Journal of Computational Mathematics, Vol. 21, No. 2 (MARCH 2003), pp. 175-182 (8 pages) Least-squares solution of AX B = D with respect to symmetric positive semidefinite matrix X is considered. By ...

The higher-order accuracy of flat-top kernel estimators typically comes at the sacrifice of the positive semidefinite property. Nevertheless, we show how a flat-top estimator can be modified to become ...