=Paper=
{{Paper
|id=Vol-2763/CPT2020_paper_s7-8
|storemode=property
|title=Intelligent system of forest area recognition for tasks of geographically distributed economic systems
|pdfUrl=https://ceur-ws.org/Vol-2763/CPT2020_paper_s7-8.pdf
|volume=Vol-2763
|authors=А.А. Kuzmenko,D.А. Kondrashov,А.S. Sazonova,L.B. Filippova,R.А. Filippov
}}
==Intelligent system of forest area recognition for tasks of geographically distributed economic systems==
Intelligent system of forest area recognition for tasks of geographically distributed economic systems А.А. Kuzmenko, D.А. Kondrashov, А.S. Sazonova, L.B. Filippova, R.А. Filippov alex-rf-32@yandex.ru | kuzmenko-alexandr@yandex.ru | asazonova@list.ru | libv88@mail.ru | redfil@mail.ru Bryansk State Technical University, Bryansk, Russia For a long period, our country has been in the process of radical transformations of the state economic system, associated with the final transition to a market system of management, the development of local self-government and the independence of economic entities. In the new conditions of the emerging market, the issues of ensuring the sustainable development of territorial economic systems and sectors of the economy, which are the source and guarantor of social stability, employment, a high level and quality of life of the population of the regions, come to the fore. The paper deals with an intelligent system for recognizing the dynamics of changes in forest areas based on automatic pattern recognition methods. The existing methods of processing graphical information, classification and clustering methods that are of value within the framework of the problems being solved are considered, and several original algorithms are proposed. LTP and FFT algorithms were selected as feature extractors of which the simplest and most productive option is LTP. Histogram equalization algorithms, median and Gaussian filters to eliminate noise and remove small image details are chosen to pre- process the image. Euclidean and Mahalanobis distances were used as separability measures. Naive Bayes classifier is proposed to use for classification. Key words: intelligent systems, pattern recognition, geographically distributed, economic systems The scale and size of the window can only be set 1. Introduction experimentally, which will be done in the corresponding Modern software market is able to offer a system for part of the work. Reducing the amount of information automation or solving almost any task. Problems of forest means applying filters to the image that suppress noise and protection and forest management were also not ignored: unnecessary details. Color equalization involves there is a wide range of software that automates accounting equalizing the intensities in the channels used – the so- activities, is integrated with GIS systems and provides called equalization of the image histogram. forest planning capabilities, access to tax and cadastral 3. Image Filtering maps, as well as acquisition and processing capabilities of remote sensing data. Most of the image transformation methods used in this There are not many systems focused on automatic paper are based on convolution. Correlation and processing of satellite images, and their functionality is convolution are two closely related concepts. Correlation unique compared to their analogues. For example, is the process of moving the filter mask over an image and "ScanEx Image Processor" system is quite versatile and calculating the sum of the products of the mask element allows processing both the supplied database of images values and the pixel values that the corresponding mask and images from its own sources, but the system is closed, elements fall on. Сonvolution mechanisms are the same, provides a trial version only by agreement with the except the filter mask is pre-rotated 180° [3,9]. manufacturer, and does not allow modification of the Analytically, convolution is expressed as follows. algorithms used. "Forestry and land use" is focused only The filter, or convolution kernel, is a square or on processing the vendor's own database of images. rectangular matrix with an odd number of rows and "KEDR" system is available only to state structures of columns. The odd number is due to the fact that the Amur and Primorye territories and does not even have convolution result is assigned to the pixel, the response open documents. Such introductory conditions complicate center of the kernel (Fig. 1). the search for the turnkey system. 2. Materials and methods When image recognition is based on bitmap graphics, arrays of image pixels play the role of data arrays. Raw data sets have extra information, which in addition to increasing computational complexity can lead to the so- called retraining of classifiers. Also, feature extraction and classification algorithms are sensitive to the transformation of the data used to different extend. So, to create a stable algorithm for recognizing the forest texture, it is necessary to set: − image zoom in m/pixel (m/px); − optimal image segment size suitable for classification; − algorithm for reducing the amount of information in Fig. 1. Application of Sobel filter (edge detection) the image; Convolution cannot be used for extreme pixels. This − algorithm for equalizing the color of photos. problem is solved by creating an intermediate image with Copyright © 2020 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0) the completed extreme rows and columns. Pixels can be − 𝑥𝑥𝑥𝑥 is 𝑛𝑛-value of value vector; either zero-intensive or copy the extreme ones. The second − 𝑖𝑖 is unit imaginary number; method is used in this work. − 𝑘𝑘 is a complex sinusoid frequency. Filtering methods are distinguished in the spatial and The original data for the algorithm is a vector of frequency domains. Processing methods in the spatial function values with a specified step. The result of the domain contain approaches based on direct manipulation algorithm is a vector of complex numbers, for which the of image pixels. Spatial processing is characterized by the index is the frequency value, and the real and imaginary equation [4]: parts are the coordinates of the radius vector point. 𝑔𝑔(𝑥𝑥, 𝑦𝑦) = 𝑇𝑇[𝑓𝑓(𝑥𝑥, 𝑦𝑦)], (1) The frequency and amplitude components of the signal where: 𝑓𝑓(𝑥𝑥, 𝑦𝑦) is an input image; 𝑔𝑔(𝑥𝑥, 𝑦𝑦) is an output are vector arguments and the complex number module image; T is an operator on 𝑓𝑓 in a certain point (𝑥𝑥, 𝑦𝑦). respectively. The module is defined as the length of the The main approach to defining a neighborhood is to radius vector: select a rectangular area around the original pixel ( ,𝑦𝑦). To , (4) find 𝑔𝑔 value at a certain point (𝑥𝑥,), 𝑓𝑓- function value is used where 𝑎𝑎 is the real part, 𝑎𝑎 is the argument of the imaginary inside a certain neighborhood of the point. This approach part. is based on the use of masks – two-dimensional arrays of The argument is defined as the angle between the function values. The most well-known methods in this radius vector and the plane: category are linear and median filtering. An averaging filter is used as a linear filter; its output (5) value is the average value in its mask neighborhood. The The image cannot be represented as a one-dimensional same filter is used for removing image graininess caused vector of numbers without losing important information. by impulse noise. To obtain the spectrum of a two-dimensional vector of Fig. 2 shows an example of processing a noisy image numbers, FFT is first applied to the columns, and then to with median and linear filters [4,10]. the rows of the matrix formed (Fig. 3). Based on experiments [4], it is concluded that a median filter is more suitable for impulse noise, which preserves good element boundaries and has a high speed. Filtering in the frequency domain is based on Fourier transformation. Transformation means that any function that periodically reproduces its values can be represented as the sum of sine/cosine of different frequencies multiplied by some coefficients. This sum is called Fourier series. One of the most important properties of Fourier transformation is that its result can be restored to its original form without loss of information. Fig. 2. Sample of median and linear filtering Fig. 3. Feature extracting by means of FFT 4. Feature extractors FFT use gives well-separable vectors of class features, As it is shown in [9], the use of images in their original but the described algorithm has a number of form is ineffective within the classification task. The disadvantages. First, FFT calculating is quite resource- largest amount of data about the surface type in a photo is intensive, especially against LTP background. The second provided by patterns in its structure. To obtain these feature is the peculiarity of the obtained vector for an patterns special algorithms are used that is feature image segment – for example, it is sufficient to calculate extractors [5]. The best-known feature extractors include LTP once for the entire image. artificial neural networks, algorithms based on Fourier The result of applying LBP operator to the pixel matrix transformations and so-called descriptors of key points. is a response matrix of values that characterize the Fourier transformation described above also has a brightness distribution in the neighborhood of the central discrete form that is suitable for digital image processing: pixel – the so-called bins. Based on the bin matrix, you can build an image histogram, which, unlike the brightness (2) , histogram, does not characterize the color distribution, but the image structure (Fig. 4). (3) , where: − 𝑋𝑋𝑘𝑘 is the transformation result; Fig. 4. Getting image histogram Based on this, the task of searching for a forest on an image of the earth's surface can be done by calculating LBP histogram in the window mode and comparing it with the standard. Another way to reduce the impact of noise, as well as to eliminate some of the texture details, is to introduce a threshold value 𝑇𝑇 in the indicator condition. In this case, you can set three different values when building the code, taking into account the sign of the difference between the central pixel and neighboring ones. This method was presented under the name "local ternary pattern" (LTP). In order to avoid an increase in the space of features, LTP is divided into two parts – the positive and negative patterns (Fig.5). Fig. 7. Clustering algorithm, where lbpr is LBP histogram with the size w×h; ws is window size; tr is threshold To preserve the possibility of comparing classification Fig. 5. Local ternary pattern results with similar ones based on BPF coefficients, it was decided to process squares with a side length equal to The dimension of basic LBP result can be reduced in number "2", which follows from the requirements of two specific ways – using only so-called uniform patterns BDPF algorithm. According to the requirements, the or patterns that are not sensitive to rotation of the pixel window size range 16×16 – 32×32 was selected. If the neighborhood. window size is more than 32×32, the number of arithmetic Some binary codes have more information than others. operations per pixel becomes critical. Since the area of the Thus, a local binary pattern is called uniform if it contains common pine crown, on the basis of which some of the no more than three series of "0" and "1" [7,11]. Uniform main comparisons are made, is 8-10 square meters, 16×16 LBPs define only important local features of the image, segment completely covers from 1 to 4 adult trees, which such as line ends, faces, corners, and spots (Fig. 6), and still allows to cover several trees in a sliding window. also provide significant memory savings, i.e. the set of The texture of the forest is heterogeneous, but the pattern s is reduced from 2𝑝𝑝 to (𝑃𝑃(𝑃𝑃 − 1) + 2. selection of multiple clusters for a forest area is the second condition for applying feature extractor, since one of the tasks being solved in the current work is the selection of forest stands of different species. The basic condition is a clear separation of the forest from other types of terrain. Since there is no need to allocate full-fledged clusters, so Fig. 6. Example of local features detected by LBP the simplest algorithm is used – clusters are allocated by a 5. Selection of algorithm characteristics specified threshold, and the first pattern belonging to the cluster is used as the cluster kernel. The maximum window scale was selected as 1m/px, For comparison of texture patterns it is necessary to which corresponds to the capabilities of most types of introduce a separability measure. There are many modern satellite cameras [2] and makes it easier to link to separability measures such as Euclidean distance, city the metric area. block distance, divergence, and many others [2]. The most The simplest way to determine the separability of common measure in machine learning problems is forest texture classes is to cluster text images and then Euclidean distance, i.e. the distance between two points in evaluate the result (Fig. 7). n-dimensional space [2,12]. Euclidean distance does not take into account the overlap of class distributions and is not applicable at a low level of separability (Fig.8), but there are modifications of this measure that eliminate its indistinguishable. At threshold of 14, the forest, detached disadvantages. One of these modifications is Mahalanobis trees and buildings of the village are clearly measure. distinguishable, but they are indistinguishable from trees. At the threshold of 50, only lake bridges and part of the road could be identified. Fig. 10. LTP allocation for various threshold values Fig. 8. Types of class separability [2] 6. Classification tools Application of Mahalanobis measure makes sense for After pre-processing the image and subsequent classification, but not for clustering, since the covariance selection of feature vectors, it is necessary to determine matrix is calculated based on a training set for a class that whether these vectors belong to any type of terrain, that is, does not yet exist. to classify them. Classifying an object means specifying One pixel is considered as a clustering unit. A certain the number of the class that this object belongs to. area is captured around the pixel, for which a histogram is Previously described similarity measures - built and compared with standards. The cluster index is Mahalanobis distance and Euclidean distances - can be assigned to the center pixel. 17×17 b 33×33 are chosen as used to classify feature vectors based on standards, which window sizes, according to the data provided above, was demonstrated when describing threshold clustering. approximately one and four trees per window. This algorithm is easy to implement and to be scaled, but In the course of checking the separability of classes, it the linear dependence of the speed on the number of was found that regardless of the algorithm characteristics reference vectors makes it unacceptable within the for extracting features, structural features for different framework of the described system. types of terrain can be almost indistinguishable. Fig.9 There are many classification algorithms, and choosing shows the result of selecting the threshold. a specific one is not an easy task. Determining the suitability of the classifier for working with the data formats used requires, at a minimum, the possibility to implement it for the selected development tools. Making up training and test samples if there are no ready-made ones freely available is a long and time- consuming process. Taking into account mentioned above, three classifiers with different specific features were selected based on the studied references. The first is a naive Bayes classifier for implementing a search based on a set of small classifiers. The second is a decision tree for optimizing classification based on similarity measures. The third is a multi-layer perceptron for processing large samples of data accumulated during the operation of the system. Since the Fig. 9. Clustering results for window 33×33 perceptron was not fully introduced into the system, there is no description of it. All the algorithms managed the task to some extent. LBP could not identify the forest, but it accurately 7. Naive Bayes classifier identified the transitions between the main types of terrain. Naive Bayes classifier (NBC) is a simple probability CSLBP and MLBP were able to separate the forest, while classifier based on Bayes theorem: failing to separate the texture of the forest from that of the vegetable gardens. With the help of ULBP, it was possible (6) to identify the main contours of forest stands, but the where: 𝐶𝐶𝑘𝑘 – 𝑘𝑘-class; 𝑋𝑋 = (𝑥𝑥1, 𝑥𝑥2, … , 𝑥𝑥𝑛𝑛) is a size feature border lines (forest/field, forest/clearing) were excluded. vector 𝑛𝑛; 𝑝𝑝(𝐶𝐶𝑘𝑘 ∨ 𝑋𝑋) is conditional (a posteriori) probability The best result was achieved using LTP method, which of belonging 𝑋𝑋 to class 𝐶𝐶𝑘𝑘; 𝑝𝑝(𝑋𝑋 ∨ 𝐶𝐶𝑘𝑘) is conditional accurately marked the contours of the forest and thickets probability to find vector 𝑋𝑋 in class 𝐶𝐶𝑘𝑘; 𝑝𝑝(𝐶𝐶𝑘𝑘) is near the road, while selecting them in one cluster with the unconditional (a priori) probability to meet class 𝐶𝐶𝑘𝑘; 𝑝𝑝(𝑋𝑋) buildings of the village. is the probability of availability of vector 𝑋𝑋 in the training Unlike other methods, LTP can be directly configured sample. without using filters, binarization, etc. Fig. 10 shows the The classifier is called "naive", because for an results of LTP allocation for various threshold values. At available set of features, it is assumed that the distribution the threshold of 0, the terrain types are almost of their values is independent of each other. Despite this simplification, NBC in many cases shows itself no worse on the basis of which the edit distance cannot be than more complex classifiers [5]. calculated. However, they can also be reduced to binary Since all vectors are represented in the sample with attributes by setting requirements for the values of features probability 1, the original formula is simplified to: – if a > n, then class A, and so on. In this case, the vector 𝑝𝑝(𝐶𝐶𝑘𝑘 ∨ 𝑋𝑋) = 𝑝𝑝(𝑋𝑋 ∨ 𝐶𝐶𝑘𝑘) ∙ is simplified to a binary tree and comes into compliance (7) 𝑝𝑝(𝐶𝐶𝑘𝑘), with another common classification algorithm – the Given that the possible dependence of the probabilities decision tree. of features occurring is not taken into account, (𝑋𝑋 ∨ 𝐶𝐶𝑘𝑘) is The decision tree training consists of selecting nodes calculated as the product of the probabilities of all features: based on a training sample, each of which is characterized by a feature vector attribute that most affects the outcome (8) of the classification stage [6]. Node splitting occurs until To work with features-vectors of values, there is a the threshold probability is reached when the output value will take the required value. modification of the classifier, that is, the so-called In general, the condition for reaching these aims at i- Gaussian naive Bayes classifier (GNBC). Gaussian distribution is also called the normal level can be represented as follows [6]: distribution. The normal distribution graph is a bell-shaped 𝐶𝐶𝐶𝐶 = (𝑄𝑄11 ∨ 𝑄𝑄12 ∨ … 𝑄𝑄1𝑘𝑘) curve that is symmetrical with regard to the average value ∧ (9) (Fig. 11). (𝑄𝑄21 ∨ 𝑄𝑄22 ∨ … 𝑄𝑄2𝑘𝑘) ∧ … ∧ (𝑄𝑄𝑄𝑄1 ∨ 𝑄𝑄𝑄𝑄2 ∨ … 𝑄𝑄𝑄𝑄𝑄𝑄), where: 𝑄𝑄𝑄𝑄𝑄𝑄 is logical required condition; 𝑖𝑖 is a node level; 𝑘𝑘 is the number of conditions. Since the process is organized on the basis of reference feature vectors, the last node may hide a set of such vectors. At the same time, passing the tree to the end does not guarantee that the sample belongs to the described classes. At the final stage it is compared with the standards using Mahalanobis distance described earlier, which is Fig. 11. Normal distribution graph used to make a conclusion about (not)belonging to the Due to the fact that to calculate the standard deviation, class. Covariance matrix is calculated for each class it is necessary to recalculate the mathematical expectations separately. of features again (the mathematical expectation can be Fig. 12 shows the tree structure. calculated based on the previous value, as opposed to 𝜎𝜎), NBС cannot be further trained in the course of work. Given the method of determining a priori probability, an important condition for correct NBC training is the statistical correspondence of the training sample composition to the composition of the studied data. 8. Decision tree The task of monitoring the dynamics of changes in the Fig. 12. Structure of hybrid decision tree forest area involves processing large amounts of information over a long period of time. This process The advantage of the described algorithm is its high actively uses classification tools, and it may be necessary speed of relatively simple searching [6]. It is important to to adjust the classifiers for different tasks. Training a note that using a covariance matrix makes it impossible to classifier is a rather time-consuming process, since the update instantly during operation – features are added to main criterion for its success is the quality and volume of the tree, but the matrix can only be recalculated in the the training sample, which must be collected and provided background process. with appropriate markers. To simplify this task, the system saves vectors of reference features and their source images 9. Classification scenario to the database. This approach allows not only to reuse prepared class maps, but also organize classification based Previously, the advantage of using multiple algorithms on the database without training. Classification based on for distinguishing features or classifying them together has the feature vector library belongs to the group of been demonstrated. Not for all classification algorithms a classification methods based on comparison with the non-uniform feature vector can be created. For example, standard [8]. The method of comparison with the standard when classifying by similarity, it is not possible to use LBP involves the construction of a graph of feature vectors, and the average values of RGB spectrum together, because while the classification process means finding the shortest LBP will give two hundred features, and the spectrum will path, which is based on the concept of edit distance – the give three features, which will have negligible effect on minimum number of changes, inserts and losses required the result. To solve such problems, the concept of a to change the image of A to the image of B [8]. The feature classification/search scenario was formed (Fig. 13). extractors described earlier give vectors of real numbers, values around the average will be S2+(S2/n), where 𝑆𝑆 is the standard deviation. To predict borders, outlines are initially selected – the image pixels are bypassed in the cycle, the border pixels are found, and the array is saved. Then the array is bypassed and a segment is added for pixels whose distance is greater than the threshold (Fig. 15). Fig. 15. Separating boundaries After selection, the formula described is applied to the obtained points (junctions of segments). The shortest of Fig. 13. Scheme of classification scenario the three segments is chosen as the direction of extrapolation -two to the two nearest previous points, and Classification scenario is a data structure that specifies the third is the median of the resulting triangle (Fig. 16). the order in which images are processed by multiple algorithms. The resulting class maps are combined using logical operations. The scenario can also be used to describe one-dimensional algorithms. For example, the following selection of trees according to the scenario "median filter" - "spot selection (LBP)" - "center filtering". Fig. 16. Prediction of changes in boundaries by one step 10. Prediction of changes in the boundaries Changes in forest boundaries can be caused by many 11. Conclusions factors, many of which are random. Events such as fires, Within the framework of this paper, a number of deforestation, and disease outbreaks lead to rapid changes algorithms for processing and classifying graphical in the structure of plantings, with no pronounced information were proposed to solve the tasks of studying periodicity. forest stands based on images of the earth's surface. Fig. 14 shows the boundary changes that need to be LTP and FFT algorithms were selected as feature taken into account when developing the algorithm. extractors, of which the simplest and most productive option is LTP, and the most complete and at the same time resource–intensive is FFT. To pre-process the image, histogram equalization algorithms, median and Gaussian filters to eliminate noise and remove small image details were selected. Fig. 14. Basic scenarios of boundary changes Euclidean distance was used as a measure of separability, Mahalanobis measure - for the purpose of Predicting function values with reference to a time classification. Czekanowski's quantitative index is also interval requires the use of one-factor forecasting available in the system, which gives results similar to functions [8], but in the absence of a large sample, Euclidean distance, but with a different distribution of debugging such a solution is not possible. If we reduce the output quantities. complexity of requirements for the forecast, methods that For classification, it was proposed to use a naive Bayes are easier to implement and debug become available, such classifier, a simple but effective statistical classifier based as step-by-step extrapolation, where the time interval is the on Bayes theorem. As a less specialized classifier that interval between sample events. works without training on the basis of features stored in Under the assumption that the average level of the the database, the decision tree algorithm was proposed, an series has little tendency to change, we can assume that the algorithm that significantly speeds up classification based predicted level is equal to the average value of the levels on comparison with the standard by organizing feature in the past [8]. vectors into a binary tree. A three-layer perceptron was The confidence limits for the average with a small also proposed as a test solution for working with large number of observations are defined as follows: samples, but it was not possible to test it fully due to the (10) large amount of training sample required. where 𝑡𝑡𝑎𝑎 is the table value t of Student statistic with n-1 These algorithms were described and tested. On their degree and probability level 𝑆𝑆𝑦𝑦. basis a set of libraries in C# language was developed, The total variance associated with both the fluctuation which form the described system together. MongoDB was of the sample average and the variation of individual chosen as the database, which is easy to develop and quite high – performance database that uses BSON documents as a storage format. A web service based on Asp.Net.Core was developed to provide shared access to the system's About the authors tools. Its organization features are described in the project Alexandr A. Kuzmenko, Bryansk State Technical part. University, Bryansk, Russia. E-mail: alex-rf-32@yandex.ru Dmitriy A. Kondrashov, Bryansk State Technical University, References Bryansk, Russia. E-mail: kuzmenko-alexandr@yandex.ru [1] Moiseev N.A. On the state of forest use and the need Anna S. Sazonova, Bryansk State Technical University, to improve forest management. Forestry Bulletin, Bryansk, Russia. E-mail: asazonova@list.ru Ludmila B. Filippova, Bryansk State Technical University, 2011, no.7. Bryansk, Russia. E-mail: libv88@mail.ru [2] Farutgin I.N. Technological solutions of ScanEx for Rodion A. Filippov, Bryansk State Technical University, receiving and processing satellite information. Bryansk, Russia. E-mail: redfil@mail.ru Interexpo Geo-Sybir, 2011. pp. 3-5. [3] Forests and land use: solution description. Planet Labs Inc., 2019. Available at: https://www.planet.com/markets/forestry/. [4] Strugailo V.V. Overview of digital image filtering and segmentation methods. Moscow Automobile and Road Construction State Technical University. pp. 270–281. [5] Kolesenkov A.N. Monitoring of subsurface use processes based on processing of aerospace images. Izvestiya TulGU Technical Sciences, 2018, no. 2. [6] Evdokimova N.I. Local patterns in the duplicate detection task. Computer Optics, 2017, vol. 41, no. 1. pp. 79-87 . [7] Polovinkin P.N. Detectors and descriptors of key points. Image classification algorithms. The problem of detecting objects in images and methods for solving it. Lobachevsky State University of Nizhni Novgorod. 30 p. [8] Olsen, R.C., S. Bergman, and R.G. Resmini. Target detection in a forest environment using spectral imagery. SPIE 3118:4b, 1997. [9] Ed. By Prasard S. Thenkabail, John G.Lyon, Alfredo Huete. Hiperspectral remote sensing of vegetation. – CRC Press, 2012. [10] Filippov R.A. Internet of things: basic concepts: Tutorial. Bryansk, BSTU, 2016. 112 p. ISBN 978-5- 906967-62-6. [11] Averchenkov A.V. Development of a mathematical model of an information system for inventory and monitoring of software and hardware based on fuzzy logic methods. Kachestvo. Innovatsii. Obrazovaniye., 2018, no.7. pp. 105-112. ISSN: 1999-513X [12] Leonov, Yu.A. Selection of rational schemes automation based on working synthesis instruments for technological processes/ YU.A. Leonov, E.A. Leonov, A.A. Kuzmenko, A.A. Martynenko , E.E. Averchenkova, R.A. Filippov - Yelm, WA, USA: Science Book Publishing House LLC, 2019 - 192 p. - ISBN: 978-5-9765-4023-1 - Text : unmediated. [13] Leonov E.A., Intellectual subsystems for collecting information from the internet to create knowledge bases for self-learning systems / E.A. Leonov, Y.A. Leonov, Y.M. Kazakov, L.B. Filippova/ In: Abraham A., Kovalev S., Tarassov V., Snasel V., Vasileva M., Sukhanov A. (eds) - Text : electronic // Proceedings of the Second International Scientific Conference “Intelligent Information Technologies for Industry” (IITI’17). IITI 2017. Advances in Intelligent Systems and Computing. - 2017 - vol 679. - Springer, Cham, p. 95-103 - DOI:10.1007/978-3-319-68321-8_10