Ukrainian Journal of Information Technology
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Published By Lviv Polytechnic National University

2707-1898

2021 ◽  
Vol 3 (2) ◽  
pp. 27-32
Author(s):  
I. M. Fefelova ◽  
◽  
V. I. Lytvynenko ◽  
A. O. Fefelov ◽  
◽  
...  

This work discusses the problem of forecasting the tertiary structure of a protein, based on its primary sequence. The problem is that science, with all its computing power and a set of experimental data, has not learned to build models that describe the process of protein molecule coagulation and predict the tertiary structure of a protein, based on its primary structure. However, it is wrong to assume that nothing is happening in this field of science. The regularities of folding (convolution) of the protein are known, methods for its modelling have been developed. Analysis of the current state of research in the field of these problems indicates the presence of shortcomings associated with the accuracy of forecasting and the time necessary to obtain the optimal solution. Consequently, the development of new computational methods, deprived of these shortcomings, seems relevant. In this work, the authors focused on the lattice model, which is a special case of the known hydrophobic-polar dill. protein conformation according to the chosen model, hybrid algorithms of cloning selection, differential are proposed. Since the processes of protein coagulation have not been fully understood, the researchers proposed several simplified models based on the physical properties of molecules and which leads to problems of combinatorial optimization. A hydrophobic-polar simplified model on the planar triangular lattice is chosen as a protein model. From the point of view of the optimization problem, the problem of protein folding comes down to finding a conformation with minimal energy. In lattice models, the conformation is represented as a non-self-cutting pathway. A hybrid artificial immune system in the form of a combination of clonal selection and differential evolution algorithms is proposed to solve this problem. The paper proposes a hybrid method and algorithm to solve the protein folding problem using the HP model on a planar triangular lattice. In this paper, a hybrid method and algorithm for solving the protein folding problem using the HP model on a planar triangular lattice are proposed. The developed hybrid algorithm uses special methods for encoding and decoding individuals, as well as the affinity function, which allows reducing the number of incorrect conformations (self-cutting solutions). Experimental studies on test hp-sequences were conducted to verify the effectiveness of the algorithm. The results of these experiments showed some advantages of the developed algorithm over other known methods. Experiments have been taught to verify the effectiveness of the proposed approach. The results labelled "Best" show the minimum energy values achieved over 30 runs, while the results labelled "Medium" show the robustness of the algorithm to achieve minima. Regarding robustness, the hybrid algorithm also offers an advantage, showing higher results. A comparative analysis of the performance results of the proposed algorithm on test sequences with similar results of other published methods allows us to conclude the high efficiency of the developed method. In particular, the result is more stable, and, in some cases, conformations with lower energy are obtained. Keywords: protein folding; hydrophobic-polar model; clonal selection; differential evolution; artificial immune systems; hydrophobic-polar model.


2021 ◽  
Vol 3 (2) ◽  
pp. 87-93
Author(s):  
K. M. Berezka ◽  
◽  
O. V. Kneysler ◽  
N. Ya. Spasiv ◽  
H. M. Kulyna ◽  
...  

The purpose of time series modelling is to predict future indicators based on the study and analysis of past and present data. Various time series methods are used for forecasting. The article uses econometric extrapolation research methods. Analyzed scientific works are related to extrapolation methods for forecasting time series. The dynamics of the financial formation related to results of Ukrainian insurance companies by the types of their activities have been analyzed. The main factors that determine the effectiveness are determined. It was found that the most rational approach to short-term forecasting of the financial results of insurers is the use of exponential smoothing. The optimal parameters are selected for the model of exponential smoothing of the first and second order by the method on the grid. The following indicators of the quality of the model were used: the mean value of the standard deviation of the model error to the actual data, Theils coefficient of discrepancy, mean absolute percentage error MARE. The net financial result of the activities of Ukrainian insurers was predicted, the lower and upper bounds of the forecast for 2021 for a reliability level of 0.95. To predict the net financial result of the activities of Ukrainian insurers, statistical data for 10 years from 2011 to 2020 were used, the financial results of the main (insurance and other operating) activities before tax, the results of financial activities before tax, the financial results of other ordinary activities (extraordinary events) before tax, income tax. The prototype of the software module for predicting the financial performance of insurance companies was developed in Statistica and Excel. Forecasting results based on the use of econometric modelling make it possible to identify permanent positive shifts in the domestic insurance market and the activities of insurers on it; to confirm the effectiveness of the adopted strategic and tactical financial decisions of insurance companies; to increase the efficiency of insurers management based on the results of quantitative determination the degree of influence of each factor on the formation of the financial results related to their activities; to identify trends in the development of the situation in the future, to more accurately form a set of measures to maximize profits and minimize costs of insurance companies to ensure guarantees of reliable insurance protection and satisfy the interests of their owners. Keywords: financial results; insurance companies; net financial result; exponential smoothing; time series; econometric forecasting methods.


2021 ◽  
Vol 3 (2) ◽  
pp. 81-86
Author(s):  
O. Yu. Mulesa ◽  
◽  
F. E. Geche ◽  
A. Ye. Batyuk ◽  
O. O. Melnyk ◽  
...  

The study is devoted to the development of information technology for forecasting based on time series. It has been found that it is important to develop new models and forecasting methods to improve the quality of the forecast. Information technology is based on the evolutionary method of synthesis of the forecast scheme grounded on basic forecast models. The selected method allows you to consider any number of predictive models that may belong to different classes. For a given time series, the weight coefficients with which the models are included in the resulting forecast scheme are calculated by finding the solution to the optimization problem. The method of constructing the objective function for the optimization problem in the form of a linear combination of forecasting results by basic forecasting models is shown. It is proposed to find the solution to the optimization problem using a genetic algorithm. The result of the method is the forecast scheme, which is a linear combination of basic forecast models. To assess the quality of the forecast, it is suggested to use forecasting errors or forecast volatility calculated as the standard deviation. Forecast quality criteria are selected depending on the context of the task. The use of forecast volatility as a quality criterion, with repeated use of technology, will reduce the deviation of forecast values from real data. The structural scheme of information technology is developed. Structurally, information technology consists of two blocks: data processing and interpretation of the obtained values. The result of the application of the developed information technology is the production rules for determining the predicted value of the studied quantity. Experimental verification of the obtained results was performed. The problem of forecasting the number of religious organizations in Ukraine based on statistical data from 1997 to 2000 has been solved. The autoregression method and the linear regression model were chosen as the basic forecast models. Based on the results of using the developed information technology, the weights of the basic models were calculated. It is demonstrated that the obtained forecast scheme allowed to improve the average absolute percentage error and forecast volatility in comparison with the selected models. Keywords: information technology; time series; forecasting; evolutionary technologies; forecast volatility; synthesis of the forecast scheme.


2021 ◽  
Vol 3 (2) ◽  
pp. 33-38
Author(s):  
S. P. Stryamets ◽  
◽  
H. V. Striamets ◽  

Forest management involves the use of large areas of land and a large amount of related information. Therefore, the use of geographic information technologies (GIS) is substantiated for the processing, analysis, and visualization of information in forest ecosystems. Green plants and trees deposit carbon and retain it for a long time, they are the main absorbers of carbon on land, so to determine the carbon balance the study of wood growth, accumulation of phytomass in forest ecosystems is necessary. The purpose of the work is to develop a toolkit for determining the geo-distributed phytomass of forests for the calculation of deposited carbon according to statistical data of planting stock, species composition, age class, and other silvicultural and taxonomic indicators provided by the official sources. The article provides a description of Polish forests, GIS analysis of tabular data on taxonomic indicators of forest ecosystems, diagrams, and digital maps of forests. The analysis of the forests state in some voivodships of Poland in 2009 and 2019 was conducted to assess emissions and removals of greenhouse gases by forest ecosystems. The three-level scheme of greenhouse gas inventory recommended by the IPCC technique is described. To carry out the inventory, a multilevel mathematical model is used, which includes: the highest level of inventory (level of national inventory), the middle level of inventory (level of region or district), and the inventory lowest level (level of the elementary plots). A comparative analysis of forestry and tax indicators of Polish forests for the period from 2009 to 2019 and the methods used to calculate greenhouse gas emissions and removals are presented. The amount of carbon deposited over a ten-year period by Polish forest ecosystems has been determined. The architecture of geographic information technology for spatial analysis of carbon deposition and greenhouse gas emissions in the Polish forestry sector has been improved and supplemented. Calculations of the deposited carbon were made according to statistical data of planting stock, species composition, age class, and other silvicultural and taxonomic indicators, which are taken from the official sources. The geoinformation approach to the comparative analysis of greenhouse gases for different time intervals is based on the use of the appropriate digital map layers, mathematical models of inventory, statistical information on business results, as well as the use of a number of other specific parameters describing complex greenhouse gas emission and absorption processes. Keywords: GIS; digital maps; greenhouse gases; forests of Poland.


2021 ◽  
Vol 3 (2) ◽  
pp. 39-44
Author(s):  
Ya. I. Sokolovskyy ◽  
◽  
O. V. Sinkevych ◽  

In this work, we investigated the possibilities of using a model of cellular automata in solving the problem of heat and moisture transfer in a periodic wood drying chamber. Thus, in this work are investigating the processes of heat and moisture transfer between the wood and its drying agent. Studies are carried out by using CAD model of stack of dried wood. To use cellular automata, it is proposed to present the CAD model as an array of cubes, each of which has six faces (cells). In this work also proposes to use the different research zones, each of which allows us to calculate the values of temperature and moisture content in different places of the CAD model. In particular, these zones can be placed inside the wood, on its boundary or in the agent of its drying. The proposed cell-automata model contains local relationships between cells that describe their general behavior. In addition to describing the general behavior of cells, the model provides the possibility of setting the physical characteristics of the material. This allows us to approximate processes and determine new values of the physical characteristics of the material, including temperature and moisture content. The proposed algorithm for the use of cellular automata makes it possible to obtain a reliable result unnecessarily to conduct complex and expensive practical experiments. To speed up the calculation process, propose to use multilayered, which consists in obtaining numerical values of the physical characteristics of the material from several adjacent cells, which are located in the same direction of interaction. The work also provides graphs of changes in temperature and relative humidity of the wood drying agent. In this work is also given graphs of changes in temperature and moisture content of wood inside and on its boundary. To check the adequacy and reliability, all results are compared with the results of another experiment. To check the adequacy and reliability, we compared the obtained results with the results of another experiment. For this comparison in work it is calculated the relative error between the temperature and moisture content values of both experiments. The value of this relative error makes it possible to determine the prospects for the use of cellular automata in the simulation of heat and moisture transfer processes in wood drying chambers. Keywords: сellular automata; CAD model; algorithm of work; transition rules; wood drying chamber.


2021 ◽  
Vol 3 (2) ◽  
pp. 58-65
Author(s):  
Ya. R. Sovyn ◽  
◽  
V. V. Khoma ◽  

The article is devoted to the issues of increasing the security and efficiency of software implementation for the symmetric block ciphers. For the implementation of cryptoalgorithms on low-end CPUs (8/16/32-bit microcontrollers), it is important to provide increased resistance to power consumption analysis attacks. With regard to the implementation of ciphers on high-end CPUs (x86, ARM Cortex-A), it is important to eliminate the vulnerability primarily to timing and cache attacks. The authors used a bitslice approach to securely implement block ciphers, which has potential advantages such as high speed and low computing resources. However, the known bitsliced methods have a significant limitation, since they work with deterministic S-Boxes or arbitrary S-Boxes of smaller sizes. The paper proposes a new heuristic method for bitsliced representation of cryptographic 8×8 S-Boxes containing randomly generated values. These values defy description using algebraic expressions. The method is based on the decomposition of the truth table, which describes the S-Box, into two parts. One part of the table forms logical masks, and the other is split into bit vectors. To find a logical description of these vectors an exhaustive search is used. After finding the description of all vectors, these two parts of the table are combined into one using logical operations. The use of this method oriented on software implementation in the logical basis {AND, OR, XOR, NOT} ensures the minimization of arbitrary 8×8 S-Boxes. The proposed method can be implemented using standard logical instructions on any 8/16/32/64-bit processors. It is also possible to use logical SIMD instructions from the SSE, AVX, AVX-512 extensions for x86-64 processors, which provides high performance due to the use of long registers. The corresponding software has been developed that implements the method of searching for bitsliced representations of a given S-Box, and also automatically generates C++ code for it based on SSE, AVX and AVX-512 instructions. The effectiveness of the method on the S-Box of known block ciphers, in particular the Ukrainian encryption standard "Kalyna", has been investigated. It was found that the developed algorithm requires almost half as many gates for the bitsliced description of an arbitrary S-Box than the best of known algorithm (370 gates versus 680, respectively). For ciphers that use two or four S-Box tables, joint minimization can yield up to 330 or 300 gates per table, respectively. Keywords: bitslicing; S-Box; logical minimization; SIMD; x86-64 CPU; software implementation; block ciphers.


2021 ◽  
Vol 3 (2) ◽  
pp. 45-50
Author(s):  
I. G. Tsmots ◽  
◽  
O. Ya. Riznyk ◽  
B. I. Balych ◽  
Ch. Z. Lvovskij ◽  
...  

Noise immunity is one of the essential characteristics of modern wireless data reception/transmission systems. In wireless systems such as Wi-Fi, HiperLan, or Bluetooth, the signal is propagated by electromagnetic oscillations in the environment. However, unlike wiring systems, these oscillations are unprotected from external influences. Noise immunity is one of the essential characteristics of modern wireless data reception/transmission systems. Moreover, if several wireless systems work close enough to each other, there is a possibility of overlapping waves, which will damage the information signal. It is determined that for the tasks of control of unmanned aerial vehicles and mobile robotic complexes increasing the noise immunity of data transmission channels is an urgent problem. It has been investigated that Barker-like code sequences based on ideal ring bundles provide an increase in the power of the obtained sequences by optimizing the parameters of the ideal ring bundles used. It is determined that the increase of noise immunity during data reception and transmission is achieved by choosing the optimal ratios of the parameters of the ideal ring bundle. It is shown that the advantages of Barker-like code sequences such as the optimal ratio between the length of the sequence and its correcting ability, the ability to change the length of the sequence depending on the level of interference are widely used in modern wireless communication and telecommunications systems. The method of synthesis of Barker-like code sequences with the use of ideal ring bundles has been improved, which, by taking into account the ratios of the parameters of ideal ring bundles, provides the choice of the minimum bit code sequence that takes into account the level of interference. A simulation model of synthesis of Barker-like code sequences, noise generation, and error correction has been developed on the basis of the improved method of synthesis of Barker-like code sequences. The developed simulation model is used to study the processes of coding, decoding, detection, and correction of errors in the obtained Barker-like code sequences. It has been investigated that the use of synthesized Barker-like code sequences based on ideal ring bundles provides data recovery of damaged no more than 25 % of the bits of each codeword, and detects up to 50 % of damaged bits in each codeword. Keywords: Barker-like code sequence; ideal ring bundle; noise-tolerant coding; simulation model.


2021 ◽  
Vol 3 (2) ◽  
pp. 01-14
Author(s):  
T. P. Diak ◽  
◽  
Yu. I. Hrytsiuk ◽  

Features of designing a system of automated generation of poetic works, which opens up new opportunities for artistic speech and show business, especially the preparation of poems and songs have been considered. Quite often lyrics without special content become successful due to the lack of complex plots, as well as due to the unobtrusiveness and ease of perception by listeners. Well-known literature sources and available software products that can generate poetic works by combining different methods and algorithms are analyzed. It has been established that none of them is able to ensure the content and uniqueness of the poetic work at the same time, especially in the Ukrainian language. The existing approaches to the generation of poetic works are analysed, among which the relevant is a method based on templates, generation and testing, evolutionary algorithms and the method based on specific cases. Peculiarities of generating poetical works, first of all rhyming rules, types of strophes, poetic rhythms and sizes have been investigated. An approach to automated generation of poetic works using evolutionary algorithms and a method based on specific cases have been developed. Their combination resembles a sequence of actions for creative personalities when creating poems or writing lyrics. Peculiarities of neural network organization for automated generation of poetic works have been considered. It is proposed to perform neural network training using the method of inverse propagation and using a genetic algorithm. The principle of operation of algorithms for finding optimal solutions which contain such consecutive stages as initialization, evaluation of solutions, population selection, evolution of solutions, is analysed. Their interaction and various opportunities for neural network learning have been investigated in detail. An algorithm has been developed according to which the software application will analyse the poetic works offered by the user and generate new variants of it on the basis received from the neural network of logically connected words or lines of the verse in the poem. The user can edit both the components of the poem and the generated poetic works, and thus can train the neural network. The specification of requirements to the software application has been developed, the basic requirements to the user interface are defined, and also potential classes of users who will use it are established. Keywords: computational linguistics; Artificial Intelligence; neural network; genetic algorithm; optimal solution.


2021 ◽  
Vol 3 (2) ◽  
pp. 74-80
Author(s):  
I. G. Tsmots ◽  
◽  
V. M. Teslyuk ◽  
Yu. V. Opotiak ◽  
R. V. Parcei ◽  
...  

The requirements for a mobile robotic platform (MRP) with an intelligent traffic control system and data transmission protection are determined. Main requirements are the reduction of dimensions, energy consumption, and cost; remote and intelligent autonomous traffic control; real-time cryptographic data protection; preservation of working capacity in the conditions of action of external factors; adaptation to customer requirements; ability to perform tasks independently in conditions of uncertainty of the external environment. It is proposed to develop a mobile robotic platform based on an integrated approach including: navigation methods, methods of pre-processing and image recognition; modern methods and algorithms of intelligent control, artificial neural networks, and fuzzy logic; neuro-like methods of cryptographic data transmission protection; modern components and modern element base; methods of intellectual processing and evaluation of data from sensors in the conditions of interference and incomplete information; methods and means of automated design of MRP hardware and software. The following principles were chosen for the development of a mobile robotic platform with an intelligent control system and cryptographic protection of data transmission: hierarchical construction of an intelligent control system; systematicity; variable composition of equipment; modularity; software openness; compatibility; specialization and adaptation of hardware and software to the structure of algorithms for data processing and protection; use of a set of basic design solutions. The basic architecture of a mobile robotic platform with an intelligent traffic control system and data transmission protection has been developed, which is the basis for the construction of mobile robotic platforms with specified technical and operational parameters. To implement neuro-like tools, the method of tabular-algorithmic calculation of the scalar product was improved, which due to the simultaneous formation of k macroparticle products provides k times reduction of the time of the scalar product calculation. Keywords: mobile robotic platform; intelligent processing; architecture; neural network; autonomous control; sensors; data protection.


2021 ◽  
Vol 3 (2) ◽  
pp. 15-20
Author(s):  
D. V. Rudavsʹkyy ◽  
◽  
M. S. Shefer ◽  
Yu. I. Kanyuk ◽  
Z. Ya. Shpak ◽  
...  

The reliability and safe operation of mechanical elements of rail transport is an important and relevant scientific and technical issue since high-loaded units and elements of its chassis are exposed to prolonged operation and their failure can lead to damage with catastrophic consequences. To prevent the possible failure of such objects, there is a necessity for a reliable estimation of their residual life. Among the cast parts of the freight car trolley, the side frames are one of the most loaded elements, which take on dynamic loads that cause vibrations of the unsprung parts of the freight car. The side frame of the 18-100 trolley, as a typical representative of a number of trolleys of freight cars, does not have a sufficient margin of resistance to fatigue and survivability, so it is sensitive to some deviations and defects (different wall thickness, sinks, and pores, residual stresses) that are detected during the operation process. Based on the energy approach of the mechanics of materials fatigue failure, the calculation models for estimating the dynamics of the development of crack-like defects under the action of operational load are developed in this work. The calculation models constructed using modern information technologies, and the software developed for their numerical implementation allow predicting the impact of irregular cyclic loading and complex stress on the growth of surface fatigue crack in the side frame of the carriage, which significantly brings the problem closer to real operating conditions. Numerical calculations were performed using a computer program of our own development in the Python programming language. At the first stage of the program functioning the spectrum of amplitudes of irregular cyclic loading is built, at the second - the program module of numerical solution construction for systems of usual differential equations of the proposed mathematical model of fatigue defect development is started. Calculations of the fatigue crack growth dynamics taking into account the action of shear stresses in the section with the crack of the side frame showed a slight effect of shear stresses on the residual durability of the frame. It is demonstrated that the dynamics of surface crack development significantly depend on its initial geometry. The proposed calculation method for determining the initial shape of the surface crack with a minimum period to critical growth can be effectively used to predict the residual durability during the technical diagnosis of the running gear parts of railway rolling stock. Keywords: wagon side frame; fatigue crack; probability distribution function; load amplitude spectrum; numerical method.


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