Flexible and Robust Real Time Software Systems

1
Flexible and Robust Real Time Software Systems

• Lui Sha

2
Course Objective

• The objectives of this short course are to help
  you
• to improve your research skills.
• how to identify critical issues,
• how to create a promising research agenda,
• to learn about some of the key ideas for
  building flexible and reliable real-time software
  systems
• The relationship between simplicity, complexity
  and reliability
• A case study
• Some of exciting open problems

3
Outline

• Lecture 1
• Position your research
• How to formulate research
• Lecture 2
• How to present your results
• A class project

4
Lecture 1 Position Your Research

• Questions that we want to answer
• what are the effective thinking and learning
  styles for research
• why every problem is not equal
• what are the key factors you should consider when
  you pick a research area

5
High Levels of Thinking

• The key to become insightful is to exercise the
  higher level (4, 5, 6) of thinking skills as
  characterized by B. S. Bloom - analysis,
  synthesis and evaluation.
• Level 6 Evaluation judge, select, decide,
  critique, verify, debate, assess
• Level 5 Synthesis create, predict, construct,
  design, imagine, improve, produce and propose
• Level 4 Analysis Classify, categorize, derive,
  model
• --------------------------------------------------
  -------------------
• Level 3 Application Calculate, solve,
  determine, apply
• Level 2 Comprehension Explain, paraphrase
• Level 1 Knowledge List, recite
• In this mini-course, I want to help you sharpen
  thinking skills at levels 4, 5 and 6.

6
Active Learning

• After 2 weeks, we tend to remember (Edgar Dale).
• Passive learning
• 10 of what we read
• 20 of what we hear
• 30 of what we see (pictures)
• 50 of what we hear and see
• Active learning
• 70 of what we say
• 90 of what we say and do
• That is why I will try to make you think, say
  things and do things in the class!

7
Picking The Right Problem

• A key attribute of a great general his ability to
  maneuver until he finds the right time, right
  place and right conditions to fight. A key
  attribute of a successful researcher is his
  ability to pick the right research problem that
  is worthy his time.
• Quiz What is the difference between
• a theorem and
• a homework problem?
• They are both derived from the same set of
  axioms.
• Both are correct
• Some homework problems are harder to prove that
  some of the theorems
• If you decide to spend time on a problem,
  shouldnt you work on a problem that is likely to
  become a theorem?

8
Position Yourself
Your Interest
Your Strength
Societal Needs
Research focus
9
Know Thy Strength

• Look inside and find your strength, I excel at

Abstract reasoning
See the big pictures
System dev. experiments
Create polished work
10
Be Truthful to Your Passion

• Thinker The greatest joy is to understand My
  heroes are Newton and Einstein.
• Builder My heroes are Edison and Bell ... They
  created an entire industries that greatly
  improved the quality of peoples life.

11
Pay Attention to Societal Trends

• The societal reward is largely based on supply
  and demand, not how hard your work.
• If you want to work hard to solve a problem, you
  may as well to work on a problem whose solution
  is cherished by the society at large. For
  example
• As our economy and society become
  increasingly dependent on information technology,
  we must be able to design information systems
  that are more secure, reliable and dependable.
  More RD in this area is desperately needed.
  Information Technology for 21st Century A Bold
  Investment in Americas Future
• See http//www.ccic.gov/it2/initiative.pdf
  for other grand challenges.

12
Be Consistent with Your Strength, Your Passion
and Societal Needs
Your Interest
Your Strength
Societal Needs
Research focus
13
Mini Class work

• Now organize yourselves into teams. And lets
  take some time to know each other.
• each student think carefully and then prepares
  one slide that tells us in 3 min that the
  research area
• you really like to pursue and
• how it relates your
• strength,
• passion
• and societal needs.
• And what you like to do in a group
• This is important because you may spend years or
  even your life time on it. It also helps me to
  assist you to achieve your goal.

14
Lecture 2

• Questions that we want to answer
• why reading papers and literatures alone is not
  sufficient
• how to give lectures/write papers that are
• interesting
• informative
• and insightful
• how to think independently, differently and
  boldly
• your micro-research project

15
Which Way to Go, Please?

• Now you have positioned yourself and selected an
  area. The easiest thing to start research is to
  read a set of papers and do incremental
  improvements.
• Extend a result to make it more general
• improve the efficiency of an algorithm and a
  protocol
• Solve a problem differently and show
  improvements.
• The real question is along which direction you
  would extend and improve? How do you know that
  you are creating a theorem or mere a homework
  problem, so to speak?

16
Von Neumanns Advice

• as a mathematical discipline travels far from
  its empirical source, or still more, if it is a
  second and third generation only indirectly
  inspired by the ideas coming from reality, it
  is beset with very grave dangers. It becomes
  more and more pure aesthetics, more and more
  purely l'art pour l'art'. ... there is grave
  danger that the subject will develop along the
  line of least resistance, that the stream, so far
  from its source, will separate into a multitude
  of insignificant branches, and that the
  discipline will become a disorganized mass of
  details and complexities."
• John Von Neumann, "The Mathematician" an essay
  in "The works of Mind", Editor E. B. Heywood,
  University of Chicago Press, 1957.
• Dont do it just because it is obvious or easy
  for you.
• Do it if it leads towards the solution of a
  significant real world problem.

17
Want to be Real? Know the Real World

• Dont invent solutions and then look for
  problems. It may work but the odds are poor.
• Listen to von Neumanns reflection of his life
  long work. Talk to developers, look at incident
  reports (what you did at the beginning of this
  class) and then develop the model problems
• what are the common threads/patterns in the
  problems that bogged down development?
• Can I develop a simple model problem that
  embodies the essence of the technical
  difficulties. (Think of dining philosopher for
  concurrency control.)
• Look at the engineering practice. What has been
  overlooked. (Think of Priority Inversion.)
• Look at the literatures. What the simplifying
  assumptions used by the authors that makes their
  live easy but the solution less than practical?

18
Presentation Skills My I3 Model

• I have thought about this for many years. To me,
  a great presentation should be
• Interesting (Tell me more..)
• Informative (Add to my knowledge base...)
• Insightful (Impart a deeper understanding ...)

19
Being Interesting

• Interesting arousing ones curiosity...
• The apparent evidences should lead to the
  innocent and the murderer should be the one that
  is least suspected.
• Build a model of your audiences mind-sets, and
  maximize the unexpected events. Topics should
  be interesting to the audience
• For intellectuals with an inquisitive mind, this
  often means
• something seemingly unimportant actually holds
  the key
• something widely believed to be true turns out to
  be not true
• new and significant ideas, results, connections
  between different areas
• counter-intuitive, unbelievable results
• something insightful (see Slides on Insightful)

20
Being Informative

• Inform give new knowledge...
• New is relatively to your audience.
• what they already know?
• what they should know after my presentation?
• what are the steps in-between?
• Why from specific to general and from concrete
  example to abstract is the preferred style
  presentation?
• Consistent with how most people learn
• Give an easy to grasp anchor first
• Easy to involve the audience and make them think
  actively

21
Being Informative - 3

• Can you tell me what is the fundamental
  difference between
• the notes that you take
• the presentations that you make
• Presentation is audience centered Do they
  already know this? Can they follow the argument?
  Do I need a picture? An example?...
• Tips for getting the information across
• be energetic in your presentation, maintain eye
  contacts
• pay attention to your audiences reactions and
  adjust your presentation
• get them active and get them involved whenever
  you can

22
Being Insightful

• Insight getting right to the heart of a complex
  problem, shedding lights on,,,
• explain a seemingly complex and confusing problem
  in a way that is easy to understand
• unearth hidden/unstated assumptions... And
  quickly put an argument to rest
• showing things in new angles, new lights and new
  forms and gain new understandings e.g., Fourier
  Transforms,
• demonstrate subtle but important
  connections/inter-dependencies between seemingly
  unrelated subjects e.g., identify the link
  between Aspirin and heart attack

23
Class Excises

• Thinking independently and thinking differently
  from prevailing assumptions/opinions
• 10 km object falls faster than 1 km object
• earth is square
• earth is the center of universe
• time and space are independent
• we should always optimize the use of computer
  resource. No, GUI
• putting more functions into hardware will run
  programs faster. No, RICS
• large software projects can only be developed
  with centralized control. No, Linux
• interpretive language is dead. No, JAVA
• now, think of more examples on your own
• technologies change, application context change,
  peoples needs change, our knowledge grow
  always re-examine prevailing assumptions

24
A Micro Research Project

• You are hired you a big and tough New York
  bank to design and implement their web site with
  the following requirements
• cost is not the main concern, reliability and
  performance are
• if there is a financial transaction errors due to
  your software, no fee will be paid to you.
• You web site is allowed to be down no more than 1
  hour per year, after that every hour down time,
  you must refund 10 of the fee
• if must keep up with the competition. If the web
  site is ranked as the one of top cool 10 bank
  sites, 20 bonus. If ranked as the top, 50
  bonus
• each team shall give a 10 min presentation on the
  architecture (last lecture).
• major components build vs buy
• The logical relationship between the components