应用LSD和聚类的海天/岸岛线检测算法

红外图像舰船目标检测中,目标通常位于海天/岸岛线附近,预先检测出海天/岸岛线,确定舰船目标的潜在区域,可减少目标检测过程中的搜索范围,降低数据处理量,提高检测速度。针对传统的海天/岸岛线检测算法对不同背景图像适应性差的问题,分析了海天/岸岛线特征,提出了应用LSD线段检测算法和聚类的海天/岸岛线检测算法。首先通过LSD线段检测算法获取图像中局部直线轮廓,然后通过K-均值聚类获取潜在海天/岸岛线区域,最后通过分析潜在海天/岸岛线区域纹理特征确定真实的海天/岸岛线位置。实验结果表明,该方法对多种背景下海天/岸岛线检测适应性强,检测精度高。     

基于自适应阀值Canny算法的海天线检测算法

海天线的检测是研究红外成像末制导技术的一项重要内容,对于识别红外图像中舰艇目标起到非常重要的作用。分析了红外图像的特点,给出了一种基于修正的Canny算法的海天线检测方法,根据所要处理的红外图像自适应选取Canny算法的阀值进行边缘检测,精确提取了海面和天空区域的分界线,即海天线。     

海天背景下红外小目标检测的背景抑制及海天线检测方法

针对复杂海天背景下红外弱小目标难以检测与识别的问题,提出了基于海天线检测实现远距离弱小目标识别的方法。该方法对采集到的红外图像进行相关处理。通过用多级小波变换方法抑制背景杂波噪声提高目标信杂比;然后使用多方向Gabor滤波融合方法增强海天线边缘,并通过霍夫变换方法实现海天线定位和检测;最后通过定位海天线确定海天线附近区域的目标搜寻范围,缩小目标点潜在区,从而提高弱小目标在海天背景下的检测和识别概率。     

基于边界先验双模型贝叶斯决策的红外图像海天线检测

为了解决复杂海面干扰下海天线检测的问题,本文提出了一种基于边界先验双模型贝叶斯决策的红外图像的海天线检测方法。该方法首先将海空背景下的红外图像划分为子图像块,以子图像块的离散余弦变换的主余弦谱作为子图像块特征;然后,基于边界先验建立了海、天子图像块的贝叶斯决策模型,对海、天子图像块进行粗划分;之后,利用粗划分的子图像块集合建立细划分贝叶斯决策模型,利用重叠子图像块滑动细划分方法,获取海天线上候选点;最后,利用随机抽样一致性（RANSAC）算法得到海天线模型参数,实现海天线的检测。实验结果表明,该方法能有效检测出复杂海空背景下的海天线,对于海杂波、亮斑等干扰较多的复杂红外图像具有更优的检测效果,运算速度较快。      

基于纹理特征分析的海天线检测方法

为抑制海空背景干扰和提高舰船检测速度,提出一种基于纹理特征分析的海天线检测方法。分析了典型红外海空背景下海天线区域的纹理分布特征,建立了适用于海天线检测的纹理模型。通过梯度特征计算和聚类分析找出图像中的候选直线位置,比较其纹理参数并准确检测出海天线。对多种复杂背景红外海空图像的实验表明,该方法适应面广,计算简便,具有很好的抗干扰能力。     

基于EmguCV的红外图像海天线提取算法研究

本文基于海天背景目标提取技术的研究,给出一种实用的海天线提取算法。首先,采用空域滤波消除弱小船只目标和近域海浪杂碎波的干扰,对降噪后的红外图像进行形态学梯度运算,采用Ostu阈值分割方法,获取海天线边缘轮廓,然后利用Hough直线检测算法,获取海天线待拟合点数组,最后利用最小二乘法拟合海天线。实验结果表明,本算法能够准确、快速地提取海天线,为海上目标的快速探测跟踪奠定基础,对红外搜救设备进行海上目标探测跟踪具有重要意义。     

海天背景红外图像小目标自动定位方法

通过对舰载红外警戒系统成像进行分析,提出了一种基于交叉算法的海天背景红外小目标的自动定位方法.其基本思路是根据红外图像的特点,首先通过Radon变换域极大值点提取海天线,然后沿海天线平行的方向取与海天线平行的直线,进行频率突变点的检测,最后由海天平行线和频率突变点处坐标共同对红外图像小目标进行定位.试验结果表明,该算法能快速、准确地对目标自动定位.     

基于海天线提取的红外小目标检测方法

通过对海上红外图像进行分析,提出了一种基于海天线提取的红外小目标检测方法。该算法的基本思路是根据所需提取目标的特点,首先选择感兴趣的灰度区域,然后运用Canny算子进行边缘检测,接着对图像进行Hough变换检测海天线,最后对海天线以下且符合目标特征的连通域进行标记从而来确定目标的位置。实验结果表明,该方法能较好地检测出海上红外小目标。     

复杂海天背景下红外舰船目标的自动检测方法

近年来,舰船目标的检测与识别技术得到了人们越来越多的重视.研究了复杂海天背景下红外舰船目标的自动检测问题.首先运用小波变换对图像进行预处理,提高了图像的信噪比,从而抑制了噪声和背景杂波.然后针对红外舰船目标总是出现在海天线附近的问题,采用梯度强度均值分割的算法检测了海天线,确定了目标的潜在区域.最后,提出了一种基于行列均值的自适应阈值分割算法,结合使用红外舰船目标的几何特征量,采用特征匹配方法提取出舰船目标,达到了自动检测的目的.实验结果表明:该方法能有效地自动检测复杂海面背景中的红外舰船目标.     

基于复杂海空背景行均值曲线的海天线定位算法

复杂海空背景下红外舰船目标总是出现在海天线附近,因此获取海天线位置能确定目标的潜在区域。利用海天线区域在背景灰度上的渐变特性,提出了一种海天线定位方法,该方法首先运用形态学开运算抑制高频目标和杂波、提取平滑背景;然后采用背景行均值曲线首次突降区间检测算法,定位出一个窄的海天线区域,其中线即为工程误差范围内的近似海天线。实验结果表明,该海天线定位算法准确率高、适应于复杂海天环境。     

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-