目的:研究视网膜神经纤维层及黄斑厚度不对称参数在原发性开角型青光眼(primary open angle glaucoma,POAG)早期诊断中的应用。方法:临床研究对象包括正常受试者50例100眼和单侧早期POAG的患者50例100眼,使用Humphrey视野计记录视野平...目的:研究视网膜神经纤维层及黄斑厚度不对称参数在原发性开角型青光眼(primary open angle glaucoma,POAG)早期诊断中的应用。方法:临床研究对象包括正常受试者50例100眼和单侧早期POAG的患者50例100眼,使用Humphrey视野计记录视野平均缺损(MD)和模式标准差(PSD)、Cirrus HDOCT、扫描视网膜神经纤维层(RNFL)厚度、黄斑厚度,并进行后极部不对称参数分析,后者主要为双眼RNFL厚度及黄斑厚度的比较、眼内上/下方RNFL厚度的比较,眼内上/下方黄斑厚度的比较,并计算所有OCT、参数的曲线下面积(AUC)。结果:除眼内上/下方视盘RNFL厚度差值比较无统计学意义(P=0.265),两组研究对象视盘RNFL厚度、黄斑厚度、双眼上方/下方/总体RNFL厚度或黄斑厚度的不对称性差异、眼内上/下方黄斑厚度的差值均有统计学意义(P<0.05)。视盘RNFL总体厚度的AUC值为0.827。视盘RNFL总体厚度差值的敏感性最高,95%特异性的敏感度为67%。黄斑总体厚度平均值的AUC值为0.822。黄斑厚度差值的AUC值为0.777。结论:后极部视网膜厚度不对称参数分析对早期POAG患者提供了良好的诊断效能,且与RNFL厚度的诊断精度相似。然而,眼内不对称分析参数表现不佳,需要在其用于早期单侧青光眼诊断之前进一步细化。展开更多
The symmetries of the （2＋1）-dimensional nonlinear incompressible non-hydrostatic Boussinesq （INHB） equations, which describe the atmospheric gravity waves （GWs）, are researched in this paper. The Lie symmetries...The symmetries of the （2＋1）-dimensional nonlinear incompressible non-hydrostatic Boussinesq （INHB） equations, which describe the atmospheric gravity waves （GWs）, are researched in this paper. The Lie symmetries and the corresponding reductions are obtained by means of classical Lie group approach. Calculation shows the INHB equations are invariant under some Galilean transformations, scaling transformations, and space-time translations. The symmetry reduction equations and similar solutions of the INHB equations are proposed.展开更多
The variation of the vibration characteristics of a Huanghua pear was investigated using finite element simulations. A new image processing technique was used to obtain the unsymmetrical and un-spherical geometrical m...The variation of the vibration characteristics of a Huanghua pear was investigated using finite element simulations. A new image processing technique was used to obtain the unsymmetrical and un-spherical geometrical model of a pear. The vibra-tion characteristics of this type of pear with the correlation of its behavior with geometrical configurations and material charac-teristics were investigated using numerical modal analysis. The results showed that the eigenfrequency increased with the in-creasing pear Young’s modulus, while decreased with increasing pear density, and decreased with increasing pear volume. The results of this study provided foundation for further investigations of the physical characteristics of fruits and vegetables by using finite element simulations.展开更多
The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDB...The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDBD has been dedicated to planar frames, but recently also some proposals for 3D structures have been presented, in particular for wall structures. This paper will give a further contribution to the extension of the procedure for the case of plan-asymmetric RC （reinforced concrete） frames. The extended methodology is aimed at accounting for the floor rotations on the basis of a given lateral strength distribution along the plan. The procedure was applied to two plan-asymmetric RC frames, characterized by the same geometry but different lateral strength distributions along the plan. The seismic behavior of the designed frames was studied by adopting a fiber model and by performing pushover and nonlinear dynamic analyses.展开更多
The performances of selection cooperation are investigated over asymmetric fading channels where the source-relay and the relay-destination channels experience Nakagami-m and Rayleigh fading,respectively.Decode-and-fo...The performances of selection cooperation are investigated over asymmetric fading channels where the source-relay and the relay-destination channels experience Nakagami-m and Rayleigh fading,respectively.Decode-and-forward(DF)protocol is adopted and the Nth best relay is selected from M available relays.Probability density function(PDF)for the instantaneous signal-to-noise ratio(SNR)at the destination is derived first.Then,it is used to derive the exact expressions for outage probability and average symbol error rate(SER).The results hold for arbitrary M or N.Finally,simulations are carried out to verify the correctness of our theoretical analysis and results show that M and N almost have the same effect on the performance of outage probability and SER.展开更多
文摘目的:研究视网膜神经纤维层及黄斑厚度不对称参数在原发性开角型青光眼(primary open angle glaucoma,POAG)早期诊断中的应用。方法:临床研究对象包括正常受试者50例100眼和单侧早期POAG的患者50例100眼,使用Humphrey视野计记录视野平均缺损(MD)和模式标准差(PSD)、Cirrus HDOCT、扫描视网膜神经纤维层(RNFL)厚度、黄斑厚度,并进行后极部不对称参数分析,后者主要为双眼RNFL厚度及黄斑厚度的比较、眼内上/下方RNFL厚度的比较,眼内上/下方黄斑厚度的比较,并计算所有OCT、参数的曲线下面积(AUC)。结果:除眼内上/下方视盘RNFL厚度差值比较无统计学意义(P=0.265),两组研究对象视盘RNFL厚度、黄斑厚度、双眼上方/下方/总体RNFL厚度或黄斑厚度的不对称性差异、眼内上/下方黄斑厚度的差值均有统计学意义(P<0.05)。视盘RNFL总体厚度的AUC值为0.827。视盘RNFL总体厚度差值的敏感性最高,95%特异性的敏感度为67%。黄斑总体厚度平均值的AUC值为0.822。黄斑厚度差值的AUC值为0.777。结论:后极部视网膜厚度不对称参数分析对早期POAG患者提供了良好的诊断效能,且与RNFL厚度的诊断精度相似。然而,眼内不对称分析参数表现不佳,需要在其用于早期单侧青光眼诊断之前进一步细化。
基金Supported by the Scientific Research Foundation for the Doctors of University of Electronic Science and Technology of China Zhongshan Institute under Grant No. 408YKQ09the National Natural Science Foundation of China under Grant No. 10735030
文摘The symmetries of the （2＋1）-dimensional nonlinear incompressible non-hydrostatic Boussinesq （INHB） equations, which describe the atmospheric gravity waves （GWs）, are researched in this paper. The Lie symmetries and the corresponding reductions are obtained by means of classical Lie group approach. Calculation shows the INHB equations are invariant under some Galilean transformations, scaling transformations, and space-time translations. The symmetry reduction equations and similar solutions of the INHB equations are proposed.
基金Project (No. 30170533) supported by the National Natural ScienceFoundation of China
文摘The variation of the vibration characteristics of a Huanghua pear was investigated using finite element simulations. A new image processing technique was used to obtain the unsymmetrical and un-spherical geometrical model of a pear. The vibra-tion characteristics of this type of pear with the correlation of its behavior with geometrical configurations and material charac-teristics were investigated using numerical modal analysis. The results showed that the eigenfrequency increased with the in-creasing pear Young’s modulus, while decreased with increasing pear density, and decreased with increasing pear volume. The results of this study provided foundation for further investigations of the physical characteristics of fruits and vegetables by using finite element simulations.
文摘The object of this paper is the evaluation of the seismic response of reinforced concrete frames designed according to the DDBD （direct displacement-based design） approach. The great part of research works about DDBD has been dedicated to planar frames, but recently also some proposals for 3D structures have been presented, in particular for wall structures. This paper will give a further contribution to the extension of the procedure for the case of plan-asymmetric RC （reinforced concrete） frames. The extended methodology is aimed at accounting for the floor rotations on the basis of a given lateral strength distribution along the plan. The procedure was applied to two plan-asymmetric RC frames, characterized by the same geometry but different lateral strength distributions along the plan. The seismic behavior of the designed frames was studied by adopting a fiber model and by performing pushover and nonlinear dynamic analyses.
基金Supported by the National Natural Science Foundation of China(No.6087024)the Cultivation Fund of the Key Scientific and Technical Innovation Project(No.708059)+2 种基金Open Found of State Key Laboratory of Integrated Services Networks(No.ISN12-10)Open Research Fund of National Mobile Communications Research Laboratory(No.2012D10)the Natural Science Foundation of Shandong Province(No.ZR2011FM027)
文摘The performances of selection cooperation are investigated over asymmetric fading channels where the source-relay and the relay-destination channels experience Nakagami-m and Rayleigh fading,respectively.Decode-and-forward(DF)protocol is adopted and the Nth best relay is selected from M available relays.Probability density function(PDF)for the instantaneous signal-to-noise ratio(SNR)at the destination is derived first.Then,it is used to derive the exact expressions for outage probability and average symbol error rate(SER).The results hold for arbitrary M or N.Finally,simulations are carried out to verify the correctness of our theoretical analysis and results show that M and N almost have the same effect on the performance of outage probability and SER.
