|
Lectures
|
Date
|
Subjects Covered
|
Lecture Contents/Supplementary Materials
|
|
Last Lecture 36
|
Mon Apr. 4
|
Outline/Summary of Course
|
-
Announcements:
-
Topics Covered in Course:
(The list of topics covered is given in detail in the lecture
outlines below. We present a quick ouline here - in reverse order.
We include a few suggested exercises.)
-
Nonlinear Optimization: Geometry of optimization problems; convex
functions and sets; optimality (KKT) conditions
Exercises in class notes starting page 140, e.g.: 9.1-1),10); 9.2-5);
9.3-2); 9.6; 9.8
- Dynamic Programming: principle of optimality; stages and states;
shortest path problems; investment problems
-
Network Flows: modelling as LP/AMPL; max-flow problem and the F-F
algorithm.
-
Integer Programming: formulations; logical constraints; LP relaxations;
convex hull; branch-and-bound; valid inequalities; cutting planes
(Gomory/Chvatal)
-
Robust optimization: Soyster and Bertsimas-Sim model
See problems in class notes.
-
LP; primal and dual simplex methods; Sensitivity Analysis
See problems in class notes.
|
|
Week 12, Lecture 33-35
|
Mon-Fri Mar. 28-Apr. 1
|
Dynamic Programming; Nonlinear Programming; Integer Programming
|
|
|
Week 11, Lecture 30-32
|
Mon-Fri Mar. 21-25
|
Network Flows
|
-
Announcements:
-
The Network Flow problem on assignment 5 has been modified, i.e. please
use dynamic programming instead of the Ford-Fulkerson algorithm.
-
It is the students' responsibility to ensure that groups have 3 members.
Marks will be deducted if you do not attempt to get 3 members in each
group.
-
April 2011 Math. Awareness Month - complex systems
-
Topics:
-
Network Flows/Models: examples are shortest path problems
(with Dijkstra's dynamic programming algorithm),
max-flow problems
(including special cases assignment and transportation problems)
|
|
Week 10, Lecture 28-29
|
Wed-Fri Mar. 16-18
|
Solving Integer Programs
(
IP Strong Formulations/cutting planes
)
Network Flows
|
-
Announcements:
-
It is the students' responsibility to ensure that groups have 3 members.
Marks will be deducted if you do not attempt to get 3 members in each
group.
-
The projects have been marked; see the Projects link for the marks file.
-
Topics:
-
Cutting Plane Methods (Chvatal-Gomory Cuts; Gomory Cuts)
with example
-
Network Flows/Models: three examples.
|
|
Week 10, Lecture 27
|
Mar. 14
|
Solving Integer Programs
(
branch-and-bound;
IP Strong Formulations/cutting planes
)
Network Flows
|
Topics:
-
Branch & Bound Methods summary/review (dual simplex method!)
(fathom using: infeasibility; bounds; feasibility)
Cutting Plane Methods (Chvatal-Gomory Cuts; Gomory Cuts)
with example
Network Flows
|
|
Week 9, Lecture 24-26
|
Mar. 7-11
|
Branch & Bound Methods;
cutting planes
|
-
solution to assign 3 is available - see Assignments link
-
Branch & Bound Methods
(fathom using: infeasibility; bounds; feasibility)
Cutting Plane Methods (Chvatal-Gomory Cuts; Gomory Cuts)
-
Clarification of bonus question on Assignment 4.
|
|
Week 8, Lecture 23
|
Mar. 4
|
Integer Programming
(
IP Strong Formulations)
comparing formulations)
|
-
Announcements:
- Topics
-
Set Covering/Partitioning:
-
Cutting Stock Problem and Knapsack Problem
Branch and Bound for Knapsack Problem
pdf file
(
useful AMPL link)
|
|
Week 8, Lecture 22
|
Wed. Mar. 2
|
Integer Programming
(
IP Strong Formulations)
|
|
|
Week 8, Lecture 21
|
Mon. Feb. 28
|
Integer Programming
(
IP Strong Formulations)
|
-
Announcements:
- Topics:
-
blood allocation problem (pdf file)
(integer constraints);
blood3.mod;
blood3.dat
There are some useful internal variables in AMPL:
_var is a vector containing the values of all variables;
_varname is a vector containing the names of all variables;
ampl: display _varname; ampl: display _var;
-
AMPL text Section 20.2, Zero-one variables and logical
conditions:
|
|
Week 7, Lecture 20
|
Fri. Feb. 18
|
IP Strong Formulations
|
-
Announcements: Assignment 3 is ready.
|
|
Week 7, Lecture 19
|
Wed. Feb. 16
|
Integer Programming-piecewise linear functions
|
-
Announcements: Assignment 3 is ready.
-
summary of formulation of integer programs:
contingency; multiple choice; logical (big-M); alternatives;
conditional; k-fold alternatives; compound alternatives
-
Facility Location
AMPL files considered:
kilroy.mod;
kilroy.dat;
runkilroy.
-
Modeling piecewise linear functions
|
|
Week 7, Lecture 18
|
Mon. Feb. 14
|
Integer Programming -Modeling
|
pure IP; cardinality constraints; forcing/implication/exlusion; fixed
charge; either/or; ...
AMPL files considered:
gandhi.mod;
gandhi.dat;
rungandhi;
gandhi.txt.
|
|
Week 6, Lecture 17
|
Fri. Feb. 11
|
Robust Optimization
|
-
Announcements:
-
When using AMPL on third floor, the path now has AMPL in it as a default.
Please check the size of problems you can solve. Also, quadratic
problems do not work on the third floor. Therefore, use
NEOS Solvers if needed.
-
Decision making under uncertainty; Bertsimas-Sims model.
See the files:
BerSRobustFarmer.mod;
BerSRobustFarmer.dat;
runBerSRobustFarmer
|
|
Week 6; Lecture 16
|
Wed. Feb. 9
|
Robust Optimization
|
-
Announcements:
-
Midterm exam 4:30-6PM Fri. Feb 18, MC1085; will cover the first
four
chapters of the Course Notes; and it will cover the
AMPL material used in e.g. the homework.
(INFORM instructor if there is a scheduling conflict; covers all of the
first four chapters)
-
Decision making under uncertainty; Soyster's model;
SoyRobustFarmer.mod,
SoyRobustFarmer.dat,
runSoyRobustFarmer
|
|
Week 6; Lecture 15
|
Mon. Feb. 7
|
Modelling Uncertainty
|
-
Announcements:
-
Midterm exam 4:30-6PM Fri. Feb 18, MC1085
(INFORM instructor if there is a scheduling conflict; covers all of the
first four chapters)
-
Braess paradox
also
wiki page
-
Decision making under uncertainty:
facility location 2-stage stochastic optimization with recourse; and
robust optimization;
the farmer's problem
|
|
Week 5; Lecture 14
|
Fri. Feb. 4
|
Modelling Uncertainty
|
|
|
Week 5; Lecture 13
|
Wed. Feb. 2
|
Sensitivity Analysis; Parametric Programming
|
-
Announcements:
-
Please start on getting the data for the project.
See the
Projects link at the top.
-
Review of sensitivity analysis (using revised simplex method), cont...
MATLAB files:
feb2.m,
logfeb2.txt,
|
|
|
|
Sensitivity Analysis via AMPL
|
|
|
|
|
parametric programming
|
parametric programming outline
|
|
Week 5; Lecture 12
|
Mon. Jan. 31
|
Sensitivity Analysis; Dual Simplex Method; Parametric Programming
|
|
|
Week 4; Lecture 11
|
Fri. Jan. 28
|
Sensitivity Analysis cont...
|
-
Announcements:
-
Please start on getting the data for the project.
See the
Projects link at the top.
-
Review of sensitivity analysis using the Revised Simplex Method:
adding a new product, pricing out a new product; changes in objective function
coefficients
|
|
Week 4; Lecture 10
|
Wed. Jan. 26
|
Sensitivity Analysis
|
-
Announcements:
-
A preliminary outline of the project is available at the project list.
-
Reminder: Please send in your list of project groups. Try and meet at
the end of class if you do not have a group yet.
-
manual of how to use gurobi with ampl
(option gurobi_option)
-
Try
NEOS Sovers, e.g. LP with the MOSEK solver (and e.g. diet problem),
or NLP with LOQO
-
Review of sensitivity analysis
|
|
Week 4; Lecture 9
|
Mon. Jan. 24
|
Simplex Method cont...
|
-
Announcements:
-
Assignment 2 is ready.
-
Assignments are
due in class before start of class 9:30-&epsilon AM, or under the door
MC6065 by midnight-&epsilon before the due date; late assignments are not accepted
-
Review of the (revised) simplex method (with an economic
interpretation): shadow prices; changes in the data
(additional reference - paper by Ward/Wendell
|
|
|
|
Modelling with AMPL (sets before variables)
|
In modelling, we see that it helps to find the sets before the
decision variables, e.g. for (a simplified version of)
problem 3 in assignment 1:
ass1p3.mod;
ass1p3.dat.
|
|
Week 3; Lecture 8
|
Fri. Jan. 21
|
(Revised) Simplex Method
|
-
Announcements:
-
Assignments are
due in class before start of class 9:30-&epsilon AM, or under the door
MC6065 by midnight-&epsilon before the due date; late assignments are not accepted)
-
Please form groups for the projects. Please give the instructor the names
in class or by email.
-
The book:
Title: AMPL: A modeling language for mathematical programming.
Call Number: QA402.5 .f688 2003
is on reserve in Davis Centre library.
-
Midterm Exam, Feb.18 Fri:
4:30 - 6:00pm, MC 1085
(make-up 6:00-7:30pm; room announced in person;
ONLY those that INFORM the instructor can take the make-up exam.)
-
Minimum Cost Flow Problem
-
Review/example of the (revised) simplex method
(with an economic interpretation).
|
|
Week 3; Lecture 7
|
Wed. Jan. 19
|
LP Formulations (and AMPL)
|
-
for the third floor machines, please use
the AMPL command: option solver gurobi_ampl;
since the cplex solver is not installed.
See the AMPL FAQ for more details.
-
Multiple time periods, Section 2.4:
steelT.mod;
steelT.dat;
model steelT.mod; data steelT.dat;
solve; display Make; display Inv; display Sell;
-
Scheduling, Section 2.5 in the notes.
(airline crew scheduling, text Chap 12.2 (set partitioning with column
generation using knapsack problem.)
-
Modeling problems with piecewise linear functions, and with
absolute values, e.g. minimize |x|.
(Section 2.5 in the notes, Chapter 14.2 in text)
|
|
|
|
Duality
(Revised) Simplex Method
|
duals of different types of LP models
Review of the simplex method (with an economic interpretation).
|
|
|
|
Sensitivity Analysis via AMPL
|
AMPL data file: gtc-resconst.dat.
Model is resconstr.mod.
Transcript of AMPL session gtc.log.
A listing of sensitivity-analysis and some other useful AMPL commands:
ampl-cmd.txt.
See also:
Some Hints for Getting More from AMPL and CPLEX, including
list of all the cplex options available in AMPL;
The CPLEX distribution of AMPL examples can be found here.
|
|
Week 3; Lecture 6
|
Mon. Jan. 17
|
LP Formulations;
Duality in LP
|
-
(continued from lecture 4)
-
Multiple Period Problem (Investing)
-
LP Review - Duality
Derivation of the linear programming dual for different forms of LP
done using a game theory approach; including an economic
interpretation. (The diet problem was used to illustrate the approach.)
|
|
Week 2; Lecture 4-5
|
Fri. Jan. 14
|
LP Formulations (and AMPL)
|
multiple sets again:
(From AMPL-a tutorial [pdf- pgs 7-11]
|
|
Week 2; Lecture 3
|
Mon. Jan. 10
|
Software (AMPL/Solvers) cont...
|
-
(official) AMPL FAQ;
Intro. to AMPL-a tutorial
[pdf-13 pgs]
(also:
online documentation from
AML page; and a
local copy pdf file - 17pgs)
-
(change path to use AMPL
and a better way is to use a file similar to:
newpath.cmd)
enter the lines from
examp1.mod from assignment 1.
Enter the AMPL commands:
show;
expand;
solve;
display x1, x2, x3, x4, x5, x6, x7, x8;
display Expense;
display T1, T2, T3, T4;
display x1.rc, x2.rc, x3.rc, x4.rc, x5.rc, x6.rc, x7.rc, x8.rc;
-
blending example mod file from Sect 2.2
and the
blending example dat file from Sect 2.2.
-
Four different ways of entering a (elementary) LP:
-
paint.mod;
-
paint2.mod;
paint2.dat;
-
paint2alt.dat;
-
paintset.mod;
paintset.dat;
paintsetalt.dat;
-
A
list of AMPL commands used during the lecture.
-
A listing of sensitivity-analysis and some other useful AMPL commands:
ampl-cmd.txt.
|
|
Week 1; Lecture 2
|
Fri. Jan. 7
|
Building Math. Models
|
- Two models from Course Notes, Chapter 2, Pages 9-12:
Resource Constraint
Problem; Blending Problem.
- Emphasizing
sets
during three steps of finding:
- Decision Variables
- Objective Function
- Constraints
|
|
Week 1; Lecture 1
|
Wed. Jan. 5
|
Introduction/Administrivia/LP-review
|
|