bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of the River Network of Flooded Areas with a Univariate Model upon Water Posts Maximal Levels According to the Sura River SKIOVO (Scheme of Water Bodies Integrated Use and Protection) Experience
Authors:   Sidorov N.P.
Published: October 2021

A method of the flooded area calculation with an invariate model of a braided river network upon maximal water levels of different expected probability known for water-measuring stations has been presented. This method application has been demonstrated in conjunction with implementation of the “Scheme of water bodies integrated use and protection” for the Sura River basin with the use of GIS-technologies and digital topographic maps of 1:100 000 scale for derivation of the relief model and the river basin network hydrodynamic model, for identification of flooded zones and protected areas on the territory of the basin.
Creativity and Parental Involvement in Early Childhood Education in the Reggio Emilia Approach and Philosophy
Authors: Kołodziejski Maciej , Butvilas Tomas
Published: October 2021

In the article the authors discuss the importance of parental creativity and involvement in early institutional education of a child on the example of Reggio Emilia educational method. Among the main aspects of this involvement are the quality of education, child support, cooperation between teachers and parents as well as a positive feedback. The authors of this paper also deal with one of the main aspects of early education—creativity and its importance for a child’s psychosocial development. The preschool curriculum has been designed for children of the preschool educational institutions to provide them with a rich learning experience and to help them to develop properly. Creative education starts at an early age, therefore kindergartens and families play a very important role in supporting and developing creativity in child’s everyday routine. It is stressed that being creative is primarily about taking initiatives and innovative behavior. These are the qualities required in contemporary society, especially by employers in private and public sectors. However, the process of involving parents in their child’s education starts at the preschool stage and plays the most important role in child’s socialization. It is also emphasized that if children feel the support of both educational subjects (teacher and parents) in the process of preschool education, they feel safer, more comfortable, and much more confident.
DAMAGE TO THE BILE DUCTS AFTER LAPAROSCOPIC CHOLECYSTECTOMY. REVIEW.
Authors: Doskhanov Maxat
Published: October 2021

This article provides a review of the literature on bile duct injuries after laparoscopic cholecystectomy. Laparascopy is considered the gold standard in the treatment of gallstone disease. This technique has a number of positive advantages: minimally invasiveness, quick rehabilitation, a shorter hospital stay, a good cosmetic effect, and a low lethal outcome. Along with these advantages, the number of complications also increased: damage to the bile ducts, hepatic vessels, bile leakage, formation of strictures, defects in drainage of the biliary tract and improper treatment of the cystic duct, insufficient drainage of the abdominal cavity. Today, many aspects of surgical treatment and prevention of bile duct injuries remain controversial and are still considered relevant. The main reasons for this complication are: lack of experience of the surgeon, inattention, ignorance of the main options and possible anomalies of important anatomical structures in the area of the hepatic hilum and hepato-duodenal ligament, technical errors.
TYPES OF CORRECTION OF THE SUPRACARDIAC FORM OF PARTIAL ABNORMAL DRAINAGE OF THE PULMONARY VEINS. WARDEN PROCEDURE
Authors: Sagatov Inkar , Dosmailov Nurzhan
Published: October 2021

The article describes the types of correction of the supracardial form of abnormal drainage of the pulmonary veins. One of the methods of correcting this defect is the Warden operation, which includes: after sternotomy, connection of artificial circulation, cardioplegia, the superior vena cava is cut off, the proximal end is sutured. Next, a right atriotomy is performed, an anastomosis is formed using an autopericardial patch between the abnormal drainage and the left atrium through the ASD. Then an anastomosis is formed between the auricle of the right atrium and the distal end of the superior vena cava. As a result, blood from the abnormal pulmonary veins begins to drain into the left atrium through the ASD.
EVALUATION OF THE EFFECTIVENESS OF A CLOSED CIRCUIT IN COMPARISON WITH AN OPEN CIRCUIT OF CARDIOPULMONARY BYPASS
Authors:   JSC «A.N. Syzganov National Scientific Center for Surgery», Almaty, Kazakhstan, Tuishiev Berik , Bayzhan Gulzhan , Samitova Sabina
Published: October 2021

Objective is to evaluate the effectiveness of closed-loop surgeries with the planned duration of cardiopulmonary bypass more than 2 hours in the immediate postoperative period. Materials and methods. A study was carried out in the clinic over 10 patients (average age 47-56 years) with Diagnoses: Ascending aortic aneurysm, FC 3 aortic valve insufficiency, who underwent surgery for ascending aorta replacement, aortic valve replacement with coronary artery reimplantation. The patients were divided into 2 groups, the 1st group (5 patients) is the control group using an open cardiopulmonary bypass circuit, the 2nd group (5 patients) is the patients using a closed cardiopulmonary bypass circuit. The total time of cardiopulmonary bypass in both groups was 125-187 minutes. Results. In the 2nd study group, drainage blood loss significantly decreased, on average 60-100 ml compared to the control group, where the average drainage loss was 600-1500 ml. The need for blood transfusion was 5.1% in the 2nd group, compared with 43.4% in the control group. In the study group 2, the number of platelets in the postoperative period in patients was higher than in the control group. Conclusion. This study shows that a closed circuit, compared to an open one, allows complex heart surgeries with a planned duration of extracorporeal circulation of more than 2-3 hours.
Employer branding and employee value proposition: The key success of startup companies in attracting potential employee candidates
Authors:   Department of Management Economics, Faculty of Economics and Business, UPN “Veteran” Jawa Timur, Surabaya, Indonesia, Ariyanto Rizqi , Kustini Kustini ,   Department of Management Economics, Faculty of Economics and Business, UPN “Veteran” Jawa Timur, Surabaya, Indonesia
Published: October 2021

Abstract Purpose: This study aims to analyze employer branding and employee value proposition on employer attractiveness in potential employee candidates of Startup Campuspedia Indonesia. Research methodology: This study uses quantitative research methods that are processed using Smart PLS software. The sampling technique used is proportional random sampling with a total of 51 samples. Results: The results show that employer branding and employee value proposition have a positive and significant impact on employer attractiveness at Startup Campuspedia Indonesia. Limitations: The limitation of this study is that it only uses one startup company in the field of education as the object of research and has not used several companies with different backgrounds. Contribution: The results of this study can be useful for Human Capital in the company's recruitment process in the next period as an effort to increase the interest of prospective employees to work in the company.
Revisiting nation branding: An infrastructure financing perspective in Zimbabwe
Authors:   Business Science, College of Business, Peace, Leadership and Governance, Africa University, Mutare, Zimbabwe, Chigora Farai , Kapesa Tonderai ,   Finance and Accounting Department, Faculty of Business and Economic Sciences, Harare, University of Zimbabwe, Svongoro Paul ,   Department of Humanities, Faculty of Social Sciences, Theology, Humanities and Education, Africa University, Mutare, Zimbabwe
Published: October 2021

Abstract Purpose: This study aimed to reconfigure nation branding theories and concepts through infrastructure financing intervention. Research methodology: Data were collected using a QUAL to QUAN sequential mixed methods. Results: Qualitative research informed that the infrastructure that is required for nation branding to be road networks; airports; Information Communication Technologies (ICTs); reliable power supply; industrial facilities; tourism facilities; healthcare facilities; educational facilities; educational facilities; and residential accommodation. These were then classified into two, namely, economic and social infrastructure. Results from quantitative research showed that there is a positive relationship between nation branding and infrastructure financing. Also, it showed that road infrastructure and airports were the most related to nation branding with public-private partnerships and bilateral/multilateral loans to finance their development, respectively. Limitations: As a result of the COVID-19, the research did not manage to have some focus groups for a depth understanding and comprehensive response of the participants. Contribution: The results will help the Zimbabwean government consider developing the road networks and airports to enhance the nation’s brand.
Leadership styles and employees' performance: A case of family-owned manufacturing company, Cape Coast
Authors:   School of Business, University of Cape Coast, Cape Coast, Ghana, Amegayibor Godson Kwame
Published: October 2021

Abstract Purpose: This study aimed to explore the association between leadership styles and employee performance in a family-owned manufacturing business. Research methodology: For data translation and analysis, the study used a quantitative approach and a correlational design, a census technique of sampling 400 employees, an interview schedule, multiple linear regression, and the Statistical Package for Social Sciences (SPSS) 16.0 Versions. Results: Results revealed that autocratic, charismatic, and paternalistic leadership styles influence employees' performance. The result also revealed that autocratic, charismatic, and visionary leadership styles influence error reduction. Again the result shows that paternalistic and visionary leadership styles influence employees' quality of work. Limitations: The study's main weakness is that it only looked at nine specific leadership styles and their effects on employee performance. Contribution: Given this, managers should consider using leadership styles with stronger predictions in a given situation to drive employees' performance, reduce employees' errors in work and enhance employees' quality of work.
The comparative analysis of FMCG enterprises' vision, mission, and core values focusing on strategic human resources
Authors:   Human Resource Management Discipline, Khulna University, Khulna, Bangladesh, Shanjabin Samia , Oyshi Amanta Hasnat ,   Human Resource Management Discipline, Khulna University, Khulna, Bangladesh
Published: October 2021

Abstract Purpose: This study focused on a comparative analysis of the FMCG enterprises' vision, mission, and core values focusing on strategic human resources. Research methodology: This study is qualitative, and altogether twenty-three FMCG company's websites have been used for analyzing the company's mission, vision, and core values. Results: Among the twenty-three companies, only seven (Bombay Sweets and Co. Ltd., Arla, Akij Group, Ispahani Foods Limited, Golden Harvest Agro Industries Limited, Walton Group, and City Group) have no focus on strategic human resources in their mission, vision and core values. Sixteen companies have a concern about strategic human resources in vision, mission, and core values. Limitations: This study only includes results from the FMCG of Bangladesh rather than including other industries like telecommunication, MNCs, and other areas. Again, this study is limited by including only a few FMCGs. Contribution: This study results contribute to strategic human focus in the vision, mission, and core values of FMCG enterprises of Bangladesh through a comparative analysis also emphasizes strategic human focus in the employees' development.
RHEUMATOID ARTHRITIS: ETIOPATHOGENESIS AND MOLECULAR BASIS
Authors: Bedolla Eliseo Ruiz , Lopez Martinez Briceida , Ortega Israel Parra
Published: October 2021

Rheumatoid arthritis (RA) is the most common form of inammatory arthropathy sustained by autoimmune responses. This review has the objective of updating the knowledge about RA especially its molecular pathogenesis. We examine here the current knowledge of tryptophan, arginine, homoarginine and histidine metabolism and the main immunoregulatory pathways in amino acid catabolism in both RA patients and experimental models of arthritis. Of the characteristic autoantibodies of RA, those that appear earlier, are those that recognize cyclic citrullinated peptides. (CCP) and/or citrullinated brinogen. Therefore our analysis would indicate that amino acids metabolism represents a fruitful area of research for new drug targets for a more effective and safe therapy of RA.
A COMPARATIVE STUDY OF PALEOLITHIC PERIOD OF SOUTH ASIA AND EAST ASIA
Authors: Padmaja Marri , Rangaswamy B. K.
Published: October 2021

E.B. Tylor and L.H. Morgan postulated that man kind as a whole has
passed through the stages of savagery, barbarism and civilization.
Tylor did n'st place specic cultures into different stages of cultural
development of human beings, but Morgan subdivided the stage of
savagery and barbarism each in to three groups , namely lower, middle
and upper. He was of opinion that lower savagery began with
development of language and gathering of fruits and nuts
assubsistence. This stage ended with development of shing
subsistence and use of re. No living example can be citedto this
stratum.
High-performance Pixel-level Grasp Detection based on Adaptive Grasping and Grasp-aware Network
Authors: Dexin Wang
Published: October 2021

A pixel-level grasp detection method. https://youtu.be/ccA1jkkbBJA
Lo spirito di Arcetri
Authors: Casalbuoni Roberto , Dominici Daniele , Mazzoni Massimo
Published: October 2021

On 7 November 1921, the new Institute of Physics of the Royal Institute of Higher, Practical and Advanced Studies of Florence was inaugurated in Arcetri. Three years later, with the establishment of the University of Florence, the Degree Course in Physics would start: as such an adventure in research and scientific training began, which would take us to the present day. To mark the centenary of the inauguration of the Institute of Physics in Arcetri, the book takes the opportunity to retrace a part of those years. The period chosen ranged from the arrival of Garbasso in 1913 to the end of the 1960s. The book contains a first part, documenting the history of the Institute of Physics during the above mentioned years. This is followed by a second part, outlining the biographies of some of the protagonists of that history. In the final part, there is an index of the holders of the courses of Physics and Astronomy in Florence from 1876 to 1969. This landscape is the result of research work conducted in the University’s Historical Archives of the University.
Chemical profile, antioxidant and photoprotective activities of essential oil and crude extracts of Algerian Thymus serpyllum
Authors: Madouni Nariman , Meddah Boumediene , Aicha Tir Touil , Bensouici Chawki , Cakmak Yavuz S , Piras Alessandra , Falconieri Danilo , Sonnet Pascal
Published: October 2021

Thymus serpyllum is an aromatic and medicinal plant widely used in Algerian folk medicine. It was collected from Mascara region North West of Algeria and studied in the aim to provide more knowledge about chemical composition, antioxidant and photo-protective activities of essential oil, ethanolic and infusion extracts. The chemical analysis of investigated T. serpyllum EO was performed for the first time in this research work. It was carried out by GC/MS for identifying 25 components where the dominated compounds were Carvacrol (66%) and γ–Terpinene (11.5%). The phenolic profile of ethanolic and aqueous infusion extracts was performed using HPLC chromatography and the data showed the Benzoic acid and Rosmarinc acid were found as major compounds. Extracts showed an excellent source of total phenols and flavonoids. Antioxidant activity was evaluated using DPPH, Galvinoxyl radical (GOR), CUPRAC, reducing power and O-phenanthroline approaches. All extracts showed a significant antioxidant capacity with different mechanisms. However, ethanol and infusion extracts showed stronger capacity than EO. Moreover, the photoprotective activity of T. serpyllum extracts was explored for the first time in our study. Extracts exhibited high values of sun protective factors (SFP) with 38.34±2.29 and 38.82±2.23 for ethanol and infusion extract respectively. Results of our study may encourage the pharmacologic, food and cosmetic sectors to use the wild thyme as natural and healthy source of active compounds.
FEATURES OF TIME SERIES USING FOR ESTIMATION OF FLUCTUATIONS OF CAR TRAFFIC VOLUMES AT THE RAILWAY DIVISION POINTS
Authors:   Irkutsk State Transport University (IrGUPS), Malovetskaya Ekaterina V. , Bolshakov Roman S. ,   Irkutsk State Transport University (IrGUPS)
Published: October 2021

The study of intra-annual dynamics of car traffic volumes, handed over at the railway division points of the Russian Federation is an essential part of the long-range prediction, planning and analysis of transport activity. The increase in the regularity of pace of the production process is directly related to the assessment of the unevenness of car traffic volumes. The ability to predict the unevenness of the transport process, as well as uneven loading with the establishment of relevant indicators is a key issue in the regularity of pace of transport operation. The presented article analyzes the structure of time series of fluctuations in car traffic volumes at the railway division points in order to further build a model for predicting fluctuations in car traffic volumes and, in the future, loading cargo to the ports of the Far East. This methodology is based on the analysis of the structure of time series of fluctuations in car traffic volumes handed over at the railway division points and moving further towards seaports with the subsequent construction of a mathematical model of cargo loading, on the basis of which it will subsequently be possible to predict the loading for the coming year. The presented work considers an analysis of the structure of time series of fluctuations in car traffic volumes and proposes models for the subsequent construction of a prediction. It also applies a systemic approach to solving the problem of predicting the car traffic volume. The proposed tools make it possible to develop prediction models to assess the seasonal unevenness of cargo loading in the direction of seaports. All this will contribute to the improvement of logistics planning of transportation and will give a further impetus to the development of the industry. The whole range of activities consists in the possibility of constructing predictive models for the production unit of the Russian Railways holding. In addition, it will be possible to update the structure of the network’s operational indicators.
DISPERSION DISTORTION TRACKING COMPENSATOR BASED ON THE SIGMA-POINT KALMAN
Authors:   Moscow Technical University of Communications and Informatics, Lobov Evgeniy M. , Priputin Vladimir S. ,   Moscow Technical University of Communications and Informatics, Lobova Elizaveta O. ,   Moscow Technical University of Communications and Informatics, Liberman Efim A. ,   Moscow Technical University of Communications and Informatics
Published: October 2021

The article proposes an algorithm for nonlinear optimal filtering of the dispersion characteristic slope of the ionospheric channel (DC slope) based on the Kalman sigma-point filter when sounding the channel with broadband signals. The relevance of the applied algorithm can be explained by the fact that at present in the modern world the relevance of the transmission of broadband information signals in the decameter range has increased. The reception of such signals is complicated by the effects caused by the influence of the frequency dispersion of the ionospheric channel on the signal. The above influence leads to significant distortions of the useful signal and a decrease in the quality of information reception in general. The above influence leads to significant distortions of the useful signal and a decrease in the quality of information reception in general. Therefore, the effect of frequency dispersion cannot be neglected and must be taken into account when developing algorithms for optimal reception. Thus, estimation of the parameters of the frequency dispersion of the ionospheric channel becomes an urgent task. The article provides recurrent formulas for calculating the optimal filtration of the DC slope. Moreover, an algorithm for joint estimation of dispersion distortions and their compensation is presented, which allows improving the quality of estimation. The results of simulation modeling of the algorithms are given: the obtained estimate and the true value of the frequency dispersion parameters for two cases – a Markov damped process and a process with random increments. The absolute error in estimating the DC slope is also considered. The computational efficiency of the algorithm for estimating the DC slope using the Kalman sigma-point filter with and without compensation is calculated. In addition, functional diagrams of optimal filtering of the DC slope with compensation and without compensation are given. The ways of implementing the proposed algorithm on an ARM processor are considered.
IMPLEMENTATION OF IOT TECHNOLOGY FOR DATA MONITORING VIA CLOUD SERVICES
Authors:   Moscow Technical University of Communications and Informatics, Antonova Veronika M. , Malikova Elena E. ,   Moscow Technical University of Communications and Informatics, Panov Alexey E. ,   Moscow Technical University of Communications and Informatics, Spichek Igor V. ,   Moscow Technical University of Communications and Informatics, Malikov Andrey Y. ,   Moscow Technical University of Communications and Informatics
Published: October 2021

An operating device has been designed for long term aggregating, storing and visualizing climate records with a view to their further publication in a cloud service. In order to address the given problem a number of technical issues related to the device concept development and its operating algorithms were solved. The device runs using the MQTT protocol and a microcontroller unit based on ESP8266 chip which is designated for the application in Internet of Things (IoT) devices. The designed system is based on open-source software and allows providing access to the received data to all authorized users. The system is expanded easily since the number of attached sensors and peripheral units can change and the program can be transformed so as to solve emerging tasks. The ability to connect the Internet from any access point provides the mobility for the device and permits to make measurements within the range of a Wi-Fi network. In some instances, it is convenient to use smart phones or tablets that have access to the Internet via cellular networks for research and scientific experiments. In this case, mobile devices can act as monitors to control the system operation. This device can be useful for carrying out research work when data collection over a long period of time and long-term storage of information with the possibility of its further processing are essential. The examples are automatic monitoring of the equipment, medical supervision of patients’ health or gathering and processing of various climate parameters. Undergraduate students can also make use of the developed device when studying IoT technology.
ESTIMATION THE NOISE IMMUNITY OF CONTINUOUS PHASE MODULATION SIGNALS WITH FULL RESPONSE BASED SIMULATION MODEL
Authors:   Military Academy of the Strategic Missile Forces named after Peter the Great, Azarov Andrey I. , Budarin Evgenyi V. ,   West Department of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences
Published: October 2021

The problem of spectral load of communication channels is now becoming urgent, which determines the efforts of the world’s leading tech communication companies to search for perspective signals. These signals must ensure compliance with international standards governing the use of frequency bands and the permissible level of out-of-band emissions and the required noise immunity of information transmission. The article deals with the noise immunity of continuous phase modulation signals research. A preliminary estimation is carried out by calculating the Euclidean distances between signals. The estimates of the noise immunity were obtained experimentally. The results of simulation are presented for fixed value of the signal to noise ratio for signals. Modulation indices and phase pulse were taken into account. The results of the study make it possible to emphasize the modulation indices for CPM FR signals, having more noise immunity then the known BPSK and MSK signals. Increasing the noise immunity becomes possible due to intersymbol phase communication. These signals are received according to the Viterbi algorithm. The results of the study show the values of the modulation indices to be of practical interest.
MODEL OF HETEROGENEOUS LOCAL COMMUNICATION NETWORK WITH SYNCHRONOUS TIME ACCESS PROTOCOL, CONSIDERING THE RELIABILITY OF ITS ELEMENTS
Authors:   Azerbaijan Technical University, Gezalov Elchin B.
Published: October 2021

In the article the local communication network, heterogeneous on the intensity of the incoming message flow and the type of messages, with synchronous time access protocol is considered. All communication stations of the considered local network consist of three substations: speech substations, video information substations and data substations. Speech substations form the speech subnet, video information substations form the video information subnet, and data substations form the data subnet. Substations within the same subnet are homogeneous in their activity. A model of the considered local network in discrete time is being carried out, which allows assessing the effect of the failure processes and restoration of substations of network stations and the communication channel on its characteristics. Based on the developed model of the local network, the probability-time characteristics of the considered network are selected and determined.
METHOD FOR CONSTRUCTING NONLINEAR WAVELET CODE TO ENSURE DATA INTEGRITY IN COMMUNICATION CHANNELS
Authors:   Krasnodar higher military school named after General of the army S. M. Shtemenko, Kuznetsov Nikolay A.
Published: October 2021

A method for constructing a nonlinear wavelet code (NVC) to ensure data integrity in communication channels, taking into account current threats to information security in a modern dynamic stochastic environment, is proposed. A special place among the methods of combating threats to the integrity of information is occupied by noise-resistant encoding. The article presents a computationally effective method for ensuring data integrity in communication channels by using nonlinear transformations and wavelets. The approximation of the wavelet transform refers to the division of the signal into approximating and detailing components. Continuous and discrete wavelet transforms are widely used [2] for signal analysis in modern communication channels. The set of functions defining the wavelet transform belongs to the space of square-integrable functions on a straight line and provides a necessary condition for constructing constructions of nonlinear codes based on the theory of wavelet decomposition. As is known, in the process of wavelet analysis, the signal is decomposed along the orthogonal basis formed by shifts of the wavelet function. A distinctive feature of this approach is that convolution of the signal with wavelets allows us to identify the characteristic features of the signal in the area of localization of these wavelets. To perform computational calculations, you need a set of scaling function coefficients and a wavelet. The wavelet transform matrix depends on the coefficients of the scaling function. The results presented in the article describe a new approach to ensuring data integrity in communication channels using nvcs. A computational example is presented.
NOISE PROTECTION OF SPACE-BASED SYNTHETIC APERTURE RADAR BASED ON DIGITAL AFAR
Authors:   Moscow aviation Institute (national research University), Grigoryan Ararat K. , Yudin Vasily N. ,   Moscow aviation Institute (national research University)
Published: October 2021

The article deals with General questions about the definition of parameters, the calculation of which is necessary for choosing a method for organizing interference protection of a synthetic aperture radar (RSA), analyzes and notes the features of the construction and functioning of the RSA. The features of noise protection on radars of various companies are considered: COSMO-SkyMed -4 (Constellation of Small Satellites for Mediterranean basin Observation) X-band (made in Italy), TerraSAR-X/TanDEM-X (Germany), “Kasatka-R” (Russia). The subject of the study is a synthetic aperture radar, which is a coherent radar system that uses the flight path of the platform to simulate extremely large obstacles or objects electronically, and which generates high-resolution remote sensing images. Over time, individual transmit / receive cycles are completed, and data for each cycle is stored electronically. When the signal processing uses the amplitude and phase of the received signals in successive pulses from elements of a synthetic aperture. After a set number of cycles, the stored data is re-combined (taking into account the Doppler Effect inherent in different transmitters for the target geometry in each subsequent cycle) to create a high-resolution image of the terrain over which the flight is performed. The analysis of the RSA parameters that affect the radar noise immunity is performed. Objective: to analyze the interference protection of a space-based synthetic aperture radar based on digital AFAR. It is necessary to identify the type of interference that has an effective interfering effect on the protected object and determine their degree of impact depending on the parameters of the interference source. Noise immunity refers to the ability of a radio system to resist interference. Radars from various manufacturers have differential methods for improving noise immunity. The calculation of the radar range is given for the purpose of detailed consideration of the parameters of the maximum range of radio interference. The paper focuses on the main radar interference and options for improving noise immunity for this type of radar. Methodology: analysis of existing literature, analysis of technical characteristics of radars from various manufacturers, modeling of possible types of interference, deduction, induction, comparison of used radars with synthesized aperture, formalization.
DELAYS IN QUEUES OF QUEUING SYSTEMS WITH STATIONARY REQUESTS FLOWS
Authors:   Povolzhskiy State University of Telecommunications and Informatics, Likhttsinder Boris Ya. , Bakai Yulia O. ,   Povolzhskiy State University of Telecommunications and Informatics
Published: October 2021

During all periods of the study of telecommunications systems traffic, the analysis was based on mass service theory. The subjects of the study here are request flows to be processed by some limited performance resources. Resource constraints and the random nature of requests’ receipt lead to refusals in processing or queues. The first works devoted to the analysis of teletraffic belong to A. K. Erlang. Request flows represented flows of requests for connections in networks with channel switching. Since requests were received from a large number of independent users, the flows of such requests could be defined as stationary, ordinary with no effect, or as recurring requests, with an exponential distribution of time intervals between neighboring requests. Connection request flows to a telephone exchange node are a superposition of a large number of low-intensity flows from independent users. Therefore, the fixed Poisson flow model describes the real flows in telephone exchanges with channel switching quite well. Therefore, the stationary Poisson flow model describes real flows in telephone exchanges with channel switching rather well. The emergence of telecommunications networks with packet switching, especially multiservice networks, showed the impossibility of using Poisson flow models for their analysis. The article is devoted to the analysis of delays in queues of queuing systems with correlated stationary flows of general type requests. The traffic of packets in multiservice networks is typically characterized by a high degree of correlation. On the basis of interval methods of analysis, the relations generalizing the Khinchin-Pollaczek formula for the average value of waiting time in queuing systems with flows of the general kind of requests are obtained. The main parameters to be analyzed when outputting the above formulas are time intervals between neighboring requests. It is shown that the values of time delays in queues depend on the dispersion and dispersion index of a random value characterizing the degree of additional maintenance of processed requests.
REDUCING OF FEEDBACK CHANNEL INFORMATION IN MULTIPLE ANTENNA MIMO SYSTEMS
Authors:   MTUCI, Bakulin Mikhail G. , Ben Rejeb Taoufik ,   MTUCI, Kreyndelin Vitaly B. ,   MTUCI, Smirnov Aleksei E. ,   MTUCI
Published: October 2021

Multiple antenna systems MIMO (Multiple input multiple output) are widely used in LTE-Advanced mobile systems and in the IEEE 802.11 radioaccess standards. In the international standard of 3GPP for mobile communication systems 5G New Radio (Release 15), MIMO systems are regulated as a fundamental technology of the new Air interface. In this paper, we consider algorithms for quantization of information about the channel state using Grassmann manifolds, which significantly reduce the amount of channel state information required for transmission. The results of computer simulation allow to evaluate the noise immunity of precoding algorithms based on Grassmannian manifold quantization.
STATE ANALYSIS INTERNET OF THINGS DEVICES BASED ON BAGGING
Authors:   Saint-Petersburg federal research center of Russian science academy, Sukhoparov Mikhail E. , Lebedev Ilya S. ,   Saint-Petersburg federal research center of Russian science academy
Published: October 2021

The development of IoT concept makes it necessary to search and improve models and methods for analyzing the state of remote autonomous devices. Due to the fact that some devices are located outside the controlled area, it becomes necessary to develop universal models and methods for identifying the state of low-power devices from a computational point of view, using complex approaches to analyzing data coming from various information channels. The article discusses an approach to identifying IoT devices state, based on parallel functioning classifiers that process time series received from elements in various states and modes of operation. The aim of the work is to develop an approach for identifying the state of IoT devices based on time series recorded during the execution of various processes. The proposed solution is based on methods of parallel classification and statistical analysis, requires an initial labeled sample. The use of several classifiers that give an answer “independently” from each other makes it possible to average the error by “collective” voting. The developed approach is tested on a sequence of classifying algorithms, to the input of which the time series obtained experimentally under various operating conditions were fed. Results are presented for a naive Bayesian classifier, decision trees, discriminant analysis, and the k nearest neighbors method. The use of a sequence of classification algorithms operating in parallel allows scaling by adding new classifiers without losing processing speed. The method makes it possible to identify the state of the Internet of Things device with relatively small requirements for computing resources, ease of implementation, and scalability by adding new classifying algorithms.
APPLICATION OF MIMO TECHNOLOGY IN MODERN WIRELESS COMMUNICATION SYSTEMS OF DIFFERENT GENERATIONS
Authors:   Moscow Technical University of Communications and Informatics (MTUCI), Bakulin Mikhail G. , Kreyndelin Vitaly B. ,   Moscow Technical University of Communications and Informatics (MTUCI), Pankratov Denis Y. ,   Moscow Technical University of Communications and Informatics (MTUCI)
Published: October 2021

Multiple Input Multiple Output (MIMO) technology is widely used in modern IEEE radio access systems. There is a tendency to increase the number of antennas, which is also confirmed by the development of MIMO technology in mobile communication systems of 3GPP standards. Requirements for modern radio communication systems are constantly increasing. As the radio frequency spectrum becomes increasingly scarce, it becomes increasingly difficult to transmit large amounts of information by expanding the frequency channel bandwidth. Therefore, the use of MIMO technology to increase the spectral and energy efficiency of communication systems is relevant. In 5G systems, Massive MIMO technology is used, when using which the number of antennas is measured in tens and hundreds. The characteristics of various versions of MIMO technology implemented in the existing standards 802.11n, 802.11ac, 802.11ax, as well as in the promising standard 802.11be (6G systems) are described in detail. Technologies of directional transmission, spatial multiplexing, selection of antennas as particular cases of precoding are considered. Trends of MIMO technology development in wireless communication systems are shown.
METHOD OF AUTOMATIC TRANSMISSION OF THE INTEGRITY BREACH SIGNALS OF THE RIVER LOCAL DIFFERENTIAL SUBSYSTEM
Authors:   Admiral Makarov State University of Maritime and Inland Shipping, Ivanova Aleksandra A. , Shakhnov Sergei F. ,   Admiral Makarov State University of Maritime and Inland Shipping
Published: October 2021

The integrity of the navigation system is one of the important factors affecting the safety of navigation. Currently, on the inland waterways of Russia, alerts on the integrity of the GLONASS global navigation satellite system (GNSS) are transmitted through river local differential subsystems (LDSS), which include one or more reference stations. Industrial interference from industrial zones and power lines, mutual interference from neighboring reference stations and, especially, the inhomogeneity of the underlying surface affect the range of the reference stations, which leads to the integrity breach of the differential field and transmission of unreliable corrective information to the navigator. However, the navigator is not notified of the incorrect operation of the reference stations. As a result, inaccurate corrective information leads to errors in calculating the vessel position, which reduces the level of navigation safety. A method for the automatic transmission of notifications about the LDSS integrity breach from a remote control and management station (RCMS) to the ship is presented in the paper. The structure of the message transmitting the notification signal has been formed. Criteria characterizing the quality of the differential correction signal are presented. Possible combinations of such criteria, which determine the performance of the differential mode of the reference station, are identified. Each combination of criteria is juxtaposed the corresponding notification texts displayed on the monitors of the LDSS operators and on the navigator’s display. A scheme for the automatic transmission of an alarm message from a remote control point through the RCMS, the regional command and control center, the vessel traffic control center and base stations of the automatic identification system (AIS) to ship transponders has been developed. As a result, the developed method for transmitting the alarm message containing combinations of quality criteria for the differential correction signal allows to automatically inform the navigator about the reliability of the corrective information transmitted by one or another reference station.
COMPARATIVE ANALYSIS OF THE CONCEPT OF CREATION AND DEVELOPMENT OF 5G/IMT-2020 NETWORKS IN RUSSIA, CHINA, USA AND EUROPE
Authors:   ITMO University, Daneshmand Behrooz
Published: October 2021

This article raises the question of the prospects for the development of 5G networks in Russia, China, the United States and Europe. Currently, there are four distinct generations of cellular communication in the world and in Russia. The development of each subsequent generation of communication as technical and economic capabilities improved and the spread of dominant standards occurred approximately every 10 years. The research community and industry in general agree that in the future it is impossible to meet future mobile traffic demand and application requirements simply by evolving the current fourth generation architecture. Instead, there is a need for a significant overhaul of the mobile network system: such an effort is commonly referred to as the future fifth generation (5G) architecture, and large-scale initiatives have been launched around the world to address this issue. The research community has already invested a very significant effort in identifying new individual technologies. The fact that all new offerings are labeled 5G has created a lot of confusion about what 5G really is. The purpose of this article is to shed light on the current state of the definition of 5G architecture and trends in the required technologies in Russia, the United States, China and Europe. Key contributions are: (1) analyze the 5G requirements defined by various global initiatives, highlighting the similarities and differences in 5G network development in Russia, China, the United States and Europe; (2) discuss current technology trends showing that there is broad consensus on the key factors driving 5G development in these countries; (3) strive to understand the new concepts that need to be developed with assistive technology to meet the desired requirements.
THE CHOICE OF SIGNALS FOR HYDROACOUSTIC NAVIGATION SYSTEM OF TRANSFORMATION UNDERWATER APPARATUS TO DOCKING MODULE
Authors:   Novosibirsk State Technical University, Filippov Boris I.
Published: October 2021

The proposed work is the first part of the overall work on the development of the structure of the hydroacoustic navigation system (HNST) for bringing the autonomous underwater vehicle (AUV) to the docking module (DM). The second (final) part will be published in the next issue of the journal. The purpose of this work is to select signals for building HNST providing reduction in a near zone at the distances not exceeding 300 m, an AUV and its docking with the carrier is considered. Mutual definition of a distance and angular position DM of the carrier and AUV relative to each other is carried out for this purpose. Determination of mutual angular coordinates can be carried out with use of HNST with short and ultra-short base. HNST with short base is preferable for realization from the point of view of simplicity. However, its installation on the AUV can be impossible because of rather small sizes of the device, and on AUV should be installed HNST with ultra-short base. HNST with short base can be established on the docking module. Since there are no reasons to assume the high speed of change of the phase characteristic of the developed high-frequency channel of transformation therefore the interval of stationarity of the phase characteristic should be significantly more than duration of a symbol at a speed of transfer of 4 kBit/s. Therefore, it is advisable to exchange measurement data between AUV and DM in the composition of HNST by relative phase modulation (DPSM). Reception of signals is performed by a suboptimal incoherent receiver on which entrance deep restriction of an entrance signal is carried out. The use of deep signal limitation at the receiver input allows to exclude operation of automatic control of strengthening at a stage of entry into communication, as a result, it is possible to reduce the duration of communication sessions. In the combined information navigation system, it is expedient: to apply as navigation signals of data exchanged between AUV and DM based on the results of mutual measurement of navigation parameters; to carry out data exchange between AUV and DM by method DPSM with a speed V = 4 kBit/s; to carry out transfer of the block of data with application of the correcting block cyclic code ; to apply to reception of a block of data diversity reception in combination with majority decoding characters, and then correct errors in the data block with the help of code, and to accompany the issuance of data to the user sign detection code errors in the block.
EVALUATION OF THE INFLUENCE OF THE VALUE OF THE DYNAMIC RANGE OF THE RADIO RECEIVER ON THE NOISE IMMUNITY OF RECEIVING SIGNALS WITH QUADRATURE AMPLITUDE MODULATION
Authors:   Southwest State University, Dovbnya Vitaly G. , Koptev Dmitry S. ,   Southwest State University, Babanin Ivan G. ,   Southwest State University, Knyazev Alexander A. ,   Southwest State University
Published: October 2021

The improvement of digital communication lines of radio information transmission systems in the direction of increasing the complexity of the signal-code structures used, increasing the speed of information exchange, the use of modern channel compaction technologies, on the one hand, and the high complexity of the surrounding electromagnetic environment, on the other hand, objectively determines the need to improve the radio receiving systems of digital communication lines in the direction of increasing their noise immunity. In this regard, in order to justify the technical requirements for noise immunity to radio receiving systems of the designed transmission lines, it is advisable to take into account the basic indicators of the quality of functioning of the radio receiving device, in order to obtain analytical expressions and graphical dependencies for evaluating the noise immunity of receiving signals with more complex combined types of modulation (QAM-64 and higher), used and planned for use. Of the large number of indicators that characterize the dynamic range, the most informative and sufficiently characterize the quality of the linear path are: the dynamic range for reducing the transmission coefficient (compression) by 1 dB and the dynamic range for third-order intermodulation distortion. The effect of interference received on the side channels (which include combination and mirror), as well as on neighboring channels, limits the lower limit of the dynamic range of the receiving device and, as a result, reduces the resulting signal-to-noise ratio at the output. The degree of suppression of the combination channels is determined, first of all, by the frequency plan and the linearity of the amplitude characteristic of the mixer of the first frequency converter, the mirror channel – the quality of filtering the mirror frequencies in the input preselector, the neighboring channel – the selectivity of the filters of the main selection. In this article, an analytical model and the resulting graphical dependencies are developed to assess the degree of influence of compression distortions on the noise immunity of receiving multi-position quadrature-amplitude modulated signals, and the requirements for the value of the dynamic range of radio receiving systems are theoretically justified.