I built one of the compass belts. You don't need 13 motors. Four is plenty. Of course, you want finer resolution than just the four cardinal directions -- so you have the intensity of the vibration vary. If you make the strength of vibration of the motor vary sinusoidally with the angle, so that when a particular motor is pointing directly north it vibrates at full strength, and when directly south not at all, you'll get a very smooth response. You can easily resolve direction to 10-15 degrees precision with just four motors, and the analog response is less distracting than having motors suddenly turn on and off.
You can also do the analog response without a microprocessor -- the two-axis electronic compass sensors are really two sensors, each sensing the component of the field along their sensitive axis, which gives precisely the sin(theta) response curve you want. The microprocessor gets replaced by a couple op amps, and you cut the motor count dramatically, which saves a fair bit on the cost.
Power required to run the vibrator motors is noticeable. I get about 12-14 hours battery life from 4x NiMH AA cells. The next version will improve that a bit (PWM control instead of linear for the motors); the prototype was designed with circuit simplicity as the primary goal.
I don't have a complete schematic or parts list online; circuit design was done on paper and in my head while soldering it together. You can find a description and pictures here.
You're absolutely correct. You'll note that the courts basically agreed with you, with one caveat. The ruling suggested that she could potentially bring a new suit, on the basis that Yahoo specifically agreed to take down the page and then failed to do so. They didn't have any such obligation until they made that agreement. This actually seems entirely reasonable to me.
Exactly. The issue isn't that the problem is hard to solve, it's that the relevant parties don't want to bother solving it.
The basic idea behind DMCA takedown notices could work (though you'd have to solve the problems that currently has). A statement under penalty of perjury that the page is impersonating would be sufficient to take it down, and a statement by the poster that it wasn't would restore it, and then the courts could sort it out. At a start, though, you would have to find a way to have penalties for abuse have some teeth, unlike the current DMCA situation. Unfortunately, I don't know how to solve that problem well in either case...
The fact that CO2 causes warming does not mean that it is the only cause of warming. Sometimes large models with many variables require more effort than a quick glance at a couple graphs to understand, let alone "prove" or "refute".
If you have a noisy sensor and are trying to keep a low-noise estimate of the input, while that input is changing, you do some sort of filtering on the data. The weighted rolling average described above is nice for a number of reasons, mainly it's simple to implement and simple to analyze. In some cases, other filters are better.
If you have a noisy sensor and want to measure a single unchanging input, you would want a different sort of filter. In this case, the simple arithmetic average works quite well.
As you correctly observe, the two filters of similar complexity. Which one you use should depend on the sort of input you're trying to measure. In this case, they used the former type of filter on the latter type of data, which is a definite no-no. This will result in data that is far noisier than you would otherwise expect from the raw sensor noise and the number of samples taken. When that noise could be the difference between a DUI conviction and and the cop telling you to drive home carefully, I'd say that's worth worrying about.
Your method is really just a somewhat inefficient way of finding eigenvectors. Eigenvectors make a lot of sense to use there, but you can be more efficient about the details of finding them. Looked at from that angle, it also becomes clear why your solution didn't always converge (and, in fact, why it *couldn't* always converge).
I'm all in favor of harm reduction and legalization. But if you want to argue that, you should argue based on evidence. Craigslist claims their ads are associated with lower crime rates than more conventional means -- so, if you want to help the people in question, you should let them advertise on CL. Deciding to ban something because we don't like some of the effects, without concern for whether banning it is a step in the right direction or the wrong one on the whole, is exactly what caused this mess in the first place.
I'd actually like to be able to tune it. When I first search something, I'd like to see a variety of things. Frequently there are things in the search that are relevant to the search terms, but not the context I was thinking of. I'd like to be able to say "repeat the search, but I want to see more items like this one and fewer like that one." Frequently I find myself redoing the search manually, trying to think up terms to add or prohibit to get a better list. Somehow I suspect that if I just picked one or two results that were on the right track, and one or two that were totally off base, Google could do a better job refining the search from that than I could be adding more terms.
Of course, I also want the option to back up and start a clean search.
There are plenty of examples where bomb squads attempt to determine whether something is a bomb before blowing it up in situ. If you have reason to believe they would do otherwise when valuable property (like a car) is involved, cite some evidence.
Even Boston doesn't blow up everything they might be a bomb. The job of the bomb squad is not to blow up suspected bombs, it's to investigate and handle the situation appropriately. Sometimes that involves blowing something up, sometimes it doesn't.
And their design was apparently conservative: you could build it, starting TODAY.
No one has demonstrated sustained useful greater than unity energy yields from fusion outside of bombs and stars. It is entirely possible that their design would work, but the track record of fusion attempts says its unlikely. Now don't get me wrong, I'm all in favor of fusion research, and I think it's worth spending money on. But, when the fundamental concept your engineering project relies upon has not been demonstrated in a manner that obviously scales to your project, calling it conservative is a stretch. In fact, calling it engineering is a stretch -- it's scientific research. Once they have a scale model and *strong* reason to believe it will scale properly, then you can call it a viable design -- but until it or something like it has been demonstrated at scale, you can't call it conservative.
They did take those things into account. That's why the study is interesting. It includes the conversion efficiencies of both the combustion engine and the power plant, the transmission losses of both the fuel and electricity (trucking the fuel around doesn't cost much fuel, but it's not zero either), and the lifecycle energy cost of the batteries. I'm not expert enough to say the authors did a completely correct job, but they certainly did a very thorough job.
Well, if you want to get all units-nazi about it, it's the annual output of an acre. So 15000 miles per acre per year (for the bio-electric option), or 321.7 microhertz per smoot.
requiring the two parties to a lawsuit to agree on *anything* is doomed to failure.
In a trial by jury, both sides must accept a juror in order for them to be on the jury.
(cue jokes about jury failure or something)
First, jurors are quite explicitly not the same as expert witnesses in law. And second, there are very well-defined limits imposed -- it's not as simple as they both have to agree. Usually, either side can reject a juror if there is some cause for the rejection that they can get the other side or the judge to agree to, and each side has a very limited number of peremptory challenges that do not require a cause.
I was of the impression that it was fairly common to let the party doing the discovery select their own expert examiner. If the defense believe the examiner is for some reason inappropriate, for example overly biased or unqualified, they can object -- but requiring the two parties to a lawsuit to agree on *anything* is doomed to failure.
I'd probably be willing to pay that subscription rate for a few online sources. However, the hurdle isn't the price, it's the cost of performing the transaction. I have to get out my credit card, give them my info, keep track of yet another login / password pair (less annoying, but still not completely nuisance-free, if I use a password manager), and then worry about forgetting to cancel it if I stop caring, and worry about them getting hacked and my payment info stolen...
In other words, all the problems of micropayments. They have more to do with the transaction than the price. Perhaps someone will solve them soon, but I wouldn't count on it.
He's got some good points. He does express them in a way that's unnecessarily offensive and combative. But that doesn't make him an asshole. That makes him a typical geek!
Then we need fewer typical geeks, and more atypical geeks.
Indeed. For the record, I don't think he is a typical geek. But if that's your definition of typical geek, then the typical geek is an asshole.
The Tesla turbine is a really interesting idea. It may be inefficient for most applications, but in others it is the only design in serious use -- pumping live fish, for example.
Your units have some nontrivial problems with them, and your results are off by orders of magnitude. Global fossil fuel consumption is approximately 5E20 J (= 1.4E17 Watt hours), for an average rate of 1.6E13 W. Solar energy at the Earth's surface is closer to 1000W/m^2 than 1300. At 20% efficiency and 20% output factor (it isn't always noon, and it's cloudy sometimes, so you don't get 1kW average output from 1kW worth of panels; both of these numbers are optimistic, but not grossly so), that's 4E11 m^2 of panels. That's rather expensive, but then so is our current energy infrastructure.
Slashdot Mirror
I built one of the compass belts. You don't need 13 motors. Four is plenty. Of course, you want finer resolution than just the four cardinal directions -- so you have the intensity of the vibration vary. If you make the strength of vibration of the motor vary sinusoidally with the angle, so that when a particular motor is pointing directly north it vibrates at full strength, and when directly south not at all, you'll get a very smooth response. You can easily resolve direction to 10-15 degrees precision with just four motors, and the analog response is less distracting than having motors suddenly turn on and off.
You can also do the analog response without a microprocessor -- the two-axis electronic compass sensors are really two sensors, each sensing the component of the field along their sensitive axis, which gives precisely the sin(theta) response curve you want. The microprocessor gets replaced by a couple op amps, and you cut the motor count dramatically, which saves a fair bit on the cost.
Power required to run the vibrator motors is noticeable. I get about 12-14 hours battery life from 4x NiMH AA cells. The next version will improve that a bit (PWM control instead of linear for the motors); the prototype was designed with circuit simplicity as the primary goal.
I don't have a complete schematic or parts list online; circuit design was done on paper and in my head while soldering it together. You can find a description and pictures here.
You're absolutely correct. You'll note that the courts basically agreed with you, with one caveat. The ruling suggested that she could potentially bring a new suit, on the basis that Yahoo specifically agreed to take down the page and then failed to do so. They didn't have any such obligation until they made that agreement. This actually seems entirely reasonable to me.
Exactly. The issue isn't that the problem is hard to solve, it's that the relevant parties don't want to bother solving it.
The basic idea behind DMCA takedown notices could work (though you'd have to solve the problems that currently has). A statement under penalty of perjury that the page is impersonating would be sufficient to take it down, and a statement by the poster that it wasn't would restore it, and then the courts could sort it out. At a start, though, you would have to find a way to have penalties for abuse have some teeth, unlike the current DMCA situation. Unfortunately, I don't know how to solve that problem well in either case...
Actually, yes it does. At least according to (their interpretation of) the fMRI. RTFA and all that.
That, or Freenet.
The fact that CO2 causes warming does not mean that it is the only cause of warming. Sometimes large models with many variables require more effort than a quick glance at a couple graphs to understand, let alone "prove" or "refute".
What clued you in? Was it the "Posted by kdawson" line, or did it take longer than that to figure out.
Kdawson is a poor editor, even by /. standards. /. would be much improved by his absence.
If you have a noisy sensor and are trying to keep a low-noise estimate of the input, while that input is changing, you do some sort of filtering on the data. The weighted rolling average described above is nice for a number of reasons, mainly it's simple to implement and simple to analyze. In some cases, other filters are better.
If you have a noisy sensor and want to measure a single unchanging input, you would want a different sort of filter. In this case, the simple arithmetic average works quite well.
As you correctly observe, the two filters of similar complexity. Which one you use should depend on the sort of input you're trying to measure. In this case, they used the former type of filter on the latter type of data, which is a definite no-no. This will result in data that is far noisier than you would otherwise expect from the raw sensor noise and the number of samples taken. When that noise could be the difference between a DUI conviction and and the cop telling you to drive home carefully, I'd say that's worth worrying about.
Your method is really just a somewhat inefficient way of finding eigenvectors. Eigenvectors make a lot of sense to use there, but you can be more efficient about the details of finding them. Looked at from that angle, it also becomes clear why your solution didn't always converge (and, in fact, why it *couldn't* always converge).
I'm all in favor of harm reduction and legalization. But if you want to argue that, you should argue based on evidence. Craigslist claims their ads are associated with lower crime rates than more conventional means -- so, if you want to help the people in question, you should let them advertise on CL. Deciding to ban something because we don't like some of the effects, without concern for whether banning it is a step in the right direction or the wrong one on the whole, is exactly what caused this mess in the first place.
I'd actually like to be able to tune it. When I first search something, I'd like to see a variety of things. Frequently there are things in the search that are relevant to the search terms, but not the context I was thinking of. I'd like to be able to say "repeat the search, but I want to see more items like this one and fewer like that one." Frequently I find myself redoing the search manually, trying to think up terms to add or prohibit to get a better list. Somehow I suspect that if I just picked one or two results that were on the right track, and one or two that were totally off base, Google could do a better job refining the search from that than I could be adding more terms.
Of course, I also want the option to back up and start a clean search.
There are plenty of examples where bomb squads attempt to determine whether something is a bomb before blowing it up in situ. If you have reason to believe they would do otherwise when valuable property (like a car) is involved, cite some evidence.
Even Boston doesn't blow up everything they might be a bomb. The job of the bomb squad is not to blow up suspected bombs, it's to investigate and handle the situation appropriately. Sometimes that involves blowing something up, sometimes it doesn't.
I hadn't even particularly thought about that... I was just linking to the units converter as a reference.
And their design was apparently conservative: you could build it, starting TODAY.
No one has demonstrated sustained useful greater than unity energy yields from fusion outside of bombs and stars. It is entirely possible that their design would work, but the track record of fusion attempts says its unlikely. Now don't get me wrong, I'm all in favor of fusion research, and I think it's worth spending money on. But, when the fundamental concept your engineering project relies upon has not been demonstrated in a manner that obviously scales to your project, calling it conservative is a stretch. In fact, calling it engineering is a stretch -- it's scientific research. Once they have a scale model and *strong* reason to believe it will scale properly, then you can call it a viable design -- but until it or something like it has been demonstrated at scale, you can't call it conservative.
They did take those things into account. That's why the study is interesting. It includes the conversion efficiencies of both the combustion engine and the power plant, the transmission losses of both the fuel and electricity (trucking the fuel around doesn't cost much fuel, but it's not zero either), and the lifecycle energy cost of the batteries. I'm not expert enough to say the authors did a completely correct job, but they certainly did a very thorough job.
They also compare cellulosic ethanol and other non-corn options. Ars Technica has a better writeup.
Well, if you want to get all units-nazi about it, it's the annual output of an acre. So 15000 miles per acre per year (for the bio-electric option), or 321.7 microhertz per smoot.
requiring the two parties to a lawsuit to agree on *anything* is doomed to failure.
In a trial by jury, both sides must accept a juror in order for them to be on the jury. (cue jokes about jury failure or something)
First, jurors are quite explicitly not the same as expert witnesses in law. And second, there are very well-defined limits imposed -- it's not as simple as they both have to agree. Usually, either side can reject a juror if there is some cause for the rejection that they can get the other side or the judge to agree to, and each side has a very limited number of peremptory challenges that do not require a cause.
I was of the impression that it was fairly common to let the party doing the discovery select their own expert examiner. If the defense believe the examiner is for some reason inappropriate, for example overly biased or unqualified, they can object -- but requiring the two parties to a lawsuit to agree on *anything* is doomed to failure.
This actually seems quite sane to me.
(IANAL, of course.)
I'd probably be willing to pay that subscription rate for a few online sources. However, the hurdle isn't the price, it's the cost of performing the transaction. I have to get out my credit card, give them my info, keep track of yet another login / password pair (less annoying, but still not completely nuisance-free, if I use a password manager), and then worry about forgetting to cancel it if I stop caring, and worry about them getting hacked and my payment info stolen...
In other words, all the problems of micropayments. They have more to do with the transaction than the price. Perhaps someone will solve them soon, but I wouldn't count on it.
He's got some good points. He does express them in a way that's unnecessarily offensive and combative. But that doesn't make him an asshole. That makes him a typical geek!
Then we need fewer typical geeks, and more atypical geeks.
Indeed. For the record, I don't think he is a typical geek. But if that's your definition of typical geek, then the typical geek is an asshole.
The Tesla turbine is a really interesting idea. It may be inefficient for most applications, but in others it is the only design in serious use -- pumping live fish, for example.
Also, kdawson != editor.
But I suppose we already knew that.
Solar energy is rather offtopic, but...
Your units have some nontrivial problems with them, and your results are off by orders of magnitude. Global fossil fuel consumption is approximately 5E20 J (= 1.4E17 Watt hours), for an average rate of 1.6E13 W. Solar energy at the Earth's surface is closer to 1000W/m^2 than 1300. At 20% efficiency and 20% output factor (it isn't always noon, and it's cloudy sometimes, so you don't get 1kW average output from 1kW worth of panels; both of these numbers are optimistic, but not grossly so), that's 4E11 m^2 of panels. That's rather expensive, but then so is our current energy infrastructure.