M-groupoid as a tool for investigating mathematical models of computers

1977 ◽  
Vol 1 (1) ◽  
pp. 71-91
Author(s):  
Jerzy Tiuryn
Keyword(s):  
Mathematical Models ◽  
Simple Approximation ◽  
Simplified Model ◽  
Suitable Choice ◽  
Iterative Systems

An M-groupoid is a simplified model of computer. The classes of M-groupoids, address machines, stored program computers and iterative systems are presented as categories – by a suitable choice of homomorphisms. It is shown that the first three categories are equivalent, whereas the fourth is weaker (it is not equivalent to the previous ones and it can easily be embedded in the category of M-groupoids). This fact proves that M-groupoids form an essentially better and reasonably simple approximation of more complicated models of computers than iterative systems.

Utilization Mathematical and Physical Models Derived Therefrom Real-Time Models for the Optimization of Heating Processes

2013 ◽  
Vol 58 (3) ◽  
pp. 981-985 ◽  
Author(s):  
I. Špička ◽  
M. Heger
Keyword(s):  
Mathematical Models ◽  
Real Time ◽  
Model Simulation ◽  
Optimization Algorithms ◽  
Physical Models ◽  
Simplified Model ◽  
Operating Data ◽  
Reheating Furnace ◽  
Accurate Model ◽  
Computationally Intensive

Abstract Heating of materials is energy and costly operations. On those reasons optimization is highly desirable. One of the possible solutions to optimize heating in real time is to use a large number of fast simulations on the basis of them the optimization algorithms have chosen the most appropriate option of the heating control. This solution implies the use of extremely fast but sufficiently accurate simplified mathematical models of heating, the structure and parameters of them are defined based on accurate modelling using computationally intensive but slower classical mathematical-physical models. Based on the operating data of the reheating furnace was build an accurate model of heating. Using the simplified model simulation of heating was done with different heating conditions with downtime during heating. Proposed algorithms including the simulations show that the proposed strategy leads to verifiable savings during heating.

scholarly journals Oscillation Susceptibility Analysis of the ADMIRE Aircraft along the Path of Longitudinal Flight Equilibriums in Two Different Mathematical Models

2009 ◽  
Vol 2009 ◽  
pp. 1-26 ◽  
Author(s):  
Stefan Balint ◽  
Agneta Maria Balint ◽  
Achim Ionita
Keyword(s):  
Mathematical Models ◽  
Structural Stability ◽  
General Model ◽  
Simplified Model ◽  
The Real ◽  
Susceptibility Analysis ◽  
Real Phenomenon ◽  
The Stability ◽  
Flight Model

The oscillation susceptibility of the ADMIRE aircraft along the path of longitudinal flight equilibriums is analyzed numerically in the general and in a simplified flight model. More precisely, the longitudinal flight equilibriums, the stability of these equilibriums, and the existence of bifurcations along the path of these equilibriums are researched in both models. Maneuvers and appropriate piloting tasks for the touch-down moment are simulated in both models. The computed results obtained in the models are compared in order to see if the movement concerning the landing phase computed in the simplified model is similar to that computed in the general model. The similarity we find is not a proof of the structural stability of the simplified system, what as far we know never been made, but can increase the confidence that the simplified system correctly describes the real phenomenon.

Handbook of Mathematical Models for Languages and Computation

2019 ◽  
Author(s):  
Alexander Meduna ◽  
Petr Horacek ◽  
Martin Tomko
Keyword(s):  
Mathematical Models

Dependence of Current Harmonics of Greenhouse Irradiators on Supply Voltage

2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva
Keyword(s):  
Mathematical Models ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Feasibility Studies ◽  
Power Losses ◽  
Voltage Level ◽  
Supply Networks ◽  
Current Harmonics ◽  
Cable Lines ◽  
Harmonic Composition

The article describes the results of the study concerning the effect of the voltage level on current harmonic composition in greenhouses irradiators. It is found that its change affects the level of current harmonics of all types of the studied greenhouse irradiators. With decrease of nominal supply voltage by 10 %, the total harmonic distortion THDi decreases by 9 % for emitters equipped with high pressure sodium lamps (HPSL), by 10 % for emitters with electrode-less lamps and by 3 % for LED based emitters. With increase of nominal supply voltage by 10 %, THDi increases by 23 % for lighting devices equipped with HPSL, by 10 % for irradiators with electrode-less lamps and by 3 % for LED based emitters. Therefore, changes of supply voltage cause the least effect on the level of current harmonics of LED based emitters and then the emitters with electrode-less lamps. Change of the level of supply voltage causes the greatest effect on the level of current harmonics of HPSL based irradiators. Mathematical models of dependence of THDi on the level of supply voltage for greenhouse emitters equipped with LED, electrode-less lamps and HPSL lamps were formulated. These mathematical models may be used for calculations of total current when selecting transformers and supply cable lines for greenhouse lighting devices, for design of new or reconstruction of existing irradiation systems of greenhouse facilities, and for calculation of power losses in power supply networks of greenhouse facilities during feasibility studies for energy saving and energy efficiency increasing projects.

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