scholarly journals A Dynamical Modelling of the Epidemic Diseases to Assessing the Rates of Spread of COVID-19 in Saudi Arabia: SEIQR Model

2020 ◽  
Author(s):  
Hamdy Youssef ◽  
Najat Alghamdi ◽  
Magdy Ezzat ◽  
Alaa El-Bary ◽  
Ahmed Shawky
Keyword(s):  
Saudi Arabia ◽  
Reproductive Number ◽  
Adequate Treatment ◽  
New Approach ◽  
Safe Place ◽  
Epidemic Dynamics ◽  
Internal Parameters ◽  
The Stability ◽  
And Control ◽  
Epidemic Diseases

Abstract A model of critical epidemic dynamics for the emergence of the new coronavirus COVID-19 is being established in this paper. A new approach to the assessment and control of the COVID-19 epidemic is given with the SEIQR pandemic model. This paper uses real knowledge on the distribution of COVID-19 in Saudi Arabia for mathematical modeling and dynamic analyses. The reproductive number and detailed stability analysis are provided in the SEIQR model dynamics. In a Jacobian method of linearization, we will address the domain of the solution and the equilibrium situation based on the SEIQR model. The equilibrium and its importance have been proven, and a study of the stability of the equilibrium free from diseases has been implemented. The reproduction number was evaluated in accordance with its internal parameters. The Lyapunov theorem of stability has proven the global stability of the current model's equilibrium. The SEIQR model was contrasted by comparing the results based on the SEIQR model with the real COVID-19 spread data in Saudi Arabia. Numerical evaluation and predictions were given. The results indicate that the SEIQR model is a strong model for the study of the spread of epidemics, such as COVID-19. At the end of this work, we implemented an optimum protocol that can quickly stop the spread of COVID-19 among the Saudi populations. The key solution to slowing COVID-19 transmission is to stay home and bring sick persons as far as possible in a remote location or in a safe place. Ultimately, it is vital to offer safe and adequate treatment to ill people, and to avoid them, medications, tones, and nutrients should be provided to non-infected persons.

scholarly journals A New Dynamical Modelling of the Epidemic Diseases to Assessing the Rates of Spread of COVID-19 in Saudi Arabia: SEIRQ Model

2020 ◽  
Author(s):  
Hamdy Youssef ◽  
Najat Alghamdi ◽  
Magdy Ezzat ◽  
Alaa El-Bary ◽  
Ahmed Shawky
Keyword(s):  
Saudi Arabia ◽  
Reproductive Number ◽  
New Approach ◽  
Epidemic Dynamics ◽  
Internal Parameters ◽  
Model Dynamics ◽  
Dynamic Analyses ◽  
The Stability ◽  
And Control ◽  
Epidemic Diseases

Abstract A new model of critical epidemic dynamics for the emergence of the new coronavirus COVID-19 is being established in this paper. A new approach to the assessment and control of the COVID 19 epidemic is given with the SEIRQ pandemic model. This paper uses real knowledge on the distribution of COVID-19 in Saudi Arabia for mathematical modeling and dynamic analyses. The reproductive number and detailed stability analysis are provided in the SEIRQ model dynamics. In a Jacobian method of linearization, we will address the domain of the solution and the equilibrium situation based on the SEIRQ model. The equilibrium and its importance have been proven, and a study of the stability of the equilibrium free from diseases has been implemented. The reproduction number was evaluated in accordance with its internal parameters. The Lyapunov theorem of stability has proven the global stability of the current model's equilibrium. The SEIRQ model was contrasted by comparing the results based on the SEIRQ model with the real COVID-19 spread data in Saudi Arabia. Numerical evaluation and predictions were given. The results indicate that the SEIRQ model is a strong model for the study of the spread of epidemics, such as COVID-19. At the end of this work, we implemented an optimum protocol that can quickly stop the spread of COVID-19 among the Saudi populations.

scholarly journals Psychometric Features of the General Teacher Test under the D-Scoring Model: The Case of Teacher Certification Assessment in Saudi Arabia

2018 ◽  
Vol 5 (2) ◽  
pp. 107
Author(s):  
Dimiter M. Dimitrov ◽  
Abdullah Alsadaawi
Keyword(s):  
Saudi Arabia ◽  
Teacher Certification ◽  
New Approach ◽  
Knowledge And Skills ◽  
Scoring Model ◽  
Test Scoring ◽  
Professional Teacher ◽  
Teacher Standards ◽  
The Stability ◽  
Teacher Test

<p><em>The teachers’ knowledge and skills on general standards under the Saudi National Professional Teacher Standards is assessed with the use of the General Teacher Test (GTT) administered by the National Center for Assessment (NCA) in Saudi Arabia. This paper examines the psychometric features of the GTT in the framework of a new approach to test scoring, referred to as D-scoring model, which is used with assessments at the NCA. The stability of such features across four test forms of the GTT is also examined. The study findings provide valuable information about the accuracy of the GTT scores and the validity of their interpretation and decisions regarding the licensure of teachers.</em></p>

A new approach to the stability and control of nonlinear processes

AIChE Journal ◽  
1964 ◽  
Vol 10 (1) ◽  
pp. 16-25 ◽  
Author(s):  
J. F. Leathrum ◽  
E. F. Johnson ◽  
L. Lapidus
Keyword(s):  
Nonlinear Processes ◽  
New Approach ◽  
Stability And Control ◽  
The Stability ◽  
And Control

A New Approach to Controlling Thermal Processes

1969 ◽  
Vol 2 (11) ◽  
pp. T181-T185 ◽  
Author(s):  
William K. Roots ◽  
Loren D. Meeker
Keyword(s):  
Transient Response ◽  
Closed Loop ◽  
Open Loop ◽  
Thermal Processes ◽  
New Approach ◽  
Plasma Torches ◽  
The Stability ◽  
Fluidised Beds ◽  
Response Determination ◽  
And Control

Roots and Wu (1967) established that meaningful models of common thermal processes (boilers without superheaters, furnaces, ovens, vats, kilns etc.) can be made from a cascade comprising an open-loop gain μ, a transit delay L, and a salient time constant T. They used this model to establish facile procedures for stability determination when such processes were closed-loop controlled. A new procedure is now presented that not only facilitates stability studies but also greatly simplifies transient response determination for all commands and disturbances likely to be encountered by such closed loop controlled processes. This new approach is based on a generalised parameter v that incorporates μ, L and T. Then by means of a new plane, the w plane, displays are presented that readily predict the stability criteria and the transient response for any practical combination of command and disturbance; as is shown by the examples contained in the Appendix. This has radically simplified the control amd instrumentation of the processes with which the authors are associated (induction furnaces, fluidised beds, plasma torches, zone refining, etc.) and the presentation is intended for industrial engineers concerned with the design and control of similar thermal processes.

scholarly journals A new approach on the modelling, chaos control and synchronization of a fractional biological oscillator

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Ali Saleh Alshomrani ◽  
Malik Zaka Ullah ◽  
Dumitru Baleanu
Keyword(s):  
Chaos Control ◽  
Control Method ◽  
Phase Portraits ◽  
New Approach ◽  
Control Scheme ◽  
Biological Oscillator ◽  
The Stability ◽  
Control And Synchronization ◽  
And Control ◽  
Active Control Method

AbstractThis research aims to discuss and control the chaotic behaviour of an autonomous fractional biological oscillator. Indeed, the concept of fractional calculus is used to include memory in the modelling formulation. In addition, we take into account a new auxiliary parameter in order to keep away from dimensional mismatching. Further, we explore the chaotic attractors of the considered model through its corresponding phase-portraits. Additionally, the stability and equilibrium point of the system are studied and investigated. Next, we design a feedback control scheme for the purpose of chaos control and stabilization. Afterwards, we introduce an efficient active control method to achieve synchronization between two chaotic fractional biological oscillators. The efficiency of the proposed stabilizing and synchronizing controllers is verified via theoretical analysis as well as simulations and numerical experiments.

scholarly journals Dynamics of the Rumor-Spreading Model with Control Mechanism in Complex Network

2022 ◽  
Vol 2022 ◽  
pp. 1-17
Author(s):  
Wei Zhang ◽  
Hongyong Deng ◽  
Xingmei Li ◽  
Huan Liu
Keyword(s):  
Social Order ◽  
Real Life ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Rumor Spreading ◽  
Unique Existence ◽  
Spreading Model ◽  
The Stability ◽  
And Control ◽  
Theoretical Results

The spread of rumors has a great impact on social order, people’s psychology, and life. In recent years, the application of rumor-spreading models in complex networks has received extensive attention. Taking the management and control of rumors by relevant departments in real life into account, the SIDRQ rumor-spreading model that combines forgetting mechanism, immune mechanism, and suspicion mechanism and guides on a uniform network is established in this paper. Then, the basic reproductive number of the system and the unique existence of the solution are discussed, and the stability of the system is analyzed using the basic reproductive number, Lyapunov function, and Lienard and Chipart theorem; furthermore, the basic reproductive number may not be able to deduce the stability of the system and a counterexample is given. Finally, the influence of different parameters on the spread of rumors is studied, and the validity of the theoretical results is verified.

scholarly journals MRCA time and epidemic dynamics of the 2019 novel coronavirus

2020 ◽  
Author(s):  
Chi Zhang ◽  
Mei Wang
Keyword(s):  
Common Ancestor ◽  
Bayesian Framework ◽  
Recent Common Ancestor ◽  
Reproductive Number ◽  
Epidemic Dynamics ◽  
Most Recent Common Ancestor ◽  
Median Estimate ◽  
Novel Coronavirus ◽  
And Control ◽  
Over Time

AbstractThe 2019 novel coronavirus (2019-nCoV) have emerged from Wuhan, China. Studying the epidemic dynamics is crucial for further surveillance and control of the outbreak. We employed a Bayesian framework to infer the time-calibrated phylogeny and the epidemic dynamics represented by the effective reproductive number (Re) changing over time from 33 genomic sequences available from GISAID. The time of the most recent common ancestor (MRCA) was December 17, 2019 (95% HPD: December 7, 2019 – December 23, 2019). The median estimate of Re shifted from 1.6 to 1.1 on around January 1, 2020. This study provides an early insight of the 2019-nCoV epidemic. However, due to limited amount of data, one should be cautious when interpreting the results at this stage.

scholarly journals Epidemic Dynamics of a Fractional-Order SIS Infectious Network Model

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Na Liu ◽  
Yunliu Li ◽  
Junwei Sun ◽  
Jie Fang ◽  
Peng Liu
Keyword(s):  
Fractional Order ◽  
Network Model ◽  
Large Scale ◽  
Equilibrium Points ◽  
Transmission Dynamics ◽  
Economic Losses ◽  
Epidemic Dynamics ◽  
Order Coefficient ◽  
The Stability ◽  
And Control

Outbreak and large-scale of the infectious diseases have caused enormous economic losses to all countries in the world. Constructing a network model which could reflect the transmission dynamics of the epidemics and investigating their transmission laws have a significant meaning in the precaution and control of the epidemics. In this article, a fractional-order SIS epidemic network model is proposed. First, an expression of the basic reproduction number is deduced. Second, applying the Lyapunov function, the stability of the equilibrium points about the infectious model is analyzed in detail. Finally, an example is present to verify the theoretical analysis. Furthermore, on account of the fractional-order coefficient, its influence on the transmission dynamics is also exhibited.

scholarly journals NUMERICAL APPROACH FOR SIMULATING THE TENSIONING PROCESS OF COMPLEX PRESTRESSED CABLE-NET STRUCTURES

2021 ◽  
Vol 27 (8) ◽  
pp. 571-578
Author(s):  
Deshen Chen ◽  
Yan Zhang ◽  
Hongliang Qian ◽  
Huajie Wang ◽  
Xiaofei Jin
Keyword(s):  
Mutual Effect ◽  
Numerical Approach ◽  
Vector Form ◽  
Form Finding ◽  
New Approach ◽  
Matrix Operations ◽  
Forming Accuracy ◽  
The Stability ◽  
And Control ◽  
Prestressed Cable

The stability of cable-net structures depends on the prestress of the system. Due to the large displacement and mutual effect of the cables, it is difficult to simulate the tensioning process and control the forming accuracy. The Backward Algorithm (BA) has been used to simulate the tensioning process. The traditional BA involves complicated and tedious matrix operations. In this paper, a new numerical method based on the Vector Form Intrinsic Finite Element (VFIFE) method is proposed for BA application. Moreover, the tensioning sequence of a complex cable-net structure is introduced. Subsequently, a new approach for BA application in the simulation of the tensioning process is presented, which combines the VFIFE approach and the notion of form-finding. Finally, a numerical example is simulated in detail and the results of different tensioning stages are analyzed to verify the feasibility of the proposed approach. This study provides a significant reference for improving the construction control and forming accuracy of complex prestressed cable-net structures.

scholarly journals Modeling the Epidemic Dynamics and Control of COVID-19 Outbreak in China

2020 ◽  
Author(s):  
Shilei Zhao ◽  
Hua Chen
Keyword(s):  
Clinical Evidence ◽  
Control Measures ◽  
Reproductive Number ◽  
Ode Model ◽  
Intervention Effects ◽  
Epidemic Dynamics ◽  
Dynamics And Control ◽  
Multiple Characteristics ◽  
New Diagnosis ◽  
And Control

BackgroundThe coronavirus disease 2019 (COVID-19) is rapidly spreading in China and more than 30 countries over last two months. COVID-19 has multiple characteristics distinct from other infectious diseases, including high infectivity during incubation, time delay between real dynamics and daily observed number of confirmed cases, and the intervention effects of implemented quarantine and control measures.MethodWe develop a Susceptible, Un-quanrantined infected, Quarantined infected, Confirmed infected (SUQC) model to characterize the dynamics of COVID-19 and explicitly parameterize the intervention effects of control measures, which is more suitable for analysis than other existing epidemic models.ResultsThe SUQC model is applied to the daily released data of the confirmed infections to analyze the outbreak of COVID-19 in Wuhan, Hubei (excluding Wuhan), China (excluding Hubei) and four first-tier cities of China. We found that, before January 30th, 2020, all these regions except Beijing had a reproductive number R > 1, and after January 30th, all regions had a reproductive number R < 1, indicating that the quarantine and control measures are effective in preventing the spread of COVID-19. The confirmation rate of Wuhan estimated by our model is 0.0643, substantially lower than that of Hubei excluding Wuhan (0.1914), and that of China excluding Hubei (0.2189), but jumps to 0.3229 after Feb 12th when clinical evidence was adopted in new diagnosis guidelines. The number of un-quarantined infected cases in Wuhan on February 12, 2020 is estimated to be 3,509 and declines to 334 on February 21th, 2020. After fitting the model with data as of February 21th, 2020, we predict that the end time of COVID-19 in Wuhan and Hubei is around late March, around mid March for China excluding Hubei, and before early March 2020 for the four tier-one cities. A total of 80,511 individuals are estimated to be infected in China, among which 49,510 are from Wuhan, 17,679 from Hubei (excluding Wuhan), and the rest 13,322 from other regions of China (excluding Hubei). Note that the estimates are from a deterministic ODE model and should be interpreted with some uncertainty.ConclusionWe suggest that rigorous quarantine and control measures should be kept before early March in Beijing, Shanghai, Guangzhou and Shenzhen, and before late March in Hubei. The model can also be useful to predict the trend of epidemic and provide quantitative guide for other countries in a high risk of outbreak, such as South Korea, Japan, Italy and Iran.

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