Modelling illuminance indices by means of functional equations
In the year 2004 the functional-equationists celebrated the 80th birthday of the Supreme Pontiff of the church named Theory of Functional Equations (FEs) and Their Applications, Prof. János Aczél. Naturally, the 2004 issues of the journal Aequationes Mathematicae are devoted to the founder of the modern Theory of Functional Equations and the named journal as well. The present paper represents more than an occasional article. It illustrates the two major tendencies in the Theory of FEs. On the one hand deepening of the theory, on the other hand enlargement of the area of applications, which are to justify supplementarily the theory, otherwise worth the interest by itself. The author presents a functional equation model for the illuminance indices. He extends the usual ``illuminance index'' used in technical handbooks on lighting and gives gives a complete characterization of various classes of indices.
scientific article; zbMATH DE number 2130332