基于小波变换的目标边缘搜索分割方法

为满足目标识别实时性、抗噪声的要求,提出了利用小波变换的图像边缘搜索分割方法.用反对称双正交小波算子对图像进行小波变换,对小波变换模极大值进行启发式搜索检测边缘,得到目标边缘的链码表示.该搜索方法能较好地克服噪声干扰,边缘丢失时能通过在模值分布图中搜索找回边缘,增强算法的鲁棒性.实验结果表明,在同样平台下,使用该方法检测边缘能减少一般小波多尺度分析的计算量,计算速度与使用Sobel算子的梯度方法相当,且具有更好的抗噪声能力.该方法边缘连接良好率高,特征提取方便,综合提高了图像处理算法效率.     

基于多尺度边缘响应函数的自适应阈值边缘检测算法

该文提出了一种基于多尺度边缘响应函数的自适应阈值边缘检测算法。首先分析二进小波变换,根据边缘和噪声随尺度变化的不同特性,设计了多尺度边缘响应函数(MERF)。通过MERF中的乘积放大作用,增大了边缘响应的幅度,同时也抑制了噪声产生的伪边缘。然后利用小波变换多尺度之间的联合分布关系,计算自适应阈值,检测MERF的梯度模值形成多尺度边缘。该算法直接在小波特征上进行多尺度合成,避免了多个边缘图合成过程的病态问题。实验表明,与LOG,Canny以及Mallat多尺度小波检测方法相比,该算法在检测和定位之间能够达到更好的平衡,既能够实现小尺度下的精确定位,也可以保留大尺度下对噪声的抑制作用。     

大鱼际掌纹图像边缘提取算法

主要研究大鱼际掌纹图像边缘提取算法。介绍几种经典的边缘检测算子以及Hough变换方法,重点讨论了小波模极大值多尺度边缘检测方法。构造了高斯多尺度边缘检测算子,根据噪声和图像边缘的小波变换模值跨尺度传递的不同特征,研究小波模极大值多尺度边缘检测方法,对大鱼际掌纹图像进行边缘提取。实验结果表明该方法检测到的边缘细节丰富,定位较准确,有效降低了噪声,不足之处是连续性较差。     

基于小波多尺度相关的特征边缘提取方法

根据采用小波变换提取图像边缘的多尺度特性,对小波多尺度间的相关性进行了分析,提出多尺度小波变换相关算子,分析了相关算子的滤波特性,利用相关算子对图像的多尺度边缘信息进行了优化.既保留了图像中重要的细节边缘信息,又剔除大量的冗余边缘和虚假边缘,有效地提取出了图像的特征边缘.     

基于小波多尺度分解的混沌时间序列消噪

本文基于小波多尺度分解的思想,提出了一种降低混沌序列噪声的方法。小波多尺度分解算法之所以能够区分不同尺度的信号,是因为它利用了小波变换在时、频两域具有突出信号局部特征的能力以及小波变换是线性变换的特点。鉴于实测的混沌信号的能量主要集中在低频,而具有突变特征的噪声的能量主要在高频部分,因而提出的方法仅需利用信号的尺度特性,就可以消除含噪混沌序列的大部分噪声。仿真实验给出了该算法的消噪性能分析,结论表明基于小波多尺度分解的混沌时间序列消噪具有良好的实用前景。     

基于小波的多尺度边缘检测在遥感图像处理中的应用

本文引入小波多尺度边缘检测,将小波的尺度因子与不同方向的梯度联系起来在梯度大的方向(垂直边缘方向)采用小尺度的因子,突出细节.在梯度小的方向(沿着边缘方向)采用大尺度因子,可提高信噪比.试验结果表明:该算法具有很好的边缘细节的保持性,较常见的P-M模型滤波方法算法效果有明显优势.     

基于信号奇异性分析的小目标检测方法

提出了一种新的基于信号奇异性分析的小目标检测方法,该方法将图像中的小目标看作是图像信号中的奇异点(突变点),利用小波变换模极大值点同信号奇异点之间的对应关系,结合信号奇异性与模极大值在多尺度上的变化规律,实现噪声抑制和信号增强,然后通过区域分析,检测图像小波变换模极大值,进而实现小目标检测。实验结果证明该方法是行之有效的。     

基于B样条小波多尺度积图像边缘提取技术

结合了B样条函数良好的逼近特性以及多尺度积算法的抗噪性能,来达到图像边缘检测的最佳效果。首先通过选择合适的小波滤波器对信号进行小波变换,之后通过相邻尺度的小波变换相乘得到尺度积,以检测出图像的模极大值,最后通过阈值滤掉伪边缘,得到图像的边缘信息。实验表明,该算法相比其他传统检测算子能有效地抑制图像噪声,并且图像边缘和细节信息的失真量小。     

基于小波变换的海面红外小目标检测

本文提出了一种基于小波多尺度分析的海面红外目标自动检测方法.在分析海空场景图像特征的基础上,利用小波多分辨率分析和小波变换良好的局部分析特性,研究了图像预处理和目标检测的小波分析方法.通过实验证明本文提出的检测算法在各种复杂的海空背景以及不同环境干扰下有较好的检测效果.     

基于Contourlet变换的红外图像序列小目标检测技术

Contourlet变换具有多尺度,多方向性的特征,是小波的一种扩展.本文提出了一种基于Contourlet变换的红外小目标检测算法.首先对图像进行Contourlet分解;然后利用能量法提取其局部纹理特征,并计算各点的特征向量与中心向量问的距离,得到一个相关的多尺度距离像;最后根据该距离像进行直方图统计,从而实现目标的检测.文中给出了实验结果,并与基于小波变换的红外小目标检测算法进行了比较,结果表明,本方法能较精确地检测出红外小目标,优于基于小波变换的方法.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-