scholarly journals Modeling the Spread and Control of COVID-19

Systems ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 53
Author(s):  
Ashutosh Trivedi ◽  
Nanda Kishore Sreenivas ◽  
Shrisha Rao
Keyword(s):  
Herd Immunity ◽  
Black Box ◽  
Personal Hygiene ◽  
Confined Space ◽  
Real Situation ◽  
Seir Model ◽  
Agent Based ◽  
Social Distancing ◽  
The Difference ◽  
And Control

Data-centric models of COVID-19 have been attempted, but have certain limitations. In this work, we propose an agent-based model of the epidemic in a confined space of agents representing humans. An extension to the SEIR model allows us to consider the difference between the appearance (black-box view) of the spread of disease and the real situation (glass-box view). Our model allows for simulations of lockdowns, social distancing, personal hygiene, quarantine, and hospitalization, with further considerations of different parameters, such as the extent to which hygiene and social distancing are observed in a population. Our results provide qualitative indications of the effects of various policies and parameters, for instance, that lockdowns by themselves are extremely unlikely to bring an end to an epidemic and may indeed make things worse, that social distancing is more important than personal hygiene, and that the growth of infection is significantly reduced for moderately high levels of social distancing and hygiene, even in the absence of herd immunity.

scholarly journals Modeling the Spread and Control of COVID-19

2020 ◽  
Author(s):  
Ashutosh Trivedi ◽  
Nanda Kishore Sreenivas ◽  
Shrisha Rao
Keyword(s):  
Herd Immunity ◽  
Black Box ◽  
Personal Hygiene ◽  
Confined Space ◽  
Real Situation ◽  
Seir Model ◽  
Agent Based ◽  
Social Distancing ◽  
The Difference ◽  
And Control

ABSTRACTData-centric models of COVID-19 have been tried, but have certain limitations. In this work, we propose an agent-based model of the epidemic in a confined space of agents representing humans. An extension to the SEIR model allows us to consider the difference between the appearance (black-box view) of the spread of disease, and the real situation (glass-box view). Our model allows for simulations of lockdowns, social distancing, personal hygiene, quarantine, and hospitalization, with further considerations of different parameters such as the extent to which hygiene and social distancing are observed in a population. Our results give qualitative indications of the effects of various policies and parameters; for instance, that lockdowns by themselves are extremely unlikely to bring an end to an epidemic and may indeed make things worse, that social distancing matters more than personal hygiene, and that the growth of infection comes down significantly for moderately high levels of social distancing and hygiene, even in the absence of herd immunity.

scholarly journals Modelling transmission and control of the COVID-19 pandemic in Australia

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Sheryl L. Chang ◽  
Nathan Harding ◽  
Cameron Zachreson ◽  
Oliver M. Cliff ◽  
Mikhail Prokopenko
Keyword(s):  
Computational Simulation ◽  
International Travel ◽  
School Closures ◽  
Agent Based ◽  
Social Distancing ◽  
Fine Grained ◽  
Trade Offs ◽  
Travel Restrictions ◽  
High Level ◽  
And Control

Abstract There is a continuing debate on relative benefits of various mitigation and suppression strategies aimed to control the spread of COVID-19. Here we report the results of agent-based modelling using a fine-grained computational simulation of the ongoing COVID-19 pandemic in Australia. This model is calibrated to match key characteristics of COVID-19 transmission. An important calibration outcome is the age-dependent fraction of symptomatic cases, with this fraction for children found to be one-fifth of such fraction for adults. We apply the model to compare several intervention strategies, including restrictions on international air travel, case isolation, home quarantine, social distancing with varying levels of compliance, and school closures. School closures are not found to bring decisive benefits unless coupled with high level of social distancing compliance. We report several trade-offs, and an important transition across the levels of social distancing compliance, in the range between 70% and 80% levels, with compliance at the 90% level found to control the disease within 13–14 weeks, when coupled with effective case isolation and international travel restrictions.

scholarly journals Estimating the impact of interventions against COVID-19: from lockdown to vaccination

2021 ◽  
Author(s):  
James Thompson ◽  
Stephen Wattam
Keyword(s):  
Spatial Clustering ◽  
Herd Immunity ◽  
Contact Tracing ◽  
Agent Based Model ◽  
Seir Model ◽  
Agent Based ◽  
Resident Population ◽  
First Case ◽  
Equivalent Equation ◽  
The Impact

AbstractCoronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present a detailed agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination.Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020.Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model results, on average, in only around 23% of the resident population infected. Our simulations suggest that testing and contract tracing reduce cases substantially, but are much less effective at reducing deaths. Lockdowns appear very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low levels, with substantial levels of protection achieved with only 30% of the population immune. When vaccinating in midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy.We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19.

scholarly journals Estimating the impact of interventions against COVID-19: From lockdown to vaccination

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261330
Author(s):  
James Thompson ◽  
Stephen Wattam
Keyword(s):  
Spatial Clustering ◽  
Herd Immunity ◽  
Contact Tracing ◽  
Agent Based Model ◽  
Seir Model ◽  
Agent Based ◽  
Resident Population ◽  
First Case ◽  
Equivalent Equation ◽  
The Impact

Coronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present an agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination. Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020. Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model infects only around 23% of the resident population. Our simulations suggest that testing and contract tracing reduce cases substantially, but are less effective at reducing deaths. Lockdowns are very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low coverage, with substantial levels of protection achieved with only 30% of the population fully immune. When vaccinating in the midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy. We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19.

scholarly journals Low-Impact Social Distancing Interventions to Mitigate Local Epidemics of SARS-CoV-2

2020 ◽  
Author(s):  
Michael L. Jackson
Keyword(s):  
Nursing Home ◽  
Hospital Admissions ◽  
Herd Immunity ◽  
Nursing Home Residents ◽  
King County ◽  
Rapid Testing ◽  
School Closures ◽  
Agent Based ◽  
Social Distancing ◽  
Hospital Occupancy

AbstractBackgroundAfter many jurisdictions have implemented intensive social distancing to suppress SARS-CoV-2 transmission, the challenge now is to mitigate the ongoing COVID-19 epidemic without overburdening economic and social activities. This report explores “low-impact” interventions to mitigate SARS-CoV-2 with a minimum of social and economic disruption.MethodsAn agent-based model simulated the population of King County, Washington, with agents that interact in homes, schools, workplaces, and other community sites. SARS-CoV-2 transmission probabilities were estimated by fitting simulated to observed hospital admissions from February – May 2020. Interventions considered were (a) encouraging telecommuting; (b) reducing contacts to seniors and nursing home residents; (c) modest reductions to contacts outside of the home; (d) encouraging self-isolation of persons with COVID-19 symptoms; (e) rapid testing and household quarantining.ResultsIndividual interventions are not expected to have a large impact on COVID-19 hospitalizations. No intervention reduced COVID-19 hospitalizations by more than 12.7% (95% confidence interval [CI], 12.0% to 13.3%). Removing all interventions would result in nearly 42,000 COVID- 19 hospitalizations between June 2020 and January 2021, with peak hospital occupancy exceeding available beds 6-fold. Combining the interventions is predicted to reduce total hospitalizations by 48% (95% CI, 47-49%), with peak COVID-19 hospital occupancy of 70% of total beds. Targeted school closures can further reduce the peak occupancy.ConclusionsCombining low-impact interventions may mitigate the course of the COVID-19 epidemic, keeping hospital burden within the capacity of the healthcare system. Under this approach SARS-CoV-2 can spread through the community, moving toward herd immunity, while minimizing social and economic disruption.

scholarly journals Lockdown exit strategies and risk of a second epidemic peak: a stochastic agent-based model of SARS-CoV-2 epidemic in France

2020 ◽  
Author(s):  
Nicolas Hoertel ◽  
Martin Blachier ◽  
Carlos Blanco ◽  
Mark Olfson ◽  
Marc Massetti ◽  
...  
Keyword(s):  
Cumulative Incidence ◽  
Herd Immunity ◽  
Agent Based ◽  
Social Distancing ◽  
Viral Spread ◽  
Population Immunity ◽  
Incidence And Mortality ◽  
Potential Impact ◽  
Parameter Values ◽  
Nationwide Implementation

AbstractMost European countries have responded to the COVID-19 threat by nationwide implementation of barrier measures and lockdown. However, assuming that population immunity will build up through the epidemic, it is likely to rebound once these measures are relaxed, possibly leading to a second or multiple repeated lockdowns. In this report, we present results of epidemiological modelling that has helped inform policy making in France. We used a stochastic agent-based microsimulation model of the COVID-19 epidemic in France, and examined the potential impact of post-quarantine measures, including social distancing, mask-wearing, and shielding of the population the most vulnerable to severe COVID-19 infection, on the disease’s cumulative incidence and mortality, and on ICU-bed occupancy. The model calibrated well and variation of model parameter values had little impact on outcome estimates. While quarantine is effective in containing the viral spread, it would be unlikely to prevent a rebound of the epidemic once lifted, regardless of its duration. Both social distancing and mask-wearing, although effective in slowing the epidemic and in reducing mortality, would also be ineffective in ultimately preventing the overwhelming of ICUs and a second lockdown. However, these measures coupled with shielding of vulnerable people would be associated with better outcomes, including lower cumulative incidence, mortality, and maintaining an adequate number of ICU beds to prevent a second lockdown. Benefits would nonetheless be markedly reduced if these measures were not applied by most people or not maintained for a sufficiently long period, as herd immunity progressively establishes in the less vulnerable population.

Analysis of the horizontal structure of a measurement and control geodetic network based on entropy

2013 ◽  
Vol 62 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Maria Mrówczyńska
Keyword(s):  
Geodetic Network ◽  
The State ◽  
Observation System ◽  
Optimum Number ◽  
Optimum Structure ◽  
Horizontal Structure ◽  
The Difference ◽  
And Control ◽  
Measurement And Control ◽  
Horizontal Displacements

Abstract The paper attempts to determine an optimum structure of a directional measurement and control network intended for investigating horizontal displacements. For this purpose it uses the notion of entropy as a logarithmical measure of probability of the state of a particular observation system. An optimum number of observations results from the difference of the entropy of the vector of parameters ΔHX̂ (x)corresponding to one extra observation. An increment of entropy interpreted as an increment of the amount of information about the state of the system determines the adoption or rejection of another extra observation to be carried out.

Selbstdifferenz in Praktiken

2017 ◽  
Vol 2017 (2) ◽  
pp. 57-76 ◽  
Author(s):  
Thomas Bedorf
Keyword(s):  
Practice Theory ◽  
Black Box ◽  
Lived Body ◽  
Material Body ◽  
Theories Of Practice ◽  
The Difference

The materiality of bodies is crucial for establishing theories of practice. To unfold the ‘black box’ of the performing body some theorists have implemented the difference between the lived body and the material body (Leib/Kçrper) in practice theory. This corporeal difference finds one systematic origin in phenomenology. It has come under attack for naturalising and subjectivising the lived body as a primordial category, and thus being unable to integrate to practice theory. It will be argued that critics can be refuted insofar as the corporeal difference is taken serious as a bodily experienced difference which is never to be reduced to some kind of objectivity.

PENINGKATAN KEMANDIRIAN BELAJAR SISWA SMP MELALUI PEMBELAJARAN BERBASIS MASALAH

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Tanti Jumaisyaroh Siregar
Keyword(s):  
Problem Based Learning ◽  
Mathematic Teacher ◽  
Self Regulated Learning ◽  
Regulated Learning ◽  
Quasi Experimental ◽  
Independent Variable ◽  
Direct Learning ◽  
The Difference ◽  
And Control ◽  
Learning Data

The purposes of this research were to know: the difference of improvement in self-regulated learning of students that given problem-based learning with students that given  direct learning. The type of this research is a quasi-experimental research by taking samples from the existing population. The variable of this research consist of independent variable that is problem based learning model while the dependent variable isself regulated learning of student.The population of this research is all students of SMP Swasta Ar-rahman Percut and the sample of this research is grade eight with taken sample two classes (experiment and control)  with total 60 students. The instrument of this research were: scale of self-regulated learning. Data that have been collected then analyzed and performed hypothesis testing by using T-test. Based of the results analysis, it showed that: improvment  of the students’ self-regulated learning that given problem-based learning was higher than the students’ ability that given direct learning His then, suggested that problem-based learning be used as an alternative for mathematic teacher to improved students’ ability in mathematical critical thinking and self-regulated learning.

Sign in / Sign up

Export Citation Format

Share Document