Posts by Nick 26

I done plenty of deleting directories I didn't mean to using badly defined variables but two similar cockups stand out in my memory:

The first I've done a few times is accidentally adding an additional / to the "src" of an rsync command when trying to update a subdirectory, for example:

$ ls /bar

aaa bbb ccc ddd eee

$ ls /path/to/foo

file

$ rsync -a --delete /path/to/foo /bar

$ ls /bar

aaa bbb ccc ddd eee foo

$ rsync -a --delete /path/to/foo/ /bar

$ ls /bar

file

There's then a slow dawning realisation of what's happen, I swear profusely and think "oh shit, where can I get that data back from?"

The other was when I was a young misguided tcsh user and I was telling some veteran ksh users how good it was because it had features like "set rmstar" where it would warn you if you do "rm *" and proceeded to demonstrate this in my home directory on my network login on a different machine than I normally use in a shell where it was unset, much hilarity ensued.

Carefully chosen benchmark comparison

Classical simulated annealing is not a particularly good optimization technique which was acknowledged in the paper:

"It is often quipped that Simulated Annealing is only for the 'ignorant or desperate'."

There are much better classical optimization technique which would compare much more favourably but they used it because it was the closest analogue to quantum annealing.

Simulated annealing also doesn't do well with potential energy surface which contain deep, narrow wells where it can get trapped. Quantum annealing can tunnel very efficiently through them and so they chose a problem which suited it. From the paper:

"carefully crafted proof-of-principle problems with rugged energy landscapes that are dominated by large and tall barriers"

Easy fix is to turn off mobile data for hungry apps

I was hitting my data limit before WiFi-assist.

I went with the strategy of turning off mobile data for every app I had installed.

I then turned it back on as and when I first needed it.

I haven't hit my data cap since, not even with WiFi-assist and haven't noticed any loss of functionality.

iOS gives you the information about how much data different apps are using right in the settings,

Not necessarily two sockets

Nathan Hobbes wrote: "Not to state the obvious, but this explicitly talks about having 2 separate sockets, one for handsfree (mic/headphones) and one just for headphones"

Claim 1 ends with "said input-output and output interfaces to be jointly employed for said first and second headsets where said first and second headsets being the same headset" which at a stretch capturess the single connector with a single headset option.

In that case the prior art would be a mobile phone which played music/radio before 2001.

@ John Savard

"one thing that wasn't mentioned was latency - or single-thread performance. Not everything can be parallelized well."

If your problem doesn't parallelize well and single thread performance is your main concern then you would buy a different (and much cheaper) machine.

Yes it was safe

The pilot was right.

RDX is very stable.

They could have used it to boil the water for the in-flight drinks because it burns rather than explodes (although it's not something I'd advocate trying).

Re: F@H

Chris Simpson wrote:

"What about Folding@Home, Granted not one single computer but 5+ Petaflop"

What Folding@Home does is millions of slighty different small problems.

What a supercomputer does is one very large problem.

The difference is tolerance to latency.

The answer to one F@H problem is independent of the other problems and so it can be task farmed. If you're dealing with one big simulation then you need as fast as possible communication between all the CPUs otherwise you'll be waiting an eternity for your answer.

Let's say you want to do some molecular dynamics on a piece of material the size of a grain of salt. Just holding the coordinates and velocities of all the atoms would require about 10 petabytes of memory. The drive for larger simulations, smaller approximations and finer resolutions will continue to feed these machines although Amdahl's law and other software engineering problems are raising their heads.

FM

The reason they want to close down FM is so that they can flog the frequencies to mobile networks