bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymptotic expansions of solutions in the model of virus dynamics with immune response
Authors: Archibasov A
Published: November 2019

This paper deals with the model of virus dynamics with immune response. Consisting of three integro–differential equations with partial derivatives with two small parameters the singularly perturbed system describes the model. By Vasil’eva – Tikhonov boundary function method, asymptotic expansions of the solutions of the initial boundary value problem are constructed.
Decomposition of enzyme kinetics equations
Authors: Sobolev V
Published: November 2019

The problem of the splitting of singularly perturbed differential systems is invesigated and the application to the problem of suicide substrate kinetics is given.
Reduction of the optimal control problem for a magnetoelectric power drive
Authors: Vidilina O , Voropaeva N
Published: November 2019

A linear-quadratic optimal control problem is considered for a singularly perturbed differential system, which describes the dynamics of a magnetoelectric. The optimal control law is constructed as feedback. Using the method of integral manifolds allows us to reduce the order of the matrix differential Riccati equation.
Optimization algorithms for the conditions of complex catalytic reactions
Authors: Koledina K F , Koledin S N
Published: November 2019

A procedure was developed for the investigation of complex catalytic reactions using optimization algorithms. The first stage is a solution of the inverse problem of chemical kinetics involving the recovery of unknown parameters by single-objective optimization algorithms. In the second stage, based on the kinetic model, we solved the problem of determining the optimal conditions for the reaction resorting to multi-objective optimization algorithms. Parallelization models of computing for solving the multi-objective optimization problem are considered.
Mathematical modeling of radical-chain reaction of isopropylbenzene oxidation
Authors: Vovdenko M K , Ahmerov E A , Koledina K F , Vovdenko A G
Published: November 2019

Isopropylbenzene (IPB) oxidation by air oxygen is an intermediate stage of phenol and acetone production process. Hydroperoxide of isopropylbenzene (HP IPB) is a target product of this process. In this article reaction scheme of isopropylbenzene oxidation was proposed and kinetic model based on reaction scheme developed . Also it was important to choose approach for mathematical simulation of chemical reaction. In this work system of differential equations was used for oxidation reaction simulation. Different types of numerical methods were used for model solution. The results we obtained were compared with data from other researches.
Fatigue life estimation of hydraulically actuated mobile working machines using Internet of Things and Digital Twin concepts
Authors: Zhidchenko V V , Handroos H , Kovartsev A N
Published: November 2019

The method and its implementation are proposed that allow estimating the fatigue life of mechanical structure of hydraulically actuated mobile working machines. The method does not use stress or strain gauges and relies just on the data about the pressure and position of hydraulic cylinders actuating the machine components. These data are measured in real-time during the machine operation and are transmitted via the internet for the processing in the cloud. The simulation model of the machine (Digital Twin) is used for the simulation of machine dynamics on the basis of received data. The Digital twin provides input for the finite-element analysis of machine’s components in order to calculate the stress history of each component. The results of these calculations are used for fatigue life estimation of each component. Applicability of the method is tested by comparing its results with the similar simulation verified by experimental measurements.
Dynamic identification of boundary conditions for convection-diffusion transport model subject to noisy measurements
Authors: Tsyganov A V , Tsyganova Yu V , Kuvshinova A N
Published: November 2019

The paper addresses the problem of dynamic identification of boundary conditions for one-dimensional convection-diffusion transport model based on noisy measurements of the function of interest. Using finite difference method the original model with the partial differential equation is replaced with the discrete linear dynamic system model with noisy multisensor measurements in which boundary conditions are included as the unknown input vector. To solve the problem, the algorithm of simultaneous the state and input vector estimation is used. The results of numerical experiments are presented which confirm the practical applicability of the proposed approach.
A new algorithm used the Chebyshev pseudospectral method to solve the nonlinear second-order Lienard differential equations
Authors: Nhat L A , Lovetskiy K P , Kulyabov D S
Published: November 2019

This article presents a numerical method to determine the approximate solutions of the Lienard equations. It is assumed that the second-order nonlinear Linard differential equations on the range [-1, 1] with the given boundary values. We have to build a new algorithm to find approximate solutions to this problem. This algorithm based on the pseudospectral method using the Chebyshev differentiation matrix (CPM). In this paper, we used the Mathematica version 10.4 to represent the algorithm, numerical results and graphics. In the numerical results, we made a comparison between the CPMs numerical results and the Mathematica’s numerical results. The biggest odds were very small. Therefore, they will be able to be applied to other nonlinear systems such as the Rayleigh equations and Emden-fowler equations.
Molecular Dynamics Modeling of Crack Propagation
Authors: Stepanova L V , Bronnikov S A
Published: November 2019

The study is focused on the application of different approaches for initial crack propagation angle determination. Copper plate with the central crack under complex mechanical stresses (Mode I and Mode II loading) is studied by extensive molecular dynamics simulations using EAM potential. In addition, the complete Williams expansion for the crack tip fields containing higher-order terms is used. Crack propagation angle is obtained by 1) multi-parameter fracture mechanics approach based on three fracture mechanics criteria, MTS, maximum tangential strain and SED; 2) atomistic modeling for mixed-mode loading of plane medium with the central crack. From our simulations we can derive crack propagation directions and crack angles. MD calculations were run for three different values of the mixity parameter: 0.4, 0.5 and 0.6. Calculated values of crack angles were -51:5 deg, -46:6 deg and -42:2 deg accordingly. All the fracture criteria tested give similar values of crack growth angle for different values of the mixity parameter. It is shown that initial crack propagation angles given by both approaches are very close, especially when higher order terms of Williams series expansion for stress/displacement field description are taken into account. Thus, one can conclude that the criteria of classical continuum mechanics MTS and SED can give satisfactory predictions for crack initiation direction. Crack propagation direction angles given by conventional fracture mechanics reasonably agree with the angles obtained from molecular dynamics simulations.
Decentralized multisensor estimation of motion parameters of an object moving along a complex trajectory
Authors: Golubkov A V , Tsyganov A V , Tsyganova Yu V , Petrishchev I O
Published: November 2019

The paper addresses the problem of multisensor estimation of the motion parameters of an object moving along a complex trajectory which consists of parts of the uniform linear and circular motion subject to noisy measurements. To solve the problem, we describe the object motion as a set of linear stochastic models responsible for different parts of the trajectory and use a decentralized multisensor algorithm for estimating the object state vector based on the information form of the Kalman filter. The results of numerical experiments confirm the applicability of the proposed approach.
On some methods for generating extremely multistable systems
Authors: Burkin I M , Kuznetsova O I
Published: November 2019

A multistable dynamic system can demonstrate solutions with fundamentally different behavior depending on the choice of their initial conditions, which poses a threat to its use in practical engineering applications. On the other hand, the system’s multistability may be its undisputed advantage when it is used, for example, to hide information in communication systems and audio encryption schemes to improve the performance of secure communications, since in this case a special choice of initial conditions can play the role of a “secret key”. In this paper, we propose some approaches to the generation of extremely multistable systems containing an infinite number of attractors using mathematical models of systems in Lurie form.
Numerical simulation of high-speed AIIIBV photodetectors within drift-diffusion approximation
Authors: Pisarenko I V , Ryndin E A
Published: November 2019

This paper is focused on a fundamental scientific and technical problem of research and development of high-performance on-chip interconnections for next-generation integrated devices of micro-, nano- and microwave electronics. Previously we proposed an injection laser with functionally integrated optical modulator and double heterostructure, which can be used as an efficient source of light for on-chip optical interconnections. To detect short laser pulses generated by the laser-modulator, a high-speed and technologically compatible photodetector is required. In this paper we develop the non-stationary drift-diffusion model of transient processes in high-speed photodetectors, algorithms of its numerical implementation and applied software intended for one- and two-dimensional simulation of photosensitive optoelectronic devices with various structures. According to the obtained results of drift-diffusion numerical simulation, it is reasonable to research the methods of carrier lifetime reduction in the active regions of photodetectors for on-chip optical interconnections.
Simulation of thermoelectric processes in the semiconductor structure of a solar cell
Authors: Hodakov A M , Smirnov V I , Sergeev V A , Gavrikov A A
Published: November 2019

The paper describes a solar cell thermoelectric model with taking into account the nonlinear temperature dependence of the thermal power density. The temperature distribution in the structure and dependence of the p–n junction overheating on the heating current are reviewed. The results obtained by the modeling and the results obtained with the original apparatus for measuring the thermal resistance of solar cell are compared.
On the results of processing of the telemetry data received from the “AIST” small satellite constellation
Authors: Ivanushkin M A , Tkachenko I S , Safronov S L , Kaurov I V , Volgin S S
Published: November 2019

The article presents the result of the processing of the telemetry data obtained from the “AIST” small satellite constellation. The results of processing telemetry data, obtained during emergency situations on board of the satellites were presented. The influence of the light-dark cycle on the power balance of the satellites was analyzed. The factors affecting the thermal regime of a spacecraft were considered. As a result, the simulation of the thermal conditions of the small satellites was carried out. Then a comparison of the results obtained with the telemetry data was carried out. Thus, the most suitable coating for the processing of honeycomb panels was determined, which reduced systematic overheating, then the imperfection of the procedure for conducting thermal vacuum tests was identified, and finally, recommendations for improving the thermal performance of small satellites “AIST” were formulated.
Mathematical modeling of a multistage electrolysis plant for producing heavy and light water
Authors: Alexandrov R A , Laguntsov N I , Tikhonov S N
Published: November 2019

The work is devoted to the simulation of a multi-stage separation cascade of electrolyzers, designed to produce heavy water as the main product while producing light water as a by-product. The calculation is based on the model of an ideal countercurrent separation cascade without mixing at the entrance to each stage, in which one of the cut coefficients can be chosen arbitrarily in the range of its allowable values, and the value of which is an optimization parameter. It is assumed that taking into account the optimization of the design of the electrolyzer and taking into account energy recovery, the cost of light water will be about $ 0.09/kg, and the cost of heavy water about $ 945/kg.
Influence of radiation defects in a semiconductor structure on the electric field distribution in the air gap of the gas-discharge chamber
Authors: Petrov M A , Phylonin O V , Galanin A A
Published: November 2019

We have proposed and analyzed a theoretical model of the influence of a semiconductor structure both without radiation defects and with their presence on the EMI profile in the air gap of the gas-discharge chamber near the surface of the structure. We have carried out mathematical modeling and comparison of the electric field distribution in the gap for the “ideal” structure (without defects) and structures with a single defect at different depths of its occurrence. A transistor was chosen as the semiconductor structure. We have demonstrated a possibility in principle of using the simulated process for diagnosing radiation defects in electronic equipment under space conditions.
Some features of computer network modelling in the OMNeT++ environment
Authors: Polukarov D Y , Bogdan A P
Published: November 2019

There are many currently available tools for computer network simulation. However, all of these are intended for use by network engineers and are not designed for research tasks. Such simulation models have insufficient flexibility and degree of parameter variability to be used for research purposes. Here, it is proposed to create a simulation model for modern computer networks which allows for the research experimentation. It is proposed to use one of the open packages available which facilitate computer network simulation modelling (for example, OMNeT++) as a base platform. Open-architecture packages allow the researcher to create specialized simulation models. With the help of models created specifically for the needs of research, it will be possible to conduct properly rigorous experiments. This paper utilizes one of the existent implementations of the Barabashi-Albert model for generating computer network topologies. This simulation model can be run and tested within the OMNeT++ discrete event simulator.
Acceleration of calculations using block algorithms for the difference solution of the heat equation
Authors: Golovashkin D L , Yablokova L V , Reznik I D
Published: November 2019

In this paper, we propose taking into account the architectural features of the processor at the stage of constructing the numerical method itself. This idea is illustrated by the example of the synthesis of a new difference scheme for the heat conduction equation, which has traditionally been the object of testing innovations in the theory of difference schemes. The architectural feature hierarchical structure of the computer memory chosen led to considerable communication costs even when a single hardware computational flow was used for organising the calculations. This feature is accounted for in computational linear algebra by using block algorithms, and in the theory of difference schemes, by using the technique of programming ‘tiling’. However, for the two-layer difference schemes of block algorithms for solving grid equations, prior to the proposed work, it was not known because of the impossibility of organising block calculations by using the existing schemes. Here, we propose a new method of constructing two-layer difference schemes and a mixed scheme with a shift as an example of the application of this method. In the course of the experiments, a five-fold acceleration of calculations according to this scheme was demonstrated relative to the traditional explicit model, with the same computational complexity.
Solution of overdetermined systems of equations using the conforming subsystem selection
Authors: Fursov V A , Kotov A P , Goshin Ye V
Published: November 2019

Within this research, we consider an overdetermined system of equations generated on a small number of observations. The degrees of freedom of the overdetermined system and the number of observations are roughly equal. We propose a modification of the Conformed Estimates Method (CEM). The method improvement consists of the usage of an auxiliary system, which is formed from the initial system by reducing the columns. The estimates can be obtained on the higher-level auxiliary subsystem, which is the freest from noise. We consider our method in the problem of computing Rational Polynomial Coefficients (RPCs) from well-established Ground Control Points (GCPs).
Information model and software architecture for the implementation of the digital twin of the turbine rotor
Authors: Bolotov M A , Pechenin V A , Ruzanov N V , Grachev I A
Published: November 2019

The manufacturing errors of the turbine rotor lead to the occurrence of vibrations that limit the acceptable modes of operation of aircraft engines. In order to reduce such vibrations, the current manufacturing technology of the rotor contains a complex procedure for balancing it. Creating a digital twin of the turbine rotor will allow to abandon the balancing procedure and reduce the cost of manufacturing parts. This paper presents such stages of creating a digital twin as the determination of typical errors in the manufacture of a turbine rotor, the construction of a digital twin of a part taking into account the errors in manufacture and the determination of its key characteristics. Analysis of the properties of the twin allows to optimize its parameters and to reduce vibration of the entire engine.
Real-time fatigue features detection
Authors: Gaidar A I , Yakimov P Y
Published: November 2019

Fatigue detection is a very important goal because often tired people lose control of a certain task. So the driver falls asleep during a long trip. Driver’s state is very important because one of the main reasons for motor vehicular accidents is related to driver’s fatigue. To prevent accidents a driver fatigue monitoring and control system that works in real time is required. The main purpose of this study to build a base for developing the drowsiness control system. The article presents drowsiness features study, such as the closed eye, the yawn are required for building the system.
Intelligent OFDM telecommunication system. Part 1. Model of complex and quaternion systems
Authors: Labunets V G , Ostheimer E
Published: November 2019

In this paper, we aim to investigate the superiority and practicability of many-parameter transforms (MPTs) from the physical layer security (PHY-LS) perspective. We propose novel Intelligent OFDM-telecommunication systems based on complex and quaternion MPTs. The new systems use inverse MPT (IMPT) for modulation at the transmitter and MPT for demodulation at the receiver. The purpose of employing the MPT is to improve: 1) the PHY-LS of wireless transmissions against to the wide-band anti-jamming and anti-eavesdropping communication; 2) the bit error rate (BER) performance with respect to the conventional OFDM-TCS; 3) the peak to average power ratio (PAPR). Each MPT depends on finite set of independent parameters (angles). When parameters are changed, many-parametric transform is also changed taking form of a set known (and unknown) orthogonal (or unitary) transforms. For this reason, the concrete values of parameters are specific “key” for entry into OFDM-TCS. Vector of parameters belong to multi-dimension torus space. Scanning of this space for find out the “key” (the concrete values of parameters) is hard problem. MPT has the form of the product of the Jacobi rotation matrixes and it describes a fast algorithm for MPT. The main advantage of using MPT in OFDM TCS is that it is a very flexible anti-eavesdropping and anti-jamming Intelligent OFDM TCS. To the best of our knowledge, this is the first work that utilizes the MPT theory to facilitate the PHY-LS through parameterization of unitary transforms.
Intelligent OFDM telecommunication system. Part 4. Anti-eavesdropping and anti-jamming properties of the system, based on many-parameter and fractional Fourier transforms
Authors: Labunets V G , Martyugin S A , Chasovskikh V P , Smetanin J G , Ostheimer E V
Published: November 2019

In this paper, we aim to investigate the superiority and practicability of many-parameter Fourier transforms (MPFT) from the physical layer security (PHY-LS) perspective. We propose novel Intelligent OFDM-telecommunication system (Intelligent-OFDM-TCS), based on MPFT. New system uses inverse MPFT for modulation at the transmitter and direct MPFT for demodulation at the receiver. The purpose of employing the MPFTs is to improve the PHY-LS of wireless transmissions against to the wide-band anti-jamming communication. Each MPFT depends on finite set of independent parameters (angles), which could be changed independently one from another. When parameters are changed, multi-parametric transform is also changed taking form of a set known (and unknown) orthogonal (or unitary) transforms. We implement the following performances as bit error rate (BER), symbol error rate (SER), the Shannon-Wyner secrecy capacity (SWSC) for novel Intelligent-MPWT-OFDM-TCS. Previous research has shown that the conventional OFDM TCS based on discrete Fourier transform (DFT) has unsatisfactory characteristics in BER, SWSC and in anti-eavesdropping communications. We study Intelligent-MPWT-OFDM-TCS to find out optimal values of angle parameters of MPFT optimized BER, SWSC, anti-eavesdropping effects. Simulation results show that the proposed Intelligent OFDM-TCS have better performances than the conventional OFDM system based on DFT against eavesdropping.
Stochastic parallel algorithm of structural evolution of large Morse clusters
Authors: Kovartsev A N , Popova-Kovartseva D A
Published: November 2019

The formation of large Morse atomic clusters is a complex and time-consuming task, especially when the cluster stiffness equals 14. Currently, optimal cluster conformations are known for sizes up to 240 atoms. The article proposes a parallel stochastic algorithm for the structural evolution of Morse clusters, which makes it possible to find the optimal conformations of large atomic clusters. A significant number of problems associated with the complexity of the task are resolved using the proposed algorithm for optimizing the cluster structure. The results of optimization of Morse clusters for N> 240 are given.
The problem of neural networks communication
Authors: Leontev M Iu , Islenteva V Iu , Mikheev A V , Sviatov K V , Sukhov S V
Published: November 2019

In spite of the successful application of artificial neural networks (ANNs) for the solution of multiple problems (forecasting, language translation, image classification, voice recognition etc.), ANNs are still autonomous entities incapable of communication or exchange of their knowledge. Meanwhile, the ability to communicate is critical for further development of methods of artificial intelligence. We propose and test several methods of communication and knowledge fusion of ANNs. These methods do not require the presence of the initial training data and use only the internal parameters of ANNs. We propose generative iterative and non-iterative methods of ANNs communication. Noniterative methods show the classification accuracy similar to that provided by an ensemble of ANNs. The accuracy of generative methods is similar to a network trained on the joint dataset.
Study of lattice systems separability with the use of parametric identification methods for three-dimensional crystal lattices
Authors: Kirsh D V
Published: November 2019

The paper deals with the problem of lattice systems overlapping, arising in structural identification of crystal lattices in three-dimensional space. The problem leads to a crucial decrease in the accuracy of structural identification and is most evident for four types of lattice systems: orthorhombic, trigonal, tetragonal and cubic. The search for separation boundaries of these systems is based on the use of three parametric identification methods (Bravais unit cell parameters, Wigner-Seitz cell volumes and distances between isosurfaces) and evaluation of several similarity measures for the estimated parameters. Computational experiments were carried out on a large set of simulated reference lattices, by which the type of the distorted lattice was identified. Research results confirmed the existence of the problem of separability for the specified lattice systems, even in the case of ideal lattices (without any distortion). However, the main result was the determination of the parameters distortion range (5% for the edges and 3% for the angles), within which the lattice type is identified correctly.
Blur-robust image registration and stitching
Authors: Donon Y , Paringer R , Kupriyanov A , Goshin Y
Published: November 2019

This paper addresses the functioning of a new key point detection method for images. Such methods are useful in applications as image reconstructions, object signature recognition or video stabilization. The method, Blurred Image Matching (BIM), is based on the comparison of large areas of interest in images. BIM uses a process of blurring and shape comparison that makes the approach unique and in the vast majority of tested cases results in higher performances than other approaches. Among BIM’s key features are the amount of points used for comparison, 19 to 129 times fewer than other methods and of higher quality, allowing faster processing. Another of its key features is a high efficiency in the comparison of images, with a success rate higher than the average of existing methods by 13% to 36%, depending on the images’ characteristics. The method is still in a development stage and will significantly improve, however the results obtained so far are extremely promising, its task solving approach is new and makes a new range of applications necessiting key point detection possible. All this allows us to foresee BIM as a future standard among such methods.
65-year anniversary of Jakov Ye Takhtarov
Authors: Sokolov V O
Published: November 2019

The author briefly tells about the creative activities of the commissioning editor of the journal “Computer Optics”, the leading designer of the Image Processing Systems Institute of Russian Academy of Sciences (IPSI RAS) Jakov Ye. Takhtarov - known specialist in scientific publishing. The article analyses the contribution of jubilee in the formation of the image of scientific and educational institutions of Samara and design of scientific results of the IPSI RAS.
Numerically thermal analysis of a turbine vane at high temperature
Authors: Prapamonthon P , Yooyen S , Sleesongsom S
Published: November 2019

Using conjugate heat transfer, thermal analysis of a turbine vane coated with thermal barrier coating (TBC) at a high temperature is presented. Numerical results are carried out at two turbine inlet temperatures (T
∞) i.e. 783 K (low) and 1566 K (high) under two turbulence intensities (Tus) i.e. 8.3% and 16.6%. The main findings of this research are that for both Tus, the metal surface temperature reduction at the high temperature is higher than that at the low temperature because of the lower heat-flux ratio at the higher temperature. Based on the metal temperature reduction, the increasing inlet temperature has a greater influence than the increasing turbulence intensity. The results also indicate that at T
∞ = 783 K, on the pressure side (PS) the metal surface temperature reduction at Tu = 8.3% is lower than that at Tu = 16.6%, while on the suction side (SS) no significant difference happens when Tu increases. Interestingly, an inverse phenomenon happens for both PS and SS, that is the metal surface temperature reduction at Tu = 8.3% increases above that at Tu = 16.6% when T
∞ increases. This discrepancy may suggest the instability of the surface heat-flux ratio due to complex heat convection at the different inlet temperatures.
Modeling Ice Melting with Selective Absorption of Radiation
Authors: Sleptsov S D , Savvinova N A , Grishin M A
Published: November 2019

Numerical simulation of the melting of an ice layer on a vertical substrate heated by long-wave radiation in a single-phase formulation of the Stefan problem is carried out. A simple model for taking into consider a thin film of water on the irradiated surface is proposed. Ice is presented as selectively absorbing material with two absorption bands. Calculations shows satisfactory agreement with the experiment.
Analysis of power and energy management system for new energy dining car
Authors: Guo Yun , Ouyang Yeyu , Gao Yufei , Wei Bingde
Published: November 2019

Mobile dining car is very popular in Europe and USA because of its advantages of convenient and fast. However, most of dining cars still use traditional power and energy systems, which is not good for the environment. In recent years, the mobile dining car is developing towards light, convenient, and multi-functional. In large and medium-sized cities where business is concentrated, it is worth studying how to make the dining car cleaner and lower carbon, and make it a kind of green and healthy diet culture. In this paper, the green energy is introduced into the dining car power system and cooperated with the flywheel to realize the effective use of photovoltaic cells, achieve zero emission of the dining car, and put an end to the environmental pollution from the source. The social value and the actual effect will be great. Based on the analysis of the actual operating conditions of the dining car, the key parameters such as electrical equipment and motor load of the dining car are obtained, and then the matching calculation of the power system of the new energy dining car is carried out, including the power generation of photovoltaic cells and the storage capacity of flywheel batteries. Then, according to the unique working mode of the dining car, the energy distribution strategy and control system are analysed. Finally, a mathematical model is established and simulated with MATLAB to verify the effectiveness of the design. The results show that the system can complete the day work of the dining car.
Tailoring the Thermal Conductivity of Paraffin and Low-cost Device for Measuring thermal conductivity of Phase Change Material
Authors: Bhandwal Mohit , Verma Amritanshu , Singh Sikarwar Basant
Published: November 2019

In this work, experiment is carried out for melting process of paraffin wax dispersed with high conductive nano-fillers such as Carbon Nanotube (CNT) and ZnO. In addition, a simple, economically viable, easy operating experimental setup is proposed to measure the thermal conductivity of altered PCMs. In this setup, the sample is placed in an insulated transparent cavity and its one end maintained at constant temperature. However, other ends are adiabatic. Temperature at four specific location of melting paraffin in the cavity are measured by T-type thermocouples. The digital camera is used to capture the instantaneous images of the moving thermal front of melting at various time steps. ImageJ® is used to know velocity of the melting front of PCMs from captured images. Based on energy balance, a mathematical expression for estimating the conductivity of the altered PCMs is derived. The measurement of proposed device is compared with commercial thermal conductivity measuring device and data available in the literature. The obtained results have 95% confidence level against the commercial device results and literature results. Post-calibration, experimental study of pure paraffin and altered paraffin wax are carried to know insights of Spatio-temporal energy storing in form of latent heat. This research is useful for design the heat sink for thermal energy management of pulsating heating generating device.
Numerical modeling of interface diffusion during heating of spherical metal heterostructure
Authors: Golovneva E I , Golovnev I F , Igoshkin A M
Published: November 2019

This work is a pilot one and addresses to the development of a physical and mathematical model of alloy formation; this model permits conducting a micro-level detailed study of the influence imposed by the ratio of the thermophysical parameters of the matrix and nanoclusters materials, as well as external controlled parameters on the physical properties of the alloys. The article presents the developed methodological approaches for the numerical simulation of alloys formation with the help of molecular dynamics method (MDM).
Numerical analysis of the water steam jet gasdynamic parameters influence on the hydrocarbon fuel combustion in a pilot burner
Authors: Krasinsky D V , Sharypov O V
Published: November 2019

On the basis of the conserved scalar approach with constrained-equilibrium chemistry model, variant numerical simulation of aerodynamics, heat transfer and the vaporized diesel fuel combustion processes, including soot formation and its effect on radiative heat transfer, has been performed in the pilot burner designed according to a concept of a hydrocarbon fuel combustion enhancement by axial injection of superheated water steam high-speed jet. The aerothermochemical structure of multicomponent reacting flow inside the burner has been analysed for the three cases of numerical study, including two regimes of the water steam axial injection with different jet velocity, and one regime of air injection through the same axial nozzle. The dependencies of the burner flame characteristics and its ecological performance on the given gasdynamic parameters of the discharged steam or air jet have been obtained. Also the numerical study has confirmed the low-NOx features of the burner operational regimes with water steam injection.
PIV measurement of shock wave / laminar boundary layer interaction
Authors: Vishnyakov O I , Polivanov P A , Budovsky A D , Sidorenko A A
Published: November 2019

The paper deals with study the area of interaction incident shock wave with a laminar boundary layer by PIV technique. The several data processing techniques to determine PIV measurements usability in transonic flow with small typical scales are compared in the paper. The results show that the major limitation of the PIV technique are associated with the seeding particles inertia.
Fundamental issues related to flow boiling and condensation in microchannels – experimental challenges and opportunities
Authors: Kuznetsov V V , Shamirzaev A S
Published: November 2019

In recent years, application of the microchannels has received considerable attention due to their capability for thermal management of microelectronic equipment, high power devices and development of compact evaporators. The present paper focuses at a discussion of the heat transfer during flow boiling and condensation in microchannels of the heat sink to identify the methods to improve heat transfer performance and select the physically based models for heat transfer prediction. The main purpose of this study is to discuss the mechanisms of heat transfer in microchannels at different aspect ratio for the three-sided heating case using the experimental data were obtained for refrigerant R134a and dielectric fluid.
Direct numerical simulation of turbulent flow and heat transfer in a hexagonal rod bundle
Authors: Sergeenko K M , Yu Chulyunin A , Krasnopolsky B I
Published: November 2019

The aspects of numerical simulation of heat transfer in a flow along the hexagonal rod bundle are discussed in the present work. The direct numerical simulation is used to investigate the flow with Reynolds and Prandtl numbers varying in the range from 2500 to 10000 and 0.0043 to 7 correspondingly. The obtained simulation results demonstrate good agreement with available experimental data and semi-empirical correlations for the thermo-hydraulic characteristics of the channel. The empirical correlations for the Nusselt number distributions summarizing the results of the numerical simulations are proposed. The preliminary calculations have shown that the modelled time averaging interval is comparable with the initial transition time interval. This observation allows applying the approach, proposed in [7], to speed up the simulations.
Study of total heat losses in experiments with shear-driving liquid films in a mini-channel with intense heating
Authors: Zaitsev D V , Tkachenko E M
Published: November 2019

Recent works by the authors have shown the high efficiency of using thin liquid films, moving under the action of gas in a flat mini-channel, for removing high heat fluxes. In the present work, we carefully study the total heat losses in such a system. Total heat losses are divided into two portions: heat losses from the heating coil to the atmosphere and heat spreadings from the heater to the substrate. The relative values of the total heat losses prior to the crisis are decreasing with increasing critical heat flux and do not exceed approximately 20% for the critical heat flux between 500 and 900 W/cm2.
Hydraulic resistance and heat transfer augmentation in pipes with inner helical micro-ribs: Review, data generalisation, and technical recommendations
Authors: Popov I. A. , Skrypnik A. N. , Schelchkov A. V.
Published: November 2019

The paper presents the data generalization and development of general correlations for heat transfer and pressure drop in pipes with inner helical micro-ribs. Heat transfer and friction coefficient data were gathered from related investigations on single-phase turbulent flow of Newtonian fluid in pipes with various shape inner helically-ribbed surfaces
Semi-automatic detection of hepatic tumor in computed tomography images
Authors: Sáenz F , Vera M , López J , Huérfano Y , Valbuena O , Vera M I , Gelvez-Almeida E , Salazar-Torres J
Published: November 2019

In this work, the main purpose is develop a computational segmentation strategy for liver tumor semiautomatic detection. This strategy considers three-dimensional computed tomography images and it consists of techniques application that, on the one hand, diminish the noise and detect the edges of the objects present in those images and, on the other hand, generate the liver tumor morphology. For this, the sequence of techniques composed of gaussian smoothing, gradient magnitude, median filter, region growing and binary morphological dilation are used. The value obtained, for the metric called Dice score, show a good correlation between manual segmentation, performed by a hepatologist, and the tumor segmentation obtained using the proposed technique. This type of segmentation is the extreme utility for the characterization of hepatic tumors and the planning of the clinical behavior to be followed in the treatment of this human liver disease.
A two patch model for the population dynamics of mosquito-borne diseases
Authors: Gómez-Hernández E A , Ibargüen-Mondragón E
Published: November 2019

In this work, a model on the interaction dynamics of mosquitoes causing vector-borne diseases is formulated, without consider the human population as dynamic variables and including mobility from eulerian approach, in which the populations are not assigned to a place in particular, but they move between patches at certain rates. The results suggest that in order to eradicate the disease, the mosquito population in each patch must be controlled, but in order to reduce the magnitude of an epidemic outbreak, the transformation rate from susceptible to infected, the migration and immigration rate must be controlled.
Estimation of informal transport motorcycle emissions in the city of Ocaña, Colombia, as research training strategy for environmental engineering students
Authors: Fonseca Herreño L C , Valdes Solano D M , Alba Maldonado J M
Published: November 2019

Mototaxism in Colombia is considered an informal employment, in which a motorcycle is used to provide public service; it is a door-to-door service, without established routes, at a perennial frequency and low fares. This modality of employment began in the city of Ocaña about a decade ago, now it has popularized due to population growth, regional migration crisis and high unemployment rates. The “Universidad Francisco de Paula Santander” and the “Universidad Manuela Beltran” in Ocaña, Colombia; from their missional framework, aim to incentivize research training, raising the need to build training projects for students of second and third semester of environmental engineering, integrating statistics as a tool for decision making and data analyses, bringing the academy closer to contextual problems that the students can understand as their own. Environmental engineering students were able to participate with presentation of their results in different events, incentivizing their interest towards research and the use of statistics and mathematics as an important tool for data management and interpretation.
Parameter estimation, sensitivity and control strategies analysis in the spread of influenza in Mexico
Authors: Prieto K , Ibarguen-Mondragon E
Published: November 2019

In this paper we address a parameter estimation, sensitivity and control strategies analyses for influenza disease using a model the flows of people between four states: susceptible, exposed, infectious, recovered. We solved a curve-fitting mathematical model to Mexican influenza data using a nonlinear least-square method and the Landweber iteration. An optimal control problem is formulated and analyzed based on models between four states: susceptible, exposed, infectious, recovered; model considering educational campaign, vaccination and medical treatment as strategies for disease control. The sensitivity analysis is performed to determine which model parameters are the most important to disease transmission and prevalence. The numeric results suggest that an adequate implementation of these strategies during the outbreak of an epidemic could significantly mitigate the propagation of the disease.
Strengthening mathematical interpretation competence through the portfolio as a learning tool
Authors: Niño Villan M L , Gallardo Pérez H J , Villamizar Jaimes D
Published: November 2019

The purpose of the research is to strengthen the competence of mathematical interpretation through the portfolio as a learning tool in an educational institution of the “Municipio de Gramalote, Norte de Santander, Colombia”. The research is carried out from the socio-critical approach, qualitative paradigm and the chosen method is action research. The information gathering process was developed using the techniques of: participant observation and focus group. The key informants were two high school mathematics teachers and eighth grade students. The results show that in the diagnosis the participants’ lack of knowledge regarding the process of mathematical interpretation was evidenced; elements of knowledge are identified from the previous knowledge of the students and the preparation of the researcher teacher in the didactic sequence. The use of a tool such as the portfolio made it possible to motivate the learning process and to evidence in an orderly manner the abilities and capacities empowered by the students; there was an appropriation of learning around the analysis and interpretation of mathematics from concrete situations in the daily lives of the students, taking up their previous knowledge and using didactic elements and resources from their environment.
Human computer interaction in transport, a systematic literature review
Authors: Martinez-Toro G M , Ariza-Zabala G C , Rico Bautista D W , Romero-Riaño E
Published: November 2019

To enhance the performance of transportation systems a wide range of computer applications and computer software have been developed, which help users into the decision-making process. This paper intends to go into the field of human-computer interaction and transportation, by carrying out a literature review in order to recognize the usefulness of human-computer interaction and the way that it is used in the topic of transportation. human-computer interaction perspectives are applicable to describe, to analyze, to improve issues as user experience, user security, urban development, business model and so for. Understanding the way, a system is utilized is crucial to achieve the purpose of its design.
It governance model for state entities, as support for compliance with the information security and privacy component in the framework of the digital government policy
Authors: Ávila C , Chinchilla E J , Velásquez Pérez T
Published: November 2019

This article proposes an information technology governance model that facilitates the direction, control and fulfillment of the objectives of the implementation and maintenance of the information security and privacy program proposed by the Ministry of Information Technology and Government Communications Colombian to state organizations in the framework of the digital government policy. Based on the identification of the regulations of the Colombia state for the implementation of the information security and privacy model, the analysis of the existing information technology governance frameworks that converge on the governance and management objectives of the information security and privacy model is continued and finally the model is structured of governance. contributes to the technological development of the Colombia society through the construction of an innovative tool that facilitates the direction, control and rapid adoption of the management system of information security and privacy defined by the Colombia State, which results in the assurance and privacy of information of all Colombian that is in the hands of state entities, reducing frauds, the exposure of our personal information among other risks.
Fuel-air ratio required for combustion and analysis of gases in an intermittent kiln
Authors: Guerrero Gómez G
Published: November 2019

The air-fuel ratio necessary for coal combustion and the study of atmospheric emissions generated in an intermittent kiln of brickworks la Pradera were determined. A mass balance of the coal constituents and an isokinetic sampling of the gas emissions generated in the kiln were carried out. This was done according to the methodology and procedures established by “Ministerio de Ambiente, Vivienda y Desarrollo Territorial” in the protocol for the control and monitoring of atmospheric pollution generated by stationary sources. A combustion gas analyzer was used to measure the concentration of pollutants such as particulate matter, sulfur dioxide, nitrogen oxides, hydrochloric and hydrofluoric acids, and carbon dioxide and monoxide. The average concentrations of particle material, nitrogen oxides, sulfur dioxide, hydrochloric and hydrofluoric acids through the kiln chimney were 1228.60 mg/Nm3, 625.50 mg/Nm3, 563.10 mg/Nm3, 21.50 mg/Nm3 and 6.40 mg/Nm3 respectively, under reference conditions and adjusted to 18% oxygen. The kiln used has energy losses due to incomplete combustion of coal and sensible heat in the flue gases. The concentrations of nitrogen oxides, sulfur dioxides, and particulate matter are above the standard value and do not meet the permissible emission standard. On the other hand, halides do meet the respective standard.