In this paper, a three ring-resonator serially coupled is considered as an optical filter. We are going to improve the performance of the designed optical filter by increasing the quality factor and finesse of filtered wavelengths. The first and last rings are coupled to the bus waveguides that carry the input and output fields. The effect of coupling parameters and ring radii on the filtering ...

In this paper, we address the problem of ill-conditioning Wiener filter, optimal linear minimum mean square error estimator. Computing filter involves inverse observation covariance matrix. practice, matrix has a large condition number, resulting in unreliable numerical computation filter. To issue, develop four approximate formulas using truncation technique based on principal components compo...

Introduction Vessel enhancement filters applied to 3D MRA data sets prior to rendering as a 2D image may improve visualization of vessel detail. We previously compared several line enhancement filters for intracranial 3D MR angiography images[1]. We examined filters based on discrete lines (e.g., Du and Parker's filter [2]) and on the Hessian matrix (Frangi [3]). We found the Du and Parker filt...

Kalman filter is one of the most common ways to deal with dynamic data and has been widely used in project fields. However, the accuracy of Kalman filter for discrete dynamic system is poor when the observation matrix is ill-conditioned. Therefore, the method for overcoming the harmful effect caused by ill-conditioned observation matrix in discrete dynamic system is studied in this paper. First...

In this paper the standard variational analysis scheme is modified, through a simple transform, to avoid the inversion of the background error covariance matrix. A close inspection of the modified scheme reveals that it is possible to use a filter to replace the multiplication of the covariance matrix. A variational analysis scheme using a filter is then formulated, which does not explicitly in...