Browsed by
Category: Energy-based Models

Start Here: Statistical Mechanics for Neural Networks and AI

Start Here: Statistical Mechanics for Neural Networks and AI

Comments 0 Comment

Your Pathway through the Blog-Maze: What to read, and what order to read things in, if you’re trying to teach yourself the rudiments of statistical mechanics – just enough to get a sense of what’s going on in the REAL deep learning papers. As we all know, there’s two basic realms of deep learning neural networks. There’s the kind that only requires (some, limited) knowledge of backpropagation. That’s first semester undergraduate calculus, and almost everyone coming into this field can…

Read More Read More

Generative vs. Discriminative – Where It All Began

Generative vs. Discriminative – Where It All Began

Comments 0 Comment

Working Through Salakhutdinov and Hinton’s “An Efficient Learning Procedure for Deep Boltzmann Machines”   We can accomplish a lot, using multiple layers trained with backpropagation. However (as we all know), there are limits to how many layers that we can train at once, if we’re relying strictly on backpropagation (or any other gradient-descent learning rule). This is what stalled out the neural networks community, from the mid-1990’s to the mid-2000’s. The breakthrough came from Hinton and his group, with a…

Read More Read More

What We Really Need to Know about Entropy

What We Really Need to Know about Entropy

Comments 3 comments

There’s This Funny Little “Gotcha” Secret about Entropy: Nobody mentions this secret. (At least in polite society.) But here’s the thing – entropy shows up in all sorts of information theory and machine learning algorithms. And it shows up ALONE, as though it sprung – pure and holy – from the head of the famed Ludwig Boltzmann. What’s wrong with this is that: entropy never lives alone, in isolation. In the real world, entropy exists – always – hand-in-hand with…

Read More Read More

Wrapping Our Heads Around Entropy

Wrapping Our Heads Around Entropy

Comments 5 comments

Entropy – the Most Powerful Force in the ‘Verse:   Actually, that’s not quite true. The most powerful force in the ‘verse is free energy minimization. However, entropy is half of the free energy equation, and it’s usually the more complex half. So, if we understand entropy, then we can understand free energy minimization. If we understand free energy minimization, then we understand all the energy-based machine learning models, including the (restricted) Boltzmann machine and one of its most commonly-used…

Read More Read More

A “Hidden Layer” Guiding Principle – What We Minimally Need

A “Hidden Layer” Guiding Principle – What We Minimally Need

Comments 6 comments

Putting It Into Practice: If we’re going to move our neural network-type architectures into a new, more powerful realm of AI capability, we need to bust out of the “sausage-making” mentality that has governed them thus far, as we discussed last week. To do this, we need to give our hidden layer(s) something to do besides respond to input stimulus. It’s very realistic that this “something” should be free energy minimization, because that’s one of the strongest principles in the…

Read More Read More

Statistical Mechanics, the Future of AI, and Personal Stories

Statistical Mechanics, the Future of AI, and Personal Stories

Comments 0 Comment

Statistical Mechanics and Personal Stories (On the Same Page!)   Yikes! It’s Thursday morning already. I haven’t written to you for three weeks. That’s long enough that I have to pause and search my memory for my username to get into the website. Thanksgiving was lovely. The Thursday after that was grading, all day – and for several days before and after. By now, I (and most of you) have had a few days of recovery, from what has been…

Read More Read More

Machine Learning: Multistage Boost Process

Machine Learning: Multistage Boost Process

Comments 0 Comment

Three Stages to Orbital Altitude in Machine Learning Several years ago, Regina Dugan (then Director of DARPA) gave a talk in which she showed a clip of epic NASA launch fails. Not just one, but many fails. The theme was that we had to risk failure in order to succeed with innovation. This YouTube vid of rocket launch failures isn’t the exact clip that she showed (the “action” doesn’t kick in for about a minute), but it’s pretty close. For…

Read More Read More

Neg-Log-Sum-Exponent-Neg-Energy – That’s the Easy Part!

Neg-Log-Sum-Exponent-Neg-Energy – That’s the Easy Part!

Comments 12 comments

The Surprising (Hidden) “Gotcha” in This Energy Equation: A couple of days ago, I was doing one of my regular weekly online “Synch” sessions with my Deep Learning students. In a sort of “Beware, here there be dragons!” moment, I showed them this energy equation from the Hinton et al. (2012) Nature review paper on acoustic speech modeling: One of my students pointed out, “That equation looks kind of simple.” Well, he’s right. And I kind of bungled the answer,…

Read More Read More