RESULTS OF MATHEMATICAL SIMULATION OF RELIABILITY OF PROJECTED SATELLITE COMMUNICATION STATIONS ON MOBILE OBJECTS

2021 ◽  
pp. 81-91
Author(s):  
Д.Г. Пантенков ◽  
В.П. Литвиненко
Keyword(s):  
Satellite Communication ◽  
Methodological Approach ◽  
Design Parameters ◽  
Radio Communication ◽  
Mobile Objects ◽  
System A ◽  
Fundamental Point ◽  
Fundamental Possibility ◽  
Marine Products ◽  
Upper Level

Современные сложные радиотехнические комплексы и системы входят в состав ракетно-космических, авиационных, сухопутных, морских изделий, обеспечивающих решение задач повышения обороноспособности и безопасности РФ, а также отвечающих интересам гражданских потребителей. При этом на этапе проектирования радиотехнических комплексов и систем закладываются требуемые расчетные параметры по надежности, безопасности, долговечности, технологичности в целях обеспечения требуемого срока их эффективного функционирования для решения поставленных целевых задач. Рассмотрены результаты математического моделирования надежности проектируемых станций спутниковой связи на подвижных объектах (космические аппараты, беспилотные летательные аппараты, автомобили, железнодорожные поезда), которые отражают методический подход к определению надежности комплекса или системы верхнего уровня. Принципиальным моментом является возможность определения числовых значений данного показателя еще на этапе составления тактико-технических (технических) заданий на выполнение НИОКР, проведения аванпроекта, т.е. тех этапах работ, на которых цена ошибки не является существенной и имеется принципиальная возможность внести изменения в конструктивные и схемотехнические параметры разрабатываемых радиотехнических комплексов и систем Modern complex radio communication and systems are part of rocket-space, aviation, dry-track, marine products that provide the solution of tasks both to increase the defense and safety of the Russian Federation and meet the interests of civilian consumers. At the same time, at the stage of design of radio engineering complexes and systems, the required design parameters for reliability, safety, durability, technological and technical support are laid in order to ensure the required period of their effective functioning to solve the set target tasks. This article considers the results of mathematical modeling of reliability of projected satellite communication stations on mobile objects (spacecraft, unmanned aerial vehicles, cars, railway trains), which reflect the methodological approach to determine the reliability of the complex or upper-level system. A fundamental point is the possibility of determining the numerical values of this indicator even at the stage of compiling tactical and technical (technical) tasks for R&D, conducting an advance project, i.e. those stages of work at which the error price is not significant and there is a fundamental possibility to make changes to the design and schematic parameters of the developed radio systems and systems

scholarly journals Methodological Approach to Integrated Effectiveness Assessment Apply of Aviation Systems with UAVs. Part 1. Evaluation Methods for Effectiveness of Solving Radio Communication and Remote Monitoring Tasks.

2020 ◽  
Vol 6 (2) ◽  
pp. 60-78
Author(s):  
D. Pantenkov
Keyword(s):  
Remote Monitoring ◽  
Methodological Approach ◽  
Practical Importance ◽  
Design Parameters ◽  
Radio Communication ◽  
Optoelectronic System ◽  
Industrial Enterprises ◽  
System A ◽  
Complex Target ◽  
Effectiveness Assessment

Currently, the use of aviation systems with unmanned aerial vehicles (UAVs) of various classes and special purposes has gained particular relevance and practical importance in the interests of both special customers and civilians. Modern UAVs are used both individually and as part of a group, they can carry several target loads on board simultaneously, they are built on various physical principles: a multifunctional optoelectronic system, a digital aerial system, an airborne radar station, a radio and electronic reconnaissance system, and a system communications for transmitting data from target loads (sensors) to a mobile device (for example, a tablet) to a remote subscriber, etc. However, the question of determining the effectiveness of solving both individual UAV targets and finding an integrated assessment of the effectiveness of using aviation complexes with UAVs when solving a set of targets (sequentially or sequentially-in parallel in time) taking into account their priority and a number of other factors. This article structurally consists of three parts. In the first part, we can observe a scientific and methodological approach to determining the effectiveness of solving particular communication targets and remote monitoring by a complex with UAVs according to the probability of their solution is developed. In the framework of this approach, a mathematical apparatus has been developed for the functional depend-ence of the probabilities of solving particular target problems with the design parameters of target loads as part of the UAV, taking into account the peculiarities of its functioning and under the conditions of existing limitations and assumptions. The scientific and methodological approach allows already at the stage of the formation of the tactical and technical task for the complex with UAVs to obtain, using the calculation method, quantitative estimates of the probabilities of solving particular targets taking into account the technical backlog of industrial enterprises for key components of the complex (target loads, communications equipment complex, etc.). The methodological apparatus developed in the article is universal and invariant with respect to input parameters, i.e., the number of tasks to be solved, the stages of operation of the complex with UAVs, and can be easily adapted to new conditions of use. It should be noted that the result of the article is the methodological apparatus for finding exactly the integral estimate. Finding performance assessments for the group use of UAVs, as well as taking into account possible countermeasures, is beyond the scope of this article and is a direction of further research on this topic.

Bearing Performance Limits With Grease Lubrication

2005 ◽  
Author(s):  
P. M. Cann ◽  
A. A. Lubrecht
Keyword(s):  
Surface Damage ◽  
Design Parameters ◽  
Performance Limits ◽  
Grease Lubrication ◽  
Lubricated Contacts ◽  
System A ◽  
Operating Limits ◽  
Bearing Design ◽  
Cage Effects ◽  
Efficient Mechanisms

This paper has examined the influence of bearing design and operation in controlling lubricant supply to the contact zone. Grease lubricated contacts are liable to starvation and as a result the film thickness is reduced, this can result in surface damage or premature bearing failure. It is of obvious importance to know when starvation occurs and the effect of grease type, bearing design and operation on lubrication replenishment. The aim therefore is to develop a starvation parameter capable of predicting the operating limits for a particular bearing/grease system. A number of bearing design parameters are examined in the paper, these include cage design, ball spin and bearing size. Ball spin and cage effects can be efficient mechanisms for maintaining the lubricant supply to the track. Increased bearing size, line contact geometries and high load result in reduced lubricant replenishment of the contact. Using this analysis it will be possible to establish operating limits for families of bearings.

Man, Institutions and Bioeconomics

2003 ◽  
Vol 14 (4) ◽  
pp. 339-355
Author(s):  
Javier Alfonso Gil
Keyword(s):  
Methodological Approach ◽  
Natural Habitat ◽  
Social Technology ◽  
Activity System ◽  
Material Technology ◽  
Political Market ◽  
System A ◽  
Biological Capacity ◽  
Growth Of Knowledge ◽  
The One

Because bioeconomics is born of the interaction between the biological activity system and its socio-economic activity system, a holistic methodological approach is essential to study the relations between them. However, it must search for increasing levels of reductionism within each discipline to delve into the ultimate nature of each one of the intervening forces, whether economic or biological. This paper explores the economic forces. Through the biological capacity to comprehend, man and by extension, society, accumulates knowledge, the fulcrum from which he is able to dominate over his natural habitat. From this ‘point d’appui’, man builds two basic tools to assist him in achieving the goal of bettering his social condition. On the one hand, he creates institutions that allow him to “live with others” and, on the other, he develops technology that helps him to “live better with others”. Institutions, also referred to as ‘social technology’, tend toward stability over time while technology or ‘material technology’, tends toward instability, which would suggest that, normally, the mechanics of change will originate in material technology and, from there, progress to social technology by way of the political market. The level of progress and development attained depends on the quantity and rate of growth of knowledge applied by a society. In the process, man and his collectivity are forced to adopt new views of their environment through new shared mental models. The concurrence of equipment and political market will ultimately become the prime mover of institutional and economic change as well as change in mentality. Both technologies must keep on an adaptive course of stable evolution since discrepancies arising between them can cause tension between the various social groups. Adequate management of technological shock is essential to avoid extreme situations of social conflict. Herein lie the most important political decisions that a government must confront over the long term.

scholarly journals On the Security of LEO Satellite Communication Systems: Vulnerabilities, Countermeasures, and Future Trends

2022 ◽  
Author(s):  
Pingyue Yue ◽  
Jianping An ◽  
Jiankang Zhang ◽  
Gaofeng Pan ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Satellite Communication ◽  
Future Trends ◽  
Comprehensive Review ◽  
Satellite Communication System ◽  
Development Status ◽  
System A ◽  
Leo Satellite

<div>In view of the development status of the security of LEO satellite communication system, a comprehensive review, induction, and summary is carried out.<br></div>

scholarly journals The use of educational platforms as teaching resource in mathematics

2018 ◽  
Vol 8 (1) ◽  
pp. 63 ◽  
Author(s):  
Marcela Gómez-Zermeño ◽  
Héctor Franco-Gutiérrez
Keyword(s):  
Methodological Approach ◽  
Group Analysis ◽  
School Level ◽  
Dropping Out ◽  
High School Level ◽  
Academic Challenge ◽  
Technological Tool ◽  
The Subject ◽  
Upper Level ◽  
Math Class

Dropping out from the school system at High School level has been a problem for several years; high levels of mathematics’ failing have been a recurring situation. This paper discusses how academic virtual counseling might be a tool to help students in math class. The methodological approach is based in the non-experimental, longitudinal model evolution and in the designs of evolutionary group analysis, we stated the possibility to generalize the results of the use of technological resources in the teaching of mathematics in order to find out if it is possible to improve the levels of students at a school in upper level education. According to this research, the use of educational platforms as a resource for the subject of mathematics represents not only a technological tool for teachers but also offers students the opportunity to view this subject as an academic challenge to overcome

Airflow Uniformity Through Perforated Tiles in a Raised-Floor Data Center

2005 ◽  
Author(s):  
James W. VanGilder ◽  
Roger R. Schmidt
Keyword(s):  
Data Center ◽  
Cooling System ◽  
Design Parameters ◽  
Airflow Rate ◽  
Simple Estimate ◽  
Cfd Models ◽  
System A ◽  
Data Center Cooling ◽  
Floor Plans ◽  
The Impact

The maximum equipment power density (e.g. in power/rack or power/area) that may be deployed in a typical raised-floor data center is limited by perforated tile airflow. In the design of a data center cooling system, a simple estimate of mean airflow per perforated tile is typically made based on the number of CRAC’s and number of perforated tiles (and possibly a leakage airflow estimate). However, in practice, many perforated tiles may deliver substantially more or less than the mean, resulting in, at best, inefficiencies and, at worst, equipment failure due to inadequate cooling. Consequently, the data center designer needs to estimate the magnitude of variations in perforated tile airflow prior to construction or renovation. In this paper, over 240 CFD models are analyzed to determine the impact of data-center design parameters on perforated tile airflow uniformity. The CFD models are based on actual data center floor plans and the CFD model is verified by comparison to experimental test data. Perforated tile type and the presence of plenum obstructions have the greatest potential influence on airflow uniformity. Floor plan, plenum depth, and airflow leakage rate have modest effect on uniformity and total airflow rate (or average plenum pressure) has virtually no effect. Good uniformity may be realized by using more restrictive (e.g. 25%-open) perforated tiles, minimizing obstructions and leakage airflow, using deeper plenums, and using rectangular floor plans with standard hot aisle/cold aisle arrangements.

scholarly journals Written assignments in distance learning and communication with learners as part of the role of the lecturer in the distant education

2017 ◽  
Vol 8 (1) ◽  
pp. 1420-1425
Author(s):  
ANDREAS KARAOULANIS ◽  
VASILIKI KOUKOUSOURI
Keyword(s):  
Distance Learning ◽  
Literature Review ◽  
Educational System ◽  
Methodological Approach ◽  
System A ◽  
Modern Learning ◽  
Research Questions ◽  
Distant Education ◽  
Written Assignments

In this paper the authors tried to underline the importance of distance learning as a means of distant education in the contemporary educational system. A literature review which explains why such a survey is very important in terms of this kind of modern learning was implemented. A short revision of some very important past surveys around the topic of distance learning was carried out, especially in terms of the research questions and the methodological approach that past researchers used in order to dig deeper into the topic. Finally, the results of such empirical researches were analyzed and some critical thoughts of the authors are presented.

scholarly journals Modelling of an Adsorption Heat Storage System and Study of Operating and Design Conditions

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1885
Author(s):  
Sónia Ferreira ◽  
Sabine Sochard ◽  
Sylvain Serra ◽  
Frederic Marias ◽  
Jean-Michel Reneaume
Keyword(s):  
Heat Supply ◽  
Heat Storage ◽  
Physical Adsorption ◽  
Storage System ◽  
Mass Conservation ◽  
Pilot Scale ◽  
Design Parameters ◽  
Fluid Temperature ◽  
Simplified Approach ◽  
System A

An open system based on physical adsorption phenomena with humid air and zeolite 13X is herein discussed for residential heat storage purposes. A model has been developed to describe the conservation of mass and heat in the system. A simplified approach of a complete model describing both mass conservation in the macroporous and microporous domains is used based on the linear driving force (LDF) model. Local mass and heat transfer properties have been used. To describe the equilibrium, the Aranovich–Donohue isotherm model is selected. As an example, the developed model is compared and fitted to experimental data from a pilot scale system. A parametric study on operating and design parameters is given to understand their effect on the amount and/or duration of heat supply, concentration, and temperature profiles. The studied parameters are the inlet adsorbate concentration, fluid temperature, and velocity, as well as particle and zeolite crystal sizes. This analysis shows that an identification of values for the set of parameters tested can possibly suit the energy needs for a case study of domestic heat supply. Future work will focus on the optimization of these parameters.

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