Author Archives: jamesdmccaffrey

I ran into a truly fascinating research paper recently that described “xenobots”. Briefly, a xenobot is a tiny (about 4 one-hundredths of an inch in diameter — about the size of a grain of sand) programmable bio-robot made from frog … Continue reading →

I was working on the well-known IMDB movie review sentiment analysis problem The goal is to create a machine learning model that accepts the text of a movie review and predicts if the review is positive (class 1) or negative … Continue reading →

A positive and unlabeled learning (PUL) problem occurs when a machine learning set of training data has only a few positive (class 1) labeled items and many unlabeled (could be either negative class 0, or positive class 1) items. For … Continue reading →

Deep neural transformer architecture (TA) systems can be considered the successors to LSTM (long, short-term memory) networks. TAs have revolutionized the field of natural language processing (NLP). Unfortunately, TA systems are extremely complicated and implementing a TA system from scratch … Continue reading →

A few days ago I coded up a demo of anomaly detection using principal component analysis (PCA) reconstruction error. I implemented the PCA functionality — computation of the transformed data, the principal components, and the variance explained by each component … Continue reading →

I ran into an interesting idea called nucleus sampling, also called top-p sampling. Nucleus sampling is used for natural language processing (NLP) next-word prediction. Suppose you have a sentence that starts with “I got up and ran to the . … Continue reading →