New Directions in Wireless Communications Research addresses critical issues in the design and performance analysis of current and future wireless system design. Intended for use by system designers and academic researchers, the contributions are by acknowledged international leaders in their field.

The Primality Testing Problem (PTP) has now proved to be solvable in deterministic polynomial-time (P) by the AKS (Agrawal-Kayal-Saxena) algorithm, whereas the Integer Factorization Problem (IFP) still remains unsolvable in (P). There is still no polynomial-time algorithm for IFP. Many practical public-key cryptosystems and protocols such as RSA (Rivest-Shamir-Adleman) rely their security on computational intractability of IFP.

The 2006 Nobel Prize in Physiology or Medicine was awarded to the discoverers of RNA interference, Andrew Fire and Craig Mello. This prize, which follows “RNA” Nobels for splicing and RNA catalysis, highlights just one class of recently discovered non-protein coding RNAs. Remarkably, non-coding RNAs are thought to outnumber protein coding genes in mammals by perhaps as much as four-fold. In fact, it appears that the complexity of an organism correlates with the fraction of its genome devoted to non-protein coding RNAs. Essential biological processes as diverse as cell differentiation, suppression of infecting viruses and parasitic tra- posons, higher-level organization of eukaryotic chromosomes, and gene expression are found to be largely directed by non-protein coding RNAs. Currently, bioinformatic, high-throughput sequencing, and biochemical approaches are identifying an increasing number of these RNAs. Unfortunately, our ability to characterize the molecular details of these RNAs is significantly lacking. The biophysical study of these RNAs is an emergent field that is unraveling the molecular underpinnings of how RNA fulfills its multitude of roles in sustaining cellular life. The resulting understanding of the physical and chemical processes at the molecular level is critical to our ability to harness RNA for use in biotechnology and human therapy, a prospect that has recently spawned a multi-billion dollar industry.

This Festschrift volume contains the proceedings of the conference Mathematical Methods in Computer Science, MMICS 2008, which was held during December 17-19, 2008, in Karlsruhe, Germany, in memory of Thomas Beth. The themes of the conference reflected the many interests of Thomas Beth. Although, these interests might seem diverse, mathematical methods and especially algebra as a language constituted the common denominator of all of his scientific achievements.

The purpose of this book is to give the reader two things, to paraphrase Mark Twain: Roots to know the basics of modeling networks and Wings to fly away and attempt modeling other proposed systems of interest. The Internet phenomenon is affecting us all in the way we communicate, conduct business, and access information and entertainment. More unforeseen applications are still to come. All of this is due to the existence of an efficient global hi- performance network that connects millions of users and moves information at a high rate with small delay.

The Akaike information criterion (AIC) derived as an estimator of the Kullback-Leibler information discrepancy provides a useful tool for evaluating statistical models, and numerous successful applications of the AIC have been reported in various fields of natural sciences, social sciences and engineering.

The 15th International Workshop on Conceptual Structures ICCS 2007 brings together numerous discussions between international groups of researchers from the field of Information and Communications Technology (ICT). At ICCS 2007 some of the world’s best minds in information technology, arts, humanities and social science will meet to explore novel ways that ICT can augment human intelligence.

Due to the rapid growth of digital communication and electronic data exchange, information security has become a crucial issue in industry, business, and administration. Modern cryptography provides essential techniques for securing information and protecting data.

Combining research approaches from biology, philosophy and linguistics, the field of Biosemiotics proposes that animals, plants and single cells all engage in semiosis – the conversion of objective signals into conventional signs. This has important implications and applications for issues ranging from natural selection to animal behavior and human psychology, leaving biosemiotics at the cutting edge of the research on the fundamentals of life.

This book is an evolution from my book A First Course in Information Theory published in 2002 when network coding was still at its infancy. The last few years have witnessed the rapid development of network coding into a research ?eld of its own in information science. With its root in infor- tion theory, network coding has not only brought about a paradigm shift in network communications at large, but also had signi?cant in?uence on such speci?c research ?elds as coding theory, networking, switching, wireless c- munications,distributeddatastorage,cryptography,andoptimizationtheory. While new applications of network coding keep emerging, the fundamental - sults that lay the foundation of the subject are more or less mature. One of the main goals of this book therefore is to present these results in a unifying and coherent manner. While the previous book focused only on information theory for discrete random variables, the current book contains two new chapters on information theory for continuous random variables, namely the chapter on di?erential entropy and the chapter on continuous-valued channels. With these topics included, the book becomes more comprehensive and is more suitable to be used as a textbook for a course in an electrical engineering department.