. . . but I suspect ultimately of little practical value. Having done quite a bit of RF scanning on the WiFi bands in one of their listed cities (San Francisco) I've seen first hand how signals behave in that dense urban environment.
GPS and WAAS operate on time signals and highly accurate positioning. Cell towers would be inherently more accurate since thier positions are accurately known and don't change (except under very unusual circumstances.
WiFi nodes come up and down constantly, and their position is rarely going to be accurately known by anyone but the person who installed it - and chances are they're not telling "you" exactly where the node is.
Given "walk around surveying" to map the nodes, it's not really a surprise they have accuracy that's no better than an early 2 channel GPS receiver.
And, as others have pointed out, if I'm in downtown San Francisco (or any other city) I don't need my GPS to tell me I'm at 5th and Townsend. For directions there's Mapquest, Google, Yahoo Maps, etc...
Interesting technology. But it sounds more like something a hobbiest would come up with than business.
In other words, they'd have to be at least 12 miles from shore, and possibly (depending on who's doing the interpretation) over 200.
Also, as far as I'm aware, the ship will have to be flagged somewhere, which means that it's effectively that country's territory when in international waters.
The Mech vs Tank discussion is one that I've been into too many times to count. Bottom line is Mecha are cool to look at, but inherently too complex to be especially useful on the battlefield. Those knees are going to be inherently more fragile than a tank's suspension, and the point loading on the feet will be higher than with tracks.
Now, Toyota's application of "walker" technology for aiding the handicapped is exceptionally cool. They've still got to beat the complexity issue (a more or less conventional powered chair is cheaper and less complex) but it IS a clever way to get around the fact that most buildings are designed around people with legs, rather than people with wheels. Power chairs still mostly have trouble with stairs.
I remember doing a paper on Ultra-Light Rail Vehicles back in the early 90's, and that paper (I was an engineering student at the time) was itself based on a system that was being tested in Detroit or Chicago (I forget which.) This "SkyWeb" system is another implementation of that concept.
I honestly wish them luck. While it's a great concept, there's a lot of issues they don't go into (that I could see on the site) such as how a single breakdown can choke a chunk of the system. How they deal with getting cars out for maintenance. Etc., etc., etc.
The article talks about Linux mapping programs that take their feed from GPS via the standard NEMA protocol, not running Linux ON a GPS. (I didn't see any reference in the article to getting the GPS to talk to the Linux box. I'll guess standard Serial, vs USB)
But your point is the same. You don't trust the external chartplotter as much as you trust the GPS device itself. Now, to be honest, in fog I'd rather have radar than GPS. While the GPS receiver can tell me where I am in relation to my marks and place me on a chart (most of the "downloadable maps" are road maps, not charts) it won't tell me about the coastal tanker on anchorage 42.
Worse, I wouldn't want to drag my laptop out on deck when the fog rolls in - and you can be sure I won't be down at the nav station.
They do seem like decent tools for wardriving and geocaching (if you want to lug a laptop) but not for marine navigation.
The issue isn't the data on your card (as you point out the swipe strip already has it all) it's the range RFID gives to that data. With a swipe strip or smart card the officer won't have my information until -after- I have given Officer friendly my card. Unless securely implmented, this gives -anyone- with the apporpriate reader the ability to garner my data from a distance.
Now, if the data is properly encrypted, etc., then the problem's not so severe. But unless and until the implementors can show us a provably secure system, the whole thing still comes under the heading of "Bad Idea (tm)"
BTW, I did catch the LAT/LON, they said it was 40 07 40 and 113 30 29, that would actually show up in China. If you say -113 instead of +113, you get a location in the Deseret Test Center.
Actually, Lat and Lon are measured Ease/West from Greenwich, and North/South of the equater, so the correct syntax would have been 113W by 40N (plus minutes and seconds, of course.)
As I remember it, star charts us a similar nomenclature with degrees east/west from Aries and north/south from the ecliptic.
The display (I wasn't watching, so only have your description here) may have simply omited the pertinant W/N data. They knew which hemisphere it was coming down in, after all.
There's a number of comments on this thread already, but I think you're ultimately right on this. A terrorist can do more damage to a building with a loaded out SUV than he can with a light aircraft. It's a kinetic energy thing. A fully loaded Cessna weighs less than a Toyota Echo (depending on model, of course). We're not going to pursue the other alternatives like arial spraying or dropping leaflets.
A Suburban could -carry- the Cessna and still have room for five passengers and it's own 3 ton mass.
Flying cars will have the same issues. Aircraft need to be relatively light. They're not going to have the mass - and the resultant kinetic energy - of an SUV.
Not that we can expect to actually -see- these things in the near future. Coolness factors or not.
Yes, I caught the reference in your original post, but your example here of stereoscopic vision isn't an example of phased array, but of paralax, as you explain. They are two separate things - though you could certainly combine multiple arrays to give you the same effect.
While I agree that a sophisticated phased array setup for a base station would help with the current issues, it's not an all-in-wonder solution. While it would be great for differentiating between laptops in opposite corners of a room, the angular resolution probably isn't enough to differentiate between a pair of laptops operating in close proximity.
In any case, I'll let it go before it drifts too far off topic.
I've followed this thread, and your followup explanation, and I'm still trying to figure out what you're talking about here. I understand phased arrays, but your explanation doesn't make much sense.
I'm going to go out on a limb here and try and interprete it. If I understand you right, you're talking about using a phased array to differentiate amungst various signals all on the same freq, and signal processing equipment to pull a specific signal out of the noise.
I think that's what you're trying to get at. And yes, you could use a phased array to do that. But there are still a number of problems - like setting up the precise physical configuration (The higher the freq, the tighter tollerances) and the fact that too many signals on the same freq will still hetrodyne and drown each other out.
Conceptionally plausible - using the arrays for directional transmission and reception, but neither practical or especially elegant.
Forget the current legal nightmare of this proposal - just roll with me...
Were that we could...
Why is DNS particularly not well suited for this kind of distribution mechanism?
Because DNS is designed to handle its hierarchical data, not massive amounts of content? The extra fields available in DNS are there fo, well, DNS related stuff.
Seems to me that if the RIAA wanted to distribute their movies via broadband providers (an inevitability, I'm afraid) the biggest problem would be dealing with BANDWIDTH.
I know you meant the MPAA, not the RIAA, but I think their biggest problem will be letting go of their deep seated need for control, rather than bandwidth. They can afford the pipe. And I, for one, would be incredibly pissed off to find the RIAA (or any other commercial service) caching their stuff on MY name server.
I always figured that ISPs would have to have some way to cache content locally so their Internet pipes don't get absolutely HAMMERED by all the people viewing the latest flick...
Like, say, USENET?
DNS already has a mature, stable, and lightweight caching mechanism in place. Why not use it?
We do. Millions of times a day. We use it every time we translate a name to an IP number. Looking up, say www.slashdot.org
Honestly, caching content a la DNS might provide a MUCH more efficient content distribution mechanism than, say, BitTorrent.
Highly unlikely. A highly effecient system dedicated to caching content will almost certainly be better than trying to do the same thing with DNS. It's simply not made for it.
Where's the bad part of this idea?
Inefficiency. Load on already stressed servers. Better existing solutions. Should I go on?
Dan's come up with some brilliant ideas over time. Definately A Geek's Geek. But this one sounds a lot more like one of his thought experiments than an actual proposal. Like directly burning CD's over an SSH tunnel...
I agree that cell phones are abused way too often. (Jerks taking useless calls in a theater is a prime example)
Yes, I think we all agree on that.
However, we should never block cell phone reception anywhere.
Bullshit. We should never block reception EVERYwhere I can agree with, but not ever anywhere.
There are some places where it is simply inappropriate to even HAVE a cell phone. Say, an operating suite? Do you REALLY want the RFI, or someone distracted by a call while you're on the slab?
No? Didn't think so.
What if a doctor were to go watch a movie and one of his patients started dying and he needed to be contacted? What if a loved one were in an accident and people were trying to get ahold of you so you could possibly see them before they died?
Honestly? My personal emergency doesn't give me the right to inconvenience 300 other people. If it was ONLY emergency calls, then we could accept it. But it's not. It's crap calls. Blocking the one in a million honest emergencies to block the 99.999% crap?
Where's my wallpaper paste.
There are many scenarios where having cell reception is important.
Yes, there are. There are also many situations where not having cell phone reception is a matter of "enforced common courtesy."
The idea that because we have always on communications means we need always on communications needs to stop.
Just try to use the vibrate or silent mode. I can deal with people forgetting to turn their phones off in a movie (though I myself have the courtesy to turn mine off), as long as they don't yack on them in the theater.
Yes. We agree. But how does that change the fact that MOST people don't bother? Sorry, if Heir Doktor can't be out of touch for a couple of hours, then maybe he shouldn't be going to the theater.
He accepted the responsibility. That doesn't mean he gets to impose it on the rest of us.
No, I don't want a company to waste 10 - 15% of a grant on website marketing. I would, however, expect someone to put at least a couple tenths of a percent into their website, especially when they're trying to sell a PROP from a SciFi Convention costume contest!
They can give you incentives for using plastic, but they cannot refuse to accept cash
Actually, not true. They can refuse to accept cash in a transaction. The Legal Tender statement on a bank note indicates that the Government considers it Money, and will treat it as such, and that it can legaly be considered Money in any transactions. But like with cheques and credit cards, someone can refuse to accept that method of payment.
It may not be very intelligent to refuse cash, but it IS legal.
I may well be far wrong on the details of this case, and Monsanto may well have a legal ground to take some action. As I said, I haven't followed it closely.
You're right about the use of saved vs purchased seed, but the practice is still done. The interesting point you raise about it being like a EULA, leads me to believe they might have a contract violation here, but that doesn't make it a patent infringement. He violated the license agreement, yes? That's different from infringing the patent.
If I understand patents correctly, and can explain my reasoning (sometimes a challenge), he's not infringing their patents. He's not incorporating their patented technology into another product. He's simply re-using their product.
Plants reproduce as a normal function of being plants. Not sure how he's violating their patent by taking their product (plant) and using it for one of the normal uses for said product (eat, make more plants.)
Definate grounds for a breach of contract suit (if he was buying from them) but patent infringement?
Thanks for the clarification. But I still hold that if he's using "salvage" seed they don't have a patent case. At best there -might- be a theft case for "stealing" the salvaged seeds (though if they were blown in, it wouldn't be theft, since it was on his property) or a criminal case if he literaly stole the seed from off the back of a truck or something. But patent?
He's an end user, using the seed product, he's not manufacturing it. Patent protects a manufacturers technology and it's ability to "make the product" safe from competition. The guy may have done an end run around Monsanto's supply line, but he's not infringing their patent.
Obviously, the Canadian courts think otherwise - and I'm not going to dig into the depths of the case, so there may be issues that make my arguments inapplicable to the case.
I haven't followed the case extensively, but as I understand it he was planting seeds that were saved from the previous year's harvest. Something farmers have been doing for, oh, say, 8000 years.
He was not, then, planting Monsanto's canola. He was planting HIS canola. That the Monsanto engineered plants were still viable was not his fault, it was theirs. Arguably, he is not infringing their patents because he either A: has already payed to get the engineered seed, or B: it was non-engineered seed that was polinated by Engineered stock - which is not his fault.
If Monsanto can't keep a lid on their genetic engineering projects, that's their problem. And, if the Greens are to be believed, everyone elses "problem" too.
You really seem to want to emphasize that "wrong" there, eh?
You are right about the carbon cycle. I know how it works. Plants snag CO2 out of the air, use sunlight for energy, release the 02, move the C into their biomass. Animals take in the biomass, burn O2 with C for energy, vent the CO2 back into the atmosphere.
Horribly over-simplified, but I haven't had my coffee yet.
As for "cleaner" I was refering to the -other- combustion byproducts. Methane burns very clean. Water, CO2, and heat. Oil has a lot of other crap in it as well. As for the CO2, there is still a higher localized concentration of CO2 than you'd get with a normal biological carbon cycle process.
Biologicals take time to pull the CO2 out of the atmosphere, and the process is relatively well balanced. Burning Methane from biomass releases the stored Carbon back into the atmosphere at a higher rate than the biologicals pull it back in, thus raising the CO2 levels. The effect would probably be temporary, and localized. Now, that may ultimately not be a bad thing, since the plants will like it, and probably grow faster, bringing it back into equilibrium.
In any case, I'm with you that this is a good technology and ultimately a lot better than using fossil fuels.
Too few people remember that "copyright" was originally two words - implying the right to copy.
The media wants absolute control. Always. And sometimes the sheer audacity of their arguments makes me want to hurl.
Let's hope this bill gtes farther than the last one. The EFF, incidently, has a quicklink to send email to your congresscritter in support of the bill.
First, let me say that I am not making this argument because I agree with the principle. However, I did mention the existance of party lines as an example. Even on a party line, all parties must agree to the recording even though you assume, when you have a party line, that your conversation may not be private.
I understand. Party lines though, are a differnt animal from an open IRC channel. The situation with a party line would be something like me in open channel on one end of the conversation, and someone else on the other on ICQ through a gateway. The channel rules in #party-line are "When Bob and Alice are talking through the gateway, be polite and leave them alone."
There are some specific laws regarding party lines, while IRC, specifically, is not covered by those laws.
Just because technology has outpaced regulation (as it always does) does not give you sufficient cover. Regulators and other governmental authorities have and will argue that you should have checked the law and applied those findings conservatively.
This becomes very tricky when dealing with something like IRC. Who's laws apply? The small network i'm involved with has servers in four countries on three continents. Does the user in New Hampshire get to say "it's illegal for you to log my conversation!" when he's logged into a UK server talking to someone in Vancouver, BC, who's logged into a server in Tasmania?
It might matter to a law enforcement officer in New Hampshire, but you can be assured they'll point to the MOTD and say "The user was warned that his conversation would be logged."
Disclaimers don't help anyone in any situation. No disclaimer absolves complicity.
If my AUP says explicitly that your conversation may (and probably will) be logged, then they can't use "You didn't have my consent!" as a defense in court. My AUP explicitly states that as a condition of using the service, you acknowledge that you are consenting to possible logging.
Again, don't assume that I support the notion that logs are the same thing as a tape recording. I'm just noting that there are states that have the legal authority to make this case stick and folks should be aware of the risk.
No worries. I understand the case you're making here. The example I posted was there expressly to cover the instance of someone possibly using logs from that network in court. It has not, to my knowledge, ever been tested. But it's actually there more to assist Law Enforcement than it is to give anyone an excuse.
Roughly the same as hopping on the Party Line and stating to everyone listening, loudly, "I AM recording. If you don't agree, leave now." It's unforgivably rude in a party line setting, but if they stay they can't use the excuse that they didn't know. Of course, some defense lawyer will still come in and say "It doesn't matter that these logs show Mister Flaegilsnut was clearly soliciting sex from a twelve year old in a crowded, open, channel on IRC. He didn't consent to having his activity logged!" in spite of the AUP statement that if he is there, his conversation WILL be logged.
Yes, I expect it was fixed phase shift, which is correct for that- for a physically steered antenna. That says nothing about the general case of phased element array, which includes active elements with electronic phase shifting; the plasma reflector is an example of that. That's how you can arrange for electronic streering.
Actually, no, but it was designed for mobile operation since I can get better results with other systems.
And which is it? Is the plasma antenna a reflector or a phased array? They're not the same thing. The system imaged (which is where this whole thread started) is a reflector, not a phased array. I suppose they could be using the plasma to change the focus, but the plasma isn't acting as a transmit or receive element - it's acting as a reflector.
Correct! I wasn't protecting the wireless part of the network, as you more or less cannot (short of Tempest shielding). I was protecting corporate data. As a rule of thumb anyone can use the airwaves under FCC rules. I did make very sure that the wireless network didn't provide internet access, or any other services; so whilst outsiders ('Eve') could in theory have connected to the Wireless LAN from outside the building (difficult since the building was a weak approximation to a Faraday cage, but possible with an antenna of high enough gain), it wouldn't really do 'Eve' much good. The only exception was a direct attack on the clients themselves- I deployed personal firewalls for those; and the security turned out to be the same or better than when the same clients were connected to corporate LAN over the internet.
Well, you can provide some protection for the wireless part of the network by encrypting your wireless traffic and keeping your signals as well contained as possible. Which is what we've both described. Only for some reason you think my version is "ghastly." I left out the details on the authentication and internal connections, remember? Ultimately, I suspect our systems are quite similar under the hood - though I think I put more effort into signal containment than you did.
And no, the rule of thumb is not "anyone can use the airwaves under FCC rules." In fact, the FCC is quite strict about what parts of the spectrum you can use with or without a license, at what power levels, and with what equipment. The fines can be pretty severe for operating unlicensed in licensed bands, and can include jail time. The rules for Part 15 devices (under which Wireless falls) are very restrictive.
As for Eve, I think our end results are more or less the same, with slightly different technical details.
The phase difference between the signal received at the middle of an antenna from either side of the antenna is slightly different from a nearby spherical source to that of a spherical source at infinity (plane wave). The wider the antenna is, the bigger the effect. You need a big antenna, but it can be flat and out the way- up against a wall for example. I simply can't be bothered to explain how you can do this- if you don't believe it can be done, or it's too complex.
Wolf, please go back through the thread and notice where I said that you could get range from a suitably large array by using different sections to triangulate. You don't need to "explain this" since I did myself several messages back.
The point is that you're not getting range simply from phase. You're getting range by triangulation using different sets of elements on your "large array."
If you're using phase difference between "right, left, and middle" you are using three points of compareson which gives you two lines of position (or more if you want), from which you are triangulating the position of the emitter - which is what I've been saying all along.
I think you'll probably agree that the idea of using a wall-sized phased aray (plasma or otherwise) to "add security" t
I've heard the argument about Two Party consent for IRC logging before, and it doesn't hold water. First, there is no expectation of privacy on an open channel discussion like IRC. (private message may enatil a different assumption) Second, logging is a "normal part of most client applications." Thus, not only do you have no expectation of privacy, you have every reasonable expectation that your conversation will be logged by someone in the channel. Third, at least some servers have a disclaimer in their MOTD stating that all traffic is subject to logging, and by connecting you acknowledge the fact.
For example:
--- - POSTED DISCLAIMER - Internet Relay Chat is an open communication system --- - and may be subject to random monitoring by your ISP, our ISP, various and --- - sundry carriers in between, Martians, Spooks, and god only knows what or --- - who else, as well as Quality Control checks by admins or staff for any of --- - a hundred valid reasons. If you are sending clear text traffic, you can --- - have no reasonable expectation of privacy, and by connecting and using an --- - IRC server, you acknowledge that simple fact.
(Bold emphasis isn't in the actual MOTD)
So, basically, the logging is covered by the AUP of the service. You could not read the MOTD and claim ignorance, but it wouldn't excuse you from the net's AUP.
Of course, that doesn't explain why the FBI and the Secret Service (Hmmm . . . SS . . . how appropriate) are reacting like pricks about the requests. I guess the concept of "Probabl cause" no longer applies.
Utter coddswallop. Neither the receive, nor transmit function works unless you have correct phase shift at each emitter. That's the whole point of a phased array. That's where the name "phased element array" comes from. If you have no phase shift then your antenna will work extremely poorly if at all.
You know, most of the antennas I've built, including the phased array for fox hunting, work quite well. Transmit and receive functions don't work without proper phase shift? Really? Amazing. So I suppose I'll have to explain to the Icom that it can't possibly work because the J-Pole out back doesn't have the right phase shift.
I think the fundamental difference here is that you appear to have confused some terms.
No, it has become clear to me that you fundamentally don't understand phased arrays in general.
It seems to me you don't understand RF in general, so I suppose we're even eh?
An ANTENNA is not an ARRAY. Please stop using the terms interchangably.
I mean, you do know about antennas having resonant frequencies, and needing to put your feed at the correct point, right? And that an array is made up of several antennas, each of which may have several elements. That's what an ARRAY is.
You STILL haven't explained how you can get range simply from phase. You've several times explained how you can get range from triangulation, while calling it phase, but NOT from just knowing the phase of the signal.
Honest. I'd really like to see some reference material here - if you have any.
Yeah? So have I. The answer was: firewalls + corporate standard VPN. In your case I certainly hope your encryption wasn't WEP, but I don't particularly care; it sounds ghastly.
As for the corporate VPN and firewalls, that's great. But neither of them are securing the wireless part of your network. Unless, of course, your wireless is completely separate from the corporate LAN (the only configuration that makes sense from what you said) which still leaves the wireless part wide open.
Well, you're assuming that wired is secure- unless you're using Tempest shielding evesdropping is reasonably easy even with wired.
I assume only that wired is inherently more secure than wireless. Wireless interception requires no physical access and is trivial to do remotely.
Tempest monitoring is non-trivial these days. With the level of emissions dropping lower and lower from modern computer systems, the sensitivity and signal processing power required to to electronic eavesdropping is getting higher and higher - read more and more expensive. Besides, a couple of purposefully unshielded machines playing Quake against each other in Demo mode can do a lot to bury your Signal in the Noise.
(I've actually seen that in practice, demonstrated by someone who knew a thing or two about the technique)
If you're hiding from the Three Letter Acronym folks, well, you're pretty much screwed anyway.
Basically, the only way to be absolutely sure your system is secure is to take it off line, break it into small pieces, dump it into a barrel, fill it with concrete, lock the barrel in a safe, take it off shore, drop it over the side, then kill the crew on the way back.
At least that was the consensus at one of the Vendor parties at LISA a couple years back.
I think having multiple arrays scattered around the place is a very good idea anyway. The nice thing about this focusing trick is that they don't need to be phased together, since they independently can calculate distance. Having multiple arrays allows triangulation, and minimises the chances of the base station and clients lining up; which is likely to be the worst case.
You seem really fixated on that distance calculation thing. Anyway . . . Multiple AP's would be the way to go whenever you're trying to secure your wireless network. You're certainly right there. I've actually (in a past life so to speak) been tasked with helping secure a wireless network in an office environment. The solution was A: Encryption. B: Multiple AP's spread to give good coverage of the building's interior with any overlap well inside the perimiter. C: Very careful antenna selection to provide optimal coverage inside, with minimal sensitivity outside the building. D: MAC address filtering (which helps a little, but is still easy to bypass) E: Other stuff I'm not going to talk about here.
And, once again, a simple phased array is not going to give you range, only bearing. If your AP is some sort of multi-array base station, then you could use triangulation between arrays to get your range. But a phased array by itself will not give you range.
It's probably not normally considered like that, but different parts of any antenna are at a different phase; they have a formally linear response to a wave, right?
Not quite. While the voltage and currant will fluctuate across the structure of the antenna in response to a signal, that's not what matters to your receiver. Your signal processing does not happen ON the antenna, it happens downstream of the antenna in the receive section of your device (be it your FM Walkman, a wireless network card, or an HF radio).
For a phased array, you can consider each 'active' element of a phased array to have a complex number that is multiplied by the signal that is measured at that point. The output of the array is the sum of these numbers. That forms a spatial filter. By calculating the complex number based on the speed of light delay you can (theoretically) focus the array onto a particular point in space by adjusting the phase/amplification in that way. The maths is trivial; in principle.
Ummmm. . . I'm not entirely sure where you're trying to go here. At the surface, where it matters, it's not as complicated as you're making it sound.
Working on the recive end - since that's what you are using to get a direction on a remote emitter. Transmit FROM the array is not important a
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. . . but I suspect ultimately of little practical value. Having done quite a bit of RF scanning on the WiFi bands in one of their listed cities (San Francisco) I've seen first hand how signals behave in that dense urban environment.
GPS and WAAS operate on time signals and highly accurate positioning. Cell towers would be inherently more accurate since thier positions are accurately known and don't change (except under very unusual circumstances.
WiFi nodes come up and down constantly, and their position is rarely going to be accurately known by anyone but the person who installed it - and chances are they're not telling "you" exactly where the node is.
Given "walk around surveying" to map the nodes, it's not really a surprise they have accuracy that's no better than an early 2 channel GPS receiver.
And, as others have pointed out, if I'm in downtown San Francisco (or any other city) I don't need my GPS to tell me I'm at 5th and Townsend. For directions there's Mapquest, Google, Yahoo Maps, etc...
Interesting technology. But it sounds more like something a hobbiest would come up with than business.
"International waters" don't start three miles off-shore. The US maritime claims are as follows:
Maritime claims:
territorial sea: 12 nm
contiguous zone: 24 nm
exclusive economic zone: 200 nm
continental shelf: not specified
In other words, they'd have to be at least 12 miles from shore, and possibly (depending on who's doing the interpretation) over 200.
Also, as far as I'm aware, the ship will have to be flagged somewhere, which means that it's effectively that country's territory when in international waters.
Someones tax man will find them.
The Mech vs Tank discussion is one that I've been into too many times to count. Bottom line is Mecha are cool to look at, but inherently too complex to be especially useful on the battlefield. Those knees are going to be inherently more fragile than a tank's suspension, and the point loading on the feet will be higher than with tracks.
Now, Toyota's application of "walker" technology for aiding the handicapped is exceptionally cool. They've still got to beat the complexity issue (a more or less conventional powered chair is cheaper and less complex) but it IS a clever way to get around the fact that most buildings are designed around people with legs, rather than people with wheels. Power chairs still mostly have trouble with stairs.
I remember doing a paper on Ultra-Light Rail Vehicles back in the early 90's, and that paper (I was an engineering student at the time) was itself based on a system that was being tested in Detroit or Chicago (I forget which.) This "SkyWeb" system is another implementation of that concept.
I honestly wish them luck. While it's a great concept, there's a lot of issues they don't go into (that I could see on the site) such as how a single breakdown can choke a chunk of the system. How they deal with getting cars out for maintenance. Etc., etc., etc.
The article talks about Linux mapping programs that take their feed from GPS via the standard NEMA protocol, not running Linux ON a GPS. (I didn't see any reference in the article to getting the GPS to talk to the Linux box. I'll guess standard Serial, vs USB)
But your point is the same. You don't trust the external chartplotter as much as you trust the GPS device itself. Now, to be honest, in fog I'd rather have radar than GPS. While the GPS receiver can tell me where I am in relation to my marks and place me on a chart (most of the "downloadable maps" are road maps, not charts) it won't tell me about the coastal tanker on anchorage 42.
Worse, I wouldn't want to drag my laptop out on deck when the fog rolls in - and you can be sure I won't be down at the nav station.
They do seem like decent tools for wardriving and geocaching (if you want to lug a laptop) but not for marine navigation.
The issue isn't the data on your card (as you point out the swipe strip already has it all) it's the range RFID gives to that data. With a swipe strip or smart card the officer won't have my information until -after- I have given Officer friendly my card. Unless securely implmented, this gives -anyone- with the apporpriate reader the ability to garner my data from a distance.
Now, if the data is properly encrypted, etc., then the problem's not so severe. But unless and until the implementors can show us a provably secure system, the whole thing still comes under the heading of "Bad Idea (tm)"
An expensive, bad idea, at that.
BTW, I did catch the LAT/LON, they said it was 40 07 40 and 113 30 29, that would actually show up in China. If you say -113 instead of +113, you get a location in the Deseret Test Center.
Actually, Lat and Lon are measured Ease/West from Greenwich, and North/South of the equater, so the correct syntax would have been 113W by 40N (plus minutes and seconds, of course.)
As I remember it, star charts us a similar nomenclature with degrees east/west from Aries and north/south from the ecliptic.
The display (I wasn't watching, so only have your description here) may have simply omited the pertinant W/N data. They knew which hemisphere it was coming down in, after all.
There's a number of comments on this thread already, but I think you're ultimately right on this. A terrorist can do more damage to a building with a loaded out SUV than he can with a light aircraft. It's a kinetic energy thing. A fully loaded Cessna weighs less than a Toyota Echo (depending on model, of course). We're not going to pursue the other alternatives like arial spraying or dropping leaflets.
A Suburban could -carry- the Cessna and still have room for five passengers and it's own 3 ton mass.
Flying cars will have the same issues. Aircraft need to be relatively light. They're not going to have the mass - and the resultant kinetic energy - of an SUV.
Not that we can expect to actually -see- these things in the near future. Coolness factors or not.
Yes, I caught the reference in your original post, but your example here of stereoscopic vision isn't an example of phased array, but of paralax, as you explain. They are two separate things - though you could certainly combine multiple arrays to give you the same effect.
While I agree that a sophisticated phased array setup for a base station would help with the current issues, it's not an all-in-wonder solution. While it would be great for differentiating between laptops in opposite corners of a room, the angular resolution probably isn't enough to differentiate between a pair of laptops operating in close proximity.
In any case, I'll let it go before it drifts too far off topic.
I've followed this thread, and your followup explanation, and I'm still trying to figure out what you're talking about here. I understand phased arrays, but your explanation doesn't make much sense.
I'm going to go out on a limb here and try and interprete it. If I understand you right, you're talking about using a phased array to differentiate amungst various signals all on the same freq, and signal processing equipment to pull a specific signal out of the noise.
I think that's what you're trying to get at. And yes, you could use a phased array to do that. But there are still a number of problems - like setting up the precise physical configuration (The higher the freq, the tighter tollerances) and the fact that too many signals on the same freq will still hetrodyne and drown each other out.
Conceptionally plausible - using the arrays for directional transmission and reception, but neither practical or especially elegant.
Forget the current legal nightmare of this proposal - just roll with me...
Were that we could...
Why is DNS particularly not well suited for this kind of distribution mechanism?
Because DNS is designed to handle its hierarchical data, not massive amounts of content? The extra fields available in DNS are there fo, well, DNS related stuff.
Seems to me that if the RIAA wanted to distribute their movies via broadband providers (an inevitability, I'm afraid) the biggest problem would be dealing with BANDWIDTH.
I know you meant the MPAA, not the RIAA, but I think their biggest problem will be letting go of their deep seated need for control, rather than bandwidth. They can afford the pipe. And I, for one, would be incredibly pissed off to find the RIAA (or any other commercial service) caching their stuff on MY name server.
I always figured that ISPs would have to have some way to cache content locally so their Internet pipes don't get absolutely HAMMERED by all the people viewing the latest flick...
Like, say, USENET?
DNS already has a mature, stable, and lightweight caching mechanism in place. Why not use it?
We do. Millions of times a day. We use it every time we translate a name to an IP number. Looking up, say www.slashdot.org
Honestly, caching content a la DNS might provide a MUCH more efficient content distribution mechanism than, say, BitTorrent.
Highly unlikely. A highly effecient system dedicated to caching content will almost certainly be better than trying to do the same thing with DNS. It's simply not made for it.
Where's the bad part of this idea?
Inefficiency. Load on already stressed servers. Better existing solutions. Should I go on?
Dan's come up with some brilliant ideas over time. Definately A Geek's Geek. But this one sounds a lot more like one of his thought experiments than an actual proposal. Like directly burning CD's over an SSH tunnel...
I agree that cell phones are abused way too often. (Jerks taking useless calls in a theater is a prime example)
Yes, I think we all agree on that.
However, we should never block cell phone reception anywhere.
Bullshit. We should never block reception EVERYwhere I can agree with, but not ever anywhere.
There are some places where it is simply inappropriate to even HAVE a cell phone. Say, an operating suite? Do you REALLY want the RFI, or someone distracted by a call while you're on the slab?
No? Didn't think so.
What if a doctor were to go watch a movie and one of his patients started dying and he needed to be contacted? What if a loved one were in an accident and people were trying to get ahold of you so you could possibly see them before they died?
Honestly? My personal emergency doesn't give me the right to inconvenience 300 other people. If it was ONLY emergency calls, then we could accept it. But it's not. It's crap calls. Blocking the one in a million honest emergencies to block the 99.999% crap?
Where's my wallpaper paste.
There are many scenarios where having cell reception is important.
Yes, there are. There are also many situations where not having cell phone reception is a matter of "enforced common courtesy."
The idea that because we have always on communications means we need always on communications needs to stop.
Just try to use the vibrate or silent mode. I can deal with people forgetting to turn their phones off in a movie (though I myself have the courtesy to turn mine off), as long as they don't yack on them in the theater.
Yes. We agree. But how does that change the fact that MOST people don't bother? Sorry, if Heir Doktor can't be out of touch for a couple of hours, then maybe he shouldn't be going to the theater.
He accepted the responsibility. That doesn't mean he gets to impose it on the rest of us.
No, I don't want a company to waste 10 - 15% of a grant on website marketing. I would, however, expect someone to put at least a couple tenths of a percent into their website, especially when they're trying to sell a PROP from a SciFi Convention costume contest!
Not even an especially convincing prop at that...
They can give you incentives for using plastic, but they cannot refuse to accept cash
Actually, not true. They can refuse to accept cash in a transaction. The Legal Tender statement on a bank note indicates that the Government considers it Money, and will treat it as such, and that it can legaly be considered Money in any transactions. But like with cheques and credit cards, someone can refuse to accept that method of payment.
It may not be very intelligent to refuse cash, but it IS legal.
I may well be far wrong on the details of this case, and Monsanto may well have a legal ground to take some action. As I said, I haven't followed it closely.
You're right about the use of saved vs purchased seed, but the practice is still done. The interesting point you raise about it being like a EULA, leads me to believe they might have a contract violation here, but that doesn't make it a patent infringement. He violated the license agreement, yes? That's different from infringing the patent.
If I understand patents correctly, and can explain my reasoning (sometimes a challenge), he's not infringing their patents. He's not incorporating their patented technology into another product. He's simply re-using their product.
Plants reproduce as a normal function of being plants. Not sure how he's violating their patent by taking their product (plant) and using it for one of the normal uses for said product (eat, make more plants.)
Definate grounds for a breach of contract suit (if he was buying from them) but patent infringement?
Thanks for the clarification. But I still hold that if he's using "salvage" seed they don't have a patent case. At best there -might- be a theft case for "stealing" the salvaged seeds (though if they were blown in, it wouldn't be theft, since it was on his property) or a criminal case if he literaly stole the seed from off the back of a truck or something. But patent?
He's an end user, using the seed product, he's not manufacturing it. Patent protects a manufacturers technology and it's ability to "make the product" safe from competition. The guy may have done an end run around Monsanto's supply line, but he's not infringing their patent.
Obviously, the Canadian courts think otherwise - and I'm not going to dig into the depths of the case, so there may be issues that make my arguments inapplicable to the case.
I still feel it sets a bad precedent.
I haven't followed the case extensively, but as I understand it he was planting seeds that were saved from the previous year's harvest. Something farmers have been doing for, oh, say, 8000 years.
He was not, then, planting Monsanto's canola. He was planting HIS canola. That the Monsanto engineered plants were still viable was not his fault, it was theirs. Arguably, he is not infringing their patents because he either A: has already payed to get the engineered seed, or B: it was non-engineered seed that was polinated by Engineered stock - which is not his fault.
If Monsanto can't keep a lid on their genetic engineering projects, that's their problem. And, if the Greens are to be believed, everyone elses "problem" too.
You really seem to want to emphasize that "wrong" there, eh?
.
You are right about the carbon cycle. I know how it works. Plants snag CO2 out of the air, use sunlight for energy, release the 02, move the C into their biomass. Animals take in the biomass, burn O2 with C for energy, vent the CO2 back into the atmosphere.
Horribly over-simplified, but I haven't had my coffee yet.
As for "cleaner" I was refering to the -other- combustion byproducts. Methane burns very clean. Water, CO2, and heat. Oil has a lot of other crap in it as well. As for the CO2, there is still a higher localized concentration of CO2 than you'd get with a normal biological carbon cycle process.
Biologicals take time to pull the CO2 out of the atmosphere, and the process is relatively well balanced. Burning Methane from biomass releases the stored Carbon back into the atmosphere at a higher rate than the biologicals pull it back in, thus raising the CO2 levels. The effect would probably be temporary, and localized. Now, that may ultimately not be a bad thing, since the plants will like it, and probably grow faster, bringing it back into equilibrium.
In any case, I'm with you that this is a good technology and ultimately a lot better than using fossil fuels.
Need . . . more . . . coffee . .
So what's the waste generated from this?
CO2, waste heat, and "digested" solids - which are still effective as fertilizer (though not as rich).
Is it considered "clean" energy?
Cleaner than oil-fired plants, but there is still the CO2 output.
Is used poop as good at fertilizing as new poop?
Depends on the remaining nutrient levels, but it is still usable, yes.
Would it work with human poop? Can I build a small version myself? Are their poop bylaws?
Yes, yes, and yes. There are rural communities in undeveloped countries that use methane produced by the community's waste for cooking and heating.
And most importantly, does it run Linux??
Linux is Open Source. I'm sure someone can port it...
Amen.
Too few people remember that "copyright" was originally two words - implying the right to copy.
The media wants absolute control. Always. And sometimes the sheer audacity of their arguments makes me want to hurl.
Let's hope this bill gtes farther than the last one. The EFF, incidently, has a quicklink to send email to your congresscritter in support of the bill.
First, let me say that I am not making this argument because I agree with the principle. However, I did mention the existance of party lines as an example. Even on a party line, all parties must agree to the recording even though you assume, when you have a party line, that your conversation may not be private.
I understand. Party lines though, are a differnt animal from an open IRC channel. The situation with a party line would be something like me in open channel on one end of the conversation, and someone else on the other on ICQ through a gateway. The channel rules in #party-line are "When Bob and Alice are talking through the gateway, be polite and leave them alone."
There are some specific laws regarding party lines, while IRC, specifically, is not covered by those laws.
Just because technology has outpaced regulation (as it always does) does not give you sufficient cover. Regulators and other governmental authorities have and will argue that you should have checked the law and applied those findings conservatively.
This becomes very tricky when dealing with something like IRC. Who's laws apply? The small network i'm involved with has servers in four countries on three continents. Does the user in New Hampshire get to say "it's illegal for you to log my conversation!" when he's logged into a UK server talking to someone in Vancouver, BC, who's logged into a server in Tasmania?
It might matter to a law enforcement officer in New Hampshire, but you can be assured they'll point to the MOTD and say "The user was warned that his conversation would be logged."
Disclaimers don't help anyone in any situation. No disclaimer absolves complicity.
If my AUP says explicitly that your conversation may (and probably will) be logged, then they can't use "You didn't have my consent!" as a defense in court. My AUP explicitly states that as a condition of using the service, you acknowledge that you are consenting to possible logging.
Again, don't assume that I support the notion that logs are the same thing as a tape recording. I'm just noting that there are states that have the legal authority to make this case stick and folks should be aware of the risk.
No worries. I understand the case you're making here. The example I posted was there expressly to cover the instance of someone possibly using logs from that network in court. It has not, to my knowledge, ever been tested. But it's actually there more to assist Law Enforcement than it is to give anyone an excuse.
Roughly the same as hopping on the Party Line and stating to everyone listening, loudly, "I AM recording. If you don't agree, leave now." It's unforgivably rude in a party line setting, but if they stay they can't use the excuse that they didn't know. Of course, some defense lawyer will still come in and say "It doesn't matter that these logs show Mister Flaegilsnut was clearly soliciting sex from a twelve year old in a crowded, open, channel on IRC. He didn't consent to having his activity logged!" in spite of the AUP statement that if he is there, his conversation WILL be logged.
Enjoy the weekend.
Yes, I expect it was fixed phase shift, which is correct for that- for a physically steered antenna. That says nothing about the general case of phased element array, which includes active elements with electronic phase shifting; the plasma reflector is an example of that. That's how you can arrange for electronic streering.
Actually, no, but it was designed for mobile operation since I can get better results with other systems.
And which is it? Is the plasma antenna a reflector or a phased array? They're not the same thing. The system imaged (which is where this whole thread started) is a reflector, not a phased array. I suppose they could be using the plasma to change the focus, but the plasma isn't acting as a transmit or receive element - it's acting as a reflector.
Correct! I wasn't protecting the wireless part of the network, as you more or less cannot (short of Tempest shielding). I was protecting corporate data. As a rule of thumb anyone can use the airwaves under FCC rules. I did make very sure that the wireless network didn't provide internet access, or any other services; so whilst outsiders ('Eve') could in theory have connected to the Wireless LAN from outside the building (difficult since the building was a weak approximation to a Faraday cage, but possible with an antenna of high enough gain), it wouldn't really do 'Eve' much good. The only exception was a direct attack on the clients themselves- I deployed personal firewalls for those; and the security turned out to be the same or better than when the same clients were connected to corporate LAN over the internet.
Well, you can provide some protection for the wireless part of the network by encrypting your wireless traffic and keeping your signals as well contained as possible. Which is what we've both described. Only for some reason you think my version is "ghastly." I left out the details on the authentication and internal connections, remember? Ultimately, I suspect our systems are quite similar under the hood - though I think I put more effort into signal containment than you did.
And no, the rule of thumb is not "anyone can use the airwaves under FCC rules." In fact, the FCC is quite strict about what parts of the spectrum you can use with or without a license, at what power levels, and with what equipment. The fines can be pretty severe for operating unlicensed in licensed bands, and can include jail time. The rules for Part 15 devices (under which Wireless falls) are very restrictive.
As for Eve, I think our end results are more or less the same, with slightly different technical details.
The phase difference between the signal received at the middle of an antenna from either side of the antenna is slightly different from a nearby spherical source to that of a spherical source at infinity (plane wave). The wider the antenna is, the bigger the effect. You need a big antenna, but it can be flat and out the way- up against a wall for example. I simply can't be bothered to explain how you can do this- if you don't believe it can be done, or it's too complex.
Wolf, please go back through the thread and notice where I said that you could get range from a suitably large array by using different sections to triangulate. You don't need to "explain this" since I did myself several messages back.
The point is that you're not getting range simply from phase. You're getting range by triangulation using different sets of elements on your "large array."
If you're using phase difference between "right, left, and middle" you are using three points of compareson which gives you two lines of position (or more if you want), from which you are triangulating the position of the emitter - which is what I've been saying all along.
I think you'll probably agree that the idea of using a wall-sized phased aray (plasma or otherwise) to "add security" t
I've heard the argument about Two Party consent for IRC logging before, and it doesn't hold water. First, there is no expectation of privacy on an open channel discussion like IRC. (private message may enatil a different assumption) Second, logging is a "normal part of most client applications." Thus, not only do you have no expectation of privacy, you have every reasonable expectation that your conversation will be logged by someone in the channel. Third, at least some servers have a disclaimer in their MOTD stating that all traffic is subject to logging, and by connecting you acknowledge the fact.
For example:
--- - POSTED DISCLAIMER - Internet Relay Chat is an open communication system
--- - and may be subject to random monitoring by your ISP, our ISP, various and
--- - sundry carriers in between, Martians, Spooks, and god only knows what or
--- - who else, as well as Quality Control checks by admins or staff for any of
--- - a hundred valid reasons. If you are sending clear text traffic, you can
--- - have no reasonable expectation of privacy, and by connecting and using an
--- - IRC server, you acknowledge that simple fact.
(Bold emphasis isn't in the actual MOTD)
So, basically, the logging is covered by the AUP of the service. You could not read the MOTD and claim ignorance, but it wouldn't excuse you from the net's AUP.
Of course, that doesn't explain why the FBI and the Secret Service (Hmmm . . . SS . . . how appropriate) are reacting like pricks about the requests. I guess the concept of "Probabl cause" no longer applies.
*ROTFLU!*
Utter coddswallop. Neither the receive, nor transmit function works unless you have correct phase shift at each emitter. That's the whole point of a phased array. That's where the name "phased element array" comes from. If you have no phase shift then your antenna will work extremely poorly if at all.
You know, most of the antennas I've built, including the phased array for fox hunting, work quite well. Transmit and receive functions don't work without proper phase shift? Really? Amazing. So I suppose I'll have to explain to the Icom that it can't possibly work because the J-Pole out back doesn't have the right phase shift.
I think the fundamental difference here is that you appear to have confused some terms.
No, it has become clear to me that you fundamentally don't understand phased arrays in general.
It seems to me you don't understand RF in general, so I suppose we're even eh?
An ANTENNA is not an ARRAY. Please stop using the terms interchangably.
I mean, you do know about antennas having resonant frequencies, and needing to put your feed at the correct point, right? And that an array is made up of several antennas, each of which may have several elements. That's what an ARRAY is.
You STILL haven't explained how you can get range simply from phase. You've several times explained how you can get range from triangulation, while calling it phase, but NOT from just knowing the phase of the signal.
Honest. I'd really like to see some reference material here - if you have any.
Yeah? So have I. The answer was: firewalls + corporate standard VPN. In your case I certainly hope your encryption wasn't WEP, but I don't particularly care; it sounds ghastly.
As for the corporate VPN and firewalls, that's great. But neither of them are securing the wireless part of your network. Unless, of course, your wireless is completely separate from the corporate LAN (the only configuration that makes sense from what you said) which still leaves the wireless part wide open.
Adieu
Well, you're assuming that wired is secure- unless you're using Tempest shielding evesdropping is reasonably easy even with wired.
I assume only that wired is inherently more secure than wireless. Wireless interception requires no physical access and is trivial to do remotely.
Tempest monitoring is non-trivial these days. With the level of emissions dropping lower and lower from modern computer systems, the sensitivity and signal processing power required to to electronic eavesdropping is getting higher and higher - read more and more expensive. Besides, a couple of purposefully unshielded machines playing Quake against each other in Demo mode can do a lot to bury your Signal in the Noise.
(I've actually seen that in practice, demonstrated by someone who knew a thing or two about the technique)
If you're hiding from the Three Letter Acronym folks, well, you're pretty much screwed anyway.
Basically, the only way to be absolutely sure your system is secure is to take it off line, break it into small pieces, dump it into a barrel, fill it with concrete, lock the barrel in a safe, take it off shore, drop it over the side, then kill the crew on the way back.
At least that was the consensus at one of the Vendor parties at LISA a couple years back.
I think having multiple arrays scattered around the place is a very good idea anyway. The nice thing about this focusing trick is that they don't need to be phased together, since they independently can calculate distance. Having multiple arrays allows triangulation, and minimises the chances of the base station and clients lining up; which is likely to be the worst case.
You seem really fixated on that distance calculation thing. Anyway . . . Multiple AP's would be the way to go whenever you're trying to secure your wireless network. You're certainly right there. I've actually (in a past life so to speak) been tasked with helping secure a wireless network in an office environment. The solution was A: Encryption. B: Multiple AP's spread to give good coverage of the building's interior with any overlap well inside the perimiter. C: Very careful antenna selection to provide optimal coverage inside, with minimal sensitivity outside the building. D: MAC address filtering (which helps a little, but is still easy to bypass) E: Other stuff I'm not going to talk about here.
And, once again, a simple phased array is not going to give you range, only bearing. If your AP is some sort of multi-array base station, then you could use triangulation between arrays to get your range. But a phased array by itself will not give you range.
It's probably not normally considered like that, but different parts of any antenna are at a different phase; they have a formally linear response to a wave, right?
Not quite. While the voltage and currant will fluctuate across the structure of the antenna in response to a signal, that's not what matters to your receiver. Your signal processing does not happen ON the antenna, it happens downstream of the antenna in the receive section of your device (be it your FM Walkman, a wireless network card, or an HF radio).
For a phased array, you can consider each 'active' element of a phased array to have a complex number that is multiplied by the signal that is measured at that point. The output of the array is the sum of these numbers. That forms a spatial filter. By calculating the complex number based on the speed of light delay you can (theoretically) focus the array onto a particular point in space by adjusting the phase/amplification in that way. The maths is trivial; in principle.
Ummmm. . . I'm not entirely sure where you're trying to go here. At the surface, where it matters, it's not as complicated as you're making it sound.
Working on the recive end - since that's what you are using to get a direction on a remote emitter. Transmit FROM the array is not important a