To celebrate the 40th anniversary of EJC, I share some problems close to my heart. They relate mainly two areas became acquainted with more than 50 years ago during as a student at Eötvös University, Budapest. was fascinated by Ramsey theory learned course Vera T. Sós and notion perfect graphs related structures from Erdős Gallai. also impressed early developments hypergraph led Berge his Frenc...

Performance of iterative clustering algorithms which converges to numerous local minima depend highly on initial cluster centers. Generally initial cluster centers are selected randomly. In this paper we propose an algorithm to compute initial cluster centers for K-means clustering. This algorithm is based on two observations that some of the patterns are very similar to each other and that is ...