Претрага
266 items
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A necessary and sufficient condition for an algebraic integer to be a Salem number
Dragan Stankov (2019)We present a necessary and sufficient condition for a root greater than unity of a monic reciprocal polynomial of an even degree at least four, with integer coefficients, to be a Salem number. This condition requires that the minimal polynomial of some power of the algebraic integer has a linear coefficient that is relatively large. We also determine the probability that an arbitrary power of a Salem number, of certain small degrees, satisfies this condition.Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomials... Mossinghoff, “List of small Salem numbers”, http://www.cecm.sfu.ca/~mjm/Lehmer/ lists/SalemList.html. [7] C. Smyth, “Seventy years of Salem numbers: a survey”, Bull. Lond. Math. Soc. 47 (2015), no. 3, p. 379-395. [8] D. Stankov, “On the distribution modulo 1 of the sum of powers of a Salem number”, C. ...Dragan Stankov. "A necessary and sufficient condition for an algebraic integer to be a Salem number" in Journal de theorie des nombres de Bordeaux (2019). https://doi.org/10.5802/jtnb.1076
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Održivo korišćenje mađarsko-srpskih međugraničnih vodnih tela
Dušan Polomčić, Zoran Stevanović, Saša Milanović, Stanko Sorajić, Bojan Hajdin, Željko Kljajić (2010)Dušan Polomčić, Zoran Stevanović, Saša Milanović, Stanko Sorajić, Bojan Hajdin, Željko Kljajić. "Održivo korišćenje mađarsko-srpskih međugraničnih vodnih tela" in Vodoprivreda 42 no. 04-Jun, Beograd : Jugoslovensko društvo za odvodnjavanje i navodnjavanje (2010): 223-235
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Improving Document Retrieval in Large Domain Specific Textual Databases Using Lexical Resources
Large collections of textual documents represent an example of big data that requires the solution of three basic problems: the representation of documents, the representation of information needs and the matching of the two representations. This paper outlines the introduction of document indexing as a possible solution to document representation. Documents within a large textual database developed for geological projects in the Republic of Serbia for many years were indexed using methods developed within digital humanities: bag-of-words and named ...Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović. "Improving Document Retrieval in Large Domain Specific Textual Databases Using Lexical Resources" in Trans. Computational Collective Intelligence - Lecture Notes in Computer Science 26, Springer (2017). https://doi.org/10.1007/978-3-319-59268-8_8
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Demise of the Wetterstein Carbonate Platform and onset of the Dachstein Carbonate Platform recorded in deep-water successions of the East Bosnian-Durmitor megaunit (Pliješevina, northern Montenegro, Dinarides)
Milica Mrdak, Eva Wagerer, Milan Sudar, Nevenka Djerić, Martin Đaković, Hans-Jürgen Gawlick. "Demise of the Wetterstein Carbonate Platform and onset of the Dachstein Carbonate Platform recorded in deep-water successions of the East Bosnian-Durmitor megaunit (Pliješevina, northern Montenegro, Dinarides)" in Geologica Carpathica, Central Library of the Slovak Academy of Sciences (2024). https://doi.org/10.31577/GeolCarp.2023.26
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Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine
Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović (2019)Availability is one of the most used terms in maintainability engineering. This concept is used to denote: The quality of service of an engineering system, i.e., machines, weak points’ analysis, asset management, as well as making decisions in the process of life cycle management. Availability is an overall indicator and contains partial indicators that are oriented towards reliability, maintenance, and logistical support. Availability presents a variable value and changes in time and space. Usually, availability is shown as the ...Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović. "Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine" in Energies, MDPI AG (2019). https://doi.org/10.3390/en12214044
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Prioritization of strategic measures for strengthening the security of supply of the Serbian natural gas sector
To strengthen the security of supply of the Serbian gas sector, it is necessary to analyze the impact of planned strategic measures. The analysis involves the identification of the most influential threats to the security of natural gas supply and prioritization of the strategic measures for overcoming the consequences of threats. The proposed methodology is based on Fuzzy Analytic Hierarchy Process. The obtained weights for the identified threats and strategic measures are formed according to experts' judgments. The results ...Sigurnost snabdevanja, Donošenje odluka, Snabdevanje prirodnim gasom, Fazi AHP, Energetski indikatori... as well as the national regulatory authority (1) and professional associations (2). The main criteria for choosing the appropriate experts for the survey were the professional involvement in the natural gas sector planning and development, and a deep understanding of the state and perspective of using ...
... relationships that could have appeared to influence the work reported in this paper. Acknowledgments Our thanks to all experts who participated in the survey and contributed to the results presented here. This study was supported by the Ministry of Education, Science and Technological Development of ...Boban Pavlović, Dejan Ivezić, Marija Živković. "Prioritization of strategic measures for strengthening the security of supply of the Serbian natural gas sector" in Energy Policy, Elsevier BV (2020). https://doi.org/10.1016/j.enpol.2020.111936
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Middle Triassic stepwise deepening and stratigraphic condensation associated with Illyrian volcanism in the Durmitor Mountain, Montenegro
Milica Mrdak, Martin Đaković, Hans-Jürgen Gawlick, Nevenka Đerić, Ioan I. Bucur, Milan Sudar, Mileva Milić, Damjan Čađenović (2024)... Belgrade, SRB-11000, Serbia; A-8700, Austria ŠSerbian Academy of Sciences and Arts, Knez-Mihailova 35, Belgrade, SRB-11000, Serbia “Geological Survey of Montenegro, Jaglike Adžić bb, Podgorica, MNE-81000, Montenegro (Manuscript received September 15, 2023; accepted in revised form January 5, 2024; ...
... org/10.1007/s00531-019-01714-w Epstein A.G., Epstein J.B. & Harris L.D. 1977: Conodont Color Alteration Index to Organic Metamorphism. Geo/ogica/ Survey Professional paper 995, 1—27. https://doi.org/10.3133/pp995 Feist-Burkhardt S., Gotz A.S., Szulc J., Borkhataria R., Geluk M., Haas J., Hornung ...Milica Mrdak, Martin Đaković, Hans-Jürgen Gawlick, Nevenka Đerić, Ioan I. Bucur, Milan Sudar, Mileva Milić, Damjan Čađenović. "Middle Triassic stepwise deepening and stratigraphic condensation associated with Illyrian volcanism in the Durmitor Mountain, Montenegro" in Facies, Springer Science and Business Media LLC (2024). https://doi.org/10.1007/s10347-024-00683-0
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Hidrogeohemijska valorizacija esencijalnih mikroelemenata mineralnih voda Srbije
Jana S. Stojković (2013-09-25)Mineralne vode još od davnina privlače pažnju ljudi i to kako u pogledu istraživanja iproučavanja, tako i u pogledu njihovog iskorišćavanja. Naročito je važno poznavanjesadržaja mikroelemenata u njima, jer su to komponente njihovog hemijskog sastavakoje ih odvajaju od tzv. „običnih“ malomineralizovanih voda.U ovom radu proučavani su odabrani esencijalni mikroelementi (fluor, bor, litijum,kalijum, stroncijum i silicijum), u mineralnim vodama Srbije, pri čemu je analiziranopreko 130 uzoraka mineralnih voda iz različitih geoloških sredina, to jest hidrogeološkihrejona. Cilj ovog istraživanja bio je ...esencijalni mikroelementi, faktori migracije, zakonomernosti rasprostranjenja, hidrogeohemijski procesi, multivarijantna statistička analiza, mineralne vode SrbijeJana S. Stojković. "Hidrogeohemijska valorizacija esencijalnih mikroelemenata mineralnih voda Srbije" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-09-25)
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Отпад из процеса сагоревања угља као сировина за добијање елемената ретких земаља
Бојан Земљак (2024)Због великог броја индустрија у којима се користе ови ресурси, глобална економија се у великој мери ослања на елементе ретких земаља. Елементи ретких земаља су есенцијална сировина — материјал за развој савремених технологија, али у односу на њихову огромну потражњу, њихово вађење је ограничено и повезано је са значајним утицајима на животну средину. Због њихове ограничене доступности, проблема који се јављају при процесима експлоатације, све више и више земаља почиње да тражи повољније могућности вађења елемената [REE] из секундарних ...... – errn. Heavy rare earth elements . DIUPAC]| – eprrn. Infernational Union of Pure and Applied Chemistry [USGS] – egrn. Unites States Geological Survey .· [HHS] – epHrm. Hydrophobichydrophilic separator · [RO] – eHrn. Reverse osmosis .· [NF] – egrn. Nanofiltration . [ELM] – eprm. Emulsification ...
... recovery from coal fly ashes. Metals, 11(1), p.142. 17 IIpeMa I eoJIOHmIKOM 3aBOJy CjeyHbeHHx AMepHukKux /pjKaBa (eHrn. Umifes States Geological Survey — [USGS] (p. D011S009R002), cBerckH pe3epBe cy JOOBOJBHC 30 3A4JOBOJbeMbC Hpec/iBHDeHe HOTpajKMKbc, aJIH CBCTCKa HpOM3BOJUba HcC 3aJlOBOJbaBa TpeHyTHy ...
... consumption in Australia. Current Research in Environmental Sustainability, 4, p.100157. [117] Eklund, E., 2015. Mining in Australia: An historical survey of industry-community relationships. 7he Extractive Industries and Society, 2(1), p.177-188. [118] Vestergaard, C., 2015. Governing uranium in ...Бојан Земљак. Отпад из процеса сагоревања угља као сировина за добијање елемената ретких земаља, 2024
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Projekcija razvoja osmatračke mreže podzemnih voda u Republici Srbiji
Petar Dokmanović, Zoran Stevanović, Saša Milanović, Bojan Hajdin, Vesna Ristić-Vakanjac, Veljko Marinović (2016)Petar Dokmanović, Zoran Stevanović, Saša Milanović, Bojan Hajdin, Vesna Ristić-Vakanjac, Veljko Marinović. "Projekcija razvoja osmatračke mreže podzemnih voda u Republici Srbiji" in Vodoprivreda 48 no. 279-281, Beograd : Srpsko društvo za odvodnjavanje i navodnjavanje (2016)
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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 ...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
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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 operation) on the conveyor drive, duc to its relatively large distance from the center of gravity of the electromotor. 2. Effect of high vibrations on electromotor as a result of poor condition of mount support A bucket wheel excavator is a ...
... the following ways: — The gearbox and electromotor are mounted on a long beam, such that the structural support is far away from thc center of gravity of the clectromotor and the drive assembly is on the boom with which it moves. This particular case is shown in Fig. 1, which is a photograph of ...
... vibrations were monitored. — The gearbox and electromotor are on a short beam, such that the structural support is roughly below the center of gravity of the electromotor. Thc drive assembly is on the boom and moves along with it. — The gearbox and electromotor are on a fixed mount – bottom beam ...Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović. "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" in Journal of Vibroengineering (2017). https://doi.org/10.21595/jve.2016.17321
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Environmental Energy Security Indicators as Tools for Environmental Protection
Еколошка прихватљивост је постала незаменљив синтезни показатељ сваке валидне енергетске анализе у последње две-три деценије. Енергетска безбедност је у директној хармонији с еколошком прихватљивошћу кроз многе прописане политичке циљеве, економске користи, правне тековине итд. Индикатори еколошке сигурности представљају један од основних елемената за одређивање енергетске безбедности и снажне алате за усмеравање енергетског сектора ка одрживом развоју. У овом раду, анализа је била концентрисана на показатеље енергетске безбедности у области животне средине који се односе на сектор природног гаса у ...енергетска безбедност, еколошки енергетски индикатори, заштита животне средине, еколошка прихватљивостAleksandar Madžarević, Dejan Ivezić, Marija Živković , Miloš Tansijević. "Environmental Energy Security Indicators as Tools for Environmental Protection" in Mining and Environmental Protection-MEP 2019, University of Belgrade, Faculty of Mining and Geology (2019)
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Some examples of interactions between certain rare earth elements and soil
Zlatko Nikolovski, Jelena Isailović, Dejan Jeremić, Sabina Kovač, Ilija Brčeski. "Some examples of interactions between certain rare earth elements and soil" in Journal of the Serbian Chemical Society, National Library of Serbia (2021). https://doi.org/10.2298/JSC211006095N
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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 ...Стефан Петровић, Наталија Батоћанин. "Aлтерације перидотита контролисане карактером флуида на примеру харцбургита Рудника - Серпентинизација или талкизација?" in Записници српског геолошког друштва, Српско геолошко друштво, Београд (2020)
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Hydrogeochemical distribution of Ca and Mg in groundwater in Serbia
... of different compounds of Ca and Mg in natural waters used in therapeutic treatment or as food (bottled waters) D. Sziwa,T. Latour & M. Drobnik A survey of Ca and Mg in thermal springs ofWestAfrica: lmplications for drinking and bathing rherapy K. Nghorgbu, K. Schoe neich,l. Ponikowsko,T. Latour & ...Petar Papić, Jovana Milosavljević, Marina Ćuk, Rastko Petrović . "Hydrogeochemical distribution of Ca and Mg in groundwater in Serbia" in Groundwater: Occurrence and Significance for Human Health, CRC Press, Balkema - Taylor & Francis Group (2014)
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Distribution of major and trace elements in the Kovin lignite (Serbia)
Dragana Životić, Olga Cvetković, Predrag Vulić, Ivan Gržetić, Vladimir Simić, Konstantin Ilijević, Biljana Dojčinović, Suzana Erić, Bogdan Radić, Sanja Stojadinović, Snežana Trifunović (2019)geochemical and mineralogical study was performed on lignite samples from the Upper Miocene Kovin deposit, hosting three coal seams. The Kovin lignite is characterized by high moisture content, medium to high ash yield, medium to high sulphur content and a relatively low gross and net calorific value. The mineralogical composition, and major and trace element contents were determined by X-ray diffraction, scanning electron microscopy with energy dispersive Xray spectroscopy (SEM-EDS) analyses, and inductively coupled plasma optical emission spectrometry (ICP-OES). ...Dragana Životić, Olga Cvetković, Predrag Vulić, Ivan Gržetić, Vladimir Simić, Konstantin Ilijević, Biljana Dojčinović, Suzana Erić, Bogdan Radić, Sanja Stojadinović, Snežana Trifunović. "Distribution of major and trace elements in the Kovin lignite (Serbia)" in Geologia Croatica, Croatian Geological Survey (2019). https://doi.org/10.4154/gc.2019.06
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Underground loading-haulage equipment selection with application of topsis method with different weighting methods of criteria
The choice of adequate mining machines is one of the most complex problems in the underground exploitation of mineral raw materials. The weight of such a decision is reflected in the high prices of these machines and the occurrence of even greater costs during their use if their choice was wrongly conceived. There are numerous examples from practice in which such decisions were made solely on the basis of comparing the prices of machines, without considering any of the ...utovarno-transportna mehanizacija, izbor, TOPSIS, entropija, standardna devijacija, težina kriterijumaVladimir Krivošić, Luka Crnogorac, Rade Tokalić. "Underground loading-haulage equipment selection with application of topsis method with different weighting methods of criteria" in Underground mining engineering, University of Belgrade - Faculty of Mining and Geology (2024)
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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 ...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
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Regional Debris Flow Hazard Assessment of the Grdelica Gorge (Serbia)
Miloš Marjanović, Biljana Abolmasov, Jelka Krušić, Uroš Đurić. "Regional Debris Flow Hazard Assessment of the Grdelica Gorge (Serbia)" in Progress in Landslide Research and Technology, Volume 3 Issue 1, Springer Cham (2024). https://doi.org/https://doi.org/10.1007/978-3-031-55120-8_15