基于多尺度对比度塔和方向滤波器组的图像融合

本文从图像的特性出发,将方向信息与多分辨分析相结合,提出了基于方向滤波器组的融合思想.进而考虑到人眼的视觉特性,利用对比度塔分解(CP)捕获图像的低频分量,利用方向滤波器组(DFB)获得图像的高频分量,提出了一种基于多尺度对比度塔和方向滤波器组(CPDFB)的图像融合方法,同时分析了该方法的融合机理和计算复杂度,较好地实现了复杂图像的融合.仿真实验验证了其可行性和有效性.     

基于视觉特性的多聚焦图像融合

本文提出了一种考虑人眼视觉系统特性的多聚焦图像融合算法.融合过程是首先将配准的源图像分割成若干个块,计算出每个块的对比度方差,作为图像均匀度参数,通过选取两幅图像中清晰的图像块形成融合图像.文中讨论了分解图像块的大小和阈值参数对融合性能的影响.实验结果表明本文提出的算法实时性好,对于严格配准的多聚焦图像能够达到甚至超过基于小波分解的融合算法.     

基于视觉显著性与对比度增强的红外图像融合

目前传统多尺度分析红外图像融合算法存在以下不足:融合图像的对比度改善效果有限,无法获取图像的某些细节信息;融合规则仅考虑单一特征,故未能突出目标特征。针对以上问题,本文提出一种基于视觉显著性与对比度增强的红外图像融合算法。首先对待融合的图像进行基于自适应引导滤波的多尺度Retinex图像增强,然后利用NSCT对图像进行多尺度分解,最后利用图像视觉显著性融合低频系数,采用基于窗口的系数融合带通系数。实验证明,该算法获得的红外融合图像效果明显优于传统方法。     

基于对比度的多分辨图像融合

本文给出一种基于对比度的多分辨图像融合算法.首先,利用小波变换得到待融合图像的多分辨分析,同时得到图像的多分辨对比度序列;然后以对比度为判据,在图像的多分辨分析的相应各级上进行融合,得到融合图像的多分辨分析;最后,利用小波逆变换重构融合图像.算法使用同一场景可见光图像和红外图像进行了验证,结果表明,融合图像完好地显示了源图像各自的信息.     

基于双树复小波变换的多聚焦图像融合方法

针对同一场景的多聚焦图像融合,提出了一种基于双树复小波变换(DT-CWT)的图像融合新算法.首先利用DT-CWT对图像进行多尺度和多方向分解,并根据双树复小波分解域各子带的系数特性定义了图像局部方向对比度,然后针对高频分量系数的选择,采用基于方向对比度的融合规则,而在低频域采用图像清晰度为测度的融合策略.实验结果表明,该算法能够很好地将多聚焦图像中的重要信息提取并注入到融合图像中,与其他方法相比较,取得了更好的融合效果,提高了融合图像的质量.     

利用量化判据进行多聚焦融合图像的重构分析

提出一种基于对比度视觉模型的图像融合自适应分块搜索算法,利用几种量化判据,即均方根误差、熵、交叉熵和互信息进行融合图像序列分析及效果评价,对同一场景两幅严格配准的多聚焦图像的清晰恢复进行了深入研究。通过大量的图像实验表明:无论是依据视觉的主观评价,还是客观评价准则,该方法能实现多聚焦图像对标准参考图像的精确重构或优化融合效果。     

基于边缘强度匹配的图像融合并行算法的研究

图像融合是图像理解和计算机视觉领域中的一项重要课题。随着图像规模的增大,图像融合面临着处理速度的挑战。最近几年,GPU面向通用计算应用得到了快速发展。本文基于GPU编程模型和硬件特性,深入研究了基于边缘强度的图像融合算法,提出了该算法的并行模型。实验结果表明,该方法有效地综合了源图像中的重要信息,融合图像边界清晰,得到较好视觉效果和较优的评价指标,执行速度与CPU上相比提高了3个数量级。     

基于视觉特性的非线性多尺度彩色图像增强

[目的]针对图像在低光照下的亮度和对比度偏低的问题,提出一种基于视觉特性的非线性多尺度彩色图像增强算法.[方法]该算法将彩色图像从RGB色彩空间转化到HSI色彩空间,保持H分量不变,对S分量进行指数拉伸,对Ⅰ分量利用视觉系统模型和非线性映射方法实现图像对比度增强,再通过自适应的亮度调整增加图像的全局亮度.最后将HSI色彩空间转化到RGB色彩空间,从而实现对彩色图像自适应增强.[结果]通过对低光照彩色图像进行增强测试,其测试结果表明,[结论]该算法能够自适应地调整图像的全局亮度,增加图像的局部细节对比度,并保持其原色彩,提升彩色图像在低光照下的视见度.     

基于小波变换和视觉特性的多光谱图像融合

本文提出了一种基于小波变换和人眼视觉系统特性的多光谱图像融合算法。首先对已配准的源图像进行小波多尺度分解;其次基于视觉系统提出一种新的融合规则,即分别将对应的高低频分量分割成若干个块,计算出每个块的对比度方差,通过文中所构造的一种自适应的阈值方法,选取两幅图像中清晰的图像块形成新的高低频分量;最后,通过小波反演变换重构多光谱图像。实验结果表明,这种方法不仅能很好的增强多光谱图像的空间细节能力及光谱信息,而且能避免增强结果出现振铃效应,是一种十分有效的融合方法。     

基于IMOPSO算法的多目标多聚焦图像融合

目前的多聚焦图像融合方法对于融合模型的建立主要依赖于经验,其参数配置存在主观性.提出了一种基于IMOPSO算法的多目标多聚焦图像融合方法,简化了多聚焦图像融合模型,克服了参数配置对经验的依赖性.首先给出了多聚焦图像融合有效的评价指标,然后构造了统一的小波域多聚焦图像融合模型,最后以模型参数作为决策变量,采用IMOPSO算法进行多目标优化搜索.IMOPSO算法不但引入变异算子以避免早熟,而且引入拥挤算子,使Pareto优解尽可能均匀分布于Pareto前端,并采用一种新的自适应惯性权重提高寻优能力.实验结果表明,IMOPSO算法具有更快的收敛速度和更好的寻优能力,同时基于该算法的融合方法也实现了Pareto最优多聚焦图像融合.     

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-