We frequently need to find the nearest hospital, surgery or supermarket. A map divided into cells, each cell covering the region closest to a particular centre, can assist us in our quest. Such a map is called a Voronoi diagram, named for Georgy Voronoi, a mathematician born in Ukraine in 1868. He is remembered today mostly for his diagram, also known as a Voronoi tessellation, decomposition, or partition. [TM108 or search for “thatsmaths” at irishtimes.com].

## Posts Tagged 'Algorithms'

### Voronoi Diagrams: Simple but Powerful

Published February 2, 2017 Irish Times Leave a CommentTags: Algorithms, Geometry

### The Shaky Foundations of Mathematics

Published December 1, 2016 Irish Times Leave a CommentTags: Algorithms, Logic, Number Theory

The claim is often made that mathematical results are immutable. Once proven, they remain forever valid. But things are not so simple. There are problems at the very core of mathematics that cast a shadow of uncertainty. We can never be absolutely sure that the foundations of our subject are rock-solid [TM104 or search for “thatsmaths” at irishtimes.com].

The ancient Greeks put geometry on a firm footing. Euclid set down a list of axioms, or basic intuitive assumptions. Upon these, the entire edifice of Euclidean geometry is constructed. This axiomatic approach has been the model for mathematics ever since.

### A Toy Example of RSA Encryption

Published August 11, 2016 Occasional Leave a CommentTags: Algorithms, Computer Science

The RSA system has been presented many times, following the excellent expository article of Martin Gardner in the August 1977 issue of *Scientific American*. There is no need for yet another explanation of the system; the essentials are contained in the Wikipedia article RSA (cryptosystem), and in many other articles.

The purpose of this note is to give an example of the method using numbers so small that the computations can easily be carried through by mental arithmetic or with a simple calculator.

### Can Mathematics Keep Us Secure?

Published August 4, 2016 Irish Times Leave a CommentTags: Algorithms, Computer Science

The National Security Agency is the largest employer of mathematicians in America. Mathematics is a core discipline at NSA and mathematicians work on signals intelligence and information security (US citizenship is a requirement for employment). Why is NSA so interested in mathematics? [See TM096, or search for “thatsmaths” at irishtimes.com].

### Lateral Thinking in Mathematics

Published July 7, 2016 Irish Times Leave a CommentTags: Algorithms, Puzzles, Recreational Maths

Many problems in mathematics that appear difficult to solve turn out to be remarkably simple when looked at from a new perspective. George Pólya, a Hungarian-born mathematician, wrote a popular book, *How to Solve It*, in which he discussed the benefits of attacking problems from a variety of angles [see TM094, or search for “thatsmaths” at irishtimes.com].

### Big Data: the Information Explosion

Published June 2, 2016 Irish Times Leave a CommentTags: Algorithms, Computer Science, Graph Theory

The world is awash with data. Large data sets have been available for many decades but in recent years their volumes have grown explosively. With mobile devices and internet connections data capture is simple and with powerful computers the analysis of “big data” is feasible [see TM092, or search for “thatsmaths” at irishtimes.com].

But there are challenges: many data sets are too large and too complex to be analysed or understood using traditional data processing methods. Our current armoury of analysis techniques is inadequate and new mathematical methods are needed.

### Computus: Dating the Resurrection

Published March 17, 2016 Irish Times Leave a CommentTags: Algorithms, History

Whatever the weather, St Patrick’s Day occurs on the same date every year. In contrast, Easter springs back and forth in an apparently chaotic manner. The date on which the Resurrection is celebrated is determined by a complicated convolution of astronomy, mathematics and theology, an algorithm or recipe that fixes the date in accordance with the motions of the Sun and Moon [TM087, or search for “thatsmaths” at irishtimes.com].