power supply efficiency
on
Port-A-Nuke
·
· Score: 1
The power rating of the PSU is how much power it *can deliver*, not how much it will drain from the grid just because you plug it in.
True, but power supplies aren't always very efficient. Quoting this web page:
While the best power supplies are more than 90% efficient, some are only 20 to 40% efficient, wasting the majority of the electricity that passes through them. As a result, today's power supplies consume at least 2% of all U.S. electricity production. More efficient power supply designs could cut that usage in half, saving nearly $3 billion and about 24 million tons of carbon dioxide emissions per year.
Here's some more info from the energystar website:
EPA's research has indicated that approximately one-third of the electricity that flows through power supplies is consumed in the power supply itself. On average, these power supplies are only about 50 to 70% efficient, wasting 30 to 50% of the electricity flowing through them. Overall, 2 to 3% of US electricity could be saved through the use of more efficient power supplies.
Evil thought: Apple should include a "three silhouettes yakking on merged soundtrack" mode in iMovie.
I like that idea (if they can do it in such a way as to not infringe on MST3Ks rights, whatever those might be).
It would be a great way to do MST3K-format parodies of regular high-budget films without infringing the copyright of those high-budget films - you would have to buy the original, then watch it with overlaid video and audio. It's even good for sales of the movie being parodied.
Can you imagine watching the march of the ents in The Two Towers, while silouettes of Radagast, the Gaffer, and Cirdan in the corner yell "Run, forest, run!*", or shouts of agreement when Frodo says "We're not even supposed to be here." in Osgiliath?
Can mplayer do this? Does mpeg allow transparency (though, if it's a sillouette, you could use white for transparent)?
*I'm not clever enough to have thought up this forrest gump reference myself, I read it in some random slashdot post long ago, but I thought it would illustrate the point quite well.
Why don't you just put your degrees based objects below a transformation?
Uh, that only works with length units, not angle. You can say "let's make this group of things 10 times bigger", but you can't say "let's rotate these things 0.017453292519942779 times as much as they've previously been rotated". At least, you can't express that in terms of rotate, scale, and translate operations. It may be possible with a transformation matrix, but I don't think so.
Or use a calculator.
Sure, you can use a calculator to translate to and from your favorite angle units, but it doesn't lend itself to readable code. As a user, I'd rather see "90" than "1.5707963267948499". The point is moot if no user is ever going to look at or edit the model directly with a text editor, but if there's some possibility that they might, why make it hard for no reason?
Dude, radians are freakin easy when you look at them the right way. Two PI = 360 degrees. Thus 180 degrees = PI, 90 degrees = PI/2, 45 degrees is PI/4, 60 degrees is PI/3, and 30 degrees is PI/6. When you keep it in terms of PI, radians are easy to work with.
Any unit is easy when used with a constant to convert it to some other unit. Used raw, they're horrible. Who wants to remember that 1.0471975511965665 radians is almost but not quite one sixth of a revolution? Is it even possible to use basic math (such as multiplying by a constant) inside an X3D or VRML file?
I realize that these 3d model formats were meant to be written and read by programs, not humans, but why make it unwritable and unreadable to humans when you don't have to?
Since the choice of which unit to use is rather ambiguous, I think the mathematical ease of radians breaks the tie in the end.
Why not let the programmer choose, by writing an angle as either, say, 3.14159r or 180d, the same way we write 0x10 and 16 to mean the same thing in c?
Evidently, there's a lot more die-hard radian fans out there than I anticipated (whose wrath I have unwittingly provoked). The only practical uses for radians I can see are a)converting them to the format used by the c trig routines, and b)specifying the rotation and translation of a wheel rolling along a flat surface. I've written many thousands of lines of pov-ray code, and have never once felt a desire to specify anything in radians, though I do occasially tend to prefer to specify rotation as fractions of a complete revolution, as in: rotate y*360*(1/3) to rotate an object 1/3 of a revolution along the y axis. This is not much different than rotate y*(pi*2)*(1/3), so either works fine as long as the language allows embedded math (I don't think VRML did, but it's been a long time since I used it, and I didn't know the language very well).
Also, you have to realize that the editing won't likely won't be done by hand, so all that need be done is have the modeling program convert from degrees (if that's your preference).
I'm one of those weird people that likes to edit graphics files by hand (though it's much easier in POV-Ray than anything else I've tried, thanks to real programming constructs, CSG operations, and a nice, concise systax).
Try doing calculus-based physics for a while, then toss your conceptions about radians being a mere matter of convention out the window.
I thought this was a discussion of 3d model formats? Granted, some 3d models may be output from a physics model, but it's a lot easier to multiply all the angles by 180/pi when they're output by a physics program than it is to force programmers to write and understand code that expects irrational numbers with many decimal places of accuracy for simple things like arranging six copies of an object so they're radially symetrical
If you really care, it's a piece of cake to write a script that'll translate all the degrees in your hand-made model into radians.
It's also a piece of cake to write a script that converts hex, octal, and decimal numbers into binary, but for some reason, the designers of most programming languages allow users to enter numbers in whatever format is most convenient to them.
Seriously, if you're taking the time to write 3-D models by hand, you can spare an hour to work out a translating solution. The rest of us have real work to do and we need radians.
Why add a "compile" step to the edit model, view model process for no good reason? We don't compile plain hand-written html, why should we compile vrml or x3d?
One of my gripes with vrml is that angles are specified in radians, and it looks like x3d is the same. Maybe it makes the transform math simpler, but Arghhh! Who in the world decided that radians were more intuitive to work with than degrees? Do they think no one will ever write 3d models by hand? I like to have "turn this a quarter turn" work out to a rational number.
Maybe there's some way to set the default input mode to degrees, and someone will enlighten me.
After last week's discussion of cdrecord, and concerns that recent releases of cdrecord may not be free software, we decided to take a look and see what alternatives exist for Linux users. The answer, unfortunately, is "not many." While there are quite a few front-ends for recording CDs under Linux, there are very few actual CD and DVD-burning applications available to Linux users. Applications like K3b, MP3Roaster, BashBurn and others all use cdrecord to burn CDs.
3. An air marshal with a pistol or uzi and rubber bullets (no hull penetration) sits here, facing the passengers.
Nitpick: maybe it would be better if none of the passengers knew where the air marshal was sitting.
-jim
Re:Nice, but they've got it all wrong...
on
Linux Desktop Guide
·
· Score: 4, Insightful
So is the chance that people's very first system will be Linux high? No.
Does this make this whole thing pointless? Yes.
Perhaps the lack of good documentation is keeping first time users away from Linux? Maybe if we fix the things that drive users away, we'll have a bigger user base? It seems to me that a high quality system that isn't attracting novice users ought to think about producing good documentation. You certainly haven't demonstrated that it is pointless.
only Microsoft can destroy their own monopoly.
And the linux community needs to be ready to absorb those users when it happens. Some might say it's already happening, or that it's inevitable.
We need to find a way to deal with it, and this is not it.
Why not? Just because linux doesn't attract many casual users doesn't mean we should assume they don't exist, nor should we criticize efforts to attract casual users. Certainly other things need to be worked on as well (useability, more robust configuration tools, etc...), but not everyone is a coder, and not every problem is fixed with code.
-jim
Re:this looks like a job for...Google Cache!
on
Linux Desktop Guide
·
· Score: 4, Informative
Perhaps, just perhaps, there is a solution. It might not be impossible to have anonymous open-source, with guaranteed anonymity provided much the same way the Cypherpunks' MixMaster remailer network works. That way, one could contribute to open-source projects, and share the benefits of your work with others, without exposing yourself to patent suits.
This protects the authors of the code, but if I understand correctly, a user could still be sued for using a product that infringes someone's patents. The real (very difficult) solution is to fix patent law.
Wow, Syzygy really is a word. Somehow, I don't remember that one from the decade-old high school science corner of my brain. That's almost as good as Xyzzy.
Once you get used to the language, it's not that hard to make good looking, complicated stuff. Povray has dozens of built in geometric primitives, CSG support (you can subtract objects from each other), loops, and macros (which can be invoked recursively to generate things like trees). Some things are easier to make in a gui modeller, but many things are actually easier to code directly.
The scripting language is really not all that bad (especially compared to VRML, the other graphics scripting language I've used). You can build complex objects by generating them within loops or recursive macro calls - you can make a halfway decent looking tree in less than a page of code. If you're used to pointing and clicking, it can be a pain, but some things that would be near impossible to create in gui modeller are easy to program.
CSG helps the user friendliness quite a bit. With ray tracers, it's algorithmically trivial to subtract one object from another, so they expose those capabilities to the user.
Here's something I did. Except for the jolly roger (which you can't really see anyways) and one of the textures, it's all code, even the lumpy rocks.
80% of WiFi Networks are still Unsecure, Kismet Author Says
from the article:
Despite all the press about it, the overall percentage of unencrypted networks is still at about 80%
An insecure network and an unencrypted network are not the same thing. WEP is encrypted, yet insecure, while secure IMAP and SSH are secure by providing end to end encryption, instead of relying on the network to provide it.
The big problem with the Zeitgeist stats, from what I've heard, is that they only recorded the same IP address once.
Since the article is slashdotted, I wondered what the issue was. I've always thought 1% seemed kind of low. It seems like it would be reasonable to record a tally for each OS once per query to reflect actual useage (unless they're worried about some OS zealot setting wget to query their service once per second to inflate their numbers).
Slashdot Mirror
True, but power supplies aren't always very efficient. Quoting this web page:
There's a bit more information at wikipedia, but I don't see any hard numbers.
Here's some more info from the energystar website:
-jim
Here's the wikipedia article for pebble bed reactors, including a discussion of their safety.
-jim
I like that idea (if they can do it in such a way as to not infringe on MST3Ks rights, whatever those might be).
It would be a great way to do MST3K-format parodies of regular high-budget films without infringing the copyright of those high-budget films - you would have to buy the original, then watch it with overlaid video and audio. It's even good for sales of the movie being parodied.
Can you imagine watching the march of the ents in The Two Towers, while silouettes of Radagast, the Gaffer, and Cirdan in the corner yell "Run, forest, run!*", or shouts of agreement when Frodo says "We're not even supposed to be here." in Osgiliath?
Can mplayer do this? Does mpeg allow transparency (though, if it's a sillouette, you could use white for transparent)?
*I'm not clever enough to have thought up this forrest gump reference myself, I read it in some random slashdot post long ago, but I thought it would illustrate the point quite well.
-jim
Uh, that only works with length units, not angle. You can say "let's make this group of things 10 times bigger", but you can't say "let's rotate these things 0.017453292519942779 times as much as they've previously been rotated". At least, you can't express that in terms of rotate, scale, and translate operations. It may be possible with a transformation matrix, but I don't think so.
Sure, you can use a calculator to translate to and from your favorite angle units, but it doesn't lend itself to readable code. As a user, I'd rather see "90" than "1.5707963267948499". The point is moot if no user is ever going to look at or edit the model directly with a text editor, but if there's some possibility that they might, why make it hard for no reason?
-jim
Any unit is easy when used with a constant to convert it to some other unit. Used raw, they're horrible. Who wants to remember that 1.0471975511965665 radians is almost but not quite one sixth of a revolution? Is it even possible to use basic math (such as multiplying by a constant) inside an X3D or VRML file?
I realize that these 3d model formats were meant to be written and read by programs, not humans, but why make it unwritable and unreadable to humans when you don't have to?
-jim
Why not let the programmer choose, by writing an angle as either, say, 3.14159r or 180d, the same way we write 0x10 and 16 to mean the same thing in c?
Evidently, there's a lot more die-hard radian fans out there than I anticipated (whose wrath I have unwittingly provoked). The only practical uses for radians I can see are a)converting them to the format used by the c trig routines, and b)specifying the rotation and translation of a wheel rolling along a flat surface. I've written many thousands of lines of pov-ray code, and have never once felt a desire to specify anything in radians, though I do occasially tend to prefer to specify rotation as fractions of a complete revolution, as in: rotate y*360*(1/3) to rotate an object 1/3 of a revolution along the y axis. This is not much different than rotate y*(pi*2)*(1/3), so either works fine as long as the language allows embedded math (I don't think VRML did, but it's been a long time since I used it, and I didn't know the language very well).
I'm one of those weird people that likes to edit graphics files by hand (though it's much easier in POV-Ray than anything else I've tried, thanks to real programming constructs, CSG operations, and a nice, concise systax).
-jim
I thought this was a discussion of 3d model formats? Granted, some 3d models may be output from a physics model, but it's a lot easier to multiply all the angles by 180/pi when they're output by a physics program than it is to force programmers to write and understand code that expects irrational numbers with many decimal places of accuracy for simple things like arranging six copies of an object so they're radially symetrical
It's also a piece of cake to write a script that converts hex, octal, and decimal numbers into binary, but for some reason, the designers of most programming languages allow users to enter numbers in whatever format is most convenient to them.
Why add a "compile" step to the edit model, view model process for no good reason? We don't compile plain hand-written html, why should we compile vrml or x3d?
-jim
One of my gripes with vrml is that angles are specified in radians, and it looks like x3d is the same. Maybe it makes the transform math simpler, but Arghhh! Who in the world decided that radians were more intuitive to work with than degrees? Do they think no one will ever write 3d models by hand? I like to have "turn this a quarter turn" work out to a rational number.
Maybe there's some way to set the default input mode to degrees, and someone will enlighten me.
-jim
Anyone see any more on that list that are public domain?
-jim
I believe it only needs one if it has a transmitter. If the antenna is receive-only it probably doesn't need one.
-jim
Nitpick: maybe it would be better if none of the passengers knew where the air marshal was sitting.
-jim
Perhaps the lack of good documentation is keeping first time users away from Linux? Maybe if we fix the things that drive users away, we'll have a bigger user base? It seems to me that a high quality system that isn't attracting novice users ought to think about producing good documentation. You certainly haven't demonstrated that it is pointless.
And the linux community needs to be ready to absorb those users when it happens. Some might say it's already happening, or that it's inevitable.
Why not? Just because linux doesn't attract many casual users doesn't mean we should assume they don't exist, nor should we criticize efforts to attract casual users. Certainly other things need to be worked on as well (useability, more robust configuration tools, etc...), but not everyone is a coder, and not every problem is fixed with code.
-jim
Not bit torrent, but it'll have to do...
Google Cache
-jim
This protects the authors of the code, but if I understand correctly, a user could still be sued for using a product that infringes someone's patents. The real (very difficult) solution is to fix patent law.
-jim
Wow, Syzygy really is a word. Somehow, I don't remember that one from the decade-old high school science corner of my brain. That's almost as good as Xyzzy.
-jim
Nistnet is another tool that simulates delay.
-jim
Maybe we can make slashdot history here twice. What's the record for most replies to a post? We're at 53 so far...
-jim
Yeah, it's a little too dark. (It looks okay on some monitors.) Try this one.
Most of the irtc entrants publish their code. I just uploaded my code here, and there's a better rendering here
-jim
Once you get used to the language, it's not that hard to make good looking, complicated stuff. Povray has dozens of built in geometric primitives, CSG support (you can subtract objects from each other), loops, and macros (which can be invoked recursively to generate things like trees). Some things are easier to make in a gui modeller, but many things are actually easier to code directly.
Here's something I've been working on. It's all code except for one of the textures and the Jolly Roger on the boat.
-jim
The scripting language is really not all that bad (especially compared to VRML, the other graphics scripting language I've used). You can build complex objects by generating them within loops or recursive macro calls - you can make a halfway decent looking tree in less than a page of code. If you're used to pointing and clicking, it can be a pain, but some things that would be near impossible to create in gui modeller are easy to program.
CSG helps the user friendliness quite a bit. With ray tracers, it's algorithmically trivial to subtract one object from another, so they expose those capabilities to the user.
Here's something I did. Except for the jolly roger (which you can't really see anyways) and one of the textures, it's all code, even the lumpy rocks.
-jim
from the post:
from the article:
An insecure network and an unencrypted network are not the same thing. WEP is encrypted, yet insecure, while secure IMAP and SSH are secure by providing end to end encryption, instead of relying on the network to provide it.
-jim
Since the article is slashdotted, I wondered what the issue was. I've always thought 1% seemed kind of low. It seems like it would be reasonable to record a tally for each OS once per query to reflect actual useage (unless they're worried about some OS zealot setting wget to query their service once per second to inflate their numbers).
-jim
disregard parent, I confused myself. grandparent is correct.