The influence of reconstruction criteria on the sensitive probes of the symmetry potential

Different criteria of constructing clusters and tracing back $\Delta$ resonances from the intermediate-energy neutron-rich HICs are discussed by employing the updated UrQMD transport model. It is found that both the phase-space and the coordinate-density criteria affect the single and the double neutron/proton ratios of free nucleons at small transverse momenta, but the influence becomes invisible at large transverse momenta. The effect of different methods of reconstructing freeze-out $\Delta$s on the $\Delta^0/\Delta^{++}$ ratio is strong in a large kinetic energy region.Comment: 8 pages, 7 fig

Prolongation Approach to B\"{a}cklund Transformation of Zhiber-Mikhailov-Shabat Equation

The prolongation structure of Zhiber-Mikhailov-Shabat (ZMS) equation is studied by using Wahlquist-Estabrook's method. The Lax-pair for ZMS equation and Riccati equations for pseudopotentials are formulated respectively from linear and nonlinear realizations of the prolongation structure. Based on nonlinear realization of the prolongation structure, an auto-B$\ddot{a}$cklund transformation of ZMS equation is obtained.Comment: Revtex, no figures, to appear in J. Math. Phys. (1996

Macroeconomics modelling on UK GDP growth by neural computing

This paper presents multilayer neural networks used in UK gross domestic product estimation. These networks are trained by backpropagation and genetic algorithm based methods. Different from backpropagation guided by gradients of the performance, the genetic algorithm directly evaluates the performance of multiple sets of neural networks in parallel and then uses the analysed results to breed new networks that tend to be better suited to the problems in hand. It is shown that this guided evolution leads to globally optimal networks and more accurate results, with less adjustment of the algorithm needed