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Analog Computers

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Re: Analog Computers

#71

Post by peterburkimsher »

sleet wrote: post #57
peterburkimsher wrote: post #55

My boss at my previous job at Fisher & Paykel Healthcare in New Zealand is using analogue computing today. He developed Pertecs, which is a rudimentary analog computer paradigm written in C. http://tcode.auckland.ac.nz/~mark/Signal%20Processing%3A%20P... He got me to write some code to compile schematic diagrams into the XML config files. He's also done something similar now to compile from LaTeX, and he ported the c…

I believe the $75k minimum salary is for non-skilled jobs (the point being, if you're in a non-skilled but 'high' paying role we're still interested in you). The minimum salary for skilled jobs is $50k [1][2] That and I doubt you would find many people working at F&P Healthcare that earn less than $75k. [1] https://www.immigration.govt.nz/about-us/media-centre/news-n... [2] https://www.immigration.govt.nz/employ-migr…

"we're" - it sounds like you're connected to NZ immigration! I can fill you in with more details if you're interested.

$75k is 4x my current salary in Taiwan. Yes, I know the economy is totally different in NZ, but I don't have high hopes that changing country will suddenly make me become rich. My boss here pays me the minimum that the government allows for a Masters graduate on a foreigner work visa.

The other consideration is my girlfriend. She applied for Working Holiday, but wasn't one of the 600 lucky ones. We were in an internet café with the fastest connection in Kaohsiung, but the site just wouldn't load in time. She's 30, so she can't try again next year. If we wanted to get a partnership visa, we would have to live together and share a bank account for 1 year. Getting married doesn't even help, just living arrangements.

We're getting kind of sidetracked from the original topic of analog computers, but if it's something you want to talk about more, then just search for my name on Facebook and send me a message. It would be nice to personify the immigration forms.

Re: Analog Computers

#72

Post by adrianN »

JKCalhoun wrote: post #67
robotresearcher wrote: post #25

Earlier quoted context omitted.

> Usually no more than 3 or 4 decimal places are possible By that do you mean accurate to 1 part in 100 (3dp) or 1000 (4dp) or what? Since the scale of a representation is arbitrary, I'm not sure what dp means here.

Kind of seems like if you are measuring the analog computers virility by the number of decimal places it can represent maybe you are mis-using the machine. I mean how many decimal places can you or I do in our head in real-time?

If you're for example an archer you can "calculate" angles and velocities to a pretty high precision.

Re: Analog Computers

#73

Post by JKCalhoun »

adrianN wrote: post #72
JKCalhoun wrote: post #67

Earlier quoted context omitted.

Kind of seems like if you are measuring the analog computers virility by the number of decimal places it can represent maybe you are mis-using the machine. I mean how many decimal places can you or I do in our head in real-time?

If you're for example an archer you can "calculate" angles and velocities to a pretty high precision.

I agree, but I don't think it is "calculated" in decimal places (if the makes sense). Sort of like how slide rules didn't give you "decimal precision".

Re: Analog Computers

#74

Post by ChuckMcM »

JKCalhoun wrote: post #65
ChuckMcM wrote: post #61

I have fond memories of building an analog computer as a project from Popular Electronics that simulated a lunar lander mission. At reset you had fuel, altitude, horizontal and vertical velocity. Your input was an angle and a thrust knob (two potentiometers) and a comparative that latched when altitude reached 0 based on your velocities being less than 1m/s. It was tremendous fun to play but no graphics, just some mA…

Sounded cool, so searched for it. Page 41: http://www.americanradiohistory.com/Archive-Elementary-Elect...

Great! That is definitely the thing I built so other than wrong magazine name and it went up instead of down, it's exactly like I remember it :-)

Re: Analog Computers

#75

Post by vortico »

ramgorur wrote: post #49
mgraczyk wrote: post #20

Earlier quoted context omitted.

What you're describing is generally accepted to be physically unrealizable. In fact, the sentence that follows your quoted sentence cites two commonly known physical limitations that prevent the existence of your "computational class above and beyond Turing". Whether or not there exist physically realizable computations that are not computable by a turing machine is an open question, but most physicists and computati…

>"computational class above and beyond Turing" what does it mean?

Roughly, a computer that can solve problems in polynomial time which do not have a polynomial time algorithm on a Turing machine, which is the same class of computers we use today.

Re: Analog Computers

#76

Post by ankurdhama »

>In analog computers there are no algorithms, no loops, nothing as they know it. Instead there are a couple of basic, yet powerful computing elements that have to be interconnected cleverly in order to set up an electronic analog of some mathematically described problem.

This is exactly why the digital computer has won over the analog computer.

Re: Analog Computers

#77

Post by orbifold »

janekm wrote: post #28

Analog computing makes a lot of sense in the context of genetic algorithms and "deep learning" and I wouldn't be surprised if there's already some ASICs under design using those principles. One big challenge is that the design kits from the foundries aren't likely to include all the analog computer cells that would be needed (but perhaps for example a current mirror into a MIM capacitor could make for an integrator?)…

You can look into neuromorphic computing, there are several projects that use digital-analog hybrid systems to implement neural networks.

Re: Analog Computers

#78

Post by alimw »

ramgorur wrote: post #13

It's strange that the article does not mention anything about hydraulic macroeconomics and MONIAC, they were once widely used to verify theories in economics. https://en.wikipedia.org/wiki/MONIAC https://en.wikipedia.org/wiki/Hydraulic_macroeconomics

So this looks interesting, but my first thought is how can a conserved quantity like water model something like money that is created and destroyed?

Re: Analog Computers

#79

Post by dom0 »

ankurdhama wrote: post #76

>In analog computers there are no algorithms, no loops, nothing as they know it. Instead there are a couple of basic, yet powerful computing elements that have to be interconnected cleverly in order to set up an electronic analog of some mathematically described problem. This is exactly why the digital computer has won over the analog computer.

Uhm, no. Analogue vs. digital computers use fundamentally different kinds of computation. Analogue computers were not used for "programming", nor was it really necessary for the simulations done on them.

Essentially, with an analogue computer you have a rack full of analogue building blocks and you build an electronic system equivalent to your real-world system from them. Then you can apply inputs and observe outputs. Often, the inputs were connected to sensors in a device, and the outputs were connected to actuators or recorders.

When analogue computers were already in wide use, there were maybe three digital computers on the whole planet. Later still, in the 60s to perhaps the early 80s "analogue computers" could (to varying degrees) perform some simulations orders of magnitude faster than contemporary digital computers. Only when digital computers became fast, cheap and easy enough to do these they became a replacement, however, moving from an analogue computer to a digital program could be quite difficult, since the two operate in vastly different ways.

Large systems often used digital computers since the ~70s for e.g. recording and analyzing outputs: a company in my home town developed test rigs for performance and crash testing of cars (and also did the testing to some extent); they still had a massive hybrid computer in the 80s (multiple analogue racks plus I think two DG Nova systems).

Re: Analog Computers

#80

Post by dom0 »

oldandtired wrote: post #45
smitherfield wrote: post #35

>The human brain is a great example – its processing power is estimated at about 38 petaflops, about two-fifths of that of TaihuLight. Huh? So we now have computers more powerful than the human brain? I thought that was still some decades off. And how would one even measure such a thing? In the apples-to-apples comparison, a stupid human trick floating-point calculation savant might manage 1 flop/s.

In speed yes, in terms of continuous parallel computing power at low energy levels, technology hasn't come even close. In terms of sensory input and processing, not even close. I find it amusing that there is much hype about computer systems beating humans in very specialised areas, such as go and chess. But the missing piece here is that the human is still doing this while continuously processing all the sensory inp…

> one and only one subject matter at a speed many magnitudes faster and is only just getting ahead.

+1

Kasparov didn't simulate 200 million moves per second to make his move.

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