РАЗРАБОТКА НЕЧЕТКОЙ НЕЙРОННОЙ СЕТИ ДЛЯ ИНТЕРПРЕТАЦИИ РЕЗУЛЬТАТОВ АНАЛИЗА РАСТВОРЕННЫХ В МАСЛЕ ГАЗОВ

Purpose. The purpose of this paper is a diagnosis of power transformers on the basis of the results of the analysis of gases dissolved in oil. Methodology. To solve this problem a fuzzy neural network has been developed, tested and trained. Results. The analysis of neural network to recognize the possibility of developing defects at an early stage of their development, or growth of gas concentrations in the healthy transformers, made after the emergency actions on the part of electric networks is made. It has been established greatest difficulty in making a diagnosis on the criterion of the boundary gas concentrations, are the results of DGA obtained for the healthy transformers in which the concentration of gases dissolved in oil exceed their limit values, as well as defective transformers at an early stage development defects. The analysis showed that the accuracy of recognition of fuzzy neural networks has its limitations, which are determined by the peculiarities of the DGA method, used diagnostic features and the selected decision rule. Originality. Unlike similar studies in the training of the neural network, the membership functions of linguistic terms were chosen taking into account the functions gas concentrations density distribution transformers with various diagnoses, allowing to consider a particular gas content of oils that are typical of a leaky transformer, and the operating conditions of the equipment. Practical value. Developed fuzzy neural network allows to perform diagnostics of power transformers on the basis of the result of the analysis of gases dissolved in oil, with a high level of reliability.Разработана и обучена нечеткая нейронная сеть для интерпретации результатов хроматографического анализа растворенных в масле газов. Предложено определять функции принадлежности лингвистических термов с учетом функций плотностей распределения концентраций газов для трансформаторов с различным состоянием. Выполнено тестирование обученной сети на независимой выборке. Проанализированы возможности нейронных сетей распознавать развивающиеся дефекты на ранней стадии их развития, или рост концентраций газов в исправных трансформаторах, после аварийных воздействий со стороны электрических сетей

Determination of the Water Jet Geometric Parameters Depending on the Type of Nozzle and Jet Operation Mode

Introduction. The article describes the process of considering the geometric parameters of water jet depending on a water jet operation mode and nozzle type. Within the framework of the study of hydraulic soil treatment in the under-tree zones, it became necessary to study the water jet parameters when using different types of nozzles. There was need to determine the geometric parameters of water flow for calculating the cross-sectional area and determining the structural features of the water jet formation. These characteristics are important for a complete description, subsequent study and calculation of water jet action during hydraulic soil treatment; they also allow studying the real shape and structure of the water jet when using different types of nozzles. Aim of the study. The study is aimed at determining the geometric parameters of the water jet for different nozzles including turbo cutters located at different heights. Materials and Methods. To solve this problem, there was developed a test bench, on four pillars, to which the adapter of the supply line of the high-pressure apparatus with replaceable nozzles is fixed. To fix the position and shape of the water jet with a certain frequency, a Basler ace acA1920 camera was used. There was also used a high-pressure apparatus with a maximum pressure of P = 140 MPa, a maximum flow rate of Q = 360 l/h. A standard nozzle with a flat jet, a standard turbo nozzle, and a turbo nozzle of the developed design were used. The geometric parameters of the water jet section were measured from the photographs obtained. Results. From the photos obtained, it can be seen that the rotating water stream entering the turbo nozzle of its own design and the standard turbo nozzle disintegrates from rapid rotation, forming a cone, the cross-sectional area of which is a circle, and affects the soil surface. A flat jet is characterized by a rectangular cross-section. Discussion and Conclusion. According to the results of the study we can draw the following conclusions, the nozzle of the proposed design allows creating water jets of the largest area, which should provide an increase in the working width and, as a consequence, an increase in productivity and quality of soil surface treatment in mainline plantations. This study will also make it possible to analyze the structure of the jet during its operation

ANALYSIS OF OPERATING CONDITIONS AND MODES INFLUENCE ON TECHNICAL STATE OF MAIN INSULATION OF HIGH-VOLTAGE BUSHINGS OF DIFFERENT DESIGN

The results of the analysis of the influence of operating conditions and design of high-voltage bushings on the values of dielectric loss tangent of high-voltage bushing basic insulation. For analysis a model of two-factor cross-sectional dispersion analysis, which allows to simultaneously evaluate the influence of two factors and evaluate the effect of their interaction is used. In the model used, it is assumed that the effects of changes in the levels of factors are non-additive, that is, the difference in mathematical expectations between any two levels of one factor is not the same for any levels of the other. Testing the hypothesis of the significance of the influence of factors and their interactions is performed using the Fisher criterion. This method was implemented in the form of the author’ program «two-factor dispersion analysis». The results of periodic monitoring of the state of high-voltage bushings of 110, 220 and 330 kV with different types of insulation were used as initial data. Using the model of two-factor cross-sectional dispersion analysis, it was found that the aging intensity of the main insulation of bushings is influenced by both the operating conditions and the design features of the bushings. Maximum permissible values of diagnostic indicators of high-voltage bushings should be normalized taking into account such factors as nominal voltage, type of protection and type of insulation, load of bushings and the composition of consumers. Since, based on the analysis performed, it was established that these factors have a significant impact on the values of diagnostic indicators of insulation of bushings. According to the results of the analysis performed, it was established that such factors as the type of bushing and phase do not have a significant effect on the change in the values of diagnostic indicators of high-voltage bushings, and, therefore, they can be ignored when determining the maximum permissible values of the indicators

Acoustoelectric current and pumping in a ballistic quantum point contact

The acoustoelectric current induced by a surface acoustic wave (SAW) in a ballistic quantum point contact is considered using a quantum approach. We find that the current is of the "pumping" type and is not related to drag, i.e. to the momentum transfer from the wave to the electron gas. At gate voltages corresponding to the plateaus of the quantized conductance the current is small. It is peaked at the conductance step voltages. The peak current oscillates and decays with increasing SAW wavenumber for short wavelengths. These results contradict previous calculations, based on the classical Boltzmann equation.Comment: 4 pages, 1 figur

Measurements of integral muon intensity at large zenith angles

High-statistics data on near-horizontal muons collected with Russian-Italian coordinate detector DECOR are analyzed. Precise measurements of muon angular distributions in zenith angle interval from 60 to 90 degrees have been performed. In total, more than 20 million muons are selected. Dependences of the absolute integral muon intensity on zenith angle for several threshold energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region of zenith angles and threshold energies have been obtained for the first time. The dependence of integral intensity on zenith angle and threshold energy is well fitted by a simple analytical formula.Comment: 4 pages, 4 figures, 1 tabl

Coulomb Drag in Coherent Mesoscopic Systems

We present a theory for Coulomb drag between two mesoscopic systems. Our formalism expresses the drag in terms of scattering matrices and wave functions, and its range of validity covers both ballistic and disordered systems. The consequences can be worked out either by analytic means, such as the random matrix theory, or by numerical simulations. We show that Coulomb drag is sensitive to localized states, which usual transport measurements do not probe. For chaotic 2D-systems we find a vanishing average drag, with a nonzero variance. Disordered 1D-wires show a finite drag, with a large variance, giving rise to a possible sign change of the induced current.Comment: 4 pages including 2 figures. Minor changes. Accepted for publication in Phys. Rev. Let

Pumping in an interacting quantum wire

We study charge and spin pumping in an interacting one-dimensional wire. We show that a spatially periodic potential modulated in space and time acts as a quantum pump inducing a dc-current component at zero bias. The current generated by the pump is strongly affected by the interactions. It has a power law dependence on the frequency or temperature with the exponent determined by the interaction in the wire, while the coupling to the pump affects the amplitudes only. We also show that pure spin-pumping can be achieved, without the presence of a magnetic field.Comment: 13 pages,2 figure

Quantum pumping: Coherent Rings versus Open Conductors

We examine adiabatic quantum pumping generated by an oscillating scatterer embedded in a one-dimensional ballistic ring and compare it with pumping caused by the same scatterer connected to external reservoirs. The pumped current for an open conductor, paradoxically, is non-zero even in the limit of vanishing transmission. In contrast, for the ring geometry the pumped current vanishes in the limit of vanishing transmission. We explain this paradoxical result and demonstrate that the physics underlying adiabatic pumping is the same in open and in closed systems.Comment: 4 pages, 2 figure

LARGE AREA HODOSCOPES FOR MUON DIAGNOSTICS OF HELIOSPHERE AND EARTH'S MAGNETOSPHERE

Muon diagnostics is a technique for remote monitoring of active processes in the heliosphere and the magnetosphere of the Earth based on the analysis of angular variations of muon flux simultaneously detected from all directions of the upper hemisphere. To carry out muon diagnostics, special detectors – muon hodoscopes – which can detect muons from any direction with good angular resolution in real-time mode are required. We discuss approaches to data analysis and the results of studies of various extra-terrestrial processes detected by means of the wide aperture URAGAN muon hodoscope