THE MAIN PARAMETERS OF THE STRENGTH CALCULATION OF NOVIKOV GEARING WITH STANDARD BASIC RACK PROFILE

2021 ◽  
pp. 3-11
Author(s):  
V. I. Korotkin ◽  
E. M. Kolosova
Keyword(s):  
Contact Area ◽  
General Purpose ◽  
Machine Building ◽  
Problem Definition ◽  
Strength Calculation ◽  
Spatial Problem ◽  
Basic Parameters ◽  
Definition Of ◽  
Two Stages ◽  
Domestic Machine

The article shows the expediency of using Novikov gearing with standard basic rack profile and with hardened teeth for general purpose gearboxes, also with thermally improved teeth for special purpose gearboxes. It sets out the principled approach for solving the problem definition of basic parameters of the strength calculation of these gears, consisting of two stages: a) definitions of both basic bending, contact stresses and tooth rigidity, and phase taking into account the coefficients of influence of the gear face; b) modeling the process of real multipoint engagement with finding the criterial stress in dangerous sections of the teeth, which determine the load-bearing capacity and service life of the gearbox. Implementing this approach, we obtained generalizing results of solving a spatial problem of the stress-strain state of teeth at any position of the contact area along their length and the way of obtaining partial efforts at the contact area and criterion stresses is indicated. The dependencies, convenient for embedding in the developed computing programs, tables, approximating the power polynomials for determining the basic parameters of the contact were obtained. The completed studies are supposed to be issued in the form allows to offer the method of strength calculation of Novikov gearing with standard basic rack profile domestic machine-building enterprises, producing drives for general engineering and special purpose.

ALTERNATIVE COEFFICIENT OF CONCORDANCE IN CASE OF CONNECTED RANKS

2021 ◽  
pp. 40-45
Author(s):  
Ю.В. Лубенец
Keyword(s):  
Expert Opinion ◽  
Special Kind ◽  
Statistical Characteristics ◽  
Expert Survey ◽  
Complete Consistency ◽  
Expert Opinions ◽  
Coefficient Of Concordance ◽  
Definition Of ◽  
Two Stages ◽  
Good Agreement

Рассматривается оценка согласованности мнений экспертов при проведении экспертного опроса. Наиболее часто в качестве такой оценки применяется коэффициент конкордации Кендалла. Однако этот коэффициент не может в полной мере применяться для установления хорошей согласованности мнений экспертов, поскольку он показывает только отклонение от случаев полной несогласованности. Для устранения данного недостатка может рассматриваться альтернативный коэффициент конкордации, оценивающий близость сумм рангов альтернатив к случаю полной согласованности. Здесь дается определение этого коэффициента при наличии связанных рангов. Сложность определения заключается в том, что в этом случае наблюдается несколько случаев полной согласованности с различными суммами рангов. Определение альтернативного коэффициента конкордации при наличии связанных рангов проводится в два этапа. Сначала вводится его определение для упорядоченных таблиц специального вида и показывается его совпадение с коэффициентом конкордации Кендалла в этом случае. После дается определение альтернативного коэффициента конкордации в общем случае и показывается более простая формула его вычисления. Далее приводятся некоторые примеры сравнений значений рассматриваемых коэффициентов конкордации, их статистических характеристик и гистограмм The article considers evaluation of expert opinion consistency when conducting an expert survey. The most commonly used score is Kendall's coefficient of concordance. However, this coefficient cannot be fully applied to establish good agreement of expert opinions, as it only shows deviations from cases of complete inconsistency. To eliminate this drawback, an alternative concordance coefficient can be considered, which estimates the proximity of the sums of the ranks of the alternatives to the case of complete consistency. The article gives the definition of this coefficient in the presence of connected ranks. The difficulty of this definition lies in the fact that in this case there are several cases of complete consistency with different sums of ranks. Definition of the alternative coefficient of concordance in the presence of tied ranks is carried out in two stages. First, its definition for ordered tables of a special kind is introduced and its coincidence with Kendall's coefficient of concordance in this case is shown. After that, the definition of the alternative coefficient of concordance in the general case is given and a simpler formula for its calculation is shown. Below are some examples of comparisons of the values of the considered concordance coefficients, their statistical characteristics, and histograms

scholarly journals The definition of basic parameters of the set of small-sized equipment for preparation of dry mortar for various applications

2017 ◽  
Vol 116 ◽  
pp. 01004
Author(s):  
Inga Emelyanova ◽  
Vladimir Blazhko ◽  
Svetlana Dansheva ◽  
Natalia Shyshko
Keyword(s):  
Basic Parameters ◽  
Definition Of

scholarly journals Numerical Simulation of Turbulence Flows in Shear Layer

2014 ◽  
Vol 59 (3) ◽  
pp. 1155-1158
Author(s):  
S.V. Fortova
Keyword(s):  
Turbulent Flows ◽  
Shear Layers ◽  
Development Stage ◽  
Inertial Range ◽  
Problem Definition ◽  
Spatial Problem ◽  
Hydrodynamic Instabilities ◽  
Onset Of Turbulence ◽  
Flow Stage ◽  
Vortex Cascade

Abstract For various problems of continuum mechanics described by the equations of hyperbolic type, the comparative analysis of scenarios of development of turbulent flows in shear layers is carried out. It is shown that the development of the hydrodynamic instabilities leads to a vortex cascade that corresponds to the development stage of the vortices in the energy and the inertial range during the transition to the turbulent flow stage. It is proved that for onset of turbulence the spatial problem definition is basic. At the developed stage of turbulence the spectral analysis of kinetic energy is carried out and the Kolmogorov “-5/3” power law is confirmed.

scholarly journals THEORETICAL FUNDAMENTALS OF ESTIMATABILITY ASSESSMENT OF TRAIN SITUATION SIGNS FOR WORK OF INTELLECTUAL LOCOMOTIVE CONTROL SYSTEMS

2021 ◽  
Vol 1 (38) ◽  
pp. 223-231
Author(s):  
O. Gorobсhenko
Keyword(s):  
Control Systems ◽  
Random Search ◽  
Information Value ◽  
Train Control ◽  
Relative Value ◽  
Basic Parameters ◽  
Control Decision ◽  
Definition Of

The article is devoted to the problem of implementation of intelligent control systems in transport. An important task is to assess the information parameters of the control systems. In the existing works the question of definition of one of the basic parameters of functioning of locomotive control systems - information value of separate signs of a train situation is not considered. This does not make it possible to determine the order of signal processing at the input and assess their contribution to the adoption of a control decision. Moreover, informativeness is a relative value, which is expressed in the different information value of a particular feature for the classification of different train situations. Also, the informativeness of the feature may depend on the type of decisive rules in the classification procedure. The quality of recognition of a train situation in which the locomotive crew is, depends on the quality of the features used by the classification system. The decisive criterion for the informativeness of the features in the problem of pattern recognition is the magnitude of losses from errors. To determine the range of the most informative features of train situations, the method of random search with adaptation was used. The results of the work make it possible to optimize the operation of automated and intelligent train control systems by reducing the amount of calculations and simplifying their algorithm.

scholarly journals The Concept of Economic Sustainability of Enterprise and Its Quantitative Assessment

2020 ◽  
Vol 11 (514) ◽  
pp. 220-230
Author(s):  
O. M. Iastremska ◽  
◽  
O. О. Iastremska ◽  
Keyword(s):  
Quantitative Assessment ◽  
Machine Building ◽  
Economic Sustainability ◽  
Marketing Social ◽  
Methodical Approach ◽  
Factors Of Influence ◽  
Social Environmental ◽  
Main Components ◽  
Definition Of ◽  
Relevant Factors

The article is concerned with the issues of determining and evaluating the economic sustainability of enterprise. The publication analyzes the views of scholars on the definition of «economic sustainability of enterprise». A closer definition of this concept is proposed, according to which under the economic sustainability of enterprise it is advisable to understand its complex ability to respond to and withstand the influence of negative relevant factors of the external and internal environment, while maintaining its internal structure, dynamics of operation, which contributes to the achievement of the main goals of functioning and development of enterprises. The main components of economic sustainability of enterprise are allocated, including: financial, industrial, personnel, organizational, marketing, social, environmental, investment, innovation. The main stages of the process of ensuring economic sustainability of enterprise are proposed, the basis of implementing which is the principles of unity – interconnectedness and subordination of all components of sustainability; complexity, which involves taking into account relevant factors of influence; continuity – implementation of the regulatory process on the basis of permanence and sustainability; adequacy, i.e. compliance of the system with patterns of enterprise development. The proposed components and stages of ensuring and determining the economic sustainability of enterprise are used as the basis of the developed methodical approach concerning its quantitative assessment, which is built up using methods of multidimensional factor, cluster analysis, additive convolution method for calculating the integral indicator of economic sustainability of enterprises. The developed methodical approach was tested on the statistical data of nine machine-building enterprises of Kharkiv region, which proved its applied value and possibility of further use.

scholarly journals Socio-economic Determinants of Adolescent Health in Russia

2018 ◽  
Vol 2 (3) ◽  
pp. 70-113
Author(s):  
P. Gazizullina
Keyword(s):  
Adolescent Health ◽  
Structured Interviews ◽  
Economic Determinants ◽  
Promotion Policy ◽  
The Republic ◽  
Definition Of ◽  
Two Stages ◽  
Public Health Promotion ◽  
First Time ◽  
Quantitative And Qualitative Methods

The article presents the results of a comprehensive study of the socio-economic determinants of the health of Russian adolescents, performed using quantitative and qualitative methods. The quantitative analysis was carried out on the basis of the data of the Russian Monitoring of the Economic Situation and Health conducted by the Higher School of Economics for 2010-2016 (19th- 25th waves) using the logistic regression apparatus. Qualitative data are obtained by conducting 39 semi-structured interviews with adolescents aged 14-17 living in the Republic of Udmurtia and the Moscow Region in two stages: in 2010 and 2013. Within the framework of the study, the complex of socio-cultural determinants of health is separately singled out for the first time and its significance is shown for the health of Russian teenagers. The definition of the most significant socio-economic determinants of adolescent health enabled developing a series of recommendations in the area of public health promotion policy.

scholarly journals SBML2Modelica: integrating biochemical models within open-standard simulation ecosystems

2019 ◽  
Vol 36 (7) ◽  
pp. 2165-2172 ◽  
Author(s):  
F Maggioli ◽  
T Mancini ◽  
E Tronci
Keyword(s):  
State Of The Art ◽  
General Purpose ◽  
Heterogeneous Model ◽  
Simulation Languages ◽  
Experimental Campaign ◽  
Heterogeneous Models ◽  
Open Standard ◽  
Level 3 ◽  
Model Networks ◽  
Definition Of

Abstract Motivation SBML is the most widespread language for the definition of biochemical models. Although dozens of SBML simulators are available, there is a general lack of support to the integration of SBML models within open-standard general-purpose simulation ecosystems. This hinders co-simulation and integration of SBML models within larger model networks, in order to, e.g. enable in silico clinical trials of drugs, pharmacological protocols, or engineering artefacts such as biomedical devices against Virtual Physiological Human models. Modelica is one of the most popular existing open-standard general-purpose simulation languages, supported by many simulators. Modelica models are especially suited for the definition of complex networks of heterogeneous models from virtually all application domains. Models written in Modelica (and in 100+ other languages) can be readily exported into black-box Functional Mock-Up Units (FMUs), and seamlessly co-simulated and integrated into larger model networks within open-standard language-independent simulation ecosystems. Results In order to enable SBML model integration within heterogeneous model networks, we present SBML2Modelica, a software system translating SBML models into well-structured, user-intelligible, easily modifiable Modelica models. SBML2Modelica is SBML Level 3 Version 2—compliant and succeeds on 96.47% of the SBML Test Suite Core (with a few rare, intricate and easily avoidable combinations of constructs unsupported and cleanly signalled to the user). Our experimental campaign on 613 models from the BioModels database (with up to 5438 variables) shows that the major open-source (general-purpose) Modelica and FMU simulators achieve performance comparable to state-of-the-art specialized SBML simulators. Availability and implementation SBML2Modelica is written in Java and is freely available for non-commercial use at https://bitbucket.org/mclab/sbml2modelica.

scholarly journals Calculation of composite elements of slabs in buildings, structures and fragments of spans of bridges

2018 ◽  
Vol 230 ◽  
pp. 02007 ◽  
Author(s):  
Stanislav Fomin ◽  
Yuriy Izbash ◽  
Serhii Butenko ◽  
Maryna Iakymenko ◽  
Karina Spirande
Keyword(s):  
Bearing Capacity ◽  
High Temperatures ◽  
Composite Structures ◽  
Strain Ratio ◽  
Strain Diagram ◽  
Stress Strain ◽  
Maximum Deformation ◽  
Definition Of ◽  
Two Stages ◽  
The Mathematical Model

The calculation consists of two stages. The first one begins with the definition of their class, bearing capacity at temperature of 20 °C, according to EN 1992-1-1. At the second stage, the calculation at high temperatures shall be carried out in accordance with Eurocode 4 part 1-2. Comparison of the “stress-strain” diagram of concrete of class 30 under compression and temperature of 20 °C in two formulas showed their difference. That is, the designers do not have the opportunity to continue the calculation of diagrams at different heating temperatures. There was a need to improve the mathematical model of the “stress-strain” ratio of concrete high temperatures, clarification of the criteria of the bearing capacity of concrete in calculation of the fire resistance of composite structures in EN 1994-1-2:2005. In this paper, the method of determination of εcu1,θ developed has allowed, based on the energy approach, to formulate the corrected dependence of the limit deformation on temperature, dependence of the maximum deformation on temperature, and the value of the parameters of the “stress-strain” diagram. According to these data, using the formulas of the first stage, the “stress-strain” diagrams of the concrete of class 30 are calculated at the compression and heating according to EN 1992-1-2:2004.

A Reverse Glue Approach to Automated Construction of Multi-Piece Molds

2003 ◽  
Author(s):  
Yong Chen ◽  
David W. Rosen
Keyword(s):  
Design Process ◽  
Problem Definition ◽  
Mold Cavity ◽  
Mold Design ◽  
Difficult Time ◽  
Construction Step ◽  
Efficiency And Effectiveness ◽  
Definition Of ◽  
Face Generation ◽  
Construction Algorithms

Mold design can be a difficult, time-consuming process. Determining how to split a mold cavity into multiple mold pieces (e.g., core, cavity) manually can be a tedious process. This paper focuses on the mold construction step of the automated mold design process. By investigating glue operations and its relations with parting faces, an approach based on reverse glue operation is presented. The key of the reverse glue operation is to generate parting faces. A problem definition of parting face generation for a region is provided. Correspondingly, three face generating criteria are identified. Based on the parting lines of a region, our algorithms to generate the parting faces are presented. Our mold construction algorithms for two-piece molds and multi-piece molds are also presented with brief discussions. Some industrial examples are provided which illustrate the efficiency and effectiveness of our approach. We tested our mold designs by fabricating stereolithography mold inserts (a rapid tooling method) and molding parts.

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