scholarly journals Memory-Dependent Model for the Dynamics of COVID-19 Pandemic

2020 ◽  
Author(s):  
K.M. Furati ◽  
I.O. Sarumi ◽  
A.Q.M. Khaliq
Keyword(s):  
Fractional Order ◽  
Public Perception ◽  
Model Simulation ◽  
Transmission Rate ◽  
Optimal Order ◽  
Dependent Model ◽  
Exponential Time Differencing Method ◽  
And Control ◽  
The Impact ◽  
Mean Square Errors

AbstractCOVID-19 pandemic has impacted people all across the world. As a result, there has been a collective effort to monitor, predict, and control the spread of this disease. Among this effort is the development of mathematical models that could capture accurately the available data and simulate closely the futuristic scenarios. In this paper, a fractional-order memory-dependent model for simulating the spread of COVID-19 is proposed. In this model, the impact of governmental action and public perception are incorporated as part of the time-varying transmission rate. The model simulation is performed using the two-step generalized exponential time-differencing method and tested for data from Wuhan, China. The mean-square errors demonstrate the merit of the fractional-order model and provide a good estimate of the optimal order.

scholarly journals Mapping altimetry in the forthcoming SWOT era by back-and-forth nudging a one-layer quasi-geostrophic model

2020 ◽  
Author(s):  
Florian Le Guillou ◽  
Sammy Metref ◽  
Emmanuel Cosme ◽  
Julien Le Sommer ◽  
Clément Ubelmann ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Large Scale ◽  
Model Simulation ◽  
Interpolation Method ◽  
Ocean Dynamics ◽  
Optimal Interpolation ◽  
Small Scale ◽  
Altimetric Data ◽  
The Impact ◽  
Mean Square Errors

AbstractDuring the past 25 years, altimetric observations of the ocean surface from space have been mapped to provide two dimensional sea surface height (SSH) fields which are crucial for scientific research and operational applications. The SSH fields can be reconstructed from conventional altimetric data using temporal and spatial interpolation. For instance, the standardDUACS products are created with an optimal interpolation method which is effective for both low temporal and low spatial resolution. However, the upcoming next-generation SWOT mission will provide very high spatial resolution but with low temporal resolution.The present paper makes the case that this temporal-spatial discrepancy induces the need for new advanced mapping techniques involving information on the ocean dynamics. An algorithm is introduced, dubbed the BFN-QG, that uses a simple data assimilation method, the back-and-forth nudging, to interpolate altimetric data while respecting quasigeostrophic dynamics. The BFN-QG is tested in an observing system simulation experiments and compared to the DUACS products. The experiments consider as reference the high-resolution numerical model simulation NATL60 from which are produced realistic data: four conventional altimetric nadirs and SWOT data. In a combined nadirs and SWOT scenario, the BFN-QG substantially improves the mapping by reducing the root-mean-square errors and increasing the spectral effective resolution by 40km. Also, the BFN-QG method can be adapted to combine large-scale corrections from nadirs data and small-scale corrections from SWOT data so as to reduce the impact of SWOT correlated noises and still provide accurate SSH maps.

scholarly journals Impact and Control of Reflected Noise from an Overpass Bottom

2018 ◽  
Vol 8 (10) ◽  
pp. 1908
Author(s):  
Chi-Chwen Lin ◽  
Yen-Ping Peng ◽  
Yung-Pin Tsai ◽  
Yu-Chen Chang ◽  
Ku-Fan Chen
Keyword(s):  
Noise Level ◽  
Sound Absorption ◽  
Noise Source ◽  
Model Simulation ◽  
Buffer Zone ◽  
Residential Area ◽  
Discernible Effect ◽  
Absorbing Material ◽  
And Control ◽  
The Impact

This study examines the effects of noise reflected from the overpass bottom under various conditions using onsite measurements and model simulation. Reflected noise from the overpass bottom may be as high as 8 dB(A). Bottom materials (steel and reinforced concrete (RC)) have no discernible effect on the reflected noise level. As the height of an overpass increases, the level of reflected noise decreases. When an overpass is parallel to the noise source (i.e., the freeway), the size of the area impacted by reflected noise increases. As the sound absorption rating of the material installed at the overpass bottom increased, the level of reflected noise decreased. A sound absorbing material with a sound absorption rate of at least 0.60 is recommended to reduce reflected noise level. When the distance between the overpass side and a receiver exceeded 30 m, the level of reflected noise level reduced significantly. Therefore, if the distance between a residential area and overpass could be increased to create a buffer zone coupled with the installation of sound absorbing material at the overpass bottom, the impact of reflected noise on nearby residents can be reduced.

scholarly journals Exploring perspectives on COVID-19 risk, protective behavior and control measures

2020 ◽  
Author(s):  
Karwan M Amen ◽  
Kazhan I. Mahmood ◽  
Sherzad A. Shabu ◽  
Nazar Shabila
Keyword(s):  
Risk Perception ◽  
Public Perception ◽  
Preventive Measures ◽  
Rank Order ◽  
Control Measures ◽  
Protective Behavior ◽  
Protective Measures ◽  
The People ◽  
And Control ◽  
The Impact

Abstract Background Understanding the public perception and behavior towards the spread of the coronavirus disease (COVID-19) can help in mitigating the transmission of the infection. This study aimed to assess the perspectives of the people towards COVID-19, especially concerning the risk of the disease, adherence to protective measures, and the effectiveness of the imposed prevention and control measures. Methods An explorative study based on Q-methodology was conducted in Erbil, Iraqi Kurdistan Region. The study involved a purposively selected sample of 40 persons representing different educational, social, and economic levels. Forty-one statements were extracted that have covered various aspects of the impact of COVID-19 on the life of people, and different perceptions and uncertainties around it. We asked the participants to rank-order the 41 statements into a distribution on a nine point scale, ranging from “least agree” to “most agree." Data analysis involved a by-person factor analysis using PQMethod 2.35, which aimed to identify the main viewpoints. Results The analysis revealed three distinct viewpoints and one consensus perspective for the people’s perspectives about COVID-19. Viewpoint 1, confidence and obedience to protective measures, centers on compliance with the main protective measures, the seriousness of COVID-19, and the effectiveness of the government's preventive measures. Viewpoint 2, apprehensiveness and noncompliance, focuses on extremely worry about the disease and concerns about the government measures against COVID-19. Viewpoint 3, people’s inattentiveness, emphasizes the lack of awareness and adherence to protective measures by the people and ineffectiveness of the government’s preventive measures. Conclusion The primary aspects distinguishing the three viewpoints focus on risk perception, protective behavioral response, and government’s preventive measures. Risk perception can guide appropriate protective behavior, but not always. For strengthening the preventive measures, and compliance with protective behaviors, different approaches that can address the needs of different groups of people are required. The focus should be on increasing the risk awareness, reducing anxiety, and explaining the justification and effectiveness of the government's preventive measures.

scholarly journals The impact of containment measures and air temperature on mitigating COVID-19 transmission: non-classical SEIR modeling and analysis

2020 ◽  
Author(s):  
Di Liu ◽  
Qidong Tai ◽  
Yaping Wang ◽  
Miao Pu ◽  
Sikai Ge ◽  
...  
Keyword(s):  
Air Temperature ◽  
Model Simulation ◽  
Transmission Rate ◽  
Mainland China ◽  
Contact Tracing ◽  
Modeling And Analysis ◽  
Optimal Temperature Range ◽  
Containment Measures ◽  
China Model ◽  
The Impact

Early non-pharmaceutical interventions (NPIs) are crucial to prevent and control of COVID-19 pandemic. We established a stochastic non-classical SEIR NPIs model (ScEIQRsh) which can quantify the three kinds of NPIs measures simultaneously to mimic the clustered intra-family or intra-acquaintance spreading pattern of COVID-19 under the effective integrated NPIs in Mainland China. Model simulation demonstrated that measures to diminish contactable susceptible (Sc), such as home confinement, travel constraint, social distancing etc. and measures to avoid delay of diagnosis and hospitalized isolation (η) were more effective but consumptive than contact tracing (κ, ρ). From fitted model by MCMC method, the proportion of asymptomatic infectors was 14.88% (IQR 8.17%, 25.37%). The association between air temperature and the fitted transmission rate (β) of COVID-19 suggests that COVID-19 pandemic would be seasonal with the optimal temperature range of 5℃-14℃ and peak of 10℃ for spreading, and vaccine is indispensable to ultimate prevention COVID-19.

scholarly journals Dynamical analysis of a fractional order model incorporating fear in the disease transmission rate of COVID-19

2020 ◽  
Vol 99 (99) ◽  
pp. 1-17
Author(s):  
Debasis Mukherjee Debasis Mukherjee ◽  
Chandan Maji
Keyword(s):  
Fractional Order ◽  
Disease Transmission ◽  
Transmission Rate ◽  
Three Dimensional ◽  
Dynamical Analysis ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Fear Effect ◽  
And Control ◽  
Disease Free

This paper deals with a fractional-order three-dimensional compartmental model with fear effect. We have investigated whether fear can play an important role or not to spread and control the infectious diseases like COVID-19, SARS etc. in a bounded region. The basic results on uniqueness, non-negativity and boundedness of the solution of the system are investigated. Stability analysis ensures that the disease-free equilibrium point is locally asymptotically stable if carrying capacity greater than a certain threshold value.We have also derived the conditions for which endemic equilibrium is globally asymptotically stable that means the disease persists in the system. Numerical simulation suggests that the fear factor is an important role which is observed through Hopf-bifurcation.

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

Research Participation Experiences of Informants of Suicide and Control Cases

Crisis ◽  
2010 ◽  
Vol 31 (5) ◽  
pp. 238-246 ◽  
Author(s):  
Paul W. C. Wong ◽  
Wincy S. C. Chan ◽  
Philip S. L. Beh ◽  
Fiona W. S. Yau ◽  
Paul S. F. Yip ◽  
...  
Keyword(s):  
Ethical Issues ◽  
Research Participation ◽  
Self Report ◽  
Initial Contact ◽  
Psychological Autopsy ◽  
Autopsy Study ◽  
The People ◽  
And Control ◽  
The Impact

Background: Ethical issues have been raised about using the psychological autopsy approach in the study of suicide. The impact on informants of control cases who participated in case-control psychological autopsy studies has not been investigated. Aims: (1) To investigate whether informants of suicide cases recruited by two approaches (coroners’ court and public mortuaries) respond differently to the initial contact by the research team. (2) To explore the reactions, reasons for participation, and comments of both the informants of suicide and control cases to psychological autopsy interviews. (3) To investigate the impact of the interviews on informants of suicide cases about a month after the interviews. Methods: A self-report questionnaire was used for the informants of both suicide and control cases. Telephone follow-up interviews were conducted with the informants of suicide cases. Results: The majority of the informants of suicide cases, regardless of the initial route of contact, as well as the control cases were positive about being approached to take part in the study. A minority of informants of suicide and control cases found the experience of talking about their family member to be more upsetting than expected. The telephone follow-up interviews showed that none of the informants of suicide cases reported being distressed by the psychological autopsy interviews. Limitations: The acceptance rate for our original psychological autopsy study was modest. Conclusions: The findings of this study are useful for future participants and researchers in measuring the potential benefits and risks of participating in similar sensitive research. Psychological autopsy interviews may be utilized as an active engagement approach to reach out to the people bereaved by suicide, especially in places where the postvention work is underdeveloped.

Using Work Domain Analysis to Evaluate the Impact of Digitization on Command and Control

2008 ◽  
Author(s):  
Daniel P. Jenkins ◽  
Neville A. Stanton ◽  
Paul M. Salmon ◽  
Guy H. Walker
Keyword(s):  
Command And Control ◽  
Domain Analysis ◽  
Work Domain Analysis ◽  
And Control ◽  
The Impact ◽  
Work Domain

Social and political dimension of stigmatization: The development of Natasha and Maria images for immigrants in Istanbul

2016 ◽  
Vol 13 (1) ◽  
pp. 159-168
Author(s):  
Bayram Unal
Keyword(s):  
Public Perception ◽  
Daily Life ◽  
Legal Framework ◽  
State Law ◽  
Migrant Women ◽  
Political Dimension ◽  
Security Forces ◽  
Official Discourse ◽  
The Third ◽  
The Impact

This study aims at understanding how the perceptions about migrants have been created and transferred into daily life as a stigmatization by means of public perception, media and state law implementations.  The focus would be briefly what kind of consequences these perceptions and stigmatization might lead. First section will examine the background of migration to Turkey briefly and make a summary of migration towards Turkey by 90s. Second section will briefly evaluate the preferential legal framework, which constitutes the base for official discourse differentiating the migrants and implementations of security forces that can be described as discriminatory. The third section deals with the impact of perceptions influential in both formation and reproduction of inclusive and exclusive practices towards migrant women. Additionally, impact of public perception in classifying the migrants and migratory processes would be dealt in this section.

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