Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
×

Comment Re:Mercedes, BMW engineers are dimwits. (Score 2) 360

They saw diesel electric locomotives replace steam engines in just one decade in 1950s.

The reason was different. Diesels cost about 3x as much as steam locomotives pre-WWII. But by the 1950s, diesel engine manufacturing was a production line process and the price had come down.

The real advantage of diesel over steam was that steam locomotives are incredible maintenance-intensive. Here's daily maintenance. That's what had to be done every day, by a whole crew. That's just daily. Here's 120,000 mile maintenance, done about once a year for a road locomotive. This isn't an oil change; this is a full teardown, boiler replacement, and rebuild.

Electric cars don't have that big an edge over IC engines at this point.

Comment Should we say hello? (Score 1) 239

We could send radio signals that far, with the big dish at Arecibo. If they have intelligence, and radio, we can communicate with a 1000-year round trip time. Maybe we should transmit some of the proposed canned messages to other civilizations every month or so.

If there is other intelligent life out there, it looks like they're a very long way away. Too far to talk to round trip, even at light speed. None of the known extra-solar planets within a few light years look promising.

Comment Re:Festo has been doing this for years. (Score 1) 36

Right. Traditional pneumatics is rather dumb - most of the time it's on/off, with air cylinders pushed up against hard limit stops. Positional control of pneumatic cylinders works fine, but it takes proportional valves, feedback sensors, and a fast control system. Until recently, industrial systems tended not to get that fancy.

I was interested in using pneumatics for running robots back in the 1990s, but the available proportional valves back then were big and expensive. One useful model of muscles is two opposed springs, and a double-ended pneumatic cylinder can do just that. You can change both position and stiffness, separately. You can simulate a spring, and recover energy. Someone did that at CWRU a decade ago, but the mechanics were clunky. Festo does that elegantly with their new kangaroo. Very nice mechanical engineering.

Shadow Robotics has a nice pneumatic robot hand. Shadow has been doing pneumatic flexible actuators for many years, but now they have good controllability.

Comment Festo has been doing this for years. (Score 5, Interesting) 36

Every year, Festo, the German robotics company, builds an exotic new kind of robot as a demo. Many of their robots have been "soft".

Here's their whole list of experimental projects. They've been doing "soft robots" since 2007. Others were doing "soft robots" before that, but the control usually wasn't that good. Festo builds soft robots with smooth, precise control. Festo's specialty is precise control of pneumatic systems, so they know how to do this.

Comment E = (T2-T1) / T1 (Score 3, Informative) 174

E = (T2-T1) / T1

Everyone with an engineering degree knows this. Trying to extract much energy from low-grade heat at the output end of an engine is inefficient. This was figured out a long time ago. Here it is in The Manual of the Steam Engine. It's possible to increase steam engine efficiency by compounding, where the exhaust from each cylinder feeds a larger, lower pressure cylinder. This is cost-effective up to about 3 cylinders ("triple expansion"). Engines up to quintuple-expansion have been built, but the additional power from the last two cylinders in the chain isn't worth the trouble.

Comment Re:When will they gentrify the Tenderloin? (Score 1) 359

In 2005, this appeared in SF Weekly, about the gentrification of the Polk St. area of the Tenderloin:

Gay Shame calls the Lower Polk Neighbors Association a "brutal gentrification squad" of wealthy business owners, slumlords and bureaucrats.

"They are trying to transform Polk Street from the city's last remaining gathering place for marginalized queers and street culture into a hip destination for wealthy suburbanites," Mary said. "We want a safe place for marginalized people, and Polk Street has historically been that space.

"The neighborhood may soon be known more for green-apple mojitos and stretch Hummers than trannies and tweakers (methamphetamine users)."

That was back in 2005. Gentrification won.

Comment Re:Are you kidding (Score 2) 818

I have no sympathy. In fact, many of you cheered it as a sign of greatness and freedom that America was doing this. Your allies, however, were fucking appalled. Let

Let me finish that sentence for you:

Option 1: "Let me just say that I laugh at your situation, secure in my knowledge that nothing like that can happen where I live."

Option 2: "Let me see this as a warning that despite rule of law, foundational documents, and all the trappings of representative government, this could still happen here. I will be especially on guard against those that try to subvert my country."

Comment Re:When will they gentrify the Tenderloin? (Score 3, Interesting) 359

It's happening. First, take a look at a map of the Tenderloin, from "Areas to Avoid, San Francisco." Twitter HQ is in that area, between 9th and 10th on Market, and the long-standing "mid-Market area" around there is rapidly being rebuilt. In fact, just about everything south of McAlliister has been gentrified, except for parts of 6th St and a small section around 7th and the north side of Market. Rebuilding is underway along the Van Ness corridor too, and has more or less chopped a block off the Tenderloin on the west side. That's the old "Polk Gulch" area, once a gay rent-boy hangout.

So the SF Tenderloin is about half the size it was a few years ago. Progress continues.

Comment It's a training program, not production (Score 1) 80

This is a training program, not a production process. They have a few people doing forging by hand, but not to make production parts. See the original article in the Japan Times. Toyota's process of continuous improvement of production requires that people working on assembly lines understand the process well enough to suggest improvements. They recognize that they've dumbed down the workforce too much.

Ford Motor funded the building of the Detroit TechShop for similar reasons. They need more people who have a good sense of how stuff is made. Who in the US gets a degree in production engineering any more?

Comment Re:Overseas comment (Score 2) 386

I like the UK system - if you're an employee and you're happy with the tax your employer has withheld on your behalf, you don't have to do anything. You get a statement at the end of the year telling you how much you've been paid and how much tax has been withheld - if you think they've got it wrong, or you want to claim deductions, you file a tax return saying so.

We could do this in the US. By could I mean, if we changed tax regulations -- the system is mostly in place already. Wage income is deducted "pay-as-you-go" here, too. All of my interest, dividends and gains were already reported (but not deducted) by the entities that paid them. The IRS could have just sent me a bill for that with what they already know. Most of the data I put on my 1040 is redundant for the IRS. The biggest impediment -- other than changing the law -- would be that not claiming all your deductions could result in paying far more than you really should owe, especially if you have a mortgage, give to charity, or need to report other such deductions.

Comment Re:base it around my OS (Score 1) 386

. . . at some point you're clicking quickly because you just want to get shit done and accidentally upgrade yourself to a $120 tax package. After that, you literally cannot back out or restart.

You can, but it requires human intervention from customer service and takes a few hours. Obviously, this would be a problem if it happened at the last minute

Comment Re:Tax Act vs Turbo Tax (Score 3, Interesting) 386

Although I am moving more and more to Linux I am GOING to keep at least one Windows machine around just to run Tax Act if nothing else!

Tax Cut (H&R Block) online works with Linux browsers. Turbo Tax online complains but works anyway. And Tax Act online at least let me start without any warnings. There really seems to be little difference in the online versions of these services vs the installable Windows program, FWIW to you. I replaced my Mom's XP with Ubuntu and switched her over from Turbo Tax for Windows to Turbo Tax Online. Except for the (apparently bogus) warning when first starting, it worked fine, and she didn't really notice a difference in the experience from last year.

The paranoid might be concerned about filling out their taxes online, but the truly paranoid would note that an installable program could just as easily "phone home" with your tax info, anyway.

Slashdot Top Deals

"God is a comedian playing to an audience too afraid to laugh." - Voltaire

Working...