Вимірювальна техніка та метрологія. – 2020. – Випуск 81, №4

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Measuring Equipment and Metrology : scientific journal. – Lviv : Lviv Politechnic Publishing House, 2020. – Volume 81, № 4. – 40 р.

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Calibration of the ultrasonic sensor-range finder by the laser interferometer
(Lviv Politechnic Publishing House, 2020) Yatsyshyn Svyatoslav; Nazarkevych Ihor; Mastylo Rostyslav
The accuracy characteristics of the ultrasonic range finder are studied in the work. The latter has been calibrated by a laser interferometer. The problems that arise are described. The calibration method was implemented with the help of a measuring installation, along the rail of which an ultrasonic sensor – range finder and a laser interferometer were fixed. Key words: Sensor; Ultrasonic Rangefinder; Laser interferometer; Measuring installation; Sensor calibration.
Specialized software and hardware for impedance spectroscopy of thermoelectric energy converters
(Lviv Politechnic Publishing House, 2020) Dunets Roman; Dzundza Bogdan; Kostyuk Oksana
The technique of characteristics of thermoelectric energy converters based on the study of the frequency dependence of their impedance is presented. Specialized hardware and software for impedance spectroscopy of thermoelectric modules have been developed. For the analysis of the obtained spectra, an electrothermal model was taken as a basis, which describes the experimental results well and allows one to obtain not only electrical but also thermal characteristics of a thermoelectric energy converter. Key words: Software; Hardware; Impedance Spectroscopy; Laboratory Research; Thermoelectric Converter
Uncertainties of the estimators and parameters of distribution in measurements with multiply observations
(Lviv Politechnic Publishing House, 2020) Dorozhovets Mykhaylo; Szlachta Anna
The article shows that the commonly used method of estimating the Type A uncertainty of measurements based on the standard deviation of estimators of population parameters does not meet the definition of uncertainty. For correct determination of the standard uncertainty, it is necessary to use the distribution of the corresponding population parameter at the values of population estimators determined from the experiment but not the probability distribution of the estimator. The joint probability distribution of population parameters can be derived by transforming the joint distribution of estimators using a Jacobian equal to the ratio of the scale parameter estimator to the population scale parameter itself. Independently on population distribution, the standard uncertainties of the location and scale parameters of the population depend on the number of observation n as a function of 1 3 n - , i.e. can be determined when n ≥ 4. When the number of observations is small then the uncertainty value calculated by the usual method may differ significantly from the correct value. The given numerical example confirms this statement. Key words:Measurement; Observation; Estimator; Uncertainty; Probability distribution.
RSA algorithm elements in ternary affine transformations in encryption-decryption of images
(Lviv Politechnic Publishing House, 2020) Kovalchuk Anatoliy; Lotoshynska Nataliia; Podavalkina Mariia; Pelekh Khrystyna
Regarding image encryption, a crucial task is to implement the application of such an RSA algorithm which will provide an opportunity: – not to decay the cryptographic stability of the RSA algorithm; – to ensure complete noisiness of an image to prevent the application of methods of visual image processing. An algorithm for encryption-decryption of monochrome images using elements of the RSA algorithm as the most resistant to unauthorized signal decryption in ternary affine transformations is proposed. The developed algorithm is applied to images in which there are strictly delineated contours. Elements of the RSA algorithm are proposed to be used to construct the coefficients of ternary affine transformations. The proposed algorithm has higher cryptographic stability compared to the RSA algorithm. The ways of applying the elements of the RSA algorithm in affine transformations in encryption-decryption of images are described in this article. The results of modeling the affine modified cipher for cryptographic transformations of black and white monochrome images of a given dimension are presented. Modified models and algorithmic procedures of key generation processes, direct and inverse cryptographic transformations, which are reduced to matrix element-by-element operations by module, are developed. Key words: Encryption; Monochrome image; Ternary affine transformation; Contour; Decryption.
Mineral waters study with help of admittance spectroscopy
(Lviv Politechnic Publishing House, 2020) Pokhodylo Yevgen; Boyko Volodymyr
The paper proposes a method of identification of mineral waters by components of their immittance. The active and reactive components of the admittances are selected as such components. We received the results of experimental researches on components of admittance of mineral waters of different types in the frequency range of the test signal. Experimental researches were performed on real samples of mineral waters. Analysis of the results showed the following. Among all types of samples, Polyana Kvasova water differs significantly in electrical parameters. It differs from all by the form of the curve (the dependence of the components on the frequency) and much higher absolute values of the components of the admittance. Identification of mineral waters is carried out by comparing the components of the test sample with the corresponding components of the reference sample. This allows you to quickly detect falsification of mineral water. Such identification can be implemented by one measuring instrument and by the same method. Key words: Admittance; Reactive component of admittance; Active component of admittance; Mineral water; Product identification; Standard sample; Impedance spectroscopy.
Trend extrapolation method for qualitative prognosis of the global cybersecurity index in Ukraine
(Lviv Politechnic Publishing House, 2020) Polotai Orest; Lagun Andrii; Kukharska Nataliia; Samotyy Volodymyr
In the paper, the research problem of cybersecurity in Ukraine and constituent elements of the cybersecurity global index were considered. The study object is the methods of predicting the indicator of the cybersecurity global index in Ukraine based on the trend extrapolation methods using one dynamic sequence. The purpose of the work is to apply predicting methods to build a prediction of the global cybersecurity index in Ukraine. The tasks of the job are to build a global cybersecurity index prediction based on average absolute gain, building a prediction of global cybersecurity index based on the average growth rate, building a prediction of global cybersecurity index based on flowing average, assessing the quality of prediction of each method and comparing them with each other to choose the best one. There was selected an indicator to characterize the state of cybersecurity development in Ukraine – the Global Cybersecurity Index, and a feature of using the global cybersecurity indicator and all the components on which it is built and which form it was described. Also, different values for Ukraine’s five-year global cybersecurity index were formed by using official reports generated by the International Telecommunications Union located in Switzerland. Based on data of 2014–2018 years global cybersecurity index projections in Ukraine for 2019 and 2020 years have been developed. The qualitative Global cybersecurity index predicting was considered using the database of simple trend extrapolation methods. This database includes the ollowing methods: a trend extrapolation method based on the average absolute gain, a trend extrapolation method based on the average growth factor, a trend xtrapolation method based on flowing average. Also, the method of ex-post predicating to qualitatively and quantitatively compare the results of each method and determine the best of them was implemented and obtained values and made a diagram of possible future events were compared. The obtained results give reason to hope for improvement of the global cybersecurity index in Ukraine, which maintains the provided existing trends in the development of the cybersecurity sector in the country. Key words: Cybersecurity; Global Cybersecurity Index; Predicting; Trend; Extrapolation.