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1548 items
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VENTEX: An Expert System for Mine Ventilation Systems Analysis
Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...Ranka Stanković, Nikola Lilić, Ivan Obradović. "VENTEX: An Expert System for Mine Ventilation Systems Analysis" in YU Info '96 Brezovica, Društvo za informacione sisteme i računarske mreže (1996)
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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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Optimizacija vodosnabdevanja podzemnim vodama u Srbiji
Dušan Polomčić, Zoran Stevanović, Petar Dokmanović, Vesna Ristić-Vakanjac, Bojan Hajdin, Saša Milanović, Dragoljub Bajić (2012)Dušan Polomčić, Zoran Stevanović, Petar Dokmanović, Vesna Ristić-Vakanjac, Bojan Hajdin, Saša Milanović, Dragoljub Bajić. "Optimizacija vodosnabdevanja podzemnim vodama u Srbiji" in Zbornik radova XIV srpskog simpozijuma o hidrogeologiji sa međunarodnim učešćem, Zlatibor, 17-20. maj 2012. godine , Beograd : Rudarsko-geološki fakultet (2012)
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The Use of the Omeka Semantic Platform for the Development of the University of Belgrade, Faculty of Mining and Geology Digital Repository
Under the regulations of the Ministry of Education, Science and technological Development, a digital repository based on the Omeka S data storage platform has been developed for the Faculty of Mining and Geology. The platform has been upgraded with the required modular extensions, Solr index and automatic OCR. Furthermore, document indexing and search have been fine-tuned with the aid of e-dictionaries of the Serbian language, which has brought about outstanding results in terms of usage facilitation and overall ...Petar Popović, Mihailo Škorić, Biljana Rujević. "The Use of the Omeka Semantic Platform for the Development of the University of Belgrade, Faculty of Mining and Geology Digital Repository" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2020.20.1_2.9
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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... aaaaa a a aaaaagaaaaoi 29 7. Instance-Based Learning ... naanaaaanaaaaaaaaaaaaaagatoati 29 8. Model-Based Learning ... ana a anaaaaa a aaaaaaaaaakaaaaoi 29 5. SENSORS FOR MONITORING SUBMERSIBLE PUMPS ..........anann.. 30 5.1. Pressure sensor 5.1.1. Operating principle.....aaaaaaaa a aaaaaa ...
... Typical rod pump automation includes instrumentation with load cells and position sensors, a pump shut-off control device, a control panel, and a motor drive, and in some cases, a variable-speed drive. Additionally, a radio for receiving and sending information to/from SCADA (Supervisory Control and Data ...
... were tested for a single scale. An example of applying CWT with only one scale to a normalized dynamometric chart from a well is shown in Figure 6.6. 00 02 04 06 08 10 0 2 40 [J P 100 Figure 6.6. Application of CWT with only one scale to a normalized dynamometric chart from a well. Equations ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
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Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material
Borislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić (2022)Pyrophyllite, with the chemical formula Al2Si4O10(OH)2, is a naturally occurring and abundant van der Waals mineral belonging to the group of phyllosilicates. It is very soft, layered crystal used for sculpting and an excellent electrical and thermal insulator aimed for the operation at high pressure and temperature. Here, for the first time, two-dimensional (2D) pyrophyllite obtained by both mechanical and liquid phase exfoliation is presented and investigated at the nanoscale. The layered structure provides low friction coefficient of around ...Atomic force microscopy, Insulating properties, Nanofriction and wear, Natural two dimensional materials, Phyllosilicates, PyrophylliteBorislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić. "Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material" in Applied Surface Science, Elsevier BV (2022). https://doi.org/10.1016/j.apsusc.2022.155114
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A bilingual digital library for academic and entrepreneurial knowledge management
A generic knowledge management process of organization, storage and retrieval of knowledge can suitably be fitted in a digital library. In the digital and knowledge age digital libraries can be used in knowledge management to handle intellectual assets and support knowledge creation. A multilingual digital library either stores content in more than one language or provides multilingual query access to monolingual content. In Serbia 18 of 308 scientific journals regularly published are bi-lingual, with papers simultaneously being in English ...Ranka Stanković, Cvetana Krstev, Biljana Lazić, Dalibor Vorkapić. "A bilingual digital library for academic and entrepreneurial knowledge management" in Proceeding of 10th International Forum on Knowledge Asset Dynamics — IFKAD 2015: Culture, Innovation and Entrepreneurship: connecting the knowledge dots, Bari, Italy, 10-12 June 2015, Bari : IFKAD (2015)
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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
... structural cffect, where a structure/component of the drive assembly acts as a signal amplifier at a sensitive frequency, or a frequency that cannot be characterized as a diagnostic parameter. To prove a negative impact, primarily that of a worn rear support of the electromotor mount (increased ...
... 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 highly-complex dynamic system with a large number of vibration sources. It is sufficiently elastic and features different degrees ...
... electromotor of a bucket wheel excavator as a result of intensified wear-and-tear of its mount support Vesna Damnjanović!, Predrag Jovančić?, Snežana Aleksandrovićž University of Belgrade – Faculty of Mining and Geology, Belgrade, Serbia ?2Corresponding author E-mail: !vesna.damnjanovic(a\rgf.bg.ac ...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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Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers
This paper presents a dynamic California Bearing Ratio (CBRd) device that can be used on a prepared pavement foundation layer to obtain a certain parameter of the tested material in the laboratory and in situ in a direct and fast way. For the selected natural material (gravel), it is shown that the laboratory CBRd can be used to estimate the compaction and bearing capacity, because it correlates well with the parameters of the standard and modifed Proctor compaction tests. ...korelacija parametara, donji slojevi saobraćajnica, laboratorijska i terenska ispitivanja, dinamički kalifornijski indeks nosivosti CBRd... a % - b 200 - ii D tl/(:· AŠ |=} 180 - 70 //E?] “ (-P-4"| AAJA N B D/_T'Jč, ___160 – A “A Ee . PrO M “ A Š Š D n f Č ĆA A -- o B 140 ; _ [- Ž . A a 50 M ~ : AAA AA n 070 - BI A AAAA %Ž mpon-- D A Z AA _ |j A 0 7 O A ŠA -& W m 1 l 100 _Z A a A |} A 30 80 ii CBRa(%) a E iii ...
... performed on a subgrade layer made of natural stone aggregate (gravel). The subgrade layer was constructed above the embankment layer, which consist- ed of natural material (sand) in three layers with a thickness of 0.3 m. Spreading was performed in a layer with a thickness of 0.35 m under a loose condition ...
... Email: milan.bogdanovic(Ottpaqi.com. This paper presents a dynamic California Bearing Ratio (CBR,) device that can be usedon a prepared pavement foundation layer to obtain a certain parameter of the tested material in the laboratory and in situ in a direct and fast way. For the selected natural material ...Milan Bogdanović, Snežana Bogdanović, Dragoslav Rakić, Irena Basarić Ikodinović. "Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers" in Soil Mechanics and Foundation Engineering, Springer Science and Business Media LLC (2024). https://doi.org/10.1007/s11204-024-09939-x
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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... 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 ...
... Stankov In [9] Vieira, extending a result of Lakatos and Losonczi [3], presented a sufficient condition for a self-reciprocal polynomial to have a fixed number of roots on the complex unit circle U = {z ∈ C : |z| = 1}. Let p(z) = adzd +ad−1zd−1 + · · ·+a1z +a0 be a d-th degree self-reciprocal polynomial ...
... 2l roots on U and these roots are simple. Here we present, in a sense, a result which lies in the opposite direction of a special case of this theorem. Namely, we shall prove the following Theorem 1.1. A real algebraic integer τ > 1 is a Salem number if and only if its minimal polynomial P (x) is ...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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A Data Driven Approach for Raw Material Terminology
Olivera Kitanović, Ranka Stanković, Aleksandra Tomašević, Mihailo Škorić, Ivan Babić, Ljiljana Kolonja (2021)The research presented in this paper aims at creating a bilingual (sr-en), easily searchable, hypertext, born-digital, corpus-based terminological database of raw material terminology for dictionary production. The approach is based on linking dictionaries related to the raw material domain, both digitally born and printed, into a lexicon structure, aligning terminology from different dictionaries as much as possible. This paper presents the main features of this approach, data used for compilation of the terminological database, the procedure by which it has ...sirovine, rudarstvo, terminologija, rečnik, terminološka aplikacija, mobilna aplikacija, digitizacija, leksički podaci, korpusi, otvoreni povezani podaciOlivera Kitanović, Ranka Stanković, Aleksandra Tomašević, Mihailo Škorić, Ivan Babić, Ljiljana Kolonja. "A Data Driven Approach for Raw Material Terminology" in Applied Sciences, MDPI AG (2021). https://doi.org/10.3390/app11072892
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Resource-based WordNet Augmentation and Enrichment
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 ...Ranka Stanković, Miljana Mladenović, Ivan Obradović, Marko Vitas, Cvetana Krstev. "Resource-based WordNet Augmentation and Enrichment" in Proceedings of the Third International Conference Computational Linguistics in Bulgaria (CLIB 2018), May 27-29, 2018, Sofia, Bulgaria, Sofia : The Institute for Bulgarian Language Prof. Lyubomir Andreychin, Bulgarian Academy of Sciences (2018)
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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.Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová. "Frequency and Length of Syllables in Serbian" in Glottometrics (2019)
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3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia
Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeSaša Milanović, Zoran Stevanović, Ljiljana Vasić, Vesna Ristić-Vakanjac. "3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia" in Environmental Earth Sciences, Springer Science and Business Media LLC (2013). https://doi.org/10.1007/s12665-013-2591-9
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Bilingual lexical extraction based on word alignment for improving corpus search
Jelena Andonovski, Branislava Šandrih, Olivera Kitanović. "Bilingual lexical extraction based on word alignment for improving corpus search" in The Electronic Library, Emerald (2019). https://doi.org/10.1108/EL-03-2019-0056
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A survey of greenhouse gases production in central European lignites
Anna Pytlak, Anna Szafranek-Nakonieczna, Weronika Goraj, Izabela Śnieżyńska, Aleksandra Krążała, Artur Banach, Ivica Ristović, Mirosław Słowakiewicz, Zofia Stępniewska (2021)Anna Pytlak, Anna Szafranek-Nakonieczna, Weronika Goraj, Izabela Śnieżyńska, Aleksandra Krążała, Artur Banach, Ivica Ristović, Mirosław Słowakiewicz, Zofia Stępniewska. "A survey of greenhouse gases production in central European lignites" in Science of The Total Environment, Elsevier (2021). https://doi.org/10.1016/j.scitotenv.2021.149551
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A Mathematical Learning Environment Based on Serbian Language Resources
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 ...Radojičić Marija, Obradović Ivan, Stanković Ranka, Utvić Miloć, Kaplar Sebastijan. "A Mathematical Learning Environment Based on Serbian Language Resources" in Proceedings of the 7th International Scientific Conference Technics and Informatics in Education, Faculty of Technical Sciences, Čačak (2018)
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Laboratory Testing of Nanosilica- Reinforced Silicate and Polyacrylamide Gels
Irina Zahirovic, Dušan Danilović, Milica Šuput Vranjin, Miloš Tripković. "Laboratory Testing of Nanosilica- Reinforced Silicate and Polyacrylamide Gels" in SPE Journal (2023)
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The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines
In this paper we present how resources and tools developed within the Human Language Technology Group at the University of Belgrade can be used for tuning queries before submitting them to a web search engine. We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic ...LR web services, MultiWord Expressions & Collocations, Information Extraction, Information RetrievalKrstev Cvetana, Stanković Ranka, Vitas Duško, Obradović Ivan. "The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines" in LREC 2008: Conference on Language Resources and Evaluation, Marrakesh, Morocco, May 2008, European Language Resources Association (ELRA) (2008)
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Two approaches to compilation of bilingual multi-word terminology lists from lexical resources
In this paper, we present two approaches and the implemented system for bilingual terminology extraction that rely on an aligned bilingual domain corpus, a terminology extractor for a target language, and a tool for chunk alignment. The two approaches differ in the way terminology for the source language is obtained: the first relies on an existing domain terminology lexicon, while the second one uses a term extraction tool. For both approaches, four experiments were performed with two parameters being ...... mikrofišu ‘title field on a microfiche’ or A_N_(A_N)gen in poslednja sveska serijske publikacije ‘last issue of the serial publication’ where A stands for an adjective, N for a noun and PREP for a preposition. Each of these components can be a single word or a MWU. Our system was used in a mode in which all ...
... bilingual, aligned, domain-specific textual resources, a terminological list and/or a term extraction tool in a source language, and a system for the extraction of terminology-specific noun phrases (MWTs) in a target language, it is possible to compile a bilingual aligned terminological list. This paper ...
... were observed in order to build a discrimina- tive model for the bilingual lexicon induction. Hazem and Morin (2016) The authors built two vector space models: a domain model and a gen- eral model (using a general purpose dictionary). If a domain term exists in a general model, its vector representation ...Branislava Šandrih, Cvetana Krstev, Ranka Stanković. "Two approaches to compilation of bilingual multi-word terminology lists from lexical resources" in Natural Language Engineering, Cambridge University Press (CUP) (2020). https://doi.org/10.1017/S1351324919000615