Вимірювальна техніка та метрологія. – 2021. – Випуск 82, №2

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Measuring Equipment and Metrology : scientific journal. – Lviv : Lviv Politechnic Publishing House, 2021. – Volume 82, № 2. – 58 р.

Вимірювальна техніка та метрологія

Зміст (том 82, № 2)


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Content (Vol. 82, No 2)


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    Dielectric dissipation factor in three-core power cables
    (Видавництво Львівської політехніки, 2021-02-23) Kostiukov, Ivan; National Technical University “Kharkiv Polytechnic Institute”
    This article is devoted to the analysis of components of variance of the results of measurements of dielectric dissipation factor of insulation layers between the conductive elements of the construction of three core power cables with paper impregnated insulation in a common sheath. The analysis of components of variance was carried out by applying presented relations for the direct calculation of the dielectric dissipation factor. The accuracy of presented relations for the calculation of variance components was verified. The results of carried out analysis have shown that the variance of the dielectric dissipation factor measurements is mostly determined by the variances of multiplication of measurements of aggregate values of dielectric dissipation factor and coefficients depending on the partial capacitances of tested three core cable.
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    Material testing and results estimation by safety indexes
    (Видавництво Львівської політехніки, 2021-02-23) Mykyichuk, Mykola; Rudyk, Yuriy; Lviv Polytechnic National University; Lviv State University of Life Safety
    In the article, both the test method features and the test results of research of thermal behavior of steel fragment were analyzed. Two types of test conditions for steel construction material were considered. The definition and main features of measurement techniques were presented. Fire retardant material test results for steel plates with hydrogen combustion shown the limit of fire resistance of the tested samples is more than 30 min. The main advantages and disadvantages of the test were determined. The positive and negative aspects of this approach were analyzed. These techniques' effective thermal condition is in an environment of uncertainty and has no limited resources was established. Concepts and principles for establishing validity, and frameworks and methods for validating test methods and their results are important elements of safety systems. The article considers the safety of the technical component of a complex organizational and technical system with the study of the functional relationship between the safety elements parameters: temperature, time, fire retardant – by hydrogen participation.
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    Problem of the cosmic gravity measurement
    (Видавництво Львівської політехніки, 2021-02-23) Tchaban, Vasil; Lviv Polytechnic National University
    Based on Newton's adapted law of universal gravitation in the case of moving masses, taking into account the finite velocity of gravity, differential equations of motion of celestial bodies are obtained. The transient process of the precession of the planet's perihelion was simulated for the first time. A new physical interpretation of the celestial phenomenon due to the discovered new component of force in addition to the Newtonian and Lorentz (gravitomagnetic) is given. The problem of measuring a new force has been formed. The results of computer simulation of the precessing perihelion of the planet considering a new force component are discussed.
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    Radio frequency identification in cyber-physical systems
    (Видавництво Львівської політехніки, 2021-02-23) Mašková, Kamila; Petrovska, Iryna; Ryshkovskyy, Oleksander; Yatsyshyn, Svyatoslav; Lviv Polytechnic National University
    Automated systems that are part of cyber-physical systems provide distribution of goods or prefabricated components, as well as their documenting and automatic tracking in real-time. Workpieces are marked with RFID transponders. RFID antennas allow contactless reading and/or recording of information, RFID electronics process and transmit it to the programmable logic controller via PROFIBUS DP, PROFINET, Ethernet IP, Ethernet TCP/IP, or EtherCAT interface. The peculiarities of the universal interface for the needs of cyber-physical systems equipped with RFID means and the main metrological characteristics of the latter are studied in the work.
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    Multipurpose measurement models for adjustment by the least-squares method
    (Видавництво Львівської політехніки, 2021-02-23) Kuzmenko, Iuriy; Samoilenko, Olexandr; Tsiporenko, Serhiy; State Enterprise “Ukrmetrteststandard”
    The development of multipurpose measurement models is the precondition for software development for simultaneous adjustment of the large scope and complicated combinations of the measurement results by the least-squares method. Multipurpose measurement models for software can be a helpful tool for processing the final measurement results provided by different measurement methods applying the mentioned software; processing the measurement results of measurement standards comparisons, interlaboratory comparison, and calibration procedures; estimating the additive and multiplicative systematic components of measurement errors and their uncertainty; processing complicated combinations by binding or linking up of the interlaboratory comparison and calibration results in the time; simultaneous processing of the measurement results obtained by various methods e.g. by the method of direct measurements and comparisons; fast-changing the multipurpose measurement models from linear to non-linear type. Processing of the results by software based on the multipurpose measurement model algorithm can help to established a comprehensive measurement traceability network by pooling the single traceability chains.
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    Research of thermometric material Er1-xscxNiSb. I. Modelling of performances
    (Видавництво Львівської політехніки, 2021-02-23) Krayovskyy, Volodymyr; Pashkevych, Volodymyr; Horpenuk, Andriy; Romaka, Volodymyr; Stadnyk, Yuriy; Romaka, Lyubov; Horyn, Andriy; Romaka, Vitaliy; Lviv Polytechnic National University; Ivan Franko National University of Lviv; Leibniz Institute for Solid State Research
    Automated The results of modeling performances of the semiconductor solid solution Er1–xScxNiSb are presented, which can be a promising thermometric material for the manufacture of sensitive elements of thermoelectric and electroresistive thermocouples. Fullprof Suite software was used to model the crystallographic characteristics of the Er1-xScxNiSb thermometric material. Modeling of the electronic structure of Er1–xScxNiSb was performed by Coring-Kon-Rostocker methods in the approximation of coherent potential and local density using the exchange-correlation potential Moruzzi-Janak-Williams and Linear Muffin-Tin Orbital in the framework of DFT density functional theory. The Brillouin zone was divided into 1000 k-points, which were used to model energetic performances by calculating DOS. The width of the energy window was 22 eV and was chosen to capture all semi-core states of p-elements. Full potential (FP) was used in the representation of the linear MT orbital in the representation of plane waves. The accuracy of calculating the position of the Fermi level was εF ± 6 meV. To verify the existence of a continuous solid solution, Er1–xScxNiSb substitution, the change in the values of the period of the unit cell a (x) was calculated within the framework of the DFT density functional theory in the range x = 0–1.0. It is presented that the calculated and experimentally obtained dependences of the period of the unit cell a(x) Er1–xScxNiSb are almost parallel, which confirms the correctness of the used tools and the obtained modeling results. To research the possibility of obtaining thermometric material Er1–xScxNiSb in the form of a continuous solid solution was performed modeling of thermodynamic calculations in the approximation of harmonic oscillations of atoms in the theory of DFT density functional for a hypothetical solid solution Er1–xScxNiSb, x = 0–1.0. It is shown that the change in the values of free energy ΔG(x) (Helmholtz potential) passes through the minimum at the concentration x≈0.1 for all temperatures of possible homogenizing annealing of the samples, indicating the solubility limit of Sc atoms in the structure of the ErNiSb compound. The presence of this minimum indicates that the substitution of Er atoms for Sc atoms in the ErNiSb compound is energetically advantageous only up to the concentration of impurity atoms Sc, x ≈ 0.1. At higher concentrations of Sc atoms, x > 0.10, stratification occurs (spinoidal phase decay). It is shown that modeling of the mixing entropy behavior S even at a hypothetical temperature T = 4000 K shows the absence of complete solubility of Sc atoms in Er1–xScxNiSb. To model the energetic and kinetic performances of the semiconductor thermometric material Er1–xScxNiSb, particularly the behavior of the Fermi level e F , bandgap width e g the distribution of the density of electronic states (DOS) and the behavior of its electrical resistance ρ(x, T) is calculated for an ordered variant of the structure in which the Er atoms in position 4a are replaced by Sc atoms. It is shown that the ErNiSb compound is a semiconductor of the electronic conductivity type, in which the Fermi level is located near the level of the conduction band e C . The modeling showed that at higher concentrations of Sc atoms, the number of generated acceptors exceeds the concentration of uncontrolled donors, and the concentration of free holes exceeds the concentration of electrons. Under these conditions, the Fermi level e F approaches, and then the level of the valence band Er1–xScxNiSb crosses: the dielectric-metal conductivity transition occurs. The experiment should change the sign of the thermo- EMF coefficient α(x, T) Er1–xScxNiSb from negative to positive, and the intersection of the Fermi level e F and the valence band changes the conductivity from activating to metallic: on the dependences ln(ρ(1/T)) the activation sites disappear, and the values of resistivity ρ increase with temperature.
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    Metrological requirements of weigh-in-motion systems for vehicles
    (Видавництво Львівської політехніки, 2021-02-23) Mykyichuk, Mykola; Hut, Taras; Lazarenko, Nadia; Lviv Polytechnic National University
    The article analyzes and proposes solutions for metrological support of weight information systems of road vehicles in motion, including the method of classification of WIM systems by purpose and accuracy classes, metrological requirements for them and control methods for testing and verification, as well as the main metrological risks for Weigh-in-motion systems for road vehicles and requirements for determining and calculating reliability.
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    Parallelization of RSA cryptographic algorithm based on CUDA technologies
    (Видавництво Львівської політехніки, 2021-02-23) Mochurad, Lesia; Kryvenchuk, Yuriy; Yatsyshyn, Svyatoslav; Lviv Polytechnic National University
    The paper examines the efficiency of the application of CUDA technologies for the parallelization of the cryptographic algorithm with the public key. The speed of execution of several implementations of the algorithm is compared: sequential implementation on the CPU and two parallel implementations – on the CPU and GPU. A description of the public key algorithm is presented, as well as properties that allow it to be parallelized. The advantages and disadvantages of parallel implementations are analyzed. It is shown that each of them can be suitable for different scenarios. The software was developed and several numerical experiments were performed. The reliability of the obtained results of encryption and decryption is confirmed. To eliminate the influence of external factors at the time of execution the algorithm was tested ten times in a row and the average value was calculated. Acceleration coefficients for message encryption and decryption algorithms were estimated based on OpenMP and CUDA technology. The proposed approach focuses on the possibility of further optimization through the prospects of developing a multi-core architecture of computer systems and graphic processors.
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    Зміст до “Вимірювальна техніка та метрологія”
    (Видавництво Львівської політехніки, 2021-02-23)
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    Титульний аркуш до “Вимірювальна техніка та метрологія”
    (Видавництво Львівської політехніки, 2021-02-23)