Kenton headed up the open source rewrite, not the original version. The original authors were aware of ASN.1. PBs have backward *and* forward compatibility, a compact wire-format, and try very hard to stay simple. Most other encodings achieve only two out of the three.
Of course, this is probably missing the point. Unless you're doing intensive numerical work, you probably don't need the performance.
...or if you are a company with a large web presence. Using something that runs at half the speed of C++ is not a big deal if you only have 2 servers. However, if you have 1000, then its wasting a lot of money, and it's worth the extra programming time to tune the system. This is kind of why I like OCaml (though I don't get to use it at work), it's a very good balance of a mostly-functional language, speed, and pragmatic features.
A system such as Hawkeye CANNOT BE MORE ACCURATE than humans. From the link in the article, the Hawkeye system uses 5 cameras to compute the 3D position of the ball. That's an overdetermined system of equations, which cannot have a unique solution due to observation errors in the camera views.
Luckily there's a 100+ year old discipline called statistics, and 60+ years of literature on tracking to help you out in these cases.
So Hawkeye has to complement the equations with an ARBITRARY rule, eg least squares and this arbitrariness makes the Hawkeye estimate neither more accurate nor less accurate than humans, just different. FYI, there are plenty of other arbitrary rules that work, eg least absolute errors, maximum entropy, etc.
While I can't speak for the designers of the Hawkeye, in tracking there are very good reasons to choose one form of error minimization versus another. It only seems arbitrary because you are not informed on the subject, but there's plenty of free papers out there to read and discover.
To explain current methods, please start out with this paper, in particular Figure 2, you'll see that the sort of errors you get from a camera are indeed well fit by a Gaussian. While a camera's perspective transformation is not purely linear (and various forms of distortion make it also non-linear), a good camera with a decent lens estimating the ball location within a limited area is well approximated by a linear model (and you can characterize just how much the error is). Now, a bunch of cameras with a Gaussian error distribution in the image plane with a linear projection out into the world is still a Gaussian (with a transformed covariance matrix). You can then multiply the independent measurements from multiple cameras to get a better estimate. Add a time series to that and apply this recursively and you get a Kalman filter, something invented for aerial tracking and still in widespread use today. If something is good enough for missiles to intercept other missiles, it ought to be good enough for a tennis match.
If the linear approximation not good enough for you, you can use a Rao-Blackwellized Kalman filter. If that's still not good enough because you want to use another error distribution or non-linearizable dynamics, set up a particle filter with a whole lot of particles and enough CPU to simulate it. The point is that what you call arbitrary is a well studied field which is many decades old. You'd be best served by learning about it first before you cast away all that work. I'm not a "tracking" person, just a user of there work. When a field of science has done its job well enough that it has become common engineering, and you can go look up whatever you need in books, with all the derivations, caveats and tradeoffs laid out there for you to see, I would say that that field has done a pretty good job.
The whole media story around this paper is ridiculous. It's a paper from a social sciences department about how the public does not understand the fallibility of these machines due to noise. That's all this paper is about: Hawkeye has error. I hate to break it to the uninformed, but all measurement systems have error. From Galileo to Gravity Probe B, your results can only be as accurate as your measurements, calculations, and statistical models will allow. You can decrease error with various methods, but you can never completely eliminate it. People should not be able to get out of high school without understanding accuracy on measurements, and some rudimentary statistics, but unfortunately our education system hasn't been able to reach that goal. As a result, the public doesn't understand error, and might come to believ
Sure, but it'd make an awesome cautionary tale for other civilizations: Humans, on the brink of disaster due to peak oil, created an organism to solve their engery needs. Unfortunately, it got into the wild, and ended up consuming everything and drowning all surface life in oil.
No they can't. That's the point. If you can't understand that a 1kt weapon isn't sufficient to level a city then how can I go about convincing you that you hold an irrational belief? Ah, the "You didn't level New York, just lower Manhattan" technicality. If you want to be strict about it, a nuke can't level any city, since there will still be the occasional bank safe that survives. 1kt is sufficient for the downtown section of many cities. Though you are correct in that it will not completely level one, I don't think that was the original the point.
If you want to level a city, you need at least 10s of kilotons and you need to detonate it at an altitude of about 2,000ft. Just because one cannot think of something doesn't mean others with sufficient creativity cannot. The height problem is solved easily by going to the top of the tallest building you can find, which will get you 1000-1400ft of elevation in major cities. Need a bigger bomb? Deliver it in a coke machine (idea borrowed from a movie of course).
A guy with a backpack bomb on, would likely only be able to carry about a 0.1kt bomb and detonating it at ground level would cause less damage than the Oklahoma City bombing.. and for that kind of bang there's cheaper ways to spend your bucks. ...ignoring the 1kt bomb already linked to in Wikipedia. 70kg can be carried, you would just need to make yourself look like a backpacker. A 200kt weapon would fit in a coke machine, office furniture, small industrial equipment, etc. Also, for reference, the Oklahoma City truck bomb had a yield of only 0.002kt (i.e. 2 tons). So, even by your estimation of 0.1kt for a portable nuke, you would expect a 50x more powerful weapon detonated at the same elevation to have a lesser effect? Granted, the Oklahoma bomber got "lucky" in finding a weak spot, but a more portable weapon could be placed almost anywhere to get maximum effect.
The whole "OMG Backpack Nuke!" hysteria is just a reflection of how poorly the average person understands anything with the word "nuclear" in it and immediately fears it. You should know better. You seem to be mixing practicality and likelihood with possibility. Just because something is unlikely to ever be a real threat doesn't make it impossible. As a physics and design problem, it's already been solved. We're just (thankfully) unlikely to ever see the effects due to engineering difficulty.
sorry buddy, QuantumG is correct. There's this thing called critical mass, see.. and the geometry has to maximize contact between the various (very, ridiculously expensive, even by national standards) globs of enriched uranium. Uranium hasn't been the material of choice since the 1940s. If you use plutonium, you would only need a 10kg, 10cm diameter sphere. With modern high explosive detonation you will need even slightly less, since the shockwave compression is what makes the fissile mass go supercritical.
It's probably possible to make one that can fit in a small car easily, but not possible to make a suitcase/backpack nuke. And certainly not one the size of a soccer ball. How about an elongated soccer ball?
That said, there's a lot of things I fear way more than a backpack nuke as modern-city-life-ending threats, such as ebola[1]. Even those "more likely" threats are remote, and the nuke attack is more movie plot than reality. However, it is not correct to say a man-portable nuke is not possible, when they have already existed for some time. Do you also not believe in weaponized smallpox?
[1] Ebola in different forms has been airborne (Virginia outbreak between monkeys) or highly fatal to humans (most other outbreaks). It's only a matter of time before a strain manages both.
"Valve Unveils Steam Cloud"... come on... that should have been "Valve Releases Steam Cloud"... Yes but at the moment this new version of Steam is just vaporware. Thus I'll leave mine on the back burner until new Steam is produced.
What are the chances of puttering around for a few hundred meters on earth and randomly finding a human skeleton?.. Pretty good if you touch down at a well chosen landing site. You just need to find the Martian equivalent of the Manson ranch, or an empty lot with disturbed soil near the Martian Mafia. Given the planet's drying history, there would have been a lot of drifters, and similarly criminals to prey upon them.
Some people say I've been reading to much Heinlein lately...
A completely minor comment, but I'm struck by that strange and vaguely illiterate use of "precisely." I mean, could the spacecraft not touch down at some "precise" instant? Isn't it the nature of momentary events like touchdown to, well, happen in one precise moment? Well, both prior Mars missions using airbags did not touch down at a precise moment, having bounced, tumbled, and rolled for a significant period of time. So maybe this is a a deep reference to the use of rockets+legs for landing, and the fact that they really stuck the landing.
Then again maybe not, but if you're going to read too much into TFS, the best I can do is return the favor. Have a nice day:)
If it can be measured, we can figure out how to make it fair. And I'd like to add: If we can't measure it, we don't have a valid basis to call it unfair. So, lets get on with the science and leave this tired ethical debate.
I'm sorry if this is too hard for you to understand, but it's a *shade* more complicated. He has BOTH a considerable handicap AND an unfair advantage. And after all, doesn't the poor dear deserve the benefit of the doubt?
Woolly-minded emotional people think they "probably more or less" cancel out. Scientific minded people think we should measure it and see if it cancels out, to the best of our current scientific ability.
Those with the ability to think clearly can see that, if one disabled person is allowed to compete using artificial aids, an arbitrary number of others will in future. Among them, there may well be some world-class athletes who, with prosthetics, will easily beat all "normally abled" athletes. Only if those people have the ability to think but not to calculate. If it can be measured, we can figure out how to make it fair.
I've seen a lot people making that suggestion in the various discussions of this issue. It's very disingenuous, because even for the most fanatical competitor there is a lot more to life than sport. Nobody would make such an extreme sacrifice (voluntarily, at least) just to win a gold medal or set a world record. Olympians are not normal people. They are people who really will sacrifice their entire childhood and early adulthood to a single-minded pursuit of a sport, everything else be damned (at least for the most competitive sports). Read books about their lives, or watch some documentaries; The same sort of story repeats, and its both astoundingly brave and tragic at the same time.
In light of that, there are a reasonable fraction of athletes who would willingly sacrifice their future too. Most performance enhancing drugs have very serious negative consequences down the road, and yet you see athletes at almost every level now who willingly make that trade whenever they think they can get away with it. There was an anonymous study once of Olympic hopefuls which asked if they would take a drug if they knew it would guarantee a gold medal, was undetectable, but would kill them in ten years. I can no longer find the reference, but almost unbelievably, a nontrivial fraction of the athletes said they would take the drug.
I suspect that people who argue this way don't take the Olympics very seriously. After all, it's just a lot of people playing silly games, isn't it? Besides, many of us nowadays disapprove morally of competition, because most of the competitors must lose. It's often urged how unfair this is, which is why school events are often arranged so that everyone gets prizes. After all, aren't we all very special? No, I just think its fine to adjust things until they are deemed fair. A athlete cancer patient can get all the help they need to get them back to normal, and that's fair as far as I'm concerned. Athletes routinely get exceptions for drugs to treat serious medical conditions, even using drugs that would otherwise be banned. A lot of thought goes into the allowances for exceptions, and they are difficult to get. However its a defined process, and I think the same thing should apply here (and from the looks of it, that's happening).
The only downside is that it pretty much destroys the integrity of the Olympic Games. In any competition, loss of integrity is the norm, and the controlling body must constantly struggle to keep it. It's not something to be lost, it is something already lost that we must try to gain and keep with constant maintenance. Looking at exceptional cases on top of the already large burden isn't really that much additional work.
All of which are available to every competitor. This guy's prosthetic legs are performance enhancing technology that is not available or usable by any other competitor. Sure they are, and athlete can just amputate his feet and he can use them too. Yet no athlete seems to want to do this -- even in a sport where the competitors will take drugs they know could cause serious medical complications if they think they can get away with it. If it was such an advantage, people would already be doing it. They aren't.
Technology that provides an unfair or unsafe advantage can be accounted for in the rules but those rules have to be applied uniformly. Ok, then please cite the research showing undeniably that a runner with missing feet and these particular blades is better than a normal runner. Stop simply assuming it's the case.
Performance enhancing drugs have been ruled illegal primarily for safety reasons but also because it becomes a technological arms race defeating the whole point of fair competition. I cannot find a logical distinction between performance enhancing drugs and performance enhancing prosthetics. Yet, athletes are allowed to take drugs for medical conditions. That can even include drugs which a normal healthy athlete would be disqualified for using. This usually involves getting a specific exception. As you said, "those rules have to be applied uniformly", so why don't we do that? The only question left is whether this individual with his particular setup has an unfair advantage. If its not fair, we adjust it to make it fair, rather than an outright ban. This is no different than setting an allowed dosage for a normal athlete with some serious medical problem. So, please do not treat this differently.
Which is exactly the problem. The line CANNOT be drawn in a different place for different competitors. The rules have to be applied uniformly and fairly. Really? Do they all use the same shoes, clothes, and have the same training technology available to them? It's a complicated line, but its a fixed line; it just has extra dimensions you either don't approve of or didn't know of. Those dimensions are there and they've been there for some time. Look up the story of any athlete coming back after cancer and you'll probably see what I'm talking about.
Everyone appears to be referencing the "unfair advantage" as if it is gospel, yet nobody has offered up a citation. The current ruling overturns the IAAF ruling, which means we should take a hard look at their evidence. On the last slashdot story I didn't find the efficiency evidence provided all that convincing, so I'd like to see more. Nobody here even seems to be trying to do that though, I have yet to see anything cited. It's just assumed to be unfair.
Also, if the advantage is unfair, then I wouldn't have a problem with limiting the devices used to make it fair, rather than an outright ban. Yet nobody here is saying that either. Why this rush to eject this runner from the sport, when all you might have to do is tweak the parameters a bit? It seems like a lot of people aren't content with just a fair race, they want this individual out of the sport.
Much of your argument here also applies to the use of glasses or contacts which the GP mentioned, yet you chose not to address it. So, should glasses be banned? By your argument, I would think so.
The olympics games are supposed to be about what the human body can do, not what the human body can do when given an edge - be it through steroids or bionic limbs. What makes (springy) running shoes and clothing ok?
In particular, the bootloader or the software updater itself. Those are both (1) relatively simple with a fixed problem scope, and (2) more dangerous to update than other software routines.
Not to say it can't be done, it's just highly unlikely to be worth it, so I'd expect those routines to last quite a long time.
DNA is in a more or less constant state of "editing". But yeah, there are trees that are almost 5000 years old which presumably haven't evolved in that time.
No, it's a kdawson article; Based on the summary excerpt:
HP promises blacker blacks and whiter whites the title should read:
HP promotes racism and ethnic cleansing to create racial purity.
Slashdot Mirror
Kenton headed up the open source rewrite, not the original version. The original authors were aware of ASN.1. PBs have backward *and* forward compatibility, a compact wire-format, and try very hard to stay simple. Most other encodings achieve only two out of the three.
Of course, this is probably missing the point. Unless you're doing intensive numerical work, you probably don't need the performance.
...or if you are a company with a large web presence. Using something that runs at half the speed of C++ is not a big deal if you only have 2 servers. However, if you have 1000, then its wasting a lot of money, and it's worth the extra programming time to tune the system. This is kind of why I like OCaml (though I don't get to use it at work), it's a very good balance of a mostly-functional language, speed, and pragmatic features.
A system such as Hawkeye CANNOT BE MORE ACCURATE than humans. From the link in the article, the Hawkeye system uses 5 cameras to compute the 3D position of the ball. That's an overdetermined system of equations, which cannot have a unique solution due to observation errors in the camera views.
Luckily there's a 100+ year old discipline called statistics, and 60+ years of literature on tracking to help you out in these cases.
So Hawkeye has to complement the equations with an ARBITRARY rule, eg least squares and this arbitrariness makes the Hawkeye estimate neither more accurate nor less accurate than humans, just different. FYI, there are plenty of other arbitrary rules that work, eg least absolute errors, maximum entropy, etc.
While I can't speak for the designers of the Hawkeye, in tracking there are very good reasons to choose one form of error minimization versus another. It only seems arbitrary because you are not informed on the subject, but there's plenty of free papers out there to read and discover.
To explain current methods, please start out with this paper, in particular Figure 2, you'll see that the sort of errors you get from a camera are indeed well fit by a Gaussian. While a camera's perspective transformation is not purely linear (and various forms of distortion make it also non-linear), a good camera with a decent lens estimating the ball location within a limited area is well approximated by a linear model (and you can characterize just how much the error is). Now, a bunch of cameras with a Gaussian error distribution in the image plane with a linear projection out into the world is still a Gaussian (with a transformed covariance matrix). You can then multiply the independent measurements from multiple cameras to get a better estimate. Add a time series to that and apply this recursively and you get a Kalman filter, something invented for aerial tracking and still in widespread use today. If something is good enough for missiles to intercept other missiles, it ought to be good enough for a tennis match.
If the linear approximation not good enough for you, you can use a Rao-Blackwellized Kalman filter. If that's still not good enough because you want to use another error distribution or non-linearizable dynamics, set up a particle filter with a whole lot of particles and enough CPU to simulate it. The point is that what you call arbitrary is a well studied field which is many decades old. You'd be best served by learning about it first before you cast away all that work. I'm not a "tracking" person, just a user of there work. When a field of science has done its job well enough that it has become common engineering, and you can go look up whatever you need in books, with all the derivations, caveats and tradeoffs laid out there for you to see, I would say that that field has done a pretty good job.
The whole media story around this paper is ridiculous. It's a paper from a social sciences department about how the public does not understand the fallibility of these machines due to noise. That's all this paper is about: Hawkeye has error. I hate to break it to the uninformed, but all measurement systems have error. From Galileo to Gravity Probe B, your results can only be as accurate as your measurements, calculations, and statistical models will allow. You can decrease error with various methods, but you can never completely eliminate it. People should not be able to get out of high school without understanding accuracy on measurements, and some rudimentary statistics, but unfortunately our education system hasn't been able to reach that goal. As a result, the public doesn't understand error, and might come to believ
Kinda hard to believe he's new with such a low userid ;)
Get off my lawn!Are you sure it didn't say something more like:
INSUFFICIENT DATA FOR MEANINGFUL ANSWER.
That's the Last Question. Someday, it will definitely be worth asking, if we don't kill ourselves off first.
Sure, but it'd make an awesome cautionary tale for other civilizations: Humans, on the brink of disaster due to peak oil, created an organism to solve their engery needs. Unfortunately, it got into the wild, and ended up consuming everything and drowning all surface life in oil.
Yeah, but they both "bring good things to life".
That said, there's a lot of things I fear way more than a backpack nuke as modern-city-life-ending threats, such as ebola[1]. Even those "more likely" threats are remote, and the nuke attack is more movie plot than reality. However, it is not correct to say a man-portable nuke is not possible, when they have already existed for some time. Do you also not believe in weaponized smallpox?
[1] Ebola in different forms has been airborne (Virginia outbreak between monkeys) or highly fatal to humans (most other outbreaks). It's only a matter of time before a strain manages both.
Some people say I've been reading to much Heinlein lately...
Then again maybe not, but if you're going to read too much into TFS, the best I can do is return the favor. Have a nice day
Woolly-minded emotional people think they "probably more or less" cancel out. Scientific minded people think we should measure it and see if it cancels out, to the best of our current scientific ability. Those with the ability to think clearly can see that, if one disabled person is allowed to compete using artificial aids, an arbitrary number of others will in future. Among them, there may well be some world-class athletes who, with prosthetics, will easily beat all "normally abled" athletes. Only if those people have the ability to think but not to calculate. If it can be measured, we can figure out how to make it fair.
In light of that, there are a reasonable fraction of athletes who would willingly sacrifice their future too. Most performance enhancing drugs have very serious negative consequences down the road, and yet you see athletes at almost every level now who willingly make that trade whenever they think they can get away with it. There was an anonymous study once of Olympic hopefuls which asked if they would take a drug if they knew it would guarantee a gold medal, was undetectable, but would kill them in ten years. I can no longer find the reference, but almost unbelievably, a nontrivial fraction of the athletes said they would take the drug. I suspect that people who argue this way don't take the Olympics very seriously. After all, it's just a lot of people playing silly games, isn't it? Besides, many of us nowadays disapprove morally of competition, because most of the competitors must lose. It's often urged how unfair this is, which is why school events are often arranged so that everyone gets prizes. After all, aren't we all very special? No, I just think its fine to adjust things until they are deemed fair. A athlete cancer patient can get all the help they need to get them back to normal, and that's fair as far as I'm concerned. Athletes routinely get exceptions for drugs to treat serious medical conditions, even using drugs that would otherwise be banned. A lot of thought goes into the allowances for exceptions, and they are difficult to get. However its a defined process, and I think the same thing should apply here (and from the looks of it, that's happening). The only downside is that it pretty much destroys the integrity of the Olympic Games. In any competition, loss of integrity is the norm, and the controlling body must constantly struggle to keep it. It's not something to be lost, it is something already lost that we must try to gain and keep with constant maintenance. Looking at exceptional cases on top of the already large burden isn't really that much additional work.
Everyone appears to be referencing the "unfair advantage" as if it is gospel, yet nobody has offered up a citation. The current ruling overturns the IAAF ruling, which means we should take a hard look at their evidence. On the last slashdot story I didn't find the efficiency evidence provided all that convincing, so I'd like to see more. Nobody here even seems to be trying to do that though, I have yet to see anything cited. It's just assumed to be unfair.
Also, if the advantage is unfair, then I wouldn't have a problem with limiting the devices used to make it fair, rather than an outright ban. Yet nobody here is saying that either. Why this rush to eject this runner from the sport, when all you might have to do is tweak the parameters a bit? It seems like a lot of people aren't content with just a fair race, they want this individual out of the sport.
Much of your argument here also applies to the use of glasses or contacts which the GP mentioned, yet you chose not to address it. So, should glasses be banned? By your argument, I would think so.
In particular, the bootloader or the software updater itself. Those are both (1) relatively simple with a fixed problem scope, and (2) more dangerous to update than other software routines.
Not to say it can't be done, it's just highly unlikely to be worth it, so I'd expect those routines to last quite a long time.
DNA is in a more or less constant state of "editing". But yeah, there are trees that are almost 5000 years old which presumably haven't evolved in that time.
Ah, so it's like Emacs?Don't let any company hide the truth from you:
www you tube com / watch? v=Yu_moia-oVI