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Earlier, a method for constructing an initial approximation for solving the inverse problem of acoustics by a gradient method based on a convolutional neural network trained to predict the distribution of velocities in a medium from wave response was proposed [9]. It was shown that the neural network trained on responses from simple layered media can be successfully used for solving the inverse problem for a significantly more complex model. In this paper, we present algorithms for processing data about epidemics and an example of applying a neural network for modeling the propagation of COVID-19 in Novosibirsk region (Russia) based only on data. A neural network NN-COVID-19 that uses data about the epidemics is constructed. It is shown that this neural network predicts the propagation of COVID-19 for five days by an order of magnitude better than SEIR-HCD. When a new variant (Omicron) appeared, this neural network was able to predict (after retraining) the propagation of the epidemics more accurately. Note that the proposed neural network uses not only epidemiological data but also social ones (such as holidays, restrictive measures, etc.). The proposed approach makes it possible to refine mathematical models. A comparison of the curves constructed by SEIR-HCD model and by the neural network shows that the plots of solutions of the direct problem almost coincide with the plots constructed by the neural network. This helps refine coefficients of the differential model. [ABSTRACT FROM AUTHOR]

The optical scheme and technical characteristics of terahertz planar Michelson interferometer based on surface plasmons are presented. A technique for determination of the complex index of refraction of surface plasmons () from interferograms is described. The paper presents the results of test measurements on flat surfaces with gold sputtering coated by ZnS layers 0 to 3 μm thick with application of the high-power coherent radiation from the Novosibirsk free electron laser at the wavelength λ0 = 141 μm. From the measurement results, the value of the effective permittivity of the sputtered gold surface was found, which turned out to be an order of magnitude lower than that of crystalline gold. Analysis of the energy losses in the plasmonic interferometer made it possible to estimate its dynamic range (106–108 in terms of radiation power) required for measurements on samples with different . Ways to increase the signal-to-noise ratio via optimization of the elements of the optical scheme and detector have also been proposed. [ABSTRACT FROM AUTHOR]

This paper is a tribute to an internationally renowned scientist, Prof. Fedor A. Kuznetsov with several noteworthy contributions to his credit. He had played a key role in strengthening Indo-Russian collaboration in science and technology. The author had the privilege of actively pursuing several joint R&D projects. My laboratory had received an advanced Crystal Growth system developed at the Institute of Inorganic Chemistry, Novosibirsk. Several scientists of this institute had been our guests and published jointly authored research papers. Some results of important investigations carried out in author′s group are described. [ABSTRACT FROM AUTHOR]

This paper considers the use of radar and optical data from the Sentinel 1 and Sentinel 2 satellites for 2019–2020 to assess the humus content and the percentage of clay and moisture in the topsoil using the example of chernozems and gray forest soils of the Novosibirsk oblast. Particular attention is paid to the selection of satellite images, because in order to quantify the humus content and clay in the soil, it is necessary to fulfill the conditions for the soil to be dry and bare. The humus content is estimated for five test sites based on a regression model (Karavanova and Orlov, 1996), which includes surface reflection coefficients at the wavelength of the B6 spectral channel of the Sentinel 2 satellite. The model parameters are adjusted for the conditions of the study area separately for chernozems and gray forest soils. The percentage of physical clay in the soil is estimated using Sentinel 2 optical data, ground measurements, and regression models with an exponential dependence of clay content on soil reflectances at the SWIR wavelengths of the Sentinel 2 spectral channels (Bousbih et al., 2019; Shabou et al., 2015). The change in the percentage of humus and clay content in the test sites of soils over the year is shown according to Sentinel 2 data. The topsoil moisture content is estimated based on radar, optical, and the combined use of radar and optical data. [ABSTRACT FROM AUTHOR]

In this paper, an analytical theory for the diffraction of a Bessel beam of arbitrary order Jl(κr) on a 2D amplitude grating is presented. The diffraction pattern behind the grating turned out to be more complicated in comparison with the classical Talbot effect observed under illumination by a plane wave. In particular, the patterns in the main and fractional Talbot planes under certain conditions that are found in the article, are lattices of ring microbeams, the diameters of which depend on the period of the grating, the diameter of the illuminating beam, the number of the Talbot plane, and the topological charge l. For the rings near the optical axis, the latter reproduces l of the illuminating beam. The diffraction patterns observed in experiments on the Novosibirsk free electron laser behind gratings with periods of 1 to 6 mm, illuminated by zero- to second-order Bessel beams at a radiation wavelength λ = 141 µm, are in good agreement with both theoretical predictions and numerical calculations. We emphasize that an analytical theory based on the scalar theory of diffraction perfectly describes resulting diffraction patterns with hole diameters down to 0.25 mm, which are less than 2λ, when, formally speaking, the scalar theory becomes incorrect. Since the Laguerre–Gaussian beams can be represented as a superposition of Bessel beams, results of this paper can be applied to analysis of the Talbot effect with the Laguerre–Gaussian beams. A regular lattice of ring-like vortex microbeams, which can be formed in the Talbot planes, can be applied, for example, to creation of a lattice of optical traps, transmission of orbital angular momentum to elements of micromechanical devices, and to launching surface plasmon polaritons on an array of metal wires by 'the end-fire coupling technique'. [ABSTRACT FROM AUTHOR]

In this paper, we describe the project of a photon source with energies up to 2500 MeV at the SKIF synchrotron radiation facility (under construction in Novosibirsk). It is intended for experiments on photonuclear reactions, nonlinear QED, EM detector calibration and other applications. A polarized photon beam with a flux of 106–108 Hz (in full spectrum) is produced using Compton backscattering (or inverse scattering) of IR, visible, and UV laser radiation, as well as the UV band of its own synchrotron radiation, on the SKIF electron beam (15 kHz). Spectrum monochromatization with collimators or/and tagging system by recoil electrons is possible. The discrepancy between experimental and theoretical photofission cross sections of actinide nuclei in a photon energy range of hundreds of MeV has been known since the 1980s, so it is proposed to study these cross sections in the first series of experiments. [ABSTRACT FROM AUTHOR]

This paper reports the results of satellite image and seismological data analysis obtained when considering the causes of a landslide on the Yelbashinskii dump at the Kolyvan anthracite deposit. The potential for determining the natural vibrations of large objects from low-frequency seismological records and monitoring thereof has been demonstrated. [ABSTRACT FROM AUTHOR]

A graph G is (d 1 , d 2 , ... , d k) -colorable if the vertex set of G can be partitioned into subsets V 1 , V 2 , ... , V k such that the subgraph G [ V i ] induced by V i has maximum degree at most d i for i = 1 , 2 , ... , k . Novosibirsk's Conjecture (Sib lektron Mat Izv 3:428–440, 2006) says that every planar graph without 3-cycles adjacent to cycles of length 3 or 5 is 3-colorable. Borodin et al. (Discrete Math 310: 167–173, 2010) asked whether every planar graph without adjacent cycles of length at most 5 is 3-colorable. Cohen-Addad et al. (J Comb Theory Ser B 122:452–456, 2017) gave a negative answer to both Novosibirsk's conjecture and Borodin et al.'s problem. Zhang et al. (Discrete Math 339:3032–3042, 2016) asked whether every planar graph without adjacent cycles of length at most 5 is (1, 0, 0)-colorable. In this paper, we show that every planar graph without adjacent cycles of length at most five is (2, 0, 0)-colorable, which improves the result of Chen et al. (Discrete Math 339:886–905, 2016) who proved that every planar graph without cycles of length 4 and 5 is (2, 0, 0)-colorable. [ABSTRACT FROM AUTHOR]

Siberian Federal District (SFD) is located in the center of the Russian Federation, occupying 30% of its territory. Its population is 19,326 thousand people, which constitutes 13.2% of Russia's total population. The district consists of 12 constituent entities, which, to one degree or another, are engaged in agricultural production. Grain crops are grown in each of the SFD regions, with the way being currently led by Altai Krai, Krasnoyarsk Krai, Omsk Oblast, Kemerovo Oblast, and Novosibirsk Oblast, which account for 90% of the district's gross grain output. Most of the district's land under cultivation is sown to wheat (67%). However, due to unstable and low prices for wheat, agriproducers are forced to consider dropping some of the traditional crops and shifting, in accordance with the changing needs of the market, to other - sought-after and more competitive - grain crops. Another major issue in grain production within the district is the relatively low quality of grain, which diminishes its competitiveness in the market, with nearly 60% of all grain being represented by low-protein feeding grain. It may, therefore, be advantageous for Siberian agriculturists to grow grain for livestock farming, and this may require enhancing the actual structure of the land under cultivation and focusing on growing grain crops with the protein component greater than in the 4th class soft wheat. The paper shares some of the findings from an assessment of the region's agro-climatic potential for the period through to 2025. [ABSTRACT FROM AUTHOR]

This review paper describes some major contributions provided by European scientists to the development of CFD from the early 70s to the end of the 20th century. Particular attention has been paid to those authors who have contributed to the success of the ICNMFD, started in 1969 (Novosibirsk) from a joint effort of scientists involved in the space race in the USA and the USSR，and of the ISCFD，started in 1995 (Tokyo) as a Pacific competitor to the ICNMFD. These two very important biennial international conferences have then merged into the ICCFD，starting from the year 2000，thanks to the efforts of the two scientific committees, promoted by prof. Oshima and the author. The majority of the authors whose work is the subject of this paper have been members of one or more of the Scientific Committees of the three aforementioned conferences, usually after having been selected to provide invited lectures to the same. Their choice is the sole responsibility of the author and is certainly incomplete and biased towards more applied, rather than theoretical CFD. Also，they are often personal friends of the author who has been a member of the CFD community for 40 years. Thus, this paper does not consider younger scientists, independently of the value of their contributions. Moreover，it is noteworthy that European CFD has always been strictly interconnected with US CFD. Some of the authors have started their careers in Europe and are now living and working in the USA (e. g., Glowinski，Roe, Van Leer)； others have obtained their Ph. D. in the USA (e. g., Launder, Napolitano), and all of them have worked together with US scientists, so that it is difficult to distinguish between European and US CFD. For those who moved to the USA, their contributions prior to their move have been favored Last but not least，each of the authors discussed in this work has been asked~by an e-mail that I hope reached them--to write a draft of his own chapter so as to provide the most authoritative review of his contributions. Those who have done so have been duly acknowledged The other ones will have to forgive the author for an inadequate description of their merits. [ABSTRACT FROM AUTHOR]

This Virtual Special Issue includes six peer-reviewed papers, which were selected from the plenary lectures, keynote lectures and conference papers at the 5th International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control (IWHT2019) in Novosibirsk, Russia on August 13–16, 2019. The topics of these papers mainly focus on the heat and mass transfer in energy, power and industrial process systems, including heat exchanger used for floating liquefied natural gas, methane hydrate reservoir, supercritical carbon dioxide Brayton cycle, proton exchange membrane fuel cell, and distillation columns with structured packing. The machine learning methods used for nanofluid research in renewable and sustainable energy systems were also discussed. The studies in this special issue will inform the development of energy conservation and pollution control technologies, which is the purpose of IWHT, and will also support the global decarbonisation of heat and mass transfer systems. • Six peer-reviewed papers were selected from IWHT2019. • The heat/mass transfer in energy, power and industrial process systems are focused. • It will support the global decarbonisation of heat and mass transfer systems. [ABSTRACT FROM AUTHOR]

The famous Steinberg's conjecture states that planar graphs without cycles of lengths 4 and 5 are (0 , 0 , 0) -colorable. Recently, Cohen-Addad et al. [6] demonstrated that Steinberg's conjecture is false by constructing a counterexample. Let F denote the family of planar graphs without 3-cycles adjacent to cycles of lengths 3 and 5. Borodin et al. posed the Novosibirsk 3-color conjecture, which is the statement that every graph in F is (0 , 0 , 0) -colorable. It is easy to observe that the counterexample of Cohen-Addad et al. shows also that if G ∈ F , then G is not always (0 , 0 , 0) -colorable. Motivated by this observation, this paper proves that every member G ∈ F is (1 , 1 , 0) -colorable, which is a positive step. [ABSTRACT FROM AUTHOR]

Higher output of competitive and high-quality agricultural products implies the more efficient use of the resource potential held by agricultural organizations. In the modern conditions, it is essential to substantiate indicators and conditions in order to improve the efficiency of the resource potential and to determine resource potential needs for the manufacture of agricultural products. The agroindustrial complex resource system aims to improve the efficiency of its use. The entry into the resource potential system includes the attraction of main production factors (labor, land, capital, entrepreneurship). The resource potential system is used as a subsystem of a region’s economic potential. The exit from the system constitutes the more efficient use of the resource potential. The exit from the resource potential system is the entry into the production potential system with a view to manufacturing agricultural products. An agricultural organization’s resource potential is a transparent production system, in which entrepreneurship, taking into account the prevailing market conditions, the modern development level of production forces and production relations, unites, in an optimal combination, in an organization of the relevant organizational-legal form and puts into action technologically dependent factors of agricultural production (labor, land, capital). In the article, the authors substantiate conditions and targets for the efficient use of the resource potential. Taking into account innovative development and achievements of leading companies, resource needs for grain and milk output have been determined. [ABSTRACT FROM AUTHOR]

Tremendous progress has been achieved in the last ten years with respect to modeling the combustion of solid propellants. The vastly increased performance of computing capabilities has allowed utilization of calculation approaches that were previously only conceptual. The paper will discuss three areas of emphasis: first, numerical modeling of premixed flames using detailed kinetic mechanisms; second, development of packing models to calculate a geometrical distribution of particles simulating a heterogeneous solid propellant; and finally, calculation of diffusion same effects that are critical in the combustion of AP/hydrocarbon solid propellants. The capability of modeling premixed combustion using detailed kinetic mechanisms has been evolving and successfully applied to solid propellant ingredients based on a one-dimensional approach. Much of the early work was performed at Novosibirsk. The approach allows calculating the burning rate as a function of pressure but also the temperature sensitivity and spatial distributions of temperature and species concentrations. Generalized mechanisms have been developed and applied to many ingredients such as HMX, GAP, RDX, NG, AP, etc. The gas-phase kinetic mechanisms seem to represent the chemistry of these monopropellants and pseudo-propellants consistently well. The burning rates of these monopropellants vary by almost an order of magnitude but are essentially independent of the flame temperature. Various model calculations agree reasonably well with available experimental data. Recent work in the USA has been aimed at describing the geometrical packing of a solid propellant. These models represent significant progress toward such a description. Combining the packing model with a realistic flame model is still a significant challenge. Preliminary results are encouraging, but obviously further work is needed. Also, fundamental calculation of two-dimensional diffusion flames, incorporating realistic kinetics has progressed significantly. Recent results show encouraging promise toward simulating the minute detail involved in determining the burning rates of AP containing propellants. [ABSTRACT FROM AUTHOR]

The paper summarizes the ninth annual conference of the Russian Library Association in May 2004. Included are the exhibits, several plenary addresses, the work of the Bibliography Section, and election results. [ABSTRACT FROM AUTHOR]

The ramp-up of the agricultural industry output requires the use of new, high-performance machines, whilst the complicated world economic situation has made it difficult to purchase foreign agricultural equipment. All these factors contributed to an increase in the demand for both domestic and Belarusian equipment. Tractors and various attachments are the most popular type of farm machinery with agricultural producers, which is used in almost all farm works. In this regard, there is a significant load being placed on them which leads to frequent breakdowns. At the same time, the age of tractors in farms of the Novosibirsk Region is mostly more than 10 years, which is also one of the reasons for failing. Most farms are simply unable to regularly update their machine and tractor fleet; therefore, during the spring field works or crop harvesting, it often happens that machines break down and wait for repairs for a long time. This results in crop losses and low yields. It is necessary to develop such a mechanism of the material support for agricultural producers which will help to avoid equipment downtime and lead to an increase in the gross collection. [ABSTRACT FROM AUTHOR]

The Super Charm–Tau (SCT) Factory is a proposed electron–positron collider in Novosibirsk with a peak luminosity of 1 0 35 cm − 1 s − 1 operating in the energy range between 2and 6 GeV. The interaction region should be equipped by an excellent universal particle detector meeting the requirements of broad physics program of the experiment. Research and development for all detector subsystems is currently underway. Particle identification (PID) system of the detector is required to provide the state-of-the-art level of μ / π separation for the particle momenta up to 1. 2 GeV∕c. The following options for the PID system are considered in this paper: focusing aerogel ring imaging Cherenkov (FARICH) detector composed of 4-layer aerogel tiles, threshold Cherenkov counters based on aerogel shifter photomultiplier (ASHIPH), and time-of-flight (ToF) detector combined with the time-of-propagation (ToP) approach providing a time resolution better than 30 ps. Assessment of the charged particle separation performance for these options based on simulation and prototype tests results is presented. [ABSTRACT FROM AUTHOR]