Simple Bass diffusion modified from Sterman Business Dynamics Ch9. Compare with the SI infectious disease model Insight  584 .

Simple Bass diffusion modified from Sterman Business Dynamics Ch9. Compare with the SI infectious disease model Insight 584.

 A simple glucose regulation causal loop diagram taken from Richard O. Foster, 1970: The Dynamics of blood sugar regulation, MSc thesis, MIT Dept of Electrical Engineering, available on the MIT System Dynamics Group Literature Collection and in the MIT Electronic Libraries. See  IM-587  for Addition

A simple glucose regulation causal loop diagram taken from Richard O. Foster, 1970: The Dynamics of blood sugar regulation, MSc thesis, MIT Dept of Electrical Engineering, available on the MIT System Dynamics Group Literature Collection and in the MIT Electronic Libraries. See IM-587 for Addition of Glucagon

A basic conceptual model to evaluate Government regulation of the food industry on community health and health & social costs. Would regulation have a negative impact on the overall budget in the short and longer term?
A basic conceptual model to evaluate Government regulation of the food industry on community health and health & social costs. Would regulation have a negative impact on the overall budget in the short and longer term?
 The dynamics of methadone treatment for intravenous opioid users. The major flows in this study were people cycling between being on methadone and off treatment. This is a minimal model of the insights from the more detailed modelling project described in   Monograph pdf

The dynamics of methadone treatment for intravenous opioid users. The major flows in this study were people cycling between being on methadone and off treatment. This is a minimal model of the insights from the more detailed modelling project described in  Monograph pdf

 Insight synthesis of exchanges to better understand the basis of this decision. Unstructured additions from GMcD 
 
  SystemsWiki Focus Page  
  LinkedIn VSI Discussion

Insight synthesis of exchanges to better understand the basis of this decision. Unstructured additions from GMcD

 Love affairs and Differential equations. From Michael J Radzicki (1993) Dyadic processes,tempestuous relationships, and system dynamics Syst. Dyn. Rev. 9 (1) :79-94 

Love affairs and Differential equations. From Michael J Radzicki (1993) Dyadic processes,tempestuous relationships, and system dynamics Syst. Dyn. Rev. 9 (1) :79-94 

 A model of the ladder of inference which shows how we short circuit reality based on the assumptions and beliefs we develop  IM-351 . Combined with the cyclical scientific process described by Gary An.

A model of the ladder of inference which shows how we short circuit reality based on the assumptions and beliefs we develop IM-351. Combined with the cyclical scientific process described by Gary An.

 Linked concept version of Tanner's Clinical Judgment Model used as a scaffolding to start modeling managing the deteriorating patient.

Linked concept version of Tanner's Clinical Judgment Model used as a scaffolding to start modeling managing the deteriorating patient.

 A rich picture representation of the interactions described in Producing Health Consuming HEalth Care and usually referred to as the EBM Model or Field Theory of Health

A rich picture representation of the interactions described in Producing Health Consuming HEalth Care and usually referred to as the EBM Model or Field Theory of Health

  Base del modelo territorial de Ciudad Hermosa   Una adaptación del URBAN1 Model from Navid Ghaffarzadegan, John Lyneis and George P Richardson's  How small system dynamics models can help the public policy process  at System Dynamics Review 27: 22-44 (2011) ( click here to view full paper ). 

Base del modelo territorial de Ciudad Hermosa

Una adaptación del URBAN1 Model from Navid Ghaffarzadegan, John Lyneis and George P Richardson's How small system dynamics models can help the public policy process at System Dynamics Review 27: 22-44 (2011) (click here to view full paper). 

 Regulation of resource allocation to production in response to inventory adequacy and delivery delay. A non-price-mediated resource allocation system. From Sterman JD Business Dynamics p172 Fig 5-27

Regulation of resource allocation to production in response to inventory adequacy and delivery delay. A non-price-mediated resource allocation system. From Sterman JD Business Dynamics p172 Fig 5-27

A SEIR Model of SARS Pandemic With Isolation and Quarantine, based on Introduction to Computational Science by Shiflet and Shiflet    Quarantine is when someone exposed to infected people, whether infected or not, and advised to stay at home.     Isolation is when someone exposed to infected people,
A SEIR Model of SARS Pandemic With Isolation and Quarantine, based on Introduction to Computational Science by Shiflet and Shiflet

Quarantine is when someone exposed to infected people, whether infected or not, and advised to stay at home.

Isolation is when someone exposed to infected people, get infected, detected, and send to hospital.

Assumption:
- No births
- Dead only caused by SARS
- Contact between susceptible and infected are constant. Contact does not affected by population density
- Quarantine factor for susceptible and exposed is same.
- Quarantine and isolation is fully efective. Someone who quarantined or isolated cannot transmit or exposed to SARS
- Someone who has already recovered from SARS gained fully effective immunity, thus cannot re-infected
 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.

83 11 months ago
 Kidney replacement therapy dynamics: causal loop diagram of the kidney dialysis and transplant model

Kidney replacement therapy dynamics: causal loop diagram of the kidney dialysis and transplant model

 From Evans RG and Stoddardt GL  1990 paper Soc Sci Med 31(12)1347-63 , also published in a book by Evans, Barer and Marmor, Why are some people healthy and others not?: The determinants of population health. To  IM-425  We add impacts of spending and a "Thermostat" setting for population health con

From Evans RG and Stoddardt GL  1990 paper Soc Sci Med 31(12)1347-63 , also published in a book by Evans, Barer and Marmor, Why are some people healthy and others not?: The determinants of population health. To IM-425 We add impacts of spending and a "Thermostat" setting for population health controlling health spending.

This is a first attempt at identifying the actors that may need to be involved in the development of the model - at one stage or other.
This is a first attempt at identifying the actors that may need to be involved in the development of the model - at one stage or other.
From Cultural Worldview and Preference for Childhood Vaccination Policy  PSJ Article   Nov 2014
From Cultural Worldview and Preference for Childhood Vaccination Policy PSJ Article  Nov 2014