What's nice about the patch antenna over the "cantenna" is its broad beamwidth.
Just for the record, `broad beamwidth' is just another way of saying `low gain'.
One attains `high gain' by having a narrow beamwidth. That's all `gain' means when referring to an antenna -- the narrower the beam, the higher the gain.
If you're worried about ping times, no, you can't do much about it. But if all you're after is being able to transfer a massive file in a very short period of time, you can. Ditching TCP entirely and spewing the data via UDP packets, not even waiting for acknowledgements will almost entirely remove the effects of any latency. Only if the remote host needs to re-request any data does latency really become an issue.
One brute force method to avoid that would be to immediately send all the data again. This would be silly here, but if you were sending a file to Mars (the planet) and the many minute latency was a major problem but you had plenty of throughput (but high packet loss), sending everything twice (or more times) might actually be a good idea.
This is already done for some RF transfer protocols -- send everything twice rather than worry about complicated re-request protocols.
More fancy methods involve sending parity/ecc bits that can be used to rebuild a certain amount of missing data.
That would need to mount/dev/hda1/m, of course. There's probably more typos.
No, I don't really expect anybody to actually do this -- there's already much better stuff out there. But several years ago, before all those smart people solved the problem elegantly for you, this was one way that people would solve problems like this -- with a nasty `one off'.
Install a system, configure it the way you want it. Don't install too much stuff, because it needs to fit on a CD.
Once done, boot into single user mode.
tar everything up to *another* disk (mounted here under/mnt) --
cd/ tar --one-file-system --sparse -zcvvvf/mnt/disk.tar.gz/
If that file doesn't fit on a CD with at least 10 MB to spare, remove some stuff and try again. export GZIP=9 might help a bit too.
Get a bootable linux floppy disk image. It doesn't really matter which one, but it does need to have a real filesystem on it (not just a kernel.) Your typical rescue disk will probably work well.
Make a script to install. It'll be something like this --
#!/bin/sh -e # zero the partition table dd if=/dev/zero of=/dev/hda bs=1024 count=10 sync sleep 3 sync # create a 1024mb / partition printf "n\np\n1\n+1024m\nw\n" | fdisk/dev/hda # create the filesystem mke2fs -j/dev/hda1 # mount it mkdir/m/n mount/dev/scd0/cd mount/dev/hda/m # dump your tar.gz file to the new fs cd/m tar --totals --preserve --sparse -zxvf/cd/disk.tar.gz cd/ # (re)install the bootloader echo "/sbin/grub-install/dev/hda" | chroot/m/bin/sh # clean up umount/m umount/cd echo "Ok. Time to reboot!"
and then this script will replace/sbin/init on your boot floppy. Of course, if your floppy starts something other than/sbin/init, you'll need to replace that.
Then you'll burn a cd that contains that floppy image as the el Torito boot image, and has that file.tar.gz in the root of the file system.
This is really rough, and will only work properly with rather specific hardware, but it may get you started. Making a proper distribution is a lot more work than this -- I only spent a few minutes typing this out.
I have not tested any of this. In particular, the command to do the fdisking probably has issues -- for example, most boot floppies don't have printf by default (you'll need to add it, or a script to just print all the fdisk commands), and I probably got the order of some stuff in the printf statement wrong (it's a string of commands for fdisk.) And of course it'll happily trash whatever is on your disk with no warning. (Installing lilo rather than grub can be done with a similar procedure if needed.)
But if you're looking for a really quick and dirty way to install lots of identical machines, this may get you started. This is NOT a procedure for anybody who doesn't really understand what all this stuff does and the possible problems -- I just provided it as a first stab at a possible solution under some limited conditions. Note that the general idea can apply to other OSs as well -- I even remember once making a setup that installed OS/2 (off a network share) just like this -- long before Ghost was a gleam in Norton's (or whomever's) eye.
In any event, I'd suggest seeing what Knoppix has to offer -- if, like another poster suggested, they have a script to just install to a disk, that would probably be far better than this hack.
One handed pilots have been a problem with R/C planes for a long time. People lose a hand, but don't want to lose their hobby...
The standard R/C controller has two sticks, giving you four axis of control (throttle, rudder, elevator, aileron)... absolutely requiring two hands, unless you limit yourself to one stick and therefore only two channels. (Which is fine for some gliders, but is very limiting.)
But people have made controllers where there's only one stick -- to access the other two channels, you rotate the stick and turn a small seperate knob on top of it. It's not as easy to use as the two stick version, but if you've only got one hand, it gets you back in the air.
(You use a tray to hold the transmitter, so you don't have to use your hands to carry it at all.)
I'd love to give a link to one of these, but can't seem to find one right now...
Aha -- found one! here's a picture
and here's the page with more info. Looks like this one only has three axis on that one stick, but that's enough for the important controls of a powered airplane, and perfect for most gliders.
`Destroyed' isn't the right word. Damaged is a better term... of course, each time it happens it makes the weakest cell a little weaker, eventually making the pack as a whole almost unusable (due to that weak cell.)
I've not seen the iPod battery pack, but I suspect it's a 2 cell Li-poly. In that case, the unit should shut off long before either cell could ever be reverse charged. But it's definately a concern when you have more than 3 or so cells, and you have something that doesn't automatically shut off when the voltage drops to a certain amount.
Li-poly batteries are very like Li-ion cells, but they're less likely to explode if overcharged. Beyond that, and the (possible) shape differences, I don't think there's much of a difference.
The link you gave explained it pretty well...
i know that the Li-Ion battery in my TiBook has seen a lot less memory effect...
The Li-whatever cells do not experience memory. (Even NiCd's rarely do under normal use, but voltage depression is often mistaken for it.) They do eventually wear out, however -- perhaps that's what's happening.
NiCds usually have less capacity than NiMH cells, but they last longer (more charge/discharge cycles.)
NiCd -- Needed to be fully charged and drained every single time.
No, not every time. Occasionally is good enough -- the more it's overcharged, the more often you'll need to fully discharge it.
NiMH cells do not show voltage depression (often called memory) so there's no need to worry about fully discharging them.
Li-Ion -- Hard on the battery if it's left full charged constantly.
No it's not. If the charger overcharges them, they could explode, so most chargers know when to stop. The real reason that people say not to leave them fully charged for long periods of time is that they can explode if accidently shorted out.
Li-ion cells are not at all forgiving -- if abused, they either die (fully discharged) or explode/burn (overcharged, short circuted.) It's the needed circuitry (to prevent these things from happening) that's forgiving.
Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.
No battery likes being overcharged. NiCds handle it best, but it slowly eats away at them (assuming a slow charge.) Smart chargers will stop the overcharging, but most chargers for NiCd devices are not smart. So take them off the charger once the battery starts getting warm!
If they are overcharged, or never discharged fully, they'll start to show voltage depression (often mistakenly called memory.) A full discharge will usually resolve this, at least until the battery wears out.
NiMH cells are very like NiCds, but they have more capacity and handle abuse less well. They also don't suffer from voltage depression (often called memory) so there's no need to fully discharge them ever.
Never completely discharge either sort -- go down to 1.0 volts per cell and then stop. Going further can cause the weakest cell to be `reverse charged' making it even weaker. For normal users, this means just use the item until it needs to be charged, but don't just turn it on and leave it going overnight.
Li-Ion cells can *explode* if overcharged, so any decent charger will stop charging them before that happens. So they should be fine to leave on the charger forever.
They'll also die if fully discharged. Fortunately, most things that use them will turn off before this happens, for exactly that reason.
To be complete, lead-acid batteries (like used in your car) should not be overcharged, as it evaporates electrolyte. Good chargers will prevent this, and your car has a good charger in it. Do not leave them discharged for any length of time -- this will ruin them. Fortunately, they self-discharge very slowly, so they can be left alone for a year or so after a full charge and won't die (as long as there is no load.)
iPods and most laptops and cell phones have Li-Ion cells, though some older cell phones and laptops have NiMH cells (and even older ones may have NiCds.)
It may be do both. But I think he's on the right path -- the
link I posted is a bit more specific than the one he did, and this definately looks like it would solve the original question., assuming it works as promised.
I would like to know how it is possible to get a Linux Workstation to authenticate against the user database in our Windows 2000 Server.
When you say `user database', are you referring to the Windows domain, or something like LDAP? I suspect it's the former...
The Windows database doesn't contain all the information that a *nix system needs -- it doesn't know about shells or home directories, for example. (Well, it does know home directories, but they're different.) Even if there was a PAM module that would talk to it, I'm not sure where it would get this information from.
In your case, most people will set up a seperate server for the *nix network, using NIS to share password information. Using PAM you can even set up the *nix box to change the password on the Windows network when it's changed locally.
Alas, it's easier to set up a Linux box as a domain server for a bunch of Windows boxes than it is to make the Windows box act as a NIS server for a Linux network...
Waitaminute. That's it -- you just need a NIS server for the Windows box. Looks like our old friends Microsoft
sells something that may do what you need. (Disclaimer: I've never used it, and probably never will.)
I suspect it (the software) will cost more than a dedicated Linux box NIS server (the hardware), but it may be easier to maintain and sell to management. Personally, I'd prefer the Linux NIS server, but then again, I'm not a Microsoft guy.
What seems more effective would be to post news about this to a popular `geek' web site, allowing disgruntled users to air their grievances and users who don't know about this to read up on what's going on. Hopefully this would shame the company into doing `what's right'.
(Of course, if the company is in a shaky situation financially, the bad press could cause sales to drop to the point that they go under, then nobody gets their deal. Oh well -- they should have thought of that before!)
I don't suppose anybody can think of an appopriate `geek' web site? fark perhaps?:)
MandrakeSoft only turned around after telling everyone that they were about to go out of business.
Seems to work for the local furniture store. GOING OUT OF BUSINESS SALE! EVERYTHING MUST GO!. It's worked so well, they've been `going out of business' for several years now:)
In fact, I think they've even opened a new location up north, and after a month or so it started GOING OUT OF BUSINESS! too!
Various types of "peril" are allowed. The most common cases involve abandoned ships or ships in danger of sinking. However, as argued by claimants in the first Amistad case, the death or disability of the crew, or the seizing of the ship by pirates, can also support a claim for salvage.
I don't see the airplane as fitting any of these categories. It's not abandoned, it's not in danger of being lost. It's not in any danger at all -- it's just not going anywhere without fuel. And Jon isn't dead or disabled.
Jon's lucky that he was able to land the plane somewhere where people could help him. But as far as I know, the plane isn't completely out of fuel and is completely airworthy, except that it can't go very far without additional fuel.
When a vessel goes to anothers assistance in response to an SOS...
Did anybody go to somebody's assistance? As I understand it, Jon landed and probably knocked on the door and asked for help. He may have radioed ahead, but the article did say he landed at the base.
And then your example of how he's wrong is itself wrong, since salvage does apply on the open seas.
Actually, the link you gave says that salvage isn't an option either. If the plane were a ship, the best anology would be that it was adrift, undamaged, not in danger but with minimal or no fuel, and the captain/crew was aboard trying to arrange to get some more fuel. If you were to then take the ship, that would be called piracy, not salvage.
Ah, slashdot.
Indeed.
In any event, as long as Jon isn't thrown out in the cold (no idea what the weather would be like now. It's summer, so it may not be *too* cold), his best bet is probably to keep trying to negotiate for fuel, and if needed, pay somebody to bring him some. Whatever happens, he'd do best to fly the plane out himself.
And then once it's all over, be sure to pay the researchers who brought him in for room and board, even if they don't ask for it. Some extra goodies (you don't get many luxuries when you're in Antacrtica) for the people who helped him out, even if they didn't provide fuel, would also be appropriate. After all, they did, quite possibly, save his life. (No idea about his survival gear, weather, or possibility of a rescue.)
Someday I'll realize that my fingers don't always do what the brain tells them to. Sometimes they type different things entirely, or what they think the brain SHOULD have told them to type. It's wierd...
He didn't have clearance to pull this stunt, despite the fact that it would have been more than easy to ask.
Clearance from who? Who would he ask?
Last I checked, Australia was owned by nobody, by international agreement.
Frankly, I think that his plane should be confiscated
I believe the word for that sort of action would be `piracy'. At least that's what it would be called if it happened in the open seas, in international waters. You don't get to just `take' people's property, and this hardly qualifies as a salvage operation.
I'm sure if these people did loan him some fuel, it would be well payed for. Even if Jon isn't rich, he can afford to pay a few thousand dollars for $200 worth of fuel (that's about how much it would be here, anyways) to save his ~ $100k plane.
Re:Oh Well, there not the first, there not the las
on
Kazaa-lite Shut Down
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Don't do things illegal in your country!
Yeah! Do them in another country!
God bless Canada and the blank media tax; I don't mind paying a little bit on every CD-R for a music piracy license!
The US has a similar law, with similar results. Of course, the tax only applies to digital audio media, including Audio CD-Rs.
Of course, the RIAA isn't going after downloaders (I wonder if they'd win) -- they're going after uploaders. And having paid a tax on your CD-R media won't help there.
The original TTYs were 50 baud. TDD (Telecomunication Device for the Deaf) uses that standard even today. It's pretty easy to type too fast for them to keep up (but modern hardware has a buffer to help keep from losing characters.)
with 1200 baud
Actually, it's not 1200 baud. It's 600 baud, but 1200 bps (bits per second.) Baud and bps do not mean the same thing -- it's bps that you're thinking of.
Isn't there a way to transmit your information so that it can still be recovered if a portion of it is loss?
Absolutely. There's numerous ways of doing this, from complicated things like Reed-Solomon coding to things as simple as just sending each bit of information twice (or more times.)
In the case of a GPS signal, it falls more into the category of the same information being sent over and over. If you failed to determine your position last second, maybe you can do it this second, or next second. As long as you're not moving too fast, as long as you can get some of the signal you're probably fine.
However, if the signal from the jammers is millions of times stronger than the signal from the satellites (which is entirely possible and probably even likely) it's probable that your receiver will *never* get any valid data from the satellites.
agreed to use transmission frequencies that could be easily disturbed or completely jammed
If they're going to use frequencies that can be easily jammed now, I'd really like to know what frequencies they were using before that can't be -- because these frequencies must be magical.
Any signal from a satellite is going to be very weak -- the satallite is a long way away, our atmosphere attenuates the signals somewhat (which does depend on the frequency), and they cannot transmit with very much power to begin with (because they have limited solar power, and cooling is difficult to do in space.)
Any signal from a satellite can be jammed from the ground just by pumping a few thousand (or more) watts into that frequency in the general vicinity. This noise would overwhelm the weak signal from the satellite and drown it out.
It's also quite possible that any yahoo with a big dish and a few thousand watts to spare could jam an entire satellite by aiming the dish at the satellite and transmitting a few thousand watts on the the frequencies the satellite uses (especially the uplink frequencies.) This has happened recently and made worldwide news.
(Of course, I imagine that the only reason they never caught (?) the person (organization? government?) responsible is that they were in Cuba. This sort of jamming isn't trivial to track down, but I'm sure that it wouldn't take long.)
I'd expect GPS-type satellites to be more resistant to this sort of jamming (because I imagine that they don't really use uplink frequencies at all) but one could certainly jam the control frequencies (which may or may not be needed often) and one could probably interfere with the transmitter by flooding it with noise on it's own channel (I guess... my experience with RF electronics is limited.)
I doubt that the government would flood the satellite with noise, however -- I suspect they'd just use equipment to jam the local area.
Battlebots has had requirements for fail-safes on their radio equipment from the beginning.
No, not from the beginning -- it used to be just a suggestion. But now it is a requirement. The Battlebot rules have gotten much better since they first started out.
Still, a full sized car is much much more dangerous than any battlebot allowed by the BattleBot rules, and requires much more care. Merely relying on your PCM radio to protect you from disaster *is not enough*.
you can buy pieces of kit that senses if the radio signal has been lost or the batteries are low. When they detect this they just shut the piece of kit down (ie close throttle or whatver you set it to do).
Yes, and if you have PCM equipment this is built in. However, it's not enough. If the battery gets pulled loose, your servos will all freeze right where they were, and your failsafes will never activate. Or if a big bump cracks your receiver PC board, same thing. Or if your car rolls over and crushes your receiver...
This is a very non-standard configuration. Suppose what would happen if your throttle servo arm broke, or the servo broke loose so it was hanging free. Not hard to imagine, as it was almost certainly mickey-moused into place in the first place. This is a better situation than the loss of battery, as you've still got steering and brakes, but it could still be very bad.
Remember that you can buy RC cars and trucks that do 80mph+ out the box which won't do anyone's ankles/shins any favours- this has already been thought of!
Of course it has. And people have been throwing R/C equipment into full scale cars for decades now too. But now it's being suggested to those who really have no experience with this sort of thing... and yet are crazy enough to try it anyways. This could easily turn into a Darwin award, or worse...
In any event, your average 1/8th scale car doing 80 mph will probably be stopped by a simple barrier of old tires or a curb (it will be pretty to watch though!) The car isn't likely to go far, and even if it did, it's probably only got a few minutes of fuel.
On the other hand, your full scale car will go through that, through a fence, many miles cross country, and perhaps even through a full building -- and keep on going. Depending on the car, it may go well over 100 mph. And there won't be a thing you can do to stop it.
A full scale remote control car requires that much much more care be taken than with your average R/C car, even a high performance one.
I still think the kill switch I suggested is essential. Have it set to kill the power to the distributor, or if you must the fuel pump (though that's not as good, as it would take a while for the engine to die.) Having it be a totally seperate system would allow you to kill things even if the first system was broken -- a car is big and heavy, and it's very likely to be abused, and so and I'd expect lots of failures of the primary control system, from pushing the servos too hard, from physical damage (you'll probably be doing all kinds of crazy things with the car) and from not being mounted properly.
Slashdot Mirror
One attains `high gain' by having a narrow beamwidth. That's all `gain' means when referring to an antenna -- the narrower the beam, the higher the gain.
If you're worried about ping times, no, you can't do much about it. But if all you're after is being able to transfer a massive file in a very short period of time, you can. Ditching TCP entirely and spewing the data via UDP packets, not even waiting for acknowledgements will almost entirely remove the effects of any latency. Only if the remote host needs to re-request any data does latency really become an issue.
One brute force method to avoid that would be to immediately send all the data again. This would be silly here, but if you were sending a file to Mars (the planet) and the many minute latency was a major problem but you had plenty of throughput (but high packet loss), sending everything twice (or more times) might actually be a good idea.
This is already done for some RF transfer protocols -- send everything twice rather than worry about complicated re-request protocols. More fancy methods involve sending parity/ecc bits that can be used to rebuild a certain amount of missing data.
No, I don't really expect anybody to actually do this -- there's already much better stuff out there. But several years ago, before all those smart people solved the problem elegantly for you, this was one way that people would solve problems like this -- with a nasty `one off'.
Once done, boot into single user mode.
tar everything up to *another* disk (mounted here under /mnt) --
If that file doesn't fit on a CD with at least 10 MB to spare, remove some stuff and try again. export GZIP=9 might help a bit too.
Get a bootable linux floppy disk image. It doesn't really matter which one, but it does need to have a real filesystem on it (not just a kernel.) Your typical rescue disk will probably work well.
Make a script to install. It'll be something like this --
and then this script will replaceThen you'll burn a cd that contains that floppy image as the el Torito boot image, and has that file.tar.gz in the root of the file system.
This is really rough, and will only work properly with rather specific hardware, but it may get you started. Making a proper distribution is a lot more work than this -- I only spent a few minutes typing this out.
I have not tested any of this. In particular, the command to do the fdisking probably has issues -- for example, most boot floppies don't have printf by default (you'll need to add it, or a script to just print all the fdisk commands), and I probably got the order of some stuff in the printf statement wrong (it's a string of commands for fdisk.) And of course it'll happily trash whatever is on your disk with no warning. (Installing lilo rather than grub can be done with a similar procedure if needed.)
But if you're looking for a really quick and dirty way to install lots of identical machines, this may get you started. This is NOT a procedure for anybody who doesn't really understand what all this stuff does and the possible problems -- I just provided it as a first stab at a possible solution under some limited conditions. Note that the general idea can apply to other OSs as well -- I even remember once making a setup that installed OS/2 (off a network share) just like this -- long before Ghost was a gleam in Norton's (or whomever's) eye.
In any event, I'd suggest seeing what Knoppix has to offer -- if, like another poster suggested, they have a script to just install to a disk, that would probably be far better than this hack.
Roughly 100 years ago, the world record for powered airplane speed was probably under 60 mph ... I imagine it's somewhat faster now.
(Of course, `Internet Speed Record' ... who really cares? I'll care when I can have this transfer rate to my house for $60/month :)
The standard R/C controller has two sticks, giving you four axis of control (throttle, rudder, elevator, aileron) ... absolutely requiring two hands, unless you limit yourself to one stick and therefore only two channels. (Which is fine for some gliders, but is very limiting.)
But people have made controllers where there's only one stick -- to access the other two channels, you rotate the stick and turn a small seperate knob on top of it. It's not as easy to use as the two stick version, but if you've only got one hand, it gets you back in the air.
(You use a tray to hold the transmitter, so you don't have to use your hands to carry it at all.)
I'd love to give a link to one of these, but can't seem to find one right now ...
Aha -- found one! here's a picture and here's the page with more info. Looks like this one only has three axis on that one stick, but that's enough for the important controls of a powered airplane, and perfect for most gliders.
I've not seen the iPod battery pack, but I suspect it's a 2 cell Li-poly. In that case, the unit should shut off long before either cell could ever be reverse charged. But it's definately a concern when you have more than 3 or so cells, and you have something that doesn't automatically shut off when the voltage drops to a certain amount.
The link you gave explained it pretty well ...
The Li-whatever cells do not experience memory. (Even NiCd's rarely do under normal use, but voltage depression is often mistaken for it.) They do eventually wear out, however -- perhaps that's what's happening.NiMH cells do not show voltage depression (often called memory) so there's no need to worry about fully discharging them.
No it's not. If the charger overcharges them, they could explode, so most chargers know when to stop. The real reason that people say not to leave them fully charged for long periods of time is that they can explode if accidently shorted out.Li-ion cells are not at all forgiving -- if abused, they either die (fully discharged) or explode/burn (overcharged, short circuted.) It's the needed circuitry (to prevent these things from happening) that's forgiving.
Li-poly cells are more forgiving, but with most of the benefits of Li-ion cells. I don't know how popular they are outside of R/C applications, however.
No battery likes being overcharged. NiCds handle it best, but it slowly eats away at them (assuming a slow charge.) Smart chargers will stop the overcharging, but most chargers for NiCd devices are not smart. So take them off the charger once the battery starts getting warm!
If they are overcharged, or never discharged fully, they'll start to show voltage depression (often mistakenly called memory.) A full discharge will usually resolve this, at least until the battery wears out.
NiMH cells are very like NiCds, but they have more capacity and handle abuse less well. They also don't suffer from voltage depression (often called memory) so there's no need to fully discharge them ever.
Never completely discharge either sort -- go down to 1.0 volts per cell and then stop. Going further can cause the weakest cell to be `reverse charged' making it even weaker. For normal users, this means just use the item until it needs to be charged, but don't just turn it on and leave it going overnight.
Li-Ion cells can *explode* if overcharged, so any decent charger will stop charging them before that happens. So they should be fine to leave on the charger forever.
They'll also die if fully discharged. Fortunately, most things that use them will turn off before this happens, for exactly that reason.
To be complete, lead-acid batteries (like used in your car) should not be overcharged, as it evaporates electrolyte. Good chargers will prevent this, and your car has a good charger in it. Do not leave them discharged for any length of time -- this will ruin them. Fortunately, they self-discharge very slowly, so they can be left alone for a year or so after a full charge and won't die (as long as there is no load.)
iPods and most laptops and cell phones have Li-Ion cells, though some older cell phones and laptops have NiMH cells (and even older ones may have NiCds.)
The Windows database doesn't contain all the information that a *nix system needs -- it doesn't know about shells or home directories, for example. (Well, it does know home directories, but they're different.) Even if there was a PAM module that would talk to it, I'm not sure where it would get this information from.
In your case, most people will set up a seperate server for the *nix network, using NIS to share password information. Using PAM you can even set up the *nix box to change the password on the Windows network when it's changed locally.
Alas, it's easier to set up a Linux box as a domain server for a bunch of Windows boxes than it is to make the Windows box act as a NIS server for a Linux network ...
Waitaminute. That's it -- you just need a NIS server for the Windows box. Looks like our old friends Microsoft sells something that may do what you need. (Disclaimer: I've never used it, and probably never will.)
I suspect it (the software) will cost more than a dedicated Linux box NIS server (the hardware), but it may be easier to maintain and sell to management. Personally, I'd prefer the Linux NIS server, but then again, I'm not a Microsoft guy.
What seems more effective would be to post news about this to a popular `geek' web site, allowing disgruntled users to air their grievances and users who don't know about this to read up on what's going on. Hopefully this would shame the company into doing `what's right'.
(Of course, if the company is in a shaky situation financially, the bad press could cause sales to drop to the point that they go under, then nobody gets their deal. Oh well -- they should have thought of that before!)
I don't suppose anybody can think of an appopriate `geek' web site? fark perhaps? :)
In fact, I think they've even opened a new location up north, and after a month or so it started GOING OUT OF BUSINESS! too!
Jon's lucky that he was able to land the plane somewhere where people could help him. But as far as I know, the plane isn't completely out of fuel and is completely airworthy, except that it can't go very far without additional fuel.
Did anybody go to somebody's assistance? As I understand it, Jon landed and probably knocked on the door and asked for help. He may have radioed ahead, but the article did say he landed at the base. Actually, the link you gave says that salvage isn't an option either. If the plane were a ship, the best anology would be that it was adrift, undamaged, not in danger but with minimal or no fuel, and the captain/crew was aboard trying to arrange to get some more fuel. If you were to then take the ship, that would be called piracy, not salvage. Indeed.In any event, as long as Jon isn't thrown out in the cold (no idea what the weather would be like now. It's summer, so it may not be *too* cold), his best bet is probably to keep trying to negotiate for fuel, and if needed, pay somebody to bring him some. Whatever happens, he'd do best to fly the plane out himself.
And then once it's all over, be sure to pay the researchers who brought him in for room and board, even if they don't ask for it. Some extra goodies (you don't get many luxuries when you're in Antacrtica) for the people who helped him out, even if they didn't provide fuel, would also be appropriate. After all, they did, quite possibly, save his life. (No idea about his survival gear, weather, or possibility of a rescue.)
Someday I'll realize that my fingers don't always do what the brain tells them to. Sometimes they type different things entirely, or what they think the brain SHOULD have told them to type. It's wierd ...
I meant Antartica, of course :)
Last I checked, Australia was owned by nobody, by international agreement.
I believe the word for that sort of action would be `piracy'. At least that's what it would be called if it happened in the open seas, in international waters. You don't get to just `take' people's property, and this hardly qualifies as a salvage operation.I'm sure if these people did loan him some fuel, it would be well payed for. Even if Jon isn't rich, he can afford to pay a few thousand dollars for $200 worth of fuel (that's about how much it would be here, anyways) to save his ~ $100k plane.
Of course, the RIAA isn't going after downloaders (I wonder if they'd win) -- they're going after uploaders. And having paid a tax on your CD-R media won't help there.
In the case of a GPS signal, it falls more into the category of the same information being sent over and over. If you failed to determine your position last second, maybe you can do it this second, or next second. As long as you're not moving too fast, as long as you can get some of the signal you're probably fine.
However, if the signal from the jammers is millions of times stronger than the signal from the satellites (which is entirely possible and probably even likely) it's probable that your receiver will *never* get any valid data from the satellites.
Any signal from a satellite is going to be very weak -- the satallite is a long way away, our atmosphere attenuates the signals somewhat (which does depend on the frequency), and they cannot transmit with very much power to begin with (because they have limited solar power, and cooling is difficult to do in space.)
Any signal from a satellite can be jammed from the ground just by pumping a few thousand (or more) watts into that frequency in the general vicinity. This noise would overwhelm the weak signal from the satellite and drown it out.
It's also quite possible that any yahoo with a big dish and a few thousand watts to spare could jam an entire satellite by aiming the dish at the satellite and transmitting a few thousand watts on the the frequencies the satellite uses (especially the uplink frequencies.) This has happened recently and made worldwide news.
(Of course, I imagine that the only reason they never caught (?) the person (organization? government?) responsible is that they were in Cuba. This sort of jamming isn't trivial to track down, but I'm sure that it wouldn't take long.)
I'd expect GPS-type satellites to be more resistant to this sort of jamming (because I imagine that they don't really use uplink frequencies at all) but one could certainly jam the control frequencies (which may or may not be needed often) and one could probably interfere with the transmitter by flooding it with noise on it's own channel (I guess ... my experience with RF electronics is limited.)
I doubt that the government would flood the satellite with noise, however -- I suspect they'd just use equipment to jam the local area.
Still, a full sized car is much much more dangerous than any battlebot allowed by the BattleBot rules, and requires much more care. Merely relying on your PCM radio to protect you from disaster *is not enough*.
Yes, and if you have PCM equipment this is built in. However, it's not enough. If the battery gets pulled loose, your servos will all freeze right where they were, and your failsafes will never activate. Or if a big bump cracks your receiver PC board, same thing. Or if your car rolls over and crushes your receiver ...
This is a very non-standard configuration. Suppose what would happen if your throttle servo arm broke, or the servo broke loose so it was hanging free. Not hard to imagine, as it was almost certainly mickey-moused into place in the first place. This is a better situation than the loss of battery, as you've still got steering and brakes, but it could still be very bad.
Of course it has. And people have been throwing R/C equipment into full scale cars for decades now too. But now it's being suggested to those who really have no experience with this sort of thingIn any event, your average 1/8th scale car doing 80 mph will probably be stopped by a simple barrier of old tires or a curb (it will be pretty to watch though!) The car isn't likely to go far, and even if it did, it's probably only got a few minutes of fuel.
On the other hand, your full scale car will go through that, through a fence, many miles cross country, and perhaps even through a full building -- and keep on going. Depending on the car, it may go well over 100 mph. And there won't be a thing you can do to stop it.
A full scale remote control car requires that much much more care be taken than with your average R/C car, even a high performance one.
I still think the kill switch I suggested is essential. Have it set to kill the power to the distributor, or if you must the fuel pump (though that's not as good, as it would take a while for the engine to die.) Having it be a totally seperate system would allow you to kill things even if the first system was broken -- a car is big and heavy, and it's very likely to be abused, and so and I'd expect lots of failures of the primary control system, from pushing the servos too hard, from physical damage (you'll probably be doing all kinds of crazy things with the car) and from not being mounted properly.