Author Archives: jamesdmccaffrey

What is a Self-Organizing Map?

A few days ago, one of my colleagues asked what a self-organizing map (SOM) is. SOMs are a bit tricky to explain because there are many variations. The simplest possible type of SOM is illustrated by the diagram below. Suppose … Continue reading

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Visiting N Rooms at Least Once

In a recent blog post, I described an algorithm that involved 10 rooms in a sultan’s harem. A mathematician had to visit each room. I wondered how many moves would be required, on average, for the mathematician to visit all … Continue reading

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Another Look at Microsoft Azure Functions

One of the ways I keep up with the blazing pace of new developments in technology is by doing technical reviews of journal articles (such as those in Microsoft MSDN Magazine) and technical books (such as the series of free … Continue reading

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Running the PyTorch CIFAR Example

Among my colleagues, the three most commonly used neural network libraries are TensorFlow (by itself and with Keras), CNTK, and PyTorch. I’m very familiar with Keras/TF and CNTK, but not so familiar with PyTorch. So, this morning I went to … Continue reading

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The Sultan’s Harem, Magic Parrot, and the Mathematician

Here’s an old problem. A mathematician is in a harem with 10 rooms. Each room has a different number of girls in it. The mathematician is blindfolded but has a magic parrot that knows probability. The mathematician needs to estimate … Continue reading

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Displaying an MNIST Digit Yet Once Again

It seems like there are some mini-problems that I do over and over. Displaying an MNIST digit is one such mini-problem. I’m in the process of writing an article for Visual Studio Magazine ( https://visualstudiomagazine.com/Home.aspx ) and the topic is … Continue reading

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My Top Ten Favorite Science Fiction Movies Set on an Island

I enjoy science fiction movies that are set in an isolated environment, such as an Arctic outpost, because the confined location forces writers and directors and actors to be creative. Here are my favorite science fiction films that take place … Continue reading

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