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A New Algorithm Could Protect Ships From 'Rogue Waves' (cio.com)
itwbennett writes: MIT researchers have developed a tool they say can predict so-called rogue waves, giant waves that seem to appear out of nowhere and can cause devastation to ships unlucky enough to be struck by them. The researchers found that certain wave groups end up 'focusing' or exchanging energy in a way that eventually leads to a rogue wave. The tool they developed uses an algorithm that sifts through data from surrounding waves and computes a probability that a particular wave group will turn into a rogue wave within the next few minutes.
Would this make ocean-going ground-effect aircraft (a la Ekranoplans) viable? It could create a third tier of shipping in between ship and air. Assuming, of course, that the necessary data can be gathered while traveling across the waves at several hundred mph.
i wish there was technology to protect against rogue youtube links that are dumb and posted by dumb people who complained about getting their dumb link out twice when if they had done it 0 times it would be less dumb.
morons.
Beware of well wishers that do not know anyone on the boat as it leaves.
This causes great confusion. Legitimate wavers are overlooked as passengers divert their gaze to the rogue and miss a last chance farewell.
The "next few minutes" is basically just enough time to give the "abandon ship" order. To be useful the algorithm has to predict the rogue wave far enough in advance to let the ship turn and steam clear of the wave group. In a storm, that's probably 20-30 minutes which I don't see happening any time soon.
This is the part that I don't get: How is this algorithm supposed to "Protect" the ship. Sounds like only thing it can do is predict that one will be forming.
If so, how can a ship possibly survive such a gigantic wave even if it knows it is coming? Would this algorithm even predict what direction it is coming from? I recall that I heard somewhere that a best way to cross a wave is to go at it on a 45 degree angle. Not sure where I read that...
Surely we have slashdoters that have great knowledge of seafaring. What would be the best course that a ship can take to survive such a sudden mountain of water?
Wreck? Rude?
Wreak. Ride.
Aside from your atrocious spelling, your facts are false and misleading. Not all ships are large enough to withstand 10 meter waves. No ship can "deal with any storm the ocean can throw at it". The size of the wave makes a big difference, regardless of slope. If a large wave crests and comes down on you you're fucked. It a large wave hits you at a bad angle, you're fucked.
When waves interact they generate an interference pattern. The interference pattern will have larger up and downs than the original waves. However, it might not be obvious to a ship that they are in such an interference pattern, as locally the sea looks like waves. Depending on the path of the boat, shortly before the peak of the interference pattern, you may see an unusually quiet region. I could see how it would get a mariner confused.
What I never understood was if rogue waves were caused by interference patterns, or something completely different like under-ocean mudslides. If this research works out, maybe we will know the answer.
Ok, so i like the research, but the theory that it could be used anytime soon for some type of rouge wave detection or prevention seems far fetched. I don't see it being very easy to map out wave activity in a large enough area in all the varying conditions you come across at sea AND produce any useful lead time in warning no less what does a warning do. Boats maneuver like.. boats. When you're out in the vast fluid dynamics of the ocean there isn't much you're going to do to get away from a wave or block the force of it's impact. Perhaps we can come up with areas and conditions where rouge waves can be said to be more common, but real time prediction or prevention isn't happening anytime soon and why would it, rouge waves are not any kind of pressing issue. Boats are just not made to survive large waves due to their large broadsides. If you want to make a boat that is protected from a rouge wave then engineer more stable boats. What else will you do tether a giant mesh of sensor to the boat? Sounds like people getting paid for science that will never see the light of day.
Drone measures "rogue wave" -> Generates radio wave -> warns ship.
Because they built this beastie
https://en.wikipedia.org/wiki/...
I know everyone has seen the example where two waves meet up and their amplitudes add up, creating a huge peak. While the arithmetic of that is correct, the actual dynamic behavior of waves is a lot more complex. What you see as a wave is only a partial instantaneous manifestation of an energy pulse in the water. Waves do not propagate in isolation like you learned in high school. As with coupled pendulums, there is energy transference between individual waves.
So instead of taking the arithmetic approach - measuring every wave, and trying to predict when a rogue wave will happen - they're measuring wave train profiles and analyzing how they'll combine and interact. The calculations are a lot more complex, but you need a lot fewer measurements and calculations.
It appears that this is a new algorithm, that's the terminology. Regardless of any audio history, the algorithm wasn't known prior. It is now known. Thus, we call it new.
In my humble opinion, it's not new. It has always been there. It has just been uncovered, discovered, inferred, revealed, or whatever. The algorithm doesn't care if we know about it or not. It just exists. However, that's a rather long-winded way to express it and will likely confuse the folks on the short bus. So, "new" is gonna have to do unless you want really long-winded/verbose press-releases.
"So long and thanks for all the fish."
The captain will want to know about this
https://www.youtube.com/watch?...
Go well
Side of a ship: long and vertical.
Bow (that's the front): Narrow and pointy.
It makes a difference where you get hit. Have you ever even seen a boat, let alone been in one?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
This is the part that I don't get: How is this algorithm supposed to "Protect" the ship. Sounds like only thing it can do is predict that one will be forming.
If so, how can a ship possibly survive such a gigantic wave even if it knows it is coming?
There are several candidates for rogue wave generation. In most of them (such as multi-wave focus and in-phase combination of several wave components of different frequencies) the rogue wave is very limited, especially in duration. (A possible exception is a non-linear long-duration soliton, such as the sech() envelope solution for water waves.)
In particular (at least while the amplitude is low enough that the waves' behavior is approximately linear), even if all the wave energy is going in the same direction, each sinusoidial component of the wave propagates at a different speed, proportional to the square root of its length. If they add up to something like an impulse at one point, a bit farther along their travel (and also a bit farther back in it) they aren't in phase any more. The nasty spike is gone. Things quickly get back to the sort of behavior you usually see.
If you know long enough in advance (maybe a minute or two) that one of these is going to exist in its full glory where and when you will be on your current course and speed, you can just alter them: Rudder hard over and cut the engine (or let out the sail), for starters. Be in a different place where/when the wave will not have formed, will have dissipated, or will at least be lower and more diffuse - and pointed in a direction to handle what you do encounter.
Would this algorithm even predict what direction it is coming from?
Almost certainly - if it involves processing data from more than one spatially-separated sensor, or even a single sensor on a moving platform.
Surely we have slashdoters that have great knowledge of seafaring.
Or some knowledge of both seafaring and surface wave mechanics.
What would be the best course that a ship can take to survive such a sudden mountain of water?
Be somewhere else. B-)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Take a look at the graph for time-domain signals in OFDM and rogue wave plots. They look almost identical.
That's because OFDM approaches the full use of the available bandwidth for information transport. The closer you get to that, the more your signal looks like random noise.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Water waves don't have solitons
Sure they do. The second figure in the Wikipedia article on solitons is a water-wave soliton: a sine wave with a sech() envelope.
That's just a solution with mild nonlinearity. As the waves become more extreme there is more nonlinearity, and thus more opportunity for such
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I just got a new car, it was used. "New" is quite flexible.
I suppose that, by some definition, you discovered it too.
"So long and thanks for all the fish."