Archive for April, 2010
Spacepirates: Ship Layout
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
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
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
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
\includegraphics[width=6in]{figure.pdf}
References
ps2pdf bounding box & page size problem – LinuxQuestions.org