Featured Presentations
IRMACS Series: 4th Annual Modelling of Complex Social Systems Symposium
Abstract
Many criminal street gangs are territorial in nature claiming compact geographic regions as their home turf. Gangs defend their territories both with the threat and use of violence. A neutral model based on spatial Lotka-Volterra competition equations shows that territories are strictly stable only where gangs are exactly symmetrical in all characteristics, which we interpret as a neutral condition. We test the model against data on violent crime involving thirteen street gangs in a region of Los Angeles. We find excellent agreement between model predictions and the observed spatial distribution of crime.
IRMACS Series: IMC Colloquium Series
Abstract
The most precious and powerful resources of any society are its' peoples. The social exclusion of large numbers of citizens creates unsustainable costs and simultaneously threatens the integrity and security of society. This talk focuses on recent initiatives designed to reduce social exclusion among identified sub-populations: the homeless; drug addicted offenders; and those who commit a high number of crimes in their communities. Current projects in British Columbia highlight innovative experiments in public policy, and incorporate a variety of empirical methods, including randomized controlled trials and population-evel data linkages....
IRMACS Series: Jonfest 2011
Abstract
The most basic issue in economic equibrium, concerning the exchange of goods by agents through a market, can be modeled as a variational inequality problem with the initial supplies of goods as parameters. The question arises then as to how the equilibrium prices and goods respond to shifts in those parameters. Results of variational analysis can be applied to get answers that, to many economists, are surprising.
It has long been understood that parametric instability can occur and undermine the price adjustment process by which economists might hope for an equilibrium to be achieved. However, it turns out that, under mild...
IRMACS Series: CRC Seminar Series
Abstract
Once it infects a cell, HIV-1 mutates at an exceptionally high rate. In addition, the HIV-1 genome integrates into the genome of the infected cell, allowing the virus to persist in a dormant state for long periods. While infected people can produce an effective immune response that clears the initial virus, its ability to hide from immune recognition, and to produce mutant offspring at a high frequency, allows the emergence of mutant viruses that can escape an on-going immune response. Typically, a new immune response is mounted to clear those mutants, but by the time it has done so, another wave of new mutants arises, and escapes the new...
