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Uber Pushing For Patent On Surge Pricing

bored_engineer Re:not original (188 comments)

If the patent officer recognize it as useless, they will reject the patent.

5 days ago
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Study: Red Light Cameras Don't Improve Safety

bored_engineer Re:Old news. (281 comments)

Until four years ago, I worked in Los Angeles as a traffic engineer. The ATSAC system is used on more than 4,000 intersections, is interconnected, and makes adjustments to signal timing either manually or automatically. There aren't cameras at all of the monitored intersections, but you don't need cameras to measure traffic volumes and speed, they're just an additional tool.

Further, the systems that use cameras for vehicle detection are falling out of favor. There are too many conditions, such as rain, snow, fog and bright sunshine that can befuddle the systems and cause them to fall back to pre-set timing rather than relying on vehicle detection. Where inductive loops aren't used, radar is proving to be more reliable than cameras.

Even where there's no interconnection, most intersections have controllers that are considerably more sophisticated than simple timers.

5 days ago
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Study: Red Light Cameras Don't Improve Safety

bored_engineer Re:Old news. (281 comments)

But consider cameras used not to give tickets but to adjust light timings in real time.

It's already being done. Los Angeles started in 1984 in anticipation of the Olympics, with system called ATSAC. There are several different types in use today.

about a week ago
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Study: Red Light Cameras Don't Improve Safety

bored_engineer Re:Study financed by (281 comments)

I posted something similar above. NCHRP Report 731 hews pretty closely to the recommendations in the ITE Traffic Engineer's handbook. I'll add that the MUTCD, section 4d.26 refers to that 3 second minimum as guidance, and uses "should," rather than "shall" or "will."

about a week ago
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Study: Red Light Cameras Don't Improve Safety

bored_engineer Re:Study financed by (281 comments)

Sorry. I didn't read the second paragraph of the summary, and only skimmed the Ars article. I still assert that it's not law, it's a recommendation.

about a week ago
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Study: Red Light Cameras Don't Improve Safety

bored_engineer Re:Study financed by (281 comments)

Three seconds is the minimum duration as per federal law.

What gave you that impression? Signal timing is determined by an equation, but may have some minimum defined by local or state law, or in a design manual.

At 25 MPH with no grade, depending on law or policy, it may be perfectly permissible to have a 2.8s interval, though it's common in practice to round that to a minimum 3s. Here's the equation from the 1999 ITE handbook:
Y=t + 1.467v/2(a+32g), where
t=perception-reaction time, typically assumed to be 1 s,
v=speed in MPH (ITE recommends using the 85th percentile speed, but many agencies use the posted speed.),
a=deceleration rate, assumed to be 10 ft/sec^2,
g=grade.
If you want to read more, NCHRP report 731details recommended guidelines, and provides some history for the recommendations.

about a week ago
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UK MP Says ISPs Must Take Responsibility For Movie Leaks, Sony Eyes North Korea

bored_engineer Re:I wonder who bought him (216 comments)

Thanks. Why wouldn't radar work? Mountainous roads?

about three weeks ago
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UK MP Says ISPs Must Take Responsibility For Movie Leaks, Sony Eyes North Korea

bored_engineer Re:I wonder who bought him (216 comments)

Ethanol, by itself, has an octane rating of about 129. The octane rating isn't about the energy content of the fuel, but rather its tendency to ignite under compression ("detonate") as compared to iso-octane.

Those tube-shaped sensors can probably measure a bit more than speed. I don't know what is used where you are, but I recently completed the design for a dozen automatic vehicle classification stations. They measure speed, count axles, and of course, count vehicles. I doubt that the sensors you're talking about are for speed enforcement: That's easily done with radar and photos.

about three weeks ago
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ISS's 3-D Printer Creates Its First Object In Space

bored_engineer Re:Coupon? (69 comments)

http://en.wikipedia.org/wiki/F...

In this context, they're talking about a test sample. Perhaps the summary should have been edited to say so in plainer English.

about a month ago
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ISS's 3-D Printer Creates Its First Object In Space

bored_engineer Re:Next step - Semiconductors (69 comments)

Don't you need to move the spool of abs (or whatever plastic they're using) up there? I don't think this is about the weight that travels up there, but rather the time to deliver parts there. If X plastic widget will get the primary air scrubber(s) working again right now, that vastly trumps relying on a secondary for six months.

about a month ago
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Multiple Manufacturers Push Hydrogen Fuel Cell Cars, But Can They Catch Tesla?

bored_engineer Re:It's The Parts Count (293 comments)

"What if I suddenly feel like driving from Florida to Alaska?"

How about Arizona to Fairbanks. Seventeen days for the trip is quite a long time, though. I've driven between LA and Fairbanks twice, and can do it in 7 days without pushing too hard.

about a month ago
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Rooftop Solar Could Reach Price Parity In the US By 2016

bored_engineer Re:My two cents... (516 comments)

I think it'd be fine for utilities to charge something nominal for the privilege of solar.

I couldn't agree more. Where I live, I pay a monthly fee simply to be connected to the grid, whether I use any electricity or not. I assume that if micro-generation becomes common that the co-op must increase this fee. I will happily pay an increased fee to have the night-time and winter generation that are impossible with solar.

Personally, if I could afford solar panels, I'd be interested in what uses it could provide during power outages combined with a battery backup for certain breakers/circuits (fridge, lights, and maybe one for TV watching).

A transfer switch, combined with a good inverter (or a pair, depending on your load) can provide this today. (The transfer switch is mandatory for any solar install, anyway, so as to keep utility workers safe.) In fact, this has been possible for at least 15 years. In fact, a good inverter can act as the charge controller for your batteries, as well as manage a back-up generator to keep the batteries charged during an extended outage. If you want a good system that provides backup power, I would talk to somebody about designing it for you, rather than trying to cobble it together yourself.

about a month ago
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X-Class Solar Flare Coming Friday

bored_engineer Re:which side of Earth? (145 comments)

There's a very nice graphic, so you needn't strain yourself by reading. You only need to scroll, and click twice. While the picture seems to paint a very precise picture, the article states that the timing is ambiguous, so it might not land so directly in North America.

about 4 months ago
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X-Class Solar Flare Coming Friday

bored_engineer Re:Just as long as it's not XK-class. (145 comments)

Bad news for me, though. I live at 65 degrees north latitude, and had a power outage for most of a week last winter in November. (That's fall for those of you who have more than two seasons.) There were so many trees in lines and transformers blown that they had to bring parts from outside, and crews from Anchorage. While the temperatures weren't yet brutal, (actually, they never really got there last winter) 0F in November is quite enough to freeze pipes.

Thankfully, I have a wood stove, a slightly abnormal interest in portable lights, and more portable cooking stoves than any one family can possible need. There's one cell tower close to my home, and I charged a large battery and my devices at work each day, so I didn't even lose internet access. I lost running water, but easily melted enough snow for water for drinking, washing and toilet-flushing. I also used snow to keep everything in the refrigerator cold, and moved everything in the freezer outside into a cooler. I was much happier than the neighbors 1/2 mile each way.

Unfortunately, we're facing an unseasonably warm September. I'm not sure what I'll do if power's out for several days right now. I can buy water and dry ice from town, but will the internet pipes freeze up? ;-)

about 4 months ago
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How the Outdated TI-84 Plus Still Holds a Monopoly On Classrooms

bored_engineer Re:TI calculators are not outdated, just overprice (359 comments)

In response to another comment, I took a look at the 50g, and at the Prime and very nearly bought the 50g right then. I noticed, though, that I can get a used 48gx for $200-$250. It's a hefty price difference, but there's zero learning curve. Maybe I'll think about it for another year or so. . .

about 4 months ago
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How the Outdated TI-84 Plus Still Holds a Monopoly On Classrooms

bored_engineer Re:RPN FTW (359 comments)

Take a look on Amazon for the HP50G for $87. It reviews well, and the top reviewer appreciates the feel of the keys. I bought an HP35S for the PE exam a few years ago, and keep it for a backup in case my 48GX dies, but I don't really like it. Unless it's directly on a desk surface*, it frequently misses the "enter" and the "+" keys. You can imagine, I'm sure, that missing any key can be a real pain in the ass. Also, the stack on the HP35S is frequently too small for my needs; doing simple statistical work on it sucks; it has very little unit conversion; and, memory available for programs is just too damn small.

I've been waiting, but you may have helped me make up my mind to buy the 50G, instead of trying to find a used 48GX

I also noticed that HP is making one that they call the "prime." It sells for $115, and I have no idea about the keys. The top reviewer on Amazon loves the thing to death, but mentions that "RPN Mode" needs more work. If "RPN Mode" needs more work, I'm not sure that it'll be all that useful for me.

*I tend to put my calculator on my engineering pad, or perhaps on a reference book while I'm doing calculations.

about 4 months ago
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How the Outdated TI-84 Plus Still Holds a Monopoly On Classrooms

bored_engineer Re:TI calculators are not outdated, just overprice (359 comments)

It hasn't been open-book since, at least, 2000. When I took it, I was given a small booklet with useful equations and a pencil. The only materials I was allowed to bring were my calculator and my coffee. (Maybe I had an eraser, too. When I took the PE exam, they wouldn't even let me have my own eraser.)

about 4 months ago
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How the Outdated TI-84 Plus Still Holds a Monopoly On Classrooms

bored_engineer Re:TI calculators are not outdated, just overprice (359 comments)

They disallowed calculators like the HP-48 beginning in 2000, the year I walked into the exam with an HP-48. Thankfully, the proctor allowed the calculators because NCEES had done a poor job of informing examinees. I doubt that there were more than a handful of students who had anything besides a graphing calculator, with the HP-48 being the clear majority. I'll be in bad shape when that calculator finally dies.

about 4 months ago
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Whole Organ Grown In Animal For First Time

bored_engineer Re:Sweet. (77 comments)

*shudder* This made me think of Repo Men.

about 4 months ago

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