IllStateCP_davidson - Department of Physics | Oregon State

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Computational Course Projects and Undergraduate Research

B. K. Clark and Richard F. Martin, Jr.

Illinois State University

Contributors:

E. Rosa

D. Holland

R. Balfanz

N. Jurasek

Q. Su

R. Grobe

N. Nutter

B. Vleck

Resources: ISU Physics and its Peers

2004 - 2006

Institution # of faculty publications % of faculty average grant % of faculty per faculty with publication amount with grant

Top 10 68 6.62 64 % $ 569 K 11 %

ISU Physics 12 4.83 83 % $ 92 K 17 %

Top 10 Physics departments

Cal Tech, Harvard, Cornell, JHU, UC

Berkeley, NYU, Michigan, Duke, Stanford,

UIUC

From:

“Chronicle of Higher Education” 1/12/2007 www.chronicle.com/stats/productivity

Undergraduate physics research at ISU

Nonlinear Dynamics

Nanoscience

Space Physics

Atomic, Molecular, and Optical Physics

Biophysics

Annual Average Number of

Graduates 2002-2004

United States Air Force Academy 24

Harvey Mudd College 22

U. of Wisconsin – La Crosse 22

Illinois State University 20

Source: American Institute of Physics

CPY: Computer physics

PTE: Physics

Teaching

PHY: Physics

ENG: 3/2 program

ISU Computer Physics Sequence

1998-2007

Total graduates 35

Graduates per year 4

Computation Research Mentors 9

Advanced Computational Physics

Modules 7 (3 per year)

Number of physics graduates from 1980 to present

30

25

20

15

10

5

0

198019811982198319841985 19861987198819891990 199119921993199419951996 19971998199920002001 200220032004200520062007

CPY

PTE

ENG

PHY

Computer Physics Curriculum

Frontiers in Physics

Physics for Scientists and Engineers I

Physics for Scientists and Engineers II

Physics for Scientists and Engineers III

Methods of Theoretical Physics

Mechanics I

Electricity and Magnetism I

Experimental Physics

Quantum Mechanics I

Thermal Physics

At least one from:

PHY 320 Mechanics II

PHY 340 Electricity and Magnetism II

PHY 384 Quantum Mechanics II

Elective Courses

One additional 300-level Physics course.

Recommended Electives

Nonlinear Science

Molecular Dynamics Simulations

Methods of Computational Science

Advanced Computational Physics

Computational Research in Physics

Computer Science Courses

Programming for Scientists

Hardware and Software Concepts

Computer skills and techniques

Techniques introduced in the core for both computer physics and physics majors

2D graphics: 6-8

Mathematica: 2-3

Function Evaluation: 2+

Data analysis/curve fitting: 3

ODE – Euler, 2

ODE – 2 nd Order Methods: 3

Monte Carlo (simple): 4

ODE – 4 th order Runge-Kutta: 3

Fourier: 4-5

Integration: 1+

Over relaxation: 1-2

Graphical analysis of transcendental equations: 1-2

Molecular Dynamics: 1-3

Phy 320, 340, 384

Complex Analysis: 1

Monte Carlo (variational): 1

Eigenvalues: 2

Molecular Dynamics:1-3

Other elective courses

Surface-of-section: 1

Ray Tracing: 1

Matrix methods: 1

Fractal Dimension: 1

Computer skills and techniques

Methods of Computational Science

ODE – Adaptive/High Order: 1-3

Computational efficiency: 1

Integral equations by matrix inversion: 1

Theory of ODE techniques:1

Advanced Computational Physics

Split operator: 1

Finite element: 1

Neural network: 1

Molecular Dynamics: 1-3

Monte Carlo: 1-4

Students see at least three of these

Computational Research in Physics

Mesh Method for Liouville eqn

Quadratic Programming and optimization

Matrix methods

Cellular Automata

Integral equations by matrix inversion

Neural network

Eigen analysis

Each student has seen one of these in the recent past

Number indicates the number of times a student is likely to encounter a skill or technique. Listings for advanced courses do not include all of the techniques a student has previously encountered.

Observations on computer physics at ISU

Computational physics is on an equal footing with experimental and theoretical physics at ISU. This will probably be the norm in another generation.

When computational techniques were introduced across the program in the late 80’s and early 90’s, faculty teaching each course chose which techniques to include in their respective courses.

Some general discussion occurred in an attempt to make sure that students encountered a broad range of techniques and techniques deemed critical, in particular.

The computer physics sequence started in 1998. Methods of

Computational Science is designed to provide a theoretical framework for computational techniques. Computational Research in Physics evolved from an earlier course and provides students with a mixture of theoretical physics and related cutting edge computational techniques.

The program at ISU focuses on students writing their own computer code.

There are some exceptions. In a few instances a faculty member provides a working code and students must make some changes. The department also uses Mathematica.

Most faculty actively contribute to the integration of computer physics into the curriculum. Some have been encouraged to boost the level of computer physics in core courses.

In informal discussion with 3 rd semester physics students, teacher education students generally prefer less computer physics integration, computer physics students really like it, and traditional physics students fall somewhere in between. By graduation, each student has selected the course of study most appealing to him or her, and each program is responsible for about a quarter of our graduates.

Computer physics and traditional physics students generally agree that computational physics has helped them to more clearly understand equations and systems.

The Computer physics sequence at ISU thrives in part because 75% of faculty classify themselves as computational (at least in part), providing a strong base. All faculty support the program. Computational physics is more financially accessible to under-funded state schools than experimental physics.

Physics 388

Advanced computational physics

Neural networks

Comparison of classical and quantum physics

Bio-optical physics

Finite element analysis

Physics 390

Computational research in physics

Computational study of synchronization of coupled non-linear oscillator systems

Gerrymandering and fractal dimensions of congressional districts

Cellular automaton investigation of the transition from non-flocking to flocking behavior

Central current sheet ion distribution functions

Neural Networks

Interdisciplinary field active since 1940’s

Used regularly in science and engineering for prediction, optimization, data mining, etc.

Pedagogical goals: students will

Understand neural models

Build intuition for selecting net parameters

Reinforce basic timeseries analysis (e.g. power spectrum & autocorrelation function)

Understand when to train with causal inputs

(physics example) vs. self-prediction (financial example)

Write ANN code to do self-prediction with Dow Jones index

See at least one associative or self-organizing network model

Neural Networks

Scientific ANN example: the Auroral Electrojet (AE) Index

Fast decorrelation time so use causal inputs

Train with several different sets of input data to determine which sets allow best prediction

Example: Single hidden layer net, using backpropagation

[Gleisner & Lundstedt. 1997]

Go over network design choices

Results consistent with years of data analysis

Neural Networks

ANN Topics

Biological NNs, learning theory

Neuron models, training, limitations

Learning rules: Hebb, Delta, Backpropagation

Net design: theorems, rules of thumb, testing

Predictability of timeseries

Backpropagation for timeseries (AE and financial)

Hopfield nets: character recognition Predict Dow Jones

Train with 200 months

Predict for 300 months

Written Assignments

Basic neuron models

Linear separability

Programs

Single neuron for NOR

Delta rule for XOR

Backpropagation for time series, DJIA

Comparison of Classical and Quantum Physics

(based on research program of R. Grobe and Q. Su)

Classical and quantum physics are employed to describe many phenomena. Understanding their range of applicability is important in developing students physics intuition

Pedagogical goals: students will

Simulate non-interacting classical ensembles with a Monte Carlo technique

Use non-uniformly distributed random numbers, Box-Muller algorithm, rejection method, and Fast Fourier transformation

Use Split-operator techniques

Create an NCAR graphics animation inputs (physics example) vs. self-prediction (financial example)

Comparison of Classical and Quantum Physics

Students calculate spreading of a classical ensemble of particles and wave function that describes the equivalent quantum mechanical picture. The particles experience a constant (linear) force.

Classical results: particle distribution in phase space at three times

Quantum results: wave function at three times

Comparison of Classical and Quantum Physics

Topics in Classical and Quantum Topics

Distribution functions, average values, higher moments

The Liouville equation, multi-particle simulations

The Schrödinger equation, exploiting linearity, decomposition into advantageous states

Free-time evolution using FFT

Second and Third order split-operator scheme with error estimates

Written Assignments

Calculate moments of a swarm of bees

Liouville equation and the conservation of the norm of r

Programs

Evolution of a classical distribution of particles

Evolution of a quantum mechanical wave packet

Bio-Optical Physics

(based on research program of Q. Su and R. Grobe)

One of the youngest fields and expected to play a significant role in the “century of life sciences”

Non-invasive optical diagnostic techniques are expected to have great impact on the economics of medicine and help provide early detection of cancers

Pedagogical goals: students will

Understand the physics of x-ray and IR imaging

Understand the micro- and macroscopic pictures of light/matter interactions

Apply the Boltzmann equation to light scattering using Monte

Carlo techniques

Model the propagation of light through a turbid medium

Bio-Optical Physics

Transmission and reflection of modulated beam

Beam spread for constant intensity Beam spread for modulated intensity

Bio-Optical Physics

Topics in bio-optical physics

Introduction to bio-optical physics

A matrix model of X-ray image reconstruction

Micro- and macro-scopic views of light-tissue interactions

The Boltzmann equation (BE) for light

The scattering phase functions

A bi-directional model of light scattering

A Monte-Carlo algorithm to solve the BE

The photon density waves

The diffusion approximation

Imaging with mirrors

Written Assignments

X-ray shadow gram absorption coefficients

1-D diffusion equation

Programs

1-D Boltzmann equation via a Monte-Carlo algorithm

Photon density waves with constant and periodic time dependence

Finite Element Analysis

Powerful numerical method for solving problems in physics and engineering such as: fluid flow, heat transport, structural mechanics (torsion, elasticity, etc.)

Frequently used in engineering for modeling problems such as the structural framework of automobiles and aircraft, groundwater flow, and heat flow.

Easily generalized to handle 1D, 2D and 3D problems with complicated boundaries, sources, sinks, and multiple materials.

Finite Element Analysis

Pedagogical goals: students will

Understand the theoretical basis for the finite element method, i.e. minimization of a functional on a grid. (Calculus of Variations.)

Understand how to set up the element grid in 1 and 2 dimensions.

Write a 1-D finite element code for calculating the temperature in a fin with various boundary conditions (e.g. insulated/non insulated) and with varying materials.

Topics in Finite Element Analysis

Fundamental concepts

Nodes, elements, shape functions

Calculus of variations

Functionals

Heat transfer

Embedding equations

Finite Element Analysis

Written Assignments

Calculate various shape functions

Determine single element equation matrices

Determine embedding equations

Programs

Solve 1-D heat transfer along a fin (circular rod)

Example results for a 1-D uninsulated rod of radius 1cm and length 10 cm. The ambient air temperature is 30

C and the thermal conductivity of the material is

75 W/cm-

C. There is a continuous heat input of 450

W/cm 2 on the left end of the rod. Calculation in done using 10 elements.

Computational Study of Synchronization of

Coupled Non-Linear Oscillator Systems

(a component of E. Rosa research program)

Student: Brian Vlcek Advisor: E. Rosa

Chua Circuit and Chaotic

Attractors dx/dt = (G(x

2

-x

1

)-y(x

1

))/C

1 dy/dt = (G(x

1

-x

2

)-x

3

)/C

2 dz/dt = -x

2

/L

G = 1/R

Phase difference: Δ j

12

= j

1

j

2

Computational Simulation: Chua Circuit Power

Spectra

ε

12

= ε

13

= 0.0

fast medium slow

ε

12

= 0.055 ε

13

= 0.010

Neural Action Potential Simulation

Hodgkin-Huxley Neural Spiking Model

ε

12

= ε

13

= 0.0

ε

12

= ε

13

= 0.01

Gerrymandering and Fractal Dimensions of

Congressional Districts

Student: Nicholas Jurasek Advisors: B. Clark, D. Holland

Written in C++

Uses SDL image library for image manipulations

It has a very easy to use point and click interface.

Very fast, can calculate the fractal dimension in seconds.

Chicago Congressional Districts

Box Counting Algorithm

The program loads in a BMP image, then displays it on the screen.

The user then clicks on the boarder Color.

A district color is then selected.

The program then breaks the image into boxes and looks in each box to see if it contains both the border color and the district color.

If a box meets both conditions it is on the perimeter of the district, and it is counted.

The number of boxes is then plotted against the box dimension.

The boxes are then decreased in size by a factor of 2 and the process is repeated.

After several iterations the slope of the emerging line is calculated and this becomes the fractal dimension.

Resulting Fractal Dimensions

Ln(S)

0

.693147

1.38629

2.07944

2.77259

Ln(N)

0

0

1.38629

2.19722

3.17805

3.5

3

2.5

2

1.5

1

0.5

0

0

Von Koch Snowflake y = 1.2925x - 0.4338

1

Ln(S)

2 3

Cellular automaton based investigation of the transition from non-flocking to flocking behavior

Student: Ryan Balfanz Advisors: D. Holland, B. Clark

Flocking can be simulated from a few simple “microscopic” rules (Reynolds)

W

1

W

2

, Flock Centering: head to the center of the other boids

, Collision Avoidance: don’t fly into other boids

W

3

, Velocity Matching: approach the average velocity of the other boids

By applying the rules to each boid, a macroscopic behavior emerges

What causes the transition between non-flocking and flocking motion?

W

1

0

1

10

10

10

Typical behavior encountered for 16 boids

W

2

0

1

100

100

100

W

3

-1

1

0

0

1

Observed Behavior

No Organization

Bird Flocking

Vortex

Fish

Swarm v final v initial v

1

* w

1 v

3

* w

3 v

2

* w

2

No Organization Bird Flocking

Typical behavior encountered for 16 boids

Vortex Fish

Swarm v final v initial v

1

* w

1 v

3

* w

3 v

2

* w

2

Central current sheet ion distribution functions

(a component of D. Holland research program)

Student: Nathan Nutter Advisor: D. Holland

Ions interacting with the magnetotail have complicated trajectories resulting in a relative redistribution of particles as compared to their incident distribution.

Transient Orbit

-50.0

-40.0

-30.0

-20.0

x

-10.0

0.0

10.0

6.0

-1.0

0.0

1.0

4.0

2.0

3.0

4.0

5.0

-6.0

-8.0

6.0

y

2.0

0.0

-2.0

z

-4.0

Integrable Orbit

-0.2

0.0

0.2

0.4

0.6

x 0.8

1.0

1.2

-1.0

-0.5

0.0

y

0.5

1.5

1.0

0.5

0.0

z

-0.5

-1.0

-1.5

1.0

Chaotic Orbit

-50.0

-40.0

-30.0

-20.0

-10.0

x 0.0

10.0

6.0

4.0

2.0

-3.0

-2.0

-1.0

0.0

1.0

y

2.0

3.0

-6.0

-8.0

4.0

0.0

-2.0

z

-4.0

Current sheet algorithm

Use a test particle code to push a distribution of particles through a model magnetic field.

Each particle should contribute equal phase space “weight” in the uniform magnetic field region.

Create single particle distribution by putting the particle in its proper energy/pitch angle/z-position bin at each time step. f i

(H,

,z)

Divide the single particle distribution by the total number of “counts” in the top grid cell so that each particle contributes unit density to the total distribution.

Sum the single particle distributions to get an overall distribution.

f tot

( H ,

, z )

 i

N 

1 f i

( H ,

, z )

Typical results for current sheet

Since individual particles are non-interacting, this is an ideal problem for parallel processing.

(xgrid)

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