Developing one-off prototypes is easy compared to developing a refined vehicle that will meet consumer demands, all government regulations, can be manufactured efficiently and be built at a competitive price. If is was easy as you make it out to be, why is it that no one has done it yet? Plenty have: http://en.wikipedia.org/wiki/Category:Former_production_electric_vehicles
There is nothing new that needs inventing here. Only better batteries, which may have arrived.
Neither locomotives nor the tanks you mention use any type of electrical storage. Rather, the only reason for the the hybrid electric system in those vehicles is to replace what would otherwise be a very complicated ultra-high-torque transmission. That might be true, but it is also true that it can not be significantly more inefficient than the alternatives. Fuel cost is a major cost in operating a train, and inefficient engines would not be able to compete.
The loss from converting motion to electric and back again, is made up by being able to run the engine at optimal load and RPM.
You can also not ignore that all other (mechanical) transmissions have losses. There is no such thing as a lossless transmission.
It is trivial to make a bypass system that connects generator to motor directly. Perhabs that is even how it is done - the battery is charging as an extra load on the generator-motor connection.
A car like Tesla is not using tens of volts. IIRC it using something like 400V. Each cell might only be 2.5V, but even a kid knows how to connect cells in series to get any voltage.
People who aren't automotive engineers always trivialize the implementation and think it's a great idea. Actual vehicle engineers realize that in many ways a series hybrid is the worst of both worlds: more complicated than an EV and a gas car combined, less efficient than an EV for short-range driving (because of the extra weight), and less efficient than a parallel hybrid (or even a normal gas car!) on long trips. The so called series hybrid is very old tech. It used to be called diesel-electric and is what many locomotives use. If it was less efficient, it is curious how it came to be _the_ standard for diesel locomotives.
Yeah, I realize you said you wanted the generator to be removeable, but that's another fantasy of armchair engineers. Yes, it's possible to engineer your complicated system, but it will add unacceptable weight and cost. At least you didn't say you wanted a removeable (swappable) battery. Some not so armchair engineers at Renault decided to implement battery swapping. They have announced to make 500,000 cars with that system. What makes you qualified, to denounce what a real car company like Renault is doing?
"A British Wind Energy Association report gives an average generation cost of onshore wind power of around 3.2 pence per kilowatt hour (2005). Cost per unit of energy produced was estimated in 2006 to be comparable to the cost of new generating capacity in the United States for coal and natural gas: wind cost was estimated at $55.80 per MWh, coal at $53.10/MWh and natural gas at $52.50."
3.2 pence is 6.4 cents. So why build a plant with technology that can only do 17 cents with hope that it might scale down to 10 cents?
So you are saying java is stupid for having several implementations of the java.util.Map interface? They are all the same, since there is no seek time, right?
Of course there will be new file systems for zero-seek hardware, that will be optimized for this environment.
I think I have once had this happen to me. Since all I was buying was an ebook, I simply entered a random US address that I pulled from a website. This worked fine.
So in reality, they accepted non-US cards just fine. They did not accept non-US addresses - even for a download able item.
I have observed a few things about my european VISA card on american sites: All they are able to verify is the card number, expiry date and the 3 digit security number. I am able to enter completely random information for all other fields, including the name field (the one they always ask to be spelled exactly like on the card).
In fact, I often have to enter wrong information, as my address include non english characters, and many american websites are apparently still made by people that live in a 7 bit ASCII world.
"Those kinds of things are best done with pencil and paper." - Huh?! Why do you assume reading and writting is best done with stoneage methods?
Looks to me, this thing will be great making kids interrested in reading more. I can just see everybody learning to use wikipedia at a young age to look things up. We definitly did not have that opportunity when I was in school.
Sure, I could have gone to the library and looked something up. But having it instantly available is totally different.
It should also be a great cost saver if it can replace old fasioned school books. I am sure a kid wears out more than $100 worth of books during school.
This seems to be a recuring slashdot agenda - for how many years have we now been reading slashdot articles about how people do not like their phones to be anything but a phone?
The reality is that the phones will continue to become more powerful. Your phone WILL be able to play mp3 files and read emails. It probably already is able to do these things.
If you, like me, want it to be primary a phone, then buy one that is small and to your liking. And use it as a phone. Stop bitching that it also can be used as a email client, in an emergency.
Skype is a useful tool. That's all I've got to say about that.
No it is not. Not for our business, where I already provide everyone with a phone system employees can use to call anyone free of charge. As long as it is business related.
If the company needs to save money by using VoIP (which we actually already do), we will make the decision centrally. It is not a decision for every random employee.
If the purpose of installing Skype is to make non-business related calls, then it is quite obvious why companies would like to prevent that.
You can say the same thing about the parent comment about java memory management. The J2ME for mobilephones does indead free the memory. Funny how java for embedded systems uses the same strategy eh? J2ME works with very little memory. A Nokia 3410 only has 64 KB memory for the java games.
The parent post was obviously talking about ordinary client applications running on PC under either Windows, Linux, Mac or something simelar.
On such a system, malloc cannot map directly to the OS API, because the OS will only allocate full pages at a time. So if you want 40 bytes of memory, the OS would give you 1 KB (or whatever the page size is).
This also means that if you allocate 2x40 bytes, then free the first 40 bytes block, malloc can not free the page. It is simply not possible, since it would have to free the whole page.
Some J2ME implementations can defragment the memory in this situation, to be able to release memory back to the OS. That is impossible with a C program, where direct pointers to memory is allowed.
For large blocks you can of course go directly to the OS.
You realise that the C malloc/free calls are just the same right? It never releases memory back to the OS.
The only difference in this regard, is that java might alloc extra memory from the OS, when it could have run the garbage collector and reused some memory instead.
Very few programs actually ever release memory back to the OS.
Does this thing come with a stereo PAL tuner? The spec sheets does not say, and neither does it say anything about text tv support, which is usually a big warning about a cheap mono tuner.
Signal strength alone is useless to triangulate. I did not go farther away just because I moved behind a wall.
But you could use timing instead. You could probably do that with any wifi card that allows you to "snoop" the airwaves.
The problem is of course how to get a timer that precise. The signal moves with a speed of about 3*10^8 m/s. To locate the sender within 3 meters, you need rougly a 10 ns timer. I don't think you could do that in software on an ordinary computer.
I live in denmark and recently we had a blackout that lasted maybe 10 hours.
While I was unable to make any phone calls, I could get on the internet with GPRS and surf to our server with my laptop for as long as the laptop batteries lasted.
The server is hosted in a colo datacenter which was also in the middle of the affected area. We run a mud on the server, and most of the players are from USA. They never discovered the blackout as the datacenter went on emergency diesel backup and apparently knew to make business with backbone providers that also knew their stuff.
So to the people saying that internet can only route around blackout areas but not _through_ them, this is not true. Seems at least here in denmark all the infrastructure on the backbones got backup power and just keeps working when everyone else is busy lighting candles.
All their books are DRM free and available in several different formats, including HTML (which obviously can't be DRM'ed).
I bought lots of ebooks there primary because it is so easy and I get the book instantly. I wont touch any ebook that has DRM as those always try to limit the number of devices I can read them on. Today I am reading those books on my iPAQ PDA, but in a year I have most likely retired that device for something better.
Contrary to what others seem to be saying here, ebooks really works for me. I almost completely stopped reading ordinary books, always prefering to use the light ipaq over a heavy real book. The display is clear, bright and does not strain my eyes. The battery lasts about 10 hours when reading. The only times where the battery live is a problem is when I am home, and there I just hook it up to power when it runs out.
It is not perfect, but it is more than good enough. At least for fiction reading anyway - I might not want to use it for a science text book, or any other book with tables, pictures and the like. Some of my ebooks contain maps, which are completely unreadable on the ipaq (but you can read them on the computer of course).
A few points. While it is true that an OS could provide most of the security mechanism that the JVM implements, I know of no such OS.
Can you configure MS Windows (any version) so that you will trust my.exe file not to do something very bad with your computer? If you think you can, you are a fool. But you can safely run my applet in your web browser.
The ability of Python (and probably Dylan - I don't know it) to call any function on any object comes at a price. You will first discover your errors at runtime instead of compile time. You can also do the same thing in java using the reflection API if you really must.
QT is not a standard C(++) library. To make C programs portable you need extra tools, which are not always free. As result most C programs written for the windows platfrom are not portable (even if yours might be). As you said, some of the power of java comes from its immense bundled library which happens to include a portable window toolkit.
I just saw an ad for a device named "United DVD HDV4080". This is supposely a DVD player with a 40 GB harddisk so it can record TV shows and do the live timeshifting thing etc.
Do anyone know this device, and can tell if it is any good or how it compares to TiVo or Replay TV? Can you upgrade the harddisk or somehow get the recorded shows out of it for long time storage?
Slashdot Mirror
How could it lose data? Flash has unlimited read cycles. It is the erase cycle that makes the cell fail.
So yes, it is true that flash devices do not lose data from write wear. Not that you will be able to trigger that condition with the new devices.
This is Irans second try, and it was approximately as successful as the second try of Space X.
Meaning, the first stage worked, the second stage kinda worked but in the end failed.
Now, if their third attempt works out, they did it better than Space X. But we don't know that yet.
I am still betting on Space X as having the better rocket.
There is nothing new that needs inventing here. Only better batteries, which may have arrived.
The loss from converting motion to electric and back again, is made up by being able to run the engine at optimal load and RPM.
You can also not ignore that all other (mechanical) transmissions have losses. There is no such thing as a lossless transmission.
It is trivial to make a bypass system that connects generator to motor directly. Perhabs that is even how it is done - the battery is charging as an extra load on the generator-motor connection.
A car like Tesla is not using tens of volts. IIRC it using something like 400V. Each cell might only be 2.5V, but even a kid knows how to connect cells in series to get any voltage.
They should simply build this thing like a normal elevator with a counter weight going down while the payload goes up...
Let me quote http://en.wikipedia.org/wiki/Wind_power:
"A British Wind Energy Association report gives an average generation cost of onshore wind power of around 3.2 pence per kilowatt hour (2005). Cost per unit of energy produced was estimated in 2006 to be comparable to the cost of new generating capacity in the United States for coal and natural gas: wind cost was estimated at $55.80 per MWh, coal at $53.10/MWh and natural gas at $52.50."
3.2 pence is 6.4 cents. So why build a plant with technology that can only do 17 cents with hope that it might scale down to 10 cents?
Many UAVs do not carry weapons at all.
All they need is the ability to observe the enemy and transmit the position to the artillery canons.
A video link and a GPS receiver is sufficient for the UAV to be used as a weapon system.
So you are saying java is stupid for having several implementations of the java.util.Map interface? They are all the same, since there is no seek time, right?
Of course there will be new file systems for zero-seek hardware, that will be optimized for this environment.
It should be relatively inexpensive to upgrade the 8 miles battery to something better.
This car already has the charger and everything else needed, so I expect easy to install battery kits to appear shortly.
If they could just double the all electric range, it would be enough for my daily commute.
Maybe you should be entitled to a jury of peers. Even in tech cases. Meaning a jury of engineers and not a jury of joe stupid.
I think I have once had this happen to me. Since all I was buying was an ebook, I simply entered a random US address that I pulled from a website. This worked fine.
So in reality, they accepted non-US cards just fine. They did not accept non-US addresses - even for a download able item.
I have observed a few things about my european VISA card on american sites: All they are able to verify is the card number, expiry date and the 3 digit security number. I am able to enter completely random information for all other fields, including the name field (the one they always ask to be spelled exactly like on the card).
In fact, I often have to enter wrong information, as my address include non english characters, and many american websites are apparently still made by people that live in a 7 bit ASCII world.
"Those kinds of things are best done with pencil and paper." - Huh?! Why do you assume reading and writting is best done with stoneage methods?
Looks to me, this thing will be great making kids interrested in reading more. I can just see everybody learning to use wikipedia at a young age to look things up. We definitly did not have that opportunity when I was in school.
Sure, I could have gone to the library and looked something up. But having it instantly available is totally different.
It should also be a great cost saver if it can replace old fasioned school books. I am sure a kid wears out more than $100 worth of books during school.
This seems to be a recuring slashdot agenda - for how many years have we now been reading slashdot articles about how people do not like their phones to be anything but a phone?
The reality is that the phones will continue to become more powerful. Your phone WILL be able to play mp3 files and read emails. It probably already is able to do these things.
If you, like me, want it to be primary a phone, then buy one that is small and to your liking. And use it as a phone. Stop bitching that it also can be used as a email client, in an emergency.
Skype is a useful tool. That's all I've got to say about that.
No it is not. Not for our business, where I already provide everyone with a phone system employees can use to call anyone free of charge. As long as it is business related.
If the company needs to save money by using VoIP (which we actually already do), we will make the decision centrally. It is not a decision for every random employee.
If the purpose of installing Skype is to make non-business related calls, then it is quite obvious why companies would like to prevent that.
You can say the same thing about the parent comment about java memory management. The J2ME for mobilephones does indead free the memory. Funny how java for embedded systems uses the same strategy eh? J2ME works with very little memory. A Nokia 3410 only has 64 KB memory for the java games.
The parent post was obviously talking about ordinary client applications running on PC under either Windows, Linux, Mac or something simelar.
On such a system, malloc cannot map directly to the OS API, because the OS will only allocate full pages at a time. So if you want 40 bytes of memory, the OS would give you 1 KB (or whatever the page size is).
This also means that if you allocate 2x40 bytes, then free the first 40 bytes block, malloc can not free the page. It is simply not possible, since it would have to free the whole page.
Some J2ME implementations can defragment the memory in this situation, to be able to release memory back to the OS. That is impossible with a C program, where direct pointers to memory is allowed.
For large blocks you can of course go directly to the OS.
You realise that the C malloc/free calls are just the same right? It never releases memory back to the OS.
The only difference in this regard, is that java might alloc extra memory from the OS, when it could have run the garbage collector and reused some memory instead.
Very few programs actually ever release memory back to the OS.
Thanks that sounds great. How about PDC support then? That would be the last missing piece to be able to anything a good video and TV will do.
Does this thing come with a stereo PAL tuner? The spec sheets does not say, and neither does it say anything about text tv support, which is usually a big warning about a cheap mono tuner.
Signal strength alone is useless to triangulate. I did not go farther away just because I moved behind a wall.
But you could use timing instead. You could probably do that with any wifi card that allows you to "snoop" the airwaves.
The problem is of course how to get a timer that precise. The signal moves with a speed of about 3*10^8 m/s. To locate the sender within 3 meters, you need rougly a 10 ns timer. I don't think you could do that in software on an ordinary computer.
I live in denmark and recently we had a blackout that lasted maybe 10 hours.
While I was unable to make any phone calls, I could get on the internet with GPRS and surf to our server with my laptop for as long as the laptop batteries lasted.
The server is hosted in a colo datacenter which was also in the middle of the affected area. We run a mud on the server, and most of the players are from USA. They never discovered the blackout as the datacenter went on emergency diesel backup and apparently knew to make business with backbone providers that also knew their stuff.
So to the people saying that internet can only route around blackout areas but not _through_ them, this is not true. Seems at least here in denmark all the infrastructure on the backbones got backup power and just keeps working when everyone else is busy lighting candles.
If you like to read scifi or fantasy, one publisher already did all this.
Go here and check Baens webscription: http://webscription.net/
Or check their free library where you can read ebooks for FREE: http://www.baen.com/library/
All their books are DRM free and available in several different formats, including HTML (which obviously can't be DRM'ed).
I bought lots of ebooks there primary because it is so easy and I get the book instantly. I wont touch any ebook that has DRM as those always try to limit the number of devices I can read them on. Today I am reading those books on my iPAQ PDA, but in a year I have most likely retired that device for something better.
Contrary to what others seem to be saying here, ebooks really works for me. I almost completely stopped reading ordinary books, always prefering to use the light ipaq over a heavy real book. The display is clear, bright and does not strain my eyes. The battery lasts about 10 hours when reading. The only times where the battery live is a problem is when I am home, and there I just hook it up to power when it runs out.
It is not perfect, but it is more than good enough. At least for fiction reading anyway - I might not want to use it for a science text book, or any other book with tables, pictures and the like. Some of my ebooks contain maps, which are completely unreadable on the ipaq (but you can read them on the computer of course).
A few points. While it is true that an OS could provide most of the security mechanism that the JVM implements, I know of no such OS.
.exe file not to do something very bad with your computer? If you think you can, you are a fool. But you can safely run my applet in your web browser.
Can you configure MS Windows (any version) so that you will trust my
The ability of Python (and probably Dylan - I don't know it) to call any function on any object comes at a price. You will first discover your errors at runtime instead of compile time. You can also do the same thing in java using the reflection API if you really must.
QT is not a standard C(++) library. To make C programs portable you need extra tools, which are not always free. As result most C programs written for the windows platfrom are not portable (even if yours might be). As you said, some of the power of java comes from its immense bundled library which happens to include a portable window toolkit.
I just saw an ad for a device named "United DVD HDV4080". This is supposely a DVD player with a 40 GB harddisk so it can record TV shows and do the live timeshifting thing etc.
Do anyone know this device, and can tell if it is any good or how it compares to TiVo or Replay TV? Can you upgrade the harddisk or somehow get the recorded shows out of it for long time storage?