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where, COV (.) represents the covariance calculation.  Stochastic processes that consider project correlation typically use Cholesky decomposition matrices. This decom- position method has a prerequisite in that any given matrix must be positive definite or positive semi-definite. Suppose that A is any nxn positive definite matrix (covariance or correlation matrix) and satisfies X' AX>0 for all nonzero eigenvectors X, where X'AX denotes a 1*1 matrix, namely, a real number. Cholesky decomposition can be used when the matrix is positive definite to decompose the matrix into a lower triangular matrix C and an upper triangular matrix C’ (A=CC"). The coefficients (a,;) in matrix A can then be obtained by solving n equations via back substitution, as follows.

Figure 1 where, COV (.) represents the covariance calculation. Stochastic processes that consider project correlation typically use Cholesky decomposition matrices. This decom- position method has a prerequisite in that any given matrix must be positive definite or positive semi-definite. Suppose that A is any nxn positive definite matrix (covariance or correlation matrix) and satisfies X' AX>0 for all nonzero eigenvectors X, where X'AX denotes a 1*1 matrix, namely, a real number. Cholesky decomposition can be used when the matrix is positive definite to decompose the matrix into a lower triangular matrix C and an upper triangular matrix C’ (A=CC"). The coefficients (a,;) in matrix A can then be obtained by solving n equations via back substitution, as follows.