bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application a cubic spline to calculate derivatives in the presence of a boundary layer
Authors: Blatov I A , Zadorin A I 
Published: February 2021

Abstract
The problem of calculating the derivatives of a function with large gradients given at the grid nodes is considered. The decomposition of the function into regular and singular components is assumed. Such decomposition takes place in the presence of an exponential boundary layer. The case of the Bakhvalov mesh is considered. The error in calculating the derivatives based on the differentiation of the interpolating cubic spline is estimated. Error estimates are obtained taking into account uniformity in a small parameter.
Modelling and construction of curriculum optimization algorithms in order to improve the effectiveness of management of the educational process
Authors: Guts A K , Senkovskaya A A , Furayeva I I 
Published: February 2021

Abstract
This article discusses the principles of influence on improving the management of the educational process of a university from the perspective of analysis and optimization of work plans. Mathematical models are presented for optimizing working curricula separately for the first and senior courses, taking into account such factors as the contingent of students, the classroom fund of the university. Different approaches to the analysis of curricula for the first and senior courses are demonstrated. The basic functions of an automated system that implements the formulated models for the analysis of curricula are described.
On Hybrid Evolutionary Algorithms for Scheduling Problem with Tardiness Criterion
Authors: Kovalenko Yu V 
Published: February 2021

Abstract
We present hybrid algorithms based on various metaheuristics for the scheduling problem with one machine and total weighted tardiness criterion. We research operators and algorithmic mechanisms provided in the literature. Advantages and disadvantages of the considered approaches are identified and analyzed. Some of the stated properties are common for scheduling problems on permutations.
Analysis of the influence of the geometry of the input part of the matrix on the formation of the edge part of the cylindrical bill
Authors: Pasynkov A A , Larin S N , Platonov V I 
Published: February 2021

Abstract
The formation of an uneven geometry of the end part of cylindrical products is quite common after the implementation of drawing of sheet blanks. It occurs due to the imbalanced orientation of the crystallographic structure of the material, that is, due to the anisotropy of the mechanical properties. As different elements of the sheet bill have different speed of movement relative to the tool during the drawing, so-called scallops, or protrusions, appear. This causes a problem during the production, since it takes additional time and resources to bring the geometry of the products to the norm. Therefore, the actual task is to minimize this phenomenon. The article discusses an approach to eliminating or minimizing scallop formation by means of scientifically grounded selection of the geometry of the input part of the matrix. The influence of geometry parameters on the uneven geometry of products and their stress state is described.
The methods and approaches to computer networks simulation using virtual network infrastructure
Authors: Podsadnikov A V , Rozov K V , Kratov S V 
Published: February 2021

Abstract
The article is devoted to the problem of computer networks simulation in educational process. The article examines the current state of affairs in this area. The analysis of the existing software for computer networks simulation is performed. The practical example of Cisco Packet Tracer software using for computer network simulation as part of the Computer Networks training course is provided.
A heuristic for a special case of the generalized assignment problem with additional conditions
Authors: Zaozerskaya Lidia 
Published: February 2021

Abstract
We consider the following variant of the generalized assignment problem (GAP). There are a set of agents and a set of jobs for which a single resource use. Each job is to assign to one and only one agent subject to the constraints on the capacity and loading of agents. The resource expense for executing any job is independent of the agents choice unlike the profit from the job. Each job has a certain type (or color). For every agent, the maximum possible number of the job types given. It is necessary to find a feasible assignment of agents to jobs so that all jobs were completed and total profit was maximized. Finding a feasible solution to this problem is NP-hard. We present a heuristic algorithm based on the ideas of random search and local improvement of solutions. Used the mixed-integer programming (MIP) relaxation and variables fixing, we construct a set of integer linear programming (ILP) subproblems similar to the original problem and solve them by the general MIP solver. The results of a computational experiment for tasks with random initial data are presented.
Gesture recognition system based on electromyography signals
Authors: Kabanov A A , Nikonova G V 
Published: February 2021

Abstract
The subject of the study is a gesture recognition system based on an electromyography signal for controlling anthropomorphic prostheses. As a result of the work, signals were received and written to files, software was developed for processing and filtering signals, as well as for recognizing gesture patterns. The resulting system will allow to determine various hand movements based on the electromyography signal and control anthropomorphic prostheses. The resulting system will allow to determine various hand movements based on the electromyography signal and control anthropomorphic prostheses.
Intelligent system functioning for thermophysical measurements in an uncertain measuring situation
Authors: Selivanova Z M , Kurenkov D S , Varepo L G , Trapeznikova O V 
Published: February 2021

Abstract
In the conditions of production under the influence of external and internal factors, the functioning of an intelligent system for thermophysical measurements is associated with the uncertainty of the measuring situation. As a result, the accuracy and efficiency of determining the thermal properties of study subjects – thermal insulation materials - decrease. The study purpose is to achieve the required accuracy and efficiency of the qualitative property parameters of the studied objects in non-destructive control under the uncertainty of the measuring situation, which is important and relevant. A formalized states description of the intelligent system for thermophysical measurements is proposed, taking into account the structure of the system, information and measurement situations, the materials under study, and control signals. The mathematical model has been developed to describe the functioning of an intelligent system under conditions of uncertainty and its application in the operation of the system. An intelligent system of thermophysical measurements with a reconfigurable structure adapting to the measuring situation has been developed. The study results are obtained using the theory of systems, well-known methods of thermal conductivity and methods of artificial intelligence. Experimental results of operating the intelligent system for thermophysical measurements in conditions of uncertainty are presented. They confirm the increase in the accuracy of determining the qualitative properties of the objects under study.
The method of processing data of mass spectrometric analysis of vacuum medium of quartz resonator-thermostats
Authors: Belousov K A , Strunin V I , Khudaibergenov G Zh , Yarosh A M 
Published: February 2021

Abstract
The theoretical and practical development of gas environmental analysis with the usage of a complex based on a residual gas analyzer is briefly presented. The data of technological search of annealing, degassing and sealing modes of quartz resonators and generators with participation of authors are summarized. The gas flow rate was estimated from the mass spectra. The method of measurement of working parameters of products, as well as estimation of operating time resource is proposed. Measurement of quartz resonator-thermostats (QRT) parameters is performed using serial technologies.
Average lifetimes of a metastable state at low barrier in the overdamped regime
Authors: Chushnyakova M V , Gontchar I I 
Published: February 2021

Abstract
Thermal decay of a metastable state is a process revealing itself in particular in the contemporary single-molecule pulling experiments. Unfortunately, some approaches used for the interpretations of these experiments in the literature are incorrect and misleading. We prove this statement in the present work. For this aim, the most important characteristic of the decay process which is the average lifetime of a Brownian particle in a metastable state is considered. For this state two typical potentials are used: the Lennard-Jones and cubic potentials. We concentrate on the case of strong friction (overdamped regime) and low barrier since these conditions are typical for the mentioned experiments. We calculate the average lifetimes using five approaches, including dynamical modeling, and compare them with each other.
Solid solutions of hetero- and homo-substitution of the AIIIBV-CdTe, AIIBVI-CdTe systems. Physical and chemical properties
Authors: Kirovskaya I A , Ekkert A O , Ekkert R V , Chernous N V , Kropotin O V , Kraseninin V I 
Published: February 2021

Abstract
In the regions of mutual solubility of the initial binary compounds (InP and CdTe, ZnS and CdTe), according to the specifically developed methods, solid solutions of the InP-CdTe, ZnS-CdTe systems have been obtained, certified based on the results of X-ray, micro-, submicroscopical, UV, infrared studies as substitutional solid solutions with a cubic sphalerite structure.
Information on the multicomponent diamond-like semiconductors has been supplemented, including first-ever determined values of the average size (dav), the mean number (nav) of the predominant particles in the systems components, their forbidden bandwidth values and the surface structure.
The acid-base properties of the obtained solid solutions surfaces and binary components of the systems, which are assigned to the weak-acid region (pHiso <7), have been studied. Prognosis concerning the increased activity of such surfaces towards the main gases have been made and proved. The concentration dependences of the studied bulk and surface properties have been established. They possess both smooth and extreme nature. The influence on the dependence type by the degree of difference in the values of the forbidden bandwidth of the initial binary components has been confirmed. The reverse trends in changes with the composition of density (ρr) and pHiso have been substantiated.
The connection between the concentration dependences of bulk and surface properties has been revealed. The possibility of using such connection for a faster, more efficient search for the advanced materials for semiconductor gas analysis and, in particular, for the manufacture of sensors for the main gases trace contamination.
Solid solutions of the InAs-AIIBVI heterosystems. Bulk, surface physical and chemical properties
Authors: Kirovskaya I A , Kopylova E N , Umanskiy I Y , Bukashkina T L , Krasheninin V I 
Published: February 2021

Abstract
Using specifically developed methods, solid solutions of the InAs-AIIBVI (AIIB-ZnS, CdTe) systems have been obtained. In accordance with the results of X-ray studies in combination with the results of micro, submicroscopical studies, they were certified as solid substitution solutions with a cubic sphalerite structure; information on crystal-chemical and structural properties has been obtained; the elemental compositions have been determined, which substantially coincide with the given molar ones. The acid-base properties of the solid solutions surfaces and binary components of the systems revealing a weak-acid character and increased activity towards main gases have been studied. The consistent patterns of changes in bulk and surface properties with a change in composition have been established which obey mainly to a statistical law as applied to the InAs-CdTe system and with extreme manifestations as applied to the InAs-ZnS system, which have been substantiated. The connections between the consistent patterns, the influence of bulk properties (in particular, the forbidden bandwidth, the electronegativity difference) on the surface properties have been revealed. The objectives for the search of the advanced materials for the sensor technology, based on more accessible information on bulk properties, have been set. The practical guidelines have been given on the use of the obtained materials for the manufacture of measuring cells for the main gases trace contamination.
Synthesis and physicochemical inverstigation of hydroxyapatite and wollastonite composite granules
Authors: Shevchenko A E , Solonenko A P , Blesman A I , Polonyankin D A , Chikanova E S 
Published: February 2021

Abstract
Creation of osteoinductive materials based on biocompatible synthetic salts, with a sufficiently high strength and porosity, with the shape which allow filling bone defects with various shapes and sizes is an actual task of modern biomaterial science. In this work, a series of granular materials were obtained from synthetic powders with various proportions of hydroxyapatite and wollastonite using a suspension technology based on the principle of immiscible liquids. Ceramic particles have a spherical shape, microhardness at least 17 HV and open porosity about 50 %. These materials can be used for reparation of bone defects of various locations, shapes and sizes in surgical dentistry, traumatology and orthopaedics.
Experimental research of reagent capsulation process at various methods of carbon dioxide supply
Authors: Shtripling L O , Kholkin E G , Kalinin Yu V , Merkulov V V 
Published: February 2021

Abstract
The article considers some features of the reagent encapsulation method at low temperatures. A setup layout has been created to measure temperature of the encapsulated material while reagent encapsulating. During the experiment, the duration of maintaining the temperature for preparing the next portion was determined. Methods for supplying carbon dioxide to the unit during reagent encapsulation were compared. As a result of the experiment, a more profitable way of supplying carbon dioxide to the unit was determined.
Immobilization of Catalase Using PAES-C Polymer for Wastewater Biological Treatment Research
Authors: Bi Haiyan , Tian Jiaying , Fu Ye , Wang Dazhi , Cai Weijie 
Published: February 2021

Abstract
PAES-C polymer modified by glutaraldehyde (GA) was selected to immobilize the catalase. Infrared spectrum analysis and 1H NMR test the presence of - COOH bond in PAES-C, which favored the cross-linking of PAES-C with catalase. The SEM image showed that its surface had a porous structure, which increased its surface area and provided more active sites for the immobilization of catalase. Indeed, the influence of various factors including GA mass concentration, modification time of GA and carrier, cross-linking time of modified carrier and catalase on the immobilization capacity were deeply investigated. In particular, the achieved optimal conditions for immobilization of catalase were as following: GA mass concentration was set at 1.0wt%, GA modification time was 1.0 h, and the binding time between the modified carrier and the enzyme was 1.0 h. Herein, the findings in this work revealed that PAES-C polymer might be one of the promising candidates for wastewater biological treatment and immobilization of other enzyme.
Analysis on the Characteristics of the Demand for Development and Utilization of Sea Space Resources
Authors: Mamat Gulnigar , Kang Minjie 
Published: February 2021

Abstract
The analysis of the demand characteristics and suitability of elements for the development and utilization of sea space resources is the key content of Marine zoning and planning. Taking Liaoning Province as the research area, this paper analysis the characteristics of the demand for offshore areas through the superposition analysis of the current situation of sea area use and Marine function zoning, and analysis the suitability of the elements of Marine function zoning through the superposition analysis of the Marine function area with the elements of water quality, water depth and coast type. The differences in factor endowment and demand characteristics between regions will provide references for the research on optimal allocation of sea space resources.
Quantitative Evaluation of the Effects of Different Cost Experience Curve on Total Energy Investment Cost: Endogenous VS Exogenous
Authors: Cai Bin , Xia Zimo , Lai Yening , Wen Yan , Song Xiaofang , Xue Feng , Li Zhiyuan 
Published: February 2021

AbstractEndogenous learning curve (endogenous method) and set value exogenously (exogenous method) are two widely used methods for non-fossil energy cost experience curve in energy transition research based on quantitative model. The difference between endogenous method and exogenous method on total energy investment cost are compared, and the effect of key factors such as the learning rate of endogenous curve, cumulative installation capacity of the electricity supply technology, growth pathway of the electricity supply technology are analyzed. Recommendation for pay more attention to the effects of different cost experience curves on results of quantitative models are made for better decision-making support.
A Large Temperature Difference Thermal Substation (LTDTS) with Electric Heat Pump and Thermal Storage Tank
Authors: Sun Jian , Ma Shicai , Huo Cheng , Ge Zhihua , Zhou Shaoxiang 
Published: February 2021

Abstract
A new thermal substation named LTDTS is presented, which could reduce the return water temperature of primary pipeline to below 30 °C. The capacity of an existing heating pipe could be enlarged by more than 50% without changing its flow rate. The LTDTS with single-stage or two-stage heat pump is experimented, which is compared with simulation results. The LTDTS is recommended for large district heating systems due to advantages of reducing the pipe investment and recovering industrial waste heat for lower energy consumption of heating.
Study on the Synthesis of Charge Transfer Complex of Nifedipine and Tetracyanoethylene
Authors: Tian Lu , Wang Fanbo , Wu Jiang , Lv Yuguang 
Published: February 2021

Abstract
Purposes: To construct a new method for the determination of nifedipine and apply it to the determination of in vitro drugs in order to achieve simple and accurate quantitative detection. Procedures: A charge transfer complex of nifedipine tetracyanoethylene was constructed, and the fluorescence intensity changes of the complex and nifedipine were compared. Screen the effect of drug dosage, reaction time and reaction temperature on the fluorescence intensity of the system. Results: Nifedipine is a substance with its own fluorescence characteristics, but its own fluorescence intensity is not as high as expected. Through the addition of tetracyanoethylene, it is found that the fluorescence intensity of nifedipine has been greatly enhanced, combined with ultraviolet A new absorption peak was found in the spectrum, indicating that the two were successfully complexed. Conclusions: The experiment successfully synthesized the nifedipine charge transfer complex, and constructed a new method for the determination of nifedipine content, which is of great significance for the determination of the content of drugs in vitro.
Analysis on Energy Loss Characteristic of a Bidirectional Tubular Turbine Based on Entropy Generation Theory
Authors: Chen Guanheng , Feng Jianjun , Ge Zhenguo , Zhu Guojun , Li Yunzhe , Zhao Yaping 
Published: February 2021

Abstract
To obtain the external characteristic parameters and the distribution of hydraulic loss, ANSYS CFX code is used to for numerical simulations of a tidal bidirectional tubular turbine under positive and reverse conditions. The method of entropy generation analysis is used to obtain the energy loss in the unit and its local entropy generation rate. Besides, the influence of the shaft inclination in the guide vane on the tubular turbine is explored. The results show that there is a certain connection between the traditional hydraulic loss analysis and entropy generation analysis. Entropy generation could be adopted for the measurement of hydraulic loss with its distribution. The total entropy production is dominated by the runner under positive optimal condition, while the ones in the runner and the intake are the highest under reverse optimal condition. In addition, the greater the shaft inclination angle of the guide vane, the larger the total entropy production on the blade surface of the runner under the positive condition.
Power Research on Intelligent Controller of Exposed Tea Fixation Machine Based on STM32
Authors: Han Qinghua , Shi Mingdeng , Li Xiao 
Published: February 2021

Abstract
During the processing of the traditional fixation machine, the temperature is difficult to control, which affects the quality of tea frying. In order to solve this problem, Taking STM32 MCU as the control chip to complete the intelligent control of each functional module. All units are uniformly controlled by a microprocessor, and at the same time, intelligent communication equipment can be used to realize remote monitoring, view real-time production status, and control progress. In addition, the original tea farmer’s machinery can be modified on-site to promote production, and the cost of the installation is lower, which is of great significance to the revival of the tea-horse culture on the “New Silk Road”.
Forecast Method of Energy Public Opinion Based on Conditional Random Field
Authors: Wang Yu , Xie Shengzhen , Tang Junri , Sui Ling , Kou Kaiqi , Wang Zhiqiong 
Published: February 2021

AbstractAs the driving force of development in the new century, the energy problem is an important factor restricting economic development, which is related to a country’s economic security and national security. The public’s views or attitudes towards (heat events related to energy issues, such as the State Grid’s repeated public attention during the 2016 electricity reform) significantly affect the government’s monitoring and guidance of the oil crisis. Ordinary research on emotion prediction regards the change of public attitude towards events as a random process, only considering the influence of the attitude tendency held by users in the early stage on the later stage of emotion development, and not considering the influence of external factors on emotion prediction in the actual situation. This paper proposes a public opinion emotion prediction method based on conditional random fields. Taking the transition probability between external factors as the characteristic transition matrix of the conditional random field, considering the influence of external factors on the development of events, and combining with bidirectional LSTM, the BILSTM-CRF model in this paper is proposed. Experiments show that the emotion prediction method based on conditional random fields can predict the emotion state more accurately, which verifies the superiority of the emotion prediction method based on conditional random fields.
Analysis of a reinforced concrete dome
Authors: Czumaj P , Dudziak S , Kacprzyk Z 
Published: February 2021

Abstract
FEM models of axi-symmetrical reinforced concrete dome with two rings have been analysed. Different complexity level of computational models (2D and 3D), geometry simplifications and FEM codes (Abaqus, FEAS, ARSAP) have been compared. Assessment of building structure deflections has been performed with several approaches, which gave opportunity to confront them and estimate mistakes of most commonly used models.