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jkabrg

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Makridakis time-series forecasting competitions

en.wikipedia.org

2 pointsby jkabrgvor 8 Jahren0 comments

DVC (Data science Version Control)

1 pointsby jkabrgvor 8 Jahren0 comments

Feature request: Only allow upvotes from users with enough karma

5 pointsby jkabrgvor 8 Jahren5 comments

comments

vor 8 Jahrendiscuss

OK, fair enough.

vor 8 Jahrendiscuss

You're judging Nietzsche using circular logic.

You're saying that because he's respected by some academics, he is objectively worthy of respect. But that's contingent on those very same academics being worthy of respect. And I'm not sure that they are, personally.

This is a major problem in academia and other areas. The academics end up being judged by fellow academics, and any claim to merit becomes completely circular. That's how you end up with things like Brutalist architecture -- it's because the architects are seeking approval from fellow architects; and not the people who have to live in, and around, what they build.

Even worse, those academics who "suck up" to other academics end up having the favour returned to them. He scratches your back, you scratch his, then he scratches yours again... You end up with citation rings.

See Taleb's Skin In The Game.

vor 8 Jahrendiscuss

If you're using Firefox, use the reader mode.

vor 8 Jahrendiscuss

See the slides example

vor 8 Jahrendiscuss

> repairing a cable is really easy task generally

Highly subjective. Some people have other hobbies.

> make the cable replaceable, i.e. have it also be connectorized on the headphone end.

I might try that.

vor 8 Jahrendiscuss

Problem with non-wireless headphones is that they break. One side of the headphones stops playing sounds; you can sometimes spin the connector and get the sound back, but that gets annoying, and it stops working eventually. The less wires and connectors, the less things can break, no?

vor 8 Jahrendiscuss

I'm wondering how many of the complaints here are to do with FrontPage itself, or the very idea of WYSIWYG web design.

To me, it seems that web design is a visual thing. And if so, then a WYSIWYG editor is the appropriate thing to use. I'm suspicious that some people here don't think visually, and don't see the value in thinking visually.

I don't know what people mean when they say "bad markup". I imagine it might include things like positioning elements using absolute coordinates. But I'm sure this is solvable by previewing the webpage on different resolutions, browsers and device types.

vor 8 Jahrendiscuss

If you like quaternions, you should check out the split-quaternions. They're equivalent to the 2x2 matrices, but help you understand them better by using analogies to the highly familiar and intuitive quaternions.

vor 8 Jahrendiscuss

Nassim Taleb had some negative things to say about GARCH.

"GARCH does not work out of sample. It is a good story, but I was unable to use it in predicting squared deviations or mean deviations"

I haven't found it in Rob J Hyndman's forecasting tutorial either.

How does it fare in the Makridakis competitions?

vor 8 Jahrendiscuss

There was a Quanta Magazine article talking about predicting the evolution of a flame-front using ML. The ML algorithm remained accurate for eight Lyapunov intervals; eight times longer than the previous SOTA.

https://www.quantamagazine.org/machine-learnings-amazing-abi...

vor 8 Jahrendiscuss

There is an interesting correspondence between red, green and blue geometries and hypercomplex numbers.

The quadratic form in Blue is the norm squared of the complex numbers.

The quadratic form in Red is the norm squared of the split-complex numbers.

The quadratic form in Green is the norm squared of R⊕R, which is isomorphic to the split-complex numbers.

There's also the dual numbers. They're the only remaining 2d unitary algebra over the Real numbers, but they don't feature in the above paper.

vor 8 Jahrendiscuss

Can someone explain how this works?

We've got the following chip companies: Intel, AMD, Samsung.

And we've got a bunch of "fab" companies: Intel, TSMC, Global Foundries, Samsung.

What's the difference between the two sets of companies? Why can't Intel just buy a "7nm" processor from TSMC?

And what exactly is "7nm"? The distance between the closest transistors in a chip? Just guessing.

[edit]

From browsing Wikipedia, I gather that:

  - A chip company designs a processor. The design is in the form of a circuit diagram(?)
  - A fab company turns that diagram into a physical product.

So for example, ARM designs a chip, which then gets built by Samsung. ARM is strictly responsible for design, and Samsung provides a factory.

vor 8 Jahrendiscuss

It's not clear what he's referring to. It could be garbage collection, libraries, frameworks, optimizing compilers...

  - Garbage collection make performance unpredictable because of collection spikes. 
  - If you use a big library, you now have to load the library, which is an extra time-sink. 
  - Likewise for frameworks. 
  - Optimizing compilers optimize the 80% of our programs that don't need optimizing, and under-optimize the 20% that do.
    (This is DJB's argument.)

That might be what he's saying. He didn't say anything about dynamic vs. static typing.

Also, there's a counter-argument to this, that writing non-garbage-collected code might result in security bugs (to do with memory management). And security is a non-functional requirement that some might say is more important than speed. It's hard to judge though; there are loads of requiremenets in software dev, and it's hard to balance them.

vor 8 Jahrendiscuss

Explain?

vor 8 Jahrendiscuss

I was referring to Kirchhoff's first law which only applies to circuits -- that example is enough to show that I=dQ/dt is wrong. I wasn't considering the cases you're talking about (lightning etc.) because only one example is needed to prove an equation wrong. I could easily produce a single specific example where dQ/dt=0 but there is clearly a non-zero current present.

And you can talk about charge in an area (sort of) if you multiply charge density by area; the result has units coulombs * metre^{-1}. I thought counting charge in a cross-section of wire was something people did, one way or another, even if the units aren't Coulombs but Coulombs*metre^{-1}.

I could very easily have misunderstood something. With the clarifications above, I'm not clear on what though.

vor 8 Jahrendiscuss

The amount of charge in an area stays constant because of Kirckhoff's laws, so dQ/dt=0 always. Wouldn't a better definition be:

  I = q v . A

where q is charge density. A is an area (actually, a normal vector to some flat cross-section, with magnitude equal to size of area), and v is velocity of the charged particles. I'm using the dot product.

If we check the units: (coulombs * metres^{-3}) * (metres * seconds ^{-1}) * metres^{2} = coulombs / seconds

By the way, I fudged the above to make "charge density" have units $coulombs * metres^{-3}$. I'm not the best person at physics.

vor 8 Jahrendiscuss

I never wrote down any notes at university. My process was:

  - Review material on Moodle before lecture.
  - Go to lecture. Don't write anything.
  - Review material again on Moodle after lecture.

I don't know how you don't lose your notes, or have material missing from your notes because you were sick one day.

vor 8 Jahrendiscuss

Go fork? No.

vor 8 Jahrendiscuss

The wording is misleading. For the following reasons:

  - Variolation was common in England at the time.
  - Wikipedia says that he *inoculated* the boy with smallpox. That means variolation.

vor 8 Jahrendiscuss

He didn't infect him, he variolated him. Variolation normally causes a very mild form of smallpox -- but results in a person becoming immune to the disease. Variolation is the predecessor of vaccination.