scholarly journals Mathematical model of the interaction of wheeled skidder with skid trail in the rotate mode

2019 ◽  
Author(s):  
Х.Ж. Као ◽  
А.М. Кочнев ◽  
Л.Л. Нгуен
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Research Method ◽  
Not Given ◽  
Damping Properties ◽  
Direct And Inverse Problems ◽  
Damping Characteristics ◽  
Inverse Problems Of Dynamics ◽  
Object Of Study ◽  
Nonlinear Nature

Вопросам взаимодействия колесного трелевочного трактора с пачкой древесины и волоком в режиме поворота уделяется недостаточно внимания. Разработанные математические модели не учитывают такие важные свойства объекта исследования, как упругодемпфирующие характеристики шин в продольном, поперечном направлениях и на скручивание, упруго- демпфирующие свойства механизма складывания и трелюемой пачки древесины, нелинейный характер работы элементов системы и связи их между собой. Цель исследования – разработка математической модели взаимодействия колесного трелевочного трактора с волоком в режиме поворота с учетом упруго- демпфирующих свойств шин, механизма складывания и трелюемой пачки древесины. Метод исследования – математическое моделирование. Исследование полученной системы дифференциальных управлений на ЭВМ дает возможность решить как прямую, так и обратную, задачи динамики. Проведенное исследование подтвердило адекватность разработанной математической модели взаимодействия колесного трелевочного трактора с пачкой древесины и волоком в режиме поворота. Расхождение результатов – 12–16%, что позволяет рекомендовать ее для использования в АСНИ и САПР «Колесный трелевочный трактор». The interaction of the wheeled skidder with a pack of wood and fiber in the mode of rotation is not given enough attention. The developed mathematical models do not take into account such important properties of the object of study as elastic-damping characteristics of tires in the longitudinal, transverse directions and twisting, elastic- damping properties of the mechanism with the laying and the trill packet of wood, the nonlinear nature of the system elements and their relationship to each other, etc. The purpose of this article is to develop a mathematical model of interaction wheel skidder tractor with fiber in the mode of rotation, taking into account the elastic properties of tires, folding mechanism and a trill packet of wood. Research method-mathematical modeling. The study of the obtained system of differential controls on a computer makes it possible to solve both direct and inverse problems of dynamics. Studies have confirmed the adequacy of the developed mathematical model of interaction wheel skidder with a bundle of wood and fiber in the mode of rotation, the discrepancy of results – 12–16%, which allows to recommend it for use in ASNI and CAD «Wheel skidder».

Research on Damping Properties of Seperated and Manually Adjustable Shock Absorber Oriented to Damping Matching

2013 ◽  
Vol 694-697 ◽  
pp. 36-40 ◽  
Author(s):  
Da Feng Song ◽  
Gong Ke Yang ◽  
Chun Xiao Du
Keyword(s):  
Mathematical Model ◽  
Structural Changes ◽  
Shock Absorber ◽  
Structural Parameters ◽  
Characteristic Curve ◽  
Bench Test ◽  
Damping Properties ◽  
Damping Characteristics ◽  
Test Use ◽  
The Mathematical Model

On the basis of the structure characteristics of the seperated manually adjustable damper and its working principles, establish the shock absorber mathematical model, at the same time, get test data and curves of seperated manually adjustable shock absorber damping characteristics by bench test. Use MATLAB to simulate the characteristic curve of the speed of the shock absorber based on the mathematical model. The simulation curves and experimental curves were compared to verify the correctness and accuracy of the model. Further simulation and analysis affect of parts of structural changes on the damping characteristics. In order to provide a theoretical basis to structural parameters designing and vehicle damping matching.

scholarly journals Forecasting secessions though mathematical modeling

2021 ◽  
pp. 57-79
Author(s):  
A. Tokarev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Research Method ◽  
Main Research ◽  
Parent State ◽  
De Facto States

The article outlines and discusses the universal mathematical model created by the author and allowing to predict scenarios for post-Soviet secessions and, more broadly, to forecast secession potentials of any complex subnational regional units. The objects of forecasting are de facto states and different kinds of polities with failed statehood, analyzed through the prism of the “parent state – secession – patron state” triangle. The main research method is quantification of secession factors, which enables a researcher to measure the impacts of objective and subjective conditions on the course and results of secessions through the use of specific variables and indicators. As described in mathematical terms, the model has two extremes: “ideal secession” and “ideal anti-secession”.

scholarly journals METHODOLOGY OF DEVELOPMENT OF MATHEMATICAL MODELS OF INFORMATION PROCESSING SYSTEMS

2021 ◽  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Information System ◽  
Information Processing ◽  
Mathematical Models ◽  
System Approach ◽  
Research Method ◽  
Literary Sources ◽  
History Of ◽  
The Mathematical Model

Modeling as a research method is a powerful cognitive tool throughout the history of human development. The article describes the methodology for the development of mathematical models of information systems, based on materials from various literary sources, author's developments on the system approach, mathematical modeling and programming. The mathematical model of the information system is described and all the characteristics of the IS are given.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

On the displacements of the contours of the optic-electronic space images. Mathematical modeling of displacement

2017 ◽  
Vol 992 (4) ◽  
pp. 32-38 ◽  
Author(s):  
E.G. Voronin
Keyword(s):  
Mathematical Modeling ◽  
Remote Sensing ◽  
Mathematical Model ◽  
Point Of View ◽  
Design Features ◽  
Space Images ◽  
Electronic Imaging ◽  
Measuring Accuracy ◽  
Physical Laws

The article opens a cycle of three consecutive publications dedicated to the phenomenon of the displacement of the same points in overlapping scans obtained adjacent CCD matrices with opto-electronic imagery. This phenomenon was noticed by other authors, but the proposed explanation for the origin of displacements and the resulting estimates are insufficient, and developed their solutions seem controversial from the point of view of recovery of the measuring accuracy of opticalelectronic space images, determined by the physical laws of their formation. In the first article the mathematical modeling of the expected displacements based on the design features of a scanning opto-electronic imaging equipment. It is shown that actual bias cannot be forecast, because they include additional terms, which may be gross, systematic and random values. The proposed algorithm for computing the most probable values of the additional displacement and ways to address some of the systematic components of these displacements in a mathematical model of optical-electronic remote sensing.

Mathematical modeling of fluid movement inside the eyeball during intravitreal injection

2021 ◽  
pp. 106-109
Author(s):  
D.V. Lipatov ◽  
◽  
S.A. Skladchikov ◽  
N.P. Savenkova ◽  
V.V. Novoderezkin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Residence Time ◽  
Complex Structure ◽  
Posterior Vitreous Detachment ◽  
Vitreous Body ◽  
Complete Removal ◽  
Intravitreal Injections ◽  
The World

Background. The avalanche-like growth of intravitreal injections in the world has significantly increased interest in the hemodynamics of the processes that occur in the eye when a drug is injected into the vitreous cavity. Every year, the number of intravitreally used drugs and promising areas in which they can be used is growing. This also applies to the creation of new combined medicines and the development of drugs with a long-term therapeutic effect. Aims. Create mathematical model of eyeball to evaluate the movement of the drug substance in it; to estimate the time of the drug's presence in the eye cavity before its complete removal, to characterize the ways of its removal from the eye cavity; to assess the significance of posterior vitreous detachment during the time when the drug is present in the eye cavity; to evaluate the effect on the hydrodynamics of the depth of drug administration. Results. When the drug is administered closer to the center of the eyeball, its residence time increases in comparison with the parietal administration. With a complete posterior detachment of the vitreous body, the time of finding the drug in the eye is prolonged compared to its absence. The obtained results of mathematical modeling of the movement of the drug administered intravitreally cannot be mechanically transferred to the human eye, due to the more complex structure of the latter. Key words: intravitreal injections, vitreous body, mathematic computing.

MATHEMATICAL MODELING OF CONCRETE STRUCTURE CORROSION IN BIOLOGICALLY AGGRESSIVE ENVIRONMENTS

2021 ◽  
Vol 3 (102) ◽  
pp. 55-67
Author(s):  
VARVARA E. RUMYANTSEVA ◽  
SVETLANA A. LOGINOVA ◽  
NATALIA E. KARTSEVA
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Mass Transfer ◽  
Parabolic Type ◽  
Cement Concrete ◽  
Mass Conductivity ◽  
Kinetics And Dynamics ◽  
Biological Corrosion ◽  
First Time ◽  
Fourth Kind

In the aquatic environment, biocorrosion is an important factor affecting the reliability and durability of concrete structures. The destruction of cement concretes during biological corrosion is determined by the processes of mass transfer. The article presents the development of a calculated mathematical model of liquid corrosion in cement concrete, taking into account the biogenic factor. For the first time, a model of mass transfer in an unbounded two-layer plate is considered in the form of differential equations of parabolic type in partial derivatives with boundary conditions of the second kind at the interface between concrete and liquid and of the fourth kind at the interface between concrete and biofilm. The results of a numerical experiment are presented to study the influence of the coefficients of mass conductivity and mass transfer on the kinetics and dynamics of the process.

Methods of Mathematical Modeling of the Leaching Process of Cobalt-Containing Solutions

2021 ◽  
Vol 316 ◽  
pp. 661-666
Author(s):  
Nataliya V. Mokrova
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Chemical Kinetics ◽  
Group Method ◽  
Data Handling ◽  
Multistage Processes ◽  
Leaching Process ◽  
Proposed Model ◽  
Simulation Results ◽  
The Mathematical Model

Current cobalt processing practices are described. This article discusses the advantages of the group argument accounting method for mathematical modeling of the leaching process of cobalt solutions. Identification of the mathematical model of the cascade of reactors of cobalt-producing is presented. Group method of data handling is allowing: to eliminate the need to calculate quantities of chemical kinetics; to get the opportunity to take into account the results of mixed experiments; to exclude the influence of random interference on the simulation results. The proposed model confirms the capabilities of the group method of data handling for describing multistage processes.

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