Vulnerability analysis of power grids using modified centrality measures

In the classical Hartmann test the wave front is obtained by integration of the transverse aberrations, joining the sampled points by small straight segments, in the so-called Newton integration. This integration is performed along straight lines joining the holes on the Hartmann screen. We propose a modification of this procedure, considering the cells of four holes of the Hartmann screen to fit a small second-power wave front recovering each square. This procedure has some important advantages, as described here. " 2005 Optical Society of America.",,,,,,"10.1364/AO.44.004228",,,"http://hdl.handle.net/20.500.12104/45716","http://www.scopus.com/inward/record.url?eid=2-s2.0-22944468778&partnerID=40&md5=f02049f689ac515188ee687ece73d18a",,,,,,"20",,"Applied Optics",,"422

Evaluation of error in the performance of power corrected ophthalmic lenses

In this work, we describe a new method for assessing the refractive correction error in power corrected ophthalmic lenses. The ideal power distribution map corresponding to the lens design to be measured is initially obtained. Then, using some known techniques, the real power distribution map of the lens under test is obtained. Finally, the difference between the two distributions is computed, obtaining a distribution map of the refractive correction error of the lens under analysis. In the paper, we describe the implementation of the proposed method using the Hartmann test to analyze a corrected power ophthalmic lens. The technique is analyzed, and its effects on measurement resolution discussed. This method can be useful to verify the designing errors in the lab or to verify manufacturing errors of ophthalmic lenses during mass production