高分辨率遥感图像中的细小目标(如道路等)使图像的同类区域表现变得不一致,从而增加了高分辨率图像聚类的难度,本文提出了一种高分辨率遥感图像的聚类方法,其聚类过程包括如下三个步骤:第一步,在滑动窗口内使用消除次要成分法处理遥感图...高分辨率遥感图像中的细小目标(如道路等)使图像的同类区域表现变得不一致,从而增加了高分辨率图像聚类的难度,本文提出了一种高分辨率遥感图像的聚类方法,其聚类过程包括如下三个步骤:第一步,在滑动窗口内使用消除次要成分法处理遥感图像,该处理过程使用一维形态学分水岭技术获得直方图中的左侧阈值和右侧阈值,再根据这两个阈值滤除图像中的次要成分;第二步,计算滑动窗口内的图像特征;第三步根据图像特征量利用BPC(Back Propagation and Competitive)网络进行图像聚类。三组试验(本文提出的聚类算法,最邻近距离聚类法,K均值聚类法)表明本文提出的图像聚类方法可以有效实现高分辨率遥感图像的聚类。展开更多
The description and function characterization of a flange-on type low energy electron mi- croscope are given. In this microscope a magnetic beam separator with 10° deflection angle is used in order to facilitate ...The description and function characterization of a flange-on type low energy electron mi- croscope are given. In this microscope a magnetic beam separator with 10° deflection angle is used in order to facilitate compacting the instrument on a single 10 in. flange. Mean- while some correcting elements in the electron optical system are simplified to reduce the complexities of construction and operation. The sample is set close to ground potential, so that all the electrostatic lenses are easily to float at high voltages. The performance of the microscope in typical low energy electron microscopy, low energy electron diffraction and photoemission electron microscopy modes is demonstrated through several experiments. A lateral resolution of 51 nm is estimated for low energy electron microscopy imaging. With femtosecond laser as light source, the consequent nonlinear photoemission makes this micro-scope also suitable for the observation of optical near field phenomena and a lateral resolution of 110 nm is obtained.展开更多
A low-power 14-bit 150MS/s an- alog-to-digital converter （ADC） is present- ed for communication applications. Range scaling enables a maximal 2-Vp-p input with a single-stage opamp adopted. Opamp and capacitor shari...A low-power 14-bit 150MS/s an- alog-to-digital converter （ADC） is present- ed for communication applications. Range scaling enables a maximal 2-Vp-p input with a single-stage opamp adopted. Opamp and capacitor sharing between the first multi- plying digital-to-analog converter （MDAC） and the second one reduces the total opamp power further. The dedicated sample-and- hold amplifier （SHA） is removed to lower the power and the noise. The blind calibration of linearity errors is proposed to improve the per- formance. The prototype ADC is fabricated in a 130rim CMOS process with a 1.3-V supply voltage. The SNDR of the ADC is 71.3 dB with a 2.4 MHz input and remains 68.5 dB for a 120 MHz input. It consumes 85 roW, which includes 57 mW for the ADC core, 11 mW for the low jitter clock receiver and 17 mW for the high-speed reference buffer.展开更多
The mixture of factor analyzers （MFA） can accurately describe high resolution range profile （HRRP） statistical charac- teristics. But how to determine the proper number of the models is a problem. This paper devel...The mixture of factor analyzers （MFA） can accurately describe high resolution range profile （HRRP） statistical charac- teristics. But how to determine the proper number of the models is a problem. This paper develops a variational Bayesian mixture of factor analyzers （VBMFA） model. This procedure can obtain a lower bound on the Bayesian integral using the Jensen＇s inequality. An analytical solution of the Bayesian integral could be obtained by a hypothesis that latent variables in the model are indepen- dent. During computing the parameters of the model, birth-death moves are utilized to determine the optimal number of model au- tomatically. Experimental results for measured data show that the VBMFA method has better recognition performance than FA and MFA method.展开更多
文摘高分辨率遥感图像中的细小目标(如道路等)使图像的同类区域表现变得不一致,从而增加了高分辨率图像聚类的难度,本文提出了一种高分辨率遥感图像的聚类方法,其聚类过程包括如下三个步骤:第一步,在滑动窗口内使用消除次要成分法处理遥感图像,该处理过程使用一维形态学分水岭技术获得直方图中的左侧阈值和右侧阈值,再根据这两个阈值滤除图像中的次要成分;第二步,计算滑动窗口内的图像特征;第三步根据图像特征量利用BPC(Back Propagation and Competitive)网络进行图像聚类。三组试验(本文提出的聚类算法,最邻近距离聚类法,K均值聚类法)表明本文提出的图像聚类方法可以有效实现高分辨率遥感图像的聚类。
文摘The description and function characterization of a flange-on type low energy electron mi- croscope are given. In this microscope a magnetic beam separator with 10° deflection angle is used in order to facilitate compacting the instrument on a single 10 in. flange. Mean- while some correcting elements in the electron optical system are simplified to reduce the complexities of construction and operation. The sample is set close to ground potential, so that all the electrostatic lenses are easily to float at high voltages. The performance of the microscope in typical low energy electron microscopy, low energy electron diffraction and photoemission electron microscopy modes is demonstrated through several experiments. A lateral resolution of 51 nm is estimated for low energy electron microscopy imaging. With femtosecond laser as light source, the consequent nonlinear photoemission makes this micro-scope also suitable for the observation of optical near field phenomena and a lateral resolution of 110 nm is obtained.
基金supported by the Major National Science & Technology Program of China under Grant No.2012ZX03004004-002National High Technology Research and Development Program of China under Grant No. 2013AA014302
文摘A low-power 14-bit 150MS/s an- alog-to-digital converter （ADC） is present- ed for communication applications. Range scaling enables a maximal 2-Vp-p input with a single-stage opamp adopted. Opamp and capacitor sharing between the first multi- plying digital-to-analog converter （MDAC） and the second one reduces the total opamp power further. The dedicated sample-and- hold amplifier （SHA） is removed to lower the power and the noise. The blind calibration of linearity errors is proposed to improve the per- formance. The prototype ADC is fabricated in a 130rim CMOS process with a 1.3-V supply voltage. The SNDR of the ADC is 71.3 dB with a 2.4 MHz input and remains 68.5 dB for a 120 MHz input. It consumes 85 roW, which includes 57 mW for the ADC core, 11 mW for the low jitter clock receiver and 17 mW for the high-speed reference buffer.
基金supported in part by the National Natural Science Foundation of China(60772140)the Program for Cheung Kong Scholarsand Innovative Research Team in University(IRT0645)
文摘The mixture of factor analyzers （MFA） can accurately describe high resolution range profile （HRRP） statistical charac- teristics. But how to determine the proper number of the models is a problem. This paper develops a variational Bayesian mixture of factor analyzers （VBMFA） model. This procedure can obtain a lower bound on the Bayesian integral using the Jensen＇s inequality. An analytical solution of the Bayesian integral could be obtained by a hypothesis that latent variables in the model are indepen- dent. During computing the parameters of the model, birth-death moves are utilized to determine the optimal number of model au- tomatically. Experimental results for measured data show that the VBMFA method has better recognition performance than FA and MFA method.
