Question: ask teachers if they really do get that holiday time.
The bad or burnt out ones: they take the holiday time.
The good ones: are learning more stuff during that time, going to meetings, etc.
The really good ones: are spending that time going over the semester results, reading up on new educational stuff, doing up new lesson plans, proactively assembling new exams/tests/assignments, etc.
It's one of those common fallacies that school teachers only work school hours and school days. The reality is slightly scarier.
It depends how they do it. If they've done it by making their additions a binary kernel module, they've not (clearly) broken the GPL.
Lots of vendors ship binary only kernel modules. Can you imagine how screwed up things would get if the courts ruled right now that binary kernel modules are considered as GPL tainted when loaded into a GPL piece of software?
The Wikipedia article points out that the German PBR was a prototype built in the late 60's and operational until the late 80's. A prototype. Built in an era where we were still getting a clue about this stuff.
Please use that article as an example of incorrect management/use of a prototype of an early technology that we need to evolve a little further. Same as any other early technology.
Instead, read this report, linked off of the Wikipedia article:
No, the CCA (clear channel access) check is done at a signal level, not "can I decode this."
The problem with adjacent signal interference is that it doesn't necessarily appear as a solid, high signal level. It can appear like short, pulse like bursty interference in your receiver-on-a-different-channel.
CCA is supposed to be "I can't transmit at the moment because there's _some_ signal present above -X dBm." It feeds into the general air contention and exponential backoff stuff that should be done - ie, the air has to be continuously clear for all that time before the device starts transmitting.
No, RTS just relies on nodes being able to see each other.
The problem with RTS is the standard hidden node problem. If you have two APs that can see each other, then any RTS each sends to a client will be seen by the other AP, which will back off. But, if clients can see all the other clients (and APs) then they can't hear the RTS being sent (or the CTS being replied); and thus they don't update their NAV.
.. really? Yes there is. It's marginal but there is.
The point of having more channels means you don't end up with so much overlap, so the overlap you do have is at weak signal levels. But still, there's overlap.
It doesn't work as well as you'd like, when using omni-directional antennas. If you're using APs with those crappy metallic or printed antennas - heck, even a lot of laptops cheap out on the antenna design - you'll end up just dumping more energy into a crap antenna.
Hi. FreeBSD open source wireless developer here. I also work for a wireless company but this is all my own writing and is not endorsed or linked to my employer.
Don't do that. Let me repeat - don't increase TX power from what the card and regulatory limits say you can transmit.
Besides the regulatory limitations, the card may actually degrade if you increase the TX power. You may end up pulling more power than the card is designed or rated at. You may end up causing the output amplifiers to distort, which means you're not only breaking regulatory by spewing noise into adjacent channels, you're actually making your transmissions _worse_. It gets worse with higher transmission rates (especially 802.11n where the higher TX rates have much higher power density than the lower ones) - the Atheros driver implements per-rate TX power limits for this specific reason.
Chances are the manufacturer just has poor cooling, cheap part selection and all of that finely tuned RF front end is slowly degrading as a result. Buy an AP with better cooling or add better cooling yourself.
In fact, if you run the hardware at a _lower_ power output, you may find it lasts longer.
Dude. Please go and speak to a game developer about the screwed up graphics driver nightmare under windows.
Then realise that the same exists on Linux.
A lot of effort goes into the Windows + (all the different versions of graphics drivers out there) nightmare. Linux would at _least_ be that kind of screwed up to maintain. That's a lot of manpower for no specific revenue targets. No PHB is going to agree to that.
Now if Linux had a sane, stable graphics environment that provided the same experience on all platforms.. everything would be sweet. But PCs don't let you get away with that.
Problem - 60GHz is currently very near-space wifi. It's also what, a couple of gigabit worth of bandwidth. Also, I haven't seen any studies yet looking at 60GHz saturation and lots of multi-path reflection. It's a cool technology but it does read like someone's trying to sell the tech, rather than really being suitable for it.
Yes, because lots of old cars is a great way to keep your car economy going. I like second hand cars (and I spent my first 12 driving years driving them) but it doesn't create a sustainable manufacturing economy.
"Curiosity can communicate with Earth directly at speeds up to 32 kbit/s, but the bulk of the data transfer should be relayed through the Mars Reconnaissance Orbiter and Odyssey orbiter. Data transfer speeds between Curiosity and each orbiter may reach 2 Mbit/s and 256 kbit/s, respectively, but each orbiter is only able to communicate with Curiosity for about eight minutes per day.[32]"
"The data rate direct-to-Earth varies from about 500 bits per second to 32,000 bits per second (roughly half as fast as a standard home modem). The data rate to the Mars Reconnaissance Orbiter is selected automatically and continuously during communications and can be as high as 2 million bits per second. The data rate to the Odyssey orbiter is a selectable 128,000 or 256,000 bits per second (4-8 times faster than a home modem)."
So the rover can communicate with MRO a lot quicker than a modem. The limit now is the uplink back through the DSN.
And that's a single Mars uplink. And there's a lot of data processing on the receive side of the deep space network. It's not just a normal modem.
Maybe a bunch of orbiting deep space network telescope antennas? Well, they're very _big_. Likely bigger than any single dish that we've attached to something in space before.
Besides, it would be good to get experience with this kind of stuff..
Because you don't live in a world where individuals' actions have no effect outside of the individual.
If two people decide to get in the ring and box, and suffer brain damage in the long term, so be it. What effect could it have?
If a hundred thousand pairs of people decide to get in the ring and box, what kind of long term effects will that have on the people around them? Would there be an increase in accidents? A decrease in critical thinking? What kind of effects would it have on their planning and execution skills? What about those families whose fathers/mothers/daughters/sons are suffering from boxing effects and what stresses/effects does it have on them?
Done at a large enough scale, _everything_ has an influence on society as a whole.
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Question: ask teachers if they really do get that holiday time.
The bad or burnt out ones: they take the holiday time.
The good ones: are learning more stuff during that time, going to meetings, etc.
The really good ones: are spending that time going over the semester results, reading up on new educational stuff, doing up new lesson plans, proactively assembling new exams/tests/assignments, etc.
It's one of those common fallacies that school teachers only work school hours and school days. The reality is slightly scarier.
It depends how they do it. If they've done it by making their additions a binary kernel module, they've not (clearly) broken the GPL.
Lots of vendors ship binary only kernel modules. Can you imagine how screwed up things would get if the courts ruled right now that binary kernel modules are considered as GPL tainted when loaded into a GPL piece of software?
The Wikipedia article points out that the German PBR was a prototype built in the late 60's and operational until the late 80's. A prototype. Built in an era where we were still getting a clue about this stuff.
Please use that article as an example of incorrect management/use of a prototype of an early technology that we need to evolve a little further. Same as any other early technology.
Instead, read this report, linked off of the Wikipedia article:
http://juwel.fz-juelich.de:8080/dspace/handle/2128/3136
That's a much more interesting read than the article.
ok, you win the internet tonight.
Because it's an open GL -reference- implementation.
No, the CCA (clear channel access) check is done at a signal level, not "can I decode this."
The problem with adjacent signal interference is that it doesn't necessarily appear as a solid, high signal level. It can appear like short, pulse like bursty interference in your receiver-on-a-different-channel.
CCA is supposed to be "I can't transmit at the moment because there's _some_ signal present above -X dBm." It feeds into the general air contention and exponential backoff stuff that should be done - ie, the air has to be continuously clear for all that time before the device starts transmitting.
Yeah, this stuff is complicated.
No, RTS just relies on nodes being able to see each other.
The problem with RTS is the standard hidden node problem. If you have two APs that can see each other, then any RTS each sends to a client will be seen by the other AP, which will back off. But, if clients can see all the other clients (and APs) then they can't hear the RTS being sent (or the CTS being replied); and thus they don't update their NAV.
Adrian
.. really? Yes there is. It's marginal but there is.
The point of having more channels means you don't end up with so much overlap, so the overlap you do have is at weak signal levels. But still, there's overlap.
It doesn't work as well as you'd like, when using omni-directional antennas. If you're using APs with those crappy metallic or printed antennas - heck, even a lot of laptops cheap out on the antenna design - you'll end up just dumping more energy into a crap antenna.
Hi. FreeBSD open source wireless developer here. I also work for a wireless company but this is all my own writing and is not endorsed or linked to my employer.
Don't do that. Let me repeat - don't increase TX power from what the card and regulatory limits say you can transmit.
Besides the regulatory limitations, the card may actually degrade if you increase the TX power. You may end up pulling more power than the card is designed or rated at. You may end up causing the output amplifiers to distort, which means you're not only breaking regulatory by spewing noise into adjacent channels, you're actually making your transmissions _worse_. It gets worse with higher transmission rates (especially 802.11n where the higher TX rates have much higher power density than the lower ones) - the Atheros driver implements per-rate TX power limits for this specific reason.
Chances are the manufacturer just has poor cooling, cheap part selection and all of that finely tuned RF front end is slowly degrading as a result. Buy an AP with better cooling or add better cooling yourself.
In fact, if you run the hardware at a _lower_ power output, you may find it lasts longer.
Dude. Please go and speak to a game developer about the screwed up graphics driver nightmare under windows.
Then realise that the same exists on Linux.
A lot of effort goes into the Windows + (all the different versions of graphics drivers out there) nightmare. Linux would at _least_ be that kind of screwed up to maintain. That's a lot of manpower for no specific revenue targets. No PHB is going to agree to that.
Now if Linux had a sane, stable graphics environment that provided the same experience on all platforms.. everything would be sweet. But PCs don't let you get away with that.
.. for one generation.
Problem - 60GHz is currently very near-space wifi. It's also what, a couple of gigabit worth of bandwidth. Also, I haven't seen any studies yet looking at 60GHz saturation and lots of multi-path reflection. It's a cool technology but it does read like someone's trying to sell the tech, rather than really being suitable for it.
Yes, because lots of old cars is a great way to keep your car economy going. I like second hand cars (and I spent my first 12 driving years driving them) but it doesn't create a sustainable manufacturing economy.
Because there's significant signal processing going on with the received signals. And they're different based on the different ages of the spacecraft.
I suggest doing a little digging into what JPL and NASA do on the receive side.
... also, that was for spirit and opportunity.
Curiousity is different:
http://en.wikipedia.org/wiki/Curiosity_rover
"Curiosity can communicate with Earth directly at speeds up to 32 kbit/s, but the bulk of the data transfer should be relayed through the Mars Reconnaissance Orbiter and Odyssey orbiter. Data transfer speeds between Curiosity and each orbiter may reach 2 Mbit/s and 256 kbit/s, respectively, but each orbiter is only able to communicate with Curiosity for about eight minutes per day.[32]"
and [32] is:
http://mars.jpl.nasa.gov/msl/mission/communicationwithearth/data/
"The data rate direct-to-Earth varies from about 500 bits per second to 32,000 bits per second (roughly half as fast as a standard home modem). The data rate to the Mars Reconnaissance Orbiter is selected automatically and continuously during communications and can be as high as 2 million bits per second. The data rate to the Odyssey orbiter is a selectable 128,000 or 256,000 bits per second (4-8 times faster than a home modem)."
So the rover can communicate with MRO a lot quicker than a modem. The limit now is the uplink back through the DSN.
And that's a single Mars uplink. And there's a lot of data processing on the receive side of the deep space network. It's not just a normal modem.
Maybe a bunch of orbiting deep space network telescope antennas? Well, they're very _big_. Likely bigger than any single dish that we've attached to something in space before.
Besides, it would be good to get experience with this kind of stuff..
Really? Do you know what the uplink rate from the rover actually is? Hint. it's not 9600bps anymore.
So now you know that in 4 years time, the minimum fund raising you need to do in your area is $100,000.
Good luck!
That would still be really nice to have online!
.. can we please have those scrapbooks scanned and placed online? pretty please?
.. i'd assume that whatever they were firing would have some kind of guidance control.
It's 2012. Why would you create a dumb ballistic projectile over that kind of distance?
Running in your own direction with open source is only as good as your team of trained monkeys is at keeping things reintegrated with upstream.
It's not "free".
.. wow. [citation needed] and context required please.
Because you don't live in a world where individuals' actions have no effect outside of the individual.
If two people decide to get in the ring and box, and suffer brain damage in the long term, so be it. What effect could it have?
If a hundred thousand pairs of people decide to get in the ring and box, what kind of long term effects will that have on the people around them? Would there be an increase in accidents? A decrease in critical thinking? What kind of effects would it have on their planning and execution skills? What about those families whose fathers/mothers/daughters/sons are suffering from boxing effects and what stresses/effects does it have on them?
Done at a large enough scale, _everything_ has an influence on society as a whole.