Tetsuya Shoji

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Hi everyone, My name is Tetsuya Shoji from Toyota Motor Corporation, Japan.

I obtained Doctor degree in Material Science at Hokkaido University in 2003.

My doctoral research is on the Collective Dislocation Behavior during plastic deformation of Metals. In order to express Collective Dislocation motion and reaction(dislocation density evolution equation), I chose Reaction-Diffusion equation (hereafter R-D Eq.). According to my best knowlegde, the first attempt to descrive Collective Dislocation behavior with R-D Eq. was propsed by D.Walgraef et al in 1989. So, I refered Walgraef's work and set up my own equation that suite to describe the Collective dislocation behavior in FCC metal (e.g. Cu, Au and Ag) single crystal during tensile test. This model can reproduce formation process of dislocation micro-structure along stress-strain curve.

I'm looking forward to meet you in Summer School and discuss many things about Complex system.

My answer for Dan's questions is as follows.

1. What topics do you have some expertise in and would you be willing to help others learn them?

Almost whole rigion of Material Science and related phenomena

Thermo dynamics in Material Science and its computation model

Some area of non-linear R-D system and its analysis

BUT, I have not learned statistical mechanics in non-equilibrium system systematic way. So my knowledge about statictical mechanics in non-equilibrium system is biased in some region(^-^;)

2. What do you want to learn?

Scaling law

Relation between self-organization phenomena and its power spectre

Non-extensive entropy and related issue

3. Do you have any projects that would benefit from interdisciplinary approach?

I want to discuss structural controllability of materials in some kind of non-linear dynamic system. So, I expect some participant is interested in collective behavior of some kind of agent which interact each other in non-linear dynamic system. In this case, strength of interaction is very important. For example, if interaction were too weak, agent of the system will not happen to make correlation. In contrast, interaction is too strong, agent will segregate. So, some interesting phenomena will take place in the system with intermediate interaction strength, for example, it would be realized at phase transformation point. I think collective behavior of agents can be varied in static system to dynamic system. In static system, agent will move and interact each other to relax internal energy of the system to extrimum small value and achieve steady state as is well known problem. When it comes to dynamic system, I want to define dynamic system as the system with dynamical input of energy, it isn't meaned merely steady energy input, agent will work to dissipate the energy as efficient as possible. During dissipation, agent will form some kind of spatio-temporal pattern. So I want to know how we can control morphology of spatio-temporal pattern and its hieralchical structure in the system with dynamic energy input.

4. Do you have any ideas for what sort of project you would like to attack this summer?

Structural controlability of the system with dynamic energy input

5. What's your favorite "big problem"?

My "big problem" is very small one (^-^;) Where is the boundary between continuum and discrete problem. How much number of element or agent is needed to deal the system as continuum. In contrast, what kind of system we have to deal the system as discrete system.

6. If you were given the opportunity to see where we were in one hundred years with respect to progress on one problem/subject, what would it be?

I want to see how power distribution of the world changes with long time period and what may trigger such power distribution transition.