Homepage for MAS275


February-2009


Syllabus and course information.

Please come see me if you have any questions.

Office Hours: Tuesday and Thursday 4 pm - 6pm.

If these times are not convenient just make an appointment by email or phone!

office: E6-1 4411

email: andreash[at]kaist.edu

tlf: (+82) 42 350 7300


Solutions for final exam.

Scorelist for final exam.

CLAIMS for final exam grades will be May 26 -- 28. You can pick up your exam in my office.


Here you can download last years final exam.

Here is solution to homework 3.


Office hours before FINALS

I am available for office hours before the finals on Friday, Tuesday and Wednesday! These will take place in the Common Room on the 1st floor of the math department (bldg E6-1). Otherwise, Please email for appointment.

Suggested problems before FINALS

I suggest to try all problems from the textbook, but there are some of them that touch topics we did not cover in class. Here are the ones to focus on:

Chapter 9: 2 -- 6, 9 -- 18, 21, 23 -- 29, 31 -- 40, 41.

Chapter 10: 1 -- 4, 9, 10, 11, 15 -- 18, 21 -- 25, 27 -- 31, 33, 34, 35, 38.

Chapter 11: 1 -- 4, 8, 9, 12, 13, 15, 16, 18, 19, 24, 25, 26, (27, 28).

Chapter 12: 1 -- 16, 19, 20.

Chapter 13: 1, 2, 5, 6, 7, 15 -- 32.


FINALS: important notice

The final exam in MAS275 is scheduled for MAY 20th, 2010 (Thursday). Time: 14:30 ~ 17:30. Place: E6-1, room 3435 and 3433.

Topics that will be covered on the test are Chapters 9 -- 13.


Midterms: important notice

The midterm in MAS275 is scheduled for MARCH 25th, 2010 (Thursday). Time: 14:30 ~ 17:30. Place: E6-1, room 3435. The midterm exam will cover Chapters 1.1, 1.2, 2.1, 2.2, 3.1, 3.2, 3.3, 4.1, 4.2, 5.1, 5.2, 5.3, 7.1, 7.2, 8.1 from Bóna's book, as well as what was covered in the homeworks.

Download the midterm.

Download the solution. (beware of typos!)

Midterms: Claims.

Claims session will be held Friday 04/02 between 1pm and 2pm in my office (4411). Next claim sessions will be Monday 9-10pm and Tuesday 10-11pm, room 3430.


Homework

Homeworks are to be submitted in the box labeled MAS275 outside office 3427, E6-1.

First Homework assignment (Posted: 2010/02/18. Due: 2010/02/26).

Second Homework assignment (Posted: 2010/03/04. Due: 2010/03/12). Solution

Third Homework assignment (Posted: 2010/04/09. Due: 2010/04/16). (two pages)


Progress

2010/02/02 : We covered chapter 1 on pigeon-hole principle with applications from number theory, graph theory, and geometry.

2010/02/04 : We covered chapter 2 on mathematical induction, and presented the solution to the problem from previous class, due to 박진강.

2010/02/09 : We covered chapter 3 on elementary counting problems: permutations, strings over finite alphabets, ordered and unordered selections.

2010/02/11 : We completed chapter 3 on elementary counting problems: Bijections and selection problems. We counted the number of multisets of size k from [n], and non-negative integer solutions to the equation x1+...xn = k.

2010/02/18 : We did chapter 4 on combinatorial identities, the binomial and multinomial theorem. First homework assignment posted online.

2010/02/23 : We started chapter 5, covering compositions and set partitions, stirling numbers and surjective functions f : [n] -> [k]

2010/02/25: We continued with chapter 5, integer partitions, Ferrers shapes and some basic identities involving conjugation.

2010/03/02: We proved Euler's partition theorem: the number of partitions of n into distinct parts equals the number of partitions of n into odd parts. We presented solution to a previous extra credit question.

2010/03/04: We covered cahpter 7 on Inclusion-Exclusion Principle. Computed the number of derangements of [n], the number of surjective functions f:[n]->[k], and the permanent of a square matrix.

2010/03/09: We started chapter 8 on generating functions. We covered basic definitions and some examples of solving recurrence relations using generating functions.

2010/03/11: We continued chapter 8 on generating functions, establishing the product rule and composition of ordinary generating functions, and covered several examples illustrating how to use these rules.

2010/03/30: We introduced some basic notions of graph theory. This included trails, paths, and cycles. Degree sequence and the handshaking lemma. Diameter of a graph.

2010/04/01: We introduced some basic classes of graphs. The empty and complete graph. The complement of a graph. k-partite graphs and the chromatics number. We showed that a graph is bipartite if and only if every cycle is of even length. We showed that a graph with at least as many edges as vertices must contain a cycle, and we used this to prove that a connected graph is Eulerian if and only if every vertex is of even degree.

2010/04/06: We gave an algorithm for finding a Eulerian cycle in a graph. We defined hamiltonian graphs and proved Ore's theorem on hamiltonian cycles.

2010/04.08: We defined forest and trees and studied some basic properties of trees. Cayley's theorem on number of labeled trees on n vertices. Greedy algorithm for finding minimum weight spanning tree in a weighted graph.

2010/04/13: We studied some matrices associated with graphs: the adjacency matrix, the incidence matrix and the Laplacian. Matrix-tree theorem.

2010/04/15: We solved several problems and exercises concerning trees.

2010/04/20: We proved Turan's theorem: for any n there is a unique graph on n vertices and maximal number of edges which does not have a complete Km subgraph.

2010/04/22: We proved Hall's marriage theorem and studied some applications: complete matchings in regular bipartite graphs, latin squares and doubly stochastic matrices.

2010/04/27:

2010/04/29:

2010/05/04:

2010/05/06:

2010/05/11:

2010/05/13:


Suggested problems

You should try to do all the 'Supplementary Exercises' from Bóna's book! The ones selected below will be reviewed during a recitation class.

2010/02/02 : Ch. 1; Pr. 19, 20, 25, 26, 27, 28.

2010/02/04 : Ch. 3; Pr. 29, 30, 35, 43, 48.

2010/02/18 : Ch. 3; Pr. 41, 42. Ch.4; Pr. 31, 34, 50, 51.

2010/03/06 : Ch. 1; 6, 8. Ch. 5; 23, 24, 25. Ch. 7; 15, 21, 23, 26, 27.

2010/04/01 : Ch. 9 ; 2, 3, 4, 5, 10, 11, 12, 16, 25, 29, 32, 35, 39.

2010/04/22 : Ch. 10; Pr. 24, 34, 27, 37. Ch. 11; Pr. 24, 25, 26 , 27, 28.


Recitation

We will have recitation classes where we solve problems from the book. These classes are NOT mandatory. Time and date will be announced in class.

2010/02/11 : Recitation class 7-8pm, room 3435

2010/03/02 : Recitation class 7-8pm, room 3435

2010/03/11 : Recitation class 7-8pm, room 3435