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Comment: Re:Why 'united kingdom' tagged british phone booth (Score 1) 520

by mattj452 (#35054906) Attached to: Kilogram Gets Controversial; Why Not Split the Difference?

as the article's image/icon ? kilogram has nothing to do with united states, unfortunately.

Well it does. One Pound (the U.S weight that is, not the British coinage) is defined as 453.59237 grams. So your definition relies very much on the piece of platinum diluting away in a French vault.

Comment: Re:BANDWIDTH FAIL (Score 1) 82

by mattj452 (#33860570) Attached to: Profs Bring TV Spectrum Free Wi-Fi To Houston Area
Whitespace technology already exist. Although people surely want to legislate slightly differently, it would be entirely possible to use the existing 802.11 stack to achieve this. 802.11G uses 20MHz per channel, and there are half rate and quarter rate specifications (using 10MHz and 5MHz). In addition, 802.11h brough you a dynamic channel switching mechanism. It is technically used to avoid radar signals on the 5GHz band, so some additions to the standards on when to change (if change is necessary!) in the lower bands. For your comment regarding DSL: Sure they can, but people want to be more mobile nowadays, without being bound to their home. I'm not saying 802.11 is the best standard for this, all I'm saying is 802.11 would work.

Comment: Re:What can they hope for (Score 2, Informative) 105

by mattj452 (#33518326) Attached to: DARPA Wants Extreme Wireless Interference Buster
I'd imagine that not only will they look at those techniques (FEC, spread spectrum etc), but also techniques related to intelligent channel switching when a channel is jammed. Also, there are other methods than noise to interfere with the reception. For example, sending out false signals, repeated signals etc which also needs to be considered.

Comment: Re:I call BS.kg (Score 1) 272

by mattj452 (#33424224) Attached to: EPA Proposes Grading System For Car Fuel Economy

'Greenhouse gas emmisions'? Does this include the source power generation? Of course not, because some regions use wind/solar/nuclear, which have a vastly different greenhouse gas emmsiions then others.

Not only different per region, but it would also differ in time, especially in regions where it gets cold in the winter. A greenhouse friendly energy source can be happily used during summer, but once the chilly winds starts coming about, people will turn up their heating and suddenly the fine wind farm up the road can't handle it. The energy will be upped by the upstate coal power plant. The margin energy suppliers (i.e. on-demand suppliers) are always coal, oil or gas since no other source can increase its capacity. The result is that your nice Prius will run on clean energy in the summer, but a mixture of green and not-so-green in the Winter. Hence, not so easy to rate as the others. In the ratings defence I do like the system but if it is going to have any effect, there is a need for either a carrot or a whip. In the UK, the vehicle tax is based on CO2 emissions, which I think is a decent system although far from perfect since hybrid cars are rated on their 'best' fuel even though it is up to the driver to decide which fuel to use.

Comment: First? (Score 5, Interesting) 115

by mattj452 (#33410522) Attached to: Brazil Using Smartphones For Planning the Future
The Nordic countries (Sweden, Norway, Denmark, Finland in this context) have all abolished the manual census counting years ago. In Sweden, the last census survey was made in 1990. Since then, an automatic system has been in place to which you report whenever you move, get married, have kids etc (well, I think the hospital is reporting children). Formally, this has to be made on paper so it is technically not a fully digital system. However, since the introduction of E-ID's a few years back, it has been possible to do this online, beating Brazil with at least 4 years.

Comment: Re:Also (Score 1) 277

by mattj452 (#32688918) Attached to: Tracking Down a Single-Bit RAM Error
The problem he is experiencing is most likely a hard drive problem. 1. He is consistently experiencing it. A restart of the computer would most likely having 'expr' end up in a different location in RAM memory, so the error should not be consistent. 2. There is nothing here indicating a single bit error. He sees that he suddenly tries to read from an invalid location. The problem can be either that the read address has been corrupted, or the instruction itself (i.e. it shouldn't have been a read). Also, there is nothing saying that this is the only place the fault occurs, only that this is the first place it occurs. The rest of the program may very well be corrupt, as can the entire sector.

Comment: Re:it's not a base station (Score 1) 204

by mattj452 (#31868418) Attached to: Israel Blocks iPad Imports, Citing Wi-Fi Transmission Regulations
There is nothing stopping you from creating an ad-hoc network in the 5 GHz band. Also, in the 5GHz band, 802.11h is implemented as well. One of the requirements is to randomly select the channel to be used (when you create the network that is). Third, the IPAD hasn't been WiFi certified yet. Check WiFi Alliances website: http://www.wi-fi.org/search_products.php?search=1&advanced=1&lang=en&filter_company_id=5&filter_category_id=&filter_subcategory=&filter_cid=&date_from=&date_to=&x=47&y=9 Now, not having it certified doesn't mean that it is automatically banned, but it sure doesn't prove that the device is legal in Israel or Europe (where it is not yet being sold).

Comment: There is already a technical solution for this (Score 1) 179

by mattj452 (#29259079) Attached to: Wind Farms Can Interfere With Doppler Radar
Doppler radars in reasonably modern military systems can find hovering helicopters (doppler radars normally filters stationary objects) by detecting the rotating blades. Although weather radars operate in a different frequency range, the problem they have is effectively the same or actually the opposite - they want to mask the "helicopters".

Comment: lim-0 (Score 3, Insightful) 495

by mattj452 (#28629333) Attached to: How Heavy Is a Petabyte?
Since data storage is just one case of transmission channel (just sending it through time, not space) you can store the 6 Petabytes in a transmission. All you need to do is place one sender here, and one eh, let's say at the end of the Universe. As long as the data is being transmitted, it doesn't really weight anything. Yes silly question will get a silly answer :)

I am not now, nor have I ever been, a member of the demigodic party. -- Dennis Ritchie

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