If you mention that out loud the gubbermint will outlaw all flash memory products whilst braying about "child porn" and "terrorism". That seems to be the default response to any technology that doesn't leave a trail they can follow.
in a controlled environment (inside instead of outside, etc), then, since I can go on forever that way as far as the candle is concerned, a candle has a MTBF in the trillions of years+ ???
Not quite. If you don't experience any failures, then you can't calculate the MTBF because there are no failures to calculate the mean time between. That does not imply infinite reliability, just that not enough data has been collected.
MTBF is not to be confused with life expectancy. MTBF is an indication of reliability. A device (e.g. hard drive) with a MTBF of 100,000 hours is more reliable than one with a MTBF of 50,000. However this does not mean the 100,000 hours MTBF HD will last twice as long as the 50,000 MTBF HD. How long the HD will last is entirely dependent on its life expectancy. An 100,000 MTBF HD can have a life expectancy of 2 years while a 50,000 MTBF HD can have a life expectancy of 5 years yet the HD that's expected to break down after 2 years is still considered more reliable than the 5 years one. Using the 100,000 MTBF HD as an example and putting MTBF together with life expectancy, it means the HD system should on average fail once every 100,000 hours provided it is replaced every 2 years. Another way to look at this is, if there are 100,000 units of this drive and all of them are in use at the same time and any failed drive is put back in working order immediately after the failure, then 1 unit is expected to fail every hour (due to MTBF factor).
People often use MTBF to mean life expectancy, and even within engineering disciplines this is a common misconception. The concept of MTBF is only relevant to certain theoretical models of wear-out anyway, and even though it is quoted for a lot of products it is often a meaningless quantity. The numbers and testing conditions can (as your example shows) be modified to produce just about any MTBF that the tester wants to prove. For most products with a wear-out failure mechanism, Weibull analysis provides a much more accurate estimation of the life span of the product.
Reliability engineering and analysis is hard. It is decidedly counterintuitive sometimes, and most engineers have never been trained in it. It is a massive subject and anyone who has worked in warranty analysis or design for reliability will agree with me, it creates a hell of a lot of work for everyone involved. A lot of it only makes sense when you start looking at large volume production (I design electronics for household appliances - BIG volume - reliability is extremely important). I have been on several training courses about this stuff, and I use it all the time in my daily job, and I still barely understand half of it. That's not because I'm dumb (although this is/. so I'm sure you'll all tell me that I am), but because it is a lifetime's work to become an expert in reliability. Have a look at the work of Dorian Shainin for more information.
Does it matter? As far as I can see it is irrelevant why the system is slow, whether it's slow harware or slow drivers, it's still slow. If nVidia produce better drivers to squeeze more performance out of their hardware then you still get more fps in the end. Does it matter where it comes from? It's not like (at the moment) anyone else is writing better drivers than the manufacturers...
And AFAICS, the statement that "ATI's hardware is better it's just the drivers that let them down" sounds pretty unsubstantiated and unprovable, and more than just a little bit fanboyish...
Police PR: gets citizens to think about policing in a new way and perhaps gain a new respect for the Police.
OK, as a New Zealander, I can tell you that the Police in NZ need all the help they can get in that regard - no-one likes them much at all. Probably because the only time we ever see them is when they're giving out speeding tickets...
Pay rates are higher for contractors, so you don't have to work all year round. You can make enough money in the US or UK in 6 months to take 6 months off in eastern europe or asia easily, no working - just tripping around.
THe downside is that you are also expendable and when the industry comes under pressure you'll be the first to go. It pays to have other skills as a backup plan...
My experience is that trying to convince most office workers to use an application other than Word or Excel for anything is a waste of time. They are comfortable with Word and Excel, anything else is new and scary.
So it would appear that Slasdot has spoken, and that most are trying to tell you that computers have no place in the maths / physics classroom. But that wasn't what you asked. What you were really asking, it seems to me, was "I have these cool tech toys, how can I incorporate them into my lessons?" First of all, you have listed 3 subjects which you are/will be teaching, potentially with the aid of this equipment. I had typed out a great long post here, but really it boiled down to "Algebra and Calc are not going to benefit from this much more than using it as a glorified OHP that can show moving pictures". By all means use it if it's more convenient than an OHP though.
I think there is potentially a benefit to be had in Physics lessons, where there are often concepts which are taught in simple forms, then experiments which have extra constraints on them are used to prove the concepts. Friction or electrical resistance are good examples of uncontrolled parameters which cannot be removed in reality. If you can show simulations of physical systems, and add in elements as you go, then you can potentially build up a better understanding of what parts of the system contribute what effects. Take for example series resonance - (either Mass-Spring-Damper or LCR circuit). In the real world it is impossible to build a system to demonstrate LC or Mass Spring resonance without any form of damping. But on a computer, easy. Arbitary amounts of friction/resistance can be added as you go, to show what the effect is.
That is obviously only one example of how a simulation could be used, and I would think that just about every concept that is taught at a High School physics level could be simulated easily. A lot of excersises in physics text books are perfect examples of things that could be simulated - especially the ones which say things like "Assuming there is no air friction" or other such assumptions which are hard to replicate in real experiments. Students could be asked to calculate parameters for the simulations (the same as the would for real experiments) in order to acheive certain goals - eg. calculate values of L R and C to give a certain frequency of oscillation and damping factor. The ability to test them with a simulator would show quickly and easily if they are correct, without relying on what parts you have available at the time.
It is important to note that these simulations would absoulutely NOT replace hands-on experiments by the students, and in fact should probably be done after the students have already collected their own results - so as not to give the game away first. But simulation is an important tool in engineering (applied physics!) these days, so I see no problem with using it in the classroom, as long as it is used as a tool for learning, not a crutch. As for my recommendations of what software to use - that really depends on you and your level of knowledge about computers and programming. I will assume that as you are posting to Ask/. that you have some level of programming experience (bad assumption?) so I would recommend VPython and SciLab (or FreeMAT) for physical simulations. Some of the simulations at http://www.myphysicslab.com/ might give you some ideas of the sorts of things I'm thinking about. And I would say that a bit of thought at the outset as to what you are trying to achieve with each simulation will go a long way. Make them able to accept parameters so that you can easily show what happens when you change things. If your programming knowledge is less, there are systems such as Interactive Physics which may be of some use, I don't know, I've never tried it (just googled it).
Lets cut to the chase - these drives are not designed for corporate security. Biometrics are not up to that yet, for all the reasons that people have posted above.
These "thumbprint" flash drives are for keeping snoopers from seeing what's on your thumb drive while being quicker and easier than a password system (nothing to remember). But mostly they're just a gimmick. Good for hiding pr0n from your mum, not much more..
Assuming that you accelerate and decelerate at the same rate you can keep accelerating all the way to the half-way point between departure and destination right? SF to London ~= 8000km So you have 4000km to accelerate in right?
dV = sqrt(2*a*d) (assuming constant acceleration...)
Given an acceleration of 0.25G which I'm sure is not more than anyone could take, given that they are exposed to 1G their entire lives, and given that the aircraft starts stationary:
dV = sqrt(2 * a * d) = sqrt(2 * (0.25 * 9.81) * 4e6) = 4.43e3 m/s = mach 13.4
By my calcs it would only take 1000km accelerating at this rate to get to mach 7. So you could cruise for the next 6000km at mach 7, then slow down for landing in the last 1000km.
(Someone check my calcs and make sure I'm not full of shit...)
... except that the platform it runs on is Mozilla. Just because the platform isn't an OS doesn't mean it's independant.
It won't even try to run on Opera, so AFAIAC it might as well not work at all. And come on, locking out IE? Doesn't that lock out MOST of the market????
You would be surprised by the number of developers that I know that developed their apps using MySQL and then had to pay for the comercial license many months later because they didn't read the fine print.
Then they are idiots aren't they?
Seriously, how could you go through the whole of the MySQL site to get to the download, without noticing the words "purchase", "buy", and "license" all over the show? Even if you hadn't read the license (which I still maintain makes you an idiot if you plan on using it commercially) the site is more than explicit about the dual licensing scheme.
MySQL Products are available under the "dual licensing" model. Under this model, users may choose to use MySQL products under the free software/open source GNU General Public License (commonly known as the "GPL") or under a commercial license. ISVs and Resellers, who are embedding and reselling MySQL as part of their own commercial solutions, can purchase a MySQL commercial license.
Oh, and the people that modded me troll - apparently I'm right and you really have never heard of usenet.../. is a real good place to get opinions, not facts.
There are more appropriate places to ask this...
on
Arrays vs Pointers in C?
·
· Score: 0, Troll
Quite a few comments have already been made about allowing modding. Add to that a really good story in the original game / campaign / whatever and you're getting close to a good thing.
Whilst I am not an expert game designer, or even a very talented gamer, I do know which games have kept me coming back time and again. In no particular order: Neverwinter Nights, No-One Lives Forever, Soldier of Fortune II Double Helix.
The storylines in those games were involving. It's a bit like an interactive book or movie. That analogy carries through into the modding argument as well. Actively encourage budding authors/scriptwriters/game designers to use your game as their medium and you have a good chance of attracting some fairly serious community response.
One of the links in the OP goes to a site for the deafblind (ie both hearing and visually impaired).
Kind of makes it a bit harder I think because a lot of the solutions for blind people hinge on using sound to compensate for the lack of visual communication. If you also have that sense removed or impaired that would make it a lot harder.
Slashdot Mirror
SSSHHHH!!!!
If you mention that out loud the gubbermint will outlaw all flash memory products whilst braying about "child porn" and "terrorism".
That seems to be the default response to any technology that doesn't leave a trail they can follow.
Not quite. If you don't experience any failures, then you can't calculate the MTBF because there are no failures to calculate the mean time between. That does not imply infinite reliability, just that not enough data has been collected.
From Wikipedia:
People often use MTBF to mean life expectancy, and even within engineering disciplines this is a common misconception. The concept of MTBF is only relevant to certain theoretical models of wear-out anyway, and even though it is quoted for a lot of products it is often a meaningless quantity. The numbers and testing conditions can (as your example shows) be modified to produce just about any MTBF that the tester wants to prove. For most products with a wear-out failure mechanism, Weibull analysis provides a much more accurate estimation of the life span of the product.
Reliability engineering and analysis is hard. It is decidedly counterintuitive sometimes, and most engineers have never been trained in it. It is a massive subject and anyone who has worked in warranty analysis or design for reliability will agree with me, it creates a hell of a lot of work for everyone involved. A lot of it only makes sense when you start looking at large volume production (I design electronics for household appliances - BIG volume - reliability is extremely important). I have been on several training courses about this stuff, and I use it all the time in my daily job, and I still barely understand half of it. That's not because I'm dumb (although this is
I am told that many teachers developed chalk dust allergies in the days of blackboards. Whiteboards are also easier to clean.
However, I remember blackboards from my primary school days, and I don't seem to remember there being any problem with them.
More like once you install Linux on your machine the warranty is void. Which I think you will find is actually common practice.
Does it matter? As far as I can see it is irrelevant why the system is slow, whether it's slow harware or slow drivers, it's still slow. If nVidia produce better drivers to squeeze more performance out of their hardware then you still get more fps in the end. Does it matter where it comes from? It's not like (at the moment) anyone else is writing better drivers than the manufacturers...
And AFAICS, the statement that "ATI's hardware is better it's just the drivers that let them down" sounds pretty unsubstantiated and unprovable, and more than just a little bit fanboyish...
Police PR: gets citizens to think about policing in a new way and perhaps gain a new respect for the Police.
OK, as a New Zealander, I can tell you that the Police in NZ need all the help they can get in that regard - no-one likes them much at all. Probably because the only time we ever see them is when they're giving out speeding tickets...
I'll take number 4. 4 is so much more rock and roll.
Contracting.
Pay rates are higher for contractors, so you don't have to work all year round. You can make enough money in the US or UK in 6 months to take 6 months off in eastern europe or asia easily, no working - just tripping around.
THe downside is that you are also expendable and when the industry comes under pressure you'll be the first to go. It pays to have other skills as a backup plan...
My experience is that trying to convince most office workers to use an application other than Word or Excel for anything is a waste of time. They are comfortable with Word and Excel, anything else is new and scary.
So it would appear that Slasdot has spoken, and that most are trying to tell you that computers have no place in the maths / physics classroom. But that wasn't what you asked. What you were really asking, it seems to me, was
/. that you have some level of programming experience (bad assumption?) so I would recommend VPython and SciLab (or FreeMAT) for physical simulations. Some of the simulations at http://www.myphysicslab.com/ might give you some ideas of the sorts of things I'm thinking about. And I would say that a bit of thought at the outset as to what you are trying to achieve with each simulation will go a long way. Make them able to accept parameters so that you can easily show what happens when you change things. If your programming knowledge is less, there are systems such as Interactive Physics which may be of some use, I don't know, I've never tried it (just googled it).
"I have these cool tech toys, how can I incorporate them into my lessons?"
First of all, you have listed 3 subjects which you are/will be teaching, potentially with the aid of this equipment. I had typed out a great long post here, but really it boiled down to "Algebra and Calc are not going to benefit from this much more than using it as a glorified OHP that can show moving pictures". By all means use it if it's more convenient than an OHP though.
I think there is potentially a benefit to be had in Physics lessons, where there are often concepts which are taught in simple forms, then experiments which have extra constraints on them are used to prove the concepts. Friction or electrical resistance are good examples of uncontrolled parameters which cannot be removed in reality. If you can show simulations of physical systems, and add in elements as you go, then you can potentially build up a better understanding of what parts of the system contribute what effects. Take for example series resonance - (either Mass-Spring-Damper or LCR circuit). In the real world it is impossible to build a system to demonstrate LC or Mass Spring resonance without any form of damping. But on a computer, easy. Arbitary amounts of friction/resistance can be added as you go, to show what the effect is.
That is obviously only one example of how a simulation could be used, and I would think that just about every concept that is taught at a High School physics level could be simulated easily. A lot of excersises in physics text books are perfect examples of things that could be simulated - especially the ones which say things like "Assuming there is no air friction" or other such assumptions which are hard to replicate in real experiments.
Students could be asked to calculate parameters for the simulations (the same as the would for real experiments) in order to acheive certain goals - eg. calculate values of L R and C to give a certain frequency of oscillation and damping factor. The ability to test them with a simulator would show quickly and easily if they are correct, without relying on what parts you have available at the time.
It is important to note that these simulations would absoulutely NOT replace hands-on experiments by the students, and in fact should probably be done after the students have already collected their own results - so as not to give the game away first. But simulation is an important tool in engineering (applied physics!) these days, so I see no problem with using it in the classroom, as long as it is used as a tool for learning, not a crutch.
As for my recommendations of what software to use - that really depends on you and your level of knowledge about computers and programming. I will assume that as you are posting to Ask
Anyway, that's my 2c worth, I wish you luck
AJ
Avionics != Military
There are a LOT of civilian aircraft
Lets cut to the chase - these drives are not designed for corporate security. Biometrics are not up to that yet, for all the reasons that people have posted above.
These "thumbprint" flash drives are for keeping snoopers from seeing what's on your thumb drive while being quicker and easier than a password system (nothing to remember). But mostly they're just a gimmick. Good for hiding pr0n from your mum, not much more..
You just made that up, and guess what - it's 100% wrong.
The correct answer (strobe effect) is given by another poster above.
Sounds like someone got fragged a lot as a child...
Assuming that you accelerate and decelerate at the same rate you can keep accelerating all the way to the half-way point between departure and destination right?
SF to London ~= 8000km
So you have 4000km to accelerate in right?
dV = sqrt(2*a*d) (assuming constant acceleration...)
Given an acceleration of 0.25G which I'm sure is not more than anyone could take, given that they are exposed to 1G their entire lives, and given that the aircraft starts stationary:
dV = sqrt(2 * a * d)
= sqrt(2 * (0.25 * 9.81) * 4e6)
= 4.43e3 m/s
= mach 13.4
By my calcs it would only take 1000km accelerating at this rate to get to mach 7. So you could cruise for the next 6000km at mach 7, then slow down for landing in the last 1000km.
(Someone check my calcs and make sure I'm not full of shit...)
... except that the platform it runs on is Mozilla. Just because the platform isn't an OS doesn't mean it's independant.
It won't even try to run on Opera, so AFAIAC it might as well not work at all. And come on, locking out IE? Doesn't that lock out MOST of the market????
Then they are idiots aren't they?
Seriously, how could you go through the whole of the MySQL site to get to the download, without noticing the words "purchase", "buy", and "license" all over the show? Even if you hadn't read the license (which I still maintain makes you an idiot if you plan on using it commercially) the site is more than explicit about the dual licensing scheme.
From http://dev.mysql.com/downloads/mysql/5.0.html
If you use anyone elses IP as part of your product without checking that you have licence to do so you are asking for it.
I expected this the be the FIRST post... What is /. coming to?
Hence the suggestion of a .moderated group.
/. is a real good place to get opinions, not facts.
Oh, and the people that modded me troll - apparently I'm right and you really have never heard of usenet...
Such as comp.lang.c.moderated
Do the kids still know what USENET is?
(XNews is still the best newsreader BTW...)
Quite a few comments have already been made about allowing modding.
Add to that a really good story in the original game / campaign / whatever and you're getting close to a good thing.
Whilst I am not an expert game designer, or even a very talented gamer, I do know which games have kept me coming back time and again. In no particular order: Neverwinter Nights, No-One Lives Forever, Soldier of Fortune II Double Helix.
The storylines in those games were involving. It's a bit like an interactive book or movie. That analogy carries through into the modding argument as well. Actively encourage budding authors/scriptwriters/game designers to use your game as their medium and you have a good chance of attracting some fairly serious community response.
I'll agree that American English should probably have a better more unambiguous term.
;)
It does: "Wrong."
No, there is right and there is wrong. Correct spelling and grammer are right.
And you are wrong.
One of the links in the OP goes to a site for the deafblind (ie both hearing and visually impaired).
Kind of makes it a bit harder I think because a lot of the solutions for blind people hinge on using sound to compensate for the lack of visual communication. If you also have that sense removed or impaired that would make it a lot harder.
only if you're an AC...
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