Fun with Amazon Web Services

Amazon has been doing a really great job at selling excess compute capacity in their datacenters through products such as Amazon Elastic Compute Cloud (EC2), Elastic MapReduce, and their simple and structured distributed storage products. The economics of this kind of model, as represented in the two graphs here are clearly compelling. Instead of buying large numbers of computer to mostly sit idle, new start-up companies, researchers, and individuals can rent the excess capacity from Amazon instead. Last year I worked on some related ideas for internal pricing and provisioning of resources at work. This was my first direct experience with the Amazon consumer offerings however, and I was impressed. It took less than half an hour last night to sign up, start a few basic Linux instances, copy some application code over, compile it, and begin running it on the Linux Xen instances.

Not everything is so easily scaled to run on more computers. Some tasks are more feasibly done with human involvement, and I've also been experimenting with Amazon Mechanical Turk as well. This service is named after the 18th century fake chess-playing machine that actually used a hidden human operator to control the device. I have used this service recently to improve the captions for FreeBSD technical conference videos that I am involved with and the results have been stunning.

The results of cheap on-demand distributed computer clusters and a global english language work force that can be paid by the task almost engender too many business ideas to contemplate.. If only there were more hours in the day..

Support Simon Singh and Scientific Debate

Simon Singh has been sued for libel by the British Chiropractic Association. Simon is an author, journalist, and TV producer who works to popularize math and science. I had the opportunity to hear Simon speak about an earlier book on the Big Bang at Keble College, Oxford. Simon wrote a more recent book on alternative medicine and suggests that there is no evidence for the efficacy of chiropractic treatments for asthma, ear infections, and other infant conditions. British Libel laws are more strict than those in the U.S. and this scientific debate has unbelievably been construed as a form of libel. Read more about the dispute and sign the petition here.

Erdős Number

My current Erdős number is 4. There are several paths of length 3 from my M.Sc. advisor, Joël Ouaknine, to Paul Erdős. The path currently returned by the AMS Collaboration Distance Calculator is:

• Murray Stokely coauthored with Joël Ouaknine
  
• Joël Ouaknine coauthored with A. W. Roscoe
  
• A. W. Roscoe coauthored with Mary Ellen Rudin
  
• Mary Ellen Rudin coauthored with Paul Erdős
  

Dice Wars

I was almost completely unaware of the phenomenon of Flash Games until late last year when a friend of mine started working at a company that makes ads for them. I recently discovered the Dice Wars game which is a typical example of the genre. It is simple yet addictive. The basic premise is similar to the classic board game Risk. Unlike the board game however, the board is smaller, you can not transit armies, army placement is random, and games are much much quicker.

Although the dice layout is completely random, it is addicting because much of the game involved strategy of placement. New armies are awarded after each turned based on the largest connected set of game territories your armies control. As with Risk, you roll one die for each army and the sum of the faces for all N attacking dice is compared to the sum of the faces for all M defending dice with defenders winning the tie. Some quick R code can be used to compute the probabilities of winning a given attack given N attacking armies and M defending armies. The left column represents the number of attacking dice and the first row represents the number of defending dice. Each cell represents the probability of a successful attack given M vs N fair dice.

Dice	1	2	3	4	5	6
1	.4167	.0926	.0116	.0008	2e-05	0
2	.8380	.4437	.1520	.0358	.0061	.0077
3	.9730	.7786	.4536	.1917	.0607	.0149
4	.9973	.9392	.7427	.4595	.2204	.0834
5	.9998	.9879	.9093	.7181	.4637	.2424
6	.999997	.9982	.9753	0.884	.6996	.4667

Back after a 4 year hiatus...

I've imported a number of short posts I made on a previous personal blog from 2004-2005 and relaunched this as blog.stokely.org. My posts in the past tended to be short updates about travel plans or links to pictures. Those type of updates now go to something like Flickr, Facebook, or Twitter, so I'll be using this blog to post less frequent but longer musings about technology, math, computer science, travel, and life in the bay area. I try to keep things partitioned across three separate blogs so that friends and family are not inundanted with posts about which they are uninterested:

• blog.stokely.org - This blog: general posts about my life, math, technology, and more.


• freebsd.stokely.org - Posts about my involvement with the open-source FreeBSD Operating System.


• ava.stokely.org - Posts about Ava and our life with a new baby girl.

Returning to Industry

I've decided to accept a position at Google and postpone the Ph.D. for now. We are moving to Mountain View next week. Our new apartment is 1 mile from downtown and 2 miles from the Googleplex. Pictures are available here.

Summer Events - Garden Party, Ball, etc.

I've posted a few pictures of summer events from the last few weeks of Trinity Term at Wadham. These include the Finalists/Graduates Garden Party with the Warden, and the Burlesque Ball.