Wednesday, August 20, 2003

various topics


 : Support Forum: "" The port to movable type is painful. Off we go...

installation page.

Tuesday, August 19, 2003

Blog it blogit blogs domain names for sale
6.042 Course Overview, Fall 2002 more later.
Secure Shell This is why public key authentication was disabled for me in ssh (my home directory was world-writeable). I likely opened up my home directory for a student to write some data for me, and forgot about it. I'll remember that for next time. I must have missed that small detail in my semi-casual perusal of the ssh man pages. The debug process on this was

  1. become root.
  2. restart the sshd in debug mode.
  3. peruse the output to find the line Authentication refused: bad ownership or modes for directory /net/home/jones
  4. realize I must have opened up my home directory.
  5. change permissions on homedirectory.
  6. restart the sshd in normal mode.

    I'd be interested in hearing other strategies for debugging broken public key authenticaion in ssh using openSSH. In particular, where's the stupid log file???

Monday, August 18, 2003

Bloom: Educational objectives six categories of learning. useful for organizing courses and curricula. I may use these in the coming semester to organize 611 and 586. I am still looking for the text of the source.
Better verification through symmetry Symmetry is preserved when process IDs are only tested for equality as members of an unordered set.

The number of processes in a given state matters, not the order in which processes appear in a given state. So that state 0,1 is identical to state 1,0. (if that state of process A is first and the state of process B is second in the pair A,B). The new problem is determining if two states are members of the same symmetry class. This is done by canonicalization. A canonicalization function returns the same result (namely, the canonical state) for all members of the same class.

So what does it mean for our heuristic? Our cost function should return the same cost for states in the same class. It means we need to find out if we are computing the cost before or after canonicalization.
hist (MATLAB)--histogram and thus begins another foray into the world of "figure out how to get matlab to draw the graph I want." This time, I'll save the pages for future use. Blogging is far more useful than I would have guessed.

Scatter 3 function this might do it, once our data gets put in the right format.

csvread (MATLAB Functions) the parameter format for reading in data from a file. - Apple Ships Power Mac G5 We want one of these to do model checking in 64 bits. Then we could address a hash table of more than 4 GB.

Apple-Power Mac G5 it starts at $1999. But how much is it with 16 GB of memory?quote (may not work) Looks like its about $8000 for one with 8 GB of memory and you can't get more than 8 GB.
A simple fault tolerant distributed hash table This is the paper that mentions terms like "dilation". What is "degree-dilation tradeoff"? What does "spam resistent" mean? Also, look up papers on Chord and Viceroy. This particular paper assumes a lot of background I don't have. Which, hopefully, means papers in the bib will explain the teterms at my level.