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2008-01-01

Potapov, A. B., Lewis, Mark A.

We consider the model of invasion prevention in a system of lakes that are connected via traffic of recreational boats. It is shown that, in presence of an Allee effect, the general optimal control problem can be reduced to a significantly simpler stationary optimization problem of optimal...

2020-05-19

Stephanie J. Peacock, Martin Krkošek, Mark A. Lewis, Péter K. Molnár

Migrations allow animals to track seasonal changes in resources, find mates, and avoid harsh climates, but these regular, longdistance movements also have implications for parasite dynamics and animal health. Migratory animals have been dubbed “superspreaders” of infection, but migration can also...

2014-01-01

Jonathan R. Potts, Karl Mokross, Mark A. Lewis

Collective phenomena, whereby agent –agent interactions determine spatial patterns, are ubiquitous in the animal kingdom. On the other hand, movement and space use are also greatly influenced by the interactions between animals and their environment. Despite both types of interaction...

2010-01-01

MARK A. LEWIS, WILLIAM NELSON, CAILIN XU

A vigor-structured model for mountain pine beetle outbreak dy- namics within a forest stand is proposed and analyzed. This model explicitly tracks the changing vigor structure in the stand. All model parameters, other than beetle vigor preference, were determined by tting model components to...

2014

Kouritzin, Michael, Ren, Y.-X.

Let ℓ be Lebesgue measure and X=(Xt,t≥0;Pμ) be a supercritical, super-stable process corresponding to the operator −(−Δ)α/2u+βu−ηu2 on Rd with constants β,η>0 and α∈(0,2]. Put View the MathML source, which for each smallθ is an a.s. convergent complex-valued martingale with limit View the MathML...

2011-01-01

Fagan, W. F., Jin, Y., Bishop, J. G., Marleau, J. M., Lewis, Mark A.

The relative importance of plant facilitation and competition during primary succession depends on the development of ecosystem nutrient pools, yet the interaction of these processes remains poorly understood. To explore how these mechanisms interact to drive successional dynamics, we devised a...

2004

Zhao, Xingqiu, Long, Hongwei, McCrosky, Jesse, Kim, Surrey, Kouritzin, Michael

In this paper, we discuss multi-target tracking for a submarine model based on incomplete observations. The submarine model is a weakly interacting stochastic dynamic system with several submarines in the underlying region. Observations are obtained at discrete times from a number of sonobuoys...

2000

Ballantyne, David, Chan, Hubert, Kouritzin, Michael

Particle approximations are used to track a maneuvering signal given only a noisy, corrupted sequence of observations, as are encountered in target tracking and surveillance. The signal exhibits nonlinearities that preclude the optimal use of a Kalman filter. It obeys a stochastic differential...

2006-01-01

Chad M. Topaz, Andrea L. Bertozzi, Mark A. Lewis

We construct a continuum model for biological aggregations in which individuals experience long-range social attraction and short range dispersal. For the case of one spatial dimension, we study the steady states analytically and numerically. There exist strongly nonlinear states with compact...

2020-01-14

Peter D. Harrington, Mark A. Lewis

In marine systems, adult populations confined to isolated habitat patches can be connected by larval dispersal. Source–sink theory provides effective tools to quantify the effect of specific habitat patches on the dynamics of connected populations. In this paper, we construct the next-generation...