These proceedings consist of ten carefully refereed and selected papers which were presented at the 12th symposium of Tunisian Mathematical Society held on March 18-23, 2004 in Mahdia (Tunisia). This symposium was one of the largest international meeting on Mathematics in Tunisia. A total of 200 participants from several countries attended to the meeting. In addition to the plenary, invited and contributed talks, there was a panel discussion on future research directions and problems in various areas of mathematics.

This is the first of two volumes dedicated to the centennial of the distinguished mathematician Selim Grigorievich Krein. The companion volume is Contemporary Mathematics, Volume 734. Krein was a major contributor to functional analysis, operator theory, partial differential equations, fluid dynamics, and other areas, and the author of several influential monographs in these areas. He was a prolific teacher, graduating 83 Ph.D. students. Krein also created and ran, for many years, the annual Voronezh Winter Mathematical Schools, which significantly influenced mathematical life in the former Soviet Union. The articles contained in this volume are written by prominent mathematicians, former students and colleagues of Selim Krein, as well as lecturers and participants of Voronezh Winter Schools. They are devoted to a variety of contemporary problems in functional analysis, operator theory, several complex variables, topological dynamics, and algebraic, convex, and integral geometry.

Network algebra considers the algebraic study of networks and their behavior. It approaches the models in a sharp and simple manner. This book takes an integrated view of a broad range of applications, varying from concrete hardware-oriented models to high-level software-oriented models.

This book includes selected papers presented at the MIMS (Mediterranean Institute for the Mathematical Sciences) - GGTM (Geometry and Topology Grouping for the Maghreb) conference, held in memory of Mohammed Salah Baouendi, a most renowned figure in the field of several complex variables, who passed away in 2011. All research articles were written by leading experts, some of whom are prize winners in the fields of complex geometry, algebraic geometry and analysis. The book offers a valuable resource for all researchers interested in recent developments in analysis and geometry.

This book introduces an original fractional calculus methodology (‘the infinite state approach’) which is applied to the modeling of fractional order differential equations (FDEs) and systems (FDSs). Its modeling is based on the frequency distributed fractional integrator, while the resulting model corresponds to an integer order and infinite dimension state space representation. This original modeling allows the theoretical concepts of integer order systems to be generalized to fractional systems, with a particular emphasis on a convolution formulation.

This book constitutes the proceedings of the Second International Conference on Cryptology in Africa, AFRICACRYPT 2009, held in Gammarth, Tunisia, on June 21-25, 2009. The 25 papers presented together with one invited talk were carefully reviewed and selected from 70 submissions. The topics covered are hash functions, block ciphers, asymmetric encryption, digital signatures, asymmetric encryption and anonymity, key agreement protocols, cryptographic protocols, efficient implementations, and implementation attacks.

This volume contains the papers accepted for presentation at Africacrypt 2023, the 14th International Conference on the Theory and Application of Cryptographic Techniques in Africa. The 21 full papers included in this book were carefully reviewed and selected from 59 submissions. They were organized in topical sections as follows: Post-quantum cryptography; Symmetric cryptography; Cryptanalysis; Blockchain; Lattice-based cryptography; Implementations; Theory.