MET 5810 Applied Optimization

 Instructor:    Mark French

                        138 Knoy Hall

                         desk:          765-494-7521

                         mobile:      765-714-9382

                         e-mail:  rmfrench@purdue.edu

Syllabus:

  Date

Topic

Homework (10 pts/problem)

Due

Assignments are due by 4:30 on the day listed at the homework drop box in Knoy Hall

1/8

Intro to optimization

 

Sample 1-D Functions

 

Monte-Carlo Method

Lifeguard problem

HW #1:

1 - Solve lifeguard problem using Monte-Carlo method and Mathcad

2 – Find Minimum of Example Function 1 using Monte Carlo

3 – Find Minimum of Example Function 2 Using Monte Carlo

 

Since this homework set has already been handed in, here’s the answer key.

1/15

1/10

Binary Search

 

 

HW #2: 

1 - Solve lifeguard problem using binary search

Stop when the change in either the objective function or the estimate of x* is less than 1%.

2 – Solve lifeguard problem using successive parabolic approximations.  X0=0, dx=10.  Stop when the change in approximate solutions is less than 0.25 feet or 8 iterations, whichever comes first.

1/17

 

 

Lifeguard problem using parabolic approximations

1/15

Successive Parabolic Approximations

 

Exit Criteria

 

Solving Simultaneous Equations on a TI-89

 

Solving Matrix Equations on a TI-89

 

Tutorial on Solving Simultaneous Equations

 HW #3:

1 – Solve snap-through spring problem graphically using Mathcad.  Report both local and global minima.

2 – Solve snap-through spring problem using successive parabolic approximation, x0=0, dx=0.5.  Stop when the change in x between iterations is less than 1% or 5 iterations, whichever comes first.

3 – Solve snap through problem when x0=3 and dx=0.5.  Use exit criteria from problem 2

4 – What happens when x0=1 and dx=0.5?

1/22

 

Snap through spring problem

1/17

 

Snap-Through Spring problem statement

Snap-Through Spring Solution

 

Physical Problems:

o      Snell’s Law of Refraction

o      Two-Bar Truss Problem

o      Weight on a Spring

o      Maximizing Range of a Projectile

HW #4:

1 – Find the path through an equilateral glass prism using Snell’s law of refraction

2 – Find the path through the prism by minimizing the optical path length (η=3/2).  Use the method of your choice

 

Description of Prism Problem

1/24

Prism problem

1/22

Local vs. Global Minima

Marching Grid: 2-D analogy to binary search

 

Two Variable Monte Carlo Example

 

Marching Grid Example

HW #5:

1 – Solve the bungee problem using the Monte Carlo method.  Use 25 random number pairs.

2 – Solve the bungee problem using the marching grid method.  Use dx=dy=1 to start.  Stop when the change in x and y is less than 10%.

1/31

(turn hw in at the end of the class period)

Bungee problem – analytical solution

 

1/24

Bungee Jump Problem using 2-D Marching Grid

 

 

1/29

Exam 1 Review

 

1-D Review Problems  Note: this PDF contains solutions using derivatives.  We haven’t gone over this yet in class and derivatives won’t be on the exam.

 

Two variable gradient example

 

1/31

Exam 1

 

Spring 2007 Exam 1

Spring 2007 Exam 1 Answer Key

 

Spring 2008 Exam 1

Spring 2008 Exam 1 Answer Key

 

In-Class, Open Notes, Bring Your Calculator

 

Two variable unconstrained study problem

2/5

No Class

 

 

2/7

No Class

 

 

2/12

Sample 2-D functions

Constrained Optimization Problems

Constrained Lifeguard Problem

HW #6:

 

Structural optimization problem with a single constraint

 

1 – Use Monte Carlo method with 50 different combinations of x1 and x2

 

2 – Use marching grid.  Pick starting points x1 = 0 and x2 = 0.5 inch.  Select your own grid size.  Stop when reducing the step size decreases the volume of the structure by less than 5%.

 

For both problems, create a pseudo-objective function to transform the constrained problem into an unconstrained problem.  Remember that wall thickness has to be positive.

2/19

 

Constrained 2-D problem using solve block

2/14

Maximizing Volume of a Box

Exterior Penalty Function

Heaviside Step Function

 

 

2/19

 

 

2/21

Addition of a buckling constraint

HW #7 Repeat the problem in HW #6 with the addition of an Euler buckling constraint (K=1).  Assume an outer tube diameter of 2 inches rather than 3 inches.

2/28

2/26

Addition of third design variable

Derivatives and Gradients

Gradient Example

 

HW #8 Repeat the two bar truss problem from HW #7, but allow the two wall thickness to very independently.  The three design variables are:  joint location, thickness of tube 1 and thickness of tube 2

 

3/7

2/28

Steepest descent method for unconstrained minimization

 

 

3/4

No Class

 

 

3/6

No Class

 

 

3/11

Spring Break

 

 

3/13

Spring Break

 

 

3/18

 

 

 

3/20

 

 

 

3/25

 

 

 

3/27

 

 

 

4/8

 

 

 

4/10

 

 

 

4/15

 

 

 

4/17

 

 

 

4/22

 

 

 

4/24

 

 

 

 

 

Links:

Wikipedia Article on Optimization

e-optimization community

Wikipedia Article Least Squares Curve Fits

Wikipedia Article on Steepest Descent (Gradient Descent)

 

Grading

Homework                 15%

Exam 1                      25%

Exam 2                      25%

Project                        35%

 

Extra Credit:  As with my other classes.  Bring in some example from the real world and successfully connect it with the topics from the class.  Each demonstration will add two points to your final course average.  Each student may do two demonstrations during the semester.