The Online Encyclopedia of Integer Sequences

Suppose that, in the course of an investigation, you stumble upon a string of whole numbers. You are convinced that there must be a pattern, but you cannot find it. All you have to do is to type the string into a database called OEIS --- or simply ``Slone's'' --- and, if the string is … Continue reading The Online Encyclopedia of Integer Sequences →

The Geography of Europe is Mapped in our Genes

It may seem too much to expect that a person's geographic origin can be determined from a DNA sample. But, thanks to a mathematical technique called principal component analysis, this can be done with remarkable accuracy. It works by reducing multi-dimensional data sets to just a few variables [TM189; or search for “thatsmaths” at irishtimes.com ]. … Continue reading The Geography of Europe is Mapped in our Genes →

Dimension Reduction by PCA

We live in the age of ``big data''. Voluminous data collections are mined for information using mathematical techniques. Problems in high dimensions are hard to solve --- this is called ``the curse of dimensionality''. Dimension reduction is essential in big data science. Many sophisticated techniques have been developed to reduce dimensions and reveal the information … Continue reading Dimension Reduction by PCA →

Pooling Expertise to Tackle Covid-19

Our lives have been severely restricted in recent months. We are assured that the constraints have been imposed following “the best scientific advice”, but what is the nature of this advice? Among the most important scientific tools used for guidance on the Covid-19 outbreak are mathematical models [TM188; or search for “thatsmaths” at irishtimes.com ]. A … Continue reading Pooling Expertise to Tackle Covid-19 →