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Упит dcterms_subject_txt:porosityGeneral Computer Science

747 items

  • Rezultati ispitivanja parametara čvrstoće i dinamičkih svojstava mermera i mogućnost njihove korelacije

    Jelena Majstorović-Necković, Vladimir Čebašek, Veljko Rupar (2023)
    Ispitivanja stena kao radne sredine, odnosno materijala sa kojim se gradi, na kome se gradi i u kome se gradi, svojom složenošću zahteva njeno svestrano izučavanje po velikom broju parametara. Zadatak Mehanike stena je da što bolje upozna ponašanje stenske mase i njenu otpornost na dejstvo pritiska, zatezanja i smicanja, kao i dinamičkih svojstava. Poznavanje navedenih parametara i njihova korelacija omogućavaju pouzdaniji izbor parametara za projektovanje danas sve zahtevnijih uslova kako podzemne, tako i površinske eksploatacije. U ovom radu ...
    mermer, jednoosna čvrstoća na pritisak, čvrstoća na istezanje, brzina longitudinalnih elastičnih talasa, korelacija

  • Hronološki pregled razvoja površinske eksploatacije lignita u Srbiji

    Bojan Dimitrijević, Radmila Gaćina, Bogoljub Vučković (2023)
    U ovom preglednom radu dat je istorijski pregled razvoja površinske eksploatacije lignita na teritoriji Srbije, uz kratak osvrt na geološki nastanak i kvalitet i rezerve uglja, kao i mogućnosti korišćenja za dalju upotrebu. Kolubarski, Kostolački i Kovinski ugljeni baseni lignita u Srbiji, ne računajući Kosovsko-Metohijski i Drenički u sastavu AP Kosovo i Metohija po Rezoluciji 1244 UN, su ležišta najrasprostranjenijeg uglja - lignita u Srbiji koji se eksploatiše od druge polovine 20. veka na velikom broju površinskih kopova ...
    površinska eksploatacija ugalja, lignit, Kolubara, Kostolac, Srbija

  • Proširivanje upita zasnovano na leksičkim resursima

    Ranka Stanković, Ivan Obradović, Cvetana Krstev (2009)
    U radu je opisano kako se leksički resursi za srpski jezik i softverski alati, razvijeni u okviru Grupe za jezičke tehnologije Univerziteta u Beogradu, mogu koristiti za unapređenje postavljanja upita. Rezultati pretrage mogu biti značajno unapređeni korišćenjem različitih leksičkih resursa, kakvi su morfološki rečnici i semantičke mreže. Izloženi pristup može se iskoristiti i u Sistemu naučnih, tehnoloških i poslovnih informacija, jer je efikasno pretraživanje ovog dragocenog resursa, imajući u vidu njegovu heterogenost i obim, kao i preovladavajući tekstualni sadržaj, ...
    ... povezuju sa drugim sinsetima. Prva mreža reči za engleski jezik pod nazivom Prinstonski wordnet (PWN) razvijena je 1985. godine u Cognitive Science Laboratory Prinstonskog univerziteta (Fellbaum, 1998). EuroWordNet (EWN) je bio projekat u okviru koga su pored mreže reči za engleski razvijene ...
    ... Piperidis, V. Karakaletsis (eds.), pp. 97-104. [2] Tufiş, D. (ed.). (2004) Special Issue on BalkaNet Project, Romanian Journal on Information Science and Technology, Bucureşti, Publishing house of the Romanian academy. [3] Vitas D., Krstev C. (2007), „Extending Serbian E dictionary by the ...

  • Analiza uporednog praćenja temperature površine ohlađenih materijala pri njihovom zagrevanju do ambijentalne temperature

    Stevan Đenadić, Ljubiša Tomić, Vesna Damnjanović, Katarina Nestorović (2021)
    U datom eksperimentalnom radu su termografskim metodama ispitivane termofizičke karakteristike različitih materijala. Za ispitivanja su izabrani mesingani niovčić, ugalj i pelet, jer imaju različita termoizolaciona svojstava i različito stanje površine. Uzorci su najpre hlađeni, a zatim je njihovo zagrevanje na sobnoj temperaturi praćeno termalnom kamerom. U drugom delu eksperimenta, korišćena je impulsna termografija, a zagrevanje površine uzoraka vršeno je svetlosnom pobudom.
    termografija, impulsna termografija, nedestruktivno testiranje materijala, mesing, ugalj, pelet

  • Numerical modelling of the roughly simultaneous emplacement of two distinct ophiolite belts

    Nikola Stanković, Vesna Cvetkov, Vladica Cvetković (2024)

  • Просторни положај лежишта угља Ђурђевик: геофизичко-геолошки модел

    Синиша Арсеновић (2019)
    Лежиште угља Ђурђевик представља источни део Бановићког угљеног басена и припада северној страни босанске офиолитске зоне унутрашњих Динарида у чији састав улазе стене палеозојске, мезозојске и кенозојске старости. Језерска доњомиоценска угљоносна серија изграђена је од лапоровито-глиновитих седимената са једним слојем мрког угља. Дебљина угљеног слоја креће се у интервалу од 5 до 25 m са генералним правцем пружања СЗ - ЈИ и падом према ЈЗ. У зони обухваћеноj геофизичким истраживањима изражена je пострудна тектоника у виду раседа мањег и ...
    рефлективна сеизмика, 3Д геофизичко-геолошки модел, угаљ, синтетички модел, моделирање
    ... of the coal and the reflective seismic was chosen as the most suitable method for this research. The synthetic model of the area on which the computer simulations of the wave response were carried out was based on the forecast geological profile and the data of the exploration and exploitation ...
    ... survey. ASEG Extended Abstracts 2004: 17th Geophysical Conference, pp.1-4 Zhou, B., Haterly, P., 2000. Pushing coal seismic to its limits through computer aided interpretation and 3D seismic. Exploration Geophysics 31(2), 343-346. Zhou, B., Hatherly, P., 2005. Delineation of geological structures ...
    ... област: Геофизика; _______________________________________________ др Милован Урошевић, ванредни професор, Curtin University, Faculty of Science and Engineering; ужа научна област: Геофизика; Датум одбране: ______________________ ЗАХВАЛНОСТ ...

  • Electronic Dictionaries - from File System to lemon Based Lexical Database

    Ranka Stanković, Cvetana Krstev, Biljana Lazić, Mihailo Škorić (2018)
    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 ...
    ... the 11th International Conference on Language Resources and Evaluation - W23 6th Workshop on Linked Data in Linguistics : Towards Linguistic Data Science (LDL-2018), LREC 2018, Miyazaki, Japan, May 7-12, 2018 | 2018 | | http://dr.rgf.bg.ac.rs/s/repo/item/0002011 Дигитални репозиторијум Рударско-геолошког ...
    ... will prove useful for other languages as well. 8. Acknowledgements This research was partially supported by Serbian Ministry of Education and Science under the grants #III 47003 and 178003. 9. Bibliographical References Attia, M., Tounsi, L., and Van Genabith, J. (2010). Au- tomatic Lexical Resource ...
    ... Cimiano, P., Buitelaar, P., McCrae, J., and Sintek, M. (2011). LexInfo: A declarative model for the lexicon- ontology interface. Web Semantics: Science, Services and Agents on the World Wide Web, 9(1):29–51. Courtois, B. and Silberztein, M. (1990). Dictionnaires électroniques du français, volume ...

  • Structural dissymmetrization of optically anisotropic Grs64±1Adr36±1Sps2 grandite from Meka Presedla (Kopaonik Mt., Serbia)

    Pavle Tančić, Aleksandar Kremenović, Predrag Vulić (2019)
    In this paper, grandite core with Grs64±1Adr36±1Sps2composition was crystallographically studied. This core represents zone A of the macroscopically visiblefive A–E zones of the optically anisotropic Grs58–64 Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all ...
    grandite, XRPD, crystal structure, structural dissymmetrization

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... J. Microsc. 2006, 221, 89-109. [CrossRef] [PubMed] 21. Williams, D.B.; Carter, C.B. Transmission Electron Microscopy: A Textbook for Materials Science; Winter: New York, NY, USA, 2009; ISBN 9780387765006. 22. Goldschmidt, V.M. Atlas Der Krystallformen: Plates and Text; Winter: Heidelberg, Germany ...

  • 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 (2020)
    Geochemistry and Petrology

  • 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
    ... the stroke converter. Data on the stroke and load of the smooth rod for one complete pump cycle (upstroke and downstroke) are transferred to a computer, where a developed model is used to process the data based on pre-set parameters such as rod string, pumping speed, and damping factor. The result ...
    ... reliable tool for identifying the condition of the pumping system and assessing the characteristics of the fluid in the wellbore. The primary goal of computer-controlled oil extraction using deep well pumping is precisely to obtain an accurate downhole dynamogram. 16 4. MACHINE LEARNING Machine ...
    ... performance on given tasks through experience, without the need for explicit programming. In this context, experience refers to the data that the computer interacts with during the learning process. To understand why to use machine learning, compare it with the traditional approach to programming ...

  • Ontološki model upravljanja rizikom u rudarstvu

    Olivera Kitanović (2021)
    Rudarska proizvodnja obuhvata kompleksne tehnološke sisteme, što nameće potrebu za uspostavljanjem i unapređivanjem sistema upravljanja rizikom. Heterogenost i obim podataka neophodnih za upravljanje rizikom zahtevaju sistem koji ih na fleksibilan način integriše i omogućava njihovo optimalno korišćenje. Osnovni cilj ove disertacije je razvoj ontologije za domen rudarstva i na njoj zasnovanog modela za upravljanje rizikom. Njegova realizacija podrazumeva i implementaciju algoritama ekstrakcije informacija za popunjavanje ontologije, kao i odgovarajuće softversko rešenje. Razvoj modela obuhvata i značajno proširenje rudarskog korpusa, kao ...
    rudarstvo, rizik, upravljanje rizikom, procena rizika, ontologija, semantička mreža, ekstrakcija informacija, upravljanje znanjem, računarska lingvistika
    ... on of Natural Language.” In LITP Spring School on Theoretical Computer Science, 34–50. Springer. Gruber, Thomas R. 1995. “Toward Principles for the Design of Ontologies Used for Knowledge Sharing?” International Journal of Human-Computer Studies 43 (5–6): 907–28. Hearst, Marti A. 1992. “Automatic Acquisition ...
    ... network, information extraction, knowledge management, computational linguistic Scientific field: Mining Engineering Scientific subfield: Computer science and systems engineering UDC Number: UDC Number: 004:004.42/.82:519.8 005.1/.7:005.334:622 519.237/.245:519.76:622 614.8:622:681 ...
    ... Badri, Adel, André Gbodossou, and Sylvie Nadeau. 2012. “Occupational Health and Safety Risks: Towards the Integration into Project Management.” Safety Science 50 (2): 190–98. Beasley, Mark S, Richard Clune, and Dana R Hermanson. 2005. “Enterprise Risk Management: An Empirical Analysis of Factors Associated ...

  • 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)
    ... of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia 2 Department of Physics, Faculty of Science, University of Zagreb, Bijenička c. 32, HR-10000 Zagreb, Croatia JUniversity of Belgrade, Faculty of Pharmacy, Department of Bromatology, Belgrade ...

  • Numerical modelling of a single intra-oceanic subduction for the origin of the Balkan ophiolites

    Nikola Stanković, Vesna Cvetkov, Vladica Cvetković (2024)

  • Multihazard Exposure Assessment on the Valjevo City Road Network

    Miloš Marjanović, Biljana Abolmasov, Svetozar Milenković, Uroš Đurić, Jelka Krušić, Mileva Samardžić Petrović (2019)
    Prirodni hazardi, izloženost, klizišta, poplave, bujice, GIS, R

  • Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation

    Maja Franković, Nevenka Novaković, Vesna Matović (2015)
    The Dark Gate is the monument of culture, part of the cultural and historical complex of the Belgrade Fortress. It is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms. During 2007, detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping. A correlation scheme ‘‘intensity– damage category’’ was made according to the type, intensity, and distribution of ...
    Krečnjak, mapiranje, Indeks raspadanja, brzina raspadanja, progresija
    ... 6193 Massa S, Naldini S, Rorro A (1991) A system of classification of the decay of stone monuments. In: Baer NS, Sabbioni C, Sors A (eds) Science, technology and european cultural heritage. Butterworth-Heinemann, Oxford, pp 859-862 McCabe S, Smith B J, Warke P A (2007) An holistic approach ...
    ... geological history of the Belgrade fortress. In: Čubrilović V (ed) Belgrade fortress in past, present and future, vol.XXXVI (9), Serbian academy of science and art, p 91-102 Popović M (2006) The fortress of Belgrade, 2nd edn, Javno preduzece “Beogradska tvrdjava”, Belgrade (in Serbian) Rothert E ...

  • Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)

    Filip Abramović, Miroslav Popović, Vladimir Simić, Vesna Matović, Radmila Šerović (2024)
    General Materials Science

  • 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 ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... production, and excessive gas production through the pump, the API method does not provide accurate results. API is the result of electrical analog computer studies of sucker rod motion. This predated the numerical solution of the wave equation and was not as general. However, the analog study did ...
    ... OILFIELD SERVICES, Modern Design and Simulation of Rod Pumping Systems for Deviated or Vertical Wells 49 [14] API. API Bul 11L2 Catalog of Analog Computer Dynamometer Cards, 1st ed.; American Petroleum Institute: Dallas, TX, USA, 1969. [15] Bommer, Paul M., Podio A. L., 2015. 7he Beam Lift Handbook ...

  • Могућности и значај коришћења појава природног лековитог фактора на територији Србије у дермокозметици

    Сава Вуковић (2024)
    Сведоци смо да је данас потражња усмерена ка ефикасним производима које нуди дермокозметика јер употреба дермокозметичких производа носи много мање ризике и има далеко мањи токсични потенцијал у односу на дерматолошке лекове. Важно место у дермокозметици заузимају појаве природног лековитог фактора - термалне воде и лековита блата. Термалне / термоминералне воде садрже макро-, микро- и фармаколошко-терапеутске елементе, тј. eлементе у траговима који су доказали своју ефикасност у нези и заштити коже и у побољшању одређених кожних поремећаја. То се ...
    природни лековити фактор, термоминералне воде, лековито блато, дермокозметика, Луковска бања, Бања Риђица
    ... Hinz R.5., Lorenze C.R(1999). Metals and the skin; - BarelA.O., Paye M., Maihach H. (2001), Handbook of Cosmetic Science and Technology; - MitsuiT.(1997). New Cosmetic Science; - _ Čajkovac M. (2004), Koseronornja; - Bynera T., BacwubepMh IL (2001). BuraMMHM y KO3MEČTHUKHM TIpOH3BO/UHMa; ...
    ... 75-84. 7. MajkoBam M. (2004), Koseromoruja . Dreno atal.(2014). The science of dermocosmetics and its role in dermatology. J Eur. Dermatol. Venerol. 9. Des Marai D.J.(2000). Whhen did photosyntesis emerge on Earth. Science 8, Vol. 289. no. 5485, pp. 1703 – 1705 10. Estrada J.P., et al, (2001): ...
    ... (medicinal muds). Applied Clay Science 50, 47-50. 14. Gomes C., Carretero M.L, Pozo M., Maraver F., Cantista P., Armijo F., Legido J.L., Teixeira F., Rautureau M., Delgado R. Peloids and pelotherapy: Historical evolution, classification and glossary, Clay Science, May 2013 DO!I: 10.1016/j.clay ...

  • Substitution reactions of some novel sterically hindered monofunctional Pd(II) complexes

    Aleksandar Mijatović, Jovana Bogojeski, Biljana Petrović, Živadin D. Bugarčić (2011)
    Reakcije supstitucije monofunkcionalnih kompleksa [(TLtBu)PdCl]+ i [Pd(tpdm)Cl]+, gde je TLtBu = 2,6-bis[(1,3-di-terc-butilimidazolin-2-imino)metil]piridin i tpdm = terpiridindimetan, sa nukleofilima kao što su: tiourea, I−, Br−, NO2−, piridin i dimetil-sulfoksid (DMSO) proučavani su u 0,1 M vodenom rastvoru NaClO4 u prisustvu 10 mM NaCl. Reakcije su sprovedene na tri različite temperature (288, 298 i 308 K) korišćenjem tehnike zaustavljenog protoka na različitim temperaturama. Reakcije supstitucije su praćene pod uslovima pseudo prvog reda sa velikim viškom nukleofila. Dobijeni rezultati pokazuju da kompleks ...
    Materials Chemistry, Inorganic Chemistry, Physical and Theoretical Chemistry
    ... onal Pd(II) complexes Aleksandar Mijatović, Jovana Bogojeski, Biljana Petrović, Živadin D. Bugarčić ⇑ University of Kragujevac, Faculty of Science, R. Domanovića 12, 34000 Kragujevac, Serbia a r t i c l e i n f o Article history: Received 29 July 2011 Received in revised form 28 October 2011 ...
    ... monofunctional Pd(II) complexes Aleksandar Mijatovi¢, Jovana Bogojeski, Biljana Petrovic, Zivadin D. Bugarti¢ * University of Kragujevac, Faculty of Science, R. Domanovica 12, 34000 Kragujevac, Serbia ARTICLE INFO ABSTRACT Article history: Received 29 July 2011 Received in revised form 28 October 2011 ...
    ... asso- ciative supported by the negative values of DS–. Acknowledgements The authors gratefully acknowledge financial support from the Ministry of Science and Technological Development of the Republic of Serbia, Project No. 172011. Appendix A. Supplementary material Supplementary data associated with ...