This book constitutes the refereed proceedings of the 18th International Colloquium on Structural Information and Communication Complexity, SIROCCO 2011, held in Gdańsk, Poland, in June 2011. The 24 revised full papers presented together with 1 survey lecture and 2 invited talks were carefully reviewed and selected from 57 submissions. The papers are organized in topical section on fault tolerance, routing, mobile agents, mobile robots, probabilistic methods, distributed algorithms on graphs, and ad-hoc networks.

The abstracts and papers in this volume were presented at the Fifth Annual International Computing and Combinatorics Conference (COCOON ’99), which was held in Tokyo, Japan from July 26 to 28, 1999. The topics cover most aspects of theoretical computer science and combinatorics pertaining to computing. In response to the call for papers, 88 high-quality extended abstracts were submitted internationally, of which 46 were selected for presentation by the p- gram committee. Every submitted paper was reviewed by at least three program committee members. Many of these papers represent reports on continuing - search, and it is expected that most of them will appear in a more polished and complete form in scienti c journals. In addition to the regular papers, this v- ume contains abstracts of two invited plenary talks by Prabhakar Raghavan and Seinosuke Toda. The conference also included a special talk by Kurt Mehlhorn on LEDA (Library of E cient Data types and Algorithms). The Hao Wang Award (inaugurated at COCOON ’97) is given to honor the paper judged by the program committee to have the greatest scienti c merit. The recipients of the Hao Wang Award 1999 were Hiroshi Nagamochi and Tos- hide Ibaraki for their paper \An Approximation for Finding a Smallest 2-Edge- Connected Subgraph Containing a Speci ed Spanning Tree".

Advances in microelectronic technology have made massively parallel computing a reality and triggered an outburst of research activity in parallel processing architectures and algorithms. Distributed memory multiprocessors - parallel computers that consist of microprocessors connected in a regular topology - are increasingly being used to solve large problems in many application areas. In order to use these computers for a specific application, existing algorithms need to be restructured for the architecture and new algorithms developed. The performance of a computation on a distributed memory multiprocessor is affected by the node and communication architecture, the interconnection network topology, the I/O subsystem, and the parallel algorithm and communication protocols. Each of these parametersis a complex problem, and solutions require an understanding of the interactions among them. This book is based on the papers presented at the NATO Advanced Study Institute held at Bilkent University, Turkey, in July 1991. The book is organized in five parts: Parallel computing structures and communication, Parallel numerical algorithms, Parallel programming, Fault tolerance, and Applications and algorithms.

Multiprocessing: Trade-Offs in Computation and Communication presents an in-depth analysis of several commonly observed regular and irregular computations for multiprocessor systems. This book includes techniques which enable researchers and application developers to quantitatively determine the effects of algorithm data dependencies on execution time, on communication requirements, on processor utilization and on the speedups possible. Starting with simple, two-dimensional, diamond-shaped directed acyclic graphs, the analysis is extended to more complex and higher dimensional directed acyclic graphs. The analysis allows for the quantification of the computation and communication costs and their interdependencies. The practical significance of these results on the performance of various data distribution schemes is clearly explained. Using these results, the performance of the parallel computations are formulated in an architecture independent fashion. These formulations allow for the parameterization of the architecture specitific entities such as the computation and communication rates. This type of parameterized performance analysis can be used at compile time or at run-time so as to achieve the most optimal distribution of the computations. The material in Multiprocessing: Trade-Offs in Computation and Communication connects theory with practice, so that the inherent performance limitations in many computations can be understood, and practical methods can be devised that would assist in the development of software for scalable high performance systems.

This book constitutes the refereed proceedings of the 17th International Colloquium on Structural Information and Communication Complexity, SIROCCO 2010, held in Sirince, Turkey, in June 2010. The 19 revised full papers presented were carefully reviewed and selected from 37 submissions. The volume also contains the abstract of one invited talk. The papers are organized in topical section on game theory, network algorithms, motion planning, asynchrony, network algorithms, motion planning, topology algorithms, and graph algorithms.