同质背景预测用于红外弱小目标检测

背景预测是红外弱小目标检测中抑制背景的主要方法之一.提出了一种同质背景预测算法,在分析空背景下不同背景成分图像灰度特征模型的基础上,首先对图像进行边缘检测,将图像划分为不同灰度性质的区域,然后使用边缘检测结果调制预测权值矩阵.仿真结果表明,该算法对背景杂波具有很好的抑制效果,能够有效保护图像细节,明显降低异质区域像素灰度对预测的不利影响,显著改善低信噪比条件下弱小目标的检测性能.     

一种红外弱小目标检测方法

提出了一种红外弱小目标检测算法,该算法通过“区域最小化背景模型”,来减小背景起伏对背景预测的影响,从而实现对背景更准确的预测,达到提高弱小目标检测性能的目的,算法适用于强对比度云层的空背景、目标与背景对比度比较低的空背景,是背景预测算法的一个重要扩展,针对实际红外图像的试验仿真表明,提出的算法是有效的。     

基于全卷积神经网络的红外弱小目标检测

为解决传统红外弱小目标检测虚警率较高的问题,提出了一种基于局部均值差分和深度神经网络的红外弱小目标检测算法。首先,利用改进的局部均值差分算法从输入图像中提取候选目标区域;然后设计了基于全卷积神经网络的分类器对候选区域进行判别。网络中引入了参数化非线性激活层,有助于提升网络的分类性能。实验表明该文算法对典型天空和地面背景下红外弱小目标的准确率和召回率分别达到了100%和99.6%,明显优于传统算法。     

远距离红外图像目标分析及背景抑制算法

远距离红外图像的目标检测属于弱小目标检测问题,其图像信杂比低,背景结构边缘的抑制残差是单帧图像目标检测时引入的虚假目标的主要因素.分析了远距离红外图像的目标模型,接着根据目标模型选择合适的预测背景模版,并提出了基于该模版去最近邻算法,最后给出该背景抑制算法的仿真结果.该算法与典型的去均值算法、去中值算法相比抑制背景结构边缘更彻底和抑制后图像具有更高信噪比的优点,能为后续的闯值分割和多帧轨迹关联提供良好条件.     

基于改进YOLOv5的复杂背景红外弱小目标检测算法

针对传统算法依赖于对红外目标与环境背景的精确分离和信息提取,难以满足复杂背景和噪声等干扰因素下的检测需求。论文提出一种基于改进YOLOv5（You Only Look Once）的复杂背景红外弱小目标检测算法。该算法在YOLOv5基础上,添加注意力机制提高算法的特征提取能力和检测效率,同时改进原YOLOv5目标检测网络的损失函数和预测框的筛选方式提高算法对红外弱小目标检测的准确率。实验选取了来自不同复杂背景的7组红外弱小目标数据集,将这些图像数据集进行标注并训练,得到红外弱小目标检测模型,然后从模型训练结果和目标检测结果的角度评估算法和模型的正确性。实验结果表明:改进的YOLOv5算法训练出来的模型,检测准确性和检测速度对比实验列出的几种目标检测算法均有明显的提升,平均精度均值（mean Average Precision,mAP）可达99.6%以上,在不同复杂背景下均可有效检测出红外弱小目标,且漏警率、虚警率低。     

基于杂波抑制的海平线红外弱小目标检测

针对红外图像中海天交接处目标能量较弱,难以获得精确检测的问题,本文提出一种基于杂波抑制的海平线弱小目标检测方法。该方法通过对红外图像特征分析,检测海平线像素特征,去除障碍物干扰,确定海平线区域;对海平线区域采用改进的均值差滤波与背景建模,去除海平线杂波;杂波滤除后,计算两个区间自适应阈值作为滞后阈值,从而检测出海平线弱小目标像素。实验结果表明,本文提出的算法能够有效去除海平线杂波,确定海平线区域,有效提取海平线像素,从而准确检测出海平线弱小目标,具有较高的检测率与较低的虚警率,验证了该算法的有效性。     

基于自适应SUSAN各向异性扩散的红外弱小目标检测

针对复杂背景下红外弱小目标提取困难的问题,提出了一种自适应SUSAN各向异性扩散的红外弱小目标检测算法。该算法结合SUSAN边缘检测算子与各向异性扩散,形成新的扩散方程对红外图像进行背景预测,与原图像差分后实现弱小目标检测。为使算法具备自适应能力,提出SUSAN边缘检测器灰度差阈值的自适应设定方法,采用绝对偏差中值算子作为其扩散系数。实验结果表明,该算法能够有效滤除复杂图像背景,大幅提升信噪比,同时保留目标大小。     

基于MRF的自适应正则化红外背景杂波抑制算法

针对复杂背景下红外弱小目标检测难题,将背景杂波抑制归结为从原始红外弱小目标图像中重建目标数据的过程,据此提出了一种基于马尔可夫随机场模型(MRF)的自适应正则化滤波算法.该算法采用MRF,建立了红外弱小目标图像的先验概率模型,并根据图像的粗糙度设计了新的势函数.在此基础上,采用MRF对背景杂波抑制过程进行正则化处理,从而实现了对红外背景杂波的自适应各向异性抑制.理论分析与实验结果表明,该算法能够随图像局部纹理特征的变化自适应地调整滤波算子结构,从而可在复杂背景下自适应地抑制杂波、增强信号,有效地提高了图像的信噪比,且该算法结构简单,更易于硬件实时实现.     

基于多向梯度背景预测的红外目标检测算法

为解决复杂空中背景下红外弱小目标的检测,提出一种新的基于多向梯度的背景预测方法。该方法根据云层边缘区域、平缓背景区域及弱小目标所呈现的不同梯度特点,采取不同方法分别进行预测;基本保留云层边缘区域和平缓背景区域的点,而对弱小目标区域采用邻域低灰度值点进行预测。然后经过背景消除和阈值分割,将弱小目标检测出来。仿真结果表明,该算法对复杂空中背景预测有很高的准确性,能够更加有效地抑制云层边缘引起的虚警,将红外弱小目标点检测出来。     

基于显著性与尺度空间的红外弱小目标检测

针对复杂的天空背景,提出了一种基于显著性与尺度空间的红外弱小目标检测算法.首先通过频域残差法对原始图像进行初步处理,缩小红外弱小目标的待识别目标区域;接着利用DoG算子得到预处理后图像的尺度空间并实行特征点检测,获得最佳尺度图像,再对特征图像进行加权融合;最后通过信息熵分割来实现红外弱小目标的检测.仿真结果表明,本文方法跟文献中所提的优秀算法相比,能有效地检测出红外弱小目标,提升了目标图像的信杂比.同时,能很好地适应不同复杂场景,为红外弱小目标的跟踪应用奠定了基础.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.