I think this refers to particular subassemblies in cars. Also, I think this method (JIT subassembly manufacture) was pioneered for the auto industry in Japan, by Toyota in particular.
Read the fucking parent post: a guy asks a fucking question and I give a straight (and correct) fucking answer.
There's more fact in this single fucking comment than in the rest of the useless drivel you fools have vomited out on page combined. (For example, every single comment about Moore's law.)
Don't get me started on integration in the complex plane.
The thing here that always seemed almost too sweet to me here was how you could neglect details of the closed contour and just count the residues. Man that shit rocks.
Actually, it's not all that difficult. Essentially, complex functions f(z) can be considered as mappings from one (complex) plane to another. Differentiation can then be performed just as in the multi-variable case.
The beauty is, if your complex function is analytic (smooth) everywhere (or almost everywhere), then differentiation is just the same as in the case of single varable functions of the reals ({f:R->R}), only the variable is a complex number.
For example,
d/dx(exp(a*z))=a*exp(a*z)
for a complex variable z and a complex constant a.
Just a question, how come the time to and from a synchronous orbit is 1/2 a second, but I can talk to my mother on the other side of the planet with no noticable delay?
Are the satelites an order of magnitude higher than the earth is wide?
It doesn't have 'negative energy' it just has an opposite charge.
It's funny you say that, because antimatter was predicted to exist solely on the force of negative energy solutions of the Dirac equation (the Dirac equaction is the relativistically correct "version" of the Schroedinger equation).
Essentially what you say is correct though, in that resolving the negative energy problem forced a change in the sign of the charge.
There is nothing magical about anti-electrons (say) they're identical to 'normal' electrons
Along with the charge sign change, there is also a change in a quantity known as "lepton number" (for a given system the lepton number is, surprisingly, the number of leptons;-). Basically, the lepton number of a system is invariant, so when you make an electron and a positron (both of which are leptons) the positive and negative lepton numbers cancel [1+(-1)], so there is no change in the lepton number of the system.
So it isn't really accurate to say that they are identical.
I don't have any details either, but my guess is that the "quantum" information (phase, polarisation, etc) is spread out over a number of atoms (analogous to a hologram). The second pulse required to extract the information, I presume, uses it's own phase information to get at the information of the stored pulse.
Or something.
Anyway, I haven't had time to read it yet, but you can get all ther details you want from the nature paper (mirrored).
Mind you, these are *not* NP-Complete problems (at the moment).
I think they're not NP complete full stop. I don't have the references at my fingertips, but due to the Shor factorisation algorithm (for quantum computers). You can define a class (I think called QP#) of all problems with probablistic polynomial time solutions on a quantum computer; factorisation is one of these.
Now, it has been shown using the random oracle that NP complete problems are not in QP#. So factorisation is not NP complete.
And everyone bitches about quantum computers not having practical uses, but here is a straightforward result;-)
Are you serious? You actually think that humans could possible build a machine that could decode thoughts realtime from brain impulses?
At the moment it's a massively nontrivial task to tell if monkeys are looking at black or white. Do you think a computer (no matter how much people idolise the things) could tell the difference between two basic thoughts? For a start you'd have to interface to some massive fraction of the number of nerve cells, then you'd have to get all this data to a huge computer somewhere and have it analysed. And for what? The best way to find out what someone is thinking is to just ask them. There'll never be a computer that can read peoples' minds anywhere near as well as a good trial lawyer who's trained to study faces.
The effects of quantum cryptography is huge... Using a quantum computer would allow you to crack huge keys (everything from PGP, RSA, DES, TwoFISH, BlowFISH, etc.... anything you can think of) because of the essential basis of quantum physics...
Acually, I don't think there are any published attacks for symmetric cyphers (most block and stream cyphers, if memory serves). The only published attack is Shor's famous factorisation algorithm. You're right that RSA is broken wrt quantum cryptography: it relies on the difficulty of factorisation (or synonymously, the difficulty of the discrete log).
AFAIK, all public key systems rely on the discrete log, whereas few (none that I know of) "private key" systems do.
This is not to say that there are no possible attacks on private key (symmetric) systems; there are just none published.
Actually I should be the one apologising. The reason my post was in reply to yours was because yours was one of the few coherent posts on the page.
My beef was really with the massive number of lame Pi jokes elsewhere on the page, and the general content of the comments here in general (despite the fact that my comment added little).
As an example of what I am talking about see this ridiculous comment in reply to the steganography story. The reply is sheer (irrelevant) dogma. Alone I could ignore this kind of thing, but there are just so many morons around here.
Slashdot Mirror
English has no gender-neutral nominative singular pronoun, fool.
The cathode rays.
I think this refers to particular subassemblies in cars. Also, I think this method (JIT subassembly manufacture) was pioneered for the auto industry in Japan, by Toyota in particular.
How the fuck is this a troll?
Read the fucking parent post: a guy asks a fucking question and I give a straight (and correct) fucking answer.
There's more fact in this single fucking comment than in the rest of the useless drivel you fools have vomited out on page combined. (For example, every single comment about Moore's law.)
Fucking idiocy.
The thing here that always seemed almost too sweet to me here was how you could neglect details of the closed contour and just count the residues. Man that shit rocks.
Right, sorry.
The beauty is, if your complex function is analytic (smooth) everywhere (or almost everywhere), then differentiation is just the same as in the case of single varable functions of the reals ({f:R->R}), only the variable is a complex number.
For example,
d/dx(exp(a*z))=a*exp(a*z)
for a complex variable z and a complex constant a.
Or Gallium Arsenide. Pity the fab plants cost so much to build.
That is *really* clever
I don't think "arbitrator" is really a word, or if it is, it shouldn't be. Same situation for "obligated" and "obliged".
WTF?? Moderated down? This is fucking clever.
Just a question, how come the time to and from a synchronous orbit is 1/2 a second, but I can talk to my mother on the other side of the planet with no noticable delay?
Are the satelites an order of magnitude higher than the earth is wide?
It's funny you say that, because antimatter was predicted to exist solely on the force of negative energy solutions of the Dirac equation (the Dirac equaction is the relativistically correct "version" of the Schroedinger equation).
Essentially what you say is correct though, in that resolving the negative energy problem forced a change in the sign of the charge.
There is nothing magical about anti-electrons (say) they're identical to 'normal' electrons
Along with the charge sign change, there is also a change in a quantity known as "lepton number" (for a given system the lepton number is, surprisingly, the number of leptons;-). Basically, the lepton number of a system is invariant, so when you make an electron and a positron (both of which are leptons) the positive and negative lepton numbers cancel [1+(-1)], so there is no change in the lepton number of the system.
So it isn't really accurate to say that they are identical.
Just read through some of your past comments, am I right in guessing you're a physics grad student?
I don't have any details either, but my guess is that the "quantum" information (phase, polarisation, etc) is spread out over a number of atoms (analogous to a hologram). The second pulse required to extract the information, I presume, uses it's own phase information to get at the information of the stored pulse.
Or something.
Anyway, I haven't had time to read it yet, but you can get all ther details you want from the nature paper (mirrored).
This is very clever. I wish I had mod points.
I think they're not NP complete full stop. I don't have the references at my fingertips, but due to the Shor factorisation algorithm (for quantum computers). You can define a class (I think called QP#) of all problems with probablistic polynomial time solutions on a quantum computer; factorisation is one of these.
Now, it has been shown using the random oracle that NP complete problems are not in QP#. So factorisation is not NP complete.
And everyone bitches about quantum computers not having practical uses, but here is a straightforward result;-)
After all, a synonym for popular is common.
So heart disease is one of the more popular causes of death?
Oh can you imagine?!?!?!? That'd be terrible!!! You'd, like, delete your brain, or all your knowlege or.... something!!!!
and recursively as well!!!!!
You'd really be in a dilly of a pickle then!!!!!
Are you serious? You actually think that humans could possible build a machine that could decode thoughts realtime from brain impulses?
At the moment it's a massively nontrivial task to tell if monkeys are looking at black or white. Do you think a computer (no matter how much people idolise the things) could tell the difference between two basic thoughts? For a start you'd have to interface to some massive fraction of the number of nerve cells, then you'd have to get all this data to a huge computer somewhere and have it analysed. And for what? The best way to find out what someone is thinking is to just ask them. There'll never be a computer that can read peoples' minds anywhere near as well as a good trial lawyer who's trained to study faces.
are you at UNSW? if so, which faculty?
I did a stint of neuroscience but now I'm down at physics
An African or European swallow?
Acually, I don't think there are any published attacks for symmetric cyphers (most block and stream cyphers, if memory serves). The only published attack is Shor's famous factorisation algorithm. You're right that RSA is broken wrt quantum cryptography: it relies on the difficulty of factorisation (or synonymously, the difficulty of the discrete log).
AFAIK, all public key systems rely on the discrete log, whereas few (none that I know of) "private key" systems do.
This is not to say that there are no possible attacks on private key (symmetric) systems; there are just none published.
Dave
And with good reason.
Actually I should be the one apologising. The reason my post was in reply to yours was because yours was one of the few coherent posts on the page.
My beef was really with the massive number of lame Pi jokes elsewhere on the page, and the general content of the comments here in general (despite the fact that my comment added little).
As an example of what I am talking about see this ridiculous comment in reply to the steganography story. The reply is sheer (irrelevant) dogma. Alone I could ignore this kind of thing, but there are just so many morons around here.