148 research outputs found

    Emergent Calabi-Yau Geometry

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    We show how the smooth geometry of Calabi-Yau manifolds emerges from the thermodynamic limit of the statistical mechanical model of crystal melting defined in our previous paper arXiv:0811.2801. In particular, the thermodynamic partition function of molten crystals is shown to be equal to the classical limit of the partition function of the topological string theory by relating the Ronkin function of the characteristic polynomial of the crystal melting model to the holomorphic 3-form on the corresponding Calabi-Yau manifold.Comment: 4 pages; v2: revised discussion on wall crossing; v3: typos corrected, published versio

    Computer vision system for the automatic asbestos content control in stones

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    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

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    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

    Повышение эффективности статистического подхода к обработке данных контроля технологического процесса транспорта нефти

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    Тема научной работы выбрана согласно стратегии совместного сотрудничества РФ и КНР, в которой возрастают требования к эффективности использования нефтетранспортных предприятий. Целью данной дипломной работы является изучение котроля техгологического процесса во времени на примере транспорта жидкости, при помощи метода контрольных карт Шухарта, метод главных компонент и стандарт статистика. В данной работе был произведен расчет и рассмотрена возможность осуществления технологического контроля при мониторинге многопараметрового процесса транспорта жидкости по трубопроводу.The theme of the scientific work is selected according to the strategy of joint cooperation between the Russian Federation and the PRC, in which the requirements to the effectiveness of the use of oil transportation enterprises are increasing. The purpose of this thesis is to study the control of the technological process in time using the example of fluid transport, using the method of Shewhart control charts, the method of main components and the standard statistic. In this paper, a calculation was made and the possibility of implementing technological control in monitoring a multi-parameter fluid transport process through a pipeline was considered

    Bochner transforms, perturbations and amoebae of holomorphic almost periodic mappings in tube domains

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    We give an alternative representation of the closure of the Bochner transform of a holomorphic almost periodic mapping in a tube domain. For such mappings we introduce a new notion of amoeba and we show that, for mappings which are regular in the sense of Ronkin, this new notion agrees with Favorov's one. We prove that the amoeba complement of a regular holomorphic almost periodic mapping, defined on Cn and taking its values in Cm+1, is a Henriques m-convex subset of Rn. Finally, we compare some different notions of regularity

    High-resolution phase based method for FMCW short range radars

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    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

    The results of U-Pb SHRIMP-II dating of zircon from granitoids of Talitsky molybdenum-bearing massif (eastern slope of the Middle Urals)

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    Age position and geodynamic conditions of molybdenum metallization and productive granitoids of the Urals formation are very little studied now. This publication contains the results of isotopic dating of granites from Talitsa Cu-Mo-porphyry deposit which should help solve this problem. The timing of formation of the molybdenum-bearing granitoids of Talitsa deposit was determined by applying the U-Pb SHRIMP-II method through zircons (the Center for Isotopic Research of All Russian Geological Research Institute, St.Petersburg). The U-Pb-age has been calculated on 7 (from a total of 11 conduc­ted) measurements with probability of concordanсе 0.996 and MSWD = 0.105 and it is 297.4 ± 2.3 Ma. The results of U-Pb dating are similar to before published Re-Os ages of Talitsa molybdenite deposit: 299.9 ± ± 2.9 Ma and 298.3 ± 1.3 Ma. These data establishes the new unknown before age level of molybdenum metallization. Until recently there has been only data on the Yuzhno-Shameiskoe molybdenum deposit connected with the subalkaline granites of Malyshevo massif which is younger: 277.1 ± 1.1 Ma. According to the received data, the intrusion of investigated granitoids happened practically at the same time as the formation of the wide-spread in the western slope of the Middle Urals intrusive bodies which are accompanied by gold metallization (Verkhisetsky, Shartashsky and others). With such close (practically the same) time of formation the rocks of molybdenum-bearing and gold-bearing massifs significantly differ in petrochemical peculiarities, which probably determines their metallogenetic specialization. Granitoids forming gold-bearing quartz veins on chemical composition are rocks of calc-alkaline series (typical exemple - Shartashskyi massif with Beriozovsk gold deposite). The granitoids productive on of Cu-Mo-porphyry type metallization together with large number of normal alkalinity rocks includes subalkaline rocks such as monzodiorites and quartz monzodiorites

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

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    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)

    DEVELOPMENT OF A HEAT EXCHANGER CONSTRUCTION FOR HEATING ALUMINUM SOLUTION WITH A BATTERY ASSEMBLY

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    The paper outlines the main reasons for the inlay of heat exchange equipment during heating of the aluminate solution. Considered methods of reducing scale formation on heat transfer surfaces. The design of the newly developed heat exchanger is described.В работе изложены основные причины забивки теплообменного оборудования при подогреве алюминатного раствора. Рассмотрены меры для снижения накипевыделения на теплообменных поверхностях. Описано конструктивное исполнение вновь разработанного теплообменника
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