scholarly journals Mathematical models and numerical simulations of a thermally expandable microballoon for plastic foaming

2013 ◽  
Vol 104 ◽  
pp. 220-227 ◽  
Author(s):  
Masayasu Fujino ◽  
Takashi Taniguchi ◽  
Yasuhiro Kawaguchi ◽  
Masahiro Ohshima
Keyword(s):  
Mathematical Models ◽  
Numerical Simulations ◽  
Plastic Foaming

scholarly journals Asymptotic Properties of One Mathematical Model in Food Engineering under Stochastic Perturbations

Mathematics ◽  
2021 ◽  
Vol 9 (23) ◽  
pp. 3013
Author(s):  
Leonid Shaikhet
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Wide Class ◽  
Asymptotic Properties ◽  
Nonlinear Mathematical Model ◽  
Simple Criterion ◽  
Stochastic Perturbations ◽  
Food Engineering ◽  
Nonlinear Mathematical Models

For the example of one nonlinear mathematical model in food engineering with several equilibria and stochastic perturbations, a simple criterion for determining a stable or unstable equilibrium is reported. The obtained analytical results are illustrated by detailed numerical simulations of solutions of the considered Ito stochastic differential equations. The proposed criterion can be used for a wide class of nonlinear mathematical models in different applications.

scholarly journals A Mathematical Model of Universal Basic Income and Its Numerical Simulations

Algorithms ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 331
Author(s):  
Maria Letizia Bertotti
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Real World ◽  
Poverty Alleviation ◽  
The Other ◽  
Nonlinear Ordinary Differential Equations ◽  
Basic Income ◽  
Market Society ◽  
Number Of Individuals

In this paper, an elementary mathematical model describing the introduction of a universal basic income in a closed market society is constructed. The model is formulated in terms of a system of nonlinear ordinary differential equations, each of which gives account of how the number of individuals in a certain income class changes in time. Societies ruled by different fiscal systems (with no taxes, with taxation and redistribution, with a welfare system) are considered and the effect of the presence of a basic income in the various cases is analysed by means of numerical simulations. The main findings are that basic income effectively acts as a tool of poverty alleviation: indeed, in its presence the portion of individuals in the poorest classes and economic inequality diminish. Of course, the issue of a universal basic income in the real world is more complex and involves a variety of aspects. The goal here is simply to show how mathematical models can help in forecasting scenarios resulting from one or the other policy.

Ecological networks: From structure to dynamics

2020 ◽  
pp. 143-160
Author(s):  
Sonia Kéfi
Keyword(s):  
Mathematical Models ◽  
Numerical Simulations ◽  
Network Structure ◽  
Ecological Systems ◽  
Ecological Networks ◽  
Ecological Communities ◽  
Ecological Dynamics ◽  
Structure And Dynamics ◽  
Different Types ◽  
Recent Developments

Ecological systems are undeniably complex, including many species interacting in different ways with each other (e.g., predation, competition, facilitation, parasitism). One way of visualizing, describing, and studying this complexity is to represent them as networks, where nodes are typically species and links are interactions between these species. The study of these networks allows understanding of the rules governing the topology of their links, and assessing how network structure drives ecological dynamics. Studies on different types of ecological networks have suggested that they exhibit structural regularities, which in turn affect network dynamics and resilience to perturbations. Although the use of networks to represent ecological communities dates back to the early stages of the discipline, the last two decades have seen rapid progresses in our understanding of ecological networks, as data are collected at a faster rate and better resolution, as metrics are continuously developed to better characterize network structure and as numerical simulations of mathematical models have allowed investigating how network structure and dynamics are related in more comprehensive and realistic ecological networks. This chapter describes some of the recent developments and challenges related to the study of ecological networks. After defining networks in general, and ecological networks more specifically, recent results regarding the structure of different types of ecological networks, and what is known about their dynamics and resilience, are presented.

Passive Suspension of a Working Machine Horizontal Platform

2014 ◽  
Vol 611 ◽  
pp. 3-9 ◽  
Author(s):  
Martin Orečný ◽  
Štefan Segla
Keyword(s):  
Mathematical Models ◽  
Dynamic Analysis ◽  
Numerical Simulations ◽  
Experimental Measurement ◽  
Angular Acceleration ◽  
Vertical Axis ◽  
Horizontal Plate ◽  
Passive Suspension ◽  
Kinematic Excitation ◽  
The Individual

The paper deals with a dynamic analysis of a passive suspension of a working machine horizontal platform and the two configurations of its suspension system. For the individual alternatives the mathematical models are formulated. The rigid horizontal platform is excited in two perpendicular horizontal directions by kinematic excitation, which was acquired by an experimental measurement of the displacements of the working machine cabin. For the arbitration of which configuration is better two criterions were considered. The first criterion was the effective displacement in two perpendicular directions of the suspended horizontal plate and its rotation around the vertical axis. The second criterion was the effective acceleration of the horizontal plate in two perpendicular directions and the angular acceleration around the vertical axis. The numerical simulations shown that the first alternative (marked as A) gives better results in the reduction of vibration.

A new mathematical model of the behaviour of a four-axle freight wagon with UIC single-link suspension

2011 ◽  
Vol 225 (6) ◽  
pp. 637-647 ◽  
Author(s):  
J Matej
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Dynamic Stability ◽  
Dry Friction ◽  
Dynamic Behaviour ◽  
Single Link ◽  
Freight Wagons

This paper analyses the lateral dynamic behaviour of a four-axle freight wagon with Union Internationale des Chemins de fer (UIC) single-link suspension where dry friction is used to damp oscillations. Mathematical models of the standard UIC single-link suspension have been prepared elsewhere according to non-smooth mechanics assumptions and implemented into established MBS programs. Numerical simulations of the motion of the four-axle freight wagon with a 200 kN static axleload have been performed on straight track according to methods appropriate for predicting the dynamic stability of freight wagons.

scholarly journals A SURVEY ON EXTENSIONS OF THE PURE GRAVITY SWING-BY MANEUVER

2021 ◽  
Vol 57 (2) ◽  
pp. 445-457
Author(s):  
A. F. S. Ferreira ◽  
R. V. de Moraes ◽  
A. F. B. A. Prado ◽  
O. C. Winter ◽  
V. M. Gomes
Keyword(s):  
Angular Momentum ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Body Problem ◽  
Restricted Three Body Problem ◽  
Three Body Problem ◽  
Pure Gravity ◽  
Celestial Bodies ◽  
Patched Conics ◽  
Three Body

The present paper surveys the more recent techniques related to the swingby maneuver, where a spacecraft changes its energy and angular momentum by passing close to celestial bodies. It is focused on the literature related to extensions of this maneuver, with emphasis in the powered version, where an impulse is applied to the spacecraft near the closest approach. Several mathematical models are considered, including the patched-conics approximation for analytical studies, and the restricted three-body problem for the numerical simulations. The main goal is to show the models and the main conclusions available in the literature for those maneuvers. Some key results are shown to discuss important aspects of this maneuver, including the analysis of the energy variation of the spacecraft, the behavior of the trajectories and other applications.

scholarly journals Numerical Simulations for Chemotaxis Models

2019 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Gurgen Dallakyan
Keyword(s):  
Numerical Methods ◽  
Mathematical Models ◽  
Numerical Simulations ◽  
Numerical Solutions ◽  
Chemotaxis Models

In the paper, we study the usage of numerical methods in solution of mathematical models of biological problems. More specifically, Keller-Segel type chemotaxis models are discussed, their numerical solutions by sweep and Lax-Friedrichs methods are obtained and interpreted biologically.

scholarly journals Tracking of Stiffness Variation in Structural Members Using Input Error Function Observers

2021 ◽  
Vol 11 (24) ◽  
pp. 11857
Author(s):  
Prasad Dharap ◽  
Satish Nagarajaiah
Keyword(s):  
Mathematical Models ◽  
Numerical Simulations ◽  
Structural Damage ◽  
Error Function ◽  
Structural Members ◽  
Input Output ◽  
Long Span ◽  
Long Span Bridge ◽  
Stiffness Variation ◽  
Input Error

This study evaluates input error function observers for tracking of stiffness variation in real-time. The input error function is an Analytical Redundancy (AR)-based diagnosis method and necessitates a mathematical model of the system and system identification techniques. In practice, mathematical models used during numerical simulations differ from the actual status of the structure, and thus, accurate mathematical models are rarely available for reference. Noise is an unwanted signal in the input–output measurements but unavoidable in real-world applications (as in long span bridge trusses) and hard to imitate during numerical simulations. Simulation data from the truss system clearly indicates the effectiveness of the proposed structural damage detection method for estimating the severity of the damage. Optimization of the input error function can further automate the stiffness estimation in structural members and address critical aspects such as system uncertainties and the presence of noise in input–output measurements. Stiffness tracking in one of the planar truss members indicates the potential of optimization of the input error function for online structural health monitoring and implementing condition-based maintenance.

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