yrd . doç . dr. didem kivanc tureli didemk@ieee [email protected]

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OKAN UNIVERSITY FACULTY OF ENGINEERING AND ARCHITECTURE MATH 256 Probability and Random Processes 01 Introduction Fall 2011 Yrd. Doç. Dr. Didem Kivanc Tureli [email protected] [email protected] 1 06/13/22 Lecture 1

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OKAN UNIVERSIT Y FACULTY OF ENGINEERING AND ARCHITECTURE MATH 256 Probability and Random Processes 01 Introduction Fall 2011. Yrd . Doç . Dr. Didem Kivanc Tureli [email protected] [email protected]. MATH 256: Probability and Random Processes. Instructor: Didem Kıvanç Türeli - PowerPoint PPT Presentation

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Page 1: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

OKAN UNIVERSITYFACULTY OF ENGINEERING AND ARCHITECTURE

MATH 256 Probability and Random Processes

01 IntroductionFall 2011

Yrd. Doç. Dr. Didem Kivanc [email protected]

[email protected]

104/21/23 Lecture 1

Page 2: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

MATH 256: Probability and Random Processes

• Instructor: Didem Kıvanç Türeli• [email protected][email protected]• Phone:?• Office: Engineering & Architecture Building 328• Class: Wednesday 11-12:00, 13:00-15:00 – Room D408• Course website:

http://personals.okan.edu.tr/didem.kivanc/courses/MATH256/

04/21/23 Lecture 1 2

Page 3: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

MATH 256: Probability and Random Processes

• Textbook– A First Course in Probability (8th Edition) by Sheldon Ross, Eighth Edition,

Prentice Hall, ISBN: 013603313X / 0-13-603313-X– Probability, Random Variables and Random Signal Principles (4th Edition)

by Peyton Z. Peebles, Jr., ISBN: 0-07-366007-X / 978-0073660073

• Course Outline– Combinatorial Analysis, Axioms of Probability, Conditional Probability

and Independence, Random Variables, Jointly Distributed Random Variables, Properties of the Expectation Operator, Limit Theorems, Temporal Characteristics of Random Processes, Poisson Processes and Markov Chains.

• Prerequisites– Calculus I,II,III,IV

04/21/23 Lecture 1 3

Page 4: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

EE 403 Grading Policy• Homework: Homework will be mandatory.• Exams: 2 Midterm exams and 1 Final Exam• Attendance: 70% is required.• Quizzes are randomly given at any time of the class.• Grading: The final course grade will be based on

homework, quizzes, midterm exams, and final exam.• Grading Formula:

0.02xQuiz+0.08xHomework+0.4xMidterms+0.5xFinal

04/21/23 Lecture 1 4

Page 5: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Academic Dishonesty

• Any violation of academic integrity will receive academic and possibly disciplinary sanctions. The sanctions include the possible awarding of a F grade.

• Cheating• Copying on a test• Plagiarism• Acts of aiding or abetting• Submitting previous work• Tampering with work• Altering exams

04/21/23 Lecture 1 5

Page 6: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Course Objectives• Upon completing the course, students will be able to analyze

systems which involve random variables.

04/21/23 Lecture 1 6

Page 7: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Course Outline (1/2)

04/21/23 Lecture 1 7

Course Plan

Week 1.(Sep. 21st) Combinatorial AnalysisWeek 2.(Sep. 28th) Axioms of ProbabilityWeek 3.(Oct. 5rd) Conditional Probability and Independence

Week 4.(Oct. 12th) Random Variables

Week 5.(Oct. 19th) Continuous Random Variables Week 6.(Oct. 26th) Midterm 1Week 7.(Nov. 2nd) Jointly Distributed Random Variables

Page 8: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Course Outline (2/2)

04/21/23 Lecture 1 8

Week 8.(Nov. 9th) No Class (Kurban Bayramı)

Week 9.(Nov. 16th) Properties of Expectation

Week 10.(Nov. 23rd) Limit Theorems

Week 11.(Nov. 30th) Midterm Exam-II

Week 12.(Dec. 7th) Temporal Characteristics of Random Processes

Week 13.(Dec. 14th) Temporal Characteristics of Random Processes

Week 14.(Dec. 21st) Poisson Processes and Markov Chains

Final Exam 02/01 - 13/01 2012

Page 9: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Example of how we use probability• Consider a communication system with multiple antennas.

We need at least one antenna working correctly for the system to work.

• Any antenna can fail with probability ½. • What is the probability that the system will fail? (i.e. none of

the antennas will work)

04/21/23 Lecture 1 9

Page 10: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Look at all the possibilities …• Count the number of ways things can occur.

• The mathematical theory of counting is called combinatorial analysis.

04/21/23 Lecture 1 10

Antenna 1 Antenna 2 Antenna 3 Antenna 4 Antenna 5

1 1 1 1 1

1 1 1 1 0

1 1 1 0 1

1 1 1 0 0

1 1 0 1 1

1 1 0 1 0

1 1 0 0 1

Page 11: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

The basic principle of counting• Two experiments are performed. • If experiment 1 can result in any one of m possible outcomes,

and • experiment 2 can result in any one of n possible outcomes,

then • together there are mxn possible outcomes of the two

experiments.

04/21/23 Lecture 1 11

Page 12: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

The generalize basic principle of counting• r experiments– n1 possible outcomes of first experiment

– For each of n1 possible outcomes, n2 possible outcomes of 2nd experiment,

– For each of n2 possible outcomes, n3 possible outcomes of 3rd experiment,

– …• Then there are a total of n1 x n2 x n3 x … x nr possible

outcomes of the r experiments.

04/21/23 Lecture 1 12

Page 13: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Examples• How many 7 place license plates are possible if the first 3

places are to be occupied by letters and the final 4 by numbers?

• (assume 26 letter alphabet)• 26 x 26 x 26 x 10 x 10 x 10 x 10

• What if you don’t allow repetition of letters or numbers?

04/21/23 Lecture 1 13

Page 14: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Permutations• How many different ordered arrangements of the letters a,b,c

are possible?• abc, bac, acb, cab, bca, cba• 3 x 2 x 1 = 6 permutations• Number of permutations of n objects:– n! = n x (n-1) x (n-2) x … x 1

• How many arrangements using the letters PEPPER?

04/21/23 Lecture 1 14

Page 15: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

• Each letter is different: P1, E1, P2, P3, E2, R1

04/21/23 Lecture 1 15

P1 E1 P2 P3 E2 R1 P1 E2 P2 P3 E1 R1 E1 P1 P2 P3 E2 R1 E2 P1 P2 P3 E1 R1

P2 E1 P1 P3 E2 R1 P2 E2 P1 P3 E1 R1 E1 P2 P1 P3 E2 R1 E2 P2 P1 P3 E1 R1

P1 E1 P3 P2 E2 R1 P1 E2 P3 P2 E1 R1 E1 P1 P3 P2 E2 R1 E2 P1 P3 P2 E1 R1

P3 E1 P1 P2 E2 R1 P3 E2 P1 P2 E1 R1 E1 P3 P1 P2 E2 R1 E2 P3 P1 P2 E1 R1

P2 E1 P3 P1 E2 R1 P2 E2 P3 P1 E1 R1 E1 P2 P3 P1 E2 R1 E2 P2 P3 P1 E1 R1

P3 E1 P2 P1 E2 R1 P3 E2 P2 P1 E1 R1 E1 P3 P2 P1 E2 R1 E2 P3 P2 P1 E1 R1

6!Number of permutations

3!2!1!

Number of RsNumber of PsNumber of Es

Page 16: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Number of permutations in general…• If there are n objects, of which n1 are alike, n2 are alike, n3 are

alike, …, nk are alike, then

04/21/23 Lecture 1 16

1 2

!Number of permutations

! ! !k

n

n n n

Page 17: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Combinations• Determine number of different groups of r objects that could

be formed from a total of n objects. • This time there is no order to the objects: abc is the same as

cab.• Example: How many ways are there to choose 3 letters from

the English alphabet (26 letters)?– {a,b,c}, {a,b,d}, {a,b,e}, …– {a,c,b}, {a,c,d}, {a,c,e},…– {a,b,c} is the same as {a,c,b}– How many groups are the same? Or to ask this differently– How many permutations of 3 letters are there? 3!

04/21/23 Lecture 1 17

Page 18: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Combinations• Number of different groups of r items that could be formed

from a set of n items

04/21/23 Lecture 1 18

( 1) ( 1) ( 1) !

! ( )! !

n n n n r n

r n r r

Define for !

( , )( )! !

rnn

C n rr n r r

n

• DEFINITION: The number of possible combinations of n objects taken r at a time

Page 19: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

• Useful identity:

04/21/23 Lecture 1 19

1 11

n n nr r r

• THEOREM: The Binomial Theorem

0

( )n

n k n k

k

nx y x y

k

Page 20: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Multinomial Coefficients• A set of n distinct items is to be divided into r distinct groups

of respective sizes n1, n2, …, nr, where

• How many different divisions are possible?• There are – C(n, n1) possible choices for the first group

– C(n-n1, n2) possible choices for the second group

– C(n - n1 - n2, n3) possible choices for the third group, …

04/21/23 Lecture 1 20

0

.r

ii

n n

Page 21: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

04/21/23 Lecture 1 21

1 1 2 1

1 2

1 1 2 1

1 1 1 2 2

1 2

! !!

! ! ! ! 0! !!

! ! !

r

r

r

r

r

n n n n n nnn n n

n n n n n nn

n n n n n n n nn

n n n

Page 22: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Multinomial Theorem

04/21/23 Lecture 1 22

1 2

1 21 2 1 2

Define for !

( , , , , ), , , ! ! !

r

rr r

n n nnn

C n n n nn n n n n n

n

• DEFINITION:

• THEOREM: The Multinomial Theorem

1 2

1

1

1 2 1 21 2( , , ):

( ), , ,

r

r

r

n n nnr r

rn nn n n

nx x x x x x

n n n

Page 23: Yrd .  Doç . Dr. Didem Kivanc Tureli didemk@ieee didem.kivanc@okan.tr

Distribution of Balls in Urns• x1+

04/21/23 Lecture 1 23