Steven Vajda, 1901-1995; J. Krarup. The Fermat-Weber Problem and the Lagrangian Duality Theory; C. Antoni, A. Dalena. Longest Fragment First Algorithms for Data Compression; J. Békési, et al. Linear Operators and Stochastic Dominance; E. Castagnoli. Some Properties of Dini-Derivatives of Quasiconvex Functions; J.-P. Crouzeix. Necessary Conditions for Two-Function Minimax Inequalities; F. Forgó, I. Joó. Fitting Circles and Spheres to Coordinate Measuring Machine Data; S.I. Gass, et al. On Minty Variational Principle; F. Giannessi. Single-Facility Location Problems with Arbitrary Weights; G. Jalal, J. Krarup. On Testing SLP Codes with SLP-IOR; P. Kall, J. Mayer. On Primal-Dual Path-Following Algorithms for Semidefinite Programming; E. de Klerk, et al. A Piecewise Linear Dual Procedure in Mixed Integer Programming; I. Maros. Geometrical Solution of Weighted Fermat Problem About Triangles; M. Martelli. Separation and Regularity in the Image Space; G. Mastroeni, M. Pappalardo. Dynamic Models and Generalized Equilibrium Problems; A. Maugeri. Ordering Heuristics in Interior Point LP Methods; C. Mészáros. A Tabu Based Pattern Search Method for the Distance Geometry Problem; P.M. Pardalos, Xin Liu. Programming Under Probabilistic Constraint with Discrete Random Variable; A. Prékopa, et al. Variable Metric Methods Along Geodetics; T. Rapcsák. Criteria for Generalized Monotonicity; S. Schaible. On the K - Out - of - R - From - N : F System with Unequal Element Probabilities; T. Szántai, A. Habib. A Common Root of Three Minimization Problems; B. Uhrin.

Though the volume covers 22 papers by 36 authors from 12 countries, the history in the background is bound to Hungary where, in 1973 Andras Pn§kopa started to lay the foundation of a scientific forum, which can be a regular meeting spot for experts of the world in the field. Since then, there has been a constant interest in that forum. Headed at present by Tamas Rapcsak, the Laboratory of Operations Research and Decisions Systems of the Computer and Automation Institute, Hungarian Academy of Sciences followed the tradition in every respect, namely conferences were organized almost in every second year and in the same stimulating area, in the Matra mountains. The basic fields were kept, providing opportunities for the leading personalities to give voice to their latest results. The floor has been widened recently for the young generation, ensuring this way both a real location for the past, present and future experts to meet and also the possibility for them to make the multicoloured rainbow of the fields unbroken and continuous. The volume is devoted to the memory of Steven Vajda, one of the pioneers on mathematical programming, born is Hungary. In 1992 he took part in the XIth International Conference on Mathematical Programming at Matrafiired where, with his bright personality, he greatly contributed to the good spirituality of the event. We thank Jakob Krarup for his reminiscence on the life and scientific activities of late Steven Vajda.