The k-center problem with triangle inequality is that of placing k center nodes in a weighted undirected graph in which the edge weights obey the triangle inequality, so that the maximum distance of any node to its nearest center is minimized. In this paper, we consider a generalization of this problem where, given a number p, we wish to place k centers so as to minimize the maximum distance of...

We reconsider the quasi exactly solvable matrix models constructed recently by R. Zhdanov. The 2×2 matrix operators representing the algebra sl(2) are generalized to matrices of arbitrary dimension and a similar construction is achieved for the algebra sl(n). ∗† Work supported by grant no KBN 2P03B07610 1. Recently Zhdanov [1],[2] considered the realizations of the sl(2) algebra in terms of fir...

In this work we introduce a generalization of the Jauch and Rohrlich quantum Stokes operators when the arrival direction from the source is unknown a priori. We define the generalized Stokes operators as the Jordan-Schwinger map of a triplet of harmonic oscillators with the GellMann and Ne’eman SU(3) symmetry group matrices. We show that the elements of the Jordan-Schwinger map are the constant...

* Correspondence: [email protected]. kr Department of Mathematics, Daejin University, Kyeonggi 487711, Korea Full list of author information is available at the end of the article Abstract Using fixed point method, we investigate the Hyers-Ulam stability and the superstability of partial generalized Jordan derivations on Banach modules related to Jensen type functional equations. Mathematics Subj...