Software & Systems

Articles of journal № 3 at 2021 year.

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1. Performance comparison of proactive routing protocols in VANET based on NS3 [№3 за 2021 год]
Authors: Amani A. Sabbagh, M.V. Shcherbakov
Visitors: 2106
Routing protocols play a major role in computer networks in order to direct data from the source to the target using the least possible network resources available and in the least possible time by choosing the best path for this data. Therefore, researchers continuously develop these protocols in order to reach the network to the best possible performance. The purpose of the study is to evaluate the performance of the routing protocols responsible for transferring data between nodes and their impact on the performance of VANETs using advanced simu-lations that simulate the environment and produce near-real results to reduce high evaluation costs. The change rate is the main problem for researchers to face in VANET networks when developing ap-propriate protocols to meet the requirements of stable operation with a constant change in the number of nodes and the speed of these nodes. Therefore, it is reasonable to experiment with traditional proto-cols to determine the best ones, and then look forward to their further development in the future. Therefore, one of the main research objectives is to determine the appropriate routing protocol for VANETs in order to have a safe traffic environment. The paper analyses the impact of network size at a large number of nodes and different vehicle speeds on network performance metrics like packet deliv-ery ratio, throughput, average delay, overhead and packet loss ratio and assesses the level of network performance at realistic mobility scenarios for vehicle movement in the street generated by Bonnmo-tion tool. The paper selects two routing protocols in VANET networks, namely Destination Sequenced Dis-tance Vector (DSDV) and Optimized Link State Routing (OLSR). Also, the simulation is carried out in NS3 simulator to create VANET network topology and routing protocols. Based on the results, it is es-tablished that OLSR is more efficient than DSDV in VANET networks when the number of nodes in-creases.

2. Approaches to providing data visualization on devices using modern real time operating systems [№3 за 2021 год]
Authors: P.S. Bazhenov , Giatsintov A.M., Mamrosenko K.A.
Visitors: 3584
The paper considers various approaches to developing display controller driver software for embedded systems, which usually use System-on-chip (SOC) solutions and real-time operating systems (RTOS). It also describes the main principles and design decisions of the chosen RTOS, such as portability, flexi-ble scheduling, responsiveness, etc., as well as used standards (C language, POSIX 1003.1, ARINC 653). The authors list general operating principles of the display controller hardware including support for several displays and overlays that can be used for displaying multiple video streams on one screen or achieving the effect similar to chroma keying. The proposed method for developing display controller drivers defines the main parameters of the display controller hardware and the steps necessary to show an image on a screen correctly. The meth-od also takes into account the features related to using hardware interrupts and estimating the frequen-cy required for display controller to show an image on a screen correctly with the defined screen mode. Contrary to the known methods, the proposed method takes into account various features of the many real-time operating systems: lack of dedicated API to interact with graphics hardware and resources, seamless access to hardware registers from user space and so on. The paper considers several ap-proaches to debugging software on the target hardware as well as using prototyping systems based on FPGA. Prototyping systems usually introduce additional challenges to debugging, such as low simula-tion speed. The proposed method was tested during the development of the display controller driver for the home made RTOS, specifically – an X Window System display driver.

3. Intelligent decision support in expert systems in the diagnosis of oral cavity diseases [№3 за 2021 год]
Authors: Burdo G.B., Semenov N.A., Lebedev S.N., Lebedeva Yu.V.
Visitors: 3016
Nowadays, the efforts of the world medicine focus on the early diagnosis of various oncological dis-eases. The situation is complicated by the fact that the provision of high-quality advisory medical care to such patients at the place of residence (rural areas, district cities) is not always possible due to the lack of doctors with the necessary qualifications. For example, even in the central part of Russia, spe-cialized oncological institutions are located only in regional centers. According to the authors, one of the approaches to expanding qualified dental care may consist in the development of an expert system (including remote access) that synthesizes the experience of di-agnosing this group of diseases. Expert systems are more commonly used in various medicine branch-es. Their implementation is also very promising in terms of intensive development of telemedicine. If there are no serious methodological and technical problems when studying the results of examinations, then certain problems appear when determining the tactics of patient management developed during the dialogue of several expert doctors. This paper proposes a method for obtaining a coordinated decision of doctors on the tactics of treat-ing a patient. The method is implemented based on the fuzzy sets device. It is simple and does not re-quire special knowledge from doctors in the field of intelligent systems. The implementation of this method will allow practitioners to obtain informed and balanced deci-sions that summarize the collective knowledge of doctors that increases their accuracy. Naturally, such decisions can be considered as a kind of hint to a doctor and not as an alternative option. As the system functions, the models will be refined, which will increase the expert system efficiency.

4. An approach to modeling the functioning of interdependent energy systems under disturbances and its software support [№3 за 2021 год]
Authors: Edelev А.V., Beresneva N.M.
Visitors: 3385
The purpose of the study is to develop an approach to modeling the functioning of interconnected en-ergy systems under disturbance conditions, which has a universal character in relation to different classes of disturbances and energy complexes of different levels of the territorial hierarchy. The relevance of the work is determined by the need to ensure the energy sector sustainable func-tioning affected by various disturbances ranging from high fluctuations in energy prices and worsening weather conditions up to large-scale natural disasters and man-made disasters. The novelty of the approach in comparison with others is its focus on using high-performance com-puting to speed up calculations and to divide the energy infrastructure model into structural and func-tional parts. The structural part represents the infrastructure topology in the form of a network. The functional part describes the distribution of energy flows across the infrastructure and its response to the impact of disturbances. The division of the energy infrastructure model into structural and functional parts is a fundamental principle in modeling not only energy systems, but also energy complexes, which are con-sidered as metasystems of interconnected energy systems in the proposed approach. The energy complex model is built by combining the structural and functional parts of the models of individual energy systems based on predetermined relationships between them. The universal nature of the proposed approach is also supported by its software implementation using the meta-programming tools of the C++ language, which significantly saves time when creating software packag-es designed to assess the adaptability of energy complexes. The paper demonstrates the application of the approach on the development of a country's energy model that is used in a distributed package of applied programs for global or spatial analysis of vulner-ability, search for critical elements of the energy complex.

5. Software implementation of the data mining module based on case-based reasoning for distributed intelligent systems [№3 за 2021 год]
Authors: Eremeev, A.P. , Varshavskiy P.R., Polyakov S.A.
Visitors: 3957
The paper discusses the problems of implementing the Case-Based Reasoning (CBR) module that al-lows performing all stages of the case-based learning cycle (CBR-cycle) for distributed intelligent sys-tems. Nowadays, there is a steady trend towards widespread using of methods and tools for data mining (DM) for solving various applied problems. More and more large companies are using intelligent sys-tems and DM tools to improve their business efficiency and reduce costs. Due to developing Internet technologies and the availability of cloud computing, a promising direction in the field of artificial in-telligence (AI) is the creation of distributed intelligent systems (DIS). DIS systems are characterized by the distribution of computing and information resources, which increases adaptability, reliability, as well as the overall performance of the system due to the ability to simultaneously process large data sets. DIS systems consist of autonomous nodes (agents) that can act independently and exchange information with each other asynchronously. Since there are agents capa-ble of implementing certain intelligent functions, this is an indication of the close connection between DIS systems and multi-agent systems (MAS). The work focuses on one of the DM methods based on the use of previously accumulated experi-ence (cases). The indicated case method (CBR-method) allows solving a new problem using (adopting) the solution of a similar and already known problem. To solve data analysis problems based on cases, there is a modular case system (CBR-module) that implements the main stages of the CBR-cycle. The implemented system allows working with cases presented in a parametric and structured (based on on-tologies) form. The CBR-module is a web application implemented in the Python 3.7.5 programming language using the Flask web framework and the Owlready2 library to work with ontologies. The de-veloped CBR-module focuses on integrating into a DIS system to perform data mining based on cases. The implemented CBR-module has been tested on the example of solving the classification task us-ing data sets taken from the open repository of the University of California (UCI Machine Learning Re-pository).

6. Methods for accelerating the preparation and embedding of a digital watermark using mobile devices based on Arnold and wavelet transforms [№3 за 2021 год]
Authors: Zotin A.G., Proskurin A.V.
Visitors: 3786
In recent years, digital watermarking technology has become increasingly important due to the explo-sive growth of data transmitted through unprotected communication channels. Digital watermarks can reduce the amount of transmitted information and be used to protect images (hosts) from illegal use. For a more effective implementation of the latter task, various studies are being carried out in order to improve robustness, imperceptibility and security of the watermark. In most cases, this leads to an in-crease in computational costs, which makes it difficult to use digital watermarking in mobile devices. This work proposes several ways to reduce computational costs and computation time of digital wa-termarking methods based on Arnold and wavelet transforms. The first way consists in linear interpre-tation of digital watermark and a host, so it avoids the use of double cycles. The second way is to use lookup tables (LUT) to replace direct calculations. One of these tables allows performing the Arnold transform in certain time regardless of the number of iterations. Iterations for each block are deter-mined using hash code of the secret key and specially formed tables. The third way of digital water-marks embedding time reduction is multithreaded execution implemented using the OpenMP technolo-gy. In combination with linear interpretation, this results in accelerations of 1.90, 2.56 and 3.01 times for two, three and four threads, respectively.

7. The method of constructing software for military simulation complexes [№3 за 2021 год]
Author: Kostrov А.S.
Visitors: 2989
Nowadays, in order to increase the efficiency and validity of decisions taken by military com- mand and control bodies, there are military simulation complexes. They are a combination of hardware and software that ensure calculations and simulation of military operations. The analysis of the struc-ture and functionality of the software of modern modeling complexes has shown that their efficiency when used for their intended purpose is largely affected by the duration of input of initial data on po-tential adversary’s actions. However, in the general software architecture accepted for supply to the subdivisions of the control bodies, modeling complexes, a specific technological toolkit that allows minimizing the time spent on information input under the conditions of limited periods of software ap-plication has not been implemented. The paper discusses the issues of building software in military simulation complexes, which make it possible to reduce the time spent on entering initial data in the process of simulating combat operations in the aerospace sphere. The purpose of this paper is to assess the effect of replacing the actual values of the input parame-ters about the strike of a probable aerospace enemy with default values on the indicators of the combat operation simulation results. Scientific novelty is the development of a new method for constructing software for military simulation complexes. There are numerical examples of calculating default values provided. The preferred option for building software is proposed on the example of introducing tech-nological developments into the general software architecture of the modeling complex.

8. A mathematical model of vacuum freeze-dryer with uneven vapor distribution over the chamber volume [№3 за 2021 год]
Authors: Mokhova E.K., Gordienko M.G.
Visitors: 3814
A vacuum freeze-drying process is used to dehydrate thermolabile substances, and is widely used in biotechnology, pharmaceutical and food industries to obtain dry tissues, drugs and products without losing their structural integrity and biological activity. Nowadays, there is a need to study the influence of pressure gradients in the vacuum chamber on the drying rate of materials located at different dis-tances from the condenser. Uneven removal of solvent vapor from the surface of the material during the drying process can lead to significant differences in drying rates in different parts of the chamber. Within the framework of this work, the authors jointly used two models: a mathematical model for calculating the kinetics of the vacuum freeze-drying process (native software); Computational Fluid Dynamics (CFD) model for predicting water vapor pressure above a material surface (Ansys Fluent 17.0 software package). The data between the models was transferred by transferring the values of the mass flow of evaporated moisture calculated by the drying kinetics model, through UDF files at speci-fied time intervals. UDF data was used as boundary conditions. The obtained distributions of the water vapor partial pressure were transferred to the kinetic model as boundary conditions for the next cycle of iterations. The joint solution of two mathematical models made it possible to obtain the kinetic char-acteristics of the drying process for 2 mass. % aqueous sodium alginate taking into account the uneven distribution of water vapor over the vacuum chamber volume. The paper shows that for the ScanVac Coolsafe 100-9 dryer model at the considered mass flows, there is a rapid equalization of the pressure profile along the height of the working chamber, which ensures uniform conditions for material drying. Based on the results of a series of computational experiments, the authors give recommendations on the thermal regime of vacuum freeze-drying of medical materials based on alginate hydrogel.

9. The models of analyzing and forecasting load of radar station computing and power resources [№3 за 2021 год]
Authors: A.A. Nepryaev , Shpigar A.N.
Visitors: 3653
The paper proposes a method for solving the problem of distribution of computing and power resources of a multifunctional multichannel radar station with an active phased antenna array. This method is based on using a cognitive radar resource management system that plans its real-time actions based on analyzing an external situation and an internal state. The main component of the cognitive control system is a radar scheduler based on Orman's algorithm, which takes into account available time, power and computing resources and provides an optimal distribution of the radar final resources. To solve the problem of analyzing and forecasting the distribution of power resources, there is a transceiver module thermal model; for computing resources, there is a model of the primary radar plot extraction. The transceiver module thermal model is designed to simulate thermal processes occurring during the sounding signal emission and in pauses. The processing pipeline model calculates the time required for the automated system to process the received radar information. It allows forecasting the load level of computing resources when planning the radar operation modes. The purpose of the paper is to demonstrate the results of modeling a radar scheduler showing how it is possible to analyze and forecast the available time and power resources using the developed models, as well as how to redistribute them between radar tasks. It is shown how the radar scheduler generates a time diagram and places items of temporary task bundles on the timing pipeline taking into account computing and energy resources.

10. The program for forming a stack of artificial intelligence methods to solve applied problems [№3 за 2021 год]
Authors: A.Yu. Puchkov , E.I. Lobaneva , M.A. Vasilkova
Visitors: 3770
The paper proposes an algorithm for automated selection of a stack of artificial intelligence methods for data processing based on taking into account their characteristics, such as volume, presentation format, as well as the specifics of the problem solved based on these data. The purpose of the study is to develop a system of assessments and criteria to select a stack (a list of methods reflecting different levels of their suitability for solving an applied problem) of artificial in-telligence methods, which makes it possible to effectively implement the required target parameters of data processing, as well as creating an algorithm to form such stack. The task of the study was to analyze the problem of choosing a paradigm of artificial intelligence methods, to determine an assessment system that most fully reflects the features of the subject area for which the paradigm is selected, to develop a program that forms a stack of data processing methods. Considering the variety of artificial intelligence methods, and with the aim of concretizing the research task, machine learning methods were considered. To provide the possibility of applying simpler analy-sis methods to the obtained data, a choice of statistical methods also related to machine learning tech-nology was provided. The developed algorithm for choosing a stack of artificial intelligence methods contains a multi-stage procedure. It includes the following: assessment of the parameter importance in terms of their im-pact on the target parameter; the use of a fuzzy inference system that, ranks the proposed set of pro-cessing methods based on the specified expert assessments of data characteristics; selection of web-sites and search in them for subject area keywords reflecting the task for the solution of which the pro-cessed data is used. The paper presents the program work results written in the MatLAB language and implementing the proposed algorithm, which demonstrate the correct choice of artificial intelligence methods based on the given characteristics of the input information.

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