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Упит dcterms_subject_txt:Well Performance Optimization

297 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
    ... publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 7% International Symposium MINING AND ENVIRONMENTAL PROTECTION 25 - 28 September 2019, Vrdnik, Serbia THE OPTIMIZATION OF AUXILIARY MACHINERY IN OPEN-CAST LIGNITE ...
    ... 04:30:52 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 Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] The optimization of auxiliary ...
    ... defines the optimal bulldozer replacement period within the life cycle of that machihe. Keywords: Open-cast coal mine, auxiliary works, bulldozers, optimization, availabilifty. 1. INTRODUCTION Dozers are most common auxiliary machines at open-cast coal mines, both by type and the scope of tasks these ...

  • Optimizacija faznog razvoja Površinskog kopa Ciganuša – Škorac u cilju definisanja dugoročne dinamike eksploatcije

    Dejan Stevanović, Petar Marković, Mirjana Banković, Milan Živković (2022)
    Definisanje dugoročne dinamike razvoja rudarskih radova koja je u potpunosti usaglašena sa strateškim ciljevima Investitora, veoma je zahtevan zadatak, koji vrlo često podrazumeva veliki broj ograničenja. Adekvatno definisana dinamika razvoja rudarskih radova treba da obezbedi dugoročne zahteve u pogledu kapaciteta, kvaliteta i raspodele resursa neophodnih za ispunjavanje strateških ciljeva, koji se po pravilu svode na ostvarenje maksimalnog profita. Uspešno definisanje dinamike eksploatacije (posebno kod metaličnih ležišta) u najvećoj meri zavisi od optimizacije faznog razvoja površinskog kopa, odnosno od pravilnog ...
    dinamika razvoja, faze razvoja, optimizacija kopa, strateški ciljevi, Whittle

  • Faktori uticaja na izbor optimalnog sistema odbrane od podzemnih voda kod površinskih kopova

    Dragoljub Bajić, Dušan Polomčić (2015)
    hydrodynamic model, multi-criteria optimization, openpit mine

  • Approach to operational mine planning: Case study Tamnava West

    Dejan Stevanović, Mirjana Banković, Milica Pešić Georgiadis, Ranka Stanković (2014)
    ... Journal of Coal Geology, vol. 80, pp. 145-156 6 Beretta F, Costa J, Koppe J, Souza V, 2009, Reducing coal quality variability with size optimization of blending piles, Fourth World Conference on Sampling & Blending, The Southern African Institute of Mining and Metallurgy 7 Stevanović ...
    ... criteria of power plant. This paper investigates advantage of proper operational planning on coal quality control process and overall production performance. For better understanding case study is conducted on open pit Tamnava West field. Successful operational mine planning is almost impossible without ...
    ... mine planning of pit production. It’s a part of long term planning, and if done inappropriately can have significant impact on overall pit performance. This is especially true for continuous mining technology where pit benches are usually surfaces (not horizontal planes). Many factors have ...

  • Comparing the performance of different landslide susceptibility models in ROC space

    Marjanović Miloš (2013)

  • Forecasting financial distress of mining companies: Tool for examination of key performance indicators

    Zlatanović Dragan, Bugarin Mile, Milisavljević Vladimir (2016)

  • Diagnostics of Bucket Wheel Excavator Discharge Boom Dynamic Performance and Its Reconstruction

    Brkić Aleksandar, Maneski Taško, Ignjatović Dragan, Jovančić Predrag, Spasojević Brkić Vesna (2014)

  • Prediction of roadheader performance in Serbian underground coal mines

    Duško Đukanović, Nemanja Đokić, Rade Tokalić, Luka Crnogorac, Kemal Gutić (2022)

  • Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines

    Ugljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković (2022)
    This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...
    Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems Engineering

  • INVENTS: A Hybrid Mine Ventilation Planning and Design System

    Lilić Nikola, Stanković Ranka, Obradović Ivan (2013)
    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 ...
    hybrid systems, mine ventilation, expert systems
    ... composed out of a number of integrated software packages, such as ResNet, SimVent and VENTEX (Figure 3). These packages integrate both well known numerical optimization and various artificial intelligence methods which allow for an introduction heuristics into the knowledge base, thus upgrading existing ...
    ... control over parts of the problem-solving process. It also offers suggestions and recommendations to the user for the improvement of the overall performance of the mine ventilation system. Fig. 10. VENTEX main interface panel with estimated values and suggestions for possible corrections 4. CONCLUSION ...
    ... ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Proceedings of International Scientific Conference of FME ...

  • INVENTS: a hybrid system for subsurface ventilation analysis

    Nikola Lilić, Ranka Stanković, Ivan Obradović (2000)
    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 ...
    ... composed out of a number of integrated software packages, such as ResNet, SimVent and VENTEX (Figure 3). These packages integrate both well known numerical optimization and various artificial intelligence methods which allow for an introduction heuristics into the knowledge base, thus upgrading existing ...
    ... control over parts of the problem-solving process. It also offers suggestions and recommendations to the user for the improvement of the overall performance of the mine ventilation system. Fig. 10. VENTEX main interface panel with estimated values and suggestions for possible corrections 4. CONCLUSION ...
    ... ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Proceedings of International Scientific Conference of FME ...

  • Komparativna analiza završnih kontura površinskog kopa Drmno

    Dejan Stevanović, Dragan Ignjatović, Tomislav Šubaranović, Mirjana Banković, Petar Marković (2022)
    Definisanje optimalne završne konture površinskog kopa od suštinskog je značaja za ostvarivanje strateških ciljeva u razvoju rudarskih projekata. Savremeni programski paketi i metode za optimizaciju granica kopa, zasnivaju se na pronalasku završne konture koja obezbeđuje maksimalan profit. U slučaju površinskih kopova uglja, kod kojih osim profita postoji i čitav niz dodatnih kriterijuma i strateških ciljeva, princip optimizacije granica prema profitu, najčešće nije u potpunosti primenjiv. Iz rog razloga za uspešno definisanje granica površinskih kopova, neophodno je sagledati čitavu lepezu ...
    završna kontura, ugalj, komparativna analiza, optimizacija, strateški ciljevi

  • Overwiew of In-Pit Crushing & Conveying Technology in Open Pit Mines

    Ali Nasirinezhad, Dejan Stevanović, Dragan Ignjatović, Petar Marković (2021)
    The conditions under which contemporary surface mining operations is carried out obviously becoming increasingly complex. In such complex conditions, the optimization of haulage systems as the technological phase with the largest share in the total operating costs, is very important from the aspect of achieving profitability of the mining project. In a large number of cases, the application of traditional haulage systems with trucks (as the most dominant type of haulage in open pit mines) does not lead to ...
    In Pit Crushing and Conveying, IPCC, open pit mining, haulage, optimization, costs saving

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management

  • Razvoj integralnog modela za optimizaciju diskontinualnog sistema proizvodnje na površinskim kopovima nemetala

    Miodrag Čelebić (2024)
    Izbor optimalne mehanizacije u diskontinualnom sistemu transporta je jedna od najvažnijih odluka koju treba donijeti prilikom projektovanja površinskih kopova. Pri izboru optimalne mehanizacije, uticaj ima veliki broj faktora, kako prirodnih – geoloških i ekoloških, tako i tehničkih, ekonomskih i socijanih. Neki od njih se mogu izraziti numerički, u određenim mijernim jedinicama, a neki opisno, lingvističkim varijablama, shodno uslovima koji vladaju na rudnim ležištima, a koje karakterišu visok stepen neizvjesnosti i neodređenosti kako prilikom istraživanja, tako i tokom procesa eksploatacije ...
    izbor mehanizacije, tehnologija eksploatacije, diskontinualani sistem, ekspertsko odlučivanje, lingvističke varijable, MCDM, FAHP

  • Part of Speech Tagging for Serbian language using Natural Language Toolkit

    Ranka Stanković, Boro Milovanović (2020)
    Dok se razvijaju složeni algoritmi za NLP (obrada prirodnog jezika), osnovni zadaci kao što je označavanje ostaju veoma važni i još uvek izazovni. NLTK (Natural Language Toolkit) je moćna Python biblioteka za razvoj programa zasnovanih na NLP-u. Pokušavamo da iskoristimo ovu biblioteku za kreiranje PoS (vrsta reči) oznake za savremeni srpski jezik. Jedanaest različitih modela je kreirano korišćenjem NLTK API-ja za označavanje. Najbolji modeli se transformišu sa Brill tagerom da bi se poboljšala tačnost. Obučili smo modele na označenom ...
    obrada prirodnog jezika, mašinsko učenje, neuronske mreže
    ... in performance between various tags. This is probably due to the differences in the tagging practice for the training and evaluation sets. In the process of preparing data, there are multiple tagsets and annotators. This is too many factors for an automated tagger to have the performance near maximum ...
    ... conducted using different NLP tool and the exact same resources, there is an evidence of better AII 1.1.4 performance in PoS tagging a contemporary Serbian language [23]. Their performance on unseen data shows 0.88 precision with Spacy tagger and 0.93 with TreeTagger19 while the best tagger produced ...
    ... is shown in Figure 1. First five categories account to 57% of all tokens. These numbers help us in creating the taggers and interpreting their performance. Fig. 1. Word PoS category cumulative distribution For a complete evaluation of the taggers, we need a data from a different domain ...

  • Machine Learning and Deep Neural Network-Based Lemmatization and Morphosyntactic Tagging for Serbian

    Ranka Stanković, Branislava Šandrih, Cvetana Krstev, Miloš Utvić, Mihailo Škorić (2020)
    The training of new tagger models for Serbian is primarily motivated by the enhancement of the existing tagset with the grammatical category of a gender. The harmonization of resources that were manually annotated within different projects over a long period of time was an important task, enabled by the development of tools that support partial automation. The supporting tools take into account different taggers and tagsets. This paper focuses on TreeTagger and spaCy taggers, and the annotation schema alignment ...
    Part-of-Speech tagging, lemmatization, corpus, evaluation, Serbian, morphological dictionary
    ... Part-of-Speech tagset. The trained models will be used to publish the new version of the Corpus of Contemporary Serbian as well as the Serbian literary corpus. The performance of developed taggers were compared and the impact of training set size was investigated, which resulted in around 98% PoS-tagging ...
    ... taggers, their performance on previously unknown texts reveals that there is room for further improvement. We may conclude that the key to improvement of these tag- ger lies in the improvement of the training set. Addition of new grammatical categories where they are missing, as well as locating and ...
    ... represent texts previously un- known to the taggers and show their performance in real world scenario. Figure 1 compares performance of taggers for PoS task against different test sets. While the spaCy tagger shows overall top performance on the Test set, TreeTagger shows better results when tagging ...

  • Upravljanje proizvodnjom nafte – novi alat na bazi fazi logike

    Мирослав Црногорац, Душан Даниловић, Лола Томић (2020)
    ... topology optimization study of support using SOLIDWORKS software. Accent of study is placed on description of topology optimization of support, in other words, mass reduction with equally Von Misses stress distribution taking into account type of material, permissible load capacity as well as constraints ...
    ... constraints. Optimization is conducted within Topology Study module with mass reduction of 39.8[%], compared to the initial design. In addition, future directions of research are given, as well as potential opportunities for additional reduction while the optimal solution is made with additive technology ...
    ... factors that affect the optimization from several aspects. The idea of this paper is to show the advantage of modern systems on the example of large - scale production, the importance of the preparation of production for the total time and production costs. Keywords: Optimization, CNC, milling machine ...

  • Hydrodynamic analysis of radial collector well ageing at Belgrade well field

    Đorđije Božović, Dušan Polomčić, Dragoljub Bajić, Jelena Ratković (2019)
    The origin and effect of hydraulic resistances on the rate of ageing of radial collector wells are identified through numerical hydrodynamic analysis. The research includes hydrodynamic modeling of one such well with new laterals at Belgrade well field. The performance of the laterals is aggravated by rapid ageing. The change in the hydraulic parameters of the laterals during the first decade of operation is analyzed through simulations of the groundwater regime with realistically specified geometries and hydraulics of the ...
    Colmation, Incrustation, Groundwater modeling, MODFLOW–USG, Connected Linear Network Process

  • Assessing Criteria Weights by the Symmetry Point of Criterion (Novel SPC Method) - Application in the Efficiency Evaluation of the Mineral Deposit Multi-Criteria Partitioning Algorithm

    Zoran Gligorić, Miloš Gligorić, Igor Miljanović, Suzana Lutovac, Aleksandar Milutinović (2023)
    Information about the relative importance of each criterion or the weights of criteria can have a significant influence on the ultimate rank of alternatives. Accordingly, assessing the weights of criteria is a very important task in solving multi-criteria decision-making problems. Three methods are commonly used for assessing the weights of criteria: objective, subjective, and integrated methods. In this study, an objective approach is proposed to assess the weights of criteria, called SPC method (Symmetry Point of Criterion). This point ...
    Вишекритеријумско одлучивање, тежине критеријума, тачка симетрије критеријума, налазиште минерала, алгоритам, процена учинка