Abstract:
Parameter estimation in mathematical modeling is a somewhat tricky matter. As it is a
mathematical process, there are several software packages available for this purpose.
Most parameter estimation packages suffer from two serious drawbacks that inhibit their
ability to optimize parameters. One is that a model normally needs to be partially
recorded in the estimation program in order to communicate with an estimation program
and the other is that the performance of many estimators is seriously degraded when
optimizing parameters for large numerical models. PEST (Parameter ESTimation) is a
software package that can be used to overcome these difficulties in parameter
estimation.lt implements both traditional parameter estimations that are based on the use
of only a few parameters, as well as highly parameterized, regularized inversion that are
based on the use of hundreds of parameters.This study describes a methodology ~o£
parameter estimation using PEST program. The model used for the parameter estimation
is Lotka-Volterra Predator Prey model. Purpose of this research is to identify PEST as a
successful software approach for parameter estimation through determining the
deviation between the real world scenario and the results gained by PEST. The raw data
that has used for this study was obtained by the famous example which describes the
interaction between Lynx (a type of wildcat) and Hare (a mammal in the family of
rabbits), as measured using pelts collected by the Hudson Bay Company between 1900
and 1920. The graph obtained by the estimated parameters using PEST for the Lotkka
Volterra model will be compared with the graph obtained by so called famous
example.Through the comparison, once a parameter set has been determined for which
model behavior matches real system behavior, they are again used as initial guesses for
parameters to get much closer results with a very good approximation of parameters.