Please create an account to participate in the Slashdot moderation system


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×

Comment Log Filesystem - as hardware? (Score 1) 93

This reminds me of the original 'Log Filesystem' research in the 80s, back when drive geometry was known to the OS, and the OS could take steps to optimize for it.

The Log Filesystem concept was to write all data sequentially to disk, and update metadata during idle times.

The basic research influenced a number of filesystems, such as NetApp's WAFL, Sun's ZFS, Linux's JFFS2, etc.

Interesting to see the concept implemented 'in hardware'.

Comment Re:Space station (Score 1) 71

I think there's plenty of oxygen. The trick is to find a way to extract the O2 from the water ice (hopefully there is a percentage of O2 that is simply dissolved in the ice instead of having to use electrolysis) to make it advantageous to burn it with the methane for power.

The equation should end up as the following for a viable mission using methane as a fuel:

Heat cost of producing O2 < Heat generated by burning O2 with atmospheric methane.

Comment Re:STOP!!! You're going the wrong way!!! (Score 2) 233

Actually, this will end up as a carbon sink:

1) Plants are grown for their sugars to feed into this process (carbon sequestered from atmosphere into the roots left in the soil after harvesting, and into animals that the resulting cellulose will be fed to after sugar extraction).
2) Sugar (carbon) from step (1) is fed to the modified E. Coli to make gasoline. "Dead" E. Coli sludge could be used in animal feed, or processed into fertilizer for (1).
3) Gasoline from step (2) is then used for cars/trucks.

The problem is not "gasoline as a fuel", but the "extract carbon from natural sequestration to GET gasoline" that is the issue.

As an energy storage system, gasoline is REALLY hard to beat.

For its energy density, it is one of the safest energy storage systems we have.

Comment Step E: "A miracle occurs...." (Score 1) 233

For more details on 'step e', where the fatty aldehyde is converted to the gasoline alkanes, look up the "cer1 enzyme":

This enzyme is used by plants to create waxy coating on their leaves.

I find this to be a great example of what can happen when people are looking cross-disciple for solutions!

Comment Re:zero (Score 1) 130

Of course, this is also why the IBM system only has '+' and '*' as operators.

Which severely limits the operations you can do on the encrypted system (so long as you aren't given E(-1) as an input).

If given E(-1) as input, you can recover all the integers again, and you can do any arithmetic set of operations.

I think testing for equality is strictly verboten under their system.

Comment Re:zero (Score 1) 130

E(0) is E(a) - E(a)
E(1) is obtained by E(a)/E(a).
E(-1) is E(0) - E(1)

E(2) = E(1) + E(1) ...
E(n) = E(n-1) + E(1)

E(-n) = E(-(n-1)) + E(-1)

And there you go. All the integers - from one encrypted input.

And you can even recover your cyphertext *if* the homomorphic set has a 'is equal to' or a 'is not equal to' operator.

for (i = 0, ei = E(a)-E(a); ei is_equal E(a); i=i+1, ei = ei plus E(a) div E(a));

At the end of the loop, i == a.

Comment Re:Some hardware needs them (Score 1) 558

Once upon a time (circa 2000), I wrote a Linux driver for the damned thing, fully supported by SanDisk.

It's Made of Evil. You need special software to be able to ready/write it (since it only has the read/write area that contacts the head on side 0, track 0), only transfers at 150K bits/sec (MFM encoded), and uses obsolete memory technologies.

If anyone has one of these crusty things, I might have a version of mtdtools that will work with it laying around somewhere.

If you want a copy, email jason dot mcmullan the-at-sign google's mail dot com

Slashdot Top Deals

"In matters of principle, stand like a rock; in matters of taste, swim with the current." -- Thomas Jefferson