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Comment Re:man 3 fsync (Score 2) 63

Normally, writes to disk can't be confirmed faster than one per full revolution of the platters. Thus, a 7200 RPM disk can not perform more than 7200 transactions a minute.

It can perform transactions at a much higher rate than that by using group commit, and any performance-sensitive system (including journaling file systems) will indeed use group commit. But the mean latency for any one commit does end up being limited to the time to perform half a disk rotation, and that's what non-volatile DIMMs are about - reduced I/O latency.

Comment Re:Why did these require so much power? (Score 1) 88

Because those battery tubes, to achieve their low filament-power consumption, used directly-heated cathodes (as you noted). If you think about this a bit further, you'll realize that this greatly limits the number of circuit topologies, because all of the cathodes in every tube must be connected together via the filament power supply. Imagine constructing logic gates where every transistor's emitter had to be directly connected to ground. Do-able, but limiting.

Comment Re:More articles like this please (Score 1) 551

For anyone whose interested, the Planet Money blog and podcast is a great place to start. Their reporting and research is done by actual economists rather than ideologues and talking heads

Planet Money is a joke. None of their correspondents are economists. David Kestenbaum is a journalist who happens to have a PhD in physics. Adam Davidson is not an economist; his background is journalism. Davidson clearly has a Milton Friedman bias in his economic reporting; just look at his blog posts on the subject of economic stimulus.

For a critical look at NPR (Nice Polite Republicans) check out the NPR Check blog.

Comment Re:toposhaba (Score 2, Insightful) 792

Don't we want to encourage more fuel-efficient road vehicles? Seems like upping the gas tax would be a good way to do that.

Perhaps once we're all driving electric vehicles we might then consider a per-mile tax. Until then, the incursion on civil liberties and privacy from vehicle tracking doesn't seem to be outweighed by the societal benefits.

It seems to me that these vehicle-tracking ideas are a clever political scam that combines avoidance of a politically-costly raising of the gas tax, corporate welfare for some well-connected companies, and a plausible-sounding policy-wonkish cover story.

Comment Re:Less Lethal... (Score 1) 334

That's a little unfair; you've no citations in your post :-)

However, the fact that batons leave marks (physical evidence) whereas tasers do not implies that police are less likely to inappropriately use batons than tasers, since the inappropriate use of batons results in evidence visible to a board of review.

It's clear from news reports that police are overusing Tasers by using them as torture devices in circumstances where, if they had instead beaten the subject with a baton, the evidence of physical injury would have resulted in the censure or firing of the police officer.

Comment Re:Less Lethal... (Score 1) 334

It seems that there are quite a few incidents wherein police officers have reached for their TASER rather than reaching for their deescalation skills. I don't think you can blame this on the tool though -- you have to blame it on the operator. These same personalities would probably have wielded the police baton in the same inappropriate manner.

The police baton is less likely to result in death.

Comment Use the text "How to Design Programs" (Score 1) 214

Use the textbook "How to design programs" by Matthias Felleisen, Robert Bruce Findler, Matthew Flatt and Shriram Krishnamurthi., It's available free on the web or hardcopy from MIT press. Unfortunately the HtDP web-site seems to be down today. Check out the wikipedia entry. It's been used in high schools. They have a summer seminar for teachers, too.

Comment Scheme and "How to design programs" (Score 1) 962

Use the text "How to design programs" and Scheme. It's been used in high schools, is quite approachable, and is easily motivated by connection to recurrence relations, which seem to be a theme in my 14 year old's math curriculum. The book is free on the web, and the programming environment is also free and supported on many popular platforms.

Comment Re:Girder and Panel!! (Score 1) 785

We used to call these "Kenner sets". The best was the "chemical plant" one, which had tanks, pipes, valves, and a pair of reservoirs with motorized pumps. You could build (simulated) oil refineries! The highway and skyscraper sets were pretty good, too. You could build huge suspension bridges with the sets, and they were pretty close to HO scale so you could integrate them into a train layout.

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