scholarly journals A Mathematical Model for Top Nutation Based on Inertial Forces of Distributed Masses

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ryspek Usubamatov ◽  
Albina Omorova

The main property of gyroscopic devices is maintaining the axis of a spinning rotor, a mathematical model formulated on the principle of the change in the angular momentum. This principle is used for mathematical modeling of the motions of a top at known publications. Nevertheless, practical tests of gyroscopic devices do not correspond to this analytical approach. Recent investigations have demonstrated that the origin of gyroscope properties is more complex than that represented in known publications. The applied torque on a gyroscope produces internal torques of the spinning rotor based on the action of the several inertial forces. These forces are the centrifugal, Coriolis, and common inertial forces as well as the change in the angular momentum generated by the mass elements and center-mass of the spinning rotor. The action of these torques manifests itself in the resistance and precession torques of the gyroscopic devices. These inertial torques act simultaneously and interdependently around two axes and represent the fundamental principles of the gyroscope theory. The new inertial torques enable deriving mathematical models for the motions of well-known top that is the simplest form of gyroscopic devices. The novelty of the work is mathematical models for the motions of the top based on action of eight inertial forces acting around its two axes. The obtained mathematical models for the top nutation and self-stabilization are represented in terms of machine dynamics and vibration analysis. The new analytical approach for motions of the well-balanced top and top with eccentricity of the center-mass definitely responds to the practical results.

2019 ◽  
Vol 2 (4) ◽  

The topic of the top motions is not new but the known publications represent wrong mathematical models for its gyroscopic effects. Recent investigations have demonstrated the physics of gyroscopic effects is more complex. On any spinning objects are acting the system of interrelated internal torques generated by their rotating mass elements and center mass. The inertial torque is produced by the centrifugal, common inertial and Coriolis forces, as well as the change in the angular momentum. These inertial torqueses represent the fundamental principle of gyroscope theory. The new inertial torques enables deriving mathematical models for the motions of any rotating objects that were impossible for a long time. The aim of this work is to represent mathematical models for the motions of the well-balanced top on the flat horizontal surface. This work describes the physics of the top motions and closes the problem of many years of discussion. The new analytical approach for the top’s motions definitely responds to the practical results and represents a good example of the educational process.


2021 ◽  
Vol 273 ◽  
pp. 08003
Author(s):  
Arthur Alukhanyan ◽  
Olga Panfilova

This work is devoted to development of economic and mathematical models for selection of the optimum investment solution. Moreover, it states the basis for development of model examples and correction of the model considering the results obtained in the examples. In the work the problem is set for selection of the investment sources and objects, which is limited to the linear programming problem. The controlled variable and basic limitations simulating real credit and monetary relations are distinguished in the provided model. The discounted profit obtained from implementation of the optimum investment portfolio is considered as a target function. The economic and mathematical model presented in the article allows finding the optimum investment solution within the limits of the credit and monetary relations taking place both at the micro- and macroeconomic level.


1983 ◽  
Vol 15 (8-9) ◽  
pp. 197-207 ◽  
Author(s):  
M Lindgren

A dilute synthetic waste water was anaerobica1ly treated in a filter. A mathematical model of the anaerobic filter process was also developed and analyzed. Analysis showed that mathematical models are an efficient tool for system understanding and design.


1997 ◽  
Vol 11 (1) ◽  
pp. 127-132 ◽  
Author(s):  
George H. Dibdin

A set of mathematical equations constitutes a mathematical model if it aims to represent a real system and is based on some theory of that system's operation. On this definition, mathematical models, some very simple, are everywhere in science. A complex system like a biofilm requires modeling by numerical methods and, because of inevitable uncertainties in its theoretical basis, may not be able to make precise predictions. Nevertheless, such models almost always give new insight into the mechanisms involved, and stimulate further investigation. The way in which diffusion coefficients are measured for use in a model, particularly whether they include effects of reversible reaction, is a key element in the modeling. Reasons are given for separating diffusion from reversible reaction effects and dealing with them in a separate subroutine of the model.


2021 ◽  
Vol 22 (4) ◽  
pp. 595-608
Author(s):  
A. Molter ◽  
R. S. Quadros ◽  
M. Rafikov ◽  
D. Buske ◽  
G. A. Gonçalves

The outbreak of COVID-19 has made scientists from all over the world do not measureefforts to understand the dynamics of the disease caused by this coronavirus. Several mathematical models have been proposed to describe the dynamics and make predictions. This work proposes a mathematical model that includes social isolation of susceptible individuals as a strategy of suppression and mitigation of the disease. The Susceptible-Infectious-Isolated-Recovered-Dead (SIQRD) model is proposed to analyze three important issues about the dynamics of the disease taking into account social isolation: when the isolation should begin? How long to keep the isolation? How to get out of this isolation? To get answers, computer simulations are provided and their results discussed. The results obtained show that beginning social isolation on the 10th or 15th days, after confirmation of the 50th case, and with 70% of the population in isolation, seems to be promising, since the infected curve does not grow much until it enters the isolation and remains at a stable level during the isolation. On the other hand an abrupt release of the social isolation will imply a second peak of infected individuals above the first one, which is not desired. Therefore, the release from social isolation should be gradual.


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.


Author(s):  
V.I. Bogdanovich ◽  
◽  
M.G. Giorbelidze ◽  
I.A. Dokukina ◽  
N.V. Surkova ◽  
...  

Developed a mathematical model for determining residual stresses with increasing plasma coatings, taking into account the stresses arising upon cooling of the material from the final temperature to ambient temperature; tension that arises when removing the fastening devices and tension that existed in the substrate before spraying. The developed mathematical models are adapted for the most common cases of fixing the base used in the practice of coating. Experimental studies of residual stresses were carried out, which showed good convergence with the values of residual stresses obtained theoretically.


Author(s):  
Olena LEVCHUK

In the context of globalization processes, the professional activity of future economists is characterized by dynamism, complexity and uncertainty of conditions. Informatization and fundamentalization of knowledge provide relevance to such components of professional competence of the future economist as the ability to think analytically, solve predictive tasks using software products, implement economic and mathematical modeling using modern information systems, apply computer data processing technologies to solve economic problems. This provides the importance of mathematical training, as one of the fundamental, which primarily forms the skills of abstract thinking, analysis and synthesis. Thus, a new function of an educational institution arises in the process of providing educational services - the formation of a competence model of professional education of specialists. The article substantiates the expediency of introducing mathematical modeling based on Mathcad in the process of forming professional competence of future economists. The essence of the concepts of "professional competence" and "mathematical competence" of future economists are considered. It is argued that mathematical training is an important component of professional competence. Today, it is the results of mathematical modeling of real processes that generate the most progressive directions of development in science and technology. Therefore, the concept of an economic-mathematical model plays a fundamental role in the training of economists. The formation of professional competence of future economists, anticipating the integration of professional and personal development, should be carried out using mathematical modeling, starting with junior courses. However, despite the fact that the mathematical model of the process or phenomenon being studied in economics is always its generalized abstract reflection, the mathematical apparatus used is usually quite cumbersome. This is a significant obstacle in strengthening the applied orientation of mathematics in the first years. In our opinion, one of the effective ways to eliminate certain contradictions is the introduction of information technologies The purpose of this publication is to substantiate the feasibility of introducing mathematical modeling based on Mathcad in the process of forming professional competence of future economists, to determine the main didactic requirements and explore the impact of technology on the main components of mathematical training: motivational-value, cognitive, operational-activity, communicative. On the basis of what was studied, we concluded that for a specific specialty it is worth highlighting professionally significant topics, questions, concepts of classical sections of mathematics, which have their application in professionally-oriented disciplines. The introduction from the first course of professional-oriented tasks related to the specialty, even at the level of the simplest models, allows you to implement the principle of continuity in learning. Since the new content of mathematical disciplines becomes a reliable base for the study of professionally-oriented, within which more complex models are studied, with the help of which the key problems of the future profession are solved In the process of mathematical training of specialists, we used the universal integrated system Mathcad, which allows you to simply and visually enter the original data, carry out the traditional mathematical description of solutions and get the results of calculations using graphical interpretation. This made it possible to consider the simplest mathematical models and, using a complex mathematical apparatus, to develop universal models and algorithms. The main mathematical models of economic systems that are appropriate to consider in mathematical courses are highlighted. Examples of mathematical modeling based on Mathcad are given. The advantages of introducing mathematical modeling into the process of professional training are demonstrated. On the basis of the study, conclusions were drawn that mathematical modeling based on Mathcad allows to improve the main components of the process of mathematical preparation: - motivational and value (the formation of a sustained interest in the mastery of mathematical knowledge and information technology with a view to their application in professional and research activities); - cognitive (obtaining fundamental knowledge from the classical sections of mathematics and the ability to apply them in the process of mathematical modeling) - operational-activity (self-realization in professional activity by means of mathematical modeling based on the integration of knowledge across professional-oriented and mathematical disciplines using information technologies); - communicative (possession of ways of presenting the results of its activity-communicative (possession of ways of presenting the results of its activities). The study showed that the introduction of mathematical modeling should provide the following didactic requirements: - a fairly correct idea of ​​the teacher about the holistic picture of the future educational and professional activities of the student; - definition of goals and purpose of the introduced new content in the content of mathematical disciplines; - Compliance of the learning task with the ideas of the personal approach (updating the personal functions of specialists, consistency with the problems of practical training in production); - approbation of the skills and skills produced in practice. This allows you to organize student-centric education.


Author(s):  
Yiqi Zhang ◽  
Changxu Wu

The current paper provided a tutorial of the integration of mathematical models in human performance modeling. It introduced the unique features of mathematical modeling in human performance, and the steps in mathematical model integration, including how the literature of models was reviewed, how a research gap was identified, and how a mathematical model was developed and integrated based on existing models, and how a model was validated via an experimental study. A case study was presented by following each step to illustrate the integration of several existing models to derive a new model of drivers’ braking performance in warning response with its integration with the existing mathematical models of driver speed control in normal situations and the model of humans’ warning response time. This is the first tutorial work that provided a detailed explanation of the steps in mathematical model integration with a case study in human performance modeling. It could be used as guidance for human factors professionals to learn the mathematical modeling approaches and will benefit the field of human performance modeling.


2016 ◽  
Vol 7 (3) ◽  
pp. 1271
Author(s):  
Jorge Guerra Pires

The ambition of this document is to set in evidence the prerequisite for integrative (mathematical) models, mechanism-based models, for appetite/bodyweight control. For achieving this goal, it is provided a scrutinized literature review and it is organized them in such a way to make the point. The quantitative methods exploited by the authors are called differential equations solved numerically; they are discussed briefly since it is not our goal herein to handle details. On the current state of the art, there is no mathematical model to the best of the author’s knowledge targeting at integrating several hormones at once in mathematical descriptions: even for single hormones, the literature is either occasional or do not exist at all; it is depicted some results for simple models already built. As it can be seen, the functions and roles seem fuzzy, most hormones seem to be piloting the same undertaking. The key challenge from a mathematical modeling perspective is how to separate properly the mechanisms of each hormone. The kind of pursuit presented herein could initiate an imperative cascade of mathematical modeling applied to metabolism of bodyweight control and energy homeostasis.


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