Theoretical studies of the temperature distribution during laser heating of the TiO2 precursor film on the FTO/glass substrate have been carried out. The simulation was performed on the basis of a numerical solution of the heat equation in the Matlab program to determine the energy density of the laser radiation necessary for crystallization of TiO2. It was shown that on the surface of the TiO2 precursor the temperature reaches a maximum value at a time point of 133 ns with the Gaussian temporal form of the laser pulse. The optimum energy density for crystallization of the TiO2 precursor film with the nanosecond pulse duration is 1.3-1.6 J/cm2, when the film thickness temperature corresponds to 400-500 °C. The obtained results of the simulation are consistent with experimental studies.
Keywords: numerical simulation, laser heating, temperature distribution, TiO2 film, solar cell
The paper contains the results of investigation of effectiveness of application of various models oriented towards interval time series (ITS) to forecasting behavior of gas distribution networks (GDS) parameters involving the real data obtained during the process of their continuous control. The necessity of taking into account the factor of seasonality caused by periodic fluctuations in the level of the corresponding variable is justified. A comparative analysis of the properties of the special interval modification of the model based on exponential smoothing, neural network and hybrid prediction models in relation to the ITS with seasonality is performed, their merits and demerits are noted.
Keywords: interval-valued time series, exponential smoothing model, neural model, long short-term memory, hybrid model
The article suggests a technique for automatic segmentation of satellite images on the basis of convolutional neural networks into several classes, such as buildings, rivers, roads, etc. The software implementation of the proposed methodology took the second place in the competition for the segmentation of satellite imagery on the Kaggle platoform in competition: Dstl Satellite Imagery Feature Detection. The article describes how to prepare images for the training of neural network and reveal details for full dataflow and the principles of the traning. The structure of the neural network for segmentation is proposed. The network is built on the basis of UNET with additional BatchNormalization and Dropout layers, based on double convolution blocks. A procedure for cross-evaluation is described to assess the accuracy of the models obtained. The descriptions of algorithms for postprocessing and the technique of segmentation refinement are presented by using an ensemble of several models. A specialized model is proposed for finding objects of small size, such as "cars" and "motorcycles". An overview of other methods used to solve this problem is also given, which were not included in the final solution. In the experimental results it is shown that the efficiency of neural networks in this task is extremely high and it is possible to automatically prepare a layout of the terrain similar to the markup made by human. And thereby it allows to save money, since significant financial resources are being spent on manual marking.
Keywords: convolutional neural nets, sattelite imagery, image segmentation, machine learning, crossvalidation, Jaccard coefficient, UNET network, image classification, computer vision, contest results
Examples of bearings with hydrodynamic wedge are mapped to specific features of the incompressible lubrication (drip liquid) and compressible (gas). Due to the physical nature of the processes occurring in the gas lubricating layer. The main advantages of axial and radial gas dynamic bearing with spiral mikrokanale, which was the most widely and effective used not only as bearings, but also as the best contactless seal.
Keywords: lubrication layer, hydrodynamic wedge, pressure, load capacity, helical grooves, optimal parameters
The article deals with the movement of erythrocytes along the narrow capillaries with a diameter smaller than the erythrocyte diameter. Red blood cell in narrow capillary has tank-treading motion. The erythrocyte rotation frequency reaches several dozen revolutions per second. Electric charges located on the surface of the erythrocyte, move together with the erythrocyte membrane and create a magnetic field in the surrounding space. A two-dimensional model of erythrocyte movement along narrow capillaries was constructed. If the erythrocyte surface area and erythrocyte charge are known, then the density of charges on the erythrocyte membrane can be determined. The magnetic field strength of a moving charged particle can be determined if the particle charge, the particle velocity, the distance from the particle to the point at which the magnetic field strength is determined, the angle between the direction of the particle velocity and the direct connecting particle, and the point at which the tension is determined are known. The total strength of the magnetic field of several moving charged particles is defined as the vector sum of the magnetic field strengths of the individual moving charged particles. In the two-dimensional model it is assumed that the red blood cells are rectangles that move along the capillary, and the erythrocyte membrane is the sides of the rectangle. Discrete charges are located on the sides of the rectangle and move either clockwise or counterclockwise. It is possible two variants. Their membranes either rotate in the same direction or in opposite directions. Calculations were carried out for both variants and at different rates of rotation of erythrocyte membranes (from 0 to 50 revolutions per second) and distances between red blood cells. It is shown that at distances between erythrocytes smaller than the two capillary diameters, the influence of neighboring red blood cells can be neglected (the difference is less than 3%).
Keywords: "mathematical model, magnetic field, erythrocytes, narrow capillaries, magnetic field strength "
In this article, we briefly reviewed the problem of image quality loss. Methods for restoring defocused images are considered and analyzed. Describes lubrication functions and ways of defocusing the image, as well as a mechanism for eliminating the three main types of image blurring. A number of experiments were conducted on the defocused images. An algorithm for deconvolving an image using a Wiener filter and using the Tikhonov regularization method is disassembled. The analysis of the efficiency of the Wiener filter and Tikhonov regularization for blurred images is performed. The comparative analysis was carried out using the developed software for the restoration of defocused images in the Microsoft Visual Studio 2012 environment. For the Fourier transform, the library was used - aForge. A certain dependence of the execution time of the algorithm on the size of the image to be reconstructed. It is established that on the tested problems - the time complexity of the Wiener filter is 1.1 times less than the time complexity of Tikhonov regularization.
Keywords: Wiener filter, Wiener deconvolution, Tikhonov regularization, image reconstruction, blurred images, motion blur, Gaussian blur
in the article the questions of modeling of thermal effects in vortex tubes with application software, for example, CFD-complex is Studied. Discusses the practical applications of thermal effect in vortex tubes, is proposed using the process of refrigeration in vortex tubes for climate control in vegetable stores with the aim of improving the safety of the products. This article is of interest to a wide circle of readers, dealing with issues of simulation software packages.
Keywords: heat effect, cooling, heating, microclimate, modeling, CAD software program, 3D model. CFD-complex is Studied, FlowVision
Using a device of close homogeneous exponential queueing networks (QN) a mathematical model of an distributed information system functiouning for solving the problem of getting integral indexis on the basis of local computing network on the basis of three- level client server arhitecture. The base correlation for transitione matrix probabilities constraction and intensitiese of service at the network nodes are given.The peculiarity of the model being worked out is in making a selective choice of information at the database servers and via the channel of communication not the full data base is transmitted but some separate parts of it, which satisfy the conditions of SQL-request search.
Keywords: Distributed information system, distributed data base, local computing system, mass service network, conceptual model, exponential law of distributing the random value, stationary probability, mark process, the global balance equation, system reaction tim
On the basis of Reynolds's equations for thin layers of viscous Newtonian liquid laws of distribution of pressure are found in the incompressible and compressed bearing layers of a step support. For achievement of physically clearer comparison of lubricant properties and the bearing ability of two different lubricant environments the flat model of a step support is used. The algorithms of calculation of carrying power and rigidity of both lubricant layers allowing to pass to statement and the solution of problems of optimization of dimensionless geometrical parameters and comparative integrated characteristics of hydrodynamic and gasdynamic step support of sliding are received.
Keywords: lubricant layer, viscosity, pressure, density, Reynolds's equations, splines, Petrov's number
A model for choosing the optimal version of the excavator arm is presented, combining classical methods of decision making and statistical modeling of the bearing capacity and loading parameters
Keywords: decision making, reliability, resource, modeling, single-bucket excavator, hilt, optimization
The analysis of 11 image processing algorithms for microobjects recognition in the histological sections of the biotissue is carried out. It is shown that for images obtained with different microscopes and dyes, there is no one universal method of image processing. The choice of the algorithm depends to a large extent on the specific type of microscope. Considered algorithms give more reliable results for high-contrast images when using a confocal microscope.
Keywords: image processing, edge detection, biological microobjects, OpenCV, ImageJ, morphometric processing, matching
Energy costs for grain drying are about 30% of the total energy consumption for grain produc-tion. Reducing the energy consumption of drying is possible due to the use of a microwave field. In this case, it is necessary to develop a design of a convection drying zone with a microwave field which will provide uniform drying of the grain throughout the volume. For this purpose, it is advis-able to carry out the simulation of the process. The developed computer model of heat and moisture exchange in the grain layer allows to model one under varying parameters of the grain layer and the drying agent. A computer model implements a stepwise calculation method. According to this method, the grain layer is represented as a series of computer models of the elementary layer. The grain layer is divided into three sections. The specific power of the microwave field is set to con-stant throughout each part. In addition, the model takes into account the features of changing in the specific power of the microwave field in the drying zone from the moisture content of the grain and the distance from the magnetron. The air flow in the microwave convection zone can has an im-portant value for the energy intensity of the process. The paper presents the results of modeling grain drying with two variants of air distribution in the microwave convection zone. Graphs of changes in grain moisture in each of the sections of the layer are given. It is shown that when the air moves from the magnetron, the time and the non-uniformity of drying decrease.
Keywords: drying of grain, grain layer, microwave field, microwave - convection drying, heat and - moisture exchange, computer model, modeling
Background: The quality of electricity is one of the main problems necessary for the normal functioning of responsible technological processes in which a slight distortion of the supply voltage can lead to a violation of the normal operation of enterprises. There are several solutions to this problem: uninterruptible power systems, fast automatic power reserve technology (FAPR), dynamic voltage distortion compensator (DVDC). The most interesting solution is the application of dynamic voltage distortion. Material and methods: The principles of constructing a dynamic voltage distortion compensator with multilevel voltage inverters are investigated. An imitation model constructed under the following assumptions is proposed: an ideal case of the main circuit system (without higher harmonics) is considered, the nonlinearity of the transformer is not taken into account, short-circuit currents are absent, only constant load power is used. Assumptions are justified by the fact that in practice their error is no more than 3-5%, which is permissible. The results are obtained by modeling the system in the MatLab 2016b package. Results: A fundamentally new structural and functional scheme of a dynamic voltage distortion compensator with a multilevel system is developed. The requirements for the dynamic compensator of voltage distortion, load, LC-filters, current-voltage transformers and a converter are determined. Simulation of the simulation model has shown that the system works and corresponds to the expected results. Conclusions: The proposed voltage compensation system will solve the problem of the normal functioning of technological processes. The simulation results showed that the declared functional of the DVDC provides compensation of the voltage level in a given range of voltage dips. The obtained results can be used to stabilize the power supply: in the power supply systems of medical institutions, electric transport, critical energy facilities of a high category.
Keywords: Dynamic voltage distortion compensator (DVDC), automatic control system, operation modes of DVDC, model of the DVDC system, multilevel voltage inverter, simulation model, voltage distortion, volt-additional transformer, electric power, voltage failure
Since users can have very different preferences, the personalization of surrounding devices is of paramount importance. Several approaches have been proposed for establishing such personalization in the form of machine learning or more specialized approaches to learning based on scientific knowledge and innovations. Despite great advances in optimization, evolutionary algorithms in this context have been little studied, mainly because they are known as elements that are slow to learn. Anyway, at present there are quite fast optimizers based on evolutionary algorithms. In this article, an analysis is made of the suitability of evolutionary algorithms for "ambient intelligence".
Keywords: ambient intelligence, evolutionary algorithms, personalization, optimizer, CMA-ES, user, controller, machine Learning, sensor
A research software complex was developed to form the behavior of a mobile robot in a nonstationary environment based on the e-puck robot. The complex includes the method of additional training of the robot, cluster analysis and the modified algorithm Q-learning, which ensures the robot's movement to the target. The recognition algorithm is based on the concept of ""similarity"" between images from the robot's camera and the standard marks of object clusters formed in the learning process. Standards are formed gradually from ""similar"" labels. If the label is ""similar"" to the existing standard, then the object has already met before and the corresponding action of the robot is also defined. Otherwise, a new cluster is created, so there is additional training. The number of objects is almost unlimited. To ensure the movement of the robot to the target, the Q-learning algorithm is used with reinforcement. It is based on the use of the matrix of the expected reward Q. Knowing the current state of the environment, the robot chooses an action that is expected to bring the maximum reward. The reward is given if the target label is in a certain area of the frame of the video camera and has a certain size. Initially, the matrix Q is given randomly. In addition, at each step the matrix values change in such a way that the matrix gives optimal control in any situation. In the case of the robot e-puck, the possible actions are rectilinear motion or turn (left / right). To overcome the problem with several targets, the algorithm uses several reward matrices Q. When a new goal occurs, the algorithm creates a new reward matrix. In this modification, all matrices Q are subjected, regardless of the target the robot is looking for. The final decision on the action of the robot takes on the basis of a matrix corresponding to the current goal. Despite the difficulties and problems that have arisen, it has been possible to implement a complex that can be relatively easily transferred to another physical platform and can be used to create more sophisticated intelligent systems.
Keywords: autonomous mobile robot e-puck, Q-Learning algorithm, cluster analysis, training, recognition, digital methods of processing video images
The article describes the problems of mathematical modeling of large systems. Scientific novelty of the work consists in the implementation of a new numerical method for solving systems of linear algebraic equations. This method is based on a targeted random search and stochastic calculations whith using of cloud technologies.
Keywords: system of linear algebraic equations, cloud computing, self-organization, metric
Article desribes the change in the ST-segment offset of the electrocardiagramm according to the variaty effects like fluctuations, respiration, additive noises, and heart rate deviation. Authors proposes to identify the ST-segment location in already synthesised ECG signal, adding an offset with consecutive nonlinear interpolation using National Instruments LabVIEW BioMedical Toolkit
Keywords: Electrocardiogram, ST-segment, synthesized ECG, elevation, depression, heart rate, T-tooth, isoline, smoothing, interpolation
The article discusses the aspects of coordination of the file formats used for recording biological signals. The primary attention is paid to the data structure and the conversions of its own format to standard formats and vice versa when conducting state tests and certification of a medical device.
Keywords: ECG, EKS, EDF, MIT-BIH, data format, data format conversion, electrocardiogram
In this paper, a choice is made of the data processing algorithm necessary for the development of analytical software in the complex project ""Development and creation of high-tech production of an innovative system for the integrated accounting, recording and analysis of energy consumption and water consumption by industrial enterprises and utilities"" The review of existing algorithms and prediction methods in systems with a large number of parameters and a large epoch of analysis is made. A specific application for the desired algorithm is predicting the consumption of energy resources and water. Based on the review of algorithms, the algorithms chosen are most suitable for this task. The tandem use of the decision tree construction and the genetic prediction algorithm is considered. Further tasks that need to be solved for effective implementation of these algorithms in the development of analytical software are formulated.
Keywords: analytical software, forecasting, genetic algorithm
The article investigates approaches to managing currency risks on the Moscow exchange based on static hedging and taking into account the features of the Russian derivatives market. For more delicate managing currency risks, it is proposed to use barrier options that are not traded on the Moscow exchange. It is shown that the barrier option can be replicated with the portfolio of European options, the strike prices of which are the barrier and the strike price of the barrier option. The main idea behind the approach applied is replication of zero price of the up-an-out call (in the case of crossing the barrier) by the linear combination of European call options with different time to expiry. Examples of constructing replicating portfolios of options on the futures contract for the US dollar - Russian ruble are given . Further analysis of the portfolio's value dynamics demonstrates the inadequacy of the classical Black-Scholes model for the Russian derivatives market. The approaches of static hedging barrier options in jump models are disscussed.
Keywords: mathematical modeling, numerical method, mathematical finance, barrier options, Black-Scholes model, static hedging, Levy models, derivatives market.
The questions of decision-making are considered at the development of a complex tourist product, which includes places of leisure and recreation, relocations, places of residence and others. The multicriteria problem of choosing the optimal variant of the tour with the given criteria and user ratings has been set and solved. The proposed model can be used to build a decision support system for the development of tours around Russia.
Keywords: decision theory, expert assessments, the theory of formal languages and grammars, optimization, intellectual systems
The growing interest in travel around Russia and the lack of information support determine the relevance of developing decision support systems in the tourism industry. The work presents the results of information modeling of such a system that allows, based on monitoring of thematic Internet resources, to create a database of tourist sites and events, places of residence, transport routes and based on user estimates, form a completed tourist product that appropriate the requirements. The obtained models are the basis for the development of the software environment.
Keywords: information modeling, universal modeling language UML, decision support system
An important component of electronic document management and training systems is considered - a full-text search engine that allows to implement convenient means of searching for information of interest on the contents of electronic documents. Estimates of the efficiency of full-text search in databases are given.
Keywords: Database, full-text search, database management system, MySQL, PostgreSQL, Oracle
The article deals with the construction of exponential smoothing model and an additive model of the time series according to the quarterly data of the customs payments volumes for the import of a group of goods 72 «Ferrous metals» and 73 «Goods from ferrous metals» for the period from 2014 up to the first quarter of 2017 in the region of Rostov Customs operation. According to the received models, the forecast for the second quarter of 2017 has been made.
Keywords: econometrics, time series, adaptive methods, exponential average, modeling, forecasting, customs payments
In this work, we carried out a study of algorithms implemented by the system of human identification based on various criteria. Three main approaches to face recognition are considered. The advantages and disadvantages of approaches revealed during implementation are given.
Keywords: Databases, face recognition, pattern recognition, hidden Markov models, principal component analysis, neural networks