Abstract:

Abstract:Rigorous analysis of discontinuities in planar transmission lines may require accurate computation of a large number of modes. An improved formulation of the singular integral equation (SIE) method for multilayer unilateral finlines was presented to address this problem. All the series truncated possess the fast convergence property. A systematic approach for analytical calculation of the characteristic matrix to arbitrary order was also proposed. For the determination of propagation constants, an analytical function that eliminates all the poles in the determinant of the characteristic matrix was constructed. The developed numerical techniques lead to an accurate, efficient, and reliable computation of both propagation constants and field distributions for a large number of modes.

Abstract:The photoluminescence(PL) properties of nitrogen doped ZnSe epilayers grown on semi insulating GaAs(100) substrates by MBE using a rf plasma source for N doping were investigated. The PL peak which can be related to N acceptor was observed in the PL spectra of ZnSe:N smaples. At 10K, as the excitation power density increases, the energy of donor acceptor pair(DAP) emission shows a blue shift and its intensity tends to saturate. As the temperature increases over a range from 10K to 300K, the relative PL intensity of donor bound exciton to that of the acceptor bound exciton increases due to the transfer between two bound excitons.

Abstract:The electrical property of boron implantation of MBE grown HgCdTe and the profile of carrier concentration and mobility measured by sheet Hall were presented. After etching the epilayer to p n junction position, the transmittance of this position was raised, which was ascribed to the high transmission of junction region.

Abstract:报道了采用红外椭圆偏振光谱术测量ＧａＡｓ体材料折射率，测量范围为２．５～１２．５μｍ，并将所得实验数据与理论计算和其它实验结果进行了对比，表明了实验结果的可靠性．

Abstract:在ｎ－ＧａＰ衬底上制作共面波导（ＣＰＷ），用质子轰击的方法减小共面波导的漏电损失，用倍频扫描移相电光采样技术测量了１～５ＧＨｚ微波信号．质子轰击后ＧａＰＣＰＷ的电阻增大了４个量级，在２．３０ＧＨｚ微波信号时，质子轰击ＧａＰＣＰＷ电光采样测量获得了１０ｍＶ／Ｈｚ的电压灵敏度．

Abstract:介绍了由４×４元Ｓｉ光伏探测器及１６路小型前置放大器组成的探测器前放集成组件，详细分析了各元件对电路的增益、频响、噪声、温度漂移等特性的影响，提出了优化设计准则，并进行了电磁兼容设计．

Abstract:在考虑器件自热效应的情况下，对微测辐射热计的性能进行了深入地理论分析，应用了微测辐射热计的有效热导Ｇｅｆｆ概念，得出对于一定的热导的器件，存在着最佳工作偏置电流Ｉ０ｏｐｔ这一重要结论，并找到一种通过电学测量确定微测辐射热计有效热导Ｇｅｆｆ和有效时间常数τｅｆｆ的方法．试验结果与理论分析符合．

Abstract:介绍了相关双采样法（ＣＤＳ）、四δ采样、差分平均法等方法对像元复位噪声（ＫＴＣ）的抑制作用，从理论上分析了这几种方法对输入噪声的影响．将这几种方法用于线列红外焦平面，并对不同方法对噪声改善的程度进行了实验比较．

Abstract:The principle and experiment study on two color false CLLL TV system were carried out. Two color detection technology, the best matching color filtering technology and false color technology trying to display natural color of the scene in daylight were studied in depth. Results show that through the fusion of infrared and low light level images, the image resolution and the probability by which the scene objects were discovered and discriminated by human eyes can be increased significantly.

Abstract:提出一种将新颖的眼睑弹性模板与霍夫变换相结合实现眼睛特征的自动提取的方法，即自动定位眼球并自动提取眼睛轮廓，与其它用弹性模板提取眼睛特征的方法相比，本方法可以处理对比度较低、下眼睑模糊的图像，提取特征准确度更高，且改进的能量函数和保守能量下降算法大大简化了经验参数的选择，经过百余幅眼睛图像的实验处理，验证了该方法的有效性。

Abstract:To alleviate the influence of the unstability of extracting some feature points caused by affine transforms, new affine invariants for target recognition were proposed, which are based on feature points and the boundary that is almost unaffected by affine transforms. New invariants depend on the current feature point and the whole boundary when the target is not occluded and on the current feature point, two directly neighboring ones and the boundary between them when the target is occluded. New invariants depend on the least feature points among the affine invariants based on feature points, which helps to apply them to the situation that the extraction of feature points is unstable.

Abstract:The iterative formulas of Fuzzy C Means algorithm in feature space were deduced before two methods were presented to improve the distribution property of membership information. The first was to control the distribution of membership information by introducting selective attention parameters. The other was to construct cluster fiducial values from the point of probability to replace original membership information. Results of the experiments confirm the effectiveness of the two methods.

Abstract:Based on its characteristics, the remote sensing image was enhanced on its fuzzy property domain, then the threshold was selected by use of the entropy concept in gray image. Finally, a comparision with two other threshold selection methods was investigated quantitatively and qualitatively. The experimental results show that this method can segment the object from background precisely and quickly.

Abstract:An image segmentation scheme was presented on the basis of locally excitatory, globally inhibitory oscillator network (LEGION). Based on the concept of the lateral potential, a solution to remove noisy regions in an image was proposed for LEGION. The temporal evolution of every stimulated oscilltor and network properties were illustrated by computer simulation. The dynamic connection weight addressing the grouping principles of proximity, similarity and connectedness was setup. Using HSI space, the dynamic connection weight emphasizing the Hue information was established, and better experimental results than that based on RGB space were obtained.

Abstract:A new dissociating unifying image segmentation method was presented, which firstly over segments an image using pyramid fuzzy C mean(PFCM) clustering, then unifyes these over segmented regions into some significant object regions by using fuzzy mergence technique. Finally. several typical experiments to verify the proposed method were given with satisfactory results.

Abstract:给出一种新的通过空间热梯度辅助的热调制反射光谱方法，其关键是在空间光谱方法基础上加一热场梯度，无需对材料进行通常空间调制方法的特殊处理．将该方法应用于典型半导体材料ＧａＡｓ，清晰地观察到ＧａＡｓ材料的带间跃迁Ｅ０和其它诸如Ｅ０＋Δ０、Ｅ１、Ｅ１＋Δ１的高能带跃迁．