Parameter-tuning networks: Experiments and active-walk model

¹  Department of Modern Physics, University of Science and Technology of China - Hefei, 230026, China
²  Institute of Plasma Physics, Chinese Academy of Sciences - Hefei, 230031, China
³  Shanghai Academy of System Science and University of Shanghai for Science and Technology Shanghai, 230093, China

Corresponding author: hxp@mail.ustc.edu.cn

Received: 23 March 2008
Accepted: 2 June 2008

Abstract

The tuning process of a large apparatus of many components could be represented and quantified by constructing parameter-tuning networks. The experimental tuning of the ion source of the neutral beam injector of the HT-7 Tokamak is presented as an example. Stretched-exponential cumulative degree distributions are found in the parameter-tuning networks. An active-walk model with eight walkers is constructed. Each active walker is a particle moving with friction in an energy landscape; the landscape is modified by the collective action of all the walkers. Numerical simulations show that the parameter-tuning networks generated by the model also give stretched exponential functions, in good agreement with experiments. Our methods provide a new insight to understand the action of humans in the parameter-tuning of experimental processes, and our model could be helpful for the experimental research and other optimization problems.