https://rep.bntu.by/handle/data/79258 Wed, 22 Apr 2026 18:42:27 GMT 2026-04-22T18:42:27Z https://rep.bntu.by/handle/data/79286 Контраст изображения объекта, наблюдаемого в условиях задымления, при поляризационной фильтрации излучения, рассеянного частицами дыма Кицак, А. И. Целью работы являлось исследование контраста изображения объекта, наблюдаемого в задымленной среде, с применением поляризационной фильтрации излучения, рассеянного частицами дыма в сторону наблюдателя, и сопоставление данного контраста с контрастом изображения, формируемого без фильтрации, для оценки возможности разработки комплекта оптических принадлежностей пожарного-спасателя, улучшающего видение объектов в условиях дымообразования при пожаре. Достижение поставленной цели осуществлялось методом экспериментального моделирования процесса передачи изображений чёрно-белого объекта с резкой границей перехода чёрное / белое через различные типы аэрозолей дыма с применением поляризационной фильтрации излучения, рассеянного частицами дыма, и без фильтрации и оценке контрастов изображений. Проведены исследования контрастов изображений для различных оптических плотностей дымов в двух схемах регистрации, когда приёмная оптическая система расположена вблизи источника подсветки объекта на расстоянии ≈ 150 мм от него, и когда она расположена на удалении от источника подсветки объекта на расстоянии ≈ 800 мм. Установлено, что способ формирования изображения объекта с применением поляризационной фильтрации излучения помехи обратного рассеяния (ПОР) позволяет снизить скорость уменьшения контраста изображения с увеличением оптической плотности дыма в сравнении с регистрацией изображения без фильтрации ПОР. Существенная разница в контрастах изображений, регистрируемых с поляризационной отсечкой ПОР и в отсутствие фильтрации, наблюдается для «светлых» дымов (пиролиз древесины, тление хлопка) на средних удельных оптических плотностях дыма. Полученные результаты могут быть использованы при разработке оптических принадлежностей пожарного-спасателя для улучшения условий наблюдения объектов в неблагоприятных условиях видения: задымлении, парообразовании, тумане. Wed, 01 Jan 2020 00:00:00 GMT https://rep.bntu.by/handle/data/79286 2020-01-01T00:00:00Z https://rep.bntu.by/handle/data/79282 Analysis of Requirements and the Feasible Limit for Error Reduction in Two-Parameter Magnetic Determination of Steels’ Hardness Sandomirski, S. G. All measurements of mechanical properties of materials in the magnetic structural analysis are indirect and relationships between the measured parameters are correlated. An important physical parameter of steel is hardness. An increase in the correlation coefficient R and a reduction in the standard deviation (SD) are achieved when controlling the hardness of steels with two-parameter magnetic methods compared to methods that use a single measured parameter. However, the specific conditions and requirements for application of the two-parameter methods remain unclear. The purpose of this article was to analyze conditions and the achievable error reduction limit for two-parameter indirect determination of steels hardness and to compare those with one-parameter methods. In particular, we considered the mean Square Deviation (SD), σF , of indirect calculation of the physical quantity F using two measured parameters x1 and x2 that are correlated with F. It was found that reduction of σF is most pronounced when x1 and x2 are inversely correlated with the maximum modulus |R| of the correlation coefficient R between them. The most significant reduction in σF occurs at similar values of the SDs σ1 and σ2 between the true value of F and the values calculated based on the results of indirect measurements of F using each of the parameters x1 and x2 . The Results of the analysis are confirmed by an example of reduction in SD when determining the hardness of carbon steels by measuring their remanent magnetization and coercive force compared to use any one of these parameters. This result can be applied to measurements in non-destructive testing and in related fields of physics and technology. The Results of the analysis allow us to compare different parameters for indirect two-parameter determination of a physical quantity, to select the optimal parameters, and to evaluate the minimum achievable measurement error of a physical quantity by a two-parameter method before performing the measurements. Wed, 01 Jan 2020 00:00:00 GMT https://rep.bntu.by/handle/data/79282 2020-01-01T00:00:00Z https://rep.bntu.by/handle/data/79281 Application of Two-Channel Principle in Measuring Devices to Compensate for Disturbing Influences of Unknown Physical Nature Nesterov, V. N.; Li, A. R. The article notes the advantages of the method of constructing absolutely invariant measuring transducers for working in conditions with disturbing influences. However, this method is not universal. Its limitations are due to the impossibility of "symmetric" transmission of all disturbing influences into parallel measuring channels. A broader interpretation of the two-channel principle is proposed to overcome these limitations. The aim of the study was to substantiate and implement a method for constructing quasi-invariant measuring transducers and systems that retain their metrological characteristics under external disturbances of unknown physical nature. The theory that develops the two-channel principle to a full-fledged technological method is presented in the article. The theory includes the necessary and sufficient conditions for physical feasibility this method. Two fundamental tasks have been solved in the work. The first task is to identify signs that reflect the essence of the technological method in to specific cases and the second is to implement a methodology that allows these signs to be effectively applied in practice. In the examples, a complex of technologies is defined for groups of elements of quasi-invariant transducers that provide compensation of the influencing factors acting on them with acceptable accuracy. There are significant advantages in discussed method. It gives hope for acceptable measurement results under conditions when character and even physical principle of influencing a priori are unknown. Wed, 01 Jan 2020 00:00:00 GMT https://rep.bntu.by/handle/data/79281 2020-01-01T00:00:00Z https://rep.bntu.by/handle/data/79280 Determination of Parameters of Electrode Metal Transported Drops by Simulation and Visualization Ilyaschenko, D. P.; Kryukov, A. V.; Lavrova, E. V.; Kuznetsov, M. A.; Verkhoturova, E. V. The nature of the molten electrode metal melting and transfer is the main process parameter of manual metal arc welding (MMA) with coated electrodes. It significantly affects the efficiency of the welding process. For this reason the relevant task is to identify the parameters of the transferred molten electrode metal drops and their further transfer into the weld pool with maximum accuracy. The aim of the given paper is to develop a method and visual representation of the form and the geometrics (volume, area, mass) of a molten electrode metal drop. We have developed the method of simulation modeling and visualization for molten electrode metal drops transfer and their parameters. It allows obtaining highly reliable input data to be used for developing and verification of mathematical models for the thermal fields distribution along the welded item surface. The algorithm is realized as the calculation programs for specifying the molten metal drop parameters and means of its geometrics and space form visualization. We used this method to specify a number of molten electrode metal drop parameters: volume, mass, center-of-gravity position, surface area. We have established that it is possible to conduct the measurements with maximum The suggested method significantly decreases the labor intensity of experimental studies aimed at specifying the size of electrode metal drops in comparison to the standard methods. When we know the size of the drops under certain welding conditions we can control the drop transfer process, i. e. reduce the heat input into the welded item and produce weld joints with the tailored performance characteristics. Wed, 01 Jan 2020 00:00:00 GMT https://rep.bntu.by/handle/data/79280 2020-01-01T00:00:00Z