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Упит dcterms_subject_txt:Timok Magmatic Complex

534 items

  • 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

  • Ventex: an expert system for mine ventilation systems analysis

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    roblems relating to mine ventilation systems analysis are usually of a very complex nature. They involve the estimation of numerous interdependent parameters pertaining to the network status, ventilation status, ventilation system stability, air current losses, climate conditions, gas state, fire risk and dangerous dust pollution risk. The solution to these problems relies, to a great extent, on numerical methods. With the development of computer technology these methods were incorporated as numerical routes in software packages, such as the mine ...
    expert system, mine ventilation

  • The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis

    Ljiljana Vasić, Dragana Ž. Živojinovic, Vladana Rajaković-Ognjanović, Huang Fen, Cao Jianhua (2021)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change

  • Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024

    Sanja Bajić, Dragoljub Bajić, Branko Gluščević, Radmila Gaćina, Josip Išek (2024)
    multi-criteria decision-making, definition of criteria, underground exploitation

  • Mine ventilation system planning using genetic algorithms

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    The most common problem in contemporary mining practice related to the planning and analysis of ventilation systems is the optimization of partially regulated air distribution in mine ventilation networks. This paper presents a two step optimization procedure for partly regulated air distribution in mine ventilation networks. The first step is the determination of air distribution in all branches using the well known Hardy-Cross method. In the second step the distribution and parameters of air flow regulators with minimum engaged ...
    coal, lignite, and peat; ventilation systems; coal mining; underground mining; ventilation; mathematical models; design; air flow; optimization; calculation methods

  • Да ли има трагова експлозивних ерупција у источном делу Лецког вулканског комплекса?

    Емилија Ниџовић, Владица Цветковић, Кристина Шарић (2023)
    вулканологија, комплекс, пирокластити

  • Da li ima tragova eksplozivnih erupcija u istočnom delu leckog vulkanskog kompleksa?

    Emilija Nidžović, Vladica Cvetković, Kristina Šarić (2022)

  • Analysis and visualization of geophysical well-logging data from closely spaced boreholes

    Branislav Sretković, Ivana Vasiljević, Dimitry Sidorov - Biryukov (2024)
    Geophysical logging measurements for determining the condition of the rock mass on the dam profile and locating the predisposed directions of water circulation and loss from the reservoir were conducted in four boreholes distributed at a close distance. The survey was carried out in a typical karst terrain, which is an additional challenge for defining the geological model, especially in terms of water retention. That kind of data set provides an excellent opportunity for a new approach to analysis ...
    well-logging in karst, water loss, data correlation, data fusion
    ... Karaman, Mileva Milić TeoxpoHounnoruja u HaoronnHa IFeojmoruja NEW INFORMATION ON THE AGE OF THE PEGMATITES OF CANISTE (PELAGONIAN METAMORPHIC COMPLEX), NORTH MACEDONIA Jvan Boev, Tena Ivanova Sijakova Sonja Lepitkova 12 19 27 32 35 42 49 Munepozioruja, Ilerpo.toruja u feoxeuja ...
    ... karst terrains is of particular importance when investigating the geological structure of the zone of the dams, especially taking into account the complex specificities of karst in terms of surface and underground water circulation, as well as stability and hazard assessment for large objects such ...
    ... mass and its karstified zones. SITE DESCRIPTION The investigation area belongs to the Dinaric-ophiolitic zone, one of the most outstanding and complex geological regions of the Dinaric karst. The dam site is located within an asymmetric tectonic trench formed by gravitational activation of the ...

  • Development of Open Educational Resources (OER) for Natural Language Processing

    Cvetana Krstev, Biljana Lazić, Ranka Stanković, Giovanni Schiuma, Miladin Kotorčević (2015)
    In this paper we present the development of an online course at the edX BAEKTEL platform named “Lexical Recognition in the Natural Language Processing (NLP)”. It is based on the course of the same name for PhD studies at the University of Belgrade, Faculty of Philology. There are not many courses in Computational Linguistics (CL) on OER platforms, and there is none in Serbian either for CL or NLP. We have developed this course in order to improve this ...
    E-Learning, Open Educational Resources, Computational Linguistics, Lexical Resources, edX
    ... sophisticated approaches. Besides simple regular expressions, graphs that represent the visualization of finite state automata (FSA) can be used for complex queries. Moreover, finite state transducer FSTs (FSAs with output) can be used for text transformation. The concept of e-dictionaries and ...
    ... expressions that enable string search at the level of characters – and graphs as a tool for visualizing regular expressions that facilitates more complex queries. 6. Advanced topics in the use of graphs are given, e.g. subgraphs and input variables. The later topics enable development of transducers ...
    ... multi-word unit (MWU) recognition are presented with emphasis on e-dictionaries of nominal MWUs, particularly their inflection that has to consider complex rules for MWU inflection in Serbian. 10. The use of powerful morphological mode is presented that enables the use of lexical resources at sub-word ...

  • Phase relations and physical indicators of municipal waste from old landfills in Serbia

    Dragoslav R Rakić, Irena G Basarić Ikodinović, Jovana M Janković, Tina D Đurić (2021)
    Due to certain similarities of municipal waste and soil, usually for the determination of basic parameters of physical state, laboratory and field tests which are common in geotechnical investigations are used. It is often to construct an apparatus for special purpose to perform some specific laboratory and field tests. Therefore, different values of indicators of municipal waste physical state can be found in the literature. The basic reasons should be found in different definitions and methods that researchers use ...
    municipal waste, moisture content, unit weight, specific gravity, grain size distribution, porosityGeneral Computer Science
    ... ions, which further complicate a comparison of obtained results. Unlike soil, determination of physical parameters of municipal waste is more complex, because of its extremely heterogeneous composition, consistency, biodegradability etc. In addition, physical properties of waste change over time ...
    ... definition called „S.W.A. - Tool'* (European Commission - EC, 2004). Unlike soil, determination of physical parameters of municipal waste is more complex, because of its extremely heterogeneous composition, consistency, biodegradability etc. (Vosniakos and Patronic, 2009). Therefore, data on the ...
    ... tested samples (Zekkos et al., 2006; Rakić, 2013). 3.4 Specific gravity Determination of the specific gravity on samples of municipal waste is complex because waste contains pores inside particles and between particles. In the literature certain terms can be found based on which specific gravity ...

  • A Mathematical Learning Environment Based on Serbian Language Resources

    Radojičić Marija, Obradović Ivan, Stanković Ranka, Utvić Miloć, Kaplar Sebastijan (2018)
    In recent years, in line with ever growing usage of Information technology, the learning environments are changing. The amount of available learning materials in various forms has increased. These new environments demand comprehensive learning systems, which enable management of the learning corpus with special attention paid to relevant lexical resources. In this paper we present the concept of a Mathematical Learning Environment in Serbian (MLES), which is based on a corpus of mathematical materials and various lexical resources, enabling ...
    mathematical content, text processing, mathematical formulae
    ... mathematical content. A specific use of the system is mathematical support in solving real life problems from engineering practice. To that end complex issues had to be resolved, such as mathematical text analysis, processing of mathematical content in different formats, search of mathematical materials ...
    ... search engine. To that end the solution uses linearization, transformation rules, generalization rules and ordering algorithm, which simplify the complex and highly symbolic mathematical structures into linear structures with well-defined symbols. This type of support for Serbian is still not available ...
    ... relevant engineering problems. Figure 3. MLES application 3. GOALS AND CHALLENGES Searching and processing mathematical materials is a complex problem. Standard text processors cannot recognize mathematical texts in a proper way. There is thus a need for developing new and adapting existing ...

  • A WebGIS Decision Support System for Management of Abandoned Mines

    Ranka Stanković, Nikola Vulović, Nikola Lilić, Ivan Obradović, Radule Tošović, Milica Pešić-Georgiadis (2016)
    ... decision-making itself when complex problems encompassing goals, criteria, sub-criteria and alternatives are solved. The method was devised in the 1970s by Saaty [13]. From the methodological point of view, AHP is a multi-criteria technique based on the decomposition of a complex problems into a hierarchy ...
    ... within the comprehensive planning Energies 2016, 9, 567 3 of 14 of further development of the broader domain, on the basis of different types of complex data, instead of partial unharmonized individual projects and plans with contradictory solutions; (b) funds savings for the work on remediation and ...
    ... project activities preformed within the development of the cadastre of abandoned mines in Vojvodina and the accompanying WebGIS application were complex and multidisciplinary, involving a team of experts from the geological, mining, economic, ecologic, informatics, mathematics and other domains. Special ...

  • A Model for Determining the Dependability of Continuous Subsystems in Coal Mines Using the Fuzzy Logic Approach

    Nikola Stanić, Miljan Gomilanović, Petar Marković, Daniel Krzanović, Aleksandar Doderović, Saša Stepanović (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    fuzzy logic, max-min composition, continuous part of combined system (CCS), open pit, mining, dependability

  • Review: Methodological approaches and research techniques for addressing construction and remediation problems in karst reservoirs

    Saša Milanović, Ljiljana Vasić (2021)
    Earth and Planetary Sciences (miscellaneous), Water Science and Technology

  • 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

  • A methodology for assessing the pressures on transboundary groundwater quantity and quality – experiences from the Dinaric karst

    Zoran Stevanović, Veljko Marinović (2020)
    A relatively novel and abridged methodology for assessing the quantity and quality status of groundwater bodies has been applied in the Dinaric karst of SE Europe. Validation of pressure on quantity is based on groundwater budgeting and the correlation of available groundwater reserves and projected water demands, while pressure on quality is estimated by GIS-created maps: vulnerability – hazard – risk. The results obtained from the studied groundwater bodies indicate mostly low pressure on water quantity, but increased risk from diffuse and point pollution sources. ...
    međugranična izdan, karst, ranjivost, hazard, rizik, Dinaridi

  • 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
    ... vibration levels or pressure that may indicate the pump's condition. b.Polynomial Regression - Used for modeling complex relationships between variables, which can help in predicting complex patterns in pump behavior. • ModelTraining a.Training - The model is trained on labeled data. In this process ...
    ... pair can be treated as a complex number: s(k) = x(k) + jy(k) O) where k=0,1,2,...,N-1, and N represents the number of points on the contour. In this approach, the x-axis is treated as the real axis, while the y-axis is used as the imaginary axis for the sequence of complex numbers. This method has ...
    ... l conditions and sensor faults using machine learning in deep well pumping. This segment explores how machine learning can be used to analyze complex patterns in sensor data and identify issues in pump operation or sensor faults. Proactive management of pump performance and prevention of downtime ...

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management ...
    ... support, and from the appropriate maintenance assets [2]. Analytic determination of availability function is possible but requires specific, quite complex IT system. Therefore, in this paper, an expert model, that integrates reliability, maintainability, and supportability in the measure of availability ...
    ... selected machine or overall business systems [5]. The most usual consideration of the availability of machines or any other engineering system in a complex manner is by taking into consideration indicators of reliability, maintainability, and supportability [5]. In other words, to provide complete ...

  • History of the development of the hydrodynamic model of the open pit mine “Drmno”, Serbia

    Dušan Polomčić, Jelena Ratković, Vesan Ristić Vakanjac (2023)
    With the creation of a hydrodynamic model, the need for it usually ceases until some next moment when the model needs to be updated and used for the set task for the necessary project documentation or dedicated studies. It is relatively rare that almost every year the model is improved and used for forecast calculations. The paper presents the basic characteristics and development of the hydrodynamic model of the open pit mine “Drmno” for 25 years. This open pit ...
    hydrodynamic model, open pit mine, model recalibration, drainage system

  • Sentiment Analysis of Serbian Old Novels

    Ranka Stanković, Miloš Košprdić, Milica Ikonić Nešić, Tijana Radović (2022)
    In this paper we present first study of Sentiment Analysis (SA) of Serbian novels from the 1840-1920 period. The preparation of sentiment lexicon was based on three existing lexicons: NRC, AFFIN and Bing with additional extensive corrections. The first phase of dataset refinement included filtering the word that are not found in Serbian morphological dictionary and in second automatic POS tagging and lemma were manually corrected. The polarity lexicon was extracted and transformed into ontolex-lemon and published as initial ...
    sentiment lexicon, sentiment analysis, distant-reading, machine learning, old novels