On Wednesday 18 November, 38 attendees joined an event entitled ‘Simulation modelling Crops, Crime and Critical Care’. We were lucky to hear talks from three speakers covering a variety of situations where simulation modelling has been applied.
Ann-Kristin Koehler is a Research Fellow in the Leeds School of Earth and Environment who has worked on crop modelling. She spoke about the General Large Area Model for annual crops (GLAM), which has been designed to operate on the spatial scales of global and regional climate models. It aims to simulate the impact of current sub-seasonal and inter-annual climate variability on crop growth and development. GLAM was designed to take advantages of empirical and process-based models, which allows it to cover large areas and to simulate non-linearities and interactions. Ann also presented a thought-provoking history of climate models that showed the interplay between the scale of the models, their users and the decisions they inform. The presentation closed with a discussion about how crop modelling can be enhanced by machine-learning techniques and remote sensing.
After our opening speaker, we hosted out Annual General Meeting. Last year’s minutes were accepted and we welcomed a new Ordinary Committee member. Our Treasurer stood down and with no nominations, our Secretary will take responsibilities for the duties. We had a packed year of face-to-face and online talks, with plans for 2021 already afoot. Members will be asked for their preferences and suggestions via membership emails and Twitter polls.
Our second speaker for the day was Verity Tether, a Doctoral researcher in the Leeds School of Geography who has used agent-based modelling to investigate crime patterns. She explained how agent-based models are used to represent crime-generating and crime-attracting clusters in geographic space. Verity introduced the topic of environmental criminology, which included ideas like edge effects where crime is more likely where regions meet. Her studies suggest that the mechanisms behind crime generators and attractors do not lead to the emergence of edge effects.
Verity also presented on the strengths and weakness of agent-based modelling. From a theoretical perspective, agent-based models do not test a theory, instead examine the extent to which the theory is possible (see Groff 2007). But they are very flexible, require few assumptions, and can test ideas that could not be tested in the real world.
Our final speaker was Tom Lawton, a Consultant in Critical Care & Anaesthesia and Head of Clinical Artificial Intelligence at Bradford Royal Infirmary. Tom modelled patient flows using discrete event simulation to robustly estimate the effectiveness of potential changes to an intensive care unit. Although the work he presented was pre-COVID, his clinical expertise enabled him to discuss his discrete-event simulation from a pre- and mid-COVID perspective.
Tom highlighted the idiosyncrasies of the data sources required to inform the model – a mixture of broad and deep data – and suggested which R resources can be used for discrete-event simulation.
The biggest learning from the model was how the rest of the hospital is affected by changes in intensive care unit organisation. Tom’s model has been applied to COVID research in Europe – something that Tom admits his model didn’t predict. As noted during the presentation, discrete-event simulation is a resampling method so we ask What would have happened in counter factual scenarios?, rather than predict the future. Helpfully, Tom has created some tutorials to create discrete-event simulations in R. They can be found at the Connected Bradford GitHub account.
Watch the meeting here:
Recordings of other talks are available on the Leeds-Bradford local group playlist within the RSS YouTube channel
Groff, ER, 2007. Simulation for theory testing and experimentation: An example using routine activity theory and street robbery. J. Quant. Criminol. 23, 75–103. https://doi.org/10.1007/s10940-006-9021-z
Ciarán McInerney, PhD, is secretary of the Leeds-Bradford local group. He is a research fellow in the School of Computing at University of Leeds and the NIHR Yorkshire & Humber Patient Safety Translational Research Centre, where he studies the design and evaluation of digital innovation for patient safety.