. Sliding surface 297 mogu da se provere vrednosti ...

  • Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta

    Aleksandar Pačevski (2022)
    ... Ag in this pyrite were determined by the microprobe analysis methods of a mineral composition (EMPA and LA-ICP-MS). However, using the microprobe analysis methods of a crystal structure of mineral, such as micro-Raman spectroscopy and TEM analysis with prior sample preparation by Focused Ion Beam (FIB) ...
    ... laserskom ablacijom (eng. LA-JCP-M5S) ı druge slične metode daju istraživaču u ruke veoma „„moćno oružje“. Međutim, ukoliko se ovakvo oružje samo i malo pogrešno usmeri dobija se niz pogrešnih interpretacija i zaključaka koji mogu veoma da štete samom istraživanju. Pravilnu upotrebu savremenih metoda ...
    ... determination: trends and achievements Miloš Marjanović, Analiza odrona u stenskim kosinama: savremeni pristupi Miloš Marjanović, Rockfalls analysis in rock slopes: state-of-the-art approaches Aleksandar Pačevski, Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta ...

  • 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
    ... are: 1. Data monitoring and analysis Sensors can collect data on various aspects of pump operation, such as pressure, flow rate, vibrations, temperature, and sounds. This data can be highly complex and encompass large amounts of information. Machine learning can analyze these data to identify ...
    ... algorithms can use real-time data to predict potential failures before they occur. For instance, if certain patterns in the data are identified as precursors to a failure, the system can alert the need for maintenance before a serious issue arises. Based on data analysis, machine learning can help ...
    ... Fourier Transform, moment analysis, and other techniques to recognize key patterns in the data. These descriptors allow conversion of complex data into a format that is easier to analyze and interpret. 51 5.Use in Diagnostics: Extracted features are used for further analysis to identify potential ...

  • 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 ...
    mehaničke metode, proizvodnja nafte, fazi logika, donošenje odluka, optimizacija
    ... of multicriteria analysis: TOPSIS, ELECTRE, SAW and VIKOR, in the case of oil fields in Iran. The authors used multiple sets of input data: restrictions on production, deposits and wells; characteristics of production fluid, and surface infrastructure. Cross-Sectional Analysis of Presented Research ...
    ... created by applying multi-criteria analysis (TOPSIS, ELECTRE, SAW and VIKOR). Based on the known parameters, the expert gives estimates of the input data for the optimization model, and the output is the most suitable artificial lift method [11–14]. The analysis of the mathematical and conceptual ...
    ... well in Salman oil field in Iran has been chosen as a test well. The Salman oil field data are given in Table 4. Selection of mentioned method was done using an optimization model based on a multi-criteria analysis, specifically using the ELECTRE method [12]. The exploitation methods for application ...

  • Prilog poznavanju režima i bilansa voda reke Resave

    Marina Mitrašinović, Vesna Ristić Vakanjac, Saša Milanović, Ljiljana Vasić, Dušan Polomčić (2022)
    Sliv Resave zauzima područje između reke Velike Morave i obronaka Kučajsko-beljaničkih planina. Sliv i režim ove reke kontroliše se dvema hidrološkim stanicama: Manastir Manasija (slivno područje u iznosu od 388 km2) i Svilajnac (681 km2). Za potrebe analize režima voda reke Resave i uticaja padavina na formiranje oticaja sa njenog sliva preuzeti su podaci o padavinama sa meteorološke stanice Crni Vrh (1037 m nm) koji odslikava režim gornjeg dela sliva ove reke, i meteorološke stanice Smederevska ...
    Hidrogeološke karakteristike, hidrološke karakteristike, režim voda bilans voda, rijeka Resava

  • Assessment of the Geotouristic Values of Devil’s Town, Serbia

    Danijela Vukoičić, Danica Srećković-Batoćanin, Aleksandar Valjarević, Dušan Ristić, Milena Nikolić, Dragana Valjarević (2021)
    Geotouriyam, Geonasledje, M-GAM, Komparativna analiya, Đavolja Varoš, Peščane piramide, Stob Piramide, Melnik piramide, Srbija

  • The efficiency of chemical cleaning of different metal artefacts from Felix Romuliana and Gradina archaeological sites (Serbia)

    Slobodan Bogojević, Kristina Šarić, Bojan Kostić, Suzana Erić (2022)
    SEM-EDS analiza, metalni arheološki predmeti, korozija, konzervacija

  • Hybrid Stochastic-Grey Model to Forecast the Behavior of Metal Price in the Mining Industry

    Zoran Gligorić, Miloš Gligorić, Dževdet Halilović, Čedomir Beljić, Katarina Urošević (2020)
    cena metala, neodređenosti, prognoza, stohastički sivi model, singularna analiza spektra

  • 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 (2017)

  • Laboratory testing of fly ash

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    Fly ash is one of the most common waste materials created by burning of coal. It is composed of smaller particles, consisting mainly of aluminosilicate glass, mullite and quartz, which are collected by electrostatic separators (filter) of gaseous products arising from the combustion of coal. This paper presents the pozzolanic properties, mechanical properties, chemical and mineral composition of fly ash obtained in the combustion process in a power plant Nikola Tesla A (PPNT A) with the addition of a ...
    chemical composition, fly ash, mechanical properties, mineral properties, pozzolanic properties, X-ray diffraction
    ... 725-739. DOI: 10.2298/JSC120716125I [4] SRPS B.H8.359. Methods of analysis of coal and coke - Determination of chemical composition of fuel ash - General requirements. // Belgrade (1973). [5] SRPS B.H8.360. Methods of analysis of coal and coke - Determination of silica (SiO2) in ash from solid ...
    ... solid fuels. // Belgrade (1973). [6] SRPS B.H8.361. Methods of analysis of coal and coke - Determination of barium oxide (BaO) in ash from solid fuels. // Belgrade (1973). [7] SRPS B.H8.362. Methods of analysis of coal and coke - Determination of ferric oxide (Fe2O3) in ash from solid fuels. // ...
    ... // Belgrade (1973). [8] SRPS B.H8.363. Methods of analysis of coal and coke - Determination of titanium oxide (TiO2) in ash from solid fuels. // Belgrade (1973). [9] SRPS B.H8.364. Methods of analysis of coal and coke- Determination of aluminum oxide (Al2O3) in ash from solid fuels. // Belgrade ...

  • Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu

    Marija D. Prekajski (2014-04-04)
    Nanoprahovi kristalnih faza iz serije čvrstih rastvora u pseudo-binarnom sistemuCeO2-Bi2O3 sintetisani su primenom jednostavne i ekonomične samopropagirajućemetode na sobnoj temperaturi korišćenjem nitrata metala i natrijum-hidroksida kaopolaznih supstanci. Osim krajnjih članova niza, CeO2 i niskotemperaturne polimorfnemodifikacije α-Bi2O3, sintetisani su i čvrsti rastvori nominalnog sastava Ce1-xBixO2-δ,gde je x = 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9. Rezultati proučavanja metodomrendgenske difraktometrije na polikristalnom materijalu i ramanske spektroskopskeanalize pokazali su da su sintetisani prahovi sa nižim sadržajem bizmuta (x = 0,1 ...
    nanostrukturni materijali, čvrsti rastvori, CeO2, Bi2O3, rendgenskadifraktometrija praha, Ritveldova metoda, mikrostrukrurna analiza

  • 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

    Filip Arnaut, Dragana Đurić, Uroš Đurić, Mileva Samardžić-Petrović, Igor Peshevski (2024)
    General Earth and Planetary Sciences
    ... total of 328 560 sam- pling data points. On the other hand, the testing area covered 2000 km? and comprised 201 254 sampling data points, as indicated in Table 2. Three distinct sets, cach comprising different proportions of training samples, were chosen for analysis. These sets were labeled as ...
    ... completely balanced C dataset, despite hav- ing the least amount of data for model training compared to other input data groups, yields the best overall outcomes for predictive ophiolite mapping. Feature importance analysis The RF model, which was trained on the C dataset and con- sisted of ...
    ... visual analysis of prediction maps. The methods applied in this research can be applied for predictive mapping of complex geo-tectonic units covered by dense vegetation, and may indicate the presence of these units even if they were not previously mapped, particularly when geophysical data are used ...

  • New insights into tectonic relations between the Eastern Vardar Ophiolitic and Serbo-Macedonian units: Inferences from a microtectonic study in central Serbia

    Maja Maleš, Nikola Ranđelović, Nemanja Krstekanić, Bojan Kostić, Nikolina Ćirić, Uroš Stojadinović (2023)
    Источно-вардарски офиолити, Српско-македонска јединица, микротектонска анализа, каснојурска обдукција, пост-обдукционе деформације

  • Аутоматска екстракција дефиниција – допринос убрзању израде речника

    Рада Стијовић, Цветана Крстев, Ранка Станковић (2021)
    дескриптивни речници, метаанализа лексикографских дефиниција, аутоматска екстракција дефиниција, електронски речници, српски језик

  • Mine ventilation system planning using genetic algorithms

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    The most common problem in contemporary mining practice related to the planning and analysis of ventilation systems is the optimization of partially regulated air distribution in mine ventilation networks. This paper presents a two step optimization procedure for partly regulated air distribution in mine ventilation networks. The first step is the determination of air distribution in all branches using the well known Hardy-Cross method. In the second step the distribution and parameters of air flow regulators with minimum engaged ...
    coal, lignite, and peat; ventilation systems; coal mining; underground mining; ventilation; mathematical models; design; air flow; optimization; calculation methods

  • Geotechnical conditions of “Debelo brdo” tunnel construction on the highway E-80: Nis-Merdare-Pristina (“Peace Highway”)

    Dragoslav Rakić, Irena Basarić Ikodinović, Radojica Lapčević, Dragan Lukić (2024)
    The construction of the highway E-80 has begun in Serbia, which will represent the traffic hub of the Western Balkans and will be part of the main regional transport network of Southeast Europe. Its total length through Serbia is 77 km, and one part of the route is designed through a typical plain terrain, while a larger part of the route passes through hilly terrain. The construction of the tunnel “Debelo brdo” is planned partly in an open cut ...
    „Debelo brdo“ tunnel, temporary slopes, open cut excavation, tunnel excavation, piles

  • A multi-criteria approach for assessing the potential of renewable energy sources for electricity generation: Case Serbia

    Boban Pavlović, Dejan Ivezić, Marija Živković (2021)
    When assessing the potential of renewable energy alternatives for electricity generation, it is necessary to implement a multi-perspective approach that includes economic, technical, environmental, and socio-political criteria. For the evaluation of criteria and alternatives, the Fuzzy Analytical Hierarchy Process (FAHP) method is applied. The obtained weights are formed according to the values of energy indicators and expert judgments. The use of a fuzzy numerical value scale for the assessment of expert judgments and energy indicators provides a more sensitive ...
    Proizvodnja električne energije, Obnovljivi izvori energije, Višekriterijumsko odlučivanje, Srbija
    ... and national and international data which deals with the quantitative and qualitative analysis of the utilization of RES for electricity generation. In the parts of the presented assess- ment for which there are no reference data from governmental and expert bodies, data from expert assessments and studies ...
    ... This requires further work in collecting and analyzing data from the relevant locations. The presented approach shows that the problem of research is multidimensional coupled with the lack of information, so it is not feasible to conduct analysis using a method limited exclusively to the evaluation of ...
    ... energy technical potential, geospatial data science. available at: https://www.nrel.gov/gis/re- potential.html. Energy Community, 2020. Serbia’s 2020 implementation performance and key energy sector benchmark data. available at: https://www.energy- community.org/dam/jcr:486fedf4-ed5f-4e3f-b995-5d5829b ...

  • Landscapes and Landforms in the Toplica region (Southern Serbia)

    Aleksandar Valjarević, Natalija Batoćanin, Danica Srećković-Batoćanin, Tin Lukić (2022)
    U radu je prikazano 11 geomorfoloških oblika koji zaslužuju naziv objekata geonasledja. Rad razmatra genezu objekata, neophodnost geokonzervacije, tamo gde još nije pokrenuta, i položaj i distribuciua objekata unutar zona različitog turističkog interesovanja primenom metoda daljinske detekcije, terenskih osmatranja i geografskog informacionog sistema (GIS) .
    Toplica, GIS, analiza, geomorfološki objekat, objekat geonasledja, geneza, erozija

  • Using Lexical Resources for Irony and Sarcasm Classification

    Miljana Mladenović, Cvetana Krstev, Jelena Mitrović, Ranka Stanković (2017)
    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) ...
    ... The role of expressive signals and ensemble classifiers. In Data Science and Advanced Analytics (DSAA), 2015. 36678 2015. IEEE International Conference on. IEEE, 1–8. [13] Elena Filatova. 2012. Irony and Sarcasm: Corpus Generation and Analysis Using Crowdsourcing. In 8th LREC. 392–398. [14] Aniruddha ...
    ... is used more and more in NLP tasks, primarily for advancement of sentiment analysis systems, machine translation, authorship attribution, but also for systems analyzing linguistic structures at different levels – e.g. analysis of sentiment classification results in comments published on newspaper web ...
    ... Philipp Cimiano, and Roman Klinger. 2014. An impact analysis of features in a classification approach to irony detection in product reviews. In Proc. of the 5th Workshop on Computational Approaches to Subjectivity, Sentiment and Social Media Analysis (WASSA) – 52th ACL. 42–49. [7] John D Campbell and ...