Overall, unless your goal was to build a miniature microwave (a 21st century E-Z Bake Oven?), I don't know why you'd want to use 10GHz instead of 2.4Ghz ones. The tolerances of parts in the magnetron and waveguide would have to be much tighter, I think, and this would almost certainly cause it to be more expensive.
A better NTFS write suppport will be greatly appreciated...
Have you tried asking Microsoft about this ? Perhaps, while they are writing a Linux patch they could also stop Windows from fragmenting files so much.
You tell me which is more likely to happen.. the UAV is never programmed to make that decision to attack, or the military accepts the possibility of some collateral losses.
Hint: Some automated defense systems on ships already make these decisions without human intervention.
I would prefer to say that the system designers (or whoever made up the requirements) made the decision. If the program is instructed to fire on objects moving towards the ship at faster than a certain rate then when it does fire it no more "decided" to do so that you decided to blink when you got a foreign object in your eye.
In fact considerably less so - as you can try to stop blinking to fish it out, while the system will continue firing until the ammo is exhausted or mechanical failure occurs.
I thought the charge was on the parts of the plates nearest each other, so the surface area would only be that of the ends of the nano-tubes. This would be smaller than if they had a flat plate!
Yes. In addition, even if this was made to work (say kinda like a velcro), there is still the issue of *energy*. A battery holds a good deal of it (that's why some explode when shorted) and to charge it in the matter of minutes when it usually takes hours would mean a *much* higher current.
A regular NiMH AA battery has about 1500 mAh (some are better), which is about 7.5 kJ.
Charging it in 2 hours means using a current of 0.75 A. Charging it in 2 minutes means using current of 45 A. At 1.5 V this can cause some very serious heating if the wires are not think enough.
Now if I take the result and short the terminals with a wire and we assume the disharge lasts 10ms it means a current of 540000 A - instant Z-machine !
There are a few later on (much later than the electronegativity slides) that mention band gap theory, but looks like they rely on the speaker to fill in the details.
Someone should tell him that the Hindenburg skin being made of rocket fuel is not such a solid theory.
Also, I found the slides describing metals vs nonmetals to be oversimplified and misleading. Not an unusual thing to miss in a chemestry course though.
You see, one can consider crystal as one giant molecule. The ability to conduct relates to how much electrons are tied to the atoms - does the electric field to move the electrons can be weak, or does it have to be strong enough to tear atoms out ?
Now analogously to what we see in the first slides (with comments on Hydrogen and Bohr's atom) the classical E-M model of the crystal is unstable, electrons would fall down on nuclei. So we have quantum mechanics (and more precisely Hizenberg principle) forcing them to mill about the nuclei.
Just like in the atom, inside the crystal there are possible "orbitals" electrons can fill - though they occupy whole intervals of energy spectrum.
To move an electron within an atom one needs to tear it from existing place and put it in a new one - this requires much energy, except when levels are close by (such as changing between different p orbitals).
In crystal, as long as we move within one energy band very little energy is required and so we have conductance.
This might seem to imply that most materials are metals, but there is one important exception - if the band is completely filled with electrons the exclusion principle does not let them move. This is just like a Noble atom - the crystal does not want to exchange electrons with anything and to force it to do this you need to overcome the gap to the next band (just like using halogen gas to oxidize Argon).
Now in some substances this gap is pretty small - these are called semiconductors.
Both require -staggering- accuracy that a PC, or your USRP board, are incapable of providing. Clock skew considered perfectly acceptable in a PC is considered monumentally inaccurate in a GPS receiver...and the timing resolution isn't anywhere near good enough either. You're talking about comparing timing in LIGHT FEET, and light takes 1/299,792,458th of a second to travel a meter. It's about one NANOSECOND a foot, so you need resolution exceeding 10nS.
You've got to do a lot of signal processing to ignore spurious signals, as GPS signals love to bounce off some things, and get absorbed readily by others. You've got to have an incredibly low noise, highly sensitive receiver, as GPS is readily absorbed by just about anything, and that includes trees.
10ns corresponds to 100Mhz frequency. AFAIK USRP sampling rate is around 16 Mhz (someone knowledgeable please correct me!) however this is provided by crystal oscillator so it is stable to at least 1/10 of the cycle. In fact, it should be way better or the phase noise in the ADC will be very noticeable.
So instead of using PC clock one can simply use the sample number from USRP as a timing source.
I've been staring at a cube for a half-hour now and I can't for the life of me find a hole. Can somebody please explain why my cube has no holes? Does your cube have a hole? Someone please show me the hole!!
Wait, that came out all wrong.
Actually, if you are talking about a regular box (with 2d surface), it does have a 3-dimensional hole in it.
Look up homotopy and mappings of 3-dim sphere into 2-dim one for more details (sorry, there is no way to post a formula on Slashdot..)
While I applaud Mr. Bloombergs speech to me he represents a rather puzzling person. Why is this guy a repulican. Not just him but also people like arnold schwarzenegger, Andrew Sullivan etc. I mean if you are not against gay marriage, if you don't think pre-emptive war is a good idea, if you are pro life then why are you are republican. Before anybody says anything about fiscal responsibility or smaller government I will ask you to go look up the track record of republican presidents regarding those items.
I am especially puzzled about Andrew Sullivan. This guy is gay, the republican party tried to pass a platform saying that homosexuality was a disease!. They are trying their best to deny him the right to marry, to serve his govt, live wherever he chooses etc and yet he is still a republican. Can anything be more important to you then having the same rights as everybody else in the country?
A person who regularly votes Republican, told me that people who are actually more active in the party are often of extreem (and sometimes cooky) type, in particular this happens when Presidential candidates are decided on.
So instead of people like Bloomberg or Guiliamo, we get Bush.
Really, you'd think there'd be a stronger showing from the historically economically powerful countries like Britain, Germany, and France. What's keeping them on the sidelines?
Part of this has to do with the culture of small business in the US. To have one you need a product that someone needs and you need to be better then the incumbent. Eventually this leads to more visible brands.
In contrast, a lot of people in other countries see success as getting a steady pay out of existing entity. So you have large companies like Philips, Sony, etc growing larger and having more products, but under the same brand. It rarely makes sense to have redundant offering from the same company, so the choice is smaller as well.
This probably goes double for the software, as the success of the particular product is hard to plan, so US has an advantage from higher number of independent attempts.
I thought the current dual-socket motherboards (eg this board) could already accept dual-core Athlon (well, Opteron) chips (eg: the 270 series) to make a quad-core machine ?
Yes. The new board appears to be more consumer-level and hopefully less expensive.
What I am really hoping for is the vague "other processors" note - perhaps this is also meant as a responce to Cell and the other socket could be populated with a DSP chip. That would be fun !
However, I can't even begin to grasp the variation in licenses associated with linux programs. Anyone else as clueless as me?
No. Unlike commercial EULAs (see one that comes with Windows for example) Linux licenses are written in a clear language - what it says is what it intends.
Here is an explanation, just in case:
There are four major licenses: GPL, LGPL, BSD and MIT-X.
From users point of view all are equally good as they allow one to use the program and perform personal modifications.
From distributors point of view GPL and LGPL require that source code be made available so some care needs to be taken to address that.
From developer point of view it is a matter of choice:
Do you dedicate your work to libre(free) software only and require that anything that builds on it be also libre ?
Then choose GPL.
Do you want provisions of GPL, but also have a need to interact (or compete) with closed source software ? Then choose LGPL.
Do you need your software to be available for inclusion in closed source software ? Then choose BSD or MIT-X. Note that you can add additional rights to the licensing of your own code so if you wrote something in GPL you can release it later as BSD. One of uses for BSD license is for collaboration between different closed-source vendors that see the benefits of open source, but depend on closed-source lock-in for their revenue.
If I test the polynomial x**3 with x=1, x=2, x=3, and x=10 that doesn't guarantee that it will work for x=-1 (what if somewhere along there it gets treated as an unsigned int?) or for x=2**64. And it CERTAINLY doesn't guarantee correctness for x=2.4.
And it's not even touching the issue of what the code will do if you give it x="abcde".
Well, this is why one tests multiplication first and why we have IEEE floating point numbers - so one is sure what is happenning. And yes, since the code is executed on actual hardware it would make sense to stress test it by putting in many random values and checking that the answer is right.
Still, suppose you went along my suggestion and then found out that there exists x which produces a wrong result. Due to the known properties of the algorithm and the knowledge of which areas got covered by the test you would be able to deduce quite a bit about what the failure was.
Contrast this with usual approach of sticking code to provide various features and then taking care of interactions by "beta" testing - this is sure to produce lots and lots of untested corner cases that are a whole lot less exotic than non-commutativity of floating point numbers.
In other words, what you are saying is "surrender to mediocrity".
If we think about a binary executable program (machine language consisting of ones & zeros) then we must recognize that the program's memory space has many many states. Open up your favorite word editor. Type in a sentence you're thinking about. Highlight part of it and bold it. Highlight a different part and hit escape seven times. Do you think that this scenario was tested?
At some point in Russia software was called "mathematical equipment". I believe there was a similar term in English, but I forgot what it is.
The point being that people first studied what they want to implement, then formed a mathematical model of it and then wrote the software to implement this model.
With this approach it is not necessary to test every possible way the software is used, but rather enough test cases are made to ensure that the mathematical abstraction got implemented properly (perhaps with some overcoverage to guard against buggy test code).
A simplistic example is computation of a certain polynomial. It is easy to check what the degree is by examining the software and then you need to check that the values are correct in as many (or more) test points as you have coefficients in the polynomial. If all of these are correct - voila, you know that the answer is right for any argument.
Hence the purpose of menus, wizards, hierarchies, preferences and all the other complications us geeks know and love.
Not everyone. The problem with menus, wizards and preferences is that instead of one "Big button" they make
a 100 "tiny buttons" - but still one function each.
If "Big button" is not good enough (sometimes it is - think "Start" on a paper copier), then 100 of these will not do either.
The proper computer interface is the command line - which lets one talk to the AI within the computer in its own language and a canvas-like widget that allows to interact with geometric objects.
pc's for everyone is overpriced crap, especaly desktops
They *are* more expensive than a self-built system, but the thing is there are precious few vendors that would sell me an AMD system in the first place, let alone provide component choice (down to the hard disk model)
If you know a better vendor please let me know - I've been chasing the net for a few days and could not find anything decent, let alone in Boston area (I'd prefer to pick up rather than ship..)
pcsforeveryone have some notebooks with Linux preinstalled. Unfortunately, they seem to gravitate towards NVidia. I have not bought any notebooks from them (yet ?) but did buy a few desktops/workstations, so they are quite reasonable.
not linux related - hard disk with smaller rpms tend to be slower, but produce less heat and noise. They are also usually less expensive. On the other side the newer drives with fluid-dynamic bearings are a lot quieter anyway.
For many years I have bought Dell notebooks - mostly due to the screen resolution which I was after, but also because they usually specified which chips were used.
Nowadays, if I was buying one, I would carefully look at the competition, as everyone has good screens and there are really only few actual manufacturers that make notebooks - everyone else just sells a branded solution (Dell included).
So, in no particular order:
Intel has native wireless drivers - see ipw2100, ipw2200 and later projects on SourceForge. Recent kernels also have this code, though I prefer to just download a recent tarball.
Check linux-laptops website in case someone else has purchased your notebook already, it has extensive listings.
Again, for many years I insisted on ATI graphics - since 2d specs were available (at least under NDA) X was very likely to work quite well. Right now, the support for older chips (before Radeon 1xxx) is quite good, but, AFAIK, the documentation (even 2d !) for newer chips was not released yet. Thus either look at older Mobility chips or find out what is the situation with NVidia binary drivers.
I have heard that Intel has open source drivers for some of their shared memory chipsets, so this might be a reasonable choice, especially with higher memory speeds being available.
(My personal preference is to try to avoid binary drivers as these tend to break when upgrading compiler versions of glibc library. Don't know what I'll be doing in a few years when I start looking for a new notebook.)
in my current notebook I opted not to get a BlueTooth module since I suspected it would not work with Linux. Since then I saw many BlueTooth drivers appear in the kernel so check this option.
network cards have a good chance of working - try to find out the pci ids if you can.
I found hard disk, usb, firewire and cdrom to work without problems in most notebooks I saw.
Not linux related: I found that Dell overcharges on memory. I usually buy a notebook with the smallest amount possible and then get a new stick or two from Crucial.
It wasn't called *DART* for nothing you know.. Even the article mentions this:
Last month, NASA said it won't release the investigative board's full 70-page report, citing sensitive information protected by International Traffic in Arms Regulations.
Re:The real reason Bush wants to go back to the mo
on
Back to the Moon
·
· Score: 1
You guys are COMPLETELY forgetting about space oil!
You mean space gas - there is lots and lots of methane here - on Jupiter moons, comets, etc. You could try to convert it to oil by flying a container close to a Sun so it heat up, though a catalyst will also help.
Slashdot Mirror
Yes, but the heating would be more even.
Have you tried asking Microsoft about this ? Perhaps, while they are writing a Linux patch they could also stop Windows from fragmenting files so much.
:)
Hint: Some automated defense systems on ships already make these decisions without human intervention.
I would prefer to say that the system designers (or whoever made up the requirements) made the decision. If the program is instructed to fire on objects moving towards the ship at faster than a certain rate then when it does fire it no more "decided" to do so that you decided to blink when you got a foreign object in your eye.
In fact considerably less so - as you can try to stop blinking to fish it out, while the system will continue firing until the ammo is exhausted or mechanical failure occurs.
Yes. In addition, even if this was made to work (say kinda like a velcro), there is still the issue of *energy*. A battery holds a good deal of it (that's why some explode when shorted) and to charge it in the matter of minutes when it usually takes hours would mean a *much* higher current.
A regular NiMH AA battery has about 1500 mAh (some are better), which is about 7.5 kJ. Charging it in 2 hours means using a current of 0.75 A. Charging it in 2 minutes means using current of 45 A. At 1.5 V this can cause some very serious heating if the wires are not think enough.
Now if I take the result and short the terminals with a wire and we assume the disharge lasts 10ms it means a current of 540000 A - instant Z-machine !
There are a few later on (much later than the electronegativity slides) that mention band gap theory, but looks like they rely on the speaker to fill in the details.
Nice slides :)
Someone should tell him that the Hindenburg skin being made of rocket fuel is not such a solid theory.
Also, I found the slides describing metals vs nonmetals to be oversimplified and misleading. Not an unusual thing to miss in a chemestry course though.
You see, one can consider crystal as one giant molecule. The ability to conduct relates to how much electrons are tied to the atoms - does the electric field to move the electrons can be weak, or does it have to be strong enough to tear atoms out ?
Now analogously to what we see in the first slides (with comments on Hydrogen and Bohr's atom) the classical E-M model of the crystal is unstable, electrons would fall down on nuclei. So we have quantum mechanics (and more precisely Hizenberg principle) forcing them to mill about the nuclei.
Just like in the atom, inside the crystal there are possible "orbitals" electrons can fill - though they occupy whole intervals of energy spectrum.
To move an electron within an atom one needs to tear it from existing place and put it in a new one - this requires much energy, except when levels are close by (such as changing between different p orbitals).
In crystal, as long as we move within one energy band very little energy is required and so we have conductance.
This might seem to imply that most materials are metals, but there is one important exception - if the band is completely filled with electrons the exclusion principle does not let them move. This is just like a Noble atom - the crystal does not want to exchange electrons with anything and to force it to do this you need to overcome the gap to the next band (just like using halogen gas to oxidize Argon).
Now in some substances this gap is pretty small - these are called semiconductors.
Hmm.. can this be used to boot Linux on an Xbox ?
But adding cavities to design of nitrogen chilled supercomputer so you can cool things there does.
You've got to do a lot of signal processing to ignore spurious signals, as GPS signals love to bounce off some things, and get absorbed readily by others. You've got to have an incredibly low noise, highly sensitive receiver, as GPS is readily absorbed by just about anything, and that includes trees.
10ns corresponds to 100Mhz frequency. AFAIK USRP sampling rate is around 16 Mhz (someone knowledgeable please correct me!) however this is provided by crystal oscillator so it is stable to at least 1/10 of the cycle. In fact, it should be way better or the phase noise in the ADC will be very noticeable.
So instead of using PC clock one can simply use the sample number from USRP as a timing source.
Wait, that came out all wrong.
Actually, if you are talking about a regular box (with 2d surface), it does have a 3-dimensional hole in it.
Look up homotopy and mappings of 3-dim sphere into 2-dim one for more details (sorry, there is no way to post a formula on Slashdot..)
I am especially puzzled about Andrew Sullivan. This guy is gay, the republican party tried to pass a platform saying that homosexuality was a disease!. They are trying their best to deny him the right to marry, to serve his govt, live wherever he chooses etc and yet he is still a republican. Can anything be more important to you then having the same rights as everybody else in the country?
A person who regularly votes Republican, told me that people who are actually more active in the party are often of extreem (and sometimes cooky) type, in particular this happens when Presidential candidates are decided on.
So instead of people like Bloomberg or Guiliamo, we get Bush.
Part of this has to do with the culture of small business in the US. To have one you need a product that someone needs and you need to be better then the incumbent. Eventually this leads to more visible brands.
In contrast, a lot of people in other countries see success as getting a steady pay out of existing entity. So you have large companies like Philips, Sony, etc growing larger and having more products, but under the same brand. It rarely makes sense to have redundant offering from the same company, so the choice is smaller as well.
This probably goes double for the software, as the success of the particular product is hard to plan, so US has an advantage from higher number of independent attempts.
Yes. The new board appears to be more consumer-level and hopefully less expensive.
What I am really hoping for is the vague "other processors" note - perhaps this is also meant as a responce to Cell and the other socket could be populated with a DSP chip. That would be fun !
No. Unlike commercial EULAs (see one that comes with Windows for example) Linux licenses are written in a clear language - what it says is what it intends.
Here is an explanation, just in case:
There are four major licenses: GPL, LGPL, BSD and MIT-X.
From users point of view all are equally good as they allow one to use the program and perform personal modifications.
From distributors point of view GPL and LGPL require that source code be made available so some care needs to be taken to address that.
From developer point of view it is a matter of choice:
And it's not even touching the issue of what the code will do if you give it x="abcde".
Well, this is why one tests multiplication first and why we have IEEE floating point numbers - so one is sure what is happenning. And yes, since the code is executed on actual hardware it would make sense to stress test it by putting in many random values and checking that the answer is right.
Still, suppose you went along my suggestion and then found out that there exists x which produces a wrong result. Due to the known properties of the algorithm and the knowledge of which areas got covered by the test you would be able to deduce quite a bit about what the failure was.
Contrast this with usual approach of sticking code to provide various features and then taking care of interactions by "beta" testing - this is sure to produce lots and lots of untested corner cases that are a whole lot less exotic than non-commutativity of floating point numbers.
If we think about a binary executable program (machine language consisting of ones & zeros) then we must recognize that the program's memory space has many many states. Open up your favorite word editor. Type in a sentence you're thinking about. Highlight part of it and bold it. Highlight a different part and hit escape seven times. Do you think that this scenario was tested?
At some point in Russia software was called "mathematical equipment". I believe there was a similar term in English, but I forgot what it is.
The point being that people first studied what they want to implement, then formed a mathematical model of it and then wrote the software to implement this model.
With this approach it is not necessary to test every possible way the software is used, but rather enough test cases are made to ensure that the mathematical abstraction got implemented properly (perhaps with some overcoverage to guard against buggy test code).
A simplistic example is computation of a certain polynomial. It is easy to check what the degree is by examining the software and then you need to check that the values are correct in as many (or more) test points as you have coefficients in the polynomial. If all of these are correct - voila, you know that the answer is right for any argument.
Not everyone. The problem with menus, wizards and preferences is that instead of one "Big button" they make a 100 "tiny buttons" - but still one function each.
If "Big button" is not good enough (sometimes it is - think "Start" on a paper copier), then 100 of these will not do either.
The proper computer interface is the command line - which lets one talk to the AI within the computer in its own language and a canvas-like widget that allows to interact with geometric objects.
They *are* more expensive than a self-built system, but the thing is there are precious few vendors that would sell me an AMD system in the first place, let alone provide component choice (down to the hard disk model)
If you know a better vendor please let me know - I've been chasing the net for a few days and could not find anything decent, let alone in Boston area (I'd prefer to pick up rather than ship..)
Nowadays, if I was buying one, I would carefully look at the competition, as everyone has good screens and there are really only few actual manufacturers that make notebooks - everyone else just sells a branded solution (Dell included).
So, in no particular order:
I have heard that Intel has open source drivers for some of their shared memory chipsets, so this might be a reasonable choice, especially with higher memory speeds being available.
(My personal preference is to try to avoid binary drivers as these tend to break when upgrading compiler versions of glibc library. Don't know what I'll be doing in a few years when I start looking for a new notebook.)
Last month, NASA said it won't release the investigative board's full 70-page report, citing sensitive information protected by International Traffic in Arms Regulations.
You mean space gas - there is lots and lots of methane here - on Jupiter moons, comets, etc. You could try to convert it to oil by flying a container close to a Sun so it heat up, though a catalyst will also help.
More like part of their usual "embrace, extend, extinguish" cycle.
Well, if we compare code to mathematics it does match up - it takes about 2 years to publish a math paper..