区域指导的自适应图像插值算法

提出了一种以图像区域的一致性为指导的自适应选择插值公式(简称ADA)的图像插值算法.首先将图像分割成不同区域,然后结合近邻法和众数法确定待插值点所属区域,将待插值点分类处理:对于区域内的点,采用线性插值;对于区域间的过渡点,设计非线性插值公式,分配较大的权值给与待插值点属于同一区域的邻域像素,分配较小的权值给其它邻域像素.实验表明,ADA图像插值算法得到的插值图像有较好的主观图像质量,其峰值信噪比(PSNR)比传统方法平均提高了3.11～4.39 dB.     

基于多尺度局部方差的海面红外舰船检测

方差可以表示局部区域中各像素之间的关系：一般情况下,不同的像素相同的邻域大小计算出的方差不同,相同的像素不同的邻域大小计算出的方差也不同。本文构造多尺度局部方差,来计算每个像素的方差随尺度变化的情况。目标像素与其邻域像素的方差随尺度变化大,背景像素与其邻域像素的方差随尺度变化小;最后运用行列投影求出方差变化大的像素作为检测结果。实验结果表明,本文算法可以有效减弱背景中各种干扰的影响,正确检测出红外图像中舰船目标的位置。     

基于波段分组的高光谱图像无损压缩

高光谱图像海量数据给存储和传输带来极大困难,必须对其进行有效压缩。针对高光谱图像不同频谱波段间相关性不同的特点,提出一种基于波段分组的高光谱图像无损压缩算法。为了降低波段排序算法的计算量,根据相邻波段相关性大小预先进行分组,采用最佳后向排序算法对各组波段进行重新排序。在当前波段和参考波段中选取具有相同空间位置的邻域结构,在最小二乘准则下,利用邻域像素对当前预测像素进行最优谱间预测。参考波段和预测残差数据进行JPEG-LS压缩。对OMIS-I型高光谱图像进行实验的结果表明,与基于多波段预测算法相比,该算法可进一步降低压缩后的平均比特率。     

基于区域分割和非采样Contourlet变换的红外和可见光图像融合

针对同一场景的红外和可见光图像，提出一种基于OTSU递归分割算法的区域分割和非采样Contourlet变换的红外和可见光图像融合算法。首先，对红外和可见光图像进行区域分割和区域关联，关联映射图分为目标区域、背景区域和灰度区域。随后，应用NSCT变换对图像进行多尺度、多方向分解，按照关联映射图中三个区域对NSCT分解后的高低频子带系数进行区域划分，根据不同区域的特性在NSCT域设计不同的融合规则。最后，进行重构得到融合图像。对三组不同场景图像的实验结果进行主观目视判别和客观性能评价，对比基于像素和邻域能量的融合算法，本文算法不仅能较全面的保持可见光图像中的光谱信息，而且能够有效、准确的提取红外图像的热目标信息，优于传统的基于像素和邻域能量的融合算法，可获得较理想的融合图像。     

基于自适应窗口固定及传播的 多尺度纹理图像分割

 本文提出一种基于自适应窗口固定及传播的多尺度纹理图像分割方法,在小波域隐马尔科夫树模型(WHMT)的初始分割基础上,根据分割粗尺度上的区域一致性好,细尺度上的边缘准确的特点,利用上下尺度像素之间以及本层邻域像素的马尔科夫性,标记出图像的一致性区域和边缘区域,将一致性区域固定,类标直接下传到下一尺度,边缘区域则利用邻域信息确定出上文权值背景传播到下一尺度,与下尺度一起共同指导图像分割,从而很好的保持了区域均匀性和边缘准确性.同时根据纹理图像区域聚集性的特性,利用基于多项式展开和置信区间交叉(LPA_-ICI)方法找出各类区域聚集的物理位置中心,融入上下文权值背景中,使得指导分割策略能够更好的进行.实验表明,对于合成纹理图像来说,本文提出的多尺度融合算法在均匀区域内部及区域边界都大为改善,而且无须进行参数的训练,使算法快速的完成.     

空间变化离焦模糊红外图像快速复原算法

为了提升空间变化离焦模糊红外图像的图像质量,提出了一种基于图像质量评价的快速复原算法。本文提出的方法首先对模糊图像采用不同点扩散函数对应的截断约束最小二乘法算法进行复原而获得多幅复原图像,并对复原图像进行去振铃;然后对复原图像中每个像素为中心的区域进行图像质量评价,将采用不同参数复原的图像以图像质量评价的结果进行组合以获得最终的复原图像。由于无需对模糊图像点扩散函数估计,且采用了空间域运算的截断约束最小二乘法算法进行图像复原,实验结果表明,本文提出的算法能够对空间变化离焦模糊红外图像进行快速复原,算法运行速度较基于点扩散函数估计的方法大幅提升。     

面向统计编码的联合比特分配算法

在统计编码系统中,需根据图像复杂度对各路节目进行联合比特分配,比特分配的准确性直接影响了图像质量.因此对图像复杂度的准确评估是统计编码的难点.鉴于传统的基于预测的算法对复杂度评估存在预测误差,提出了将原始帧作为参考帧,通过并行整像素运动估计计算各编码帧的SAD作为统计所需的复杂度信息,提高了图像复杂度评估的准确性,进而提高统计编码性能.通过测试CBR模式下和提出的统计算法下的视频码率以及图像质量来说明所提出算法的可行性.     

基于邻域信息的SAR图像变化检测

为了减少合成孔径雷达(SAR)图像中乘性斑点噪声对变化检测结果的影响,充分地利用了像素的邻域信息。首先使用邻域比值(NR)方法构造差异图像,然后提出基于邻域信息的模糊C均值聚类(FCM)算法。NR算子在构造差异图像时能够较好地保留图像信息并抑制噪声的干扰。同时将邻域信息引入到FCM算法的目标函数,以邻域加权距离改进了FCM算法在欧式距离计算中的不足,并约束了隶属度函数,减少了噪声对邻域中心像素的干扰。通过以上考虑像素邻域信息的算法,得到了差异图像的聚类结果,从而实现了SAR图像的变化检测。实验结果表明,所提算法较传统的FCM和K-means聚类算法,可以较好地保留图像变化区域的信息,同时提高了SAR图像变化检测的准确度。     

区域指导的激光水下图像插值算法

提出了一种区域指导的激光水下图像插值算法(简称AIU).AIU算法首先采用小波变换,对低频成分进行特殊处理,以抑制散斑噪声和增强关注的目标;然后将图像分割成目标区域和背景区域,结合近邻法和众数法确定待插值点所属区域,对区域内部点采用线性插值;对于区域间的过渡点,设计非线性插值公式,对与待插值点属于同一区域的邻域像素,分配较大的权值,对相邻区域的邻域像素分配较小的权值.实验结果表明,AIU算法可以克服传统插值算法的边缘模糊问题,使目标更完整清晰.     

SIFT改进算法在图像配准中的应用

文中对尺度不变特征变换(SIFT)算法进行分析研究,针对原算法中128维的高维描述子提出60维方形邻域描述子,统计邻域梯度信息.方形邻域描述子较原算法增加了邻域像素统计范围,增强了关键点的邻域信息;在配准阶段采用欧氏距离作为度量函数,用次临近与最邻近之比来对60维描述子进行匹配.通过实验证实,改进算法的匹配时间是原算法的30%～60%,配准精度与原算法相近,对于复杂图像的配准精度较原算法有所提高,适用于对实时性要求较高的图像配准场合.     

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.     

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.     

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.     

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.     

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.     

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.     

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     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its