Thursday, 31 December 2020

Considerations in Natural Language Generation

An article slightly tangential to natural language processing but provides useful background considerations to PyCryptos operating in this space, as well as to programmers designing conversational interfaces, is this article on how phrasing affects memorability. Cornell professor Jon Kleinberg co-authors.

Wednesday, 30 December 2020

Arithmetic Dynamics

Arithmetic dynamics is a fascinating area which amalgamates number theory and dynamical systems. Number-theoretic properties of integer points (and integral-related points e.g. rational points) under the repeated application of an algorithmic rule that expresses a polynomial or rational function are studied. Joseph Silverman from Brown University is one of the field's exponents.

Monday, 7 December 2020

Essential Prerequisites for Competency in Calculus of Variations

It is not difficult to understand the need for and the objective of the calculus of variations. 

The classical brachistochrone problem and the isoperimetric problem associated with Dido of Carthage are cases in point.

However, the prerequisites for competency are not as apparent. 

A suggested list of pre-competencies are listed below.

An nonpareil familiarity with function spaces is essential to make the theoretical arguments stick. One can even say that function spaces are the biosphere in which the calculus of variations exists and flourishes.

If you don't live and breathe function spaces you may find the journey down the road of calculus of variations somewhat tough.

We can start with a simple example of C[0,1] as a warm-up example. This is the set of all functions defined and continuous on the closed interval bounded by 0 and 1.

Friday, 15 May 2020

Quantum Key Distribution

Quantum key distribution is a problem in quantum cryptography.

Wednesday, 29 April 2020

Morse Theory a Must Know for the PyCrypto

Morse Theory is the theory made up by Marston Morse from Maine, an American mathematician known for his work on "calculus of variations in the large".

The Morse-Palais Lemma is named after him and Richard Palais.

Eisenstein and Irreducibility

Gotthold Eisenstein gives his name to Eisenstein's criterion, a famous theorem on the irreducibility of polynomials with coefficients in Z to polynomial products over Q (the rationals being a larger "field" than the integers). German mathematician Theodor Schรถnemann was in fact the first to publish it.

Tuesday, 21 April 2020

Fisher Information (Info about a PopPar in an RV X)

At some point a statistician will come head-to-head with the Fisher information, which measures the "information" about a population parameter contained in an observable random variable X. 

It is the expected value of the observed information (sounds a bit like "maximum likelihood", right?).

Formally it is what statisticians call the "variance of the score".  

The notion of "score" is something quite peculiar and distinctive to this branch of mathematics and is also known as the "informant". It is the rate of change of the log likelihood function of the population parameter, with respect to the parameter.

It is named after British polymath, Sir Ronald Aylmer Fisher, FRS.