Претрага

Упит dcterms_subject_txt:data mining

1223 items

  • Optimizacija parametara reza rotornog bagera pri otkopavanju materijala sa povećanom čvrstoćom

    Saša D. Bošković (2016-09-09)
    Otkopavanje materijala rotornim bagerom je veoma sloţen fiziĉko-mehaniĉki proces. Pokazatelji efektivnosti tog procesa zavise od velikog broja raznovrsnih ĉinilaca od kojih se posebno mogu istaći: fiziĉko-mehaniĉke karakteristike materijala koji se otkopava, reţim rada bagera i izbor tehnoloških parametara bloka, odreska i reza, geometrije vedrica i zuba itd. Poseban problem se javlja kod otkopavanja materijala povećane ĉvrstoće, što je ĉest sluĉaj na našim površinskim kopovima. Dimenzionisanje specifiĉne sile kopanja bagera prema manjim masama izuzetno ĉvrstog materijala je neracionalno i rešenje ...
    rotorni bager, parametri reza, otpor na kopanje, dinamika bagera, kapacitet, optimizacija, specifična potrošnja energije
    ... (odreska). Uticaj promene radijusa kopanja u granicama, ustanovljenim za dati tip bagera, bio bi neznatan. To znaĉi da je proraĉun koeficijenta (kč) moguć primenom konstantnog radijusa kopanja, što odgovara srednjoj vrednosti za dati tip bagera. Boĉna rezna ivica vedrice pravi luk radijusa rv i pra ...
    ... 39,14 Rezultati ispitivanja mineralnog sastava su pokazali da testirana otkrivka nije abrazivna. Ipak je izvršen eksperiment i uporeĊivanje uzorka sa drugim materijalima, kako bi se proverio i procenio nivo abrazije, a rezultati su dati u Tabeli 2.6. Tabela 2.6. Abrazivnost ispitivanih uzoraka ...
    ... materijalom treba da bude  = 90. To je teško ostvariti ali je moguće ako se pravac pomeranja rotora seĉe sa pravcem radnog pokreta vedrice u momentu kontakta sa materijalom, baš u taĉki koja predstavlja momenat kontakta sa materijalom, jer u tom trenutku njihove tangente u datoj taĉki meĊusobno ...

  • Преносници снаге на рударским машинама

    Предраг Јованчић, Стеван Ђенадић (2023)
    Рударске машине

  • Језички модели, шта је то?

    Ми­ха­и­ло Шко­рић (2023)
    Језички модели

  • Model inteligentnog sistema adaptivnog upravljanja procesom prerade rude

    Ivana M. Jovanović (2016-01-13)
    U oblasti procesa prerade rude, flotacijska koncentracija predstavlja jednu od najznačajnijih i najčešće primenjivanih metoda separacije korisnih od nekorisnih minerala. Samim tim, veoma je važno osigurati uspešan rad flotacijskog postrojenja kroz dostizanje zadovoljavajućih tehno-ekonomskih pokazatelja. Cilj upravljanja procesom flotacijske koncentracije je upravo optimizacija kvaliteta i iskorišćenja korisne komponente u koncentratu uz maksimizaciju profita. Shodno tome, istraživanja na polju modelovanja i upravljanja ovim procesom zauzimaju značajno mesto u praksi kontolnog inženjenringa.Teorijska istraživanja u okviru doktorske disertacije obuhvatila su analizu položaja ...
    flotacijska koncentracija, modelovanje, upravljanje, inteligentni sistem, soft kompjuting, fazi logika, veštačke neuronske mreže
    ... (tabela 4). Zaključeno je da dati kontrolni sistem pokazuje slične performanse, bilo da su u pitanju kompleksne baze fazi pravila ili jednostavna baza sa svega 11 pravila [Carvalho and Durão (2000)]. Ipak, minimizacija baze fazi pravila je kompleksan postupak i trebalo bi da obuhvati obimnija istraživanja ...
    ... RUDARSKO-GEOLOŠKI FAKULTET 78 S ad rž aj C u (% ) Is ko riš će nj e C u (d e l. j e d .) Dan 1 Dan 5 Dan 10 Dan 15 Dan 20 Dan 25 Dan 30 Dan 1 Dan 5 Dan 10 Dan 15 Dan 20 Dan 25 Dan 30 dnevna noćna jutarnja dnevna noćna jutarnja Slika 39. Iskorišćenje i kvalitet koncentrata ...
    ... saradnici tvrde da višeslojni perceptroni, uprkos popularnosti, nemaju veliku primenu u ekstrakciji svojstava iz slika flotacijske pene, navodeći da je jedan od razloga taj što su neuronske mreže sa velikim brojem skrivenih slojeva komplikovane za trening, te stoga ne mogu dati dosledne ili robusne ...

  • An Integrated Environment for Management and Exploitation of Linguistic Resources

    Ranka Stanković, Ivan Obradović (2009)
    ... marked as n82. C. Spatial data search The linguistic resources and tools presented were also implemented for improvement of spatial data search in Ge- olISS (Geological information system of Serbia) [13]. The system was development by the Faculty of Mining and Ge- ology and funded by ...
    ... within various institutions aimed at gathering the necessary geological data. GeolISS is now a standard tool for han- dling spatial data in all projects funded by the Ministry. Bearing in mind the vast amount of textual data in Ge- olISS (observations, interpretations, field work day books, ...
    ... internal affairs). The upper part of the form is used for data pertaining to the compound as a whole: the code used for compound inflection, syntactic and semantic categories, comments, etc. The lower part of the form con- tains data related to simple word forms that are parts of the compound ...

  • Machine learning based landslide assessment of the Belgrade metropolitan area: Pixel resolution effects and a cross-scaling concept

    Uroš Đurić, Miloš Marjanović, Zoran Radić, Biljana Abolmasov (2019)
    Improvements of Machine Learning-based landslide prediction models can be made by optimizing scale, customizing training samples to provide sets with the best examples, feature selection, etc. Herein, a novel approach, named Cross-Scaling, is proposed that includes the mixing of training and testing set resolutions. Hypothetically, training on a coarser resolution dataset and testing the model on a finer resolution should help the algorithm to better generalize ambiguous examples of landslide classes and yield fewer over/underestimations in the model. This ...
    klizišta, podložnost, mašinsko učenje

  • 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
    ... (2002) On evaluating performance of classifiers for rare classes. IEEE Int Conf on Data Mining, Maebashi City, Japan 641:644 Kanevski M, Pozdnukhov A, Timonin V (2009) Machine Learning for Spatial Environmental Data: Theory. CRC Press, Boca Raton, USA, Applications and Software Karajovanovik M ...
    ... of scientific research work in 2023": grant no. 451-03-47/2023-01/200126 (Faculty of Mining and Geology) and grant no. 451–03-68/2020—14/200092 (University of Belgrade, Faculty of Civil Engineering). Data availability The datasets generated during and/or analyzed dur- ing the current study are ...
    ... G (1989) The Chemistry of Soils. Oxford University Press Steinbach M, Tan PN (2009) kNN: k- Nearest Neighbors. In: The top ten algorithms in data mining, Ist edn. Chapman and Hall/CRC Waske B, Braun M (2009) Classifier ensembles for land cover mapping: using multitemporal SAR imagery. ISPRS J ...

  • Еоценска фауна југозападног дела Сирт басена (Либија)

    Љупко Рундић, Мери Ганић (2020)
    Еоцен, крупни мекушци, нумулити, ЈЗ Сирт басен, Либија

  • The Importance of Geotechnical Investigations for the Construction of Transfer Station „Prelići“ on Landfill in Cacak – Serbia

    Dragoslav Rakić, Irena Basarić, Jovana Janković, Tina Đurić (2019)
    For the purpose of the facilities construction within the transfer station „Prelici“ in Cacak, specific geotechnical investigations were carried out based on which the technological project with the facilities schedule was developed. Significant deviations in relation to the presented results were determined during earthworks, so the additional geotechnical investigation works were carried out. Since the new investigation works have determined a different cross section of the terrain, it was proposed to move the planned facilities which led to the ...
    landfill, geotechnical investigations, transfer station
    ... urban industrial environment. In addition, an analysis of the available waste composition data and their comparison with the total mass of waste with data from different parts of the world and the average data for Serbia. 4. ANALYSIS OF GEOTECHNICAL CONDITIONS FOR THE CONSTRUCTION OF THE TRANSFER ...
    ... All rights reserved / www.cisapublisher.com (Figure 2). However, during preparatory earthworks, significant deviations were identified, as the data on the terrain were in contradiction with the presented results in the geotechnical documentation. Therefore, at the beginning of 2014, additional ...
    ... 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 ...

  • Business Models for Small-scale Biomass Projects Development

    Dejan Ivezić, Miodrag Gluščević, Marija Živković (2019)
    Biomass is recognized as the most promising renewable energy source in Serbia. The share of biomass in Serbian final energy consumption is over 10%, but mostly related to traditional use in stoves and ovens. One of the main obstacles for wider implementation of contemporary biomass facilities is the inexperience of consumers and stakeholders in the implementation of “innovative” business models, especially in the cases of small-scale projects. In this paper, three different business models (public utility company, energy cooperative ...
    ... Business Models for Small-scale Biomass Projects Development Dejan Ivezić1, Miodrag Gluščević2, Marija Živković1 1University of Belgrade – Faculty of Mining and Geology 2Standing Conference of Towns and Municipalities, Belgrade Abstract: Biomass is recognized as the most promising renewable energy source ...
    ... received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691661. References [1] Ministry of Mining and Energy, Energy Sector Development Strategy of the Republic of Serbia for the period by 2025 with projections by 2030, Official Gazette of the Republic ...

  • Numerical modeling of Selanac debris flow propagation using SPH code

    Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi (2021)
    The Selanac debris flow is a very huge event triggered after extreme rainfall caused by Cyclone Tamara activity in the Republic of Serbia in May 2014. The Selanac case study was already modelling in different programs using Voellmy rheology assumptions like RAMMS software. In this paper research are focusing particularly on the process of debris flowing from initiation zone to main deposition area using Geoflow SPH two-phase model considering frictional rheology law. Main rheological parameters are back-calculated using also ...
    debris flow, modelling, SPH code, DEM
    ... 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 ...
    ... modeling of Selanac debris flow propagation using SPH code Jelka Krušić, Biljana Abolmasov & Miloš Marjanović University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia Manuel Pastor & Saeid M. Tayyebi UPM, ETS Ingenieros de Caminos, Department of Applied Mathematics, Madrid ...

  • Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis

    Ivan Kojić, Achim Bechtel, Reinhard Sachsenhofer, Dragana Životić, Ksenija Stojanović (2019)
    ... pyrolysis durnng 4 hours at the temperatures ог 400 "С (Pyr400). 450 *C (Pyr450) and 500 *C (Pyr500). This temperature range was chosen according (0 data from thermogravimetric analysis which inđicate that the first significant mass 1055 (after releasing ог moisture) occurs between 400 "С and 500 %C ...
    ... 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 ...

  • The correlation of Upper Miocene lithostratigraphic units of the southern part of the Pannonian basin

    Filip Anđelković, Dejan Radivojević (2019)
    gornji miocen, litostratigrafske jedinice, formacije, Panonski basen
    ... Riftogeneza se odvijala po modelu asimetričnog jednostavnog smicanja. Analiza sinkinematskih seizmičkih refleksija pokazuje da je normalno rasedanje migriralo vremenski i prostorno i da se odvijalo u toku velikog vremenskog intervala (otprilike 20 – 5.5 Ma). Sistem panonskog basena obuhvata veći broj ...
    ... on the level of formations and members and are characterized by their lithological concent, depositional environments, using field and borehole data, and geophysical methods (reflection seismics and geophysical well-logging). Such correlation has great significance for the knowledge of the Pannonian ...
    ... Congress, Vrnjačka Banja, pp 55-59 6. Magyar, I., Fogarasi, A., Vakarcs, G., Bukó, L. & Tari, G., (2006). The largest hydrocarbon field discovered to date in Hungary: Algyő. In Golonka, J., & Picha, F.J., (Eds) : The II KONGRES GEOLOGA BOSNE I HERCEGOVINE SA MEĐUNARODNIM UČEŠĆEM II КОНГРЕС ГЕОЛОГА ...

  • Mikroplastika u peloidima iz Srbije i Slovenije

    A. Šajnović, G. Gajica, F. Prosenc, S. Stojadinović, G. Veselinović, P. Trebše, P. Dabić, B. Jovančićević (2023)
    ... 2023 kontaminaciju mikroplastikom (Tabela 1). lako je malo verovatno da će mikropalstika dimenzija između 1 i 5 mm preći barijeru ı pokazati bilo kakav fizički i toksični efekat na ljude, njihovo prisustvo ukazuje na to da je kontaminacija manjim mikro- i nanočesticama verovatna i moguća u ovim ...
    ... potrebna kako bi se pouzdanije interpretirali podaci i objasnilo ponašanje čestica mikroplastike u peloidima, budući da oni imaju široku i različitu primenu kod ljudi. Literatura 1. da Costa,J., Santos, P., Duarte, A., Rocha-Santos, T. Sci. Tota! Environ. 566-567 (2016) 15-26. 2. Alimi, O., Budarz ...
    ... Iz tog razloga za ispitivanja mikroplastike u okviru ovog rada izabrani su peloidi sa teritorije Republike Srbije ı Slovenije. Dodatni razlog je da su obe zemlje bogate banjama sa dugom tradicijom u balneoterapiji, gde se peloidi koriste u terapeutske i estetske svrhe. U Republici Srbiji banje ...

  • Aлтерације перидотита контролисане карактером флуида на примеру харцбургита Рудника - Серпентинизација или талкизација?

    Стефан Петровић, Наталија Батоћанин (2020)
    У раду су приказани резултати испитивања серпентинисаних харцбургита Брђана (43°58'45.1" СГШ, 20°25'12.6" ИГД) и талкизираних харцбургита откривених у интервалу 429-559.8 m у истражној бушотини 330А/18 (44°07'33.2" СГШ, 20°30'28.5" ИГД) на Руднику. Узорци оба локалитета показују карактеристике резидуалних харцбургита из омотача, односно тектонита; лепидобластичне, бластозрнасте, или порфирокластичне структуре и масивне текстуре. Серпентинисани харцбургити и серпентинити Брђана су изграђени од серпентина, ретких реликата оливина и ортопироксена, акцесорног спинела, и веома ретког секундарног магнезита и магнетита. Најдоминантнији састојак (местимично гради и преко ...
    Рудник, Брђани, харцбургити, серпентинити, талк
    ... јски серпентин, средњег састава [(Mg10,66Fe2+ 1,04)11,70(Fe3+ 0,06Al0,03Si7,94)8,03O5(OH)4]. Присуство реликата оливина и ортопироксена указује да се серпентинизација одвијала на нижим температурама (<400°C) деловањем водених раствора. Низак садржај алуминијума (0,00-0,03 a.p.f.u.) потврђује овакво ...
    ... минерала: форстерит + талк, била изнад 490°С. Повишен садржај алуминијума (>3 a.p.f.u.) у серпентину потврђује ово гледиште. Остаје отворено питање да ли су талкизирани перидотити индикатори близине киселих магматских стена? Серпентинисани перидотити то свакако нису. ...
    ... детектор у 1D стандардном моду са CuKα1,2 извором зрачења (U = 40 kV и I = 30 mA). Узорак је припремљен у носачу узорка од монокристала силицијума да би се снизио шум. Рендгенски дифрактограм је прикупљен у угаоном опсегу 5-75° 2θ, са кораком 0,01°, и брзином прикупљања података од 5 °/min. Кристалне ...

  • Mineralogical analysis of a clay body from Zlakusa, Serbia, used in the manufacture of traditional pottery

    Maja Milošević, Biljana Đorđević, Mihovil Logar (2020)
    калцит, сирова глина, традиционална керамика, Злакуса
    ... years ago, of the special properties that clay acquires upon firing, the first synthetic material was created: ceramic (Vandiver et al., 1989). To date, in Serbia, only the Zlakusa area continues to produce pottery in the old, archaic manner (Djordjević-Bogdanović, 1996, 2016; Djordjević, 2005, 2013; ...
    ... application; and the final clay body (ClIBd) after mixing the CIMx with the CC in the desired ratio. Methods The X-ray powder diffraction (XRPD) data were collected on a Rigaku SmartLab X-ray powder diffractometer using Bragg- Brentano geometry and Cu-Ko. radiation in the scan range of 3-70%0 ...
    ... 550%C for 1 h (H). The mineral phases were identified using the Rigaku PDXL software and the PDF-2 database (International Centre for Diffraction Data). The chemical com- position was determined by X-ray fluorescence (XRF) spectros- copy using a PANalytical MiniPal 4 XREF spectrometer equipped ...

  • Mesozoic carbonate rocks in Serbia used as dimension stone

    Vesna Matović, Tijana Vojnović Ćalić (2016)
    The building industry in Serbia uses, to a great extent, imported natural stone for architectural purposes. The significance of local deposits, particularly limestones, is not adequately perceived despite the country’s abundance of these valuable resources. Therefore, this study focuses on Serbia’s Mesozoic carbonate rocks, specifically on the deposits of four selected quarries: Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, ...
    Ukrasni kamen, Mezozoik, Krečnjak, Srbija, Petrografija, Fizičko-mehanička svojstva
    ... hanical prop- erties were compared to the technical requirements of a suitable national standard (SRPS B.B3.200 1994). Results Petrographic data of carbonate rocks Petrological properties of the Klisura limestone In geological practice, the Klisura limestone is known as “Bulog limestone” ...
    ... low porosity, of very low water absorption, hard, and of high to moderately high values of compressive strength. The sta- tistically analysed data confirmed that the representative values of the technical properties satisfy the requirements of the withdrawn SRPS B.B3.200 (1994) used for reference ...
    ... 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 ...

  • A Description of Morphological Features of Serbian: a Revision using Feature System Declaration

    Cvetana Krstev, Ranka Stanković, Vitas Duško (2010)
    In this paper we discuss some well-known morphological descriptions used in various projects and applications (most notably MULTEXT-East and Unitex) and illustrate the encountered problems on Serbian. We have spotted four groups of problems: the lack of a value for an existing category, the lack of a category, the interdependence of values and categories lacking some description, and the lack of a support for some types of categories. At the same time, various descriptions often describe exactly the same ...
    Morphology, Lexicon, lexical database, Standards for LRs
    ... System Declaration, ISO/TC 37/SC 4. ISO. (2009) ISO 12620 Terminology and other language and content resources – Data Categories – Specification of data categories and management of a data category registry for language resources Kešelj, V., Kešelj, T., and Zlatić, L. (2004). R{j}ecnik.com: Engl ...
    ... one PoS as a supertype in order to avoid redundancy. These descriptions are connected with the appropriate morpho-syntactic categories given in the Data Category Registry (ISO, 2009). For example, the declaration for the grammatical gender is:
    ... 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 ...

  • 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

  • Vodosnabdevanje i održivo upravljanje podzemnim vodnim resursima u Srbiji

    Dušan Polomčić, Zoran Stevanović, Dragoljub Bajić, Bojan Hajdin, Vesna Ristić-Vakanjac, Petar Dokmanović, Saša Milanović (2012)
    Slično većini evropskih zemalja, udeo podzemnih voda u javnom vodosnabdevanju u Srbiji je oko 75%. Najveće rezerve su akumulirane u vodonosnim naslagama intergranularne poroznosti neogene i kvartarne starosti, kao i u karstnim izdanima. One su jedini izvor vodosnabdevanja pijacom vodom za Vojvodinu i veći deo Srbije. Delovi sa malim rezervama podzemnih voda su Šumadija i južni delovi zemlje, gde se koriste u većoj meri površinske vode. Do sada izvedena hidrogeološka istraživanja pokazuju da se zahvata oko 30% obnovljivih rezervi ...
    ... vodosnabdevanja je klju an ako se ima u vidu da podzemne vode u estvuju sa oko 75% od ukupnih koli ina voda koje se koriste za javno snabdevanje stanovništva u Srbiji. U nekim oblastima republike, trenutni kapaciteti izvorišta podzemnih voda nisu dovoljni da podmire potrebe stanovništva. Me utim, postoje ...
    ... vodosnabdevanja je kljucan ako se ima u vidu da podzemne vode u¢estvuju sa oko 75% od ukupnih koli¢ina voda koje se koriste za javno snabdevanje stanovniStva u Srbiji. U nekim oblastima republike, trenutni kapaciteti izvoriSta podzemnih voda_nisu dovoljni da podmire potrebe stanovniStva. Medutim, postoje ...
    ... podzemnih voda su Šumadija i južni delovi zemlje, gde se koriste u ve oj meri površinske vode. Do sada izvedena hidrogeološka istraživanja pokazuju da se zahvata oko 30% obnovljivih rezervi pozemnih voda (67 m3/s), bez u estvovanja podzemnih voda dobijenih primenom vešta kog prihranjivanja ili r ...