snowy river

Akita Mathematical Sciences Interest Group (AMSIG) Seminar series

2017

May 17, 17:45, Akita University, Engineering building 7, Room 209 on the second floor.

Speaker: Szilárd Zsolt Fazekas, AU, Title: Repetitions in strings

Abstract: Repetitions in character sequences are a very important topic in pattern matching and compression. The more repetitive a string is, the slower the pattern matching algorithms can process it, but the more compressible it is. Given their fundamental importance for string algorithms, a lot of effort has been dedicated to bound their number in given sequences. We will look at some of the most studied types of repetitions, runs and distinct repetitions, and the methods used to provide said bounds.
April 26, 17:45, Akita University, Engineering building 7, Room 209 on the second floor.

Speaker: Attila Egri-Nagy, AIU, Title: Hierarchical decompositions of finite automata - computational Krohn-Rhodes theory

Abstract: To understand complex structures we often decompose them into simple(r) building blocks and analyze how the pieces fit together. This talk will show how this very general method can be applied to finite automata (transformation semigroups). It means that we can use an algebraic tool to ‘understand’ any system amenable to a computational description. SgpDec computer algebra package for KRT

2016

Dec 6, 17:30, Akita University,

Speaker: Marcin Shcroeder, AIU, Title: Symmetries in a Closure Space Part 2
Nov 29, 17:30, Akita University, Engineering building 7, Room 209

Speaker: Marcin Shcroeder, AIU, Title: Symmetries in a Closure Space

Abstract: Concept of symmetry as invariance with respect to a group of transformations originated in the works of Klein (Erlangen Program) and Lie in the context of geometry. Later it became a paradigm for physics, chemistry and other disciplines of science. Finally, the ideas from the Erlangen Program stimulated the development of structuralism. However, all applications of the idea that could not refer to the context of geometry (i.e. could not use geometric coordinatization) failed to provide new results and the interest in structuralism as a universal tool for study of complex systems diminished. I will present a generalization of the formalism for symmetries that does not require coordinatization. The central concept for the formalism is that of a closure space. Before the new formalism is presented, concepts involved in closure spaces necessary for the formalism will be introduced and explained.
2016 Nov 8, Akita University, 17:30-19:00 Engineering Building 7, room 209 on the second floor

Speaker: Attila Egri-Nagy, AIU

Title: Computation as Function Evaluation - From the roots of LISP to the success of Clojure

Abstract: FORTRAN (FORmula TRANslation) was the first high-level programming language, designed for numerical computation. The second was LISP (LISt Processing), for symbolic computation. Both languages are still around. LISP is defined around the mathematical notions of function evaluation and function composition. It has a very simple syntax, thus the whole language can easily be described even on the blackboard. This talk will do exactly that, then we will proceed from the historic core of LISP to a modern incarnation: Clojure (http://clojure.org). This language will be taught at AIU from next Spring, see https://replforce.wordpress.com/2016/10/11/poetry-of-programming/ for more information.
2016 July 20, 5:00 PM, Akita University, Engineering Building No 5. 1st floor, Room 101 Speaker: Akihiro Yamamura, Akita University, Title: Research on Inverse Semigroups
2016 July 13, 5:00 PM, AIU, Classroom B203

Symmetry project kickoff meeting - series of short presentations and discussion.
2016 July 6, 5:00PM, Akita University, Engineering Building No 5. 1st floor, Room 101

Delights and Pitfalls of Generalization: Closure Space Formulation of Mathematical Theories (continued, with recap) by Marcin J. Schroeder, Akita International University
2016 Jun 22, 5:30PM!!! Delights and Pitfalls of Generalization: Closure Space Formulation of Mathematical Theories by Marcin J. Schroeder, Akita International University

Abstract: The main objective of this presentation is to show that closure space theory can be used as a uniform conceptual framework for a wide range of mathematical theories. The emphasis will be on logic, algebraic systems, topology, geometry, convexity theory, formalism for quantum mechanics, but the list of mathematical theories conceptualized with closure spaces is much longer. Closure space formulation of theories was frequently utilized for the purpose of generalization. Some dangers of generalization will be discussed.

2016 Jun 8, Moving messages by Andrew Crofts, Akita International University,

Abstract: This presentation will introduce the process of RNA localisation; a widely-used mechanism for targeting proteins to specific locations within cells. In addition to providing an overview of progress made by studying RNA localisation in rice seeds, I will also introduce both theoretical and practical aspects of some key methods and approaches employed in my own lab, and by life scientists in laboratories throughout the world. Finally, all participants will be given the opportunity to crack the genetic code.
2016 May 25, Chasing repetitions by Szilárd Zsolt Fazekas, Akita University,

Abstract: The topic is repetitions in the context of combinatorics on words. First, I will introduce basic concepts and tools used in the combinatorial study of sequences over finite alphabets. I will address the two main question sets regarding repetitions: avoidability and upper/lower bounds. After the introductory part, I will present some results about bounding repetitions and the ideas along which I am trying to create a framework for unified upper bounds on different types of repetitions.

2016 May 18, Orders on orders by Florent Domenach, Akita International University,

Abstract: In this talk, I will introduce the foundations of Formal Concept Analysis (FCA) based on the notion of order. I will start with basic concepts related with orders as binary relations to lattices, before introducing their uses in data mining. I will finish the talk with some brief presentation of two of my research themes, the first one on FCA on orders, in phylogenetic, and the second one on orders on FCA, with pattern structures for semantic analysis.

2016 May 11, Finite Diagram Semigroups, Attila Egri-Nagy, Akita International University,

Abstract: The talk will introduce semigroups as abstract algebraic structures and their natural representation as sets of transformations closed under function composition. Transformation semigroups have a nice visual representation, where multiplication corresponds to stacking diagrams. This diagrammatic approach can be extended for a larger class of semigroups. The talk will go through the applications of diagram semigroups and the current open questions, with special emphasis on their recent computational enumeration. The talk contains elementary definitions and intuitive operations only, therefore it is suitable for a wider audience.