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A word is said to be primitive if it cannot be represented as any power of another word. It is a well-known conjecture that the set of all primitive words Q over a non-trivial alphabet is not context-free: this conjecture is still open. In this book, the authors deal with properties of primitive words over a non-primitive alphabet, the language consisting of all primitive words and related languages. Moreover, some decidable and undecidable problems with respect to the above languages are discussed as well. As another try, a search for a non-phrase structure grammar which generates Q is performed.

Japan has developed what is arguably the most sophisticated and the most democratic broadcasting system in the world. The Great Kanto Earthquake of 1st September 1923, with its devastation and confusion drove home in its appalling way the importance of being able to broadcast immediate information to the public. The same year, the Ministry of Communications promptly established an administrative system to regulate broadcasting. In less than a decade over one million people were registered listeners. Under the post war Constitution of 1946 freedom of'speech and all other forms of expression'was guaranteed, and the subsequent Broadcast Law instituted a dual system of broadcasting with the public service Nippon Hoso Kyokai (NHK) on the one hand, and commercial and private broadcasting organizations on the other. In 1978 there were ninety-one television broadcasting organizations and fifty-one radio broadcasting organizations. In this informative study, Professor Ito and his team comprehensively describe the staggering growth of broadcasting in Japan from the dawn or radio and television to satellite communication and through to the multiplex broadcasting of the future.

This book constitutes the refereed proceedings of the 12th International Conference on Developments in Language Theory, DLT 2008, held in Kyoto, Japan, September 2008. The 36 revised full papers presented together with 6 invited papers were carefully reviewed and selected from 102 submissions. All important issues in language theory are addressed including grammars, acceptors and transducers for words, trees and graphs; algebraic theories of automata; algorithmic, combinatorial and algebraic properties of words and languages; variable length codes; symbolic dynamics; cellular automata; polyominoes and multidimensional patterns; decidability questions; image manipulation and compression; efficient text algorithms; relationships to cryptography, concurrency, complexity theory and logic; bio-inspired computing; quantum computing.

The refereed proceedings of the 6th International Conference on Developments in Language Theory, DLT 2002, held in Kyoto, Japan in September 2002. The 28 revised full papers presented together with 8 invited papers were carefully reviewed and selected from 63 submissions. Among the topics addressed are grammars and acceptors for strings, graphs, arrays, etc; efficient algorithms for languages; combinatorial and algebraic properties of languages; decision problems; relations to complexity theory, logic picture description and analysis, DNA computing, cryptography, concurrency, quantum computing, and algebraic systems.

This is an excellent collection of papers dealing with combinatorics on words, codes, semigroups, automata, languages, molecular computing, transducers, logics, etc., related to the impressive work of Gabriel Thierrin. This volume is in honor of Professor Thierrin on the occasion of his 80th birthday.

There is algebraic structure in time, computation and biological systems. Algebraic engineering exploits this structure to achieve better understanding and design. In this book, pure and applied results in semigroups, language theory and algebra are applied to areas ranging from circuit design to software engineering to biological evolution.

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.

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.