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Meeting 2 [June 1, 2011, 11:26 p.m.]


 

NOTE: This is a wiki page -- anyone can add to this. Feel free to add/correct info here!

For people not at UMD, feel free to organize meetups at other locations! Add it here so people can find you. 

University of Maryland:

We'll be meeting Wednesday, June 1 at 6pm in AVW 3122 (we might go outside again if it's nice). Feel free to email Jessy with any questions jessy at cs dot umd.edu. We'll post discussion points, links and worked solutions to this page. 

University of Texas At Arlington : 

If anyone from UT Arlington is interested, let me know and I will schedule some time for meeting.


UMD Meeting Discussion points/summary

  • Main concepts from the chapter
  • Benford's law
  • Philosophy of normal distribution (WHY is it so prevailent in nature?)
  • identities, summations, etc. 

We spent most of our time going through the chapter. We discussed some of the proofs in detail: 

  • jensen's inequlity
  • conditional expectation
  • the proof on page 45-46 of the branching process example
  • the proof of lemma 10 (in the digital version, the number is different in the hard copy), in particular why the interchange of sums with the change of limits is justified, and why the second sum simply becomes an extra 'j' term. 
  • none of us were clear as to why exactly the authors included the explicit statement that, "the interchange of (possibly) infinite summations is justified, because the terms being summed are all non-negative." why is this qualification needed? what bad things could happen if some of the terms WERE negative?

We spent some time remembering/discussing properties of various equalities, identities, and distributions including:

  • the harmonic, geometric, and arithmetic means
  • binonial identity
  • the factorial form of the binomial coefficient

we discussed but didn';t solve in detail problems 1,5 and 6. but unfortunately we found the chapter rather dense and none of us had much time to do problems this week.

we also discussed that after chapters 3 and 4, it would be nice to take a short break from reading and have a week focused just on solving problems. 

feel free to add/edit other stuff. just trying to get some memory jogs down :). if/as we solve more problems we should post them.