In practical factorial experiments, we sometimes find that complete randomization of the order runs is infeasible because it more difficult to change levels some factors than others, especially in engineering experiments. Then, fractional split-plot (FFSP) designs represent a option such situations. The difficult-to-change are called whole plots (WP) factors, and other subplot (SP) factors. WP ...

PURPOSE Adaptive optics systems can be used to investigate the potential visual benefit associated with correcting ocular wave-front aberration. In this study, adaptive optics techniques were used to evaluate the potential advantages and disadvantages associated with intraocular lenses (IOLs) with modified spherical aberration profiles. METHODS An adaptive optics vision simulator was construc...

PURPOSE To use a large wave-front database of a clinical population to investigate relationships between refractions and higher-order aberrations and between aberrations of right and left eyes. METHODS Third- and fourth-order aberration coefficients and higher-order root-mean-squared aberrations (HO RMS), scaled to a pupil size of 4.5-mm diameter, were analyzed in a population of approximatel...

The coset pattern matrix (CPM) is formally defined as an elaborate characterization of the aliasing patterns of a fractional factorial design. The possibility of using CPM to check design isomorphism is investigated. Despite containing much information about effect aliasing, the CPM fails to determine a design uniquely. We report and discuss small nonisomorphic designs that have equivalent cose...

Factorial designs are arguably the most widely used designs in scientific investigations. Generalized minimum aberration (GMA) and uniformity are two important criteria for evaluating both regular and non-regular designs. The generation of GMA designs is a non-trivial problem due to the sequential optimization nature of the criterion. Based on an analytical expression between the generalized wo...

A compact vacuum ultraviolet spectrometer system has been developed to provide time-resolved impurity spectra from tokamak plasmas. Two interchangeable aberration-corrected toroidal diffraction gratings with flat focal fields provide simultaneous coverage over the ranges 100-1100 A or 160-1700 A. The detector is an intensified self-scanning photodiode array. Spectral resolution is 2 A with the ...

Specifying a prior distribution for the large number of parameters in the statistical model is a critical step in a Bayesian approach to the design and analysis of experiments. This article shows that the prior distribution can be induced from a functional prior on the underlying transfer function. The functional prior requires the specification of only a few hyper-parameters and therefore, can...

We present some optimal criteria to evaluate model-robustness of non-regular two-level fractional factorial designs. Our method is based on minimizing the sum of squares of all the off-diagonal elements in the information matrix, and considering expectation under appropriate distribution functions for unknown contamination of the interaction effects. By considering uniform distributions on symm...

Control of chromatic aberration through purely optical means is well known. We present a novel, to our knowledge, optical-digital method of controlling chromatic aberration. The optical-digital system, which incorporates a cubic phase-modulation (CPM) plate in the optical system and postprocessing of the detected image, effectively reduces a system's sensitivity to misfocus in general or axial ...