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Упит dcterms_subject_txt:top-down method

508 items

  • Indeksi kontrole održavanja i korišćenja rotornog bagera

    Jovana Mitrović, Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić (2023)
    Razvoj površinske eksploatacije se u velikom stepenu zasniva na svestranoj mehanizaciji rudarskih radova. Kako bi se zadovoljili potrebni kapaciteti, neophodna je primena savremene mehanizacije, velikih kapaciteta i pouzdanosti u radu. Naime, sa stepenom povećanja mehanizovanosti radova smanjuje se broj zaposlenih radnika, povećava produktivnost rada, smanjuju troškovi po jedinici proizvoda, a samim tim i povećava ekonomičnost površinske eksploatacije. Predmet istraživanja su rotorni bageri SRs 1200 koji predstavljaju samohodne mašine kontinuiranog dejstva namenjene za otkopavanje jalovine i korisne supstance na površinskim ...
    rudarstvo, rotorni bager, indeksi održavanja, indeksi korišćenja, TOPSIS

  • Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?

    Nikola Stanković, Taras Gerya, Vladica Cvetković, Vesna Cvetkov (2024)

  • Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes

    Nevenka Gligorijević, Aleksandar Mijatović, Sandra Aranđelović, Rada Baošić (2021)
    Istraživanje kompleksa bakra kao potencijalnih antikancerogenih agenasa nudi ohrabrujuće perspektive u odnosu na komplekse platine (II) računajući na smanjenu toksičnost, novi mehanizam delovanja, različit spektar aktivnosti i perspektivu neunakrsne rezistencije. Kompleksi Šifovih baza bakra(II) koji sadrže tetradentatne ligande acac2en tipa (acac2en (1); tfacac2en (3), acactfacacen (4), acacphacacen (6)) pokazali su važnu antioksidativnu aktivnost, visok potencijal za interakciju sa HSA i DNK, u prethodnim studijama. Zbog toga je bilo interesantno ispitati i uporediti potencijal antikancerogene aktivnosti in vitro, u odnosu ...
    Bakar(II) kompleksi, citotoksičnost, ćelijski ciklus

  • Synthesis, characterization and photocatalytic examination of Co0.9Ho0.1MoO4 nanopowders

    Milena Rosić, Maja Milošević, Maria Čebela, Vladimir Dodevski, Vesna Lojpur, Radomir Ljupković, Aleksandra Zarubica (2023)
    ... electron microscopy (FESEM), and nitrogen adsorption method. The photocatalytic activity of acquired Cop.Hop , MoO, nanopowders was estimated by the photocatalytic degradation of crystal violet in aqueous solution. A simple and effective . method for controlling: the composition and morphology of ...

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

    Nikola Stanković, Vesna Cvetkov, Vladica Cvetković (2024)

  • Temperature induced evolution of nanostructured Ni0.9Zn0.1O

    Kremenović Aleksandar, Antić Bratislav, Vučinić-Vasić Milica, Colomban Philippe, Jovalekić Čedomir, Bibić Nataša, Kahlenberg Volker, Leoni Matteo (2010)
    The crystal structure and microstructure of as-prepared and annealed Ni0.9Zn0.1O were refined at room temperature in both the Fm (3) over barm and R (3) over barm space groups. It is shown that below the Neel point (458 K), where magnetic ordering triggers the presence of a trigonal strain, the common usage of a higher-symmetry non-admissible space group for crystal structure and microstructure analysis via the Rietveld method may result in both an incorrect structure description and incorrect microstructure ...

  • Resource-based WordNet Augmentation and Enrichment

    Ranka Stanković, Miljana Mladenović, Ivan Obradović, Marko Vitas, Cvetana Krstev (2018)
    In this paper we present an approach to support production of synsets for SerbianWordNet(SerWN)byadjustingPrincetonWordNet(PWN)synsetsusing several bilingual English-Serbian resources. PWN synset definitions were automatically translated and post-edited, if needed, while candidate literals for Serbian synsets were obtained automatically from a list of translational equivalents compiled form bilingual resources. Preliminary results obtained from a setof1248selectedPWNsynsetsshowthattheproducedSerbiansynsetscontain 4024 literals, out of which 2278 were offered by the system we present in this paper, whereas experts added the remaining 1746. Approximately one half of ...
    WordNet, bilingual resources, term alignment, parallel lists
    ... EWN. Bentivogli and Pianta (2003) proposed a method for extending MultiWordNet1 with phrases, by extracting them from bilingual dictionaries and corpora with techniques similar to those used for collocation extraction. In (Bhingardive et al., 2014) a method for Sanskrit WordNet extension using a Sanskrit ...
    ... is similar. Each term comes with a name, definition, an optional list of synonyms, abbreviations and a bibliographic source. Each term, except the top term in the dictionary tree, has only one hyperonym term, but it can have an arbitrary number of hyponym terms. However, in our approach we have used ...
    ... one of the common approaches to wordnet enhancement is the use of a developed wordnet (most commonly PWN) as the basic source for enrichment, and a method for aligning the synsets of the two wordnets, such as the ILI. Automatic alignment of synsets belonging to different languages is closely related ...

  • 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
    ... – These use sound waves to measure flow. There are two main methods: a.Doppler method - Measures changes in the frequency of the sound wave caused by the movement of particles in the fluid. b.Transit-time method - Measures the time it takes for the sound wave to travel between two sensors, which ...
    ... dataset through sampling. There are two basic approaches: 1.Undersampling: In this method, only samples from the majority class are used to achieve a balance with the minority classes. 2.Oversampling: This method adds copies of examples from the minority class to achieve balance between classes ...
    ... examples from the minority classes to achieve a more balanced data distribution. Additionally, there is a method for generating synthetic samples to reduce class imbalance. One popular method is SMOTE (Synthetic Minority ' Over-sampling Technique), which creates synthetic samples from the minority ...

  • Application of the Fuzzy theory in the evaluation of operating parameters of auxiliary mechanization on open-cast coal mine, case study: pipelayers

    Stevan Djenadić, Miloš Tanasijević, Filip Miletić, Predrag Jovančić (2022)
    Achieved operating parameters are the main indicator of the work quality and selection of mining machines. The effectiveness of a coal mine is correlated with the availability of basic and auxiliary machines. The main task of auxiliary machines in lignite mines is to achieve optimal working conditions. From an economic point of view, auxiliary machines generate up to 20% of the lignite mines' total costs. These are the primary reasons for analyzing their current work and making decisions in ...
    upotrebni kvalitet, fazi teorija, rudarske mašine

  • Primena AHP и WoEmetode u proceni podložnosti terena na kliženje za područje opštine Krupanj

    Biljana Abolmasov, Jelka Krušić, Katarina Andrejev, Miloš Marjanović, Ranka Stanković, Uroš Đurić (2017)
    ... municipality scale, and can be successfully used for further landsli- de risk assessment or large scale planning. Key words: landslides, AHP method, WoE method, landslide susceptibility map Adresa autora: 1,2,3,4 i 5) Univerzitet u Beogradu, Rudarsko-geološki fakultet, Đušina 7, 11000 Beograd 6) ...
    ... watershed, west Nepal. Computers&Geosciences 52, pp.398-408, 2013. [15] Komac M. A landslide susceptibility model using the Analytical Hierarchy Process method and mul- tivariate statistics in perialpine Slovenia. Geomorp- hology 74, pp.17-28, 2006. [16] Kubat I, Mojsilović S, Veljković D, Reljić D, Strajin ...
    ... Sarajevo 1968. [17] Marjanović M, Abolmasov B, Đurić U, Zečević S. Impact of geoenvironmental factors on landslide susceptibility using an AHP method: A case study of 246 IZGRADNJA 71 (2017) 7–10, 239–246 Fruška Gora Mt., Serbia. Annales Geologiques de la Peninsule Balkanique74, pp. 91-100 ...

  • Parameter determination of soil oscillation law using quotient of the relative growth increments of oscillation velocity and reduced distances at “Nepričava“ open pit mine

    Suzana Lutovac, Sanja Bajić, Marina Ravilić, Radmila Gaćina (2015)
    ... characteristics of the soil, being determined on the basis of test blasting for the specific work environment. In this paper, an analysis of the method for the determination of soil oscillation law parameters has been conducted, suggested by Profesor M. A. Sadovski. The applicability of this law ...
    ... Open Pit Mine being carried out in order to exploit the deposit. To determine parameters in the equation of Sadovski, in addition to the common method of least squares, another model was applied. Thereby, it has been stated that both models can be used to calculate the oscillation velocity of the ...
    ... number of ways, i.e. models, thereby using values obtained by experimental measurements. Determination of parameters by model 1 The smallest square method is mainly used to obtain the parameters K and n which represents a common model (Simeunović, 1985). Determination of parameters by model 2 Proceeding ...

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

    Nikola Stanković, Vesna Cvetkov, Vladica Cvetković (2024)

  • Numerical Modeling and Simulation of the Effectiveness of Groundwater Source Protection Management Plans: Riverbank Filtration Case Study in Serbia

    Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin, Dragan Pamučar (2022)
    The paper describes the establishment and testing of an algorithm for developing sustainable management plans associated with groundwater source protection against potential pollutants and discusses the effectiveness of individual systems. The applied methodology pertains to groundwater resource management, particularly those cases that involve riverbank filtration. Namely, groundwater (numerical) modeling is employed to examine the groundwater regime and balance, as well as to create protection systems and illustrate their effectiveness. Particle tracking analysis is used to study pollutants’ travel and ...
    Water Science and Technology,Aquatic Science,Geography, Planning and Development,Biochemistry

  • Contents of potentially toxic elements in residual soils of a long-term mining region: a key study from Central and Western Serbia

    Milun Jovanović, Dejan Prelević, Vidojko Jović, Danica Srećković-Batoćanin, Snežana Branković (2022)
    Regional geochemical research of residual soil was conducted in an area of about 20,000 km2 in the region of Central and Western Serbia, where six metallogenetic zones and mining since ancient times have been documented. The geochemical background variation in the residual soil was established upon the contents, spatial pattern and natural background of potentially toxic elements (PTEs). The limits of natural background values (mg·kg-1) were determined by the integral method. Our data show that anomalous concentrations of As, ...
    prostorna distribucija, toksični elementi, rezidualno tlo, procena rizika

  • 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

  • Probabilistic analysis of anisotropic rock slope with reinforcement measures

    Zoran Berisavljević, Dušan Berisavljević, Miloš Marjanović, Svetlana Melentijević (2023)
    During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the ...
    povratna analiza, tehnika optimizacije, verovatnoća loma, anizotropija čvrstoće

  • Application of the PROMETHEE and VIKOR methods for selecting the most suitable carbon dioxide geological storage option

    Lola Tomić, Vesna Karović Maričić, Dušan Danilović, Branko Leković, Miroslav Crnogorac (2019)
    CO2 storage in geological formations is one of the leading solutions for mitigation of greenhouse gas emissions. Types of geological formations that can be used for CO2 storage, that are discussed in this paper are: depleted oil and gas reservoirs, saline aquifers and injection CO2 in partially depleted oil reservoirs for enhanced oil recovery (EOR–CO2 method). In order to select the most suitable geological storage of CO2, the ranking of these storage options was performed using two methods of ...
    Prometej, vikor, višekriterijumsko odlučivanje, geološko skladištenje

  • Differently shaped nanocrystalline (Fe, Y)3O4 and its adsorption efficiency toward inorganic arsenic species

    Biljana P Dojčinović, Boštjan Jančar, Lotfi Bessais, Aleksandar Kremenović, Nataša P Jović-Jovičić, Predrag T Banković, Dalibor M Stanković, Miloš Ognjanović, Bratislav V Antić (2019)
    Herein we report effects of partial substitution of Fe3+ by Y3+ in magnetite (Fe3O4) on morphology and inorganic arsenic species adsorption efficiency of the Fe3−xYxO4 nanoparticles formed. The series of Fe3−xYxO4 (x=0.00, 0.042 and 0.084, labeled as Y00, Y05 and Y10, respectively) was synthesized using co-precipitation followed by microwave-hydrothermal treatment (MW) at 200°C. With increase of yttrium content(xvalue), both the morphological inhomogeneity of the samples and the fraction of spinel nanorods as compared to spinel pseudospherical particles increased. By ...
    microstructure, microwave-hydrothermal synthesis, adsorption, magnetic nanoparticles, arsenic

  • A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice

    Nikola Lilić, Ivan Obradović, Ranka Stanković (2002)
    Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper, we ...
    ... for ventilation system branches 4–7 and 6–7. The air flow distribution shown in Fig. 14 was determined using the Hardy-Cross method. The results obtained by this method show that the required air distribution can be achieved by building booster fans in branches 4–7 and 6–7 (176.81 Pa and 56.56 Pa ...
    ... The SimVent simulator of complex mine ventilation networks based on the Hardy-Cross method was used for the calculation of the fitness for the population. Table 1. The air distribution obtained by standard method. Branch Inlet-Outlet R(Ns2/m8) Q(m3/s) p(Pa) NVP(Pa) pr(Pa) pbf(Pa) No. Node 1 1–2 0 ...
    ... the coupling of various artificial intelligence (AI) methods in the solution of complex problems that cannot ade- quately be solved by a single AI method. The core of the implemented approach is a hybrid intelligent system (HIS) developed with the help of available AI software libraries. 2. The INVENTS ...

  • 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