Computer Science Puzzle: Finding the Maximal Sum of a Vector
While this is a physics-oriented blog, computer science has some great puzzles, too! If you’re a professional computer scientist they’ll probably be easy for you, or you’ll already know the answer, but for anyone who isn’t familiar with the ropes, they can be very challenging. It’s always good to learn something new, too.
This week’s puzzle […]
Google’s PageRank (Sort of) Explained
In this post we’ll take a look at the algorithm which defines Google’s pagerank (PR) analysis. A webpage’s PR is a number between 0 and 10 that Google uses to estimate the usefulness of that page. For example, CNN.com has a PR of 9. A “typical” web site might have a PR of 5. Pages […]
Neural Networks Tutorial, Part #3
In our previous tutorial we’ve laid out the basic form of our two layer feed-forward neural network (FFNN). In this installment we’ll derive a way of training it. Just to remind you, here is the basic outline of our neural network, along with all relevant variables:
In general, when training a network, one prepares a […]
Neural Networks Tutorial, Part #2
A Short Review
In the previous part of our tutorial, I’ve spoken about feed forward neural networks (FFNN), and said that the basic building block of a FFNN is a layer, which can be concisely summarized using the following diagram:
A layer has N inputs and M outputs (schematically represented here by a single line at […]
MATLAB Speed: Using the M-Lint Utility
A great deal of my work is done in MATLAB these days, and I come across many neat little features of the language and the IDE that are hidden among the menus. Sure, you’d know all about them if you read the manual, but who has time for that?
Here is a little trick to help […]
Neural Networks Tutorial, Part #1
This is the first part of a set of postings on neural networks (NNs). NN are constructs that attempt to mimic our brain’s activity to a degree. NNs have become so common that it’s useful to know what people are talking about, so I’ve decided to write a brief tutorial - in several parts - […]