Abstract: We consider the problem of separation of the total losses in the electric steel of a magnetic circuit into two components: the losses caused by hysteresis and the losses caused by eddy currents. The solution of this technical problem would enable us to guarantee the possibility of efficient design and construction electric machines with magnetic circuits characterized by low magnetic losses. We deduce computational formulas for the hysteresis and eddy-current components of losses, which contain the levels of total losses measured in the open-circuit tests for two different frequencies of magnetization reversal and the ratio of these frequencies. It is shown that the optimal ratio of the frequencies of magnetization reversal is equal to 1.2. We also present the plots of dependences and the expressions aimed at finding the exponent of dependence of the frequency of magnetization reversal on the measured open-circuit losses and the values of frequency. PubDate: 2021-03-02

Abstract: An original method for rapid choice of the spread coefficients of the kernel functions in nonparametric estimates of multidimensional Rosenblatt–Parzen type probability densities is justified. The proposed method makes it possible to substantially increase the computational efficiency of the procedure for optimizing kernel estimates of the probability density for statistical data from a large sample volume compared to the traditional method. The proposed approach is based on analyzing a formula for the optimum parameter of the spread coefficients of a multidimensional kernel estimate for the probability density. Relationships are found between the nonlinear functional of the probability density and its derivatives up to second order, including of the antikurtosis coefficients of random variables. The spread coefficients for each random variable are represented as the product of an undetermined parameter and their mean square deviation. The effect of the error in recovering the established functional dependences on the approximation properties of the kernel estimate of the probability density is determined. These results are implemented in the form of a method for synthesis and analysis of a fast algorithm for choosing the spread coefficients of the kernel estimate of a two-dimensional probability density of independent random variables. The proposed method is implemented using data on the quantitative characteristics of a family of log-normal distribution laws. PubDate: 2021-03-02

Abstract: The present paper discusses the problem of distortions in speech signals transmitted over a communication channel to a biometric system during voice-based remote identification. A possible rectification approach involves a preliminary correction of the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions is proposed, along with a method for its measurement under conditions of small observation samples. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Results of an experimental test of the proposed approach are provided for three different communication channel instantiations. It is shown that the proposed method facilitates the transformation of an initially distorted speech signal into compliance with a registered voice template using an acceptable algorithmic information discrimination criterion. The described approach may be used in existing biometric systems and speaker identification technologies. PubDate: 2021-03-02

Abstract: We solve the problem of increasing the reliability and efficiency of quality control for semiconductor devices and present the analysis of the conditions of measuring the power spectral density of low-frequency noise in semiconductor devices with spectra of the form G(f) ~ f–γ (γ is the parameter of shape of the spectrum) under the conditions of mass quality control. The measurement error of the power spectral density under given conditions of measurements strongly depends on the value of the parameter of form of the spectrum. We propose adaptive algorithms aimed at measuring the parameters of low-frequency noise in the cases of a given ultimate measurement error of power spectral density and a given duration of a single measurement. The proposed algorithms include the preliminary evaluation of the parameter of shape of the spectrum with subsequent measurements of the power spectral density of noise for the optimal bandwidth of the filter. The optimal bandwidth of the filter is established according to the results of preliminary evaluation of the parameter of shape of the spectrum. In both cases, we obtain estimates of the gain in a sense of the mean value over the set (ensemble) of controlled products. We also discussed the possibility of adaptive or cognitive adjustment of the parameters of measuring system in the control process based on the results of evaluation of sample means in the training sample. PubDate: 2021-03-02

Abstract: A Bayesian approach to the construction of effective statistical estimates of parameters of distribution laws of random variables for the Poisson and Pareto laws, exponential and uniform laws is considered. An algorithm for constructing point and interval statistical estimates for the parameters of these laws has been developed. The results of comparison with the corresponding estimates obtained by the classical maximum likelihood method are presented. The proposed algorithm can be effectively applied in the development of measurement techniques, solution of measurement problems and the development of practical methods for identifying systematic measurement errors. PubDate: 2021-03-02

Abstract: Protection devices for respiratory organs with filtering and adsorption elements based on solid, particularly chemical, sorbents are examined. In order to ensure reliable operation of the specified respiratory device, it is necessary to monitor their residual life indicator. Factors are analyzed for the uncertainty of indirect measurement of the residual life indicator of the filtering and absorptive products, in the form of a plate and operating under conditions of convective blowoff with cleaning air. It is shown that for sorbent plates based on potassium superoxide KO2 0.8 mm thick, with relative humidity of the air 60–90%, and carbon dioxide CO2 concentration 1–4%, the primary uncertainty factor of an indirect measurement of the residual life indicator is the Biot number Bi, which characterizes the conditions of heat exchange from the surface of the plate. It has been experimentally established that for Bi = 0–0.08, the primary factor is up to 30% of the total measurement uncertainty of the residual life indicator. PubDate: 2021-03-01

Abstract: The problem of calibrating a simulator of the navigation signals of global navigation satellite systems in order to ensure the unity of measurements of coordinate and time facilities was examined. A method is provided of determining, with the use of an oscilloscope, a fractional part of a carrier frequency cycle in the radio-frequency circuit of the simulator, and of estimating the mean reference deviation of the error of simulator generation of a pseudo-distance on the carrier-phase. The essence of the method consists in determining the phase difference of two signals. Depending on the type of problem, this method of calibration can be used with different input data: for absolute calibration of the simulator with one radio-frequency output: the phase difference of the navigation signal generated by the simulator, and the reference harmonic signal; for relative calibration of the simulator with two or more radio frequency outputs: the phase difference between navigation signals generated by the simulator from the different radio-frequency outputs. The application is shown of the absolute calibration of the simulator by the carrier-phase for the solution of a problem of calibrating users’ navigation equipment by the carrier-phase, which will substantially simplify the implementation of the promising Integer-PPP technology. The use of the relative calibration of the simulator, in order to determine the precise characteristics of goniometric navigation equipment for its development and tests, is presented. PubDate: 2021-03-01

Abstract: An improved monochromatic radiation source with spectral width 4 nm based on a supercontinuum laser and double monochromator is introduced into a unit based on an absolute cryogenic radiometer in order to increase the precision of measurement of spectral sensitivity in the range 0.9–1.6 μm. A feedback system that supports stabilization of the power of monochromatic radiation with standard deviation 0.025% is developed. The power of optical radiation in the plane of the detector and/or power of the absolute cryogenic radiometer varies from 0.1 to 1.5 mW. The spectral distribution of the power of the newly developed source in different operating regimes of the supercontinuum laser is presented. PubDate: 2021-03-01

Abstract: The use of micro-electro-mechanical system (MEMS) accelerometers in aircraft control and navigation systems is of great interest. In this paper, a MEMS accelerometer with optical reader based on a two-channel Fabry–Perot interferometer is considered. To improve the accelerometer accuracy, it is proposed to analyze the fractional part of the interference band. The authors have studied the linear acceleration effect on the variation of output signal of the optical reader at various beam sensor parameters, as well as the variation of interferometer transmittance at different mirror reflectivity. Based on the interferometer transmittance vs. displacement relationships, the channel switching conditions were established to enable bypassing low-sensitivity zones. A method of optical signal processing has been developed, which generates the output value by concatenating the coarse measurement results and calculating a fine component. The proposed processing method makes it possible to increase the accuracy of the acceleration measurement results without changing the conversion range. PubDate: 2021-03-01

Abstract: Problems related to the use of measurement systems and the variation of the parameters of measurement systems under the effect of different types of destabilizing factors, including time, are considered. Meanwhile, the primary elements of the measurement tract, i.e., sensors and conversion instruments, are the most susceptible to this influence. Deviations of the values of the parameters of testers from the nominal values leads to major errors in the estimation of an unknown input signal, which results in a need for current (i.e., in the course of use) identification of the tester. The problem of current identification of the parameters of a tester subjected to unknown input influences is solved. The procedure of identification is realized through the introduction of a secondary channel that transforms a measured quantity in the spatial domain. In this case, transformation of a measured quantity in the secondary channel of a structurally redundant tester has the form of a preliminary functional (nonlinear) transformation of mth degree of an input signal. The solution of the problem of current identification is considered for a linear static characteristic of the basic channel of a measuring transducer. The additional equation in the solution of the problem of current identification and performance of metrological self-control in a smart sensor is represented in the form of a regression relationship between the output signals of the secondary and basic channels of a structurally redundant tester. The unknown parameters of the regression equation are determined from the results of processing time samples of the output signals of the secondary and basic channels by the method of least squares. Dependences of the mean-square error of measurements of the input quantity on the mean-square strength of the noise of measurements in the output signals of the structurally redundant tester, the dynamic behavior of the variation of the input signal, and the degree of nonlinearity m of the preliminary functional transformation in the secondary measurement channel are presented. In the course of the investigation it is discovered that the form and spectrum of the input signal do not significantly affect the precision of the measurements. It is shown that preliminary quadratic (m = 2) transformation of an input signal in the secondary channel of a minimum redundancy sensor produces the highest level of measurement precision. The results of the investigation may be used for metrological self-control in smart sensors or smart measurement systems. PubDate: 2021-03-01

Abstract: A statistical test of the “extraordinary” evidence for the “accelerated expansion of the Universe” owing to the “cosmic jerk” over a range of red shifts z = 0.46 ± 0.13 and for z = 0.763 based on data from SN Ia supernovae for which photometric distances have been determined is carried out. The transition from “deceleration” to “acceleration” is treated as a “disruption”– a change in the structure and parameters of the model for the cosmological distance scale. It is shown that the data from different sources do not form a compositionally uniform set. “Discrepancies” in the model for the scale are discovered for z = 0.44–0.48 in a sample of 10 SN Ia over an interval from z = 0.30–0.97 according to data from the High-Z Supernovae Search Team and for red shifts z = 0.763–0.828 in a sample of 42 SN Ia over an interval from z = 0.172–0.83 according to data from the Supernovae Cosmology Project. The reason for these “discrepancies” may be an unbalanced and random distribution of the SN Ia over the observed range of red shifts for a scale with a clearly distinct non-metric character. PubDate: 2021-03-01

Abstract: A brief overview of the history of the origin and development of the cosmological distance scale based on redshift is given. Statistical aspects of the problem of calibration of scales of this type are considered on the analogy with the problems of calibration of measuring instruments. An analysis is presented of the first data on the basis of which the “accelerating expansion of the Universe” was detected. The metrological consequences of anisotropy for distance scale are analyzed. PubDate: 2021-02-22

Abstract: The accurate measurement of the internal dimensions of closed cavities with conducting walls without the access of measuring tools inside the cavities is relevant when measuring the parameters of radio materials and the dimensions of metal vessels with limited access to them, when clarifying the Boltzmann constant, and when conducting gas thermometry and other tasks. This article presents the results of measuring the internal dimensions of cavities, namely, microwave cavity resonators, by considering the range of their resonant frequencies. The differences between the eigenfrequency and resonant frequency in a resonator with perfectly conducting walls and those in a real resonator with impedance walls are clarified. The types of functions suitable for describing the resonant amplitude-frequency characteristics of real resonators are analyzed. This article also presents the results of measuring the inner diameter and length (height) of microwave resonators from the State Primary Standard for the units of complex dielectric permeability (GET 110-2012) with frequencies ranging from 1 to 178.4 GHz. PubDate: 2021-01-29 DOI: 10.1007/s11018-021-01862-z

Abstract: To the article “Spectral, Dosimetric, and Metrological Characteristics of Radiochromic Radiation-Sensitive Compositions,” by V. P. Tenishev, Vol. 63, No. 8, pp. 653–659, November, 2020. PubDate: 2021-01-28 DOI: 10.1007/s11018-021-01863-y

Abstract: The problem of the metrological provision of generators of high-voltage voltage pulses with subnanosecond front rise time has been solved, as well as pulsed voltage splitters used in power engineering, aviation, and aerospace industries. As a result of the completion of the State Primary Special Standard for units of the intensities of pulsed electrical and magnetic fields with pulse front rise times in the range 0.1–10.0 ns per GET 148-2013, a mode of implementing the reproduction of the unit of high transient electric voltage with a minimum pulse front rise time of 100 ps has been implemented. The uncertainties of reconstituting the unit of high transient electric voltage, obtained by numerical modeling with the Monte Carlo method, are evaluated, as well as in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM). Likewise, the error of reproduction of the unit according to GOST 8.381-2009, “GSI. Standards. Methods of Expression of Precision,” is evaluated. PubDate: 2021-01-23 DOI: 10.1007/s11018-021-01859-8

Abstract: The use of the liquid PES-3 in a high-pressure piston pair is modeled and the parameters of the piston pair are determined. Equations are derived for a mathematical model describing the variation of the pressure in the gap between the piston and cylinder. The distribution of the pressure in the gap between the piston and cylinder is calculated for piston pressures below 1.6 GPa. The profiles of the gaps between a deformed piston and the cylinder are calculated for different piston pressures and the dependences of the piston downstroke velocity and gap efficiency on the piston pressure are calculated for different gaps of the undeformed piston pair. The results of this study can be used for the design of piston pairs operating in PES-3 fluid at pressures ranging from 0.01–1.6 GPa. PubDate: 2021-01-23 DOI: 10.1007/s11018-021-01857-w

Abstract: The first-class State Working Standard of units of wavelength in the range from 1.25 to 20.00 μm and of units of wavenumber in the range from 500 to 8000 cm–1 developed at the All-Russia Research Institute of Optophysical Measurements on the basis of an infrared Fourier spectrometer is presented. The units of wavelength and units of wavenumber are transmitted to working standards in the course of a measurement (performed by an infrared Fourier spectrometer) of the positions of the radiation peaks from two laser sources incorporated into GET 170-2011, the State Primary Special Standard of the units of length and propagation time of a signal in an optical cable, mean power, attenuation, and wavelength for fiber-optic communication systems and information transmission systems. The working standard reproduces the spectral scale with the use of an interference pattern produced by a built-in He–Ne laser in the course of measurements of the spectral distribution of the strength of the internal source. Propagation of the wavelength scale in the range 1.25–20.00 μm and of the wavenumber scale in the range 500–8000 cm–1 is achieved through the introduction of corresponding correction factors to the results of measurements. An accuracy chart that establishes the traceability of an instrument used to measure wavelength and wavenumber to GET 170–2011 is developed and presented. PubDate: 2021-01-23 DOI: 10.1007/s11018-021-01853-0

Abstract: The phenomenon of jitter is examined in image-converter (electro-optical) streak cameras used for studies of high-speed processes. A method for measuring jitter in streak cameras operating in a linear scan mode for the pulsed optical signal is proposed. An experimental apparatus that realizes this measurement technique is described. This apparatus is used at VNIIOFI to check jitter in commercial image-converter streak cameras for compliance with specifications or the technical requirements of customers. PubDate: 2021-01-21 DOI: 10.1007/s11018-021-01856-x

Abstract: This article presents the technique of radio interferometry measurements and a theoretical estimate of the measuring error of the reflecting surface displacement. The displacements are measured using microwave radio interferometers. This article describes the automated complex Micron design as well as its operating principle. The complex is designed to experimentally determine the error in measuring the reflecting surface displacement as well as to conduct primary and periodic verification of microwave radio interferometers. The complex Micron comprises a measuring tool of the precision class 3, that is, an incremental linear displacement transducer LIR-7A, which measures the reflecting surface displacement of the test object. Verification of the longitudinal displacement measuring line is provided for the complex Micron so that the LIR-7A transducer can be verified without dismantling it. Parallel slip gauges or similar standards can be used as the initial standard for verification. The measured displacement values, determined during verification and obtained through an alternative method providing the required accuracy of radio interferometry measurements, were compared. PubDate: 2021-01-21 DOI: 10.1007/s11018-021-01861-0

Abstract: The situation was analyzed that has been established in the International System of Units (SI) as a result of adoption of the recommendation of the International Committee of Weights and Measures (CIPM) in 1980, which proposed to consider plane and solid angles as dimensionless derived quantities. It was shown that such decision was based on a misunderstanding of the mathematical formula, relating the arc length of a circle with its radius and corresponding central angle, as well as series expansions of trigonometric functions. As follows from the conducted analysis, the plane angle value does not depend on any of the SI quantities and should be treated as a base quantity, while its unit (radian) should be added to the population of base SI quantities. Therefore, the value of a solid angle becomes a derived quantity from a plane angle, and its unit (steradian) represents a coherent derived unit equal to a square radian. PubDate: 2021-01-21 DOI: 10.1007/s11018-021-01855-y