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Unformatted text preview: nts cw and cwr, the frequency spectrum of the waviness and/or roughness variation, and the polynomial coefficient matrix of the warping variation. The hybrid method is carried out according to the following steps: 1. Model the geometric covariance of the waviness and roughness variation using the frequency spectrum method. Inputs: frequency spectrum 2. Model the geometric covariance of the warping variation using the orthogonal polynomial method. Inputs: polynomial coefficient vector 3. Combine the two covariances according to Eq. (8) to model the total covariance. Inputs: cw and cwr To develop the descriptors for the hybrid model, typical variation from a manufacturing process is required. The descriptors are obtained by first obtaining the warping portion of the variation data by fitting and subtracting successive polynomials; the remaining variation is the waviness and roughness portion. The warping variation and the waviness and roughness variation are then normalized such that their average values ha...
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- Spring '10
- The Land