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We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).


Comment: Average speed cameras (Score 1) 483

by attonitus (#33319162) Attached to: Building a Traffic Radar System To Catch Reckless Drivers?
In the UK, reduced speed limits due to road-works on motorways are often policed using average speed cameras. These use number-plate recognition to identify cars as they pass cameras at two or more points, then calculate the average speed based on the distance between the points. The advantage of this as a home-brew solution is that you could build it with off-the-shelf equipment - no radar units needed. There's also no need to paint lines on the road or to calibrate a radar unit. It's also possibly more effective - there's no point slowing down just for the trap and then accelerating away again and it's passive, so radar detectors don't work. You'd need some license-plate recognition software, but I imagine there are free or cheap solutions available for that now. You'd need to ensure that your jurisdiction allowed you to photograph cars on a public road and store details of their number plates and you'd need to find a way to convince a court of the fidelity of the time-stamps on the photos (maybe have an OTS unprogrammable GPS unit sitting in view of the camera?).

Comment: Re:Um... shouldn't traffic lights come first? (Score 2, Interesting) 483

by attonitus (#33318960) Attached to: Building a Traffic Radar System To Catch Reckless Drivers?
Catching speeders imposes no new restrictions - it's just about enforcing the rules that are already in place. So presumably it requires much less effort from the politicians / authorities, which makes it a more achievable objective for this guy, who's just a private citizen.

Comment: Re:escalators too (Score 1) 698

by attonitus (#32832026) Attached to: Should Cities Install Moving Sidewalks?

Speaking of stairs and escalators, England really needs to catch up on this one. When I was riding the train there I kept having little old ladies ask me to carry their luggage for them up the stairs. I can't imagine what wheelchaired people do.

They have to plan their journeys around accessible stations, just like in the US. Incidentally, the "Stand on the right" notices all over escalators on the underground are supposed to (and generally do) achieve exactly the the effect that you describe. Oh, and you should probably have offered to help the old ladies before you were asked ;-).

Comment: OS X / Linux (Score 1) 434

by attonitus (#32304598) Attached to: Most Useful OS For High-School Science Education?
I'm a maths researcher. At my previous and current institution there's a mix of Windows, OS X and Linux. The people doing more serious coding tend to be on OS X or Linux - often both. IMANPE (In my admittedly narrow personal experience), I have never come across any research level codes that are Windows-only and I often use libraries that assume some kind of Make-style UNIX build environment.

Comment: Re:Unexplained Achievement "The Maker"? (Score 1) 1582

by attonitus (#27416693) Attached to: Slashdot Launches User Achievements
Yes you could, it's a tautology, not a contradiction. If I have all the other achievements and Slashdot gives me this one, then that's fine, I have the achievement, and hence I have the right to the achievement.

More problematic would be an achievement for having achieved nothing. That's when Bertrand Russell would come knocking.


+ - gcc says -10==10-> 6

Submitted by Anonymous Coward
An anonymous reader writes "A bug in gcc causes it to think -10*abs(x) and 10*abs(x) have the same value. Just compile the following small program:

int main( void )
    int i=2;
    if( -10*abs (i-1) == 10*abs(i-1) )
        printf ("OMG,-10==10 in linux!\n");
        printf ("nothing special here\n") ;
    return 0 ;

Link to Original Source

"You know, we've won awards for this crap." -- David Letterman