Interacting many-body systems are the main subjects of research in theoretical condensed matter physics, and they are the source of both the interest and the difficulty in this field. In order to understand the macroscopic properties of matter in terms of macroscopic knowledge, many analytic and approximate methods have been introduced. The contributions to this proceedings volume focus on the most recent developments of computational approaches in condensed matter physics. Monte Carlo methods and molecular dynamics simulations applied to strongly correlated classical and quantum systems such as electron systems, quantum spin systems, spin glassss, coupled map systems, polymers and other random and comlex systems are reviewed. Comprising easy to follow introductions to each field covered and also more specialized contributions, this proceedings volume explains why computational approaches are necessary and how different fields are related to each other.

My dear friends, I am very pleased and honored to give the opening address in the first Nishinomiya-Yukawa Memorial Symposium on Theoretical Physics. Nishi nomiya City wishes to extend a warm and sincere welcome to the many participants here in this Symposium. Nishinomiya is the city where Dr. Hideki Yukawa (1907-1981) was living when he published the famous paper "On the Interactions of Elementary Particles. I" in 1935. For this work he was awarded the Nobel Prize for Physics in 1949. To celebrate the 50th anniversary of his meson theory, our city has started the "Nishinomiya-Yukawa Memorial Activities" to promote the study of the oretical physics, which, we believe, is important for the progress of human society. The annual activities consist of this Symposium, the Nishinomiya Yukawa Memorial Prize for promising young physicists and Memorial Lec tures for citizens every year. They are conducted by the Steering Committee, the chairman of which is Professor K. Nishijima, the director of the Research Institute for Fundamental Physics, Kyoto University. I would like to express my sincere gratitude to the members of this Committee for their great efforts, as well as to the members of the Organizing Committee of this Symposium. Dr. Yukawa said in his book "Tabibito" ("A traveler" in Japanese), "One who inquires into the truth is just like a traveler without a map." I shall be very happy and proud if this Symposium is successful and provides a useful map for many, particularly for young, physicists.

Many novel cooperative phenomena found in a variety of systems studied by scientists can be treated using the uniting principles of synergetics. Examples are frustrated and random systems, polymers, spin glasses, neural networks, chemical and biological systems, and fluids. In this book attention is focused on two main problems. First, how local, topological constraints (frustrations) can cause macroscopic cooperative behavior: related ideas initially developed for spin glasses are shown to play key roles also for optimization and the modeling of neural networks. Second, the dynamical constraints that arise from the nonlinear dynamics of the systems: the discussion covers turbulence in fluids, pattern formation, and conventional 1/f noise. The volume will be of interest to anyone wishing to understand the current development of work on complex systems, which is presently one of the most challenging subjects in statistical and condensed matter physics.