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Упит dcterms_subject_txt:field data analysis

1275 items

  • The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers

    Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović (2019)
    One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...
    open-cast coal mine, auxiliary works, bulldozers, optimization, availability
    ... costs of fuel and lubricants, transportation cost from manufacturer, interest rates, etc. Analysis was performed according to recommended method for evaluation of hourly ownership and operational costs, including data on auxiliary machines (Caterpillar and Komatsu methods). Integration of this information ...
    ... 50% of all auxiliary equipment costs. This implies the necessity for detailed analysis ог all parameters of these machines, including. current and historic trends, as well as some technical capabilities. Such ап analysis would enable better forecasting ог their operation. Dozer's life оп the open-cast ...
    ... quality, ореганпр conditions, maintenance quality, operating quality, апа others. Empirical data shows that dozer's life on open-cast mines is 25-30,000 hours, i.e. around 10 years of operation. However, some data also shows that dozers after 6% year ог operation аге having lesser efficiency which is ...

  • Smanjenje sleganja plitkih temelja primenom mikrošipova

    Slobodan Ćorić, Dragoslav Rakić (2021)
    Mikrošipovi su šipovi malog prečnika koji se grade tako što se u tlu specijalni postupkom formira bušotina koja se zatim armira i injektira. Njihov prečnik je najčešće 150 – 300 mm, a dužina može da bude i više desetina metara. Mikrošipovi mogu da se grade u svim vrstama tla i mogu da budu vertikalni i kosi. Oni se, stoga, koriste kao zamena za konvencionalne šipove i ankere. Primena mikrošipova u fundiranju predstavlja jedan savremeni način izgradnje i sanacije temelja/objekata. ...
    mikrošipovi, sleganje plitkih temelja i mikrošipova, krutost tla i mikrošipova

  • Hydrochemical features and their controlling factors in the Kucaj-Beljanica Massif, Serbia

    Fen Huang, Ljiljana Vasic, Xia Wu, Jianhua Cao, Saša Milanovic (2019)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • Investigation of quantitative indicators of anisotropy based on longitudinal elastic waves propagation velocities with uncertainty

    Miloš Gligorić, Jelena Majstorović, Suzana Lutovac (2018)
    ... statistical analysis is shown in this section. Finally, Section 6 explains the conclusion of our study. 2 BASICS OF INTERVAL NUMBERS The devices for measuring ultrasonic waves are constantly exposed to external influences such as adverse weather conditions, inaccessible field and inexperience ...
    ... compute these indicators. Uncertainty of input parameters implies defining a boundaries above these data thereby increasing the flexibility and reliability of the computational process. Comparative analysis between these samples shows a highly difference of quantitative indicators of anisotropy. Isotropic ...
    ... mean KAj,mean 12 Gligorić M., Majstorović J., Lutovac S. Statistical analysis of the obtained results for isotropic and anisotropic samples is presented in the Table 1 and Table 2. Table 1 Statistical analysis of the obtained results for isotropic samples Statistical parameter 𝐷𝐼𝑖 ...

  • Korelacija magnetnog susceptibiliteta i sadržaja metala u flotacijskom jalovištu

    Filip Abramović, Vesna Cvetkov, Aco Ilić, Dragana Životić (2022)
    Procena metala u rudama, jalovištu i zemljištu se tradicionalno određuje hemijskim metodama kao što su Rengen fluorescentna analiza (XRF), Instrumentalna neutronska aktivaciona analiza (INAA) i Masena spektrometrija induktivno spregnute plazme (ICP-MS). Neke od pomenutih metoda su veoma zahtevne i skupe, te se nametnula potreba ka traženju jeftinijeg alata za brzu procenu prisustva pojedinih metala. Tokom poslednjih nekoliko decenija, mnoge studije su pokazale da su magnetna merenja dovoljno osetljiva da detektuju magnetni signal feromagnetnih materijala, a samim tim i metala ...
    flotacijsko jalovište, makroelementi, magnetna merenja

  • Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS

    Predrag Jovančić, Ignjatović Dragan, Đenadić Stevan (2021)
    Jedan od osnovnih zadataka na površinskim kopovima uglja je ostvarivanje zadovoljavajućeg vremenskog i kapacitetnog iskorišćenja kontinualnih sistema. Da bi se to postiglo, neophodno je izvršiti izmene u postojećoj strategiji održavanja. Preduslov je uvođenje agregatne zamene vitalnih delova na rudarskim mašinama. Benefiti su višestruki. Očekivani rezultati ovakvog pristupa su: smanjenje zastoja i povećanje vremena rada; direktne materijalne uštede; bolja organizacija rada; racionalizaciju radioničkih i magacinskih kapaciteta; povećanje vrednosti mašina. Da bi se uvela agregatna zamena neophodne su investicije za nabavku ...
    agregatne zamene, održavanje, mehanizacija, Benefit Cost analiza

  • Synthesis, magnetic, thermal and structural properties of Co(II), Ni(II) and Cu(II) complexes containing isophthalato ligands

    Jelena Rogan, Dejan Poleti, Ljiljana Karanović, Zvonko Jagličić (2011)
    A series of novel ternary Co(II), Ni(II) and Cu(II) complexes containing 2,20-dipyridylamine (dipya), 2,20-bipyridine (bipy), and 1,10-phenanthroline (phen), as aromatic diamine ligands, and dianion of isophthalic acid (ipht) have been prepared by ligand exchange reactions from diluted H2O/EtOH solutions. The complexes were characterized by elemental analysis, IR spectroscopy, magnetic susceptibility measurements and TG and DSC analysis. Three complexes, Cu(dipya)(ipht)H2O (1), Co(dipya)(ipht)2H2O (2) and Cu(ipht)(phen)2H2O (5) are polymeric with bis-monodentate ipht, while the other two complexes M(bipy)(ipht)4H2O, M@Co(II) (3) and ...
    комплекси прелазних метала, карбоксилатни лиганди, N-лиганди, кристална структура, магнетна својства

  • Automatic construction of a morphological dictionary of multi-word units

    Cvetana Krstev, Ranka Stanković, Ivan Obradović, Duško Vitas, Miloš Utvić (2010)
    The development of a comprehensive morphological dictionary of multi-word units for Serbian is a very demanding task, due to the complexity of Serbian morphology. Manual production of such a dictionary proved to be extremely time-consuming. In this paper we present a procedure that automatically produces dictionary lemmas for a given list of multi-word units. To accomplish this task the procedure relies on data in e-dictionaries of Serbian simple words, which are already well developed. We also offer an evaluation ...
    electronic dictionary, Serbian, morphology, inflection, multiwordn units, noun phrases, query expansion
    ... covered by rules. 8 Authors Suppressed Due to Excessive Length 4 Analysis and Evaluation of the Strategy We have performed the analysis and evaluation of our strategy in two steps. In the first step we applied the strategy to the same data that we used to produce it, that is our initial DELAC dictionary ...
    ... categorization in [8]) in terms of the information they offer and the methodology used to produce them (without statistical engineering). 2 Analysis of Initial Data We based the development of the automated procedure for DELAC construc- tion on the initial dictionary of MWUs, which contained 3195 lemmas ...
    ... multi-word units. To accomplish this task the procedure relies on data in e-dictionaries of Serbian simple words, which are already well developed. We also offer an evaluation of the proposed procedure on sev- eral different sets of data. Finally, we discuss some implementation issues and present how the ...

  • Using gravity data to define structural correlation affecting the formation of Neogene basins

    Snežana Ignjatović, Ivana Vasiljević, Branisav Sretković, Milanka Negovanović (2023)
    A gravity survey can help to define the structural correlation in the study area. The structures that have influenced the development of Neogene basins can be defined using gravity data. By applying mathematical transformations to gravity data, the geological structures (faults, nappes, etc.) that impacted the formation of Neogene basins can be defined. We have taken the part of the Dinarides as the test region. The paper presents the results obtained using the procedure residual, vertical gradient, and total ...
    gravity survey, mathematical transformation, basin

  • Prezentacija projekta "Zaštita ležišta mineralnih sirovina kao osnova sigurnog snabdevanja mineralnim sirovinama u Evropi (safemin4europe)

    Vladimir Simić, Rade Jelenković, Dragana Životić, Zoran Miladinović, Stefan Petrović, Marija Petrović (2022)
    Harmonični ekonomski razvoj svake zemlje u velikoj meri zavisi od dostupnosti sirovina, naročito mineralnih sirovina. Obezbeđivanje njihove dovoljne količine na tržištu (ponude) je od vitalnog značaja za funkcionisanje različitih industrijskih grana koje proizvode različitu robu i opremu neophodnu za ispunjavanje životnih potreba stanovništva kao i za efikasnu poljoprivredu. Mineralne sirovine su neophodne za podršku ekonomskim aktivnostima na lokalnom, regionalnom, nacionalnom i međunarodnom nivou. Ovo su, istorijski, prve sirovine koje su počele da se koriste iz domaćih izvora, i u ...
    ležišta mineralnih sirovina, valorizacija, zaštićena područja, socijalni aspekti

  • Utilizing sewage wastewater heat in district heating systems in Serbia: effects on sustainability

    Marija Živković, Dejan Ivezić (2021)
    Transformation of the heating sector is recognized as being essential for ensuring reliable and afordable energy services provided with reduced consumption of energy sources and diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused ...
    рекуперација топлоте из отпадних вода, систем даљинског грејања, топлотне пумпе, енергетске уштеде, емисија угљендиоксида, енергетска безбедност, Србија
    ... includes determination of technical potential of waste heat based on data from existing waste- water treatment facilities and a simulation of heat energy production by heat pumps. The effects on sustainability are assessed through analysis of key performance indicators to provide deeper insight in energy ...
    ... in Serbia, while data about the potential of this energy source are lack- ing. This research proposes a methodology for the determination of the technical potential of waste heat from wastewater treatment facilities for use in district heating systems by heat pump application. Data from existing wastewater ...
    ... simulated to explore how increasing the share of heat pump production influences DH systems. Data on heat pump performance in an Olympic village in Vancouver are given in Fiore and Genon (2014). Technical data and analyses of effectiveness of a heat pump installa- tion in Vladivostok are discussed in ...

  • Improving Document Retrieval in Large Domain Specific Textual Databases Using Lexical Resources

    Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović (2017)
    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 ...
    ... the past decade. The aim of this information system was primarily to establish an object- oriented database for digital archiving of geologic data in the field of general geology, exploration of mineral deposits, hydrogeology and engineering geology, as a modern and efficient information basis for planning ...
    ... most prominent multimedia content are the gallery of photos and movies, geoheritage, BEWARE GIS web portal for interactive landslide data management, hazard and risk analysis, and jeweler mineral resources. Textual databases, also known as catalogs, consist of projects, archival documents and bibliographies ...
    ... in database technology provide nowadays for management of large quantities of heterogeneous data. However, besides this engineering challenge— efficient management of such data, the “exploding world of Big Data” poses yet another, semantic challenge—finding and meaningfully combining information that ...

  • Rangiranja bagera za njihovu revitalizaciju primenom višekriterijumske analize

    Ivan Obradović, Dragan Ignjatović, Ranka Stanković, Ljiljana Ivković (2006)
    Obzirom da je na našim površinskim kopovima trenutno u eksploataciji veći broj rotornih bagera sa sličnim tehničkim karakteristikama i približno istom starošću postavlja se pitanje kako rangirati bagere, i kojim redom da se izvrši njihova revitalizacija. Za ocenu stanja i rangiranje ovako velikog broja bagera najpogodnije se pokazalo korišćenje višekriterijumskih metoda sa višeatributnom ocenom, odnosno bodovanje referentnih indikatora stanja bagera na osnovu ekspertske ocene. U ovom radu prikazan je metodološki pristup koji je korišćen prilikom izrade Studije «Produžetak radnog ...
    rotorni bageri, revitalizacija, rangiranje, višekriterijumska analiza
    ... 7, 11000 Beograd Sažetak: Obzirom da je na našim površinskim kopovima trenutno u eksploataciji veći broj rotornih bagera sa sličnim tehničkim karakteristikama i približno istom starošću postavlja se pitanje kako rangirati bagere, i kojim redom da se izvrši njihova revitalizacija. Za ocenu ...
    ... postavlja pitanje kako rangirati ove bagere, odnosno kojim redom da se izvrši njihova revitalizacija, tj. produžetak radnog veka. Ulazak u remont radi revitalizacije i modernizacije zasniva se na proceni tehničkog stanja bagera, tako da je pre početka revitalizacije neophodno izvršiti brojna i detaljanja ...
    ... konačnih numeričkih ocena. U Tabeli 3 date su konačne numeričke ocene i rang lista bagera za vrednosti atributa iz Tabele 1 i zadate težinske faktore pλ iz Tabele 2. Kao što se vidi iz tabele 3 bager pod rednim brojem četiri ima najslabiju ocenu i stoga se predlaže se da ovaj bager prvi uđe u pripremne ...

  • The analysis of the geothermal energy capacity for power generation in Serbia

    Jana Stojković, Goran Marinković, Petar Papić, Mihailo Milivojević, Maja Todorović, Marina Ćuk (2013)
    Renewable Energy, Sustainability and the Environment
    ... 04:08:19 The analysis of the geothermal energy capacity for power generation in Serbia Jana Stojković, Goran Marinković, Petar Papić, Mihailo Milivojević, Maja Todorović, Marina Ćuk Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] The analysis of the geothermal ...
    ... � � � � 731 452 27315 [ . log )] . (3) Stojkovi}, J. S., et al.: The Analysis of the Geothermal Energy Capacity for ... 970 THERMAL SCIENCE: Year 2013, Vol. 17, No. 4, pp. 969-976 Stojkovic, J. S., et a/.: The Analysis of the Geothermal Energy Capacity for ... 970 THERMAL SCIENCE: Year 2013, Vol ...
    ... mometer should be cautiously used with the water rich in CO2. A diagram (fig. 3) of the Na-K-Mg geothermometer shows the tested groundwater in the field of partial equilibrium, below the complete equilib- rium that determines Na/K geothermome- ter variation by Giggenbach. Scatters to- wards magnesium ...

  • Development of integrated fuzzy model for mine management optimization

    Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)
    fuzzy logika, višekriterijumsko odlučivanje, ocenjivanje eksperata
    ... M. DEMIRCAN, C. KAHRAMAN (2005) Operating, system selection using fuzzy replacement analysis and analytic hierarchy process, Int. J. Prod. Econ., 97, 89-117. | CHEN H. (2006) Applications of Fuzzy Logic in Data Mining Process. In: Bai Y., Zhuang H., Wang D. (eds), Advanced Fuzzy Logic Technologies ...
    ... Information sciences, 8, 199—249. Š| CHANG D. Y. (1996) Applications of the extent analysis method on fuzzy AHP, Rur. J. Oper. Res., 95, 649 655. “} ZnU K., Y. JING, D. CHANG (1999) A discussion on extent analysis method and applications of fuzzy AHP, Eur. J. Oper. Res., 116, 450 456. TOLGA FE ...
    ... results in efficient mining: as well as higher productivity and market competitiveness. OConclusion. A modern approach to investigations in the field of geoscience and mine management was presented in the paper. The selection and design of a mining: technology is one of the most complex tasks ...

  • Surface functional groups and degree of carbonization of selected chars from different processes and feedstock

    Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)
    The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...
    Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS
    ... spectroscopy analysis of biochar. In: Singh B, Camps-Arbestain M, Lehmann J, editors. Biochar: A guide to analytical methods, 1st ed., CRC Press/Taylor Francis Group, LLC, Boca Raton, FL, USA; 2017, pp. 229-244. Brewer CE, Unger R, Schmidt-Rohr K, Brown HC. Criteria to select biochars for field studies ...
    ... biochars made by fast pyrolysis. The latter are known to contain large amount oftar which can block the entrance to small pores [28,74]. Chemical analysis Data for the mass fraction X of the main elements related to the mass of the incinerated char are given in Table 2. The concentrations of other elements ...
    ... requires expensive equipment. It is there- fore no method for quality control, but it is valuable for an integrated evaluation of data from other methods (chemical analysis, XRD, FT-IR, Raman and SIP). The results strongly support the classification of the investigated chars by the production method ...

  • Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households

    Boban Pavlović, Dejan Ivezić, Marija Živković (2020)
    The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed. These two systems represent two different types of individual wood biomass heating systems. In the case of the firewood-based heating systems, it is analyzed a typical stove ...
    Grejanje, Analiza životnog ciklusa, Drvna biomasa, Individualni sistemi grejanja
    ... energy consumption of HSs is calculated by using data from the available Energy Agency of the Republic of Serbia’s (AERS) report on the comparative costs of housing heating in the annual report [17]. The AERS’s methodology is based on the analysis of a typical flat of 60 m2 that is heated to 20°C ...
    ... defined in the IPCC Assessment Report [16]. 3 THE SCOPE AND INVENTORY DATA The scope of this study is under ISO 14000 and it deals with the comparative LCA of HSs throughout all stages of HSs’ lifetime. The exact data on the structure of energy use for space heating by the fuel and type of ...
    ... 5%20Mtoe)*.&text=To%20fulfil%20the%20EU's%20climate,its%20use%20of%20fossil%20fuels https://www.unece.org/fileadmin/DAM/env/documents/2018/Air/WGSR/Roald_Wolters.pdf https://www.unece.org/fileadmin/DAM/env/documents/2018/Air/WGSR/Roald_Wolters.pdf http://biomasa.undp.org.rs/wp-content/uploads/2018/11/POSITIO ...

  • Structural characterization of traditional pottery produced from local clay, Rujište (Ražanj, Central Serbia), in an effort to preserve its geoheritage

    Maja Milošević, Biljana Đorđević, Alena Zdravković (2021)
    ... preservation of this type of intangible cultural heritage, inscribed in the National register of ICH and as geoheritage in Serbia as well. The analysis of the phase, mineral composition and structure of the clay body was performed by optical microscopy on cross-sections perpendicular to the vessel ...
    ... which is intimately mixed with clay of the illite type with a very smaller amount of detrital quartz and feldspar (Krstić et al., 1980). In the analysis of the thin sections made of the sample, the basic mass is observed, which represents a sintered fine-grained aggregate and binds large, often ...
    ... hydroxides are mostly present in the form of solid spheres sometimes of regular shape. The main focus of this investigation was the mineralogical analysis of the clay body used in the manufacture of traditional pottery, bread-baking pan called crepulja, prepared with raw local clays from Ražanj area ...

  • Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica

    Natalija Momirović, Ratko Kadović, Veljko Perović, Miloš Marjanović, Aleksandar Baumgertel (2019)
    Nature and Landscape Conservation, Soil Science, Agronomy and Crop Science, Water Science and Technology