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Physical Sciences and Mathematics Commons™
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- Bark Beetle Dynamics (2)
- Nonlinear Wave Behavior, Fronts and Phase Transitions (2)
- Anomalous ocular damage (1)
- Beam Collapse (1)
- Competition (1)
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- Dispersal and Invasion (1)
- Envelope equations (1)
- Forest Pest (1)
- Game (1)
- Generic front (1)
- Ghost Forests (1)
- Global Climate Change (1)
- Global Warming (1)
- Impact (1)
- MathBio Education (1)
- Mathematical modelling (1)
- Mountain Pine Beetle (1)
- Multiscale analysis (1)
- Phenology and Life History Dynamics (1)
- Reids paradox seed dispersal (1)
- Teach (1)
Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Multi-Scale Analysis Of Seed Dispersal Contributes Tothe Resolution Of Reid’S Paradox, James A. Powell, N. E. Zimmermann
Multi-Scale Analysis Of Seed Dispersal Contributes Tothe Resolution Of Reid’S Paradox, James A. Powell, N. E. Zimmermann
James A. Powell
‘‘Reid’s paradox’’ is the mismatch between theoretical estimates of invasion rates for plants and ‘‘observed’’ rates of plant migration, particularly in the Holocene postglacial migration northwards. While Reid couched his paradox in terms of the migration of oaks in Great Britain, observers have documented the same problem in a wide variety of species. In almost all cases, these authors suggest that occasional, long-distance events, probably mitigated by active dispersal factors (ants, birds, rodents) are responsible. Clark and co-workers have shown that order statistics can bridge the gap between theory and predictions, essentially using ‘‘fat-tailed’’ dispersal kernels raised to high powers …
Assessing The Impacts Of Global Climate Changeon Forest Pests, J. A. Logan, J. Reniere, James A. Powell
Assessing The Impacts Of Global Climate Changeon Forest Pests, J. A. Logan, J. Reniere, James A. Powell
James A. Powell
No abstract provided.
Ghost Forests, Global Warming And The Mountain Pine Beetle, J. A. Logan, James A. Powell
Ghost Forests, Global Warming And The Mountain Pine Beetle, J. A. Logan, James A. Powell
James A. Powell
No abstract provided.
Games To Teach Mathematical Modelling, James A. Powell, J. Cangelosi, A. M. Harris
Games To Teach Mathematical Modelling, James A. Powell, J. Cangelosi, A. M. Harris
James A. Powell
We discuss the use of in-class games to create realistic situations for mathematical modelling. Two games are presented which are appropriate for use in post-calculus settings. The first game reproduces predator{prey oscillations and the second game simulates disease propagation in a mixing population. When used creatively these games encourage students to model realistic data and apply mathematical concepts to understanding the data.
Beam Collapse As An Explanation Foranomalous Ocular Damage, James A. Powell, J. V. Moloney, A. C. Newell, R. A. Albanese
Beam Collapse As An Explanation Foranomalous Ocular Damage, James A. Powell, J. V. Moloney, A. C. Newell, R. A. Albanese
James A. Powell
The basic mathematical phenomena relevant to ocular damage caused by ultrashort laser pulses are discussed with the use of mathematical results and numerical modeling. The primary effects of nonlinear self-focusing and beam collapse are examined in the ocular safety context. Finite-time material response and group-velocity dispersion are discussed as possible mitigating factors. An argument is presented that indicates that the initial stages of beam collapse are essentially two-dimensional. Experiments are suggested that might help distinguish the most important contributing factors in the damage regime. The numerical methodology is detailed in an appendix.
Competition Between Generic And Nongeneric Fronts Inenvelope Equations, James A. Powell, A. C. Newell, C. K. R. T. Jones
Competition Between Generic And Nongeneric Fronts Inenvelope Equations, James A. Powell, A. C. Newell, C. K. R. T. Jones
James A. Powell
Arguments are presented for understanding the selection of the speed and the nature of the fronts that join stable and unstable states on the supercritical side of first-order phase transitions. It is suggested that from compact support, nonpositive-definite initial conditions, observable front behavior occurs only when the asymptotic spatial structure of a trajectory in the Galilean ordinary differential equation (ODE) corresponds to the most unstable temporal mode in the governing partial differential equation (PDE). This selection criterion distinguishes between a "nonlinear" front, which has its origin in the first-order nature of the bifurcation, and a "linear" front. The nonlinear front …