On SSDs, the tables used for wear-leveling get fragmented over time. One trick that works with almost all SSD models is to do a sequential write of every logical block, _twice_. That will result in unfragmented tables. It might work on thumb drives too, but remember to do it twice. Try this:
dd if=/dev/zero of=/path/to/usb/drive
dd if=/dev/zero of=/path/to/usb/drive
I am doing exactly what the OP wants to do. I've been living in my RV (29' 5th wheel trailer) for 6 months, and I'm typing this post over my satellite connection from the northern Cascade mountains in Washington. Here is what I have learned:
1) Satellite is the only way to go when you get out in the boonies. When we started this trip, I had an Openmoko phone as a backup ISP, but I dropped the data plan 2 months later because I almost never had connection.
2) Hughesnet is the only affordable satellite provider. Some other companies resell Hughesnet service. I use Motosat, which caters to the RV market. You will probably have to use a reseller, as Hughesnet's own TOS doesn't allow mobile use and they don't want you as their customer.
3) You can get an ordinary residential Hughesnet dish and mount it on a tripod, but aiming that dish is a royal PITA. www.maxwellsatellite.com sells dish, tripod, and pointing gear as a combo for IIRC $500. But it's still a PITA to point (the record holder from their user's group did it in 5 minutes), and vulnerable to theft. I wouldn't consider it an option if you are going to be moving frequently. A better setup is a roof mounted tracker, like what Motosat makes. Their motorized, and usually acquire the satellite in under 5 minutes with no help from the user. But you're going to have to pay: new systems cost $5k. I got mine used off eBay and installed it myself for $2k. Soldering Iron not required, but expect to cut and crimp a little cable, and of course you have to do the roof mounting. The hardest part was lifting the dish up onto the roof, because it's 80lbs with mount.
4) Contrary to what some other poster said, these dishes are NOT comparable size to TV dishes. They are larger, because they need to transmit info back to the bird. They start at 0.74m diameter. This means that pointing them is harder than pointing a TV dish, and they absolutely cannot be used while in motion.
5) Do not buy an RV with a rubber roof. Just don't.
6) Are you using solar power? I do, and it's worked out quite well. I could give you some tips if you want.
My recommendation would be Hughesnet with a motorized tracker, and a 3G phone if you need connection while moving on the highways. You can learn more about my experiences with the technomadic lifestyle at http://lauralan.livejournal.com/
Water vapor would be a powerful greenhouse gas, if there weren't already so much of it there. Basically, our atmosphere has so much water vapor, that every frequency of IR that can be absorbed by it is already fully absorbed. So more water vapor won't make a difference. CO2 and CH4, on the other hand, are potent greenhouse gasses because not only do they absorb IR, but they're pretty scarce our atmosphere.
Let's do the math, but starting from different angle. Really cheap electricity is $0.10/kWh, and the fuel station will probably charge a 30% markup at a minimum, for $0.13/kWh. For $3.00, if the air compressor is 100% efficient and there are no resistive losses involved with charging the tank, and you charge it at constant temperature you can store 23kWhr. In reality it would store less because the air would heat up as it compresses, then cool down after you leave the pump. The pressure would drop as it cools, so you'd be paying for pressure that you never get to use. The most fuel efficient cars today are hybrids that get 70mpg under very favorable conditions. Gasoline has 34.6MJ/liter (http://en.wikipedia.org/wiki/Gasoline), so if the Prius is 48% efficient (http://www.uwgb.edu/dutchs/EarthSC102Notes/102Ene rgy.htm) it will take 70mpg / 34.6MJ/l / 48% * 3.785gal/l * 1.6km / mile = 25.5km/MJ . With our cheap power, that comes out to 25.5km/MJ * 0.278 MJ/kWh / $0.13/kWh = 54.6 km/$ , or $5.49/300km . So expecting to travel 300km with only $3.00 worth of fuel would require you to invent a 100% efficient compressed air powertrain, get really cheap power, and double the efficiency (post-engine) of modern cars. Not bloody likely.
We can also calculate the pressure and maximum size of the fuel tank if we remember that PV=nRT and W = integral(P, dV). Solving for constant temperature charging gives W = nRT_initial - lnV |(V_initial - V_final) . Traveling 300km with the above figures requires storing 11.76MJ. I get 24.8m for the maximum tank size that would still be high enough pressure. But that's bigger than the car. A 50 gallon tank is probably about the biggest you could fit in that tiny car, and this would be only 0.187 cubic meter. Such a tiny tank could theoretically store 56MJ. If that is indeed their tank size, then the car might actually work with realistically efficient parts. But from Boyle's law the pressure would be 500atm!
The reason linux distros are so different, on PCs or on cell phones, is that open source apps don't need a standardized environment and linux is made to work with open source apps. If your application uses autoconf, it's pretty darn easy to port to any distro. But have you ever tried installing matlab, lexmark printer drivers, or games? Closed source software like that has arcane installers that only work on red hat and have to be reverse engineered for other distros. The people who want linux to "standardize" are the people who want to sell closed source apps. "Standardization" would hurt those who use only FOSS because it would greatly reduce choice in your distros. FOSS is the core function of linux (that's the GNU in GNU/Linux). Linux should not cripple itself to make room for non-free software.
I don't speak German and I don't know German law, but it seems to me that the crucial change behind this plan is that downloading will be criminalized. In the US only uploading (copying & distributing) is illegal. Making it a crime just to possess information has serious free speech ramifications. Does anyone know if downloading is illegal in Germany today?
You can use your smartphone to annoy telemarketers. Just write a program that analyzes the power per unit time of the conversation to detect pauses. When the telemarketer pauses, the program plays an interjection like "yeah" or "uh huh" or "I don't understand".
When your phone rings and you answer it and hear a telemarketer, press the "spam" button and put the phone away, secure in the knowledge that your program will waste a minute or so of the spammer's time.
You miss one important difference between google and experian: Google is a tool to put public data into private hands; Experian puts (what should be) private data into public hands. Both are legal, but in a society with a right to privacy Experian wouldn't be. Our founding fathers didn't anticipate Experian, or they probably would've put a Privacy Amendment into the Bill of Rights. It's a damn shame they didn't.
Dude, learn the difference between temperature and heat. It takes an equal amount of heat to heat 1 gram of H2 to 1 billion degrees as it does to heat 10 grams of H2 to 100 million degrees (ignoring the effects of the plasma phase transistion; IANA(N/P)P ). His device operates on a very small scale. Very little H2 involved, means very little heat energy required. Also, it doesn't say that the copper electrodes ever get that hot. They wouldn't, because there isn't much gas involved, there isn't much time for heat transfer, and those magnetic fields ought to be designed to focus the plasma away from the electrodes. I'm not saying that this thing will work as well as Dr. Lerner says it will, but your criticisms are at least as bogus as his claims.
I always thought step 2 was the hard part, because it requires methanol (biodiesel is basically a methanol-fatty acid ester), and methanol is tough to make. It gets made by cracking petroleum catalytically at very high temperatures and pressures, which takes a lot of energy. Where are these people getting their methanol?
This kind of thing doesn't happen in USAA because USAA only serves military officers and their families, not enlisted men. It's legal discrimination because it's not on the basis of race, sex, religion, etc. Fortuneately, my Dad was an officer so now I get honest banking and car insurance for life.
These researchers at Caltech have built a fully immersive flight simulation chamber with displays updating at 200Hz. The entire chamber is mounted on a 3 axis gimbal to provide pitch, roll, and yaw. This gimbal can rotate at over 300rpm with angular accelerations of 20000deg/sec. Despite the impressive hardware, it fits in the corner of a small room. Unfortunately, in order to train on this equipment you must be a fly.
My university uses mostly solaris for the central servers, and they still have a lab of solaris 8 workstations. Nobody uses those, however, because most departments have their own labs, mostly using Dell/Linux. The CS department was using Redhat and FreeBSD for years, but they just switched to Mandrake when Redhat changed its license.
This technology will never go anywhere. I worked on a liquid nitrogen powered car at UNT, which is basically the same as this thing except the nitrogen can be stored more densely when it liquifies, at moderate pressures. Expanding the nitrogen requires a rack of heat exchangers on the roof. However, since all the energy is stored mechanically rather than chemically, the Joules/Kg is about 40x lower than than of gasoline. It's even less dense than batteries. About the only market for this technology would be indoors where exhaust fumes are not allowed. But an electric vehicle would do better.
Our car was a VW bug, had 9 hp, got 1/3 mpg in the summer, and once reached 30 mph.
If you're planning on doing any computerized analysis of images, a cheap webcam might be worthless. Most vision algorithms look at the laplacian of the image in order to achieve lighting invariance. However, most webcams compress images in ways that completely trash the laplacian, but aren't very noticeable to the human eye.
D-CAM is an uncompressed standard for digital cameras, and is perfect for machine vision applications. We've used Point Grey Dragonfly cameras with great success.
My roomate here at Caltech did DDR for 3 units of PE credit last fall as a self designed fitness program. 5 or 6 others did it with him. He would have continued in the next term, but he broke his back:( DDR just isn't the same anymore
Nope. CMU flipped last thursday while testing on their own, damaging a fair amount of equipment. But I saw them today, and they had done a remarkable job of repairing the damage.
As for the qualifications, I think this goes to show that 1 year isn't enough to build such an incredibly new machine.
Slashdot Mirror
On SSDs, the tables used for wear-leveling get fragmented over time. One trick that works with almost all SSD models is to do a sequential write of every logical block, _twice_. That will result in unfragmented tables. It might work on thumb drives too, but remember to do it twice. Try this:
dd if=/dev/zero of=/path/to/usb/drive
dd if=/dev/zero of=/path/to/usb/drive
Disclaimer: I work for an SSD company.
I am doing exactly what the OP wants to do. I've been living in my RV (29' 5th wheel trailer) for 6 months, and I'm typing this post over my satellite connection from the northern Cascade mountains in Washington. Here is what I have learned:
1) Satellite is the only way to go when you get out in the boonies. When we started this trip, I had an Openmoko phone as a backup ISP, but I dropped the data plan 2 months later because I almost never had connection.
2) Hughesnet is the only affordable satellite provider. Some other companies resell Hughesnet service. I use Motosat, which caters to the RV market. You will probably have to use a reseller, as Hughesnet's own TOS doesn't allow mobile use and they don't want you as their customer.
3) You can get an ordinary residential Hughesnet dish and mount it on a tripod, but aiming that dish is a royal PITA. www.maxwellsatellite.com sells dish, tripod, and pointing gear as a combo for IIRC $500. But it's still a PITA to point (the record holder from their user's group did it in 5 minutes), and vulnerable to theft. I wouldn't consider it an option if you are going to be moving frequently. A better setup is a roof mounted tracker, like what Motosat makes. Their motorized, and usually acquire the satellite in under 5 minutes with no help from the user. But you're going to have to pay: new systems cost $5k. I got mine used off eBay and installed it myself for $2k. Soldering Iron not required, but expect to cut and crimp a little cable, and of course you have to do the roof mounting. The hardest part was lifting the dish up onto the roof, because it's 80lbs with mount.
4) Contrary to what some other poster said, these dishes are NOT comparable size to TV dishes. They are larger, because they need to transmit info back to the bird. They start at 0.74m diameter. This means that pointing them is harder than pointing a TV dish, and they absolutely cannot be used while in motion.
5) Do not buy an RV with a rubber roof. Just don't.
6) Are you using solar power? I do, and it's worked out quite well. I could give you some tips if you want.
My recommendation would be Hughesnet with a motorized tracker, and a 3G phone if you need connection while moving on the highways. You can learn more about my experiences with the technomadic lifestyle at http://lauralan.livejournal.com/
Water vapor would be a powerful greenhouse gas, if there weren't already so much of it there. Basically, our atmosphere has so much water vapor, that every frequency of IR that can be absorbed by it is already fully absorbed. So more water vapor won't make a difference. CO2 and CH4, on the other hand, are potent greenhouse gasses because not only do they absorb IR, but they're pretty scarce our atmosphere.
Let's do the math, but starting from different angle. Really cheap electricity is $0.10/kWh, and the fuel station will probably charge a 30% markup at a minimum, for $0.13/kWh. For $3.00, if the air compressor is 100% efficient and there are no resistive losses involved with charging the tank, and you charge it at constant temperature you can store 23kWhr. In reality it would store less because the air would heat up as it compresses, then cool down after you leave the pump. The pressure would drop as it cools, so you'd be paying for pressure that you never get to use. The most fuel efficient cars today are hybrids that get 70mpg under very favorable conditions. Gasoline has 34.6MJ/liter (http://en.wikipedia.org/wiki/Gasoline), so if the Prius is 48% efficient (http://www.uwgb.edu/dutchs/EarthSC102Notes/102Ene rgy.htm) it will take 70mpg / 34.6MJ/l / 48% * 3.785gal /l * 1.6km / mile = 25.5km/MJ . With our cheap power, that comes out to 25.5km/MJ * 0.278 MJ/kWh / $0.13/kWh = 54.6 km/$ , or $5.49/300km . So expecting to travel 300km with only $3.00 worth of fuel would require you to invent a 100% efficient compressed air powertrain, get really cheap power, and double the efficiency (post-engine) of modern cars. Not bloody likely.
We can also calculate the pressure and maximum size of the fuel tank if we remember that PV=nRT and W = integral(P, dV). Solving for constant temperature charging gives W = nRT_initial - lnV |(V_initial - V_final) . Traveling 300km with the above figures requires storing 11.76MJ. I get 24.8m for the maximum tank size that would still be high enough pressure. But that's bigger than the car. A 50 gallon tank is probably about the biggest you could fit in that tiny car, and this would be only 0.187 cubic meter. Such a tiny tank could theoretically store 56MJ. If that is indeed their tank size, then the car might actually work with realistically efficient parts. But from Boyle's law the pressure would be 500atm!
The reason linux distros are so different, on PCs or on cell phones, is that open source apps don't need a standardized environment and linux is made to work with open source apps. If your application uses autoconf, it's pretty darn easy to port to any distro. But have you ever tried installing matlab, lexmark printer drivers, or games? Closed source software like that has arcane installers that only work on red hat and have to be reverse engineered for other distros. The people who want linux to "standardize" are the people who want to sell closed source apps. "Standardization" would hurt those who use only FOSS because it would greatly reduce choice in your distros. FOSS is the core function of linux (that's the GNU in GNU/Linux). Linux should not cripple itself to make room for non-free software.
I don't speak German and I don't know German law, but it seems to me that the crucial change behind this plan is that downloading will be criminalized. In the US only uploading (copying & distributing) is illegal. Making it a crime just to possess information has serious free speech ramifications. Does anyone know if downloading is illegal in Germany today?
You can use your smartphone to annoy telemarketers. Just write a program that analyzes the power per unit time of the conversation to detect pauses. When the telemarketer pauses, the program plays an interjection like "yeah" or "uh huh" or "I don't understand". When your phone rings and you answer it and hear a telemarketer, press the "spam" button and put the phone away, secure in the knowledge that your program will waste a minute or so of the spammer's time.
You miss one important difference between google and experian: Google is a tool to put public data into private hands; Experian puts (what should be) private data into public hands. Both are legal, but in a society with a right to privacy Experian wouldn't be. Our founding fathers didn't anticipate Experian, or they probably would've put a Privacy Amendment into the Bill of Rights. It's a damn shame they didn't.
Dude, learn the difference between temperature and heat. It takes an equal amount of heat to heat 1 gram of H2 to 1 billion degrees as it does to heat 10 grams of H2 to 100 million degrees (ignoring the effects of the plasma phase transistion; IANA(N/P)P ). His device operates on a very small scale. Very little H2 involved, means very little heat energy required. Also, it doesn't say that the copper electrodes ever get that hot. They wouldn't, because there isn't much gas involved, there isn't much time for heat transfer, and those magnetic fields ought to be designed to focus the plasma away from the electrodes. I'm not saying that this thing will work as well as Dr. Lerner says it will, but your criticisms are at least as bogus as his claims.
Step 1: grow algae
Step 2: refine into biodiesel
Step 3: Profit!
I always thought step 2 was the hard part, because it requires methanol (biodiesel is basically a methanol-fatty acid ester), and methanol is tough to make. It gets made by cracking petroleum catalytically at very high temperatures and pressures, which takes a lot of energy. Where are these people getting their methanol?
This kind of thing doesn't happen in USAA because USAA only serves military officers and their families, not enlisted men. It's legal discrimination because it's not on the basis of race, sex, religion, etc. Fortuneately, my Dad was an officer so now I get honest banking and car insurance for life.
You want to protest? Then do your slashdot best! http://www.live-shot.com/
These researchers at Caltech have built a fully immersive flight simulation chamber with displays updating at 200Hz. The entire chamber is mounted on a 3 axis gimbal to provide pitch, roll, and yaw. This gimbal can rotate at over 300rpm with angular accelerations of 20000deg/sec. Despite the impressive hardware, it fits in the corner of a small room. Unfortunately, in order to train on this equipment you must be a fly.
My university uses mostly solaris for the central servers, and they still have a lab of solaris 8 workstations. Nobody uses those, however, because most departments have their own labs, mostly using Dell/Linux. The CS department was using Redhat and FreeBSD for years, but they just switched to Mandrake when Redhat changed its license.
This technology will never go anywhere. I worked on a liquid nitrogen powered car at UNT, which is basically the same as this thing except the nitrogen can be stored more densely when it liquifies, at moderate pressures. Expanding the nitrogen requires a rack of heat exchangers on the roof. However, since all the energy is stored mechanically rather than chemically, the Joules/Kg is about 40x lower than than of gasoline. It's even less dense than batteries. About the only market for this technology would be indoors where exhaust fumes are not allowed. But an electric vehicle would do better.
Our car was a VW bug, had 9 hp, got 1/3 mpg in the summer, and once reached 30 mph.
I speak from experience when I say that it doesn't take an OS to make an MP3 player -- I built one out of an 80186 with hardware mpeg decoding.
If you're planning on doing any computerized analysis of images, a cheap webcam might be worthless. Most vision algorithms look at the laplacian of the image in order to achieve lighting invariance. However, most webcams compress images in ways that completely trash the laplacian, but aren't very noticeable to the human eye. D-CAM is an uncompressed standard for digital cameras, and is perfect for machine vision applications. We've used Point Grey Dragonfly cameras with great success.
And what internet bank is that? Don't hold out on us, throw us a bone!
Note that this refers to sept. 6, 2003, not 29 days ago.
http://globalsecurity.org/military/ops/oplan-5026. htm/
http://globalsecurity.org/military/ops/oplan-5027. htm/
preview next time
My roomate here at Caltech did DDR for 3 units of PE credit last fall as a self designed fitness program. 5 or 6 others did it with him. He would have continued in the next term, but he broke his back :( DDR just isn't the same anymore
Nope. CMU flipped last thursday while testing on their own, damaging a fair amount of equipment. But I saw them today, and they had done a remarkable job of repairing the damage. As for the qualifications, I think this goes to show that 1 year isn't enough to build such an incredibly new machine.
Turns up a result, and doesn't trigger the porn filter. Add "babes fuck breast" if you like.
1: I eat hot XXX grits for breakfast 2: My friends make fun of my southern roots 3: I am sad.