BumScientist

Aquarium Rack

admin — Mon, 02 Aug 2010 09:55:03 +0000

Six 20 gallon tanks in an aquarium rack

SATA > IDE

admin — Mon, 28 Jun 2010 10:30:33 +0000

Turns out sata is 4x faster than ide.

hdparam -t /dev/sda

/dev/sda: Timing buffered disk reads: 80 MB in 3.07 seconds = 26.06 MB/sec

hdparam -t /dev/sdb

/dev/sdb: Timing buffered disk reads: 314 MB in 3.00 seconds = 104.53 MB/sec

Reading websites with PHP

admin — Tue, 08 Jun 2010 02:21:17 +0000

Use cURL.

References

Scraping Links with PHP

Fuppes Slackware 13.2 x86_64 with ffmpeg transcoding

admin — Fri, 28 May 2010 07:42:58 +0000

install ffmpeg

install lame, mad, faad libraries

download fuppes SVN 660

it will give an error about not finding libavformat, so you need to add /usr/local/lib/pkgconfig

$ PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:/usr/lib64/pkgconfig:/usr/local/lib/pkgconfig

$./configure –enable-mad –enable-faad –enable-lame –enable-transcoder-ffmpeg

Spacepirates: Ship Layout

admin — Mon, 12 Apr 2010 10:57:29 +0000

Generator, provides W = J/s = N*d/s

Engines, output has a max horsepower output. 1/2 mv^2 = W*dt + 1/2 m v^2

1 electrical motor hp = 746 W

Railgun, charges at J/s with a maximum capacity.

Radar, quadruple power to double range

1 MW generator, 1000 hp engine, 1 MJ railgun

Railguns, how fast can you go

admin — Mon, 12 Apr 2010 10:43:19 +0000

E = 1/2 m v^2

A railgun has a limited length, to shoot faster, the railgun needs to be longer.

If a 1 kg projectile is shot at 1,000 m/s, it will change the speed of a 1000 kg object by 1 m/s due to conservation of momentum.

Hard Drive Prices

admin — Sat, 10 Apr 2010 09:45:20 +0000

The 3 cheapest hard drive prices for each capacity from newegg. 1.5 TB is still the sweet spot. The slope is much steeper too making 1.5 TB extra sweet. The $/TB went down about $15 from two months ago from ~$80 to ~$65.

Putting Octave Plots in LaTeX

admin — Sat, 03 Apr 2010 10:56:14 +0000

I like vector based formats for my plots if the data is vector based. I input png and pdf to latex. I can output png, eps and pdf from Octave. The problem is that the pdf outptut has extra whitespace. To get around the whitespace, I can copy and paste into powerpoint and save as pdf with a specific page size or I can do the following.

Plot the figure with size on paper set

> fh = figure(‘papersize’,[6 4],’paperposition’,[0 0 6 4]);

Output as a colored encapsulated postscript

> print(‘-depsc2′,’figure.eps’)

Turn EPS to a PDF with proper size. You can edit the pdf later if need be.

$ ps2pdf -dEPSCrop figure.eps

Add figure to paper with proper size

\usepackage{graphicx}

\includegraphics[width=6in]{figure.pdf}

References

ps2pdf bounding box & page size problem – LinuxQuestions.org

LAPACK

admin — Tue, 30 Mar 2010 05:35:55 +0000

$ cp make.inc.example make.inc
$ make blaslib testing
$ make

http://icl.cs.utk.edu/lapack-forum/archives/lapack/msg00046.html

add current directory to library search path

$ gcc -L . -lm -llpack file.c -o executable_file

DSL Video Streaming

admin — Fri, 19 Feb 2010 10:42:55 +0000

The cheapest DSL from AT&T is limited to 768 kbps for downloading. They call it broadband, but with all the video content on the web now, I think people need more bandwidth. If I max out the DSL video streaming, then I can do 128 kbps audio and 640 kbps for video.