bluuebunny/crossref_metadata_2025 huggingface dataset:
The financial impacts of board mechanisms on performance: The case of listed Moroccan banks
Authors:   Laboratory of Finance, Audit and Management Research, LAREFAG, ENCG, Abdelmalek Essaadi University, Tetouan, Morocco, El Idrissi Issam , Alami Youssef ,   Laboratory of Finance, Audit and Management Research, LAREFAG, ENCG, Abdelmalek Essaadi University, Tetouan, Morocco
Published: October 2021

Abstract Purpose: The present study examines the impact of corporate governance mechanisms on listed Moroccan banks' financial performance. Research methodology: This study investigates the relationship between listed banks' governance mechanisms and financial performance in the CSE for six years between 2014-2019. This study employs three performance measures, return on assets, return on equity, and Tobin's Q, to determine bank performance. This research uses the GMM EGLS approach to analyze data. In the first phase of this empirical research, we did use OLS, Fixed Effects, and Radom Effects regressions to show their inefficiency. Results: Our results portray that most board mechanisms have a negative impact on financial performance. In comparison, the audit committee and nomination & remuneration committee have a positive effect on financial performance. Limitations: Many qualitative and quantitative factors could influence financial performance and not only the used variables in this paper. Contribution: This research shows that the dynamic connection between corporate governance and financial performance is robust in the Moroccan banking context. Also, our study has important implications for establishing good corporate governance practices in emerging economies.
Reaction Wheels Fault Isolation Onboard 3-Axis Controlled Satel-lite using Enhanced Random Forest with Multidomain Features
Authors: Rahimi Afshin , Folami Mofiyinoluwa O.
Published: October 2021

As the number of satellite launches increases each year, it is only natural that an interest in the safety and monitoring of these systems would increase as well. However, as a system becomes more complex, generating a high-fidelity model that accurately describes the system becomes complicated. Therefore, imploring a data-driven method can provide to be more beneficial for such applications. This research proposes a novel approach for data-driven machine learning techniques on the detection and isolation of nonlinear systems, with a case-study for an in-orbit closed loop-controlled satellite with reaction wheels as actuators. High-fidelity models of the 3-axis controlled satellite are employed to generate data for both nominal and faulty conditions of the reaction wheels. The generated simulation data is used as input for the isolation method, after which the data is pre-processed through feature extraction from a temporal, statistical, and spectral domain. The pre-processed features are then fed into various machine learning classifiers. Isolation results are validated with cross-validation, and model parameters are tuned using hyperparameter optimization. To validate the robustness of the proposed method, it is tested on three characterized datasets and three reaction wheel configurations, including standard four-wheel, three-orthogonal, and pyramid. The results prove superior performance isolation accuracy for the system under study compared to previous studies using alternative methods (Rahimi & Saadat, 2019, 2020).
SOCIO-ECONOMIC EMPOWERMENT OF WOMEN THROUGH MICRO CREDIT: AN EMPIRICAL STUDY
Authors: Indumathi T. , Savaraiah G.
Published: October 2021

The World Bank's Andhra Pradesh Rural Poverty Reduction Project supports the self helf groups of the women
members. It promotes women's social, economic, legal and political empowerment to reduce poverty among the poor
and the poorest of the poor. The important object of this article is to examine the impact of micronance on the socio economic empowerment of
the rural women supported by the national reputed NGO- Rashtriya Seva Samithi (RASS). 184 women members of the SHGs promoted by
Rasthriya Seva Samathi (RASS) an NGO which located in Tirupati town. 184 samples are selected randomly from 15 SHGs scattered throughout
the Tirupati rural mandal (Taluk) from the area of the study have been considered to conduct the present research study. The study reveals that
87.71 percent of the sample women were below the poverty line before joining the SHGs. As a result of SHG, about 40 percent of the sample
women crossed the poverty line. The highest intensive value indicates that more women have participated in social agitations for the welfare of
the children and the society. The second highest intensity reveals that considerable numbers of women of SHGs have participated in the
government sponsored schemes. The 1st point secured 3rd rank with total intensity value of 605 which status that the micro credit has resulted in
increased social status and empowerment.
A STUDY ON FINANCIAL ANALYSIS AND PERFORMANCE OF HDFC BANK
Authors: Karthika. K.
Published: October 2021

This study has been carried out to evaluate the nancial performance of HDFC bank. HDFC was amongst the rst to
receive an 'in principle' approval from the Reserve Bank of India (RBI) to set up a bank in the private sector. HDFC Bank is
the second largest Private sector Bank in India and one of the top 5 banks in the country. The bank has a network of 5000+branches and
16000+ATMs in 2902 cities/towns. HDFC Bank provides a number of products and services including wholesale banking and retail banking,
treasury, auto loans, two wheeler loans, personal loans against property, consumer durable loans, life style loan, credit cards and the various digital
products. The nancial performance of above mentioned bank has been evaluated for the past ve years i.e. 2017, 2018, 2019, 2020, 2021. The
data analyzed by ratio analysis such as current ratio, liquid ratio, xed assets ratio, debt-equity ratio and net prot ratio and give interpretation to
each ratio. To conclude this nancial soundness of the bank is satisfactory during the study period.
THE IMPACT OF COVID19 IN TOURISM SECTOR
Authors: P J Vindhya , Varma Ranjini R.
Published: October 2021

The tourism industry generally incorporates many industries including lodging, transport, travel companies etc. globally,
travel and tourism directly contributed approximately. The tourism sector has been considered as a good growth of the
economy. Global tourism is an invisible export that creates a ow of foreign currency into the economy. Unexpected conditions of global
recession emerged, travel restrictions, lockdowns and social- distancing. Thus, it is understood that the impact of covid-19 pandemic has effect the
tourism sector. This study is mainly conducted in order to nd out how deep the impact of covid-19 pandemic has effect the tourism industry in
general and in India as well. Hence, there is no doubt that the global economy need to come out of this pandemic as soon as possible. Experts has
emphasized on the need and potential to tap domestic tourism and thereby make use of its forward as well as backward linkages to stimulate the
economic indicators. The travel and tourism industry sector requires constructing the approach by introducing the essential measures like, social
distancing, wearing mask when stepping out, changing people's social behavior. The capitalizing on safety and hygiene would reassure customers
in availing their services.
A Theory for Electromagnetic Radiation and Coupling
Authors: xiao gaobiao
Published: October 2021

A
theory for analyzing the radiative and reactive electromagnetic energies of a radiator in vacuum is presented. In vacuum, the radiative electromagnetic energies will depart from their sources and travel to
infinity, generating a power flux in the space. However, the reactive
electromagnetic energies are bounded to their sources. They appear and
disappear almost in the same time with their sources, and their fluctuation
also causes a power flux in the space. In the proposed theory, the reactive electromagnetic energies of a radiator are
defined by postulating that they have properties similar to the self-energies
in the charged particle theory. More importantly, in addition to a main term of
source-potential products, the reactive energies contain a special energy term which will last to exist a short time after the sources disappear. This
oscillating energy is related to the electric displacement and the vector
potential, and seems to be responsible for energy exchanging between the reactive
energy and the radiative energy in the radiation process, performing like the Schott
energy term. As the Poynting vector describes the total power flux density
related to the total electromagnetic energy, it should include the contributions of the propagation of the radiative energies and the fluctuation of the
reactive energies. The mutual electromagnetic couplings between two radiators
are also defined in a similar way in which the vector potential plays a central
role. The reactive electromagnetic energies can be evaluated with explicit expressions in time domain and frequency domain. The theory is verified with
the Hertzian dipole and numerical examples.
A novel framework based on deep learning and ANOVA feature selection method for diagnosis of COVID-19 cases from chest X-ray Images
Authors: Nasiri Hamid , Alavi Seyyed Ali
Published: October 2021

The new coronavirus (known as COVID-19) was first identified in Wuhan and quickly spread worldwide, wreaking havoc on the economy and people's everyday lives. Fever, cough, sore throat, headache, exhaustion, muscular aches, and difficulty breathing are all typical symptoms of COVID-19. A reliable detection technique is needed to identify affected individuals and care for them in the early stages of COVID-19 and reduce the virus's transmission. The most accessible method for COVID-19 identification is RT-PCR; however, due to its time commitment and false-negative results, alternative options must be sought. Indeed, compared to RT-PCR, chest CT scans and chest X-ray images provide superior results. Because of the scarcity and high cost of CT scan equipment, X-ray images are preferable for screening. In this paper, a pre-trained network, DenseNet169, was employed to extract features from X-ray images. Features were chosen by a feature selection method (ANOVA) to reduce computations and time complexity while overcoming the curse of dimensionality to improve predictive accuracy. Finally, selected features were classified by XGBoost. The ChestX-ray8 dataset, which was employed to train and evaluate the proposed method. This method reached 98.72% accuracy for two-class classification (COVID-19, healthy) and 92% accuracy for three-class classification (COVID-19, healthy, pneumonia).
A novel instrumented outsole for real-time foot kinematics measurement: validation across different speeds and simulated foot landing in Cerebral Palsy gait
Authors: Bajpai Rishabh , Tiwari Ashutosh , Jain Anant , Joshi Deepak
Published: October 2021

Neuromuscular disorders in Cerebral Palsy (CP) patients lead to foot deformities and affect foot biomechanics leading to compromised gait. Thus, measurement of the foot kinematic measurement is of particular interest to understand and characterize the walking pattern among CP patients. The objective of the present work is to develop a wearable instrument to measure foot kinematics such as foot-to-ground angle in three-dimensional planes and to measure the foot clearance i.e., toe and heel clearances. A template-based outsole was developed that incorporated an optical distance sensor located anatomically on the outsole and the magnetometer to measure the foot kinematics. The developed system was validated against the reference marker-based motion capture system (from Noraxon). The data from eight able-bodied participants were acquired simultaneously from both the systems (developed and the reference system) at three different walking speeds. A CoP based feedback was presented to the participants to shift the sagittal CoP anteriorly, posteriorly and normal to simulate the walking pattern of CP patients with three different foot landing strategies. Pearson's correlation coefficient of more than or equal to 0.62, root mean square error of less than or equal to 7.81 degrees and limit of agreement of more than or equal to 95% is found. Furthermore, a wireless wristband is developed and validated for real-time vibrotactile feedback. The measurement accuracy reported with outsole while participants simulated CP gait shows the potential of present work in real-time foot kinematics detection in CP patients. The instrumentation is wearable, low-cost, easy to use and implement.
An Efficient BPSK Modulation and Demodulation Scheme with the Complete Removal of Fading
Authors: Nguyen Trang Tien , Ta Hien , Oh Hoon
Published: October 2021

A novel non-coherent BPSK modulation and demodulation scheme is
proposed to remove both slow and fast fading completely. We formulate a
compound function that reflects the different characteristics of both slow and
fast fading and prove that the scheme can remove fading from the function completely.
The scheme
is reified by a simple architecture that can remove slow and fast phase shifts completely
from the received signals. It is shown by using analytical model and numerical
data that the proposed scheme outperforms other ones significantly under the presence of both slow and
fast fading. The analytical results also show that the proposed scheme can work
well even with a small sampling rate, resulting in a wireless device with low
energy consumption.
Anomaly Detection based on Compressed Data: an Information Theoretic Characterization
Authors: Marchioni Alex , Enttsel Andriy , Mangia Mauro , Rovatti Riccardo , Setti Gianluca
Published: October 2021

We analyze the effect of lossy compression in the processing of sensor signals that must be used to detect anomalous events in the system under observation. The intuitive relationship between the quality loss at higher compression and the possibility of telling anomalous behaviours from normal ones is formalized in terms of information-theoretic quantities. Some analytic derivations are made within the Gaussian framework and possibly in the asymptotic regime for what concerns the stretch of signals considered.

Analytical conclusions are matched with the performance of practical detectors in a toy case allowing the assessment of different compression/detector configurations.
3D Face Alignment Method Applied to Face Recognition
Authors: Jabberi Marwa
Published: October 2021

Presentation of 3D Face Alignment method with application to Face Recognition
MAXIMUM POWER OF THE HF ANTENNA TUNER SWITCHED BY PIN DIODES AT LOAD MISMATCH
Authors:   Moscow Technical University of Communications and Informatics, Varlamov Oleg V.
Published: October 2021

PIN diodes, as inertial nonlinear elements, are widely used in transceiver equipment of various frequency ranges as limiters, attenuators and phase shifters. Also, with their help, it is possible to implement double-sided switching elements used, among other things, in switches and automatic antenna-matching devices of the HF range. Literary sources note that PIN diode switches in the HF range are capable of switching power up to 2 kW. In this case, only the task of switching the sub-octave bandpass filters of the transmitter is meant when operating at a perfectly matched load in a 50 Ohm path. The article discusses the features of the operation of PIN diodes in the HF range and determines the limiting values of the switched power depending on the parameters of the device and the load resistance. Examples of the circuit design of high-speed control circuits are given. The analysis of the maximum power of an automatic antenna-matching device of the HF range, carried out using the example of the most famous samples, with a load mismatch with PIN diodes, showed that in the case of a matched load, they can be used up to power levels practically equal to 2 kW. With a strong load mismatch, which is observed in most practical cases, especially when using communication facilities on mobile objects with electrically short antennas, the maximum power levels are reduced to 170 W when operating at frequencies above 3 MHz and to 100 W when operating at frequencies above 1 MHz.
EVALUATION OF QOS PARAMETERS FOR IPTV UNINTERRUPTED OPERATION
Authors:   Volgograd State Technical University, Antonenko Alexander S. , Zemtsov Andrey N. ,   Volgograd State Technical University
Published: October 2021

This article describes the IPTV system, as well as its implementation methods and related protocols. The concept of IPTV includes both real-time television and recording television, the so-called VoD. In real time, streaming data is sent using only the RTP protocol and in addition to it, the RTSP protocol is used for streaming VoD. In addition, methods for measuring QoS parameters are analyzed, considering practical applications for estimating IPTV traffic parameters. An important feature of providing quality IPTV services is a high level of quality of service. Also, in theory, an Internet connection model with insufficient network bandwidth is considered. The following characteristics are taken into account: bandwidth, one-way delay, inter-packet jitter, the number of lost packets, the number of duplicated packets, packets with errors, and damaged packets. A reordering issue is mentioned. In addition, two important QoS parameters for VoD are measured: START delay and PAUSE / RESUME delays. Service messaging is considered while providing IPTV service. The maximum, average, and minimum values for the network quality of service parameters are found.
METHOD OF STRUCTURAL SYNTHESIS OF RECEIVING AND TRANSMITTING RADIO DEVICES BLOCK SCHEMES
Authors:   MIREA – Russian Technological University, Vishnyakov Rustam R.
Published: October 2021

This paper is devoted to development of an algorithm for the synthesis of receiving and transmitting radio devices block schemes. Based on the presented algorithm, it is possible to develop a program that implements automated circuit synthesis. Such a program allows to a developer to obtain the most optimal scheme in the class of Pareto-optimal solutions. The algorithm is based on the method of exhaustive search of structural and elemental designs, and the decision-making method based on the criteria convolution method. The application of the exhaustive search of possible structural-element designs method allows creating a complete set of implementations and thus making choice decision of a scheme according to certain criteria among all possible constructions. This allows asserting the optimality of the obtained solutions, selected from a complete ensemble of possible designs. The use of the vector optimization method to select the optimal structural block scheme design of receiving and transmitting radio devices allows determining the most optimal construction according to the criterion for the highest value of the optimization function formed by the criteria convolution method. In the paper also considered a practical example of the synthesis of the input circuit of the receiving module RF part. As an example, the task of change the electronic components of the input part of the receiving module RF part with alternative microcircuits is given. To solve the described problem, a program was developed in the MATLAB. The results of the program are also given in the paper. The effectiveness of the developed algorithm and method for solving the task of synthesizing a block scheme from an elemental base represented by modern electronic components and circuit solutions is shown. Recommendations on further promising application of the proposed algorithm and method are presented.
COMPARATIVE ANALYSIS OF INFORMATIVE FEATURES QUANTITY AND COMPOSITION SELECTION METHODS FOR THE COMPUTER ATTACKS CLASSIFICATION USING THE UNSW-NB15 DATASET
Authors:   Moscow Technical University of Communication and Informatics, Sheluhin Oleg I. , Ivannikova Valentina P. ,   Moscow Technical University of Communication and Informatics
Published: October 2021

A comparative analysis of statistical and model-based methods for selecting the quantity and the composition of informative features was performed using the UNSW-NB15 database for machine learning models training for attack detection. Feature selection is one of the most important steps in data preparation for machine learning tasks. It allows to increase a quality of machine learning models: it reduces sizes of the fitted models, training time and probability of overfitting. The research was conducted using Python programming language libraries: scikit-learn, which includes various machine learning models and functions for data preparation and models estimation, and FeatureSelector, which contains functions for statistical data analysis. Numerical results of experimental research of application of both statistical methods of features selection and machine learning models-based methods are provided. As the result, the reduced set of features is obtained, which allows improving the quality of classification by removing noise features that have little effect on the final result and reducing the quantity of informative features of the data set from 41 to 17. It is shown that the most effective among the analyzed methods for feature selection is the statistical method SelectKBest with the function chi2, which allows to obtain a reduced set of features providing an accuracy of classification as high as 90% in comparation with 74% provided with the full set.
LOW LATENCY SEAMLESS LIVE TCP-STREAMING BY MEANS OF PROGRESSIVE DOWNLOAD METHOD
Authors:   Institute for High Energy Physics, National Research Center “Kurchatov Institute”, Lobov Igor V. , Gotman Vladislav G. ,   Institute for High Energy Physics, National Research Center “Kurchatov Institute”
Published: October 2021

The article discusses the client-server technology for organizing seamless live TCP-streaming with the use of progressive download method. Main factors which have a major impact on the overall playback latency have been identified. A study on the most important factor – the size of the client’s receiving buffer Lbuf – was carried out. It was found that the hypothetical display time of the last frame taken consists of two components: 1) the general instability, which has the character of a pronounced “band of instability”, and 2) episodic “drawdowns” associated with spontaneous media flow retentions in data transmission channel.The result of these drawdowns is an increase in Lbuf, resulting in increased playback delay. The article proposes a method to reduce the client’s receive buffer latency downto acceptable level (100-300 ms), allowing two-way communication between clients – an algorithm for smooth correction of client receiving buffer size. The article includes the results of the smooth correction algorithm in the implementation of TCP-Streaming by means of progressive downloading method. The implementation is a distributed software package consisting of one or more encoding processes, retransmitting process, client-side software. The media-flow Encoders converts data from the media-data sources (camera, computer screen, microphone) and transmits them to the clients via Retransmitter. The client-side software is a set of web pages (HTML + JS) where the receive buffer smooth correction algorithm is implemented. It was concluded that live TCP-streaming by means of progressive download method is quite suited to organize the communication with low latency between clients.
MATHEMATICAL MODEL OF INFORMATION SUPPORT FOR OPERATIONAL GROUPS OF THE FIRE AND RESCUE GARRISON
Authors:   Department of operational management of the EMERCOM of Russia, Rozhkova Natalia V. , Strakholes Andrei A. ,   Academy of the state fire service of the EMERCOM of Russia
Published: October 2021

Support for management decision-making in emergencies (firefighting), in uncertain conditions of its occurrence and uncertainty of its development is necessary for the organization of optimal distribution of the forces and resources of operational units involved in firefighting, and the knowledge of the Manager. The process of our research is limited only to the case of fire. Taking into account the fact that the data in the fire-extinguishing card does not always coincide with the state of the object where the fire occurred and the unpredictability of the direction of fire propagation, the decision-maker in this situation will organize work to obtain reliable information. These features allow us to consider the object where the fire occurred as a complex system. In this case, the main difficulty of information and analytical support for operational groups, as a management entity, is that at the first stage, the decision-maker in the operational group, without having complete reliable information, organizes its clarification. With the correct organization of their work, the task force ensures maximum efficiency of using the units of the Ministry of emergencies of Russia, when solving their combat tasks. At the same time, it can collect information about an emergency when it receives a notification of its occurrence, as well as on the way of the operational units to the specified area. The issues that determine the development of documents in different periods of the operational situation are considered, and the actions of the decision-maker in the operational group during fire extinguishing are highlighted separately. In this mathematical model, in which the transition of the system from the state of “fire occurrence” to the state of “fire extinguished” is modeled, the properties of a continuous Markov process are used. The solution of Kolmogorov’s system of differential equations determines the probability that characterizes the competence of the decision-maker in the task force.
MULTI-OBJECTIVE OPTIMIZATION OF VIRTUAL MACHINE PLACEMENT ON PHYSICAL SERVERS IN CLOUD DATA CENTERS
Authors:   MTUCI, Toutov Andrew V. , Toutova Natalia V. ,   MTUCI, Vorozhtsov Anatoly S. ,   MTUCI, Andreev Iliya A. ,   MTUCI
Published: October 2021

The problem of virtual machine placement on physical servers in cloud data centers is considered. The resource management system has a two-level architecture consisting of global and local controllers. Local controllers analyze the state of the physical servers on which they are located and determine possible underloading, overloading, and overheating states based on the forecast for the next observation window. If one of the listed states is detected, the local controller notifies the global controller, which selects the destination servers to host the virtual machines via migration. It is proposed to place virtual machines based on the criteria of minimum remaining unused resources and violation of SLA agreements. A mathematical formulation of the optimization problem is given, which is equivalent to the known main assignment problem in terms of structure, necessary conditions, and the nature of variables. Reducing the assignment problem to a closed transport problem allowed us to solve the problem of hosting virtual machines under many criteria in real time and significantly increase its dimension in comparison with heuristic algorithms, which makes it possible to maintain the quality of modern cloud services in the conditions of rapid growth of physical and virtual resources of data centers. The developed mathematical formulation of the problem and the results of computational experiments can be included in the mathematical software of virtual machine live migration.
ANALYSIS OF FAST ALGORITHM OF MATRIX-VECTOR MULTIPLICATION FOR THE BANK OF DIGITAL FILTERS
Authors:   Moscow Technical University of Communications and Informatics, Kreyndelin Vitaly B. , Grigorieva Elena D. ,   Moscow Technical University of Communications and Informatics
Published: October 2021

Algorithms of implementation of vector-matrix multiplication are presented, which are intended for application in banks (sets) of digital filters. These algorithms provide significant savings in computational costs over traditional algorithms. At the same time, reduction of computational complexity of algorithms is achieved without any performance loss of banks (sets) of digital filters. As the basis for the construction of algorithms proposed in the article, the previously known Winograd method of multiplication of real matrices and vectors and two versions of the method of type 3M for multiplication of complex matrices and vectors are used. Methods of combining these known methods of multiplying matrices and vectors for building digital filter banks (sets) are considered. The analysis of computing complexity of such ways which showed a possibility of reduction of computing complexity in comparison with a traditional algorithm of realization of bank (set) of digital filters approximately in 2.66 times – at realization on the processor without hardware multiplier is carried out; and by 1.33 times – at realization on the processor with the hardware multiplier. These indicators are markedly higher than those of known algorithms. Analysis of sensitivity of algorithms proposed in this article to rounding errors arising by digital signal processing was carried out. Based on this analysis, an algorithm is selected that has a computational complexity smaller than that of a traditional algorithm, but its sensitivity to rounding errors is the same as that of a traditional algorithm. Recommendations are given on its practical application in the development of a bank (set) of digital filters.
DETERMINATION OF CHARACTERISTICS OF UNDERWATER AUTONOMOUS APPARATUS TRANSITORY TO THE DOCKING MODULE FOR HNS WITH ULTRASHORT BASE
Authors:   Novosibirsk State Technical University, Filippov Boris I.
Published: October 2021

The expediency of creation of the apparatus of the high-frequency hydroacoustic system of transformation in the form of the jointed information and navigation system combined on base of antennas of system in which hydroacoustic navigation systems with ultrashort base can be used is reasonable; it is offered to use signals of data which the docking module and autonomous underwater apparatus exchange by results of measurement of mutual navigation characteristics as navigation. In a point of reception signals are observed reflected from a bottom and surface in the presence of reflecting surfaces which can be with a small depth of water area compared to horizontal distance to SA. The sizes of the reflected signals will depend on effective areas ground and superficial scatterings, which depend on a mutual positioning of DM and SA at the depth of the water area. The spatial correlation of scattered signals renders the greatest influence in the mutual correlation processing of signals from the elements of antenna of HNS. The coefficient of correlation scattered component will be so small that it will give practically no displacement of the bearing estimate at the wave size of the antenna of HNS about 10l. At the small wave sizes of the antenna (commensurable with l) the coefficient of spatial correlation of hindrance can render noticeable influence on the estimate of a difference of phases of a navigation signal from exits of elements of the antenna of HNS. This influence affects especially strongly at estimate of corner of place. The size of the displacement of the estimate will be proportional to the size of the signal reflected from the surface of the water area and coefficient of its spatial correlation. When approaching the SA to the DM, there can be re-reflections of a navigation signal from elements of their constructions. At the radius of a nasal part of SA 0,2 meters the relation of levels will make about 30 dB. Displacement of estimate of difference of phases of signals will be only when there is an angular displacement at reflections (there is not symmetry at a reflection). However, even then influence of the re-reflected signal is small. Considering that the header of the information signal has the same volume of uncorrelated selection as an information signal we receive the relation a signal/hindrance at the input of the decisive scheme, equal 240, that exceeds necessary value for the set accuracy of definition of navigation characteristics.
METHODOLOGY FOR CALCULATING THE ECONOMIC EFFICIENCY OF CONNECTING END-USERS OF MESH WIRELESS NETWORKS TO THE GLOBAL NETWORK
Authors:   Altai State University, Danko Evgeniy V. , Konstantunova Olga V. ,   Altai State University, Ternovoy Oleg S. ,   Altai State University
Published: October 2021

This paper explores the cost-effectiveness of various ways to connect users to the Internet. Three methods are analyzed: cable connection, GSM connection and Wi-Fi mesh connection. For these methods, a mathematical model is constructed that allows you to evaluate: return on investment, company profits, risk fear ratios and regrets about lost profits. The indicated calculations are carried out for 100 users in each connection method. The study of economic efficiency will be carried out by assessing the values of the parameters NPV, PI and IRR. According to the classical approach to assessing the effectiveness of projects, when implementing projects in cities, a connection using Wi-Fi mesh networks has higher relative project performance indicators (PI and IRR), but a lower NPV indicator than a project for a cable connection to the Internet. In conditions of low population density, the project for the implementation of the Internet by Wi-Fi mesh networks is more profitable in all considered indicators (NPV, PI, IRR) than the project for the implementation of the Internet via cellular communication.
APPLICATION OF NETWORK MODELS IN SOCIAL AND ECONOMIC SYSTEMS
Authors:   Peter the Great St. Petersburg Polytechnic University (SPbPU), Burlov Vyacheslav G. , Grachev Mikhail I. ,   St. Petersburg University of the Ministry of Internal Affairs of Russia
Published: October 2021

In modern conditions, there is a widespread introduction of digital information technologies in all spheres of society and, as a result, in social and economic systems, such as the education system. Web technologies and other hardware and software systems are being introduced into the process of functioning of an educational institution. As a result of the increasing spread of destructive impact on information web-resources (sites), the need for timely decision-making by a decision-maker (DM) has increased to counteract this impact. A goal such as uninterrupted management for the head of the organization is a priority task in various social and economic systems. Accordingly, in order to achieve the goal of management, it is necessary to have a properly constructed model that allows you to respond in a timely manner to the negative influences of the external environment. The development and subsequent application of methods and techniques that allow achieving the set goal in a shorter time will always be relevant and in demand. For a rational approach to making management decisions, a manager can use network planning, which serves as a plan for conducting the entire cycle of information security processes, both a website and the work of the organization as a whole. The article discusses a method based on network work planning, which allows for a more detailed consideration of planned activities and events, identify weaknesses and reallocate time resources to achieve the required management goal. In the work, it is proposed to link time characteristics with the states of planned works and events, in the form of using network modeling of four processes. An analysis of the weaknesses is carried out, the time reserves necessary to achieve the goal of management and the continuous work of the web resource are redistributed. The proposed method allows us to consider the probability of events and facts in order to improve the likelihood of achieving the goal of management by decision makers in the social and economic system.
DEVELOPMENT AND ANALYSIS OF A BLOCKCHAIN SYSTEM BASED ON JAVASCRIPT
Authors:   SPbGUT, Elagin Vasiliy S. , Fedorovskikh Vladimir I. ,   SPbGUT, Spirkina Anastasia V. ,   SPbGUT
Published: October 2021

The paper describes the main features of blockchain technology, provides the main areas of use of this technology. Today, blockchain has evolved into a reliable and secure way to store and record transactions across a wide range of application domains. However, the impact of existing solutions on the current network infrastructure needs to be considered. The authors propose to create a system for generating and storing blockchain traffic based on the JavaScript programming language. This solution cannot be applied to cryptocurrencies, but it allows you to evaluate the work of a distributed database based on blockchain technology. The aim of the work is to analyze the delays in the generation and distribution of traffic between various numbers of nodes and the dependence of the speed of distribution and block generation on the performance of computers. The paper also considered the algorithm for joining a new node to the cluster and sending a new block to the blockchain, as well as the scheme of a node in a blockchain cluster, and presented the results of an experiment with a quantitative assessment of network performance characteristics.
CHANNEL ESTIMATION FIELD DESIGN FOR THE SINGLE CARRIER MODULATION IN IEEE 802.11AY
Authors:   Radio Gigabit LLC, Gagiev Yaroslav , Aderkina Anastasia ,   Radio Gigabit LLC
Published: October 2021

This paper describes structure of a channel estimation field for the single carrier (SC) modulation based on the IEEE 802.11ad standard supporting transmission of radio signals between devices with multiple antennas for transmission and reception (MIMO – Multiple Input Multiple Output). Channel estimation field design uses a developed set of reference sequences based on complementary Golay pairs having similar statistical characteristics. All sequences are orthogonal to each other and each complementary pair has a pair in the set with zero cross-correlation property between them. Usage of this property allows to cancel out interstream interference during channel estimation procedure. A key property of the developed set is a common hardware architecture for a generator and correlator. Proposed structure of the channel estimation field is flexible and can be extended to arbitrary number of spatial streams for transmission. To analyze influence of the proposed channel estimation field on system performance, dependence of packet error rate on signal to noise ratio (SNR) was simulated for MIMO configuration with two transmit and two receive antennas for real and ideal channel estimations. System performance is analyzed in two channel models: the line of sight channel and the Rayleigh channel corresponding to the best and worst case of the signal propagation. It was shown that degradation of the SNR operating points depending on a modulation-coding scheme is in range 0.6-1.1 dB for the line of sight channel model and 0.7-1.5 dB for the Rayleigh channel model. This solution is already adopted by the IEEE 802.11ay standardization group.
MONITORING SYSTEM FOR LTE-A CELLULAR COMMUNICATION NETWORK ACCESSIBILITY INDICATORS
Authors:   Kazan National Research Technical University named after A.N. Tupolev-KAI, Fadeev Vladimir , Zaidullin Shaikhrozy ,   Kazan National Research Technical University named after A.N. Tupolev-KAI, Fadeeva Zlata ,   Kazan National Research Technical University named after A.N. Tupolev-KAI, Nadeev Adel ,   Kazan National Research Technical University named after A.N. Tupolev-KAI
Published: October 2021

In this paper we consider two accessibility indicators, namely E-RAB (E-UTRAN Radio Access Bearer) and E-RRC (Evolved Radio Resource Control) failure rates, of the LTE-A communication network belonging to one of the regional operators in Russian Federation. The aim of this study is to find the proper algorithms for accessibility indicators prediction, and performance estimation of these algorithms. During the study, we provide temporal dynamics of the indicators and possible failure reasons, behind these indicators. Then the percentage of the time series values is shown, which are corresponding to the abnormal situations (incidents). After that, the stationarity of the inspected time series using augmented Dickey-Fuller (ADFuller), and Kwiatkowski-Phillips-Schmidt-Shin (KPSS) methods is analyzed. Next, the ETS decomposition is performed. In order to predict the future values of the indicators, we utilize SARIMA model, triple Exponential Smoothing (Holt-Winters method), Facebook Prophet, Prony decomposition based model and XGBoost algorithm. Performance estimation is obtained in two ways: by test-sequence- and cross-validation-based Median Absolute Error (MAE). Also, the architecture for the monitoring system, that collects, analyzes and visualizes the required metrics within the infrastructure of the considered operator, is proposed in this paper. Herein, we analyze the possibilities of the open-source solution deployment on each stage of the monitoring process from data mining and preparation up to predictive model learning.
MODEL OF INSTANTANEOUS FREQUENCY MEASUREMENT RECEIVER WITH PRELIMINARY FREQUENCY MULTIPLICATION AND AUXILIARY CHANNEL BASED ON NONLINEAR SCATTERING PARAMETERS
Authors:   Samara University, Atkishkin Sergey F.
Published: October 2021

The article deals with instantaneous frequency measurement (IFM) receiver model. Proposed receiver exploits preliminary frequency multiplication of input signal and auxiliary microwave detector channel. Article goal is investigation of microwave transfer coefficient irregularity compensation method. Another goal is investigation and reduction of measurement error sources. Research goals are reached by mathematical model construction and it further investigation. Mathematical model is based on the nonlinear large signal scattering parameters. Model demonstrates that preliminary frequency multiplication allows reduction of required group delay time of delay line. It is showed that measurement result affected by transfer coefficient irregularity, transfer coefficient instability of receiver chain elements and multiply reflected from irregularities waves. Auxiliary measurement channel and measurement function in the form of voltage ratio at basic channel detector and auxiliary channel detector provide a way to reduce influence of input signal amplitude, instabilities and irregularities of transfer coefficient on the frequency measurement result. It is showed that full reduction of aforementioned factors prevented by parasitic harmonics and multiply reflected waves. Required suppression level of parasitic harmonic are presented. Obtained results can find applications in sphere of electronic warfare and measurement theory and techniques.
ANALYSIS OF THE PARAMETRIC SENSITIVITY OF THE METHOD FOR OPTIMIZING THE STRUCTURE OF SPECTRALLY EFFECTIVE RADIO SIGNALS
Authors:   Voronezh Institute of the Ministry of Internal Affairs of Russia, Pechnikov Sergei S. , Sherstyukov Sergey A. ,   Voronezh Institute of the Ministry of Internal Affairs of Russia
Published: October 2021

Currently, increasing the speed of information transmission in wireless communication networks is a topical issue. The growing demand for spectral efficiency in radio communication systems gives rise to the introduction of signals with amplitude-phase modulation. Despite all its advantages, signals with vector modulation are characterized by a change in the envelope, which makes it impossible to use highly efficient nonlinear power amplifiers. Energy efficiency is clearly a critical factor in portable radio communications systems, where power supplies are often used in small packages, and the presence of energy losses due to heat dissipation is a significant drawback that requires additional cooling systems. In this connection, when developing modern radio communications, radio engineers are faced with the contradictory task of achieving maximum energy and spectral efficiency. One of the approaches to reduce nonlinear distortion of vector modulation is the use linearization schemes for nonlinear power amplifiers. This work is devoted to increasing the energy and spectral efficiency of signals with amplitude-phase modulation. The article discusses the restrictions imposed on the input signals for the method for optimizing of structure of spectrally effective radio signals with vector modulation, the formation of the output signal, the influence of phase shifters phase imbalance on p/2, the index of balance modulation, and the analysis of parametric sensitivity. The possibility of using quadrature modulators to form components with phase modulation and constant envelope is considered. This method was simulated and the effect of phase imbalance on the shape of the output signal constellation was revealed.
A NEW GENERATION OF CONTROLLED OPTIC SWITCH
Authors:   Azerbaijan Technical University, Hasanov Mehman Huseyn , Agayev Nadir Bafadin ,   Azerbaijan Technical University, Atayev Nadir Arzu ,   Azerkocmos” OJSC, Fataliyev Vali Muxtar ,   Azerbaijan Technical University
Published: October 2021

Optical switches (OS) are widely used for switching optical signals in optical networks. Parameters and technical characteristics of OS include its capacity, number of inputs and outputs, speed of transition from one state to another, optical losses during signal transmission in the channel (value of attenuation coefficient in “on” state) and switching obstacles or switch off (in “off” state) the value of the extinction coefficient) and so on. The article proposes a new design of a new generation 3D switch based on a comparative analysis with other optical switches to create a high-speed and efficient optical transition in optical networks. The working principle of the proposed 3D switch is explained and a new structural block diagram is developed. The efficiency probability of the elements ensuring the stable operation of the proposed optical switch was calculated, calculations were performed in the MATLAB environment, and graphs of the probability of unrejected operation of the device were constructed.