VTU PhD Workshop

VTU PhD Workshop1

Ph.D. in Computer Science:

A Perspective

One Day Workshop: July 2, 2010

Computer Science and Automation

Indian Institute of Science, Bangalore

VTU PhD Workshop2

The Ph.D. Process: Part 1 Thesis Production“PhD in Computer Science: A

Perspective”

One Day Workshop: July 2, 2010

Y. NARAHARI Computer Science and Automation

Indian Institute of Science, Bangalore

THESIS

ADVISOR

INSTITUTION

RESEARCHCOMMUNITY

REAL WORLD

Part IInternal

s(YN)

Part IIExterna

ls(JH)

The PhD Process

VTU Ph.D. Workshop4

OUTLINE

What is Research? ; Basic Vs Applied Research

What is PhD? ; PhD in Computer Science

Examples of PhD Problems

Ingredients of a Good PhD Program

Writing a Ph.D. Thesis

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Inspiration: Richard Hamming

•Pioneering contributions in coding, information theory,Automatic Programming

•Talk entitled “You and Your Research” on March 7, 1986:Bell Communications Research Colloquium Series

•Question: Why do so few scientists make significant contributions and so many are forgotten in the long run?

ACM TURING AWARD 1968

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What is Research?

Carving statues out of stones in a creative way

Systematic investigation to establish facts or discover new facts

Scientific investigation intended to extend the limits of human knowledge

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Richard Hamming’s View

Luck favours a prepared mind

Knowing/asking right questions is the first stepin knowing the answers

If you believe too much, you will not notice the flawsIf you doubt too much, you won’t get started -

You need a lovely balance

Courage to continue working is important

VTU Ph.D. WorkshopSource: Google Images

Basic vs Applied Research

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What is Ph.D.?

Rigorous investigation into an important, non-trivial problem, leading to a new methodology,

novel algorithms, or a significant tool

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Ph.D. in Computer Science

CS has a wide appeal cutting across disciplines;Offers wide scope for inter-disciplinary research

Exciting new areas: machine learning, computational biology, computational economics,

cyber-physical systems, etc.

There is equal scope for basic research,applied research, use-inspired basic research

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PhD Problems: Example 1

Design of optimal auctions for heterogeneous objects

Motivating ProblemsSponsored Search Auctions,

Procurement Auctions, Spectrum Auctions

Intellectual ChallengeOptimal auction available only for single unit of

single object – difficult to generalize


Motivating Problem: Sponsored Search Auction

AdvertisersCPC

1

2

n

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EXTENSION OF MYERSON’S AUCTION

Myerson Auction1 Seller, Multiple Buyers,

Single Indivisible ItemRevenue Maximization subject to BIC and IIR

Extension 1: Sponsored Search Auctions1 seller, multiple buyers, multiple items (positions)

Extension 2: Multi-unit Procurement Auctions1 buyer, multiple sellers, multiple units, discounts

Extension 3: Optimal Combinatorial AuctionsSpectrum auctions


BIC

AE

WBB

IR

SBB

dAGVA

DSIC

EPE

GROVES MYERSON

VDOPT

SSAOPT CBOPT

MECHANISM DESIGN SPACE


Ph.D. Problems: Example 2 Social Network Analysis: A Game Theoretic Approach

Social Network Analysis is an important current problemwith numerous applications and desperately in need of

efficient algorithms

Idea: Use game theory to model social networksChallenge: Social networks could be huge in size

Problem 1: Influence Maximization in Social Networks

(Cooperative Game Theory – Shapley Value)

Problem 2: Discovering Communities in Social Networks(Non-cooperative game theory – Nash equilibrium)

Problem 3: Predicting Topologies of Social Networks(Uses both cooperative and non-cooperative game theories)


Characteristics of a Good Ph.D. Problem

Should be an important, relevant, contemporary problem

Should address a significant research gap

Should be non-trivial, non-incremental, deep,intellectually challenging

Should be a feasible and tractable problem: should take polynomial time


Ingredients of a Good PhD Program: Research Training Program

Strong Background is an essential ingredientof the PhD process

RTP involves picking up this background in arigorous way

6 to 8 courses would be ideal. Mathematical andanalytical courses are especially important

Good textbooks are ideal companions


Ingredients of a Good PhD Program: Reviewing the State-of-the-Art

Involves reading relevantpapers very carefully

This leads to identifying research gaps andidentifying a good research problem

This will help identify important, currently active, currently relevant problems

Internet and the web play an important role in this


Ingredients of a Good PhD Program: Awareness of the Current Art and

Positioning of Work Awareness of the Journals and Conferences

in the area

Awareness of leading research groups, research papers, researchers in the area

Awareness of research gaps and open problems

Clarity of how the proposed work can be positionedwith respect to the current art


Ingredients of a Good PhD Program: Abstraction, Analytical Modeling

Mathematical abstractions lead toprecision and rigour in research

Top quality Ph.D. theses are invariably founded onsolid mathematical abstractions and concepts


Ingredients of a Good PhD Program: Sound Experimentation

Design of experiments is very important

Each graph that is drawn must have a specificpurpose and plan

Insights from the experimental results must bebrought out very clearly

Simulation based studies must be accompanied byconfidence interval estimation, etc.


Ph.D. ThesisChapter 1: Background, Motivating Problems,

Research Gap, Importance and Relevance,Contributions, and Thesis Outline

Chapter 2 typically should contain allpreliminaries

Chapters 3, 4, 5, etc. are the contributory chapters

Results, Conclusions, Summary, Future Work

Bibliography


An Example of a Ph.D. Thesis: Social Network Analysis: A Game Theoretic Approach

Chapter 1: Social Network Analysis, Motivating Examples, High Level Review, Case for Game Theoretic Approach, Contributions, outline

Chapter 2: Social Networks, Social Network Analysis,Relevant Game Theory

Chapter 3: Influence Maximization in Social Networks

Chapter 4: Discovering Communities in Social Networks

Chapter 5: Predicting Topologies of Social Networks

Chapter 6: Summary and Future Work

Chapter 7: Bibliography


Key Success Factors for a PhD Program

Work on important problems

Try to find connections between seemingly unrelated problems

Commitment, deep involvement, good planning

Work hard, continuously, and persevere

Don’t depend on luck; be creative

Breadth and depth are both important


Challenges

Wading through and keeping track ofthe ocean of literature

Identifying a good problem; rising above mediocrity;going beyond a safety zone

Striking a balance: between depth and breadth;between basic and applied

Doing justice to the teaching requirements and family; time management

Planning, Passion, Perseverance, Patience, Perfection, are the key

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Questions and Answers …

Thank You …


Qualities of a Good Researcher

Motivation, Aptitude, Passion

Creativity and Originality

Rigour, Grasp, Perseverance, Eye for detail,Breadth as well as Depth

Strong Background

Curiosity and Spirit of Enquiry

VTU PhD Workshop

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