455 Diary










Class Date

Class #

HW

Topics explored

Source



due



Tue, Jan 18, 05

1


Nonoverlapping generations, Malthusian (geometric) growth, struggle for existence, logistic map

JR handout

Thu, Jan 20, 05

2


Maple Orientation I (in computer lab, Hochstetter 139). Numerical exploration of logistic map dynamics.

JR handout

Tue, Jan 25, 05

3


Fixed points, attracting and repelling, conjugacy of maps, Hartman-Grobman theorem, slope criterion for attraction/repulsion, range of existence & stability of positive f.p. in logistic map

JR handout

Thu, Jan 27, 05

4


Periodic points, analysis of period-2 in logistic map, conjugacy of logistic (r=4) map with tent map, sensitive dependence on ICs / butterfly effect, cannibalism model

JR handout

Tue, Feb 1, 05

5

HW1

Small-group development of discrete-time models of age-structured populations.

Own brains, Haberman Section 35.

Thu, Feb 3, 05

6


Regular non-negative matrices. Perron-Frobenius theorems. Dominant eigenvalue, stable age distributions.

JR lecture. Haberman Ex 35.2.

Tue, Feb 8, 05

7


Further discussion of discrete-time age-structured models. Deterministic vs. random or stochastic models. Basics of probability. Modelling radioactive decay.

JR Probability pdf

Thu, Feb 10, 05

8

HW2

Comments about Exam #1. Distribution of wait-times in radioactive decay. Generating random numbers with a specified distribution.

JR Probability pdf

Tue, Feb 15, 05

9


EXAM#1


Thu, Feb 17, 05

10


Evolution of ensemble mean and variance in radioactive decay. Large-numbers limits.

JR&KK: Text 1d

Tue, Feb 22, 05

11

HW3

SIR model of epidemic: deterministic and stochastic versions, and their comparison.

JR&KK: Text 1d

Thu, Feb 24, 05

12


Small-group development of better epidemic models.

Own intuition and experience.

Tue, Mar 1, 05

13


Basics of heat transfer, and derivation of the heat equation.

JR: Text 2a

Thu, Mar 3, 05

14

HW4

Heat equation in 1D, simplest steady state solution. Diffusion, diffusion of perfume experiment. Fundamental plane source solution: spreading gaussian.


Tue, Mar 8, 05

15


Time to max temp in briefly heated rod. Method of images for finite slab. Hottest day of the year.


Thu, Mar 10, 05

16


Chemistry. Principle of mass action as a truncated Taylor (MacLaurin) series.

JR: Text 3a

Tue, Mar 22, 05

17

HW5

Exam #2 review.


Thu, Mar 24, 05

18


EXAM#2


Tue, Mar 29, 05

19


ODEs of chemical dynamics. Equilibrium, bistability in Shlogl model. Brusselator.


Thu, Mar 31, 05

20


Brusselator, uniform steady state, small perturbations of USS, linearizing, linear stability analysis, Fourier synthesis.


Tue, Apr 5, 05

21

HW6

Linear stability analysis of brusselator (real roots case): stability boundary in parameter space. Numerical corroboration (java applet).


Thu, Apr 7, 05

22


Numerical methods for reaction-diffusion PDEs: finite difference approximations to 1st & 2nd derivatives, Euler's method.


Tue, Apr 12, 05

23


Qualitative analysis of roots of w^2 + Gamma w + Delta, root types in the n,B plane of Brusselator. Pure modes of the linearized model: animations for various kinds of real and complex w, and mode combinations. Group work: finite difference formulas for derivatives.


Thu, Apr 14, 05

24

HW7

Gray-Scott model: Pearson's experiment. Stripes in nature. Group activity: Euler finite difference solution of heat equation.


Tue, Apr 19, 05

25


Euler finite-difference solution of 2D heat equation as automaton. Conway's 23/3 cellular automaton. Waves: wave equation.


Thu, Apr 21, 05

26

HW8

Excitable dynamics.


Tue, Apr 26, 05

27


Review of semester, and of exam material.


Thu, Apr 28, 05

28


EXAM#3