Претрага

Упит dcterms_subject_txt:key block theory

272 items

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja

    Seyed Ali S. Razeghi (2022)
    Gubitak isplake predstavlja nekontrolisano isticanje bušaćeg fluida kroz formacije kao što su kaverne, pukotine, ili drugi slojevi. Tradicionalne metode procene gubitka isplake se zasnivaju na primeni seizmičkih podataka ili pronalasku „mesta“ gubitka isplake na osnovu raspoloživih podataka iz susednih bušotina. Međutim, ove metode procene nisu pouzdane.‘ U disertaciji je izvršena analiza i procena uticaja parametara bušenja, geoloških faktora, karakteristika formacije i fluida na gubitak isplake kao i na formiranje fraktura u formacijama. Uspostavljeni su modeli koji podrazumevaju proces obrade ...
    naftna bušotina, gubitak isplake, fuzzy logika, ANFIS model

  • Pregled hidrodinamičkih istraživanja bunara sa horizontalnim drenovima numeričkim metodama

    Đorđije Božović, Dušan Polomčić, Dragoljub Bajić (2020)
    U radu je predstavljen pregled odabranih hidrodinamičkih istraživanja realizovanih primenom numeričkih metoda simulacije kretanja podzemnih voda pod uticajem rada bunara sa horizontalnim drenovima. Na osnovu pristupa u matematičkom i hidrauličkom tretiranju, kao i numeričkoj simulaciji bunara sa horizontalnim drenovima na modelima, predstavljeni su najznačajniji aspekti izrade hidrodinamičkih modela ovog kompleksnog tipa vodozahvatnog objekta. Metodologija obuhvata izbor: a) graničnih uslova za simulaciju prirodnih granica, izvora prihranjivanja i dreniranja izdani; b) primenjivanog stepena diskretizacije prostora obuhvaćenog modelom u planu i profilu; ...
    horizontalni bunari, hidraulika bunara, analitički modeli, numerički modeli, hidrodinamičko modeliranje podzemnih voda

  • Стратешко планирање функционалности подземних просторија моделом прогнозе деформација

    Лука Црногорац (2023)
    Релативно велике деформације подградне конструкције у подземним рудницима угља у Републици Србији представљају један од главних проблема за постизање планиране производње угља. Деформације подграде су директна последица статичких и динамичких оптерећења стенске масе и у многоме зависе и од времена трајања изложености подграде утицају подземног притиска. Код ниско механизованог радног процеса долази до повећаног излагања подземних просторија утицају подземног притиска услед дугог производног циклуса који је често пропраћен застојима у раду. Веома често подземне просторије се санирају и по ...
    подземне просторије, подграда, прогноза деформација, стратешко планирање

  • Threshold-induced correlations in the Random Field Ising Model

    Sanja Janićević, Dragutin Jovković, Lasse Laurson, Đorđe Spasojević (2018)
    Multidisciplinary
    ... requirements, all collapse onto a sin- gle curve. As the proposed general scaling theory predicts, we anticipate that the derived scaling forms of the threshold induced correlations, provided that the requirements of the theory are ful�lled, should hold for any response signal originating from system that ...
    ... requirements, all collapse onto a sin- gle curve. As the proposed general scaling theory predicts, we anticipate that the derived scaling forms of the threshold induced correlations, provided that the requirements of the theory are fulfilled, should hold for any response signal originating from system that ...
    ... case, the model has a disorder induced transition®-!° in dimensions 2 < d < 6, while for dimensions d > 6 it is described in terms of the mean field theory'"“*. In this model, when the external magnetic field slowly changes, the system relaxes in spin-flipping avalanches, causing abrupt and jerky jumps ...

  • 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
    ... didactic criteria [15]:  adjusting the content to the target group,  systematization and gradualism in the teaching process,  connecting the theory and the practice. To satisfy the first criterion of adjusting the content to the target group, we provided a description of the course, a ...
    ... principles are used to satisfy the criteria of systematization and gradualism in the teaching process. The third principle of connecting the theory and practice is fulfilled by using the video tutorials. These tutorials are designed to present practical use of processes described in theoretical ...
    ... video materials by adding subtitles in other languages. We also plan to add more courses in CL and NLP at the edeX BAEKTEL platform (Basics of Theory of Formal Languages, Information Retrieval, etc.). LITERATURE [1] Carlucci, D., et al., A platform for management of academic and entre ...

  • Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia

    Filip Arnaut, Dragana Đurić, Uroš Đurić, Mileva Samardžić-Petrović, Igor Peshevski (2024)
    General Earth and Planetary Sciences
    ... distinct result as it involves @ Springer KU- Kopaonik Unit (Kopaonik Block and Ridge Unit), EVZ- East Vardar Zone, JU- Jadar Unit, SMM- Serbo-Macedonian Massif, RM- Rhodope Massif, GU- Getic Units, PB- Pannonian Block transforming the original data into data sets for specific pur- poses ...
    ... Syst Sci 13:2815—2831. https://doi.org/10.5194/nhess-13-2815-2013 Cover T, Hart P (1967) Nearest neighbor pattern classification. IEEE Trans Inf Theory 13:21—27. https://doi.org/10.1109/tit.1967. 1053964 @ Springer Earth Science Informatics (2024) 17:1625–1644 Cracknell MJ, Reading AM (2014) ...
    ... Conf on Data Mining, Maebashi City, Japan 641:644 Kanevski M, Pozdnukhov A, Timonin V (2009) Machine Learning for Spatial Environmental Data: Theory. CRC Press, Boca Raton, USA, Applications and Software Karajovanovik M, Hadži-Mitrova S, (1975): Basic geologic map of Former Yugoslavia 1:100 ...

  • Prognoza operativne efikasnosti aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema

    Svetlana M. Štrbac-Savić (2016-06-10)
    Efikasnost predstavlja preduslov za opstanak svake rudarske kompanije, posebno u uslovima izuzetno konkurentnog trţišnog okruţenja kao što je to rudarska industrija. Efikasnost oznaĉava sposobnost kompanije da ispuni svoje kratkoroĉne ili dugoroĉne ciljeve. Operativna efikasnost se definiše kao odnos izmeĊu ulaznih parametara potrebnih za odvijanje proizvodnje i pokazatelja dobijenih proizvodnjom. U kontekstu rudarskog poslovanja, operativna efikasnost se odnosi na vreme potrebno da se mineralno dobro transformiše u novĉana sredstva. Visoka operativna efikasnost se postiţe kada se ostvari prava kombinacija karakteristika ...
    podzemni rudnik, operativna efikasnost, prognoza, teorija sivih sistema, stohastiĉke diferencijalne jednaĉine, simulacija
    ... e, which results in the average or expected value of DOL for every year of defined time horizon. Key words: underground mine, operational efficiency, forecast, grey system theory, stochastic differential equations, simulation Scientific area: Mining engineering Narrow scientific ...
    ... aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema;Operational efficiency forecasting model of an existing underground mine using grey system theory Svetlana M. Štrbac-Savić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Prognoza operativne efikasnosti ...
    ... aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema;Operational efficiency forecasting model of an existing underground mine using grey system theory | Svetlana M. Štrbac-Savić | Универзитет у Београду | 2016-06-10 | | http://dr.rgf.bg.ac.rs/s/repo/item/0004049 Дигитални репозиторијум Рударско ...

  • LRMI markup of OER content within the BAEKTEL project

    Ranka Stanković, Daniela Carlucci, Olivera Kitanović, Nikola Vulović, Bojan Zlatić (2015)
    ... component parts of the course. In the collection of retrieved data related to the blocks are: id of block, type (html, problem, video, discussions ...) and the collection of sub-blocks, the name of the block Open edX Platform REST APIs is used for annotation of course static pages with microdata ...
    ... In section 3 a review of semantic annotation implementation with examples of resource tagging is given. Section 4 of this paper outlines the key aspects of the LRMI standard for describing educational resources, including metadata schema and implementation of LRMI metadata. In section 5 ...
    ... search engines crawl the Web of Data by following links between data sources and provide expressive query capabilities over aggregated data. The key idea of the OER movement is that open educational content should be maximally shared. In [10] authors have shown that interoperability is an important ...

  • Coal homogenization stockyard sizing “Tamnava – Zapad” case study

    Božo Kolonja, Dinko Knežević, Ranka Stanković, Dejan Stevanović, Detlef Trummer (2016)
    ... methods. (Pavloudakis & Agioutantis, 2001) For "Tamnava Zapodno-Polje" a simulation was run on a small test site using data from the technological block model, as well as simulated data based on statistical parameters: average value and standard deviation. It should be pointed out that increasing the ...
    ... pile will take a shorter amount of time, and conversely, a longer pile takes longer to fill. Of course, planning pit operations as a function of block quality at the deposit can resolve this practical problem. Thus from the aspect of stockpiling, the size of the pile depends on the stacking capacity ...

  • Палеогеографска реконструкција јадарског блокатоком млађег палеозоика

    Весна Цветков (2018)
    ... Jugoslavije. Geoinstitut i Barex, Beograd, 82-95 FILIPOVIĆ, I. (2005): Spatial distribution of geological resources in northwestern Serbia (Jadar block terrane) and its relation to tectonic structures. Annales geologiques de la Peninsule balkanique, 66, 17- 20 KARAMATA, S., OLUJIĆ, J., PROTIĆ, LЈ ...

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... for hard and compact soils by measuring the penetration resistance of the bucket knife or tooth in the laboratory on the drilling core samples or block-shaped rock material samples. Consequently, the testing method is most used for determination of the cutting resistance of the material to be excavated ...
    ... seams of surface mines. Nevertheless, the cutting resistance can only be determined by laboratory tests carried out on the drilling core samples or block-shaped rock material samples. The results of laboratory testing allow comparison with test results of rock samples from other mines in which bucket-wheel ...
    ... and their values are σ1 = σ2 = σ3 = P = 250–600 kPa. The cutting resistance testing program is carried out on the core samples (triaxial tests) and block-shaped rock material samples (modified wedge test method). The results of the laboratory triaxial test allow empirical comparison with the values already ...

  • A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović, Filip Miletić (2023)
    This paper presents a model for determining fuzzy evaluations of partial indicators of the availability of continuous systems at coal open pits using a neuro-fuzzy inference system. The system itself is a combination of fuzzy logic and artificial neural networks. The system availability is divided into partial indicators. By combining the fuzzy logic and artificial neural networks, a model is obtained that has the ability to learn and uses expert judgment for that learning. This paper deals with the ...
    системи, континуални системи експлоатације (роторни багер-транспортер-дробилично постројење), рударство, расположивост, меко рачунарство, фази логика, ANN, ANFIS

  • Frequency and Length of Syllables in Serbian

    Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová (2019)
    Basic analyses of several properties of syllables (the rank-frequency distribution, the distribution of length, and the relation between length and frequency) in Serbian is presented. The syllabification algorithm used combines the maximum onset principle and the sonority hierarchy. Results indicate that syllables behave similarly to words as far as mathematical models are concerned, but values of parameters in models for syllables are quite different from those for words.
    frekvencije slogova, dužina slogova, srpski jezik
    ... -H. (2013). Silbenlängen im Deutschen. Glottotheory 4, 36-44. Blevins, J. (1995). The syllable in the phonological theory. In: Goldsmith, J. (ed.), The Handbook of Phonological Theory: 206-244. Oxford: Blackwell. Browne, W. (1993). Serbo-Croat. In: Comrie, B., Corbett, G.G. (eds.), The Slavonic Languages: ...
    ... functions introduced by Wimmer & Altmann (2005), which is a generalization of many linguistic laws (and thus can be considered to be a linguistic theory). Hence regularities in the syllable behaviour follow the same pattern as other lin- guistic units. However, there are important differences if not ...

  • Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization

    Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić (2016)

  • Effectiveness Analysis of Different Bucket-wheel Excavators

    Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić (2021)
    Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...
    bucket-wheel excavator, open-pit coal mine, mining, multi-criteria decision methods

  • Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian

    Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)
    slogovi, distribucija rang-preciznost, slovenski jezici

  • 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
    ... in the framework of long-term survey and maintenance of monuments (Fitzner and Heinrichs 2002). • By aassessing level of damage of each stone block on the monument, quantity of conservation material needed to carry out necessary conservation-restoration treatment, as well as the costs of ...
    ... are present on the monument facades (loss of stone material, discoloration/deposits, detachment and fissures/ deformations). State of each stone block was documented by taking photographs and noting present categories of weathering forms according to groups, main and individual weathering forms ...
    ... completely destroyed blocks. Mapping of weathering forms Mapping of Dark Gate”s facades and registration of weath- ering forms for each built stone block individually enabled characterization of stone degradation according to the type and intensity. It showed that all five groups of damage cate- ...

  • 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

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

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