TY  - JOUR
A1  - Bläsius, Thomas
A1  - Friedrich, Tobias
A1  - Krejca, Martin S.
A1  - Molitor, Louise
T1  - The impact of geometry on monochrome regions in the flip Schelling process
JF  - Computational geometry
N2  - Schelling's classical segregation model gives a coherent explanation for the wide-spread phenomenon of residential segregation. We introduce an agent-based saturated open-city variant, the Flip Schelling Process (FSP), in which agents, placed on a graph, have one out of two types and, based on the predominant type in their neighborhood, decide whether to change their types; similar to a new agent arriving as soon as another agent leaves the vertex. We investigate the probability that an edge {u,v} is monochrome, i.e., that both vertices u and v have the same type in the FSP, and we provide a general framework for analyzing the influence of the underlying graph topology on residential segregation. In particular, for two adjacent vertices, we show that a highly decisive common neighborhood, i.e., a common neighborhood where the absolute value of the difference between the number of vertices with different types is high, supports segregation and, moreover, that large common neighborhoods are more decisive. As an application, we study the expected behavior of the FSP on two common random graph models with and without geometry: (1) For random geometric graphs, we show that the existence of an edge {u,v} makes a highly decisive common neighborhood for u and v more likely. Based on this, we prove the existence of a constant c>0 such that the expected fraction of monochrome edges after the FSP is at least 1/2+c. (2) For Erdős–Rényi graphs we show that large common neighborhoods are unlikely and that the expected fraction of monochrome edges after the FSP is at most 1/2+o(1). Our results indicate that the cluster structure of the underlying graph has a significant impact on the obtained segregation strength.
KW  - Agent-based model
KW  - Schelling segregation
KW  - Spin system
Y1  - 2022
U6  - https://doi.org/10.1016/j.comgeo.2022.101902
SN  - 0925-7721
SN  - 1879-081X
VL  - 108
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Liu, Chun
A1  - Sibly, Richard M.
A1  - Grimm, Volker
A1  - Thorbek, Pernille
T1  - Linking pesticide exposure and spatial dynamics an individual-based model of wood mouse (Apodemus sylvaticus) populations in agricultural landscapes
JF  - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog
N2  - The wood mouse is a common and abundant species in agricultural landscape and is a focal species in pesticide risk assessment. Empirical studies on the ecology of the wood mouse have provided sufficient information for the species to be modelled mechanistically. An individual-based model was constructed to explicitly represent the locations and movement patterns of individual mice. This together with the schedule of pesticide application allows prediction of the risk to the population from pesticide exposure. The model included life-history traits of wood mice as well as typical landscape dynamics in agricultural farmland in the UK. The model obtains a good fit to the available population data and is fit for risk assessment purposes. It can help identify spatio-temporal situations with the largest potential risk of exposure and enables extrapolation from individual-level endpoints to population-level effects. Largest risk of exposure to pesticides was found when good crop growth in the "sink" fields coincided with high "source" population densities in the hedgerows.
KW  - Population dynamics
KW  - Pesticides
KW  - Ecological risk assessment
KW  - Habitat choice
KW  - Agent-based model
KW  - NetLogo
Y1  - 2013
U6  - https://doi.org/10.1016/j.ecolmodel.2012.09.016
SN  - 0304-3800
VL  - 248
IS  - 2
SP  - 92
EP  - 102
PB  - Elsevier
CY  - Amsterdam
ER  -