No. 5 (2021)

Wireless sensor networks (WSNs) are being actively implemented in various systems for remote
observation and monitoring of distributed objects. WSNs have a number of undoubted advantages:
flexibility, efficiency, relative cheapness, and the possibility of rapid deployment. However,
the exchange of information and data is carried out in the WSN using wireless communication
channels, which are subject to inevitable interference and noise, which leads to transmission errors and even to the loss of transmitted data packets. Another challenge, not fully resolved, is the
uneven distribution of consumed energy within the WSN in the face of stringent requirements for
energy sources. Currently, there are two most widely used retransmission schemes in the loss of
transmitted data, namely, hop-by-hop and end-to-end. Most of the well-known studies devoted to
the issues of reliable data transmission in WSN using these schemes have been carried out experimentally.
In addition, there are still no analytical methods for evaluating various reliable
transport solutions, which complicates the analysis of the proposed WSN. Therefore, the aim of the
proposed work is the development of analytical methods and algorithms for studying the operating
characteristics of the signal relaying circuits in the WSN. Analytical methods are proposed for
evaluating retransmission schemes in the WSN, based on a relatively new theoretical basis - the
network calculus for packet-switched networks, which is a tool for determining the size of the network.
First, traffic, service and energy cost models are introduced. Based on these models and
network calculations, the maximum packet transmission delay and energy efficiency of the two
main types of retransmission schemes: hop-by-hop and end-to-end retransmission, are analytically
estimated. According to the results of the experiment, the maximum latency and the maximum
power consumption of these two schemes are compared in several scenarios. In addition, the analytically
calculated maximum delay is compared with the simulation results. With the proposed
method, a suitable retransmission scheme can be selected based on the various requirements and
constraints to be set.

The article considers some practical issues of solving the problems of improving the technology
of aerial-chemical works using methods of computer modeling of its processes, in particular, on
non-traditional modes of aviation spraying. These modes are typical for the treatment of areas with
obstacles at the borders, when the introduction of working fluids is carried out when the aircraft
descends in the approach to the production passage over the area at the required flight altitude and
climb after its end. The carried out computational and theoretical studies on the example of the An-2
biplane aircraft using the previously developed and tested multifactor software tools for modeling the
processes of forming a vortex trace of an aircraft and depositing in it a spectrum of drops of working
fluids characteristic of aviation spraying have shown that the use of unconventional technological
treatment modes can significantly increase the productivity, safety and integral efficiency of aerialchemical
works and measures for chemicalization of agricultural production in general. It is shown
that to increase the efficiency of aviation spraying of areas limited by obstacles, it is technically possible
and economically feasible to use a work scheme that provides for the beginning and end of processing
of such areas at the stage of descent and climb at distances from obstacles corresponding to
1-2 seconds of the aircraft flight (for An-2 aircraft at distances of 50–150 m at a flight altitude of up
to 20 m). Such a scheme provides an increase in the productivity of aviation spraying up to 10–15 %,
a reduction in the prime cost of treatments by 3–5 % and an increase in economic efficiency by
2–3 % with an increase in their total effect by 6–8 %.

In systems for automatic measurement of the duration of video pulses, various devices for amplifying
and shaping pulses of a normalized level are used, the duration of which is equal to the duration
of the input signals. A rough measurement of the duration of video pulses can be made with onethreshold
meters. More accurate are multi-threshold and floating-threshold meters. Pulse duration
meters have found wide application in electronic warfare equipment, in measuring technology. The
variation in the shape of electrical signals does not allow the use of a single measurement method,
which is the best for all shapes, therefore, the search for technical solutions that satisfy the conflicting
requirements continues: a wide range of durations and duty cycles. The aim of this work is to
carry out a mathematical analysis of the random error in measuring the pulse duration with oscillations
at the top by multi-threshold duration meters. In the course of the work, the results of a numerical
experiment were obtained to measure the duration of a pulse with oscillations at the top using
multi-threshold duration meters. And also a comparison was made of four multi-threshold duration
meters for the investigated pulse shape. The calculation results are presented for a signal dynamic
range of 60 dB and an amplitude quantization step of 3dB and 12 dB.

The ability of a multi-unit in-pipe robot to drive through curved sections of a pipeline is an important
indicator of its capability to move through the pipeline. At the design stage, this indicator
cannot be verified without mathematical simulation of the robot spatial movement and interaction of
its running gear with the pipeline. The objective of this work is to create a dynamical model for evaluation
of the two-link in-pipe wheeled robot capability to drive through a pipeline. The model was
developed in the Universal Mechanism multibody system simulation program with the use of its
standard elements of the mechanical system modeling and a special-purpose wheel – pipeline contact
model developed by the authors. The wheel – pipeline contact model was created in MATLAB and
compiled as a DLL. The developed multibody model was verified by the robot behavior during its
motion through a bent section of the pipeline and by the time histories of the indicators of its capability
to drive through the pipeline. Two directions of the pipeline bend were studied. The minimum
distance from the extruding electric motors of the robot actuators to the internal surface of the pipeline
has been offered as an indicator of the robot ability to move through the pipeline. The analysis of
the simulation results has proved the adequacy of the model behavior and showed that the developed
multibody model can be used for the evaluation of the robot capability to move through the pipeline
at the early design stages before fabrication of its prototype.

The paper proposes a semi-Markov model of telecommunication network. The variant of dynamic
traffic control of queuing system as a special case of telecommunication network is considered.
The main purpose of control is to minimize the average cost per unit of time to service the
incoming flow of information (packets). This takes into account the different bandwidth of the
channels, the processing speed of information in the channel and the information capacity of the
buffers. The approach to the organization of dynamic control taking into account noise immunity
(information reliability) and information security is discussed. The problem of dynamic control of
a telecommunication network is considered on the example of a simple single-channel structure of
the “point-to-point” type, which is modeled as a linear unidirectional Markov chain. The parameters
of the service tariff, the cost of the fine for refusal of service were introduced. The analysis
allows us to make the following remarks that the distribution of the input information flow of
packets is Poisson, the law of distribution of the length of packets and the speed of their arrival is
exponential, which together characterizes the Markov process. However, there are concurrent
service delays relative to the timing of service requests, including buffer overflow delays. The proposed
semi-Markov model of a telecommunications network can be used for more complex network
structures. In particular, for a telecommunication network, consisting not only of one singlechannel
information transmission system (single-channel queuing system), but representing a set
of several systems, that is, for multichannel telecommunication networks.

Currently, the most widespread wireless access technology, which is widely used to transmit
a large amount of traffic of various types, is the IEEE 802.11 wireless LAN standard. MESH networks
have become one of the most promising areas of technology development. MESH networks
provide the most interesting solutions integrating various wireless access technologies. The possibility
of organizing local (LAN) and metropolitan (MAN) networks using MESH topology, easily
integrating into wide area networks (WAN), is a positive factor for use on a ship. In maritime
practice, networks based on digitalization and automation are increasingly used. This article discusses
modeling the interaction of devices in a MESH network based on the ZigBee specification,
the principle of operation of the data link layer, which is used in this network, as well as a variant of the method for preventing increased consumption of energy used by the network. One of the
advantages of the ZigBee network is the ability to track network participants and the topology
itself in the mode of their frequent connections, disconnections and reconnections. In this case, it
is necessary to analyze the network speed, reliability, bandwidth. For this purpose, we estimated
the average waiting time for connecting a node, the probability of a successful connection of a
node to the network, the probability of finding a channel busy during the first and second probing
of the carrier, and a test of the throughput of the network under consideration. The obtained results
of the analysis indicate the operability of the network in various situations: both under normal
conditions and in a difficult jamming environment.

Currently, piezoresistive pressure sensors (PDS) find expanded applications in various microelectronic
devices used in aviation technology. The behavior of the electrical signal of such
PDS mainly depends on the ambient temperature. It is known that the temperature drift of the PDS
output signal is influenced by various factors: the temperature effect, the dependence of the resistance
of the sensitive element on the concentration of impurities, the dependence of the Young's
modulus of the sensor membrane and substrate materials on temperature, etc. It was found that the
previously developed analytical calibration model of the sensor output signal, which takes into
account the models describing individual temperature effects, does not allow the pressure to be
measured with the required accuracy in the temperature range characteristic of aviation equipment
from –60 C to 140 C. Therefore, conventional polynomial mathematical models are used to
describe the dependence of the PDS output signal on the measured pressure and temperature.
The work uses a traditional approach, when the dependence of the output voltage on pressure is represented using a polynomial of relatively low order, and the dependences of the coefficients of
this polynomial on temperature are also specified by the corresponding polynomials. Unfortunately,
the temperature dependences of the coefficients are adequately described only by high-order
polynomials (at least 7), which complicates the model identification procedure and leads to computation
errors. Therefore, the authors proposed to look for the dependence of the coefficients on
temperature in the form of cubic splines. The paper describes in detail the identification technique
of the polynomial model under consideration and obtains expressions for correcting the PDS readings
when measuring pressure in wide temperature ranges. In order to experimentally confirm the
efficiency of the proposed method, an intelligent industrial automated system for the calibration of
traffic rules, described in the work, was used. It is shown how it can be used to take experimental
data to calibrate the sensor readings over a wide temperature range, and the procedure for identifying
the mathematical model of the pressure sensor required to minimize the cost of its certification
is described. The results of experimental studies of specific pressure sensors used in aviation
technology are presented.

The necessity of regulating the temperature of the coolant in hydraulic presses, providing
hot gluing of plywood, regulating the pressure in the press channels and maintaining technological
parameters at a given level, is considered. A column hydraulic press P-714-B for hot gluing of
plywood, installed at the Ust-Izhora plywood mill, is considered as a control object. The article
provides a description of the column hydraulic press. To monitor the parameters of the presented
installation of plywood production, it is proposed to consider the heating press plates and plywood
packages as an object with distributed parameters. To develop a mathematical model of the control
object, a functional diagram of this device with the main equipment and technological flows of
the coolant was considered. A technique has been developed for modeling objects of this class as
objects with distributed parameters. Consideration of the processes occurring in the channels of
the heating plates made it possible to formulate differential equations of motion that describe the
flow of the working medium in the system of channels. The developed method of mathematical
modeling of heat propagation in the heating plates of the press and plywood packages made it
possible to draw up a mathematical model for the object under consideration. This mathematical
model turned out to be quite complex, and it is not possible to solve the resulting system of partial
differential equations analytically (to isolate the transfer function). For a numerical analysis of the
considered control object, a discrete model of equations and a computational algorithm were
compiled. In the process of compiling discrete models, the problems of “joining” the boundary
conditions were solved, the stability of the computational scheme was ensured, and the steps of
discretization with respect to spatial variables were selected. Software was specially developed for
computer modeling. With its help, the temperature values at the control points were calculated.
The presented mathematical model made it possible to carry out a numerical experiment, as a
result of which the frequency characteristics of the object under study were obtained. These characteristics
were used in the synthesis of a distributed high-precision controller.

To predict emergencies and irreversible consequences of human activities, scientists use
mathematical modeling. When an emergency occurs, it is very important to minimize the decisionmaking
time. The development of the project solution can be based on the forecast of changes in
the modeled process. In the numerical solution of problems of hydrophysics and biological kinetics,
it becomes necessary to develop effective methods for solving systemic equations of large dimension
with a non-self-adjoint operator. The large volume of processed information and the
complexity of computations necessitate the use of computational clusters, which include video
adapters to increase the performance of the computing system and the speed of information processing.
The aim of the research is to develop a solution for a module that implements the algorithm
of the system of linear algebraic equations (SLAE) by the modified alternative triangular
iterative method (MATM) (self-adjoint and non-self-adjoint case) using NVIDIA CUDA technology.
A method for decomposition of the computational domain in a three-dimensional case is described.
A graph model of a parallel pipeline computational process is proposed, focused on the
GPU (Graphics Processing Unit). To determine the two-dimensional configuration of flows in the
computational unit, when performing one step of one step, the MATM is minimal. The studies have
shown that the choice of the method of decomposition of the computational domain in the form of
parallelepipeds must be performed taking into account the architecture of the video adapter. The
developed algorithm and software module make it possible to more effectively use the computational
resources of the GPU used to solve computationally laborious problems of hydrophysics.

The paper considers the problem of workload distribution in a group of unmanned aerial vehicles
(UAVs) when monitoring a certain area in a changing environment, which has a direct impact on the
onboard energy resources consumption. The stage of a monitoring problem-solving, which includes the
distribution of UAVs over scanning bands, is described here. When this stage is carried, there is no
opportunity to take into account the factors of environmental impact. But these factors are crucial
due to the limited onboard energy resources. In this regard, a situation is very likely when the UAV is
not able to complete the sub-task assigned to it, which jeopardizes the completion of the entire mission
of the group. To avoid this situation, it is proposed to use the technique of a decision-making on
the need to relocate the workload in a group of mobile robots (MR). The decision-making is based on
the ontological analysis procedure, which allows limiting the number of choices for workload relocation.
The ontology model of the workload distribution in a group of UAVs was developed. This model
takes into account the possibility of additional performance involvement either by means of the resources
of neighboring UAVs, or by means of devices of the "foggy" layer. Examples of production
rules are given, on the basis of which a decision is made on the need to relocate the workload. A
comparative estimation of the resources volume involved in the implementation of two methods of
workload relocation problem solving, depending on the frequency of changes in environmental conditions,
is carried out. The results of computational experiments have shown that the method based on
ontological analysis is more efficient in comparison with the method based on LDG (Local Device
Group) in terms of the amount of resources involved. This makes it possible to increase the time of joint
mission implementation by the UAV group.

The aim of the work is the development and implementation of the architecture of a cloud
storage system, systematization and processing of survey results (for example, EEG) and an algorithm
for ensuring the protection of confidential data based on a completely homomorphic cryptosystem.
The object of the research is the technologies of storage, transmission, processing and
protection of confidential information in distributed medical information systems. The architecture
of a cloud platform for distributed storage, processing, systematization and protection of confidential
data (results of medical examinations) has been developed, which makes it possible to interact
with various medical information systems and diagnostic hardware in order to generate big data.
An algorithm has been developed to ensure the safety of medical data stored in a cloud platform in electronic form, recorded during patient examinations in order to calculate the average value for
each of the brain activity rhythms (based on the results of a series of examinations over a long
period of time) using a fully homomorphic encryption algorithm. Based on the test results (analysis
of the execution time of such operations as: encryption, decryption, addition, multiplication,
signal-to-noise ratio of ciphertext to plaintext), the optimal algorithm. According to the results of
the work, it is shown that the fully homomorphic encryption scheme CKKS is the most effective,
especially in the context of the criticality of the requirements for a high level of security of confidential
data, which determines the choice of this scheme for the implementation of the algorithm
proposed in this work.

Recently, there has been a rapid increase in interest in quantum computers. Their work is
based on the use of quantum-mechanical phenomena such as superposition and entanglement for
computing to transform input data into outputs that can actually provide effective performance
3–4 orders of magnitude higher than any modern computing devices, which will allow solving the
above and other tasks in real and accelerated time scale. This work is a study of the influence of
the environment on a quantum system of qubits and the results of its implementation. A probabilistic
deep neural network decoder for stabilizer codes has been developed. The issues of error correction
for a three-bit code without state decoding are analyzed and considered. The relevance of
these studies lies in mathematical and software modeling and implementation of correction codes
for correcting several types of quantum errors in the development and implementation of quantum
algorithms for solving classes of problems of a classical nature. The scientific novelty of this direction
is expressed in the elimination of one of the disadvantages of the quantum computational
process. The scientific novelty of this area is primarily expressed in the constant updating and
supplementation of the field of quantum research in a number of areas.

Recognition of certain patterns in video images captured by a camera is carried out using
training methods based on convolutional neural networks. The larger the number of images with
multiple features and the more diverse the training sample of video images, the better the convolutional
neural networks extract features from the sequence of video images that were not included in
the training sample. This is a consequence of increasing the accuracy of detecting visual images on
video images containing features of target images. However, there are limitations in improving the
detection performance when the size of the image to be detected is much smaller than the background
area, or when the image is described with little information. To solve problems of this kind, the authors
of the article have developed an algorithm for the spatio-temporal integration of information
about the movement of dynamic images. The algorithm processes a fixed number of video images at
certain points in time and extracts new independent signs of motion of dynamic images based on
space-time processing of video images. Further, it combines new local motion features with the original
video image features. This allows you to add a motion feature of dynamic images while preserving
the original image features that describe static images. Areas of the video image that characterize
the motion feature are displayed in a «color» cluster. The use of pre-processing is aimed at improving the accuracy of pattern detection, provided there are dynamic visual images on a static background.
If the camera is in scan mode, a static background can be provided with a video stabilizer.
Experimentally, estimates of integral criteria for the accuracy of detection neural network algorithms
have been obtained, showing an increase in the accuracy of detecting visual images using
the algorithm for spatial-temporal integration of motion information.

At present, various computer-aided (CAD) systems are used for solving tasks on reconfigurable
computing systems (RCS). In most cases, they consist of two main parts: a compiler (translator),
which translates the source code of a program into a graph-like information and computing
structure, and a synthesizer, which maps it on an FPGA architecture. As a rule, existing synthesizers process computing structures without any complex optimization. Therefore, the solution, generated
by the synthesizer, may contain inefficient fragments, which decrease a task solution speed.
The most common examples of inefficient computing structures are fragments which implement
recursive expressions. The paper proposes transformation methods for recursive expressions
(fragments with feedbacks), which allow automatically reduce the data supply interval when solving
tasks on reconfigurable computing systems. The methods are based on information-equivalent
transformations of the computing structure of the original task. For each transformation defined a
set of rules that must be satisfied by the vertices of the computing structure. Applying rules allows
to perform equivalent transformations not only on simple data structures such as numbers, but
also on more complex structures (matrices, vectors, tensors, etc.). On the base of the simulation
results, the developed transformation methods of computing structures with feedbacks allow to
reduce the task solving time about 2–5 times by reducing the data supply interval. The proposed
methods are implemented in a prototype of optimizing synthesizer.

The article discusses the developed authorized methodology based on the Ideal Point Method
using the Pareto set, which makes it possible to look from modern technological positions at the
features of information interaction for evaluating activities and regulating inter-agent interactions,
which was the basis for the discipline updates of the Russian Technological University proposed
with the participation of the authors ( MIREA), Institute of Information Technologies, Department
of Instrumental and Applied Software "Information Management of Systems" of the
fourth year of the bachelor's degree program 09.03.04 "Software Engineering" (specializing in
"Software Development and Design of Information Systems"). The main advantages of the Ideal
Point Method using the Pareto set are described. The mathematical description of the Pareto set
and the Ideal Point Method is presented. The use of the modernized method makes it possible to
improve the indicators of emergence in the process of improving educational programs, connecting
and reconstructing their modules and inter-agent interactions between them. An example of
the implementation of the modified method in the information system is shown, from the point of
view of standardization and harmonization of educational content. This article includes an introduction,
a formal formulation of the problem, designed to solve an urgent problem considered in
the dissertations of the authors, a review of existing approaches in this method, a description of
the proposed multi-agent solution to the problem using a mathematical model, an implementation
algorithm, a description of the application of the proposed approach in relation to the task scheduling
process, and a conclusion ... The main advantages of this technique include the choice of
criteria that surpass others in terms of a set of features; this method assumes the creation of an
"ideal object", that is, a certain solution option that can be taken as the best possible solution. It is
assumed that the procedure for selecting a superior object consists of several steps, the formation
of an "ideal object", determination for each object of the multi-criteria distance to the "ideal object",
analysis of the set of objects for proximity to the "ideal object", exclusion of objects from the
initial set, which are deliberately recognized unsuccessful, as well as obtaining a reduced set of
admissible objects; assessment of the reduced set of feasible objects for emergence indicators of
the solution found.

In this work, to solve the VLSI planning problem, a search algorithm has been developed
based on a modified ant colony method. The task of forming a VLSI plan is reduced to the task of
forming the corresponding Polish expression. The developed method for the synthesis of the Polish
expression includes the construction of a tree of cuts, the choice of the types of cuts (H or V), identification
and orientation of modules. The evolving population is split into pairs of agents. Each
member of the population is a pair of agents working together. In this case, the constructive algorithms
A1 and A2 used by the agents of the pair are different. The problem solved by Algorithm A1
is formulated as the problem of finding a one-to-one mapping Fk=M*→P of the set of modules M
with selected orientations, |M*|=|M| to the set P of positions of the template Sh. In fact, the solution
consists in choosing on the graph G1 a subset of edges E*1E1 included in the corresponding
mapping Fk. In Algorithm A2, the graph G2=(X, E2) is developed as a model of the search space
for solutions for choosing the type, sequence and location of cuts in the pattern Sh.
X={(x1i,x2i)|i=1,2,…,n} the set of vertices of the graph G2, corresponds to the set P of potential
positions of the template Sh for the possible placement of the names of the cut symbols in them.
Each potential position piP of the template Sh is modeled by two alternative vertices (x1i,x2i).
The choice of the vertex x1i when placing the cuts indicates that a cut of type V is placed in position
pi, the choice of vertex x2i indicates that a cut of type H is placed in position pi. Each iteration
l of the general algorithm includes an initial and three main stages. The initial stage is as follows.
Co-evolutionary memory matrices are nullified CEM*1 and CEM*2 are reset to zero. At the first
stage, each pair of agents dk=(a1k,a2k): – with constructive algorithms A1 and A2 he synthesizes
his solution Wk=(E1k
*,Sk); – the Polish expression Shk is formed, corresponding to the solution Wk;
– on the basis of Shk, a tree of sections Tk is formed; – on the basis of Tk, the plan Rk is formed and
the estimate of the solution Fk is calculated; – agents deposit (add) the pheromone to the cells of
the collective evolutionary memory (CEM) matrices CEM*1 and CEM*2 corresponding to the
solution edges Wk=(E1k
*,Sk) in the solution search graphs G1 and G2 in an amount proportional
to the solution estimate Fk. At the second stage, the pheromone accumulated in CEM*1 and
CEM*2 by agents of the population at iteration l is added to CEM 1 and CEM2. At the third stage,the pheromone is evaporated on the edges of the graphs G1 and G2. Tests have confirmed the
effectiveness of the proposed method. The time complexity of the algorithm, obtained experimentally,
coincides with theoretical studies and it is O(n2) for the considered test problems.