I suspect he meant monochrome, which is still an acceptable way of viewing the Mandelbrot set. Points are either in the Mandelbrot set or they are not in it.
However there is also the intrinsic difficulty of determining that any given point is not in the set, which is normally represented as variation in the point's brightness or color. (If you fail to determine that a given point is not in the set, the algorithm eventually terminates under the assumption that it is.)
The best you can do is make it appear you are further away than you really are.
That's all you need to do. Your network's latency will already make you look farther away than you really are, so the triangulation will have to ignore it.
If your average ping is 50 ms to LA and 12 ms to NYC, you're probably closer to NYC.
If you're on a connection with high latency and your ping is 500 ms to LA and 120 ms to NYC, you're still probably closer to NYC.
So if your real ping is 50 ms to LA and 12 ms to NYC, by delaying long enough before sending responses to servers in NYC it'll appear that you're closer to LA.
I'll end up looking further away than you think whatever happens.
I'm not worried about how far away you seem to appear, I'm worried about the relative distances you appear to be from points A, B, and C. Given that larger distances cause larger average delays, I can triangulate your location. It doesn't matter if there's a constant added to the delay somewhere, as long as it's always the same constant after I've averaged out enough samples.
And I'll leave alone the bit about adding a negative delay...
the average bloke is narrowed down to 1km, that's still a good 50-100 residential properties, and no way for the "attacker" to know which, so this attack on it's own doesn't do much
It'd be plenty good for showing him ads for restaurants and stores that he'd probably drive past on a regular basis, though.
So if you introduce some random delay in responding to pings
Then they just have to ping you enough times and the random delay will average out.
or don't reply to them at all
It doesn't necessarily have to be a ping. Any connection would work as long as you could time how long it took between sending the packet and getting a response. That said, putting a condom over your ethernet plug would probably protect you quite well.
By introducing delay into your reply, could you fake your position to somewhere completely different?
You'd probably have to know the locations of the servers you were being pinged from and introduce specific delays to make it look like you were farther from the ones closest to you than you were from the ones closer to where you wanted to seem to be. Theoretically possible, at least.
The amount of latency inherent in your connection wouldn't matter, so long as it was fairly consistent. As long as a route of longer distance consistently returned longer ping times than a route of shorter distance, it could be inferred that you're closer to the server which can ping you quicker.
Sure, but building a drone with a gyroscope, giving it some GPS coordinates, having it surface and take a fix on its location and dive and follow its route isn't all that hard. Finding and following an enemy sub that doesn't want to be found or followed, and doing it without the sub noticing that it's being followed, are significantly harder.
Still, the key difference between this and Perlin noise is that this is formed by using short repeating patterns whereas Perlin noise relies upon an infinite pseudo-random number generator that shouldn't ever appear to repeat itself.
The pseudo-random number generation, in this case, is in the x,y offsets of the tiles, not in the data contained in the tiles themselves - the tiles themselves are static PNGs. It's basically very similar to a simple linear congruential generator determining where the data on the tiles ends up.
So you've completely and utterly lost the argument which was directly related to music and only music
So in the process of "winning" the argument about music, you've completely and utterly lost the argument which was directly related to copyright in general and copyrightable works in general. Your argument only holds for the specific case of music, and that only in the specific case of buying it without a contract, and that only because the industry chooses to sell it like that. If you wanted a license to stream it online, include it in a for-profit work, broadcast the music, etc. you would need a signed contract authorizing you to do so.
So in the normal situation the copyright owner does not dictate the terms of use.
They dictate that you're allowed to buy it under the standard terms allowed in copyright law rather than having to sign a contract. But if they wanted to sell you a contract with other terms, they could. So it's up to them, i.e. they dictate which you can buy because they control which they sell.
Once you're getting to the point where your tiling algorithm is more complex than just "move right N places and place another copy of the tile" you might as well use the standard library you're given instead of reinventing the wheel (or the Monotonic Random Walk in this case).
If you wanted to generate your backgrounds on <canvas> elements with Javascript, sure, you could come up with something better using the built-in pseudo-random number generator. However, this is pretty good for a dumb, tiling CSS background pattern with a fairly large logical size but made up of relatively small elements.
This is very much not like Perlin noise, because Perlin noise uses octaves (doubles in frequency). Octaves are harmonic with each other by definition. This uses primes, specifically to cause the harmonics to occur as far apart as possible. Using octaves in this way would cause very repetitive-seeming patterns because the maximum size of your pattern would be defined as the size of your largest sequence, and all of the shorter sequences would tile into it in a neat checkerboard.
Perlin noise requires infinite sequences of pseudo-random numbers and would be extremely ill-suited to using short repeating sequences. This is specifically designed to minimize the length of the sequences you use without causing obvious repetitions in the pattern by using sequences of prime length (since your "sequence" is a PNG, if it's too large it takes a long time to load).
The point isn't randomness, the point is unwanted harmonics in pseudo-random patterns. These unwanted harmonics cause regular repetitions in the pattern that make it seem predictable and non-random. Prime numbers are the basis by which a simple PRNG (pseudo-random number generator) generates seemingly-random data that doesn't repeat in any predictable manner. By overlapping two or more sequences with prime lengths, the length of the harmonic is maximized. That means the sequence goes longer before repeating itself. Sequences with non-prime lengths short-circuit the cycle.
For instance, overlapping three sequences of length 7, 11, and 13 forms the following pattern: http://tinyurl.com/3wserj7
At a glance, the pattern looks fairly random and non-repeating; however if you look more closely you see that the vertical bands of color are repeating very regularly within the pattern. But, since their periodicity is prime, the pattern as a whole doesn't appear to repeat itself. Using alpha and larger 2-dimensional tiles you can create even more complex and random-seeming patterns.
The life cycle of cicadas is similar in that the overlapping cycles tend to cause a seemingly-random pattern of years with lots of cicadas and few cicadas, such that the life cycle of their predators is less likely to hit a bunch of good cicada years in a row and seriously harm the population of them.
If so, I don't think they're planning on using it much mid-mission. From the PDF on the drones (pg. 6):
Autonomy
Independently deployable unmanned system Sparse shore-based remote supervisory command and control model Capable of autonomous risk-based mission continuation through command and control interruptions
Adaptive constraint set based on strategic context, mission phase, internal state, and external conditions
Compliance with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) and maritime law
High fidelity surface navigation and situational awareness sensors
High fidelity internal state awareness and dynamic performance assessment
It seems like they're planning on launching these things and then having them operate completely autonomously - most likely it'll only communicate with its land-based handlers at the very beginning/end of its mission.
What? The USGS states that the depth was 49.0 km, and that's not even all that particularly deep. Some of the quakes listed for the past few days were much deeper.
These drones will be underwater, which means it'll be very difficult to make radio communication with them. Also you have to keep in mind that underwater tracking and evasion depends very highly upon stealth. It probably wouldn't be broadcasting anything to avoid giving away its presence.
I find that interesting because it implies that the intelligence required to navigate the sub and track enemies will probably have to be built in to the sub's on-board computer rather than having someone control a dumb drone remotely like the unmanned aerial drones. This will probably be much more autonomous.
At the end of your "mission" you're asked whether you'd like to submit your (anonymous) game to the DARPA for them to analyze your tactics and how well they worked out:
As you complete each scenario in the simulation you will be asked if you would like to submit data about your game play to our database for analysis. The data collected doesn't contain any information about you or your computer, or anything else outside of what you did with ACTUV and how well it worked. Good or bad, please agree to submit your data for analysis so that we can see what tactics work (or don't work!).
Who knows... somebody out there might come up with a strategy that nobody ever thought of before.
Posts that have been moderated once don't have a moderation adjective. It's been that way since before the site redesign, so I think it was intentional. A post with an Excellent karma bonus and one +1 mod will be rated +3 Normal.
I'm in FF4 and the link in TFS works just fine, though the links in comments don't. Double-right-clicking the link (since right-click is broken too) and selecting "open in new tab" works though.
It's probably some sort of polynomial relation - energy being converted into motion of land mass in 3D, causing both horizontal and vertical motion, and the actual damage being related in some other polynomial way to the intensity of the shaking (complex, because you get shear forces in the horizontal combined with tensile and compressive forces in the vertical, and building materials act very differently under shear/compression/tension). And of course not to mention the fact that the damage is greatly dependent on how well the stuff was engineered in the first place. How well or poorly the logarithmic scale represents that complex relationship is sort of anyone's guess.
If you can access all of the data in the user's account without their password, even through a backdoor, it's no more secure than if you just stored the password in plain text.
Seed a particular PRNG with their UID and generate a random master password (unique for every user) and use it to encrypt the user's actual password. Store that in a separate database, preferably on a separate server, from the regular users database. The regular users database just gets a hashed password. Then, an attacker would have to gain access to both databases (because the only way to connect a username to a password would be by cross-referencing the UIDs in the databases), the exact implementation of the PRNG you had used (or deduce it from analysis of the encrypted passwords), and they'd have to have the private key to decrypt them anyway. Having the users database would get them only hashes, and having the encrypted password database still wouldn't allow them to brute-force all of the passwords in one go.
Slashdot Mirror
I suspect he meant monochrome, which is still an acceptable way of viewing the Mandelbrot set. Points are either in the Mandelbrot set or they are not in it.
However there is also the intrinsic difficulty of determining that any given point is not in the set, which is normally represented as variation in the point's brightness or color. (If you fail to determine that a given point is not in the set, the algorithm eventually terminates under the assumption that it is.)
The best you can do is make it appear you are further away than you really are.
That's all you need to do. Your network's latency will already make you look farther away than you really are, so the triangulation will have to ignore it.
If your average ping is 50 ms to LA and 12 ms to NYC, you're probably closer to NYC.
If you're on a connection with high latency and your ping is 500 ms to LA and 120 ms to NYC, you're still probably closer to NYC.
So if your real ping is 50 ms to LA and 12 ms to NYC, by delaying long enough before sending responses to servers in NYC it'll appear that you're closer to LA.
I'll end up looking further away than you think whatever happens.
I'm not worried about how far away you seem to appear, I'm worried about the relative distances you appear to be from points A, B, and C. Given that larger distances cause larger average delays, I can triangulate your location. It doesn't matter if there's a constant added to the delay somewhere, as long as it's always the same constant after I've averaged out enough samples.
And I'll leave alone the bit about adding a negative delay...
the average bloke is narrowed down to 1km, that's still a good 50-100 residential properties, and no way for the "attacker" to know which, so this attack on it's own doesn't do much
It'd be plenty good for showing him ads for restaurants and stores that he'd probably drive past on a regular basis, though.
So if you introduce some random delay in responding to pings
Then they just have to ping you enough times and the random delay will average out.
or don't reply to them at all
It doesn't necessarily have to be a ping. Any connection would work as long as you could time how long it took between sending the packet and getting a response. That said, putting a condom over your ethernet plug would probably protect you quite well.
By introducing delay into your reply, could you fake your position to somewhere completely different?
You'd probably have to know the locations of the servers you were being pinged from and introduce specific delays to make it look like you were farther from the ones closest to you than you were from the ones closer to where you wanted to seem to be. Theoretically possible, at least.
The amount of latency inherent in your connection wouldn't matter, so long as it was fairly consistent. As long as a route of longer distance consistently returned longer ping times than a route of shorter distance, it could be inferred that you're closer to the server which can ping you quicker.
Sure, but building a drone with a gyroscope, giving it some GPS coordinates, having it surface and take a fix on its location and dive and follow its route isn't all that hard. Finding and following an enemy sub that doesn't want to be found or followed, and doing it without the sub noticing that it's being followed, are significantly harder.
Still, the key difference between this and Perlin noise is that this is formed by using short repeating patterns whereas Perlin noise relies upon an infinite pseudo-random number generator that shouldn't ever appear to repeat itself.
The pseudo-random number generation, in this case, is in the x,y offsets of the tiles, not in the data contained in the tiles themselves - the tiles themselves are static PNGs. It's basically very similar to a simple linear congruential generator determining where the data on the tiles ends up.
So you've completely and utterly lost the argument which was directly related to music and only music
So in the process of "winning" the argument about music, you've completely and utterly lost the argument which was directly related to copyright in general and copyrightable works in general. Your argument only holds for the specific case of music, and that only in the specific case of buying it without a contract, and that only because the industry chooses to sell it like that. If you wanted a license to stream it online, include it in a for-profit work, broadcast the music, etc. you would need a signed contract authorizing you to do so.
So in the normal situation the copyright owner does not dictate the terms of use.
They dictate that you're allowed to buy it under the standard terms allowed in copyright law rather than having to sign a contract. But if they wanted to sell you a contract with other terms, they could. So it's up to them, i.e. they dictate which you can buy because they control which they sell.
Once you're getting to the point where your tiling algorithm is more complex than just "move right N places and place another copy of the tile" you might as well use the standard library you're given instead of reinventing the wheel (or the Monotonic Random Walk in this case).
If you wanted to generate your backgrounds on <canvas> elements with Javascript, sure, you could come up with something better using the built-in pseudo-random number generator. However, this is pretty good for a dumb, tiling CSS background pattern with a fairly large logical size but made up of relatively small elements.
This is very much not like Perlin noise, because Perlin noise uses octaves (doubles in frequency). Octaves are harmonic with each other by definition. This uses primes, specifically to cause the harmonics to occur as far apart as possible. Using octaves in this way would cause very repetitive-seeming patterns because the maximum size of your pattern would be defined as the size of your largest sequence, and all of the shorter sequences would tile into it in a neat checkerboard.
Perlin noise requires infinite sequences of pseudo-random numbers and would be extremely ill-suited to using short repeating sequences. This is specifically designed to minimize the length of the sequences you use without causing obvious repetitions in the pattern by using sequences of prime length (since your "sequence" is a PNG, if it's too large it takes a long time to load).
The point isn't randomness, the point is unwanted harmonics in pseudo-random patterns. These unwanted harmonics cause regular repetitions in the pattern that make it seem predictable and non-random. Prime numbers are the basis by which a simple PRNG (pseudo-random number generator) generates seemingly-random data that doesn't repeat in any predictable manner. By overlapping two or more sequences with prime lengths, the length of the harmonic is maximized. That means the sequence goes longer before repeating itself. Sequences with non-prime lengths short-circuit the cycle.
For instance, overlapping three sequences of length 7, 11, and 13 forms the following pattern:
http://tinyurl.com/3wserj7
At a glance, the pattern looks fairly random and non-repeating; however if you look more closely you see that the vertical bands of color are repeating very regularly within the pattern. But, since their periodicity is prime, the pattern as a whole doesn't appear to repeat itself. Using alpha and larger 2-dimensional tiles you can create even more complex and random-seeming patterns.
The life cycle of cicadas is similar in that the overlapping cycles tend to cause a seemingly-random pattern of years with lots of cicadas and few cicadas, such that the life cycle of their predators is less likely to hit a bunch of good cicada years in a row and seriously harm the population of them.
If so, I don't think they're planning on using it much mid-mission. From the PDF on the drones (pg. 6):
Autonomy
Independently deployable unmanned system
Sparse shore-based remote supervisory command and control model
Capable of autonomous risk-based mission continuation through command and control interruptions
Adaptive constraint set based on strategic context, mission phase, internal state, and external conditions
Compliance with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) and maritime law
High fidelity surface navigation and situational awareness sensors
High fidelity internal state awareness and dynamic performance assessment
It seems like they're planning on launching these things and then having them operate completely autonomously - most likely it'll only communicate with its land-based handlers at the very beginning/end of its mission.
What? The USGS states that the depth was 49.0 km, and that's not even all that particularly deep. Some of the quakes listed for the past few days were much deeper.
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/quakes_all.php
I always thought it was a game of Simon...
These drones will be underwater, which means it'll be very difficult to make radio communication with them. Also you have to keep in mind that underwater tracking and evasion depends very highly upon stealth. It probably wouldn't be broadcasting anything to avoid giving away its presence.
I find that interesting because it implies that the intelligence required to navigate the sub and track enemies will probably have to be built in to the sub's on-board computer rather than having someone control a dumb drone remotely like the unmanned aerial drones. This will probably be much more autonomous.
At the end of your "mission" you're asked whether you'd like to submit your (anonymous) game to the DARPA for them to analyze your tactics and how well they worked out:
As you complete each scenario in the simulation you will be asked if you would like to submit data about your game play to our database for analysis. The data collected doesn't contain any information about you or your computer, or anything else outside of what you did with ACTUV and how well it worked. Good or bad, please agree to submit your data for analysis so that we can see what tactics work (or don't work!).
Who knows... somebody out there might come up with a strategy that nobody ever thought of before.
Posts that have been moderated once don't have a moderation adjective. It's been that way since before the site redesign, so I think it was intentional. A post with an Excellent karma bonus and one +1 mod will be rated +3 Normal.
I'm in FF4 and the link in TFS works just fine, though the links in comments don't. Double-right-clicking the link (since right-click is broken too) and selecting "open in new tab" works though.
Also, the checkbox to post anonymously doesn't work any more.
Same issue here. This bookmarklet works around it:
javascript:for(var a=document.getElementsByTagName('input'),i=0;i<a.length;i++)if(a[i].id.indexOf('postanon_')==0)a[i].checked=true;void(0);
It'll take a while for the scientists to agree on what it was. In the meantime, changing anything would be premature.
Here. Happy now?
http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0002ksa.php
It's probably some sort of polynomial relation - energy being converted into motion of land mass in 3D, causing both horizontal and vertical motion, and the actual damage being related in some other polynomial way to the intensity of the shaking (complex, because you get shear forces in the horizontal combined with tensile and compressive forces in the vertical, and building materials act very differently under shear/compression/tension). And of course not to mention the fact that the damage is greatly dependent on how well the stuff was engineered in the first place. How well or poorly the logarithmic scale represents that complex relationship is sort of anyone's guess.
If you can access all of the data in the user's account without their password, even through a backdoor, it's no more secure than if you just stored the password in plain text.
How about this:
Seed a particular PRNG with their UID and generate a random master password (unique for every user) and use it to encrypt the user's actual password. Store that in a separate database, preferably on a separate server, from the regular users database. The regular users database just gets a hashed password. Then, an attacker would have to gain access to both databases (because the only way to connect a username to a password would be by cross-referencing the UIDs in the databases), the exact implementation of the PRNG you had used (or deduce it from analysis of the encrypted passwords), and they'd have to have the private key to decrypt them anyway. Having the users database would get them only hashes, and having the encrypted password database still wouldn't allow them to brute-force all of the passwords in one go.