基于多尺度特征残差学习卷积神经网络的视频超分辨率方法

本文提出了一种基于多尺度特征残差学习卷积神经网络的视频超分辨率方法,考虑到视频帧间的时空相关性,所提的方法采用由双三次插值预处理后的连续五帧视频作为卷积神经网络的输入,经由网络重建中间帧作为输出,依次按顺序重建直至获得整个高分辨率视频。本文所提出的卷积神经网络主要由多尺度特征提取、残差学习、亚像素卷积层、残差连接(skip-connection)四大部分组成,通过对视频的多尺度特征的提取获得更丰富的不同尺度特征和残差学习达到较好地恢复高频信息的目的。本文采用峰值信噪比（PSNR）和结构相似性指数（SSIM）作为损失函数优化网络。实验结果表明,本方法在平均评价指标上较其他方法均有一定的提升（PSNR +3.151dB,SSIM +0.102）,从主观评价上看可以有效地减少视频边缘模糊的现象。      

改进的卷积神经网络红外图像超分辨率算法

基于卷积神经网络的图像超分辨率算法可以分为图像尺寸放大和图像细节恢复/增强两个步骤,在细节恢复过程中,卷积层直接从输入图像中学习特征并将该特征作为下一个卷积层的输入数据。为了加强输入图像和卷积层各通道图像的特征表达能力,提出了一种新的卷积神经网络算法,该算法对输入图像和通道图像进行选择性灰度变换而增强特征表达的能力。实验结果表明,在公共红外图像数据集和实验室采集的红外图像数据集上,所提方法的超分辨率重建效果均优于当前的几种典型算法,能够恢复的细节信息更多。     

快速图像超分辨率方法研究

针对现有的基于样本学习的图像超分辨率方法参数较多、运算速度较慢等问题,结合基于卷积神经网络的超分辨率方法,提出一种快速图像超分辨率方法。设计一学习网络,以低分辨率图像作为网络的输入,从根本上减少网络的运算负担,加速网络运算;减小卷积核尺寸使得网络训练参数减少,提高运算速度;最后以亚像素卷积层同时实现网络的映射和图像融合过程。将所提方法在通用测试集上进行测试,并与其他方法的测试结果进行了对比,所提方法生成的图像具有更高的峰值信噪比,且具有更好的主观视觉效果。实验结果表明所提方法不仅运算速度能够得到大幅提升,而且能够生成更高质量的超分辨率图像,具有更佳的超分辨率性能。     

生成式对抗神经网络的多帧红外图像超分辨率重建

生成式对抗神经网络在约束图像生成表现出了巨大潜力,使得其适合运用于图像超分辨率重建。但是使用生成式对抗神经网络重建后的超分辨率图像存在过度平滑,缺少高频细节信息的缺点。针对单帧图像超分辨率重建方法不能有效利用图像序列间的时间-空间相关性的问题,提出了一种基于生成式对抗神经网络的多帧红外图像超分辨率重建方法（M-GANs）。首先,对低分辨率图像序列进行运动补偿;其次,使用权值表示卷积层对运动补偿后的图像序列进行权值转换计算;最后,将其输入生成式对抗重建网络,输出重建后的高分辨率图像。实验结果表明:文中方法在主观及客观评价中均优于当前代表性的超分辨率重建方法。     

多级跳线连接的深度残差网络超分辨率重建

由于快速的卷积神经网络超分辨率重建算法(FSRCNN)卷积层数少、相邻卷积层的特征信息之间缺乏关联性,因此难以提取到图像深层信息导致图像超分辨率重建效果不佳。针对此问题,该文提出多级跳线连接的深度残差网络超分辨率重建方法。首先,该方法设计了多级跳线连接的残差块,在多级跳线连接的残差块基础上构造了多级跳线连接的深度残差网络,解决相邻卷积层的特性信息缺乏关联性的问题;然后,使用随机梯度下降法(SGD)以可调节的学习率策略对多级跳线连接的深度残差网络进行训练,得到该网络超分辨率重建模型;最后,将低分辨率图像输入到多级跳线连接的深度残差网络超分辨率重建模型中,通过多级跳线连接的残差块得到预测的残差特征值,再将残差图像和低分辨率图像组合在一起转化为高分辨率图像。该文方法与bicubic, A+, SRCNN, FSRCNN和ESPCN算法在Set5和Set14测试集上进行了对比测试,在视觉效果和评价指标数值上该方法都优于其它对比算法。     

基于快速超分辨率重建与残差连接的信道估计

将信道估计视为低分辨率图像重建为高分辨率图像,借鉴图像超分辨重建思想,提出了一种基于快速超分辨重建及残差连接思想的信道估计方法——ResFSRNet。采用最小二乘法(Least Square,LS)计算单个正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)子帧中所有导频处的信道响应,将其视为小尺寸低分辨率“图像”作为神经网络输入,利用多个卷积层对其进行特征提取,且融入残差连接提升性能,最后通过转置卷积重构出完整OFDM子帧信道响应。在不同抽头延迟线信道环境中进行仿真,通过信道估计误差和链路误码率结果比较,表明ResFSRNet性能优于LS、实用信道估计及基于超分辨率重建的ChannelNet,且较ChannelNet在减少约99%计算量的前提下提高了约2 dB信道估计性能。     

采用双网络结构的压缩视频超分辨率重建

在实际应用中,为了节省带宽和方便存储,图像和视频通常被下采样和压缩,而降质的图像与视频无法满足人们的实际需求。针对这一问题,采用了一种双网络结构的超分辨率重建方法,首先建立下采视频与压缩后的低分辨率视频的映射关系,然后建立质量增强的压缩视频与原始视频的映射关系,最终在输出端可以得到质量提升的视频帧。在网络中,采用密集残差块来提取压缩视频中丰富的局部分层特征,并结合全局残差学习恢复视频中的高频信息。在压缩环节,采用高性能视频编码来验证所提算法的有效性。实验结果表明,相比于主流的视频编码标准和先进的超分辨率重建算法,所提方法能有效提升编码视频的率失真性能。     

基于迁移学习的红外图像超分辨率方法研究

针对红外图像空间分辨率低、成像质量不高的问题,提出了基于迁移学习的红外图像超分辨率方法。该方法以基于卷积神经网络的自然图像超分辨率方法为基础进行改进:增加网络的层数进行更深层次的学习训练,串联多层小的卷积核使其能够利用更多的图像信息,以“相差图”为目标进行训练,减小网络训练时间,提升网络收敛速度;利用迁移学习知识,再以少量高质量红外图像为目标样本,对自然图像超分辨率的网络进行二次训练,将网络权重经过微调后迁移应用到红外图像的超分辨率上。实验结果表明:基于卷积神经网络的超分辨率方法能够有效迁移应用到红外图像的超分辨率上,且改进后的网络具有更好的自然及红外图像的超分辨率性能,验证了本文所提方法的有效性及优越性。     

基于生成对抗网络的遥感图像超分辨率重建改进算法

为了获取包含更多高频感知信息与纹理细节信息的遥感重建图像，并解决超分辨率重建算法训练难和重建图像细节缺失的问题，提出一种融合多尺度感受野模块的生成对抗网络（GAN）遥感图像超分辨率重建算法。首先，使用多尺度卷积级联增强全局特征获取、去除GAN中的归一化层，提升网络训练效率去除伪影并降低计算复杂度；其次，利用多尺度感受野模块与密集残差模块作为生成网络的细节特征提取模块，提升网络重建质量获取更多细节纹理信息；最后，结合Charbonnier损失函数与全变分损失函数提升网络训练稳定性加速收敛。实验结果表明，所提算法在Kaggle、WHURS19、AID数据集上的平均检测结果较超分辨率GAN在峰值信噪比、结构相似性、特征相似性等方面分别高出约1.65 dB、约0.040(5.2%)、约0.010(1.1%)。     

结合卷积神经网络的HEVC帧内编码压缩改进算法

近年来,卷积网络深度学习已在图像处理、目标检测等领域取得巨大成功。受其启发,将卷积神经网络(CNN)应用于传统视频压缩标准已成为一个新的研究热点。本文提出一种集成卷积神经网络的高效视频编码(HEVC)压缩改进算法,将下采样过程、HEVC的编解码过程、上采样及质量增强过程集成为一体。为高效提取视频帧的结构特征,在所提压缩算法中集成了两个卷积神经网络。提出了一种下采CNN(DwSCNN)代替双三次下采,在有效降低分辨率的同时保留细节信息,得到更为紧凑的低分辨率视频序列,将此低分辨率视频序列通过HEVC帧内编码进行进一步的数据量压缩,通过提出一个质量增强CNN(PPCNN)来改善解码后恢复到原始分辨率的降质视频序列。实验结果显示,本文压缩改进算法在低码率段与标准HEVC相比,能达到更好的质量重建,并且在接近一致的PSNR值时,能节省39.46%的时间和11.04%的比特率,本文算法的视频压缩性能优于HEVC标准算法和相关文献方法。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.