In computing, Extract, Transform and Load (ETL) refers to a process in database usage and especially in data warehousing that performs: Data extraction â extracts data from homogeneous or heterogeneous data sources.
(Beginner) Reading astronomy books, I've come up with the word singularity a lot, but I can't figure out what it exactly means. A singularity means a point where some property is infinite. For example, at the center of a black hole, according to classical theory, the density is infinite (because a finite mass is compressed to a zero volume). Hence it is a singularity.
In the mathematical theory of singularities a cusp is a type of singular point of a curve. Cusps are local singularities in that they are not formed by self intersection points of the curve.The plane curve cusps are all diffeomorphic to one of the following forms: x 2 â y = 0, where k â¥ 1 is an integer. An ordinary cusp is given by x 2 â y 3 = 0, i.e. the zero-level-set of a type A 2 -singularity. 2  Let f (x, y) be a smooth function of x and y and assume, for simplicity, that f (0,0) = 0. 3  Then a type A 2 -singularity of f at (0,0) can be characterised by: