Here we have a basic SEIR model and we will investigate what changes would be appropriate for modelling the 2019 Coronavirus.  We add simple containment meassures that affect two paramenters, the Susceptible population and the rate to become infected.  The initial parametrization is based on the su

Here we have a basic SEIR model and we will investigate what changes would be appropriate for modelling the 2019 Coronavirus.

We add simple containment meassures that affect two paramenters, the Susceptible population and the rate to become infected.

The initial parametrization is based on the suggested current data. The initial population is set for Catalonia.

The questions that we want to answer in this kind of models are not the shape of the curves, that are almost known from the beginning, but, when this happens, and the amplitude of the shapes. This is crucial, since in the current circumstance implies the collapse of certain resources, not only healthcare.

The validation process hence becomes critical, and allows to estimate the different parameters of the model from the data we obtain. This simulation approach allows to obtain somethings that is crucial to make decisions, the causality. We can infer this from the assumptions that are implicit on the model, and from it we can make decisions to improve the system behavior.

Yes, simulation works with causality and Flows diagrams is one of the techniques we have to draw it graphically, but is not the only one. On https://sdlps.com/projects/documentation/1009 you can review soon the same model but represented in Specification and Description Language.

 Dynamics of Emergency Room Crowding with treatment spaces. Here we investigate the effect of constrained spaces and ignore any changes in treatment time or staffing effects. Many of the consequences occur before treatment with potential arrivals being turned away and arrivals leaving without being

Dynamics of Emergency Room Crowding with treatment spaces. Here we investigate the effect of constrained spaces and ignore any changes in treatment time or staffing effects. Many of the consequences occur before treatment with potential arrivals being turned away and arrivals leaving without being treated.  

Changing Organization Structures and Behaviours based on Paul Holmstrom's work . Link to CLDs 
Changing Organization Structures and Behaviours based on Paul Holmstrom's work . Link to CLDs 
9 months ago
 Adapted from Fig.4, from Ana V Diez Roux (2011)  Complex Systems Thinking May Help Us Transcend Current Impasses in Health Disparities Research  Am J Public Health 2011;101 1627-1634   http://ajph.aphapublications.org/cgi/content/abstract/101/9/1627?etoc

Adapted from Fig.4, from Ana V Diez Roux (2011) Complex Systems Thinking May Help Us Transcend Current Impasses in Health Disparities Research Am J Public Health 2011;101 1627-1634  http://ajph.aphapublications.org/cgi/content/abstract/101/9/1627?etoc

 Causal Loop Rich Picture unfolding from Repenning, N. and J. Sterman (2002). Capability Traps and Self-Confirming Attribution Errors in the Dynamics of Process Improvement. Administrative Science Quarterly, 47: 265 - 295. http://jsterman.scripts.mit.edu/docs/Repenning-2002-CapabilityTraps.pdf

Causal Loop Rich Picture unfolding from Repenning, N. and J. Sterman (2002). Capability Traps and Self-Confirming Attribution Errors in the Dynamics of Process Improvement. Administrative Science Quarterly, 47: 265 - 295. http://jsterman.scripts.mit.edu/docs/Repenning-2002-CapabilityTraps.pdf

From David Rees PhD dissertation "Developing a Theory of Implementation for
Better Chronic Health Management" Health Services Research
Centre, Victoria University of Wellington, New Zealand
From David Rees PhD dissertation "Developing a Theory of Implementation for Better Chronic Health Management" Health Services Research Centre, Victoria University of Wellington, New Zealand
 The effects of subsidies and incentives for private health insurance on the mix of public and private hospital use. The central role of adverse selection/moral hazard on private health insurance sustainability. See also  updated version  around 2017

The effects of subsidies and incentives for private health insurance on the mix of public and private hospital use. The central role of adverse selection/moral hazard on private health insurance sustainability. See also updated version around 2017

 The model starts in 1900. In the year 2000 you get the chance to set a new emission target and nominal time to reach it. Your aim is to have atmospheric CO2 stabilise at about 400 ppmv in 2100.  From Sterman, John D. (2008)   Risk Communication on Climate:  Mental Models and Mass Balance .  Science
The model starts in 1900. In the year 2000 you get the chance to set a new emission target and nominal time to reach it. Your aim is to have atmospheric CO2 stabilise at about 400 ppmv in 2100.  From Sterman, John D. (2008)  Risk Communication on Climate:  Mental Models and Mass Balance.  Science 322 (24 October): 532-533. Clone of IM-694 to run 1900 to 2100.
 Hypertension Generic Patient Flow Causal Loop Diagram version of Insight 305

Hypertension Generic Patient Flow Causal Loop Diagram version of Insight 305

 Inspiration for the model: The Last of Us, a video game for PlayStation 4.      In this example, we used a system dynamics model to predict ​a spread of a dangerous infection called Cordyceps Brain Infection, which is immune to any type of antibiotics. In the beginning, the virus was carried by onl
Inspiration for the model: The Last of Us, a video game for PlayStation 4. 

In this example, we used a system dynamics model to predict ​a spread of a dangerous infection called Cordyceps Brain Infection, which is immune to any type of antibiotics. In the beginning, the virus was carried by only one person (Infected), which inhaled spores from a plant called cordyceps fungus. 

The Infected show their first symptoms after two days, as the infection attacks higher brain functions, making the infected highly aggressive and incapable of reason or rational thoughts. 

The infection can be transmitted via bodily fluids; such as saliva, or by inhaling spores from the afore mentioned plant. 

It is believed that the infection can last up to 10 years, before the host dies. 

Parameters such as Infectivity, Contact Rate and Immunization Rate can be adjusted, but as we are dealing with a highly infectious disease, the starting values are 0.97 (infectivity - in 97% of the cases, the infection will spread to another host); 5 (each infected attacks 5 susceptible person per day); and 0.0001 (only 1 infected per 10,000 infected gets the treatment, as the vaccine can be afforded only by the richest people on the Earth). 

Simulation time is set to 50 years. The purpose of this model is to simulate what kind of an effect a deadly infection would have on World's population, if the medicine could not find a cure, or if the cure would be available only for the richest people on the Earth. 

The simulation result shows that the Earth's population has been decimated with the disease, and that there are only 7,5 million people left on Earth. 
From David Rees PhD dissertation "Developing a Theory of Implementation for
Better Chronic Health Management" Health Services Research
Centre, Victoria University of Wellington, New Zealand
From David Rees PhD dissertation "Developing a Theory of Implementation for Better Chronic Health Management" Health Services Research Centre, Victoria University of Wellington, New Zealand
 Nested multilevel inquiry across multiple levels of organization of biology concepts. Adapted from Knippels (2002) PhD Thesis at http://bit.ly/GGcKo1 . Note the similarity to the nested adaptive cycles of socio-ecological systems in IM 1169

Nested multilevel inquiry across multiple levels of organization of biology concepts. Adapted from Knippels (2002) PhD Thesis at http://bit.ly/GGcKo1 . Note the similarity to the nested adaptive cycles of socio-ecological systems in IM 1169

From David Rees PhD dissertation "Developing a Theory of Implementation for
Better Chronic Health Management" Health Services Research
Centre, Victoria University of Wellington, New Zealand
From David Rees PhD dissertation "Developing a Theory of Implementation for Better Chronic Health Management" Health Services Research Centre, Victoria University of Wellington, New Zealand
 SIR model with herd immunity - Metrics by Guy Laekman   A Susceptible-Infected-Recovered (SIR) disease model with herd immunity

SIR model with herd immunity - Metrics by Guy Laekman

A Susceptible-Infected-Recovered (SIR) disease model with herd immunity

This is an insight about food-born pathogens and what factors are affected by it's outbreaks. This is a huge issue that is not very well-known. The pathogens in food has been increasing their resistance to antibiotics by mutations. Because we are generally using antibiotics more each day, the resist
This is an insight about food-born pathogens and what factors are affected by it's outbreaks. This is a huge issue that is not very well-known. The pathogens in food has been increasing their resistance to antibiotics by mutations. Because we are generally using antibiotics more each day, the resistance in these pathogens is growing more rapidly then it did before.
 Created in James Madison University's ISAT 341 Simulation and Modeling course by Joseph Straub and Andrew Funkhouser. Based on Mark Heffernan's Glucose-Insulin Insight Maker     Glucose Insulin Model Info:  Translated from Hormone.stm in Dynamic Modeling in the Health Sciences James L hargrove, Spr

Created in James Madison University's ISAT 341 Simulation and Modeling course by Joseph Straub and Andrew Funkhouser. Based on Mark Heffernan's Glucose-Insulin Insight Maker


Glucose Insulin Model Info:

Translated from Hormone.stm in Dynamic Modeling in the Health Sciences James L hargrove, Springer 1998, Ch 24 p255-261, by Mark Heffernan.

 IM-1175 with computable arguments, based on ideas from Micropublications  paper  about Claims, Evidence, Representations and Context Networks

IM-1175 with computable arguments, based on ideas from Micropublications paper about Claims, Evidence, Representations and Context Networks

7 months ago