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2009-01-01

Derocher, Andrew E., Klanjscek, Tin, Molnár, Péter K., Lewis, Mark A., Obbard, Martyn E.

Many species experience large fluctuations in food availability and depend on energy from fat and protein stores for survival, reproduction and growth. Body condition and, more specifically, energy stores thus constitute key variables in the life history of many species. Several indices exist to...

2009-12-22

Frédéric M. Hamelin, Mark A. Lewis

In this paper, elements of differential game theory are used to analyze a spatially explicit home range model for interactingwolf packs when movement behavior is uncertain. The model consists of a system of partial differential equations whose parameters reflect the movement behavior of...

2016-01-01

Schlägel, Ulrike E, Lewis, Mark A.

When sampling animal movement paths, the frequency at which location measurements are attempted is a critical feature for data analysis. Important quantities derived from raw data, e.g. travel distance or sinuosity, can differ largely based on the temporal resolution of the data. Likewise, when...

2019-01-01

Mark A. Lewis, Zhisheng Shuai, P. van den Driessche

A general framework for threshold parameters in population dynamics is developed using the concept of target reproduction numbers. This framework identies reproduction numbers and other threshold parameters in the literature in terms of their roles in population control. The framework is applied...

2014-10-01

Potts, Jonathan R, Marie Auger-M´eth´e, Karl Mokross, Mark A. Lewis

Complex systems of moving and interacting objects are ubiquitous in the natural and social sciences. Predicting their behaviour often requires models that mimic these systems with sufficient accuracy, while accounting for their inherent stochasticity. Although tools exist to determine which of a...

2014

Wu, B., Newton, F., Kouritzin, Michael A.

A new class of discrete random fields designed for quick simulation and covariance inference under inhomogenous conditions is introduced and studied. Simulation of these correlated fields can be done in a single pass instead of relying on multi-pass convergent methods like the Gibbs Sampler or...

2003

Ballantyne, David, Wiersma, Jonathan, Kouritzin, Michael, Hailes, Jarett, Long, Hongwei

A hybrid weighted interacting particle filter, the selectively resampling particle filter (SERP), is used to detect and track multiple ships maneuvering in a region of water. The ship trajectories exhibit nonlinear dynamics and interact in a nonlinear manner such that the ships do not collide....

1994

Heunis, A.J., Kouritzin, Michael

Consider the following random ordinary differential equation: X˙ϵ(τ)=F(Xϵ(τ),τ/ϵ,ω)subject toXϵ(0)=x0, where {F(x,t,ω),t≥0} are stochastic processes indexed by x in Rd, and the dependence on x is sufficiently regular to ensure that the equation has a unique solution Xϵ(τ,ω) over the interval...

2014-01-01

Jonathan R. Potts, Mark A. Lewis

Territorial behaviour is widespread in the animal kingdom, with creatures seeking to gain parts of space for their exclusive use. It arises through a complicated interplay of many different behavioural features. Extracting and quantifying the processes that give rise to territorial patterns...

2011-01-01

DiBacco, C., Lewis, Mark A., Strasser, C. A.

Aim We set out to develop a temperature-and salinity-dependent mechanistic population model for copepods that can be used to understand the role of environmental parameters in population growth or decline. Models are an important tool for understanding the dynamics of invasive species; our model...