The research results published in this book range from pure mathematical theory (semigroup theory, discrete mathematics, etc.) to theoretical computer science, in particular formal languages and automata. The papers address issues in the algebraic and combinatorial theories of semigroups, words and languages, the structure theory of automata, the classification theory of formal languages and codes, and applications of these theories to various areas, like quantum and molecular computing, coding theory, and cryptography.

The research results published in this volume range from pure mathematical theory (semigroup theory, discrete mathematics, and so on) to theoretical computer science, in particular formal languages and automata. The papers are the proceedings of the Third International Colloquium on Words, Languages and Combinatorics, and they address issues in the algebraic and combinatorial theories of semigroups, words and languages, the structure theory of automata, the classification theory of formal languages and codes, and applications of these theories to various areas, like quantum and molecular computing, coding theory, and cryptography.

The research results published in this set of proceedings range from pure semigroup theory to theoretical computer science, in particular formal languages and automata. Contributed by internationally recognized researchers, the papers address issues in the algebraic and combinatorial theories of semigroups, the structure theory of automata, the classification theory of formal languages and codes and applications of these theories to various areas like circuit testing, coding theory, or cryptography. The underlying theme is the semigroup and automaton theories and their role in certain applications.

The topics included in this proceedings cover both mathematics and computer science. They include Codes, Free Monoids, Transformation Semigroups, Automata, Formal Languages, Word Problems, Orders and Combinatorics. Attention is paid to the algebraic theories of codes and rewriting systems, which are the key subjects that combine these two fields. The number of papers in the proceedings exceeds 45 and all papers have been refereed.

This volume contains one invited lecture which was presented by the 1994 Fields Medal ist Professor E. Zelmanov and twelve other papers which were presented at the Third International Conference on Algebra and Their Related Topics at Chang Jung Christian University, Tainan, Republic of China, during the period June 26-July 1, 200l. All papers in this volume have been refereed by an international referee board and we would like to express our deepest thanks to all the referees who were so helpful and punctual in submitting their reports. Thanks are also due to the Promotion and Research Center of National Science Council of Republic of China and the Chang Jung Christian University for their generous financial support of this conference. The spirit of this conference is a continuation of the last two International Tainan Moscow Algebra Workshop on Algebras and Their Related Topics which were held in the mid-90's of the last century. The purpose of this very conference was to give a clear picture of the recent development and research in the fields of different kinds of algebras both in Taiwan and in the rest ofthe world, especially say, Russia" Europe, North America and South America. Thus, we were hoping to enhance the possibility of future cooperation in research work among the algebraists ofthe five continents. Here we would like to point out that this algebra gathering will constantly be held in the future in the southern part of Taiwan.

This book constitutes the refereed proceedings of the 8th International Conference on Machines, Computations, and Universality, MCU 2018, held in Fontainebleau, France, in June 2018. The 9 revised full papers presented together with 5 invited talks were carefully reviewed and selected from numerous submissions. MCU explores computation in the setting of various discrete models (Turing machines, register machines, cellular automata, tile assembly systems, rewriting systems, molecular computing models, neural models, concurrent systems, etc.) and analog and hybrid models (BSS machines, infinite time cellular automata, real machines, quantum computing, etc.).

This is the first book devoted to the systematic study of sparse graphs and sparse finite structures. Although the notion of sparsity appears in various contexts and is a typical example of a hard to define notion, the authors devised an unifying classification of general classes of structures. This approach is very robust and it has many remarkable properties. For example the classification is expressible in many different ways involving most extremal combinatorial invariants. This study of sparse structures found applications in such diverse areas as algorithmic graph theory, complexity of algorithms, property testing, descriptive complexity and mathematical logic (homomorphism preservation,fixed parameter tractability and constraint satisfaction problems). It should be stressed that despite of its generality this approach leads to linear (and nearly linear) algorithms. Jaroslav Nešetřil is a professor at Charles University, Prague; Patrice Ossona de Mendez is a CNRS researcher et EHESS, Paris. This book is related to the material presented by the first author at ICM 2010.

Molecular computing is a rapidly growing subarea of natural computing. On the one hand, molecular computing is concerned with the use of bio-molecules for the purpose of actual computations while, on the other hand, it attempts to understand the computational nature of molecular processes going on in living cells. The book presents a unique and authorative state-of-the-art survey on current research in molecular computing: 30 papers by leading researchers in the area are drawn together on the occasion of the 70th birthday of Tom Head, a pioneer in molecular computing. Among the topics addressed are molecular tiling, DNA self-assembly, splicing systems, DNA-based cryptography, DNA word design, gene assembly, and membrane computing.

This Book is devoted to the proceedings of the Sixth International Conferenceon Number Theory and Smarandache Notions held in Tianshui during April 24-25,2010. The organizers were Prof. Zhang Wenpeng and Prof. Wangsheng He from Tianshui Normal University. The conference was supported by Tianshui Normal University and there were more than 100 participants.

This volume brings together the work of several prominent researchers who have collaborated with Janusz Brzozowski, or worked in topics he developed, in the areas of regular languages, syntactic semigroups of formal languages, the dot-depth hierarchy, and formal modeling of circuit testing and software specification using automata theory.