Претрага

Упит dcterms_subject_txt:Data mining

1236 items

  • Influence of Ag doping on the morphological and magnetic properties in CuO nanopowders

    Maria Čebela, Uroš Čakar, Vesna Lojpur, Maja Milošević, Sanja Krstić, Vladimir Dodevski, Milena Rosić (2023)
    ... у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs 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 ...
    ... Faculty of Pharmacy, Department of Bromatology, Belgrade, Serbia “Department of Mineralogy, Crystallography, Petrology and Geochemistry, Faculty of Mining and Geology, University of Belgrade, Đušina 7, 11000 Belgrade, Serbia We studied the influence of Ag doping on the crystal structure and magnetic ...

  • Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines

    Ugljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković (2022)
    This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...
    Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems Engineering

  • Correlation of uniaxial compressive strength with the dynamic elastic modulus, p –wave velocity and s –wave velocity of different rock types

    Jelena Majstorović, Miloš Gligorić, Suzana Lutovac, Milanka Negovanović, Luka Crnogorac (2019)
    Knowing mechanical properties of rocks incorporated with ultrasonic waves velocities investigations provide a secure basis for mine modelling. Uniaxial compressive strength, dynamic elastic modulus and ultrasonic waves velocities are just some of the rock properties that indicate on presence of discontinuities, stratification and fissures of rocks. Determining the relationship of these rock properties testing the rock samples that are corresponding to different rock types extracted from different mineral deposits represents the core of this study. In this paper, we ...
    линеарна регресија, метода најмањих квадрата, динамички модул еластиности, брзина уздужних таласа

  • Estimating hydraulic parameters for the complex hydrodynamic models

    Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin (2018)
    Hydrodynamic models have usually been calibrated manually, by trial-and-error, with different values of hydraulic parameters and hydraulic characteristics of boundary conditions. This method of calibration and estimation of hydraulic parameters requires an extensive knowledge and experience of experts, but whether the resulting solution includes an optimal set of parameters still remains an open question. An optimization method founded upon the Gauss-Marquardt-Levenberg algorithm, along with PEST software based on that algorithm, introduces automation of model calibration with regularization, which substantially ...
    kalibracija, optimizacija, PEST, koeficijent filtracije

  • Applicability of the risk ranking methodology designed for water reservoirs to tailings storage facilities

    Dragana Nišić, Dinko Knežević, Aleksandar Cvjetić, Neda Nišić, Vladimir Jovanović (2022)
    The risks associated with operating water reservoirs and tailings storage facilities (TSFs) are different because of their different purposes, methods of construction and operation, and characteristics of the materials impounded and their flow behaviour. Regardless of the differences, these two types of structures are often put in the same category when it comes to risk assessment and the application of relevant methodologies, which may result in unrealistic outcomes. In this paper we investigate whether it is possible to apply ...
    procena rizika, akumulacije za vodu, jalovište, TSF, ICOLD, FMEA

  • Anthropogenic impact on the groundwater regime: Case study of the Velika Morava alluvium

    Jovana Mladenović, Vesna Ristić Vakanjac, Milan Kresojević, Boris Vakanjac, Jugoslav Nikolić, Dušan Polomčić, Dragoljub Bajić (2023)
    The Velika Morava River originates at the junction of the Južna Morava and Zapadna Morava at the town of Stalać in Serbia. It is 185 km long and empties into the Danube. The Velika Morava River Basin occupies a land area of 37 444 km2. The river flows through central Serbia, which features the most fertile land and the highest population density in the country. Public water supply in this region of Serbia relies on groundwater formed in alluvial ...
    hydrology, surface water regime, groundwater regime, the Velika Morava River

  • The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje

    Boban Pavlović, Milica Pešić-Georgiadis (2019)
    In order to determine the solar energy potential for a specified location, it is crucial to consider the latitude, altitude, slope, terrain morphology, atmospheric conditions, etc. Such a complex calculation and mapping of solar energy can be done using the ArcGIS geoprocessing tool, named Area Solar Radiation (ASR). By using the ASR tool, supported with the adequate input data, it is possible to calculate the maximum solar radiation energy (irradiation) for a defined area and for a specified time ...
    Obnovljivi izvori energije, potencijal solarne energije, GIS, mapiranje solarnog potencijala
    ... 209. PBC GIS, 2019. Site Modeling in Context - Obtaining And Transforming Elevation Data, pbc Geographic Information Services, available at: http://wwWw.pbcgis.com/dem/. Republic of Serbia, Ministry of Mining and Energy, 2018. Energy balances for 2019. "Official Gazette of RS" 105 /I8, Belgrade ...
    ... When estimating the solar energy potential for the specific location, it is highly recommended to have ground measured data from the meteorological stations. Such data can provide better precision in the evaluation of the solar energy potential. However, high costs of installation and m ...
    ... 5.4 kWh / m? in Northern Serbia and 6.9 kWh / m? in Southern Serbia (University of Belgrade, 2004). It should be noted that the data were obtained based on «data measured at meteorological stations University of Belgrade, 2004). Figure 8 shows two maps with the average daily energy of solar ...

  • 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
    ... slučaju, to znači da se vektori ne smeju presecati, pošto, u suprotnom, ne bi bio ispunjen uslov o jedinstvenosti rešenja. U slučaju presecanja vektora, to bi značilo da za jednu istu tačku sistema (koja je simbolički predstavljena poljem) postoje dva rešenja – u tom slučaju, za datu tačku unutar polja ...
    ... [Brace, Byerlee, 1966] predloženo je da bi ovakvo kretanje moglo da opiše nastanak zemljotresa u Zemljinoj kori. Nedugo zatim, oslanjajući se na ove rezultate, Baridž i Knopof [Burridge,                                                          1 mine (mining) seismology (ang.) 2 stick-slip motion ...
    ... karakteristika; b) kada su blokovi povezani oprugama različitih karakteristika, pri čemu je uzeto da je krutost opruge proporcionalna zbiru masa svih blokova između opruge i slobodnog kraja. U datom opitu svi blokovi su imali masu od 142gr. Sila u oprugama u oba slučaja iznosila je 2N, pri čemu ...

  • 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
    ... slučaju, to znači da se vektori ne smeju presecati, pošto, u suprotnom, ne bi bio ispunjen uslov o jedinstvenosti rešenja. U slučaju presecanja vektora, to bi značilo da za jednu istu tačku sistema (koja je simbolički predstavljena poljem) postoje dva rešenja – u tom slučaju, za datu tačku unutar polja ...
    ... [Brace, Byerlee, 1966] predloženo je da bi ovakvo kretanje moglo da opiše nastanak zemljotresa u Zemljinoj kori. Nedugo zatim, oslanjajući se na ove rezultate, Baridž i Knopof [Burridge,                                                          1 mine (mining) seismology (ang.) 2 stick-slip motion ...
    ... karakteristika; b) kada su blokovi povezani oprugama različitih karakteristika, pri čemu je uzeto da je krutost opruge proporcionalna zbiru masa svih blokova između opruge i slobodnog kraja. U datom opitu svi blokovi su imali masu od 142gr. Sila u oprugama u oba slučaja iznosila je 2N, pri čemu ...

  • Witness of the history: A hundred years old the geological hammer of Jovan Zujovic

    Ljupko Rundić (2021)
    Током обележавања тридесет година постојања и рада Српског геолошког друштва 10. фебруара 1921. године, у знак великог поштовања према академику Јовану Жујовићу, председнику и оснивачу Српског геолошког друштва и српске геолошке школе, чланови СГД поклонили су му јединствени геолошки чекић са угравираном посветом и својим потписима. Током протеклих стотину година, многе генерације геолога проналазиле су инспирацију гледајући чекић и делећи ову причу с великим пијететом. Данас, када геолози посећују Спомен собу геологије (Рударско-геолошки факултет, ул. Каменичка бр. 6), где се пажљиво ...
    Геолошки чекић, Јован Жујовић, Српско геолошко друштво, 1921–2021

  • Hydrochemical impact of the hydraulic tunnel on groundwater in the complex aquifer system in Pirot, Serbia

    Marina Ćuk, Igor Jemcov, Ana Mladenović, Marina Čokorilo Ilić (2020)
    Hidrogeohemijski procesi, hidrohemijske promene, karstna izdan, tunel pod pritiskom, multivarijantne statističke analize

  • Град Охрид и Извештај о одржаним међународним конференцијама “SDEWES” и “BALWOIS” на Охриду (Македонија)

    Драгољуб Бајић, Јелена Зарић, Весна Ристић Вакањац, Душан Поломчић, Марина Чокорило Илић (2014)
    Представљан је рад SDEWES и BALWOIS конференције које су одржане нa Охриду. Дат је увид у рад и развој ових конференција, као и утисака и искустава учесника, представника Департмана за хидрогеологију, Рударско-Геолошког факултета. Акценат је стављен на секцију која се бави одрживим развојем водних ресурса, уз прилог о самом Охриду због његовог геолошког и хидрогеолошког значаја и чињенице да је познати туристички центар, седиште бројних конгреса и конференција из области вода, управо због своје интересантне историје и природних ...
    Охридско језеро, водни ресурси, туризам

  • Digital Library From A Domain Of Criminalistics As A Foundation For A Forensic Text Analysis

    Dalibor Vorkapić, Aleksandra Tomašević, Miljana Mladenović, Ranka Stanković, Nikola Vulović (2017)
    U ovom radu predstavljen je model koji omogućava prikupljanje, pripremu, opis metapodataka, upravljanje i eksploataciju, uključujući pretragu punog teksta dokumenata iz domena kriminalistike napisanih na srpskom jeziku. Predloženi pristup primenjuje se na veb portalu koji sakuplja različite tekstove nastale iz časopisa Akademije za kriminalistiku i policijske studije, Krivičnog zakona Srbije, konferencija „Tara“ i „Reiss“, kao i iz nekih doktorskih disertacija vezanih za ovu oblast istraživanje. Nakon obrade teksta, korpus koji sadrži preko 5500 stranica običnog teksta, kreiran je i ...
    Omeka, Wordnet, pretraga punog teksta, morfološka i semantička pretraga teksta, proširenje upita
    ... Troponymy (manner-name) is for verbs what hyponymy is for nouns. For the purpose of enriching SWN with the data concerning sentiment measurement, SentiWordNet, a lexical resource for opinion mining based on the Princeton WordNet, is used.20 It assigns three sentiment scores: positivity, negativity and ...
    ... Audience, Date Available, Bibliographic Citation, Conforms To, Date Created, Date Accepted, Date Copyrighted, Date Submitted, Audience Education Level, Extent, Has Format, Has Part, Has Version, Instructional Method, Is Format Of, Is Part Of, Is Referenced By, Is Replaced By, Is Required By, Date Issued ...
    ... Faculty of Mining and Geology Aleksandra Tomašević University of Belgrade – Faculty of Mining and Geology Miljana Mladenović PhD eVox Solutions Ranka Stanković PhD University of Belgrade – Faculty of Mining and Geology Nikola Vulović University of Belgrade – Faculty of Mining and Geology ...

  • Trace elements and garnet formation in a distal skarn zone: a case study of the Rudnik deposit, Central Serbia

    Bojan Kostić, Pavle Tančić, Natalija Batoćanin (2024)
    geohemija granata, retke zemlje, fluidne inkluzije, skarnovsko ležište Rudnik

  • Izbor rotornih bagera za proces revitalizacije: primer rotornih bagera SRs 1200 u rudarskom basenu Kolubara

    Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić, Goran Todorović, Dragan Novaković (2020)
    Revitalizacija je proces ili skup tehničkih zahvata na mašini kojim se vrši zamena svih dotrajalih ili oštećenih delova metalne konstrukcije. Sastavni deo procesa revitalizacije je i modernizacija zastarele elektro-mašinske opreme. Principi revitalizacije sasvim sigurno nisu sadržani u okviru redovnog godišnjeg ili dnevnog održavanja. Oni predstavljaju održavanje onih veličina koje su značajne za mašinu kao celinu (u ovom slučaju rotorni bager). U ovom radu su analizirani rotorni bageri oznake SRs 1200. Na površinskim kopovima rudarskog basena Kolubara takvih bagera ima ...
    Rotorni bageri, revitalizacija, SRs1200

  • Indexing of textual databases based on lexical resources: A case study for Serbian

    Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović (2015)
    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 ...
    ... archiving of geologic data, and provide a modern and effective in- formation basis for carrying out all activities related to planning, design and decision-making in the field of geology. Within the project a web portal3 was established that allows quick and easy access to geological data and information ...
    ... resources: A case study for Serbian | Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović | 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 | 2015 ...
    ... rule-based system. Both were then used for index- ing documents and ranking was based on tf idf measure. Evaluation of ranked retrieval results based on data obtained by pre-indexing are com- pared to results obtained by informational retrieval without pre-indexing with Precision-Recall Curve, showing a ...

  • Using technology for knowledge transfer between academia and enterprises

    Ivan Obradović, Ranka Stanković (2014)
    ... within enterprises that generates expert knowledge. Although higher education institutions (HEI) endeavor towards keeping academic curricula up-to-date with novel entrepreneurial knowledge, this has become a critical issue, especially in engineering disciplines. Technological development generates ...
    ... university students' knowledge with entrepreneurial knowledge that might prove useful in their future jobs, to keeping their academic knowledge up-to-date once they have graduated, by offering them a live-long learning opportunity as employees. There are, however, several critical issues, which might ...
    ... у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs 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 ...

  • Geochemical study of U, Th and REE mineralizations in Jurassic sediments and hydrochemical characterization of groundwaters in Eastern Serbia – Case study: Plavna area

    Jovan Kovačević, Maja Todorović, Marina Ćuk, Petar Papić (2016)
    jurski sedimenti, uran, torijum, elementi retkih zemalja, podzemna voda, istočna Srbija

  • Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization

    Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić (2016)

  • 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.
    frekvencije slogova, dužina slogova, srpski jezik
    ... full data can be found at rgf.rs/projekti/bil/sk/results/KakoSeKalioCelik_2019 _01_14.xlsx) can be modelled by one of these distributions as well. Table 2. Rank-frequency distribution of syllables in Serbian rank frequency syllable 1 10103 o 2 6970 je 3 5778 u 4 5291 na 5 5248 da 6 4827 ...
    ... normalization constant). As several other Poisson-like distributions also fit the data very well, we postpone any attempts to formulate conclusions that could be deduced from the model and parameter values until data for more languages are available. Stretching the analogy between words and syllables ...
    ... University of Novi Sad, Trg Dositeja Obradovića 6, 21101 Novi Sad, Serbia, and Faculty of Mining and Geology, University of Belgrade, Đušina 7, 11120 Beograd, Serbia e-mail: marija.radojicic@uns.ac.rs 2 Faculty of Mining and Geology, University of Belgrade, Đušina 7, 11120 Beograd, Serbia e-mail: biljana ...