You could ask the same of regular speakers - what happens if someone cranks up the amp and points it at people at close range? Does it cause damage to people's hearing?
Oh, wait. This is happening all the time in dance clubs - they always play at levels that cause irreversible hearing damage.
IIRC, this device uses levels similar to medical ultrasound but since it's not in direct contact with the body the coupling loss is huge (tens of dbs).
Zen Research has developed a technology that reads the disk using 7 beams in parallel, achieving high throughput without spinning the disk at ridiculous speeds.
It has been licensed by several companies including Kenwood that used it to produce an amazing 72x drive.
You can always trust Rober Forward to come up with a good idea.
See his Terminator Tether page. It's a great way to bring down an orbiting mass without actually having to carry the mass of fuel that would be required for a deorbiting burn.
Which would you rather have as new owner of PayPal
on
Ebay buys PayPal
·
· Score: 2
According to the description in the article the algorithm has random seeding, mutations, a ranking function and survival of the fittest - but it doesn't have genetic exchange. New layouts are not chosen as combinations of two or more existing layouts.
Genetic exchange is very important for rapid evolution. The Earth was just a big bacterial soup for two billion years. Then sex was invented and then things started to get more interesting very quickly.
A NASA engineer and his manager were asked to estimate the chances of failure of a critical component in the shuttle engine. This was a component that could cause loss of vessel and crew if it failed.
The engineer and manager's estimates differed by two orders of magnitude.
You're right. There is a difference in the approach to risk between NASA and the russians. I believe their managers are not that far out of touch with reality. They accept the fact that space exploration is dangerous and spend more of their time preventing the next disaster than covering their asses. I am sure that russian engineers and managers have just as much respect for human life as americans and they do their best to ensure the safety of their cosmonauts within the costraints imposed by physics, engineering and, let's face it, budgets.
Safety reports spanning millions of pages printed on tons of dead trees do not make a system safe. They just help managers to live in denial.
With current silicon integration levels there is no real reason why SCSI should be more expensive than ATA. They could have just merged them and perhaps emulated braindead ATA on top of SCSI to keep compatibility or something if anyone really wants to.
I'm pretty sure the only reason they keep the difference is to be able to charge more from people building servers. It's purely a marketing and price positioning decision.
Predictable ISNs are only a problem against a machine which has been configured to allow another machine privileges based solely on that second's machine IP address.
Are you willing to bet that this is the *only* kind of attack possible using sequence number prediction? Someone with a sick imagination may find other novel and destructive uses for it.
The solution proposed in RFC1948 is to bias the sequence number by a hash of a secret value and the source IP address and port numbers.
This means that even if the underlying random number generator is very poor or not random at all an attacker will not be able to guess your sequence numbers for spoofing attacks. You will still be able to easily guess *your own* ISNs for subsequent connections so the system will appear to be vulnerable in tests like the one in this article. Some of the systems with poor 'attack feasibility' ratings in the article may in fact implement this mechanism.
It seems that the broadcasters are much more interested in using the digital technology to transmits six channels in the same bandwidth formerly used for one than to transmit one high definition channel.
...or only expect it to work in areas with very dense node populations (the urban WiFi solution).
This might be true if the system relied entirely on peer-to-peer routing.
Let's say that the system has enough fixed base stations to get full coverage of the operating area. The only problem is capacity - it can't support more than a certain density of terminals per square mile. The standard approach to this problem in cellular networks is to add more base stations to reduce the cell radius leading to a reduction in transmission power and a better frequency reuse factor. With this system whenever there is a high density of terminals it compensates automatically by using a number of short-range low-power hops to get to the nearest base station instead of one high-powered hop that wastes frequency capacity over a large area.
Basic truth: for reliable low-power communication, at least one end of the link needs to be well-sited.
This "basic truth" is true only assuming the link has only two ends and therefore just one communication path. If this path is degraded by fading or shadowing you must have adequate power margins to cope with it.
On an adaptive mesh network you have multiple routes through repeaters to the nearest base station. At least some of those paths should have favorable reception conditions and be capable of running at very low power.
It may seem unreliable to trust statistics but phone networks have done so for ages. If you are stuck without enough repeaters your terminal can jack up its power all the way up to normal maximum power levels of cellular phones (a few hundred milliwatts) and talk directly to the base station. But wait - this wastes frequency capacity over a larger area, right? Not a problem. If you don't have neighbors to carry your traffic it means that they don't need this capacity at this time!
Anyways, why not modify this so low-power, discrete antennas can do the job instead of other phones? Putting a small repeater every few light poles on the highway or along streets in areas of poor reception would vastly improve reception (if not coverage) and avoid the need for as many towers.
You have just described the Metricom Ricochet network (RIP).
There is plenty of moving mass in the universe. Has anyone measured a gravitomagnetic effect?
The problem is that there is either big mass moving slowly or small mass moving fast. You need a big mass to move fast to get a measurable effect. A supernova in our galaxy should generate a gravitomagnetic field big enough to measure with current sensors. On average, they happens once every few hundred years. We just need to wait...
IIRC, the gravitomagnetic field has been measured indirectly by observing the slowdown of a rapidly rotating binary star. The rate of deceleration not accounted for by other effects matched the predicted amount of energy it was supposed to lose by radiating gravitation waves with very good accuracy.
Capitalism suffers from exactly the same problem as communism: it works great in theory, because it assumes that people are basically good and honest and will cooperate with the spirit as well as the letter of the system.
Oh, that's not the real problem. Capitalism works just fine. It's corporatism that sucks.
If the Gibralter Bridge is ever built, I predict it to be an incredible boost to the economies of both Europe and Africa. Industry in Europe could gain by getting cheap labor in Africa, while nations in Africa will receive heavy investments - Improving their infrastructure. Surely it would be a Win-Win situation for both Africa and Europe.
Perhaps if Carthago had triumphed over Rome it would have been the other way around...
I think active vibration dampening has already been demonstrated in diesel engines and it cuts down on noise and, perhaps more importantly, reduces wear.
How about an active automobile suspension that also has a millimeter wave radar looking forward to anticipate bumps and potholes?
The article talks about using the underground conduits to pass communication cables in addition to the electric wires, not about transmitting data over the power lines.
Powerline communication is nice, but it can't quite compete with fiber.
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You could ask the same of regular speakers - what happens if someone cranks up the amp and points it at people at close range? Does it cause damage to people's hearing?
Oh, wait. This is happening all the time in dance clubs - they always play at levels that cause irreversible hearing damage.
IIRC, this device uses levels similar to medical ultrasound but since it's not in direct contact with the body the coupling loss is huge (tens of dbs).
Zen Research has developed a technology that reads the disk using 7 beams in parallel, achieving high throughput without spinning the disk at ridiculous speeds.
It has been licensed by several companies including Kenwood that used it to produce an amazing 72x drive.
Some portable CD/MP3 players also have the ability to play VideoCD. Here's an example.
I guess some people have faulty irony detector.
You can always trust Rober Forward to come up with a good idea.
See his Terminator Tether page. It's a great way to bring down an orbiting mass without actually having to carry the mass of fuel that would be required for a deorbiting burn.
Microsoft
AOL
eBay
Is eBay the lesser of three evils?
According to the description in the article the algorithm has random seeding, mutations, a ranking function and survival of the fittest - but it doesn't have genetic exchange. New layouts are not chosen as combinations of two or more existing layouts.
Genetic exchange is very important for rapid evolution. The Earth was just a big bacterial soup for two billion years. Then sex was invented and then things started to get more interesting very quickly.
I'm pretty sure they do. That's why their estimate is closer to Zubrin's estimates ($20-$30 billion) than to NASA's ($450 billion).
A NASA engineer and his manager were asked to estimate the chances of failure of a critical component in the shuttle engine. This was a component that could cause loss of vessel and crew if it failed.
The engineer and manager's estimates differed by two orders of magnitude.
You're right. There is a difference in the approach to risk between NASA and the russians. I believe their managers are not that far out of touch with reality. They accept the fact that space exploration is dangerous and spend more of their time preventing the next disaster than covering their asses. I am sure that russian engineers and managers have just as much respect for human life as americans and they do their best to ensure the safety of their cosmonauts within the costraints imposed by physics, engineering and, let's face it, budgets.
Safety reports spanning millions of pages printed on tons of dead trees do not make a system safe. They just help managers to live in denial.
With current silicon integration levels there is no real reason why SCSI should be more expensive than ATA. They could have just merged them and perhaps emulated braindead ATA on top of SCSI to keep compatibility or something if anyone really wants to.
I'm pretty sure the only reason they keep the difference is to be able to charge more from people building servers. It's purely a marketing and price positioning decision.
Predictable ISNs are only a problem against a machine which has been configured to allow another machine privileges based solely on that second's machine IP address.
Are you willing to bet that this is the *only* kind of attack possible using sequence number prediction? Someone with a sick imagination may find other novel and destructive uses for it.
In fact, I can already think of some...
The solution proposed in RFC1948 is to bias the sequence number by a hash of a secret value and the source IP address and port numbers.
This means that even if the underlying random number generator is very poor or not random at all an attacker will not be able to guess your sequence numbers for spoofing attacks. You will still be able to easily guess *your own* ISNs for subsequent connections so the system will appear to be vulnerable in tests like the one in this article. Some of the systems with poor 'attack feasibility' ratings in the article may in fact implement this mechanism.
With anti-aliasing pictures may look good enough or better even at lower resolutions leading to higher frame rate.
Optimizing for (subjective quality)*(framerate) may have an optimum at a lower resolutions than cards without AA.
HDTV = High Definition TV
DTV = Digital TV
It seems that the broadcasters are much more interested in using the digital technology to transmits six channels in the same bandwidth formerly used for one than to transmit one high definition channel.
How about a solar or wind-up version for use in places that many miles away from the nearest electric socket or battery shop?
...or only expect it to work in areas with very dense node populations (the urban WiFi solution).
This might be true if the system relied entirely on peer-to-peer routing.
Let's say that the system has enough fixed base stations to get full coverage of the operating area. The only problem is capacity - it can't support more than a certain density of terminals per square mile. The standard approach to this problem in cellular networks is to add more base stations to reduce the cell radius leading to a reduction in transmission power and a better frequency reuse factor. With this system whenever there is a high density of terminals it compensates automatically by using a number of short-range low-power hops to get to the nearest base station instead of one high-powered hop that wastes frequency capacity over a large area.
Basic truth: for reliable low-power communication, at least one end of the link needs to be well-sited.
This "basic truth" is true only assuming the link has only two ends and therefore just one communication path. If this path is degraded by fading or shadowing you must have adequate power margins to cope with it.
On an adaptive mesh network you have multiple routes through repeaters to the nearest base station. At least some of those paths should have favorable reception conditions and be capable of running at very low power.
It may seem unreliable to trust statistics but phone networks have done so for ages. If you are stuck without enough repeaters your terminal can jack up its power all the way up to normal maximum power levels of cellular phones (a few hundred milliwatts) and talk directly to the base station. But wait - this wastes frequency capacity over a larger area, right? Not a problem. If you don't have neighbors to carry your traffic it means that they don't need this capacity at this time!
Anyways, why not modify this so low-power, discrete antennas can do the job instead of other phones? Putting a small repeater every few light poles on the highway or along streets in areas of poor reception would vastly improve reception (if not coverage) and avoid the need for as many towers.
You have just described the Metricom Ricochet network (RIP).
The cap is on the *uplink*. You can still download as much pr0n as you like...
To calculate the value per bit you need to figure out the amount of information encoded by the location of that chalk mark.
That is log2(area/resolution)
Where area is the total surface area of the machines and resolution is the area representing the relevant accuracy of the chalk mark.
There is plenty of moving mass in the universe. Has anyone measured a gravitomagnetic effect?
The problem is that there is either big mass moving slowly or small mass moving fast. You need a big mass to move fast to get a measurable effect. A supernova in our galaxy should generate a gravitomagnetic field big enough to measure with current sensors. On average, they happens once every few hundred years. We just need to wait...
IIRC, the gravitomagnetic field has been measured indirectly by observing the slowdown of a rapidly rotating binary star. The rate of deceleration not accounted for by other effects matched the predicted amount of energy it was supposed to lose by radiating gravitation waves with very good accuracy.
Capitalism suffers from exactly the same problem as communism: it works great in theory, because it assumes that people are basically good and honest and will cooperate with the spirit as well as the letter of the system.
Oh, that's not the real problem. Capitalism works just fine. It's corporatism that sucks.
If the Gibralter Bridge is ever built, I predict it to be an incredible boost to the economies of both Europe and Africa. Industry in Europe could gain by getting cheap labor in Africa, while nations in Africa will receive heavy investments - Improving their infrastructure. Surely it would be a Win-Win situation for both Africa and Europe.
Perhaps if Carthago had triumphed over Rome it would have been the other way around...
I think active vibration dampening has already been demonstrated in diesel engines and it cuts down on noise and, perhaps more importantly, reduces wear.
How about an active automobile suspension that also has a millimeter wave radar looking forward to anticipate bumps and potholes?
10^90 is about 2^300 bits
10^120 is about 2^400 operations
Now, can anyone explain to me why anyone would need a cryptographic hash function with a 512 bit output?
The article talks about using the underground conduits to pass communication cables in addition to the electric wires, not about transmitting data over the power lines.
Powerline communication is nice, but it can't quite compete with fiber.