A novel joint diagonalization fractional lower-order spatio-temporal (ST) moments DOA matrix method is proposed to estimate the 2-D DOAs of uncorrelated nar-rowband signals in the presence of impulsive noise. The new ...A novel joint diagonalization fractional lower-order spatio-temporal (ST) moments DOA matrix method is proposed to estimate the 2-D DOAs of uncorrelated nar-rowband signals in the presence of impulsive noise. The new method retains the advantage of the original ST-DOA matrix method which can estimate 2-D DOAs with neither peak searching nor pair matching. Moreover,it can handle sources with common 1-D angles. Simulation results show that the proposed method yields to better performance to restrain the strong impulsive noise than ST-DOA matrix method,especially for low signal-to-noise ratio case.展开更多
AIM:To evaluate the efficacy of custom-made soft keratoconus(KC)lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.METHODS:Sixty eyes of 42 patients with KC were exam...AIM:To evaluate the efficacy of custom-made soft keratoconus(KC)lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.METHODS:Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone(Toris K)soft silicone hydrogel lenses.Best spectacle-corrected visual acuity(BSCVA)and contact lens-corrected visual acuity(CLCVA)were recorded.Lower-and higher-order corneal aberrations(LOAs and HOAs)were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones.Mesopic pupil diameter and subjective photic phenomena were also assessed.RESULTS:Mean CLCVA was significantly improved compared to BSCVA(P<0.0001).Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses,except for posterior corneal curvature values.In the 4.5 mm central optical zone,all wavefront aberrations decreased significantly after lens fitting(P<0.0001).In contrast,in the 7 mm(peripheral)optical zone,values for HOAs,spherical and residual aberrations,and optical path differences were increased,while LOAs,trefoil,and quadrifoil coefficients were decreased.The rate of photic phenomena was significantly higher in participants with a pupil size>6.00 mm(85.7%).CONCLUSION:Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations.This practical and nonsurgical approach appears to be an effective method for the visual management of KC.展开更多
Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attracti...Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.展开更多
基金the National Natural Science Foundation of China (Grant No.60372022)Program for New Century Excellent Talents in University (Grant No.NCET-05-0806)
文摘A novel joint diagonalization fractional lower-order spatio-temporal (ST) moments DOA matrix method is proposed to estimate the 2-D DOAs of uncorrelated nar-rowband signals in the presence of impulsive noise. The new method retains the advantage of the original ST-DOA matrix method which can estimate 2-D DOAs with neither peak searching nor pair matching. Moreover,it can handle sources with common 1-D angles. Simulation results show that the proposed method yields to better performance to restrain the strong impulsive noise than ST-DOA matrix method,especially for low signal-to-noise ratio case.
文摘AIM:To evaluate the efficacy of custom-made soft keratoconus(KC)lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.METHODS:Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone(Toris K)soft silicone hydrogel lenses.Best spectacle-corrected visual acuity(BSCVA)and contact lens-corrected visual acuity(CLCVA)were recorded.Lower-and higher-order corneal aberrations(LOAs and HOAs)were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones.Mesopic pupil diameter and subjective photic phenomena were also assessed.RESULTS:Mean CLCVA was significantly improved compared to BSCVA(P<0.0001).Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses,except for posterior corneal curvature values.In the 4.5 mm central optical zone,all wavefront aberrations decreased significantly after lens fitting(P<0.0001).In contrast,in the 7 mm(peripheral)optical zone,values for HOAs,spherical and residual aberrations,and optical path differences were increased,while LOAs,trefoil,and quadrifoil coefficients were decreased.The rate of photic phenomena was significantly higher in participants with a pupil size>6.00 mm(85.7%).CONCLUSION:Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations.This practical and nonsurgical approach appears to be an effective method for the visual management of KC.
文摘Fractional factorial split-plot design has been widely used in many fields due to its advantage of saving experimental cost. The general minimum lower order confounding criterion is usually used as one of the attractive design criterion for selecting fractional factorial split-plot design. In this paper, we are interested in the theoretical construction methods of the optimal fractional factorial split-plot designs under the general minimum lower order confounding criterion. We present the theoretical construction methods of optimal fractional factorial split-plot designs under general minimum lower order confounding criterion under several conditions.
