scholarly journals ПІДБІР КІЛЬКОСТІ ЗУБЦІВ ПЛАНЕТАРНИХ МЕХАНІЗМІВ СХЕМ AA, II, AI, IA, І ЗА ДОПОМОГОЮ ПРОГРАМНОГО ЗАБЕЗПЕЧЕННЯ

2021 ◽  
pp. 87-100
Author(s):  
В. Н. Данилов
Keyword(s):  
Gear Ratio ◽  
Maximum Efficiency ◽  
Maximum Speed ◽  
System Of Equations ◽  
Planetary Gears ◽  
Number Of Teeth ◽  
The Given ◽  
Number Of Iterations ◽  
Selection Of ◽  
Planetary Mechanism

Most of the methods for selecting the numbers of teeth of planetary mechanisms are based on general equations that take into account three main conditions for their existence: 1) ensuring a given gear ratio, 2) the condition of alignment, 3) the condition of assembly. The rest of the conditions are not included in the system of equations to be solved and are checked additionally. However, this approach has a number of disadvantages associated with the discreteness of the general equations depending on several parameters. Therefore, a method is proposed for selecting the number of teeth using equations obtained only when taking into account two mandatory conditions for the existence of planetary mechanisms: 1) ensuring a given gear ratio, 2) the condition of alignment. Equations for fitting by this method are presented. The remaining conditions for the existence of planetary gears are checked separately and as a result, unsuitable solutions are excluded. This approach ensures the selection of all existing solutions in a given range of teeth numbers with a relatively small number of iterations, but it is rational only when used on a computer. In this regard, the corresponding software has been written - the Planmex.exe program. A description of this program is given, which allows you to select the number of teeth of the wheels of the proposed schemes of planetary gears with a whole and fractional gear ratio, different modules of wheels on a double satellite, a different number of satellites in a given range of numbers of teeth, depending on the selected driving link. Three variants of optimization of the obtained results of selection of the number of teeth are proposed: 1) minimum mass, 2) maximum speed, 3) maximum efficiency. Coefficients are introduced to compare the results within each optimization option and equations are proposed to determine them. An example of the selection of the number of teeth for different modules of gears on a double satellite of the planetary mechanism of the AI scheme by the proposed method using the Planmex.exe program is given. The optimization of the obtained results is made according to three criteria, taking into account the region of existence of the given scheme.

scholarly journals On some properties of determinants with complex elements and their practical application

2021 ◽  
pp. 67-77
Author(s):  
Mykhailo Fys ◽  
Roman Kvit ◽  
Tetyana Salo
Keyword(s):  
Closed Form ◽  
Imaginary Part ◽  
Complex Numbers ◽  
System Of Equations ◽  
Order Complex ◽  
Symmetric Polynomials ◽  
Practical Application ◽  
The Real ◽  
The Given ◽  
Selection Of

The formulas presented in this paper make it possible to select the real and imaginary part of the determinant value of the n -th order complex quantity, greatly simplifying the process of its deployment. Moreover, its module is given by the determinant of the 2n -th order, the elements of which are the real and imaginary parts of complex numbers. This makes it possible to analyze analytically the process described using determinants with complex numbers. The real and imaginary parts are also determined by the sum of determinants already with n rows and columns, the elements of which make up complex elements. The terms of this sum are solutions of a system of equations represented in closed form using symmetric polynomials, the arguments of which are its coefficients. Part of this combination is expressed by two determinants of the n -th order, the elements of which are the sum and difference of the real and imaginary parts of the elements. This significantly reduces the number of arithmetic operations during the deployment of a complex determinant and the selection of its real and imaginary parts. The given numerical example confirms the feasibility of this approach.

Study on the Modes of Operation of a Multi-Machine Installations with Mechanical Reduction

2019 ◽  
pp. 12-22
Author(s):  
A. M. Oleynikov ◽  
L. N. Kanov
Keyword(s):  
Mathematical Description ◽  
Reactive Power ◽  
Maximum Efficiency ◽  
Wind Flow ◽  
System Of Equations ◽  
Mechanical Equilibrium ◽  
Synchronous Generators ◽  
Electromagnetic Excitation ◽  
Number Of Generators ◽  
Wide Range

The paper gives the description of the original wind electrical installation with mechanical reduction in which the output of vertical axis wind turbine with rather low rotation speed over multiplicator is distributed to a certain number of generators. The number of acting generators is determined by the output of actual operating wind stream at each moment. According to this constructive scheme, it is possible to provide effective and with maximum efficiency installation work in a wide range of wind speeds and under any schedule issued to the consumer of electricity. As there are no any experience in using such complexes, mathematical description of its main elements is given, namely windwheels, generators with electromagnetic excitation of magnetic electrical type, then their interaction with windwheel, and also the results of mathematical modeling of work system regimes under using the offered system of equations. The basis for the mathematical description of the main elements of the installation – synchronous generators – are the system of equations of electrical and mechanical equilibrium in relative units in rotating coordinates without considering saturation of the magnetic circuit. The equation of mechanical equilibrium systems includes torque and brake windwheel electromagnetic moments of generators with taking into account the reduction coefficients and friction. In addition, we specify the alternator rotor dynamics resulting from continuous torque of windwheel fluctuations under the influence of unsteady wind flow and wind speed serving as the original variable is modeled by a set of sinusoids. Model simplification is achieved by equivalization of similar generators and by disregarding these transitions with a small time constant. Calculation the installation with synchronous generators of two types of small and medium capacity taking into account the operational factors allowed us to demonstrate the logic of interactions in the main elements of the reported complex in the process of converting wind flow into the generated active and reactive power. We have shown the possibility of stable system work under changeable wind stream condition by regulating of the plant blade angle and with simultaneous varying of generator number of different types. All these are in great interest for project organizations and power producers.

Application of the turbidity ratio method in the spherical particle size determination in the range m ∈ and α ∈

1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann
Keyword(s):  
Refractive Index ◽  
Spherical Particle ◽  
Ratio Method ◽  
Refractive Indices ◽  
Relative Refractive Index ◽  
Particle Size Determination ◽  
The Individual ◽  
The Given ◽  
Turbidity Ratio ◽  
Selection Of

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.

scholarly journals THE STYLISTIC FUNCTIONING OF SCRIPTURAL ALLUSIONS IN AN EARLY MODERN ENGLISH PLAY “JOHAN BAPTYSTES PREACHYNGE” BY J. BALE

2020 ◽  
Vol 30 (6) ◽  
pp. 1001-1007
Author(s):  
A.A. Khavronich
Keyword(s):  
Early Modern ◽  
Early Modern English ◽  
Semantic Expansion ◽  
Early English ◽  
The Given ◽  
Selection Of

The given article analyzes the peculiarities of the stylistic functioning of allusions to the Holy Scripture within one religious play belonging to the modern early English period, namely “Johan Baptystes Preachynge” produced by a dramatist J. Bale. The analysis is performed from the standpoint of linguopoetics. We consider stylistic features via the correlation of form and meaning, dissection of the conceptual component, juxtaposition with medieval plays representing adaptations of the same scriptural plot. Within the framework of this analysis we identify and assess elements performing the function of impact incorporated into the scriptural allusions and estimate their role in the selection of other lexical units, construction of extended metaphors, syntactic shaping of particular fragments of the play. We draw a conclusion that via the extension of scriptural metaphorical complexes the author brings about a meaningful focus shift to ensure a protestant reinterpretation of the included biblical theses. A substantial share of stylistically marked elements undergoes semantic expansion and develops adherent connotations since they relate to the pivotal elements of the allusions.

scholarly journals Selection of the variant solution of forest road alignment conceptual design using multicriteria optimisation

2009 ◽  
pp. 165-176 ◽  
Author(s):  
Bogdan Stefanovic ◽  
Ivan Bjelanovic
Keyword(s):  
Conceptual Design ◽  
Multicriteria Optimization ◽  
Linear Distribution ◽  
Forest Road ◽  
Multicriteria Optimisation ◽  
Technical Production ◽  
The Given ◽  
Selection Of ◽  
Design Construction ◽  
Building Parameters

One of the three studied variant solutions of forest road conceptual design was selected based on the linear distribution of criteria, as the method of multicriteria optimization. The selection was performed with 25 parameters classified as economic, technical, production and social criteria. The parameters of technical criteria were grouped into design, construction and building parameters. Based on calculated nominal values of parameters by the given criteria, their ranking, comparison, point rating and scoring, the selected most favorable solution was variant 1.

scholarly journals Vulnerability analysis and method of selection of communication protocols for information transfer in Internet of Things systems

2021 ◽  
pp. 133-149
Author(s):  
Maryna Kolisnyk
Keyword(s):  
Internet Of Things ◽  
Initial Data ◽  
Information Transfer ◽  
System Analysis ◽  
Communication Protocols ◽  
Critical Systems ◽  
Smart Objects ◽  
Corporate System ◽  
The Given ◽  
Selection Of

The subject of study in the paper is the analysis of technologies, architectures, vulnerabilities and cyberattacks, communication patterns of smart objects, messaging models, and Internet of Things (IoT) / Web of Things (WoT) protocols for solving applied problems of critical and non-critical systems. The goal is to develop a method for selecting messaging models and application-level protocols in non-critical and critical multi-level IoT/WoT systems, provided that the type of access to intelligent objects is initially determined by the initial data, as well as analysis of vulnerabilities and attacks using these protocols. Objectives: to formalize the procedure for choosing communication protocols for IoT/WoT systems; analyze possible vulnerabilities of communication protocols; develop a method for selecting communication protocols for given initial data, depending on the selected type of communication template for smart objects; check practically the proposed method. The methods of research are methods of system analysis. The following results were obtained. The analysis of the features of communication protocols is conducted by comparing the main interrelated characteristics of IoT/WoT, the results of which are presented in the form of a table. A method has been developed for selecting communication protocols, depending on the selected type of communication template. The analysis of possible vulnerabilities of communication protocols and possible attacks using these protocols is conducted. The author has tested the method using the example of a corporate system (Smart House) based on the WoT concept. Findings. The scientific novelty of the results obtained is as follows: the analysis conducted in the paper shows that currently there is no unified approach to the choice of a messaging model and application-level protocols for building IoT/WoT, depending on the selected type of communication template for smart objects. The method for selecting communication protocols for the given conditions (for each IoT system its interaction pattern will correspond, depending on which components interact with each other), improved by the authors of the paper, makes it possible to simplify the task of using separate protocols for given IoT systems, considering vulnerabilities of protocols.

scholarly journals The Evaluation of Agricultural Land Use Sustainability in the Post-Socialist Camp Countries: Methodological and Practical Aspects

2021 ◽  
Vol 13 (2) ◽  
pp. 59-78
Author(s):  
Olena Kotykova ◽  
Mykola Babych
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Sustainable Use ◽  
Correct Selection ◽  
Agricultural Land Use ◽  
Current State ◽  
Definition Of ◽  
The Given ◽  
Selection Of ◽  
Integral Indicator

An effective implementation of the sustainable use of agricultural land program is impossible without reliable results of the current state of the problem. In this sense, the correct selection of indicators and methods for determining the level of stability is important. The authors proposes the definition of the agricultural land use sustainability integral indicator based on three methodological approaches: the construction of the indicators system, each of them reflects some aspects of the land use sustainability at the macro level (according to the specific issues); the construction of the integral indicator for comparing the countries’ land use sustainability. According to the given methods it has been proved that agricultural land use in the countries of the post-socialist camp has a positive dynamics, but the sustainability indicators for all indicators have not achieved yet. This study was supported in part by the Erasmus SUPPA program – Jean Monnet Associations Application No 611556-EPP-1-2019-1-UA-EPPJMO-SUPPA.

scholarly journals A Generalization of the Blackwell–Ryll-Nardzewski Measurable Selection Theorem

2021 ◽  
Vol 134 (1) ◽  
pp. 35-41
Author(s):  
K.A. Afonin ◽  
◽  
Keyword(s):  
Metric Spaces ◽  
Transition Probability ◽  
Measurable Space ◽  
Measurable Selection ◽  
Selection Theorem ◽  
Borel Set ◽  
Borel Probability ◽  
Borel Mapping ◽  
The Given ◽  
Selection Of

One of the main forms of the measurable selection theorem is connected with the existence of the graph of a measurable mapping in a given measurable set 𝑆 in the product of two measurable spaces 𝑋 and 𝑌 . Such a graph enables one to pick a point in the section 𝑆𝑥 for each 𝑥 in 𝑋 such that the obtained mapping will be measurable. The indicated selection is called a measurable selection of the multi-valued mapping associating to the point 𝑥 the section 𝑆𝑥 , which is a set in 𝑌 . The classical theorem of Blackwell and Ryll-Nardzewski states that a Borel set 𝑆 in the product of two complete separable metric spaces contains the graph of a Borel mapping (hence admits a Borel selection) provided that there is a transition probability on this product with positive measures for all sections of 𝑆 . The main result of this paper gives a generalization to the case where only one of the two spaces is complete separable and the other one is a general measurable space whose points parameterize a family of Borel probability measures on the first space such that the sections of the given set 𝑆 in the product have positive measures.

scholarly journals THE STATIC OPTIMIZATION TASK OF OPTIMAL DESIGN OF NONLINEAR ELECTRONIC SCHEME

2019 ◽  
pp. 109-115
Author(s):  
Didmanidze Ibraim ◽  
Donadze Mikheil
Keyword(s):  
Optimal Design ◽  
Optimality Criteria ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Design Task ◽  
Optimization Task ◽  
Minimum Capacity ◽  
Optimal Values ◽  
The Given ◽  
Selection Of

The article deals with such an important selection of the elements of electronic scheme of the given configuration, when the certain requirements of technical task are satisfied and at the same time the selected optimality criteria reach the extreme value. The gives task has been solved by the method of one-criterion optimization, in particular, the method of center gravity. To formalize the given scheme we have compiled a mathematical model of optimization, which considers the requirements of technical task. The optimal design task of the presented electronic scheme was brought to the task of multi criteria optimization. The computational experiments have been resulted in the Pareto-optimal solutions, from which there was selected a compromise on that corresponds to the minimum capacity, required by the scheme. According to the optimal values of resistors, we have conducted a computerized analysis of the transient process of the given electronic scheme with the help of a computer program Electronics Workbench.

scholarly journals THE GRAVITY MODEL FORMALIZATION FOR THE INTERCITY PASSENGER’S CORRESPONDENCES PARAMETER’S ESTIMATION

2017 ◽  
Vol 16 (5) ◽  
pp. 437-443 ◽  
Author(s):  
C. V. Dolya
Keyword(s):  
Gravity Model ◽  
Transportation System ◽  
Gravity Models ◽  
Gravity Modeling ◽  
Passenger Transport ◽  
Passenger Transportation ◽  
The Given ◽  
Selection Of ◽  
Calibration Coefficients

he paper considers a possibility to apply gravity models for calculation of intercity passenger transport corres- pondences which are implemented with the help of public transport. The Ukraine transportation system has been selected as an object of investigation and this approach extends application possibilities of the obtained results. Calibration coefficients used in calculation of the indicated correspondences are rather important and significant in case of forecasting passenger transport correspondences. Formalization of these factors is necessary for every transportation system if a calculation of pas-senger transport correspondences has been made for it. In this case searching for actual calibration parameters and other coef-ficients as components of gravitational models is a relevant objective of the given paper. Selection of the gravity model va- riant plays rather significant role in solution of this problem. The developed methods for calculation of passenger transport correspondences are proposed for their application in respect of various transport and trip types. The executed research works have made it possible to investigate a process pertaining to providing of services for passenger transportation while using public routes. The obtained characteristics on functioning of the studied system have allowed to assess the possibility for ap-plication of the known methods for calculation of passenger correspondences and analyze the quality of their application. Calibration coefficients have been empirically selected for calculation of the indicated correspondences while using method of gravity modeling. Formalization of previously unexplored parameters of gravity model component provides the possibility to apply the considered approach for calculation of passenger correspondences within the framework of the investigated trans-portion system. This makes it possible to plan and arrange interaction of various transport types and provides new data and knowledge on the studied system.

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