On a Generalization of the Modified Gravity Model
The modified gravity model is a nonlinear regression model for estimating passenger correspondences between pairs of spatial points [Andronov and Santalova, Simul. Comput. 41(2), 730–745 (2012)]. Unknown parameters of the model and correspondences are estimated using aggregated data, i.e. total number of passenger departures at each point in a considered time interval. The model estimation under the assumption that the error term is distributed normally is carried out in [Andronov and Santalova, Simul. Comput. 41(2), 730–745 (2012); Santalova, Autom. Control Comput. Sci. 47(2), 99–106 (2013)]. However non-symmetry of the passenger flows may violate the assumption about normality of error distribution. In the present research the model with normally distributed errors is generalized to a model with skew-normal error distribution, and a method of its estimation is proposed.
The research was supported by the European Union through the European Social Fund (Mobilitas grant No GMTMS280MJ) and Estonian Science Foundation (grant No ETF9127).
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