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Comment: Re:Regenerative breaking? (Score 1) 144

by SlashWombat (#29948164) Attached to: Appeal For Commuter GPS Logs To Aid Electric Cars

The problem is dumping that much power into a battery quickly.

I don't think that is a problem, most batteries that are not fully charged can withstand huge dumps of energy for short periods. In fact, the current produced during braking is probably less than that required during acceleration. The general problem is that the voltage coming from the electric motor is equal to (best case), or below the voltage of the batteries. So the voltage needs to be boosted above that of the battery before any regenerative charging takes place. Thus, taking significant extra electronics to do this.

Idle

"2012" a Miscalculation; Actual Calendar Ends 2220 600

Posted by samzenpus
from the lost-in-translation dept.
boombaard writes "News is spreading quickly here that scientists writing in a popular science periodical (Dutch) have debunked the 2012 date (google translation linked) featuring so prominently in doomsday predictions/speculation across the web. On 2012-12-21, the sun will appear where you would normally be able to see the 'galactic equator' of the Milky Way; an occurrence deemed special because it happens 'only' once every 25.800 years, on the winter solstice. However, even if you ignore the fact that there is no actual galactic equator, just an observed one, and that the visual effect is pretty much the same for an entire decade surrounding that date, there are major problems with the way the Maya Calendar is being read by doomsday prophets." I wonder what Amazon's return policy on a box full of 3 doomsday wolves shirts is?

Comment: Re:well now (Score 1) 219

by SlashWombat (#29854915) Attached to: Sparc Sends SparkFun Electronics C&D Letter
Spark in electronics predates Sparc in computers by several decades. (Even a century perhaps?) Radio transmitters were originally powered by a spark! See Hertz's original apparatus for the earliest example! Perhaps they should rename themselves to FarkFun, then Sparc's lawyers wouldn't even try to sue for fear of being completely ridiculed by the general public!

Comment: Re:Let me guess... (Score 4, Interesting) 104

by SlashWombat (#29776215) Attached to: Canadian Copyright Lobby Fights Anti-Spyware Legislation
I would have to agree with this, except that most copyright ends up being owned by the very large corporations you suggest are the current demons. To make copyright fair again, I would suggest that copyright not be transferable from the original authors. Indeed, this should be back dated 100 years to totally undo the shit that these companies have perpetrated on the global population. I would also suggest that the copyright period be reduced to something more reasonable, say 50 years ... If you haven't made money/reputation in that period of time, you never will!

Comment: Re:How about Gauss in 1805 (Score 1) 267

by SlashWombat (#29765587) Attached to: Wi-Fi Patent Victory Earns CSIRO $200 Million
Okay, in reply. Yes, the FFT has been described several times over the last few centuries, but it never really achieved any recognition until Cooley & Tukey described it. (One of these authors actually seemed surprised at the recognition he gained from the FFT ...)As for hardware implementations of the FFT. The CSIRO FFT chip predates the WiFi by a significant amount of time. Probably not the first implementation in hardware, but undoubtedly one of the first ten. The FFT requires significant amounts of logic to implement, and certainly early FPGA's were did not have sufficient resources to implement it. Having grown up with much of this technology evolving as I worked with it, I don't have the impression that chips are (or were) as fast as some people here seem to think. You must remember that the state of the art in 1975 was the 8080 cpu ... roughly 10,000 gates. A decent FFT requires much more than that (and memory chips as well!) Whilst DSP's of the 80's (any computer chip actually) could do semi decent jobs in the FFT arena, they certainly couldn't do several megabytes a second, even for a 256 bin FFT. (Also, back in the late 80's / early 90's, DSP's cost an arm and a leg -- making them somewhat prohibitive for many applications!)

Yes, the technique is OFDM ... principally so that the symbol timing can be made relatively long, thus simplifying/improving the data recovery in the presence of echo's. (Simply integrating the data over time makes this an easy process to implement.) Digital communications really didn't begin to evolve until several technologies had evolved, not just FFT's, but also analog to digital converters that could operate successfully at multi MHz clock rates. In 1980, I purchased several 6 bit flash converters that would work at up to 30 MHz (results were pretty horrible by todays standards ...) --- these cost me $100 each. Now you can easily get a 100 MHz 14 bit converter for a few dollars, and the results are spectacular. (OFDM requires at least two Analogue to digital converters on the Receive side ... plus high speed sine/cos generators to provide the mixers before the ADC's {to generate the real and imaginary components feeding the FFT ...}

So, what seems easy now (perhaps even obvious) was certainly ground breaking stuff only 20 or so years ago!

Comment: Re:can you explain? (Score 3, Interesting) 267

by SlashWombat (#29754283) Attached to: Wi-Fi Patent Victory Earns CSIRO $200 Million
At the time of its invention, it was not a simple application of known techniques. Now many digital transmission schemes use similar techniques. So yes, they deserve some credit for the invention. (The reason it wasn't mainstream before this is due to them using a CSIRO FFT hardware chip, something that wasn't really around until chip manufacturers/designers achieved the miniaturization necessary for its implementation. The FFT wasn't even described as a mathematical process until early 1960.

Comment: Re:It's 1996 again? (Score 1) 300

by SlashWombat (#29689901) Attached to: FCC Chairman Warns of Wireless Spectrum Gap
Actually, thats only true to a small extent ...Spread Spectrum allows many transmissions on the same frequency with only a small degradation when multiple sites are active (but using different "golden keys"). The penalty is slightly more noise, but hardly an issue. So there are ways to use the spectrum (much) more efficiently!

Comment: Re:indeed (Score 1) 130

by SlashWombat (#29633487) Attached to: SFLC Tells SCOTUS, "Software Patents Are Unjust"
One of the problems I see is where software overlaps hardware ... For instance, JPEG (or for that matter, MPEG) Are covered by patents. Although the engines can be described in Actual hardware, they are generally described in software. As computer hardware gets faster, more machines will be described in software before they are implemented in hardware, yet, as I see it, these inventions are worthy of protection via the patent system. (However ... The JPEG patents are held by several different people/organisations, as the patents are all on seperate pieces of the actual algorithm ... So perhaps patents should not be allowed for such narrow specialities. I also wonder about the "novelty' of some of these patents ... I would argue that many of them would have been invented by most people active in a particular field ... Not requiring genius to produce the invention.)

Comment: Re:Well (Score 1) 238

by SlashWombat (#29613745) Attached to: GE Developing 1Tb Hologram Disc Readable By a Modified Blu-ray Drive
If you expect Bluray to last 70 years, you are dreaming. CD technology is now on its last legs, and that is roughly only 30 years. DVD will die as soon as Bluray is cheap enough for the average punter. Expect blue-rays successor will last as long as blue-ray has! Technology is still on the exponential curve, therefore the "upgrades" will only come faster than ever before.

Nothing is impossible for the man who doesn't have to do it himself. -- A.H. Weiler

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