Ultradiscretization of the solution of periodic Toda equation

A periodic box-ball system (pBBS) is obtained by ultradiscretizing the periodic discrete Toda equation (pd Toda eq.). We show the relation between a Young diagram of the pBBS and a spectral curve of the pd Toda eq.. The formula for the fundamental cycle of the pBBS is obtained as a colloraly.Comment: 41 pages; 7 figure

On the initial value problem of a periodic box-ball system

We show that the initial value problem of a periodic box-ball system can be solved in an elementary way using simple combinatorial methods.Comment: 9 pages, 2 figure

Fundamental Cycle of a Periodic Box-Ball System

We investigate a soliton cellular automaton (Box-Ball system) with periodic boundary conditions. Since the cellular automaton is a deterministic dynamical system that takes only a finite number of states, it will exhibit periodic motion. We determine its fundamental cycle for a given initial state.Comment: 28 pages, 6 figure

Solution of the genaralized periodic discrete Toda equation

A box-ball system with more than one kind of balls is obtained by the generalized periodic discrete Toda equation (pd Toda eq.). We study the pd Toda equation in view of algebraic geometry. The time evolution of pd Toda eq. is linearized on an algebraic variety, and theta function solutions are obtained.Comment: 18pages, 1figur

Integrable structure of box-ball systems: crystal, Bethe ansatz, ultradiscretization and tropical geometry

The box-ball system is an integrable cellular automaton on one dimensional lattice. It arises from either quantum or classical integrable systems by the procedures called crystallization and ultradiscretization, respectively. The double origin of the integrability has endowed the box-ball system with a variety of aspects related to Yang-Baxter integrable models in statistical mechanics, crystal base theory in quantum groups, combinatorial Bethe ansatz, geometric crystals, classical theory of solitons, tau functions, inverse scattering method, action-angle variables and invariant tori in completely integrable systems, spectral curves, tropical geometry and so forth. In this review article, we demonstrate these integrable structures of the box-ball system and its generalizations based on the developments in the last two decades.Comment: 73 page

A tropical analogue of Fay's trisecant identity and the ultra-discrete periodic Toda lattice

We introduce a tropical analogue of Fay's trisecant identity for a special family of hyperelliptic tropical curves. We apply it to obtain the general solution of the ultra-discrete Toda lattice with periodic boundary conditions in terms of the tropical Riemann's theta function.Comment: 25 pages, 3 figure

Toda Equations and σ\sigma-Functions of Genera One and Two

We study the Toda equations in the continuous level, discrete level and ultradiscrete level in terms of elliptic and hyperelliptic $\sigma$ and $\psi$ functions of genera one and two. The ultradiscrete Toda equation appears as a discrete-valuation of recursion relations of $\psi$ functions.Comment: 16 page

The Development Status of the National Project by Technology Research Assortiation for Future Additive Manufacturing (TRAFAM) in Japan

The Ministry of Economy, Trade and Industry (METI) of Japan established Technology Research Association for Future Additive Manufacturing (TRAFAM) in order to develop AM technology in FY2014. The association’s mission is twofold; to develop metal Additive Manufacturing technology and to develop binder jetting-type machine for the rapid production of sand molds. The goal of TRAFAM project is the development of innovative metal AM systems that will meet the world’s highest standards and the development of AM technology for high value-added products for aerospace, medical, and transportation industries etc. In this paper, the latest development status of the project, especially the development status of the electron beam PBF type machines, the laser PBF type machine and the laser DED type machines, is introduced. In addition, the numerical simulation software for metal AM based on multi-scale and multi-physics model is introduced.Mechanical Engineerin