基于空时融合隐马尔科夫模型的舰艇编队目标识别方法

基于末制导雷达搜索舰艇编队目标时获得的目标大角域高分辨距离像(HRRP)信息,该文建立了描述单个HRRP样本内向量之间统计关系的各态历经空间隐马尔可夫模型(SHMM)和描述HRRP样本之间统计关系的从左到右时间隐马尔可夫模型(THMM)。与对一类目标全方位角训练数据只建立一个THMM模型的方法相比,该方法充分利用目标的大角域HRRP信息,提高了识别性能。通过对5类舰船目标的仿真和3类民用船只的外场实测数据分析表明该方法的有效性。     

雷达高分辨距离像目标识别研究进展

雷达高分辨距离像(HRRP)包含了目标的结构信息,在雷达目标识别领域有良好的应用前景.该文详细讨论了基于HRRP的雷达自动目标识别的关键技术及研究现状,包括雷达HRRP的特性、预处理方法、特征提取方法及分类器设计方法等.最后讨论了雷达HRRP识别的研究方向.     

雷达高分辨距离像子带融合识别算法

针对雷达高分辨距离像（HRRP）目标识别问题,对目标回波进行子带划分,分别进行幂变换预处理获得子带距离像,通过实验证明HRRP不同频段的子带距离像均含有目标信息,可以从中提取特征信息用于目标识别。提出一种相关系数相加法子带融合识别算法,由于该方法充分利用了回波信息,因而能获得更好的识别性能,实验仿真验证了这一结论,分析表明算法具有计算复杂度低的优点,因此可实际应用于雷达自动目标识别。     

基于一维卷积神经网络的HRRP雷达目标分类方法

雷达一维高分辨距离像(high resolution range profile, HRRP)信号能够反映目标的结构信息,且具有易于获取的优势,因此利用雷达HRRP回波信号对目标进行分类识别获得了广泛的关注。传统的分类识别方法大多基于提取人工设计的特征然后利用分类器进行分类。然而人工设计提取的特征依赖于专家的先验知识,且人工设计的特征在识别性能上已经趋于平稳。本文将神经网络引入HRRP分类识别中,提出一种基于一维卷积神经网络的HRRP雷达目标分类识别方法。所提方法根据HRRP数据的形式,采取一维的神经网络算子构成一维卷积神经网络。且在网络主体采用一种纺锤形状的残差结构,该结构能够在提取深层抽象特征的同时有效减轻梯度消失和梯度爆炸问题。所提方法在多个数据集上相比于传统对比方法取得了更好的分类识别性能。     

一种利用强度信息的雷达HRRP自动目标识别方法

 针对雷达高分辨距离像(HRRP)的幅度敏感性,现有HRRP雷达自动目标识别(RATR)方法一般简单地能量归一化.本文借鉴切空间距离的思想,提出一种利用HRRP回波强度信息提高识别精度的方法,实测数据仿真试验证明与传统方法相比,该方法可提高识别率约5个百分点.     

GA优化的稀疏分解在雷达目标识别中的应用

特征提取是雷达目标识别系统中很关键的环节,获得一种稳健的目标特征尤为重要。可以利用稀疏分解的方法把雷达高分辨距离像(HRRP)表示在一个超完备Gabor时频字典上,进而提取字典原子的特征参数作为特征向量进行识别;针对匹配追踪算法计算量大的问题,利用遗传算法搜索能力强收敛速度快的优点对OMP算法进行改进。通过对雷达高分辨距离像(HRRP)的识别实验表明,采用Gabor原子提取的特征参数作为特征向量对雷达目标的分类效果比较好。同时,基于GA改进的OMP算法大大降低了参数寻优的计算量。     

单脉冲末制导雷达舷外有源雷达诱饵检测研究

舷外有源雷达诱饵通过与舰船形成双目标非相干干扰,对单脉冲末制导雷达的角跟踪系统产生真正的角度欺骗,影响反舰导弹对舰船的可靠跟踪。单脉冲末制导雷达接收机输出信号在一定条件下近似为高斯分布,采用GLRT方法可以对舰船和诱饵进行检测。     

基于高分辨一维距离像及其特征的空间目标识别效果分析

目标高分辨一维距离像(High Resolution Range Profile, HRRP)中包含了丰富的目标尺寸、结构等目标特征,是进行空间目标身份识别的有效途径。但由于卫星宽带雷达实测数据获取难度大,前期相关研究多集中于基于HRRP的目标识别算法,结论也多是基于仿真数据和少量类别(几类)的前提下得到的,与工程应用实际情况有较大差距,工程指导意义有限。为解决这一问题,基于地基雷达获取的30类卫星目标的大量一维距离像实测数据,从识别正确率的角度对目标HRRP及其特征(组合)的可分性和在空间目标个体识别中的应用效果进行了量化分析,分析结果可为后续基于HRRP的空间目标个体识别技术研究和工程应用提供可靠依据。     

基于核主分量分析和支持矢量数据描述的雷达目标模糊识别方法

针对雷达目标高分辨距离像(HRRP)存在大量的信息冗余,易受到噪声的污染,可分性较差等问题,本文利用核方法解决非线性问题的优点,提出了基于核主分量分析(KPCA)的雷达目标HRRP特征提取与基于支持矢量数据描述(SVDD)的雷达多目标模糊识别方法.在特征提取过程中,利用KPCA对雷达目标HRRP做降噪与降维处理,使得HRRP降低噪声和姿态角的敏感性;在识别过程中,首先在特征空间求得包含每一类目标训练样本的最小超球体,然后根据各个测试样本到最小超球体球面的距离构造属于各个类别的模糊隶属度,根据模糊隶属度的大小判断测试样本所属的类别.仿真实验结果表明,本文提出的算法应用于雷达多目标识别时,具有较高的正确识别率;同时基于SVDD多目标模糊识别算法训练过程只需对每一类目标进行训练,因此具有计算量小,稳健性能优等优点.所以本文提出的KPCA特征提取与SVDD雷达多目标模糊识别方法有很强的实用性.     

毫米波导引头港口舰船目标识别技术

针对末制导导引头对港口多个舰船目标识别、分选的技术难点,该文将距离高分辨技术与单脉冲测角体制相结合,提出了一种基于毫米波单脉冲三维成像的港口舰船目标识别、分选方法。首先采用单脉冲三维成像获得目标散射中心的三维分布,然后利用聚类分析等方法实现目标的分割与识别,并将无偏几何中心法用于目标跟踪点的选择,从而实现导引头对多个舰船的识别、分选及精确跟踪。仿真结果表明,文中方法对多个目标的识别及目标要害部位选择具有很大的优越性。     

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.