field rank
6.Let D be the ring of integers in the imaginary quadratic field Q() and let Cn,△n be the class number of a positive de finits Hermitian form of rank n and discriminant △n over D. In this paper the author determines Cn ,△n with n = 2, 1≤△n≤5 and n = 3, △n= 1 by usin Hermitian reduction theory to Hermitian forms over D. Representative forms of classes are exhibited.
9.The research is mainly focused on the following aspects: Based on the present AR(p) method, the AIC rule is used for fix the rank of the AR model to improve the simulation precision. Take into account that the wind speed spectrum is vary with the height for the long-span steel arch bridge, simulate the fluctuating wind field.
