融合背景能量项的Graph Cuts PCB CT图像分割

提出了一种新的交互式图像分割方法,该方法通过空间曲面拟合方法生成背景能量项,并将其融入Graph Cuts的分割模型中,以实现对背景灰度不均匀的PCBCT图像分割。本文的方法通过概率模型将自顶向下的全局信息和传统图割模型中自底向上的局部信息有效结合起来,其中背景能量项依据用户添加的背景种子点自适应地生成。通过对多组PCB CT图像进行分割实验,结果表明与经典的Graph Cuts和Grabcut等算法相比,本文方法能得到更准确的分割结果。     

一种基于SAR图像的典型线特征抽取方法

针对合成孔径雷达(Synthetic Aperture Radar)图像的相干斑噪声会使图像的分割和目标的提取困难的问题,文中利用改进的Lee滤波手段去除相干斑噪声,并使用照度均衡算法平衡SAR图像的光照度,最后使用图割(Graph Cuts)算法交互式地对SAR图像中的线性结构进行抽取。实验结果表明Lee滤波和照度均衡算法分别对于抑制相干斑噪声干扰和修正图像对比度有显著效果,图割算法可以有效地提取出用户感兴趣的线性结构。     

基于GMM分类的信道占用度计算方法

信道占用度是无线电频谱监测中衡量信道使用情况的重要指标.本文提出一种基于高斯混合模型(Gaussian mixture model,GMM)的信道占用度计算方法,利用场强作为特征参数,用数据分类算法处理监测数据集,自动分离背景噪声和强弱信号,实现信道占用度的计算.该方法避免了传统算法中的随机误差和估计误差,能更准确地计算信道占用度.     

基于MapReduce网页文本并行化计算的研究

为了快速在浩如烟海的网页里定位用户感兴趣的信息,提出基于Hadoop的网页文本聚类的算法,网页文本以key,value形式存储到分布式文件系统(HDFS),使用基于统计的方法进行分词操作,去噪,特征提取,构建向量空间模型,提出基于Map Reduce实现改进的k-means聚类算法。经实验验证,不同规模的数据集实现分布式计算,数据集越大,聚类效果越好。     

基于说话人识别的GMM/GA算法

在实时平台上,高斯混合模型(GMM)具有计算有效性和易于实现的优点。最大似然规则中,模型参数不断更新,但由于爬山特征,任意的原始模型参数估计通常将导致局部最优;遗传算法(GA)适于求解复杂组合优化问题及非线性函数优化。提出了基于说话人识别的可以解决GMM局部最优问题的GMM/GA新算法,实验结果表明,提出的GMM/GA新算法比纯粹的GMM算法能获得更优的效果。     

基于粗糙模糊集理论的医学体数据场模糊增强算法

提出了一种基于粗糙模糊集理论的医学体数据场模糊增强算法.该算法首先应用粗糙集理论对医学体数据场进行分类,在分类的同时,去除了噪声.然后针对不同的子数据场采用不同的方法进行处理,其中对于体数据场的前景部分采用迭代的模糊集理论方法进行增强.实验结果表明此算法不仅能够有效提高体数据场中感兴趣物体的信息显示度,而且在去除体数场中噪声的同时,也避免了感兴趣物体在绘制显示时背景的"遮挡"现象.     

基于高斯混合模型的车辆字符识别算法

在基于统计方法的车牌字符识别算法中,为了更有效地描述车牌字符特征的类条件概率密度,提出了一种基于高斯混合模型(GMM)的识别方法.首先采用Gabor变换来提取车牌字符的特征参数,然后通过GMM来逼近字符特征的类条件概率密度分布,最后根据得到的类条件概率密度分布函数构造贝叶斯分类器.其中,GMM的参数估计采用EM算法.实验表明,这种方法具有良好的字符识别效果、较强的鲁棒性以及较大的应用价值.     

基于ALS协同过滤算法的个性化推荐研究与应用

随着大数据和数据挖掘技术的不断发展和成熟,个性化推荐越来越发挥着重要作用。为了能够更有效地向用户推荐其感兴趣的产品,文章研究了在Spark平台架构基础上使用ALS协同过滤算法在个性化推荐系统中的应用,并对该系统作了性能和效果的评估。根据实验表明,基于Spark平台的ALS算法能有效地为用户推荐其所感兴趣的产品,从而达到个性化推荐的目的。     

基于DPI的用户兴趣实时分类

近年来,随着大数据发展热潮兴起,电信运营商能获得的DPI数据规模越来越大。如何对如此海量的DPI数据进行实时的挖掘和分类是运营商研究的热点。设计了一种基于混合n-gram特征的URL分类算法和基于Doc2Vec模型的文本分类算法相结合的DPI数据分类方法,大大提高了DPI数据的分类速度和分类准确率,为电信运营商进行精准营销提供了良好的基础。     

一种基于特征值和级联聚类的协作频谱感知方法

为了提高低信噪比(Signal-to-Noise Ratio, SNR)下频谱感知的性能，使用模糊C均值(Fuzzy C-means, FCM)和高斯混合模型(Gaussian Mixture Model, GMM),提出了一种基于特征值和级联聚类的协作频谱感知方法。从接收信号的协方差矩阵中提取特征值构造特征向量，通过在三维空间中执行聚类得到信道是否可用的分类模型，此过程无需获得主用户(Primary User, PU)信号以及噪声功率的先验信息，避免了复杂的门限计算。FCM聚类用于优化GMM聚类的初始参数，有效解决了在低SNR下GMM容易陷入局部最小值的问题。仿真结果表明，该方法降低了GMM的收敛时间并提高了模型分类的准确性，与其他主流方法相比能够有效提升频谱感知的性能。     

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.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

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.