bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invariant manifold of variable stability in the Koper model
Authors: Balabaev M 
Published: November 2019

Abstract
The Koper model is a vector field that was developed to study electrochemical oscillations arising in diffusion processes. In the framework of this paper, we consider the Koper model of chemical reactors. It is a three-dimensional autonomous slow-fast system with a folded node and a supercritical singular Hopf bifurcation. The aim is to construct the expansion of invariant manifold with variable stability and corresponding gluing function using the flow curvature method. We show that Koper model has sufficiently smooth invariant surface, called black swan. Computer simulation and computer algebra methods are used for the quantitative analysis of the model.
Numerical simulation of the catalytic process of isomerization of pentane-hexane cut
Authors: Faskhutdinov A G , Faskhutdinova R I , Arefyev I A , Enikeeva L V 
Published: November 2019

Abstract
The basic schemes for the transformation of the pentane-hexane fraction catalytic isomerization, which are probable from the point of view of thermodynamics, have been considered. Based on the literary analysis of possible transformation schemes, the mechanism of the process and on the basis of experimental data, a mathematical model of the reactor block of the process was constructed and the kinetic parameters were determined. The foundations were laid for the subsequent solution of the tasks of the multi-purpose optimization of the catalytic isomerization process of the pentane-hexane fraction.
Strategy for the realization of soft docking with space debris by using a tether system
Authors: Pikalov R S 
Published: November 2019

Abstract
This study focuses on the dynamics of a rendezvous of a tug and large space debris connected by a viscoelastic tether. It is assumed that control is realized by changing the length of the tether. The goal is to study the dynamic of the maneuver of the rendezvous and to find the ways, which allow one to reduce the oscillation of the tether. The obtained results can be applied as applications for the tasks of implement rendezvous of two bodies using the tether.
Positioning of radio emission sources with unmanned aerial vehicles using TDOA-AOA measurement processing
Authors: Bachevsky S V , Fokin G A , Simonov A N , Sevidov V V 
Published: November 2019

Abstract
Positioning of radio emission sources (RES) with ground and flying network segments exploits interaction of sensors aboard Unmanned Aerial Vehicles (UAVs) with terrestrial stationary ground sensors. Time Difference of Arrival (TDOA) and Angle of Arrival (AOA) measurements processing are the most wide-spread techniques for passive geolocation systems. Successful implementation of TDOA-AOA positioning in existing UAV based geolocation systems achieves accuracy results of tens and hundreds of meters for overoptimistic scenarios without reflections in so called Line of Sight (LOS) conditions. Prevailing application specific cases for UAV based positioning include search and rescue (S&R) operations in mountains, hills and other regions of irregular surface topography with Non-Line of Sight (NLOS) conditions, where radio waves could experience severe reflection and diffraction. For geolocation tasks NLOS problem usually leads to significant errors for both TDOA and AOA measurement processing techniques. Joint processing of TDOA and AOA primary measurements could partially overcome this problem by preliminary identification and exclusion of reflected signals. In current research we refine existing mathematical model and develop new simulation models to investigate NLOS tolerance during positioning with one stationary ground sensor and one sensor aboard flying UAV using joint TDOA-AOA measurement processing technique. The contribution of current research is performance evaluation of considered positioning system with AOA noise and confirmation of its practicability to handle NLOS problem, when AOA deviation is less than 10 degrees.
Improving the efficiency of multichannel systems based on the coordination of channel signals
Authors: Voronkov G S , Filatov P E , Sultanov A Kh , Kutluyarov R V , Vinogradova I L , Kuznetsov I V 
Published: November 2019

Abstract
A method for improving the energy efficiency and noise immunity of multichannel systems, based on the overall coordination of channel signals, is described. To coordinate the signals, a coordinating matrix is used, whose elements are the cross-correlation coefficients of signals from different channels. The possibility of reducing the dynamic range of channel signals while maintaining the quality of communication is shown. The possibility of synthesizing invariant (with an unlimited transfer ratio in separate channels) of coordinated group DPCM codecs with channels of the same type is shown.
How to read the trendless sequences: the “universal” set of quantitative parameters
Authors: Nigmatullin R R , Vorobev A S 
Published: November 2019

Abstract
In this paper it is demonstrated a new set of “universal” parameters that help to read quantitatively any trendless sequence (TLS). This method is applied for solving the problem of selection of the “pattern” noise from the tested one and for calibration of random fluctuations expressing some qualitative inputs in terms of these quantitative parameters. This set of quantitative parameters allows to compare the TLS(s) of different nature (acoustic, mechanical, electrochemical, vibrational and etc.) with each other. Using the proposed algorithm, we analysed the differences between software simulated and experimentally generated white noises. We do suppose that the proposed “universal” scheme free from uncontrollable errors can find a wide application in solution of many practical problems.
Modeling the effect of temperature deformations of large elements on the dynamics of the orbital motion of a small spacecraft
Authors: Sedelnikov A V , Rodina V S , Orlov D I 
Published: November 2019

Abstract
The effect of temperature deformations of panels of solar battery of a small spacecraft like “Aist–2D” is modeling in this paper. Temperature deformations occur while a small spacecraft enters and goes into the shadow of the Earth. The effect of temperature deformations on the dynamics of the orbital motion of a small spacecraft is reviewed. Conclusions are made regarding the consideration of temperature deformations for efficient operation of orbital motion control system. The tree-dimensional heat conduction problem was solved during the modeling. Computational modeling was made by the LS-Dyna package. The results of work may be used while creating a small spacecraft with large elastic elements control laws and the shadow segment of the orbit.
Mathematical models of operating regimes of flood control facility’s system
Authors: Antonov V I , Davydov R V , Maslikov V I , Molodtsov D V , Chusov A N 
Published: November 2019

Abstract
The rapid spread of storm floods over large areas requires flood management throughout the river basin by the creation of a system of flood control facilities of various functional purposes distributed in the area. The central part of the system is the hydro system with a hydroelectric power plant. Also, the flood control facilities on the side tributaries with the self-regulating reservoir are included in it. The development of mathematical models is needed to ensure the effectiveness of using flood control facilities, reflecting the specifics of their operation. We have developed unified mathematical models of a hydraulic structure with a hydroelectric power station and a means of protection against floods. These models are implemented in a computer program that provides the ability to determine the main parameters and operating regimes of hydro systems in a wide range of initial data. It makes possible specifying the parameters and operation modes of each hydro system with the current economic and environmental requirements, to assess the energy-economic and ecological consequences in the work of the flood control facilities distributed in the area.
Monte Carlo modelling of normal skin and skin cancer Raman spectra
Authors: Matveeva I , Myakinin O 
Published: November 2019

Abstract
In this paper, we propose an algorithm of Monte Carlo modelling of Raman scattering. A model of Raman scattering in multi-layered tissues has been built. A number and optical properties of tissue layers, number of photons, geometric size of the model and parameters of the light source may be varied by users. Some of computational results have been compared with other investigators.
Clustering based on the principle of finding centers and robust averaging functions of aggregation
Authors: Shibzukhov Z M , Kazakov M A 
Published: November 2019

Abstract
A new approach to robust clustering based on the search for cluster centers is proposed. It is based on minimizing the robust estimates of the averages and the sum of the functions of pseudo-distances to cluster centers. An algorithm of iterative reweighing type for finding cluster centres is proposed. Examples are given showing the stability of the method with respect to a large number of outliers.
Intelligent integrity monitoring system for technological process data
Authors: Arpishkin M I , Vulfin A M , Vasilyev V I , Nikonov A V 
Published: November 2019

Abstract
The relevance of the work is due to the widespread use of network telecommunications in the automated process control system and the high level of danger of replacing, distorting or losing accumulated data on the process progress as a result of the attacker’s influence. Objective: increasing the security of measurement results from unauthorized modification in the databases of information systems of an industrial enterprise by improving process monitoring system based on the intellectual analysis of technological time series. A structural scheme of process monitoring as part of an information protection system in a segment of an automated process control system network has been developed. The algorithm of intellectual analysis of technological time series in the task of detecting violation of the integrity of data on the process progress due to their unauthorized modification was proposed. Evaluated the effectiveness of the proposed solution on field data. Keywords: Monitoring of the technological process, analysis of technological time series, integrity of accumulated telemetry data, neural network model of adaptive segmentation, clustering of technological events.
Application of principal component analysis to identify semantic differences and estimate relative positioning of network communities in the study of social networks content
Authors: Rytsarev I A , Paringer R A , Kupriyanov A V , Kirsh D V 
Published: November 2019

Abstract
In the paper, we propose an approach to the analysis of social groups and their relative positioning based on the identification of semantic differences in texts presented in the form of frequency dictionaries. The initial textual data was obtained by collecting records of thematic Internet communities. To collect entries, we implemented a specialized software module for downloading and analyzing posts as well as comments from open communities of interest in the social network VKontakte. The developed algorithm of frequency dictionary compilation evaluates the characteristics of data collected from social networks. For keywords identification, we propose a new approach based on the analysis of word frequency distribution, using methods for dimension reduction of feature spaces. The presented algorithm using the principal component analysis allowed to assess the significance of words by coefficients of the linear transformation. Along with the keywords, we identified semantic differences of social network communities and estimated their relative positioning in the transformed feature space.
Modification of single-purpose CNN for creating multi-purpose CNN
Authors: Shustanov A V , Yakimov P Y 
Published: November 2019

Abstract
Modern traditional convolutional neural networks (CNN) are built to solve one specific task, which can be: detecting and localizing objects in an image, restoring a human skeletal model, classifying images, etc. However, existing business problems can be a combination of the above subtasks. The simplest way to solve this problem is to use several ready-made CNN models or to train such models, one for each subtask. But this approach leads to a strong increase in the required computing power, which can be economically costly. The approach presented in the article allows reducing computational costs by adding new blocks to the existing CNN and creating a multi-purpose model.
Surface roughness estimation by using a 3D model reconstructed from multiple images
Authors: Viktorenkov A E , Yakimov P U 
Published: November 2019

Abstract
In this paper, the roughness parameters of the part are estimated based on its reconstructed 3D model. Reconstruction of the 3D model was carried out using the structure from motion photogrammetry method. Preliminary processing of the 3D model consisted in fitting the plane to the point cloud of the 3D model using the least squares method, aligning and scaling the 3D model. Also, the resulting 3D model was approximated using the radially basic functions to obtain a uniform cloud of points. Next, the obtained point cloud was filtered to identify 2D and 3D roughness profiles. As filters, a Gaussian filter and 2RC were used. The roughness parameters of the obtained profiles were calculated. A comparison of the roughness parameters calculated on the basis of the 3D model and the roughness parameters calculated by the BV-7669 profilometer was made.
The diffusion-tensor MRI data analysis for cerebral microangiopathy influence detection on the integrity of the brain white matter in Alzheimer’s disease patients
Authors: Gridin V N , Perepelov V A , Solodovnikov V I , Yakhno N N 
Published: November 2019

Abstract
The analysis of diffusion-tensor magnetic resonance tomography data is carried out to assess the contribution of cerebrovascular disease to the violation of the microstructural integrity of the brain white matter in Alzheimer’s patients. The values of DTI (Diffusion Tensor Imaging) indicators are studied for 19 regions of the brain. The issues of data pre-processing, their analysis by statistical and neural network methods, including visualization using Kohonen self-organizing maps, are considered. It provided a number of anatomical structures of the brain that have the greatest specificity in Alzheimer’s disease combined with cerebral microangiopathy in contrast to isolated Alzheimer’s disease. This approach provides important diagnostic information about the involvement of various brain areas in the pathological process.
Flow and heat transfer characters in the integral internal cooling channel of a turbine blade
Authors: Guo Tao , Zhu Huiren , Zhou Zhixiang 
Published: November 2019

Abstract
A scaled model of the integral internal cooling channel of a turbine blade was established for the experimental investigation. The model was made by Perspex for its transparency so that the thermochromic liquid crystal measurement could be used easily. The cooling channel is composed of 3 legs of ribbed channels. Rib with angle 45° was settled in both pressure side and suction side, which forms a cross-rib structure. Three legs were connected by two 180° turns. The main inlet and two addition inlets were arranged in the root of the model channel. Two discharge outlets were located in the tip. A row of outlet holes was distributed along the trailing edge. The channel area gradually decreases along the blade height direction, while bending and torsion occur because of the blade airfoil shape. The aspect shapes and connection methods of the channel were kept in accordance with the real blade. The inlet Reynolds number is from 10000 to 32000. Five outlet discharge ratios were alternated in this investigation. The detailed heat transfer distributions, both in the pressure side and suction side, were measured by transient liquid crystal technic. The characters of heat transfer distribution and pressure drop along the channel were displayed. The effects of flow discharge ratio on heat transfer and pressure coefficient were also described.
Heat transfer at evaporation/boiling in the thin horizontal liquid layer on microstructured surfaces under low pressures
Authors: Zhukov V. I. , Pavlenko A. N. , Bessmeltsev V. P. 
Published: November 2019

Abstract
The results of the experimental study of heat transfer during boiling of n-dodecane on a capillary-porous surface are presented. The surface is coated using a 3D laser printer. The dependence of the heat transfer coefficient on the heat flux density under different pressures and liquid layer heights is studied. The obtained experimental data were compared with the values obtained during evaporation/boiling on a plain surface under the same conditions.
Comparative analysis of heat supply options for small and middle-sized settlements of Eastern Siberia by using uncertain and fuzzy information
Authors: Khan V V , Dekanova N P , Khan P V 
Published: November 2019

Abstract
The problems of heat supply in small and medium-sized settlements of Eastern Siberia are considered. Variants of using cogeneration heat plant (CHP) or boiler plant on coal or wood waste, the use of liquid petroleum gas (LPG) and liquid natural gas (LNG) as a fuel, the use of electric boiler plant or stand-alone electric boilers, applications of solar collectors and heat pump installations are considered based on a systems approach and fuzzy modelling, by taking into account the uncertainty of some factors.
An analytical model of subcritical and critical vapor-liquid flow through a granular bed
Authors: Tairov E A , Khan P V 
Published: November 2019

Abstract
This paper presents a computational and experimental justification of a theoretical model for the two-phase vapor-liquid flow through a fixed bed of solid particles. The theoretical description is based on the equations of gas dynamics of the granular bed and the homogeneous model of a single-component two-phase flow, given the difference between the velocities of liquid and vapor phases. Relationships between the phase slip ratio and polytropic coefficient of isenthalpic expansion of vapor-liquid flow were obtained using the multi-parameter nonlinear regression. We used the experimental data on the vapor-liquid flow with an inlet pressure, P
1, of 0.6-1.2 MPa and an inlet flow quality, x
1, of 0.016-0.178 through a H=50-355 mm bed consisting of steel spheres, 2 and 4 mm in diameter, d. An expression for the critical pressure ratio in the granular bed is proposed. The developed model makes it possible to predict the values of mass velocity of the mixture over the entire range of experimental data with an average error of 3%. Based on the model equations, we obtained expressions for dimensionless mass velocity depending on the pressure ratio that can be applied to two-phase flows through both granular beds and other porous media.
Optimization of phase change material component and its application in buildings
Authors: Wang M Y , Cui H Z , Liu Y , Bao J Y , Yang L 
Published: November 2019

Abstract
Improving the thermal transfer performance of phase change material (PCM) component has attracted more and more attention in building the energy-saving field. This paper presented an optimized PCM component which is encapsulated in a metal container, to promote the thermal performance of the wall. Thermal transfer of PCM component is optimized by adding internal fin through numerical simulation software COMSOL Multiphsics. The simulation model was verified by data from publicly available published literature. The temperature difference of PCM component in front and back heating surface (ΔT
s) was employed to obtain the optimal geometric parameters including spacing (S
fin) and length (L
fin) of the fin. Thermal performance of the wall with the optimized and non-optimized PCM component was compared under the summer typical climate. The wall with optimized PCM component has the best capacity for heat storage and release. The interior surface temperature reduction of the wall with optimized PCM component is lower by 2.1 ºC than reference wall.
Influence of the coal-derived synthesis gas composition on the thermal stability of ZnO sorbents in the desulfurization process
Authors: Kagramanov Yu A , Ryzhkov A F , Tuponogov V G , Nikitin A D 
Published: November 2019

Abstract
The priority direction of thermal energy on solid fuels is to increase efficiency and environmental safety, approaching zero emissions of harmful substances. To achieve these goals, they are currently creating new schemes for combined cycle gas turbine units with intra-cycle gasification (IGCC). To improve the efficiency of the IGCC cycle, hot dry desulfurization (HGC) technologies are being developed. HGC uses regenerable sorbents that allow the repeated adsorption of hydrogen sulfide from synthesis gas, among which the most acceptable thermodynamic and operational characteristics are based on ZnO sorbents. The article uses the method of thermogravimetric analysis (TGA) to investigate the development of target reaction capture hydrogen sulfide ZnO-containing sorbent and sorbent reactions with components of synthesis gas in the temperature range up to 1000°C. The sorbent calcined at 900°C shows thermal stability in an inert atmosphere over the entire temperature range studied. Uncalcined sorbents at temperatures of 200 and 600°C emit carbon dioxide in an amount of 1.5-4.5% by weight of the sorbent. At temperatures up to 550°C, the target reaction is basic, and side reactions practically do not develop. The maximum rate of absorption of hydrogen sulfide by the sorbent is observed at a temperature of 600°C. At 500-550°C reactions of a sorbent begin with H2 and CO, at 750-800°C – with carbon, at 850°C – with CH4. The intensity of effect of reagents is defined on degradation of a sorbent by reactionary ability of gases more than temperature.
Investigating the gas-droplet flow generated by a pneumatic nozzle for a coal-water slurry
Authors: Anufriev I S , Kopyev E P , Maltsev L I , Yu Shadrin E , Sharypov O V 
Published: November 2019

Abstract
The paper studies a promising method of spraying, based on the interaction of cumulative and near-wall jets with the impinging liquid and the Coanda effect. The measurements are based on shadow photography (SP) and interferometric method (IPI). In a wide range of performance parameters data have been obtained on the disperse composition of a gas-droplet flow at water spray by a special pneumatic atomizer intended for coal-water fuel. The dependences of droplet sizes on the flow rate of liquid and spraying air have been found.
Investigating substandard liquid hydrocarbons spraying by a steam jet
Authors: Anufriev I S , Kopyev E P , Mukhina M A , Osintsev Ya A , Yu Shadrin E 
Published: November 2019

Abstract
Using the shadow photography (SP) method and the interferometric method (IPI), a two-phase gas-droplet flow was experimentally investigated when the spent transmission oil was sprayed by a jet of superheated steam. In a wide range of operating parameters, data on the dispersed composition of the steam-fuel jet have been obtained. The dependences of droplet sizes in the flow on the studied regime parameters have been established.