(A) study on unbalanced linear model having missing cells

Abstract

It has been found that there are some relationships between the projection matrix of unbalanced model and that of corresponding balanced model(Sunwoo, 1990). The corresponding balanced model is defined to be the model containing exactly one observation in each cell whether some cells are empty or not. By this method much of the computational storage can be reduced because these results can be accomplished by handling matrices having small order. Unfortunately the results of the balanced model cannot be used directly if there are some missing cells. For this reason the projection matrix of the balanced model must be computed by another method. by some procedure we can obtain the projection matrix of the unbalanced model having missing cells and find in the case of connected model it is much easier to compute the projection matrix.