Transfer function of open ear importance in assessment of hearing protection devices noise reduction

Introduction. Objective assessment of the noise redaction (NR) of individual hearing protection devices (HDP) in industrial conditions is actual problem despite numerous studies in this direction in many countries. This study aimed to implement the F-MIRE method for measuring the NR of HDPs, considering the transfer function of the outer ear. Materials and methods. HDP performance indicators measured by the real ear attenuation threshold (REAT) method in the free field, do not fully reflect the protective properties of HDP in specific production conditions and for a specific employee, according to many researchers. The measurement method using two microphones, called Field-MIRE (F-MIRE), allows you to determine NR as the difference in sound pressure, external noise and noise inside the external auditory meatus (EAM). But since these microphones are located in different acoustic conditions, it becomes necessary use at least two blocks of correction coefficients to get real results. One block - considering the properties of the acoustic probe, the second - should consider the transfer function of open ear. The measurements of the TFOE in 18 volunteers and the evaluation of the NR of the SOMZ-1 "Jaguar" earmuff in industrial conditions were carried out. Results. This study has shown the effectiveness of the implementation of the F-MIRE method for an adequate assessment of the NR of earmuff in industrial conditions. The special headband uses for measuring the TFOE allows you to standardize the location of measuring microphones relative to the volunteer's head and reduce the uncertainty of measurements. Unlike the REAT method with binaural listening in a free field, the F-MIRE method allows you to determine the TFOE for each ear of an employee. Our research has shown that TFOE differences between the right and left ears one-man can be significant. Conclusion. The NR determination by the difference of sound pressures measured by an external microphone and a MIRE microphone, without considering the acoustic properties of the outer ear underestimates both spectral and single-digit NR indicators.

Methodology for assessing the uncertainty of measurements of mechanical stresses by the ultrasonic method with the help of an optical-acoustic separate-combined transducer

The work is devoted to the ultrasonic method of controlling mechanical stresses using ultrasonic head waves. The factors that contribute to the result of measurements of mechanical stresses include: the propagation velocity of the head ultrasonic wave, the temperature of the environment and the object of control, the coefficients of acoustoelastic and thermoacoustic coupling, parameters of the optical-acoustic transducer. The contribution of each of these factors to the results of measurements of mechanical stresses is assessed. A technique for assessing the uncertainty of measurements of mechanical stresses by the ultrasonic method using head waves has been developed.

Survey Management During Geosteering

Geosteering is usually responsible for addressing geological uncertainties, such as the uncertainty in the position of the horizon structure or the structural dip angle. During drilling, the directional survey measurements are taken as true, whilst the uncertainties related to the instruments are not considered. Measurement errors cannot be completely excluded, but they can be reduced to a minimum (reducing the "ellipse of uncertainty" of measurements) by considering the variability of the Earth's magnetic field and the influence of the external factors on the tool (by employing quality control and correction of directional measurements), as a result, reducing the risks of crossing the fluid contacts by the wellbore. This work is devoted to the methods of detecting and minimizing the inclinometer measurement error while drilling, as well as the application of the results for geological support of drilling. The article describes the principle of the methodology for correcting the inclinometer measurements while drilling and indicates the cases in which the correction method is applicable. The paper considers the prerequisites for using the measurement quality control method and tools to reduce the measurement error in these cases. The possibility of using the method of geomagnetic referencing IFR, as well as methods for correcting measurements of the telemetry system BHA Sag and MSA, to fulfill geological tasks is considered. This paper provides an example of quality control of directional measurements after drilling a well with an extended horizontal section. In the course of the work, the values of measurement errors along the vertical and lateral were established at a large deviation from the wellhead of the considered well. Attention is focused on the analysis of the identified inclinometry errors, their consequences and impact on the geological drilling of the wellbore and considered an example of improving the quality of geological support using the method of correcting directional measurements while drilling.

Validation of a 1:8 Scale Measurement Stand for Testing Airborne Sound Insulation

This paper contains a detailed description of the design and validation of a measurement stand for testing the airborne sound insulation of specimens made at a small scale. The stand is comprised of two coupled reverberation rooms in which the geometry represents the full-size reverberation rooms used at the AGH University of Science and Technology at a 1:8 scale. The paper proves that both the scaled measurement stand and the testing methodology conform to the ISO 10140 standards, and that the obtained measurement uncertainty does not exceed the maximum values specified in ISO 12999-1. Moreover, the calculated uncertainty of measurements obtained for the 1:8 scale stand is comparable with the typical uncertainty given in ISO 12999-1 and the uncertainty obtained on the full-scale measurement stand. In connection with the above, the authors have proved that by using the scaled-down measurement stands, one can obtain reliable and repeatable results of measurements of airborne sound insulation.

Estimating the uncertainty of measurements of thermal conductivity of thin films of thermoelectrics with the 3-omega method

Using the method of computer simulation, the uncertainty of measurements of the thermal conductivity of silicon, which is often used as substrates, and also thin films based on bismuth, is estimated. The influence of the application of an additional dielectric layer between the thermoelectric film and the resistive heater on the measurement results is shown.

Static Attitude Determination Using Convolutional Neural Networks

The need to estimate the orientation between frames of reference is crucial in spacecraft navigation. Robust algorithms for this type of problem have been built by following algebraic approaches, but data-driven solutions are becoming more appealing due to their stochastic nature. Hence, an approach based on convolutional neural networks in order to deal with measurement uncertainty in static attitude determination problems is proposed in this paper. PointNet models were trained with different datasets containing different numbers of observation vectors that were used to build attitude profile matrices, which were the inputs of the system. The uncertainty of measurements in the test scenarios was taken into consideration when choosing the best model. The proposed model, which used convolutional neural networks, proved to be less sensitive to higher noise than traditional algorithms, such as singular value decomposition (SVD), the q-method, the quaternion estimator (QUEST), and the second estimator of the optimal quaternion (ESOQ2).

Comparative analysis of the accuracy requirements of the equipment for determining the mean integral refractive index of air using different realizations of the gradient method

The speed of propagation of electromagnetic waves in the Earth’s atmosphere differs from the speed of their propagation in a vacuum, which is one of the main factors that have a significant impact on the accuracy of long distance measurement. This influence is taken into account in long distance measurement with the correction for the mean integral group refractive index of air, which depends on such meteorological parameters as temperature, atmospheric pressure and relative air humidity. The purpose of this work is to compare the accuracy requirements for equipment designed to measure temperature, pressure, and relative humidity required to determine the above correction by the gradient method using the Euler-Maclaurin quadrature formula (hereafter, the Euler-Maclaurin method) and the formula based on Hermite interpolation polynomials (hereafter, the Hermite method). The requirements for the uncertainty of measurements carried out with the sensors of meteorological parameters, allowing to find the mean integral group refractive index of air, providing length measurements of the baselines of up to 5 km with an expanded uncertainty of not more than 1 mm, are established. Keywords: atmosphere; mean integral group refractive index of air; laser long distance measurement

METHODOLOGY FOR EVALUATION THE UNCERTAINTY OF MEASUREMENT OF MECHANICAL STRESS BY THE ULTRASONIC METHOD WITH THE HELP OF AN OPTICAL-ACOUSTIC SEPARATE-COMBINED TRANSDUCER

The work is devoted to the ultrasonic method for controlling mechanical stresses using ultrasonic head waves. The speed of the head ultrasonic wave is the highest, which allows it to be recorded stably among other types of ultrasonic waves and noises. To determine mechanical stresses, registration of the relative change in the velocity of propagation of the head ultrasonic wave is used, corrected for the change in the measured value caused by the change in the temperature of the test object. Thus, mechanical stresses are not measured directly, but the sources of uncertainty are the results of measurements of the propagation velocity of the head ultrasonic wave, the temperature of the environment and the test object, the coefficients of acoustoelastic and thermoacoustic coupling, and the parameters of the optical-acoustic transducer. The contribution of each of these factors to the results of measurements of mechanical stresses is estimated. On the basis of GOST 34100.3–2017, a method has been developed for asessing the uncertainty of measurements of mechanical stresses by the ultrasonic method using head waves. The dependence of the expanded measurement uncertainty on the value of the measured mechanical stresses was obtained. This dependence shows that measurements of mechanical stresses in the range of less than 100 MPa have an uncertainty of more than 10 % of the measured value. When measuring mechanical stresses over 200 MPa, the measurement uncertainty will not exceed 4 % (at a confidence level of 95 %).The proposed approach to assessing the uncertainty of measurements of mechanical stresses can be useful in the development of requirements for the used measuring instruments, alignment samples and control objects, as well as in the development of methods for monitoring mechanical stresses by the ultrasonic method using an optical-acoustic separate-combined transducer.

Estimation of the error of the simplified algorithm of processing of functions of deflations of deformed frames of bodies of rolling stock

The study is aimed at assessing the size of the error that arises when processing the results of examining the geometric characteristics of the bearing structures of rolling stock units using an algorithm without using trigonometric functions. The object of the research is a method of simplified alignment of the deflection function of body frame beams to the horizontal plane. One of the biggest problem areas is the lack of understanding by some customers of the work of the possibility of using this algorithm due to the lack of information about the errors that arise in the simplified calculation. The study was carried out by comparing the results of processing the initial data by two methods, obtained during the work on the inspection of the state of the supporting structures of the unit of the shunting diesel locomotive TGM6. One method, the algorithm of which is the subject of this study, assumes that no complex calculations are used during data processing. The second method involves the use of an algorithm for aligning the deflection functions of the body frame beams of a rolling stock unit of railways in the horizontal plane, taking into account all trigonometry tools, which will exclude the accompanying calculation errors of the simplified method. After processing the initial data, two sets of results were obtained – with the desired calculation error and without. Comparison of these datasets yielded an error value for frame tilt of 5.7. For clarity, the size of the error was compared with the expanded uncertainty values of the main sources of uncertainty in the methodology for examining the bearing structures of rolling stock. On the basis of the analysis of two methods of leveling the inclination to the horizontal plane of the deformed rolling stock body frame, the expediency of such an approach has been proved. The results obtained make it possible to reasonably use the Simplified approach to processing the data obtained during the survey of the geometric characteristics of the rolling stock. If necessary, the developed mathematical model can be used to improve the accuracy of calculating the uncertainty of measurements of geometric characteristics, as well as for use in the study of modification of existing or development of new measurement techniques

Substantial heterogeneity of carbon and oxygen stable-isotope compositions of single layers or specimens of natural carbonate materials: New evidence from replicate sampling of continental carbonates affirms previous evidence from marine limestones

ABSTRACT The uncertainty of measurements of carbon and oxygen stable-isotope ratios of carbonate materials is commonly assumed to be the analytical uncertainty determined from replicate analyses of single samples, but this ignores the possibility that heterogeneity of the material studied is greater than the analytical uncertainty. To test this question, we took eight samples from each of 13 layers or specimens of various non-marine (“continental”) carbonates and found ranges of δ13C and δ18O of 0.3 to 5.1‰, all exceeding the range of the typical lab-reported analytical uncertainty, ± 0.1‰, placed around single samples. These results are similar to previous replicate sampling of marine limestone layers, which revealed ranges of 0.2 to 2.8‰. Both sets of results, and other published data, demonstrate that analytical uncertainty derived from replicate analysis of a single sample is not a valid estimate of the uncertainty of δ13C or δ18O values characterizing a layer or specimen, and they remind us that we should not place great credence in anomalies or events defined by single samples of layers or specimens, regardless of the replication of analysis of that single sample. Our results indicate that the required layer-level or specimen-level uncertainty can be derived only from replicate sampling at different locations in layers or specimens, and that the layer-level or specimen-level uncertainty is inevitably greater than typical lab-reported analytical uncertainty. Credibility of anomalies or events in time series would be increased by replicate sampling of a random or dispersed subset of layers to estimate the variability of all layers and/or by replicate sampling of layers at and around a potential but unconfirmed event. The significance of the variability discussed above is evident in use of δ18O data to estimate paleotemperatures, where a difference of 1‰ in δ18O implies a difference of 4°C in temperature. Use of a single sample resulting in mischaracterization of the δ18O of an ancient material by 1.5‰ relative to the true mean for that material (which our results suggest is quite possible) would lead to a corresponding misestimation of temperature of 6°C, a significant difference in paleoenvironmental studies.