Building Skills in Python: A Programmer’s Introduction to Python by Steven F. Lott (© 2002, 2005, 2007, 2008 Steven F. Lott).

MathIsFun offers nicely illustrated pages on math, algebra, geometry and maybe more.

For example, there is a step-by-step instruction on calculating variance and standard deviation for a set of measured dog heights, with a final picture (below) illustrating one-sigma distance from the mean. Unfortunately, concepts of normal distribution and %% of data points within each sigma range are not discussed, but that might as well be too much for a nice explanation. There are also animations, like this mean machine. Overall, MathIsFun is a nice resource for younglings.

Just a quick note: upgrading Drupal using a patch file is a really efficient and fast method, especially because diff/patch files are available for different Drupal version combinations.

A nice report on the cost of bruteforcing variable-length and variable-complexity passwords using cloud computing services (e.g. Amazon’s EC). There’s a kind of a tutorial in their previous post.

Slow DoS attack with just 1 computer against a number of web servers, including Apache: slowloris. There is a solution for Apache, packaged for RedHat and also available for Debian.

Finally, there’s Go programming language. The most inspiring promise to me personally is the ease of execution parallelization with language’s built-in syntactic constructs. That is something highly desired. Also, I like that it is a compiled language. However, it might be 10%-20% slower than pure C. Let’s see how it grows.

ocrodjvu = OCRopus (tesseract) + DJVU

It is a small command-line tool to easily convert your image-only DJVU files into image+text DJVU files. In Debian testing, there are language packages for (in no specific order) German, English, French, Spanish, Vietnamese, Brasilian Portuguese, Dutch, and Italian. The original tesseract-ocr software includes training data & code, so it should be (at least in theory) easy to add more recognition languages.

Production: see http://www.howtoforge.com/how-to-set-up-apache2-with-mod_fcgid-and-php5-on-debian-etch – it is for Debian Etch (which is old-stable), but many of the steps apply equally well to Debian Lenny (current-stable). Also, this is a very basic guide, as if you are going to host multiple sites from multiple clients, you most definitely will need some hosting control panel.

Development: see http://www.ruzee.com/blog/2009/01/apache-virtual-hosts-a-clean-setup-for-php-developers. This setup works very well, unless you need to create several virtual hosts every day – in which case necessary actions could be partially scripted.

PwdHash uses your “single password” to create a site-unique password (by making a one-way hash of your password and the site’s domain).

Although I’m not using “single password for all sites”, PwdHash does look very convenient.

Today Google celebrates the invention of the barcode.

To help in this celebration, you can make a barcode with your site’s address (there is at least one more at barcodesinc, but at the moment of writing it is painfully slow).

I find these parameters nearly optimal:

• Type: Code 128-B
• Styles: Draw value text
• Size: 234×60 (half-banner size)
• Xres: 1
• Text font: 5
• Value: bogdan.org.ua

If you wish, you can also exactly replicate today’s Google logo – which says “Google”, as you could have guessed.

You can place this barcode on your “souvenirs” – pens, cups, t-shirts. Many phones now have barcode scanners (e.g. Nokia E71), so put this code onto your namecard.

Read on to learn about matrix barcodes.
Read the rest of this entry »

DIYbio is

an organization that aims to help make biology a worthwhile pursuit for citizen scientists, amateur biologists, and DIY biological engineers who value openness and safety.

DIYbio also has a google group, where a wide range of questions – from bio-patents to DIY gel electrophoresis shopping list and model organisms is dicussed. There is also a DIYbio/biohacking FAQ.

Today for me is the day of discoveries. I learned about the International Open Space Initiative (to give robotics enthusiasts a way to send their tele-controlled and/or intelligent robots to the Moon and Mars), about the DIYbio and biohackers, about OpenManufacturing (which doesn’t seem to have produced enough content to link to), Open Source Medicine (ouch!), BioBrick Assembly Kit (with an assembly manual), OpenWetWare, and a whole bunch of other awesome and inspiring community efforts, which do not belong here.

Do you feel the wind of change?

Stumbled upon SciVee.TV – an open video upload service for research-related videos.

I believe it is highly useful. Compare: watching an 8-10 minute video of someone’s research to reading their article on that same subject. For me, those 8-10 minutes make video option a clear winner.

One of the envisioned uses of SciVee is to upload videos describing peer-reviewed published articles. This has two benefits for the reader: quickly getting acquainted with the essence of the article, and having that article as a complete reference for any questions not discussed in the video. For the author, this gives an additional bonus of higher visibility of his research.

Personally, I’ve immediately found 3 videos pertinent to my topic. Of those, one was accompayning an article in PloS Biology, one was an hour-long lecture, and one was a poor quality audio recording of someone’s intended research.

SciVee is young, and that is currently the largest drawback: not much could be found in a narrow research field. But I’m sure it will grow.