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Comment: Of course you use force control to run fast. (Score 5, Insightful) 33

by Animats (#47915427) Attached to: MIT's Cheetah Robot Runs Untethered

That article is written as if that crowd invented running using force control. Of course you use force control. Everybody in the field knows that by now. I patented that 20 years ago. The Scout II robot at McGill, developed by Prof. Martin Buehler, used that approach. Buehler went on to become the designer of BigDog, but never got much public credit for it and quit to work for iRobot.

The key to legged running in non-trivial situations is careful management of ground traction. Traction is first priority, then balance, then foot placement. Historically, everybody worried about foot placement first, but that turns out to be backwards. As soon as you get off flat surfaces with good traction, traction control dominates.

The next unsolved problem in that area is not going fast. It's starting, stopping, and turning fast. Most of the legged robots accelerate very slowly, and don't make abrupt high-speed turns. Big Dog starts by trotting in place, then extending the gait out. Starting fast, stopping fast, and turning fast are all facets of the same problem. You have to take one stride using completely different control algorithms than you use for normal locomotion. That's all I'm going to say about this for now.

Comment: Clueless (Score 1) 52

by Animats (#47911665) Attached to: New Data Center Protects Against Solar Storm and Nuclear EMPs

This keeps coming up. The effects of an electromagnetic pulse and a solar storm are completely different. EMP is a big RF pulse with a risetime in the nanoseconds. This is a risk to input transistors connected to external wiring. Twisted pair, coax, and small mobile devices are relatively immune. Fiber optics are totally immune.

Solar storms induce DC voltages across long distances of conductive landscape. This is a risk only to transformers with grounded center taps connected to long transmission lines.

Here are the PJM power grid emergency procedures for geomagnetic events. They had to be implemented for a day two years ago. Almost nobody outside of power grid operators noticed.

Comment: Re:911 was down for us Friday night (Score 1) 559

I'm not sure why this is really an argument to be getting into. I'm going to throw the blame on Apple for this one for not using a dedicated swap partition.

It's hard to use up too much space for swap to work, when the space set aside for swap is literally impossible to use for other purposes.

Comment: Re:911 was down for us Friday night (Score 1) 559

The point is that you're dangerously toeing the line. Running out of disk space doesn't cause very graceful failures. Even a 5% "buffer" of free space is enough. I realize these are client machines and not servers, but still. You don't need pagerduty or whatever waking your ass up to deal with it, but you should be dealing with it instead of believing it to be a non-problem.

Comment: Have they Denied? (Score 2, Interesting) 187

NSA officials were unable to find any evidence Snowden ever had.

This is essentially the "I do not recall" equivalent of paperwork investigations.

The essential question here is whether the NSA can conclusively deny that Snowden never raised concerns at the agency. Since if he did raise concerns, he probably would have raised them to people personally, a document search is not nessesarily going to uncover whether he did.

What will uncover this conclusively is a simple interview of NSA and affiliate company employees and especially supervisors who worked with Snowden. But since such a set of interviews would either a) reveal that he did raise concerns, b) involve people having to sign their names to untruths, or most unlikely c) reveal he really raised nothing, then I think it's easier for the NSA to just pretend that a half-assed email server word search constitutes an appropriate investigation.

Comment: Only Apple can't make sapphire work. (Score 0) 199

by Animats (#47903731) Attached to: Sapphire Glass Didn't Pass iPhone Drop Test According to Reports

Everybody who gets an iPhone immediately puts it into a rugged, generally rubberized, case.

That's pathetic. All that effort to make a super-thin device, and you have to put it another case to protect it. Nokia would laugh.

Get a non-toy phone.

It's amusing that Apple can't get sapphire-coated glass to work. Sapphire glass for checkout scanners is a standard product. Every Home Depot checkout scanner has sapphire-coated glass. People slide metal tools across those for years without damage.

Comment: Re:hopeful (Score 0) 45

by X0563511 (#47903667) Attached to: KDevelop 4.7.0 Released

Apparently you missed 95% of my sentence. Here it is, again.

I'm hopeful the next era you let us turn off that fucking cashew without jumping through 30 flaming hoops.

without jumping through 30 flaming hoops.

If they had put a checkbox somewhere to tell the whole workspaces thing to fuck off and be a normal desktop, I wouldn't have had an issue with it.

An age is called Dark not because the light fails to shine, but because people refuse to see it. -- James Michener, "Space"

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