Приказано Природно-математички факултет за наслов

Приказ резултата 139-158 од 269

    • Mathematical Approach for System Repair Rate Analysis Used in Maintenance Decision Making 

      Kontrec, Nataša; Panić, Stefan; Panić, Biljana; Marković, Aleksandar; Stošović, Dejan (MDPI, 2021-05-20)
      Reliability, the number of spare parts and repair time have a great impact on system availability. In this paper, we observed a repairable system comprised of several components. The aim was to determine the repair rate ...

    • Mathematical Modeling of Integral Characteristics of Repair Process under Maintenance Contracts 

      Kontrec, Nataša; Vujaković, Jelena; Tošić, Marina; Panić, Stefan; Panić, Biljana (MDPI, 2021-12-08)
      The repair rate is a very important parameter for system maintainability and can be defined as a frequency of successfully performed repair actions on a failed component per unit of time. This paper analyzes the integral ...

    • MAXIMUM RELIABILITY K-CENTER LOCATION PROBLEM 

      Kontrec, Nataša; Panić, Biljana; Tošić, Marina; Vujošević, Mirko (Union of Mathematicians of Macedonia - ARMAGANKA, 2020-10-31)
      This paper presents an approach for solving the maximum reliability k-center location problem. We are modifying the well-known p-center problem in order to determine the location of the observed objects and maximize the ...

    • Method for investigation of mode coupling in multimode step-index silica photonic crystal fibers 

      Savović, Svetislav; Kovačević, Milan; Simović, Ana; Kuzmanović, Ljubica; Drljača, Branko; Djordjevich, Alexandar (Elsevier, 2021-07-30)
      We propose a new method for investigation the state of mode coupling in a multimode step-index silica photonic crystal fiber (SI SPCF) with a solid-core by solving the time-independent power flow equation. For various ...

    • A mini review of electroanalitical methods for pesticides quantification 

      Jevtić, Sonja; Stanković, Dalibor; Jokić, Anja; Petković, Branka
      This review paper shows the progress made in the last five years in electrochemical methods applied for the purpose of detection and quantification of pesticides - nowadays the most serious pollutants of the environment. ...

    • Modeling electrostatic potential in FDSOI MOSFETS: An approach based on homotopy perturbations 

      Kevkić, Tijana S.; Nikolić, Vojkan R.; Stojanović, Vladica S.; Milosavljević, Dragana D.; Jovanović, Slavica J. (De Gruyter, 2022-01-26)
      Modeling of the electrostatic potential for fully depleted (FD) silicon-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOSFET) is presented in this article. The modeling is based on the analytical ...

    • Modeling of power flow in multimode W-type photonic crystal fibers 

      Drljača, Branko; Savović, Svetislav; Kovačević, Milan S.; Simović, Ana; Kuzmanović, Ljubica; Djordjevich, Alexandar; Yussupova, Gulbakhar (МИНИСТЕРСТВО НАУКИ И ВЫСШЕГО ОБРАЗОВАНИЯ РОССИЙСКОЙ ФЕДЕРАЦИИ Некоммерческое акционерное общество «Алматинский университет энергетики и связи имени Гумарбека Даукеева» Федеральное государственное бюджетное образовательное учреждение высшего образования «Казанский государственный энергетический университет», 2023-01-01)
      In this paper recent advances in application of power flow equation to Wtype photonic crystal fibers (PCF) is presented. As known for many years power flow equation has been proven to be best solution when transmission ...

    • MODERN TEACHING TECHNOLOGIES AND DEVELOPING CONSTRUCTIVE THINKING 

      Mihajlov Carević, Miroslava; Petrović, Milena; Denić, Nebojša (4th International Scientific Conference – EMAN 2020 – Economics and Management: How to Cope With Disrupted Times, Online/Virtual, September 3, 2020, SELECTED PAPERS published by: Association of Economists and Managers of the Balkans, Belgrade, Serbia, 2020-09-03)
      Numerous researches in the previous period have shown the effectiveness of mathematical learning with the use of information and communication technologies (ICT) and mathematical software packages. Also, through theoretical ...

    • Morfološka i elektrohemijska karakterizacija nanočestica srebra i gvožđe-oksida namenjenih za elektroanalizu 

      Pantović, Tijana; Jovanović, Filip; Petković, Branka; Laban, Bojana
      Nanočestice metala i oksida metala (NPs) privlače pažnju mnogih istraživača zbog svojih jedinstvenih optičkih i električnih svojstva. Ove nanočestice nalaze primenu u biologiji, medicini, kao i u elektronici, za izradu ...

    • Mosses as bioindicators of radionuclide and metal pollution in northern Kosovo and Metohija mountain region 

      Gulan, Ljiljana; Jakšić, Tatjana; Milenkovic, Biljana; Stajic, Jelena M.; Vasić, Predrag; Simić, Zoran
      The study investigates mosses (Hypnum cupressiforme Hedw.) as bioindicators of pollution in three non-urban mountain areas of northern Kosovo and Metohija regions. Concentrations of radionuclides and metals were measured ...

    • Nano-Fe2O3 particles as voltammetric signal amplifiers in sensing of heavy metals and pesticides 

      Milenković, Mila; Jevtić, Sonja; Laban, Bojana; Petković, Branka; Jokić, Anja
      Nanočestice na bazi oksida gvožđa (NPs) su privukle veliku pažnju imajući u vidu njihove fizičke, posebno magnetne, i hemijske osobine. U ovom istraživanju su nanočestice gvožđe(III)-oksida (Fe2O3 NPs) sintetisane jednostavnim ...

    • Nano-silica-based urea-formaldehide composite with some derivates of coumarin as formaldehyde scavenger: hydrolitycal and thermal stability 

      Jovanović, Vojislav; Samaržija-Jovanović, Suzana; Petković, Branka; Jovanović, Slaviša; Marković, Gordana; Porobić, Slavica; Marinović-Cincović, Milena (Springer Nature, 2021-01-25)
      The hydrolytic stability of two nano-SiO2-based UF composites with derivates of coumarin (names as K-1 and K-2) was investigated. K-1 is 3-nitro-4-(p-tolylamino)-2H-chromen-2-one and K-2: 4-((3-nitro-2-oxo-2H-chromen-4-y ...

    • Nanospectroscopy of thiacyanine dye molecules adsorbed on silvernanoparticle clusters 

      Ralević, Uroš; Isić, Goran; Vasić-Anićijević, Dragana; Laban, Bojana; Bogdanović, Una; Lazović, Vladimir; Vodnik, Vesna; Gajić, Radoš (Elsevier, 2017-10-25)
      The adsorption of thiacyanine dye molecules on citrate-stabilized silver nanoparticle clusters drop-cast onto freshly cleaved mica or highly oriented pyrolytic graphite surfaces is examined using colocalized surface-enhanced ...

    • Neodrživost prakse urbanističkog planiranja u Srbiji – primer izmena i dopuna planova generalne regulacije. 

      Ristić, Dušan; Ivanović, Marko; Marjanović, Marjan; Milošević, Dušan; Miličević, Mario (Asocijacija prostornih planera Srbije, Univerzitet u Beogradu – Geografski fakultet, 2018-04-10)
      Srbija nakon 2000. godine, urbzano prolazi kroz proces post-socijalističke transformacije. Ovaj proces prati transformacija socijalističke privrede, odlikovane snažnom regulatornom ulogom države, ka kapitalističkoj privredi, ...

    • A new approach to multivalued nonlinear weakly Picard operators 

      Mukheimer, Aiman; Vujaković, Jelena; Hussain, Azhar; Aydi, Hassen; Radenović, Stojan; Yaqoob, Saman (Springer Nature SharedIt, 2019-11-09)
      The notion of nonlinear (Fs,L)-contractive multivalued operators is initiated and some related fixed point results are considered. We also give an example to show the validity of obtained theoretical results. Our results ...

    • A new longipinane ketone from Achillea abrotanoides (Vis.) Vis.: chemical transformation of the essential oil enables the identification of a minor constituent 

      Radulović, Niko; Mladenović, Marko; Ristić, Milenko; Dekić, Vidoslav; Dekić, Biljana; Ristić, Novica (Wiley-VHCA AG, Zurich, Switzerland, 2019-12-10)
      Introduction: Minor plant constituents are difficult to identify due to the challenging isolation and acquiring of reliable spectral data. Essential oils abound in such minor constituents that might be of high importance ...

    • New natural products from the epicuticular wax of Dianthus cruentus Griseb. (Caryophyllaceae) 

      Radulović, Niko; Ristić, Milenko; Mladenović, Marko; Ristić, Novica; Dekić, Vidoslav; Dekić, Biljana; Ranđelović, Vladimir
      Detailed GC and GC-MS analysis of a diethyl ether washings of fresh flowers of Dianthus cruentus Griseb. (Caryophyllaceae) enabled the identification of 153 constituents. The major identified compounds were long-chain ...

    • New results on F-contractions in complete metric spaces 

      Vujaković, Jelena; Kontrec, Nataša; Tošić, Marina; Fabiano, Nicola; Radenović, Stojan (MDPI (Basel, Switzerland), 2021-12-21)
      The main purpose of this paper is to improve, generalize, unify, extend and enrich the recent results established by Dung and Hang (2015), Piri and Kumam (2014, 2016), and Singh et al. (2018). In our proofs, we only use ...

    • A note on hybridization process applied on transformed double step size model 

      Petrović, Milena; Rakočević, Vladimir; Valjarević, Dragana; Ilić, Dejan (Springer, 2019-12-03)
      We introduce a hybrid gradient model for solving unconstrained optimization problems based on one specific accelerated gradient iteration. Having applied a three term hybridization relation on transformed accelerated double ...

    • Notes on product semi-symmetric connection in a locally decomposable Riemannian space 

      Maksimović, Miroslav; Stanković, Mića
      The purpose of this paper is to investigate the product semisymmetric connection in a locally decomposable Riemannian space. The curvature tensors of this connection were considered. Some properties of almost product ...