Parameter-tuning networks: Experiments and active-walk modelXiao-Pu Han1, Chun-Dong Hu2, Zhi-Min Liu2 and Bing-Hong Wang1, 3
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
received 23 March 2008; accepted in final form 2 June 2008; published July 2008
published online 2 July 2008
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.
89.75.-k - Complex systems.
89.75.Hc - Networks and genealogical trees.
05.40.Fb - Random walks and Levy flights.
© EPLA 2008