Frequency estimation for short realization of radar signals II. Results of tests

The paper is devoted to the problem of short time delays measurement in radar systems. The algorithm which was proposed by authors in paper I [1] it compared with the generally used method based on fast Fourier transform. In numerical simulation estimation of random error are carried out depend on value of delay and value of signal to noise ratio. © 2014 Mikhail Ronkin, Ekaterina Khrestina and Aleksey Kalmikov

Computer vision system for the automatic asbestos content control in stones

The paper discusses the results of the first stage of research and development an innovative computer vision system for the automatic asbestos content control in stones veins at an asbestos processing factory. The discussed system is based on the applying of a semantic segmentation artificial neural networks, in particular U-Net based network architectures for solving both: the boundariesof stones segmentation and veins inside them. At the current stage, the following tasks were solved. 1. The discussed system prototype is developed. The system is allowing to takes images of the asbestos stones on the conveyor belt in the near-infrared range (NIR), avoiding the outer lighting influence, and processing the obtaining images. 2. The training, validation and test datasets were collected. 3. Substantiated the choice of the U-Net based neural network. 4. Proposed to estimate the resulted specific asbestos concentration as the average relation of all the veins square to all stones square on the image. 5. The resulted deviation between obtained and laboratory given results ofthe asbestos concentration is about 0.058 in the slope of graduation curve. The farther improvementrecommendations for the developed system are given. © Published under licence by IOP Publishing Ltd

Automatic Asbestos Control Using Deep Learning Based Computer Vision System

The paper discusses the results of the research and development of an innovative deep learning-based computer vision system for the fully automatic asbestos content (productivity) estimation in rock chunk (stone) veins in an open pit and within the time comparable with the work of specialists (about 10 min per one open pit processing place). The discussed system is based on the applying of instance and semantic segmentation of artificial neural networks. The Mask R-CNN-based network architecture is applied to the asbestos-containing rock chunks searching images of an open pit. The U-Net-based network architecture is applied to the segmentation of asbestos veins in the images of selected rock chunks. The designed system allows an automatic search and takes images of the asbestos rocks in an open pit in the near-infrared range (NIR) and processes the obtained images. The result of the system work is the average asbestos content (productivity) estimation for each controlled open pit. It is validated to estimate asbestos content as the graduated average ratio of the vein area value to the selected rock chunk area value, both determined by the trained neural network. For both neural network training tasks the training, validation, and test datasets are collected. The designed system demonstrates an error of about 0.4% under different weather conditions in an open pit when the asbestos content is about 1.5–4%. The obtained accuracy is sufficient to use the system as a geological service tool instead of currently applied visual-based estimations. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Enhancing Electroretinogram Classification with Multi-Wavelet Analysis and Visual Transformer

The electroretinogram (ERG) is a clinical test that records the retina's electrical response to light. Analysis of the ERG signal offers a promising way to study different retinal diseases and disorders. Machine learning-based methods are expected to play a pivotal role in achieving the goals of retinal diagnostics and treatment control. This study aims to improve the classification accuracy of the previous work using the combination of three optimal mother wavelet functions. We apply Continuous Wavelet Transform (CWT) on a dataset of mixed pediatric and adult ERG signals and show the possibility of simultaneous analysis of the signals. The modern Visual Transformer-based architectures are tested on a time-frequency representation of the signals. The method provides 88% classification accuracy for Maximum 2.0 ERG, 85% for Scotopic 2.0, and 91% for Photopic 2.0 protocols, which on average improves the result by 7.6% compared to previous work

Intersecting Solitons, Amoeba and Tropical Geometry

We study generic intersection (or web) of vortices with instantons inside, which is a 1/4 BPS state in the Higgs phase of five-dimensional N=1 supersymmetric U(Nc) gauge theory on R_t \times (C^\ast)^2 \simeq R^{2,1} \times T^2 with Nf=Nc Higgs scalars in the fundamental representation. In the case of the Abelian-Higgs model (Nf=Nc=1), the intersecting vortex sheets can be beautifully understood in a mathematical framework of amoeba and tropical geometry, and we propose a dictionary relating solitons and gauge theory to amoeba and tropical geometry. A projective shape of vortex sheets is described by the amoeba. Vortex charge density is uniformly distributed among vortex sheets, and negative contribution to instanton charge density is understood as the complex Monge-Ampere measure with respect to a plurisubharmonic function on (C^\ast)^2. The Wilson loops in T^2 are related with derivatives of the Ronkin function. The general form of the Kahler potential and the asymptotic metric of the moduli space of a vortex loop are obtained as a by-product. Our discussion works generally in non-Abelian gauge theories, which suggests a non-Abelian generalization of the amoeba and tropical geometry.Comment: 39 pages, 11 figure

High-resolution phase based method for FMCW short range radars

The paper deals with the problem of the using phase-based methods for frequency estimation in the frequency modulated continuum waves (FMCW) short-range radars in the case of high-resolution frequency estimation requirements. The equation is considered for frequency estimation by the least-square method of approximating the phase-to-time relation of the beat signal correlation function in the case of several significant components in the signal (such as valuable and interference signal-like tones). Solution is proposed for the equations by using the parametric (or subspace) decomposition of beat signals (such as eigenvector decomposition, EV). The numerical investigation shows that the bias of the frequency estimations by the proposed solution of the mentioned equation above has statistical properties similar to the method of estimation of signal parameters via rotational invariance techniques (ESPRIT). However, the proposed method does not require the double decompositions, and frequency of each eigenvector can be estimated separately. It is also shown that in the case of the unknown number of signal components the proposed method has the higher statistical properties than for such popular technique as the multiple signal classification method (MUSIC). © 2020 American Institute of Physics Inc.. All rights reserved.The work was supported by Act 211 Government of the Russian Federation, contract N 02.A03.21.0006

Analysis of processing features of ultrasonic flowmeters with FMCW signals

Поступила: 10.11.2018. Принята в печать: 28.12.2018.Received: 10.11.2018. Accepted: 28.12.2018.Проведен анализ и показана возможность использования ЛЧМ сигналов и гетеродинной схемы приема в УЗ ЛЧМ накладных время-пролетных расходомерах. Показано, что при измерениях расхода по разностям задержек в рамках рассмотренной модели в качестве информационного параметра может быть использована полная фаза сигналов биений (зависимость фазы сигнала от времени). Для данного случая построена модель сигнала биений. Проведен анализ предложенных в литературе, в том числе нами, алгоритмов в классе гладких центральных конечно-разностных оценок и их экспериментальное исследование в рамках поставленной задачи. Полученные результаты подтверждают эффективность рассмотренных методов измерения разностей задержек на практике. Рассмотренные методы позволяют быть реализованными на базе современных микроконтроллеров и при этом являются статистически эффективными в рамках рассмотренной задачи. Результаты проведенной работы доказывают эффективность использования рассмотренной модели сигналов и методов оценки их параметров в задачах измерений расхода при помощи ультразвуковых накладных ЛЧМ расходомеров.The paper deals with the analysis of features of frequency-modulated continuous-wave (FMCW) signals and heterodyne scheme of receiving in ultrasonic clamp-on time-of-flight flowmeters It is demonstrated that the full phase of time relation may be applied as the information parameter in the case of measuring the time delay difference in the considered task. The model of beat signal for this task is proposed. The carried on analysis of existed (including those proposed by authors) algorithms in the class of smooth centroid finite-difference estimators for the task. The attained results prove the effectiveness of the studied methods of measuring the time delay difference in practice. The studied algorithms may be implemented on the base of modern microcontrollers with relatively low computation complexity, being statistically effective within the considered task. The results of the work prove the advantages of the proposed approach for the ultrasonic clamp-on flow measurements

Euler configurations and quasi-polynomial systems

In the Newtonian 3-body problem, for any choice of the three masses, there are exactly three Euler configurations (also known as the three Euler points). In Helmholtz' problem of 3 point vortices in the plane, there are at most three collinear relative equilibria. The "at most three" part is common to both statements, but the respective arguments for it are usually so different that one could think of a casual coincidence. By proving a statement on a quasi-polynomial system, we show that the "at most three" holds in a general context which includes both cases. We indicate some hard conjectures about the configurations of relative equilibrium and suggest they could be attacked within the quasi-polynomial framework.Comment: 21 pages, 6 figure

IMPLEMENTATION OF A HIGH-EFFICIENT ELEMENTARY HEATER IN THE CIRCUIT OF AN EXISTING EVAPORATOR WITH THE PURPOSE OF SAVING HEATING STEAM

he paper gives a brief description of the method for producing alumina (Al2O3) by the Bayer method.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)