The limits to growth structure is based on the basic growth structure. And, as should be obvious, nothing grows forever as growth requires resources. Those required resources become a limits to growth. See also Archetypes.

supply chain dynamics week 1 challenge - team 062

This is a simple model of Whitetail deer population growth based on Ganz et al., 2024 "White-tailed deer population dynamics in a multi predator landscape shaped by humans". This is simplified from the actual model, but uses the survival estimates and some of the predation information. The purpose is to understand how scientific models work, and to use this model to explore the relationship between cougar predation and reductions in deer-vehicle collisions as shown in Gilbert et al. 2016

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.

Parameters loosely based on Zhu, Y., Pan, X., Jia, Y., Yang, X., Song, X., Ding, J., Zhong, W., Feng, J., & Zhu, L. (2023) Exploring Route-Specific Pharmacokinetics of PFAS in Mice by Coupling in Vivo Tests and Physiologically Based Toxicokinetic Models. Environmental Health Perspectives, 131(12), 127012. https://doi.org/10.1289/EHP11969

La situación modelada expresa el crecimiento de las ventas impulsadas por la motivación y productividad, pero es frenada por el tamaño del nicho de mercado.