Abstracts of Paper's Published in 2021


In the following:

  1. Mark Ian Nelson. A model fix gone wrong: investigation of an SIS model with saturating treatment. International Journal of Mathematical Education in Science and Technology, 52(2), pages 299-309, 2021. https://doi.org/10.1080/0020739X.2020.1745916.

A model fix gone wrong: investigation of an SIS model with saturating treatment

Abstract

A textbook model of a contagious disease, the dynamics of which are represented by the SIS epidemic model with saturating treatment, is considered. I show that this model, as originally formulated, is not dimensionally consistent. The model can be fixed by including a dimensional constant a of value one (with units individuals-1). At first sight, it appears that this is a cosmetic book-keeping exercise that will have no flow-on effects on the analysis of the model. In fact, we will discover that setting the value a=1 individuals-1 produces very unrealistic outcomes and that the parameter must have value a << 1 individuals-1. Necessary skills for students to work through this model are an understanding of steady-state solutions and linearised stability for a scalar differential equation and, most importantly, an understanding of units.

Keywords: Modelling, SIS, steady-state solutions, units.

Mark Ian Nelson. A model fix gone wrong: investigation of an SIS model with saturating treatment. International Journal of Mathematical Education in Science and Technology, 52(2), pages 299-309, 2021. https://doi.org/10.1080/0020739X.2020.1745916.



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Page Created: 26th April 2021.
Last Updated: 21st April 2021.