scholarly journals Long-Time Analysis of a Time-Dependent SUC Epidemic Model for the COVID-19 Pandemic

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Youngjin Hwang ◽  
Soobin Kwak ◽  
Junseok Kim
Keyword(s):  
Mathematical Model ◽  
Epidemic Model ◽  
Numerical Experiments ◽  
Time Dependent ◽  
Test Results ◽  
Time Analysis ◽  
Transmission Parameter ◽  
Proposed Model ◽  
Long Time ◽  
Dependent Parameter

In this study, we propose a time-dependent susceptible-unidentified infected-confirmed (tSUC) epidemic mathematical model for the COVID-19 pandemic, which has a time-dependent transmission parameter. Using the tSUC model with real confirmed data, we can estimate the number of unidentified infected cases. We can perform a long-time epidemic analysis from the beginning to the current pandemic of COVID-19 using the time-dependent parameter. To verify the performance of the proposed model, we present several numerical experiments. The computational test results confirm the usefulness of the proposed model in the analysis of the COVID-19 pandemic.

Numerical Simulation of the Coffee-ring Effect Inside Containers with Time-dependent Evaporation Rate

2021 ◽  
Author(s):  
Hyundong Kim ◽  
Junxiang Yang ◽  
Sangkwon Kim ◽  
Chaeyoung Lee ◽  
Sungha Yoon ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Numerical Experiments ◽  
Evaporation Rate ◽  
Gravitational Force ◽  
Time Dependent ◽  
Coffee Ring ◽  
Proposed Model ◽  
Coffee Ring Effect ◽  
Ring Effect

Abstract In this work, using a mathematical model and numerical simulation, we investigate the effect of time-dependent evaporation rates on stripe formation inside containers, which is driven by the coffee-ring effect. The coffee particles inside a container move according to random walk and under the gravitational force. Because of the non-uniform evaporation rate, we can observe stripe formation inside a container filled with liquid carrying coffee particles. We perform various numerical experiments to demonstrate the proposed model can simulate the stripe formation in a container.

A novel mathematical model including the wetness parameter as a variable for prevention of pressure ulcers

2021 ◽  
pp. 095441192110485
Author(s):  
Fadime Öğülmüş Demircan ◽  
İbrahim Yücedağ ◽  
Metin Toz
Keyword(s):  
Mathematical Model ◽  
Pressure Ulcer ◽  
Pressure Ulcers ◽  
Ulcer Formation ◽  
Hospital Capacity ◽  
Proposed Model ◽  
Wide Range ◽  
Temperature And Humidity ◽  
Long Time ◽  
External Conditions

Pressure ulcers are injuries caused by external conditions such as pressure, friction, shear, and humidity resulting from staying in the same position for a long time in bedridden patients. It is a serious problem worldwide when assessed in terms of hospital capacity, nursing staff employment and treatment costs. In this study, we developed a novel mathematical model based on one of our previous models to prevent pressure ulcers or delay injuries. The proposed model uses a human thermal model that includes skin temperature, hypothalamus temperature, regional perspiration coefficient, and unconsciously loss of water amount. Moreover, in our model, we defined a variable wetness parameter in addition to the parameters, pressure, temperature, and humidity. The proposed model is mathematically defined in detail and tested for a wide range of parameters to show the model’s effectiveness in determining the pressure ulcer formation risk. The model is also compared with a model from the literature that based on only the general parameters, pressure, temperature, and humidity. The obtained results showed that the model determines the risk of the occurrence of the pressure ulcer more precisely than the compared one.

Generalized Mathematical Model of Controlled Linear Oscillating Mechatronic Device

1970 ◽  
Vol 108 (2) ◽  
pp. 55-60 ◽  
Author(s):  
A. Senulis ◽  
D. Eidukas ◽  
E. Guseinoviene
Keyword(s):  
Mathematical Model ◽  
Harmonic Analysis ◽  
Electromagnetic Force ◽  
Magnetic Circuit ◽  
Time Dependent ◽  
Voltage Converter ◽  
Current Feedback ◽  
Dependent Parameter ◽  
General Mathematical Model

This paper presents the general mathematical model of double-sided splingless linear oscillating mechatronic device – oscillating motor- ompressor which is supplied by thyristor voltage converter. The model presents possibilities to evaluate losses of the windings and losses in the magnetic circuit, nonlinear inductances, mutual inductances, special current feedback using harmonic analysis for the control, oscillations not only of the moving part, but also the “stator” oscillations. Also using this model such parameters can be calculated – oscillation centre drift, oscillating coordinates and velocities of mover and stator, all currents and voltages, electromagnetic force, harmonics of each time-dependent parameter. Ill. 7, bibl. 13 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.108.2.145

scholarly journals Student interactions during class activities: a mathematical model

2018 ◽  
Vol 9 (2) ◽  
pp. 91-105
Author(s):  
D. Brunetto ◽  
C. Andrà ◽  
N. Parolini ◽  
M. Verani
Keyword(s):  
Mathematical Model ◽  
Small Groups ◽  
Numerical Experiments ◽  
Opinion Dynamics ◽  
Mathematical Education ◽  
Student Interactions ◽  
Mathematics Classrooms ◽  
Proposed Model ◽  
And Mathematics ◽  
Different Levels

Abstract This paper aims at bridging Mathematical Modelling and Mathematics Education by studying the opinion dynamics of students who work in small groups during mathematics classrooms. In particular, we propose a model which hinges upon the pioneering work of Hegselmann and Krause on opinion dynamics and integrates recent results of interactionist research in Mathematical Education. More precisely, the proposed model incorporates the following features: 1) the feelings of each student towards the classmates (building upon the so-called \I can" -\you can" framework); 2) the different levels of preparation of the students; 3) the presence of the teacher, who may or may not intervene to drive the students towards the correct solution of the problem. Several numerical experiments are presented to assess the capability of the model in reproducing typical realistic scenarios.

Mathematical Model for the Tree Leaf Shape and Estimation of Leaf Mass

2012 ◽  
Vol 557-559 ◽  
pp. 2015-2020
Author(s):  
Yang Liu ◽  
Zhao Liu ◽  
Yu Zhang ◽  
Qian Yao Duan
Keyword(s):  
Mathematical Model ◽  
Numerical Experiments ◽  
Growth Regulation ◽  
Mass Density ◽  
Leaf Shape ◽  
Fibonacci Sequence ◽  
Leaf Mass ◽  
Proposed Model ◽  
Tree Leaf ◽  
The Relationship

The relationship between leaf shape and tree profile is discussed in this paper at first. Through analysis of Leonardo’s rule, Fibonacci sequence and growth regulation, we conclude that leaf shape is related to sunlight, tree profile, and the distribution of leaves. Then by constructing an integral equation of the leaf-mass density, a mathematical model is established to estimate leaf mass of a tree when the density nearly obeys gamma distribution. At last, some numerical experiments are presented to confirm the proposed model.

scholarly journals A flexible symplectic scheme for two-dimensional Schrödinger equation with highly accurate RBFS quasi-interpolation

Filomat ◽  
2019 ◽  
Vol 33 (17) ◽  
pp. 5451-5461 ◽  
Author(s):  
Shengliang Zhang ◽  
Liping Zhang
Keyword(s):  
Numerical Experiments ◽  
Time Integration ◽  
Time Dependent ◽  
High Order Accuracy ◽  
Two Dimensional ◽  
Computationally Efficient ◽  
Order Accuracy ◽  
Symplectic Scheme ◽  
Long Time ◽  
Long Time Integration

Based on highly accurate multiquadric quasi-interpolation, this study suggests a meshless symplectic procedure for two-dimensional time-dependent Schr?dinger equation. The method is highorder accurate, flexible with respect to the geometry, computationally efficient and easy to implement. We also present a theoretical framework to show the conservativeness and convergence of the proposed method. As the numerical experiments show, it not only offers a high order accuracy but also has a good performance in the long time integration.

ANALYSIS OF THE INFLUENCE OF SELECTED FACTORS ON THE CAPACITY OF THRUST SLIDING BEARINGS LUBRICATED WITH MAGNETIC FLUIDS

Tribologia ◽  
2017 ◽  
pp. 33-38 ◽  
Author(s):  
Wojciech HORAK ◽  
Józef SALWIŃSKI ◽  
Marcin SZCZĘCH
Keyword(s):  
Mathematical Model ◽  
Magnetic Induction ◽  
Experimental Validation ◽  
Magnetic Fluids ◽  
Fluid Density ◽  
Test Results ◽  
Sliding Bearings ◽  
Proposed Model ◽  
Bearing Load ◽  
Gap Height

The paper presents the results of modelling and experimental validation of a developed mathematical model, describing the influence of selected factors on the axial force generated by magnetic fluids used as lubricants in thrust slide bearings. The model takes into account the physical properties of the magnetic fluid (density, saturation magnetization), bearing geometry (diameter, gap height, magnetic induction in the gap), and bearing load. The proposed model has been validated by comparing the results obtained from the model with the experiments. Good model compatibility with the test results was obtained.

Rancang Bangun Sistem Komunikasi Data Antara Mikrokontroller Atmega8 Dengan Arduino Pada Mesin Roaster Coffe Digital

2020 ◽  
Vol 3 (2) ◽  
pp. 103-113
Author(s):  
Rachmad Ikhsan ◽  
Effendi Effendi
Keyword(s):  
Temperature Sensor ◽  
Data Communication ◽  
Test Results ◽  
Industry Standards ◽  
Long Time ◽  
Roasting Time

Roasting coffee manually is widely applied by coffee producers. This process takes a very long time and is less efficient in terms of productivity for industry standards. This machine  is equipped with a thermocouple sensor as a temperature sensor that will measure the temperature in the roasting cylinder, then equipped with a timer as a reminder of roasting time that ranges from 15 minutes at a temperature of 200 degrees Celsius, this machine  is also equipped with android as a timer controller on the coffee roaster machine. This machine is also equipped with a microcontroller and Bluetooth as a media transmitter and data receiver. From the test results obtained data that Bluetooth can be used for data communication between the microcontroller and Android with a distance of 30 meters in the room, and 12 meters outside the room. If it exceeds that distance, then Bluetooth will not respond back

In-Plane Flexible Ring Tire Model—Part 1: Modeling and Parameter Identification

2018 ◽  
Vol 46 (3) ◽  
pp. 174-219 ◽  
Author(s):  
Bin Li ◽  
Xiaobo Yang ◽  
James Yang ◽  
Yunqing Zhang ◽  
Zeyu Ma
Keyword(s):  
Static Load ◽  
Model Parameters ◽  
Tire Model ◽  
Test Results ◽  
Lumped Mass ◽  
Virtual Test ◽  
Proposed Model ◽  
Particle Swarm Method ◽  
Vehicle Dynamic Simulation ◽  
Flexible Ring

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.

THE DEVELOPMENT OF THE MATHEMATICAL MODEL OF PREDICTING THE INDICATORS OF ACCREDITATION OF TECHNICAL UNIVERSITIES IN THE RUSSIAN FEDERATION

2017 ◽  
pp. 27-38
Author(s):  
Olga Mikhaylovna Tikhonova ◽  
Alexander Fedorovich Rezchikov ◽  
Vladimir Andreevich Ivashchenko ◽  
Vadim Alekseevich Kushnikov
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Regression Model ◽  
Oriented Graph ◽  
Real Data ◽  
Educational Process ◽  
Proposed Model ◽  
Linear Differential ◽  
The University ◽  
The Mathematical Model

The paper presents the system of predicting the indicators of accreditation of technical universities based on J. Forrester mechanism of system dynamics. According to analysis of cause-and-effect relationships between selected variables of the system (indicators of accreditation of the university) there was built the oriented graph. The complex of mathematical models developed to control the quality of training engineers in Russian higher educational institutions is based on this graph. The article presents an algorithm for constructing a model using one of the simulated variables as an example. The model is a system of non-linear differential equations, the modelling characteristics of the educational process being determined according to the solution of this system. The proposed algorithm for calculating these indicators is based on the system dynamics model and the regression model. The mathematical model is constructed on the basis of the model of system dynamics, which is further tested for compliance with real data using the regression model. The regression model is built on the available statistical data accumulated during the period of the university's work. The proposed approach is aimed at solving complex problems of managing the educational process in universities. The structure of the proposed model repeats the structure of cause-effect relationships in the system, and also provides the person responsible for managing quality control with the ability to quickly and adequately assess the performance of the system.

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