September 20th, 2008 by greentheo
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).
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.
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.
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.
Tags: collector, concentration, efficiency, heater, heliostat, panel, sun
Posted in Miscellaneous | No Comments »
September 16th, 2008 by greentheo
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!
Tags: Anti, Linux, Open Source, Virus, Windows
Posted in Code, Miscellaneous | No Comments »
September 3rd, 2008 by greentheo
While I was in Africa this summer I worked out how I could aim several mirrors at my old water heater. I had already stripped off half the casing and foam insulation on the water and heater and painted it black knowing that I wanted to acheive some sort of solar water heating but had never really worked out how to position the mirrors to make it really hot!
So, being a mathematician I set about working out the requisite formulas which would help me to space out the mirrors and determine at which angle I should keep them.
It turns out that instead of tracking the sun it’s actually quite simple to place the water heater perpendicular to the sun, and array the mirrors facing north. Aligning the mirrors in the center with the long edge running perpendicular to the sun means that at midday there will be an additional 8 sq. ft of solar power to heat the water that will eventually be contained in the heater.
In the first picture we can also see that there are 2 additional mirrors placed at 45 degrees in either direction to the middle mirrors. These mirrors are testing my hypothesis that at about 11 am (a little past quarter day) and 3pm there will be some additional sunlight that could be caught.
Once I get a little more funding for this project I’ll add a few more mirrors (4-10) more and also start work on a smaller concentrator for my home office.
Later I’ll connect up some actual water pipes, and circulate the hot water into the house for our new radiant heating system that I’m hoping to install this fall.
If you’d like to code for your own project please contact me.
Posted in Code, Math, R | 5 Comments »
August 13th, 2008 by greentheo
I recently figured out how to do city level Geo targetting with OpenX ad server and spent many hours trying to find documentation on this feature.
I’ve summarized the process below.
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Posted in OpenX Ad Server | No Comments »
April 30th, 2008 by greentheo
I’m currently doing some work on Mutli-Agent Algorithms for a company in the UK and I thought it might make a nice topic for a post.
A multi-agent algorithm is an algorithm that attempts to simulate a complex phenomenon and thereby solve or make useful predictions and strategies for the phenomenon using millions of simulated autonomous agents.
For example, consider the stock market. The price of each individual stock may seem quite random when viewed on a large scale. However, upon further inspection we can see that the current price of a stock is the result of thousands of interactions over time between a set of traders. Each trader brings his knowledge, his expectations and his goals to the trading floor causing small shifts in price.
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Posted in Math | 1 Comment »
April 17th, 2008 by greentheo
I used to work at DoubleClick… now Google… as a Statistical Analyst. In my short career there I learned that internet ads are very rarely clicked on. In fact a rate of 1 in 1000 clicks/deliveries would be considered pretty decent.
Lately I’ve noticed that life seems to be a bit like an Internet Advertisement.
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April 16th, 2008 by greentheo
Back in high school we learned that any right triangle inscribed inside of a circle has vertices on a point on the circumference and two points on the opposite ends of the diameter (if the right angle vertex is on the circumference).
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April 9th, 2008 by greentheo
One of the hard parts about life is choosing one option at the expense of another future opportunity
For instance. When looking for a job it’s rare that you get three competing offers at one time. It’s more likely that you can get one interview/offer this week, and a different possibly better offer next week. If we take the current possibly sub-optimal offer we forgo next weeks potential offer for the security of an immediate pay check. However if we don’t take today’s offer and wait for next week we may both have greater financial security and greater job satisfaction… or we may have nothing at all.
In Artificial Intelligence the same applies, every decision made is a decision that commits the program/robot to a course of action which forgoes future options.
The questions to ask are: How do I design a program/robot to make decisions when faced with choices? How do I allow the program to learn from mistakes and make generalizing principles to help guide it when faced with a decision next time?
Of course we might also ask ourselves these very same questions: How do I make decisions? What are my generalizing and guiding principles?
Posted in Machine Learning | 2 Comments »
April 7th, 2008 by greentheo
Mathematicians and Statisticians are often asked, and usually in a highly dubious tone, “so…. what are you going to do with that advanced stats/math degree?”. Sometimes it’s followed with, “teach?”
So many people must have asked this question that the department of Statistics at Colombia University put on a whole conference devoted to the subject. The conference included panelists from both Academia and Industry.
A Postdoc from the department, commented on the conference.
I thought the following was a good observation:
There is not as much flexibility in industry as with academia (research must be in the companies interests), however, the compensation is usually much better.
All industry panelists agreed that statisticians must be excited by data.
It’s true, to be a good mathematical/statistical researcher you must be excited by data!
Posted in Statistics | No Comments »
April 1st, 2008 by greentheo
Since greentheo.scroggles.com was heading in a more green/political/philosophical direction I thought I would start another blog mostly for sharing code snippets, discussing Artificial Intelligence, Machine Learning and other things Math related.
You might say that this is an Applied Math blog. (Yikes!)
So to kick it off here is an interesting article I found today about a company who provides a handwriting analysis service for potential employers.
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