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“Deep Learning has outlived its usefulness as a buzz-phrase”

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Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#81
post #35

Earlier quoted context omitted.

it's really a pity that after 75 years of AI research the best thing we've got is still based on gradient descent, a brute force trial and error.

As much of a pity as that after 3 billion years, all life is still based upon selection bias and random genetic mutations, a brute force trial and error?

This is a poor example considering evolution is anything but brute force trial and error. Each organism can be considered either an hypothesis or a collection of hypotheses about the background environment (https://arxiv.org/pdf/0911.1763v3.pdf, https://aeon.co/essays/consciousness-is-not-a-thing-but-a-pr...).

The algorithms which allow AlphaGo or the Libratus Poker AIs to achieve superhuman play have a direct correspondence with natural selection (and learning rate with selection strength). There is idea sharing between evolutionary game theory and learning, up to algorithms to play extensive form games with imperfect information such as this, based on replicator dynamics: http://dl.acm.org/citation.cfm?id=2617448

Evolution, per genome trajectory, also improves in its ability to evolve, as seen in evolvability.

Returning to the grandparent's original lament on stochastic gradient descent, I do agree with them. I suspect the need for better has not been seen due to non-supervised and incremental learning remaining minor areas of study. Artificial separation between learning and prediction allows "hacks" like batch-norm to somewhat suffice. It does seem unlikely that we will never need to take into account curvature of information manifolds while learning. Note that evolution uses curvature too.

Anything order than SGD has proven expensive but there are promising approximations, as found in KFAC or Projected Natural Gradient Descent, allowing me to close this post with yet another link between learning and evolution.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#82

Does this mean programming language nerds get to play too, maybe after boning up on our calculus and topology?

They already are; e.g. Jeff Dean among many others. The question is will the PL academic community play as well. Conal Elliott has done a lot of work in this area about 10 years ago. His work is beautiful but maybe before it’s time.

Interesting comment regarding Conal Elliott. I've always thought there is some similarity between probabilistic programming (specify a probabilistic model as a graph), functional reactive programming (specify some reactivity as a graph) and deep learning (specify some linear algebra / calculus / optimization operations as a graph). Too bad the word "graphical programming" would be interpreted as "visual programming" (or programming using plots and charts!) and not programming using an explicit graph structure.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#83
post #29

Earlier quoted context omitted.

this will get downvoted as all held, but I really think most socially apt people should have Facebook accounts these days

No. E.g. I'm fine with Telegram & Signal + WhatsApp & Skype for the elderly. Having no intention to become a public person, do I really need a public profile on a web site that's whole purpose is to spy on me everywhere, analyse my behavior and contacts, sell the data to others and show me ads?

I was recently testing video quality of video chats on a relatively shitty connection, and somehow Skype came out way ahead of Whatsapp and Hangouts.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#84
post #35

[Text from post] OK, Deep Learning has outlived its usefulness as a buzz-phrase. Deep Learning est mort. Vive Differentiable Programming! Yeah, Differentiable Programming is little more than a rebranding of the modern collection Deep Learning techniques, the same way Deep Learning was a rebranding of the modern incarnations of neural nets with more than two layers. But the important point is that people are now build…

it's really a pity that after 75 years of AI research the best thing we've got is still based on gradient descent, a brute force trial and error.

Its simplicity is its power. More complex methods (e.g. second order methods) tend to get attracted to saddle points and produce bad results. Some metaheuristics like evolution strategies are also used in some specific cases (reinforcement learning). Minibatch gradient descent + reasonable minibatch size + some form of momentum is the best we have.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#85
post #26

Earlier quoted context omitted.

So it's still just neural nets? Cool -- we've seen that before.

I’m in favor of getting rid of „neural“. That would help dispense with all the unhelpful discussions about how different DNNs work compared to the human brain.

I agree. I've taken to calling them computational graphs in my lab, because that's what they are. There is nothing neural about a LSTM.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#86
post #37

Earlier quoted context omitted.

Is a single SGD layer a neural net? Is an image filter or an audio filter a neural net? Is matrix multiplication a neural net? This would strain the intended definition even farther than it's already been strained. But all of those are differentiable programming, and rightly so because they're all pieces that you use and compose together to make interesting learning mechanisms, including the ones that we vaguely refe…

I'm not really buying your argument here. Neural networks are just a collection of artificial neurons. There is no requirement for multiple layers or depth of any kind.

> artificial neurons

Differentiable functions

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#87
post #41

[Text from post] OK, Deep Learning has outlived its usefulness as a buzz-phrase. Deep Learning est mort. Vive Differentiable Programming! Yeah, Differentiable Programming is little more than a rebranding of the modern collection Deep Learning techniques, the same way Deep Learning was a rebranding of the modern incarnations of neural nets with more than two layers. But the important point is that people are now build…

> It's really very much like a regular progam, except it's parameterized, automatically differentiated, and trainable/optimizable. > People are now actively working on compilers for imperative differentiable programming languages. Do you have an example of either of these things?

Erik Meijer gave a talk about this at KotlinConf last year https://www.youtube.com/watch?v=NKeHrApPWlo

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#88

Earlier quoted context omitted.

If you can’t reasonably get at or use second order information, how else are you going to optimize arbitrary objectives? Well, come to think of it it, why don’t DL approaches use BFGS instead of gradient descent?

There is literature on Quasi-Newton and Krylov Subspace methods for training Neural Networks. For example, https://dl.acm.org/citation.cfm?id=3104516 . I think the primary reason that such methods are not used much in practice is memory and computational cost: each function evaluation is expensive and you need to solve a very large system at every iteration. Also to reply to a sibling comment, you can add momentum an…

This is correct - second order methods are great in theory, but they are generally computationally prohibitive for high dimensional problems.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#89
post #74

Earlier quoted context omitted.

If you can’t reasonably get at or use second order information, how else are you going to optimize arbitrary objectives? Well, come to think of it it, why don’t DL approaches use BFGS instead of gradient descent?

Second order methods are attracted to saddle points in high dimensional spaces. The math and practice of optimizing these surfaces has a lot of nuances like this so much of the stuff you learn in your convex optimization class doesn't apply too well.

Do you have any recommendations on sources to read about this? Everything I've read discusses the use of the Hessian to not only determine you are at a saddle point but to also use its eigenvalues to escape.

Re: “Deep Learning has outlived its usefulness as a buzz-phrase”

#90

Earlier quoted context omitted.

I'm not really buying your argument here. Neural networks are just a collection of artificial neurons. There is no requirement for multiple layers or depth of any kind.

> artificial neurons Differentiable functions

Basically you're implying binary neurons, neuroevolution (which works on non-differentiable functions) etc. aren't a thing. Or at least they're not (working with) neural nets.

It's almost like SGD just made decades of AI research into neural networks just vanish.

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