[R] Linear model mixed with an ARIMA model

[Z ZX]

   Dear all,

   I'm looking for how can I input a linear model with an arma model,like

   log(y) = 8.95756 + 0.0346414^t - 0.1*t^2   + ut
   ut=-0.296ut-1+at-0.68at-1

   where log(y) is qudratic function ,for the time series trend,

   and get then get the residuals from the first function.

    " obersvations value - the fit value = ut"

   and fit an ARIMA(1,1,1) model for ut.

   anyway,how can I combine this two models together as a group ?

   my purpose is to  to use this mixed model forecast  'y'

   can you help me?  I will very appreciate it.


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References

   1. http://g.msn.com/8HMAENCA/2749??PS=47575