Archive for the ‘Miscellaneous’ Category

When computers control all essential societal functionsw

Monday, November 3rd, 2008

It is apparent to a researcher in Machine learning and Artificial intelligence that soon enough machines will be controlling many of the essential resources of our society.  The webs that will be woven by the interdependent parts of our cities and countries  will be held together by increasingly powerful and complex networks of computers.

Since computers can store far more information in their immediate memory and can play out 1,000’s of scenarios per second they are the clear choice for such jobs as: air traffic control, airplane scheduler, train engineer, traffic and road designer, stop light designer, telephone switch operator, and any number of jobs that require such comlex decision making.

I don’t think machines will ever “take over” like they do in the matrix, but the question will soon arise, what happens if we unplug one machine?  What about 20?  Furthermore, what if the machines make apparently sub-optimal decisions… how will we be able to tell if they really were sub-optimal?

I think the most likely worst-case-scenario will begin to be not that the machines take over the world and force us into slavery, but rather that our dependence on them becomes so great that we are afraid to do anything without their consent… even if it means doing something that is right, but crosses logical boundaries.

Problem with ‘Table Full’ for MyISAM DB?

Monday, November 3rd, 2008

If you need to expand your MyISAM table size for your MySQL DB becuase you simply have too much data then this is a nice quick tutorial on accomplishing your goal.

http://jeremy.zawodny.com/blog/archives/000796.html

Basically do the following

mysql> alter table your_table max_rows = 200000000000 avg_row_length = 50;

And that will increase it to its maximum size.

				

Adaptive UI

Thursday, October 9th, 2008

Designing a website, or a User Interface for a program is hard work.  One has to study people and their often hard to predict and difficult to quantity decision making processes.

For instance, google.com shows a clear knowledge that user’s get distracted by anything other than the task at hand if presented with multiple options.  Thus their site has one main focus… a search bar.  They, are are after all, a search company.

google.jpg yahoo-screenshot-2.jpg

But what if User Interface designers, and website designers started to pay attention to the actual math behind user interactions?  Like living organisms, what if the website or user interface adapted to the user?  For instance, if the website knew that people browsing on cloudy days liked a more cheerful design why wouldn’t it brighten up the background?

Or perhaps in Yahoo’s case why not reorder the sidebar links in order of most clicked on?  What about Yahoo’s search bar?  Might that feature become larger and more prominent?

Why aren’t websites and Program designers doing this already?  They may be, but the sheer volume and dynamism of large user bases makes it a very difficult and ever changing job.

I suggest that website and User Interface designers move to a design framework which includes the ability for the site or program to collect user statistics, and then reorganize itself according to some preset rules.  Flex, Flash, php, python and a host of other programming languages could all support these features really easily.  And if you can’t think of a better optimization algorithm, simply allow the user interactions with the site to be a sort of genetic algorithm.

A good analogy for Operations Research

Thursday, September 25th, 2008

The other day I was trying to explain the concept of constrained optimization to an artist.  As I was fumbling around a bit, my friend (who was also a Math nerd) said:

Constrained optimization is like fishing… you have a limited amount of bait, you don’t know what the fish want, how many fish are out there, or what type/proportion they are but the goal is to catch as many as possible in a few hours.

While it’s not a perfect analogy… it’s pretty good.  What’s your favorite analogy for constrained optimization?

Fun with Heliostats Part II

Saturday, September 20th, 2008

This week expanded my first heliostat by adding another 8 sq. ft of mirrors (bringing the total to 24 sq. ft) and have also added a second heliostat.  The second sun collector uses 12 1 sq. ft mirrors (mirror tile from Home Depot or Lowes, $10).

Circular heliostat

I tried to take temperature readings of the second colletor, but ended up frying my thermometer.  Regardless the temperature on the brick gets well over 150 degrees and is unbearably hot (can’t but my hand on it for more than about 1 second).

Overall, the heliostat project is a success and I have determined that the second more circular collector will make a good space heater for the office.  The plan is to put the bricks inside the office window and the mirrors outside.  As the day progresses the brick will heat up and heat up my office.  By the time the sun goes down I’ll be done with work and wont need any more heat.

Circular heliostat closeup

As for the water heater collector, there will be too many drags on heating efficiency and transfer too and from the house.  I’ve decided that it will likely be better to build a flat panel with small pipes to collect the heat and to move the panel much closer to the house.

Water Heater heliostat

Water Heater closeup

Overall, this project has been fun and has really shown me that for a really low cost (<$40 for the second circular collector) one can build a solar powered heater.

In the future I’d like to test what the effect of concentrating the sun on a real PV panel would be.  I’d like to set up two panels  relatively close to each other and test how much more efficient one can make the panel by concentration.  I exepect that a factor of 1.5-2X power will be acheived by focusing 2X the solar area. Perhaps with a third row of mirrors to the circular collector it might be possible to push the efficieny up to 2.5-3X. If this turns out to be the case it will enable the average person to go Solar, bringing down the cost of solar by about half.

Ode to Linux (and Open Source)

Tuesday, September 16th, 2008

The trusty ol’ T43 got sick this weekend with the “Windows Anti-Virus 2008″ virus.  Try as I might, I could not get it off of Windows XP.  I tried everything and every software to no avail.  Luckily I didn’t decide to the buy the “anti-virus” software they were pitching to solve the “virsuses” they had detected on my computer (this particular virus is actually mal-ware which tries to convince you that you have viruses and to buy their software to fix it).

I read tales of woe of those who “bought” the software only to have their accounts drained.

But as I was giving up and cursing windows for making such an insecure Operating System (really? Windows, you couldn’t have prevented such an attack?), I remebered that ntaylor0909 had just given me a copy of Ubuntu Server 8.04….

So I wiped ‘er clean and am now up on Ubuntu Linux.

I have to say so far I’m quite impressed.  It’s free… it works… all the programs for it are free… and they work too… and I hear that it’s even quite secure.

Thank you Linux!

R code for visualizing a reflective surface in 2d

Wednesday, December 19th, 2007

Given that you have some reflective shape expressed in mathematical form the following code written in R will help you to visualize the effect of bouncing light (or potentially audio or any other object) off the surface of the object. It only calculates one bounce however and does not account for multiple reflections…perhaps sometime in the future. This script produces plots like the following:

A circular reflector.

A histogram of the y-intercepts of the reflected rays for a circular dish.

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Unix Completes me too

Wednesday, November 21st, 2007

Though this woman doesn’t quite match up with my preconceived notion of what a “Unix user” should look like I quite agree with her sentiment :-)

Not your typical unix user.

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Website Grader

Friday, November 2nd, 2007

I was reading Guy Kawasaki’s blog “How to change the world” and came across a link to the following site which helps to optimize your webpage for search engines.

After running Scroggles and greentheo through the service I’ve found that there is still work to do! Must continue building and optimizing Scroggles!

Credit Card Mathematics

Monday, July 30th, 2007

Malia and I ate a restaurant this weeked that didn’t accept credit or debit as payment. While I was a bit dismayed at first, the 10-20% lower cost of the meal was more than enough to appease us! It turns out that credit cards are actually quite expensive (up to 5% of the transaction cost) for a business. It seems that the credit card companies have figured out how to make money coming and going.

As such I thought that I would reproduce a piece I wrote a few months ago about the evils of credit cards.
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