采用联合域字典稀疏表示的极化SAR图像分类

针对传统字典学习算法难以有效保持极化SAR图像的空间结构以及难以处理大规模数据的问题,提出了一种基于空域和极化域的联合域字典学习和稀疏表示的分类方法.该方法采用基于联合域流形距离的快速AP聚类进行字典学习.利用局部线性编码对极化SAR图像进行空域和极化域的联合域稀疏表示,充分利用了极化SAR数据集潜在的信息,有效保持极化SAR数据结构的同时降低了算法的时间复杂度.试验结果表明:所提算法适应性强,收敛速度快,能够提高极化SAR图像的分类精度.     

基于稀疏编码空间金字塔模型的零样本学习

针对目前零样本图像分类均采用图像底层视觉特征训练属性分类器而导致分类精度较低的问题,提出一种基于稀疏编码空间金字塔模型的零样本学习方法,给出系统结构流程图.首先从原始视觉图像中提取SIFT特征,并进行SIFT特征点提取;然后构建空间金字塔最大池化模型,对已提取的SIFT中间特征进行稀疏编码;最后建立间接属性预测模型.给出基于稀疏编码的空间金字塔最大池化模型的零样本学习算法步骤,完成对目标图像的属性预测,从而达到零样本图像分类的目的.在Shoes数据集与OSR数据集上进行了对比试验.结果表明:试验证实了文中算法的有效性;相对于传统算法,试验耗时减少,图像属性预测精度增加,图像分类识别率提高.     

基于高分辨率SAR的目标识别技术研究

本文以高分辨率SAR在舰船目标识别方面的应用为研究对象,论文首先分析了SAR成像的特点,提出一种基于Radon变换和直方图分析等方法改善舰船目标几何特征提取的性能,在此基础上,结合SAR图像舰船目标分类自身存在的问题和特点,引入稀疏表示理论,提出一种基于特征字典的稀疏表示分类算法,将其应用于Terra SAR-X SAR图像中三类典型舰船目标分类识别,验证了稀疏表示分类对SAR图像舰船目标分类识别的有效性。     

基于3D-OMP算法的SAR动目标成像方法

针对稀疏场景下的SAR动目标成像问题展开研究，提出一种基于三维正交匹配追踪(3D-OMP)算法的稀疏成像方法。首先对成像区域进行网格划分，然后以运动目标的二维速度作为动态参数构建三维稀疏字典矩阵，即参数化稀疏表征。在算法迭代过程中，通过计算回波数据矩阵与三维稀疏字典矩阵各层之间的相关度筛选出信号的支撑集。最后利用最小二乘准则，计算出支撑集下目标场景的稀疏表征系数。该3D-OMP算法是经典OMP算法的改进与拓展，因此继承了OMP算法计算复杂度低、信号稀疏特征增强明显的优势，同时具备了重构SAR动目标图像的能力。仿真实验结果验证了该SAR动目标成像方法的有效性。     

基于时延空时滤波的P300波形提取及目标分类算法

提出一种基于时延空时滤波的P300波形提取及目标分类算法.将多通道脑电信号进行时延,利用最小二乘法思想构造代价函数,通过交替优化的方式估计空时滤波器和源信号,使代价函数收敛并得到空时滤波器,实现空域的源分离和时域的波形提取.经过仿真P300数据对算法性能进行验证,结果表明,该算法对P300波形恢复效果优于同类型的相关算法.对真实脑电数据进行处理,用算法得到的空时滤波器提取P300源成分作为分类特征,利用训练集得到的P300源成分训练Fisher分类器进行目标分类.结果表明,算法的P300波形提取效果、目标分类准确率及AUC值均优于同类型的相关算法.因此,该算法可有效提取P300波形并进行目标分类.      

基于多尺寸特征叠加的SAR舰船目标检测方法

针对SAR图像中舰船目标的检测问题,单纯基于深度学习的图像处理技术难以达到检测准确性和实时性要求.SAR图像中目标尺寸较小,且易受噪声、光斑干扰,传统方法难以提取精细特征并克服复杂条件下的背景干扰.针对以上问题,设计基于YOLOv3检测框架的端到端检测模型,借鉴了残差模块结构来避免网络退化问题.同时结合深层与浅层的不同尺寸特征图检测,使用目标基础特征提取网络参数来避免重复训练初始化过程.针对SAR图像中海上舰船成像小目标的特点改进优化了神经网络结构,实现SAR海面广域舰船目标识别分类算法,并对检测模型进行轻量化压缩处理.构建SAR图像舰船目标数据集并进行了多次目标检测识别分类实验,体现了提出的检测方法在复杂场景下有可靠的抗干扰能力和准确的目标检测识别性能.     

基于稀疏表示的自动年龄估计

将稀疏表示同时应用于人脸图像年龄特征提取和年龄自动估计2个关键环节,提出一种基于稀疏表示的年龄估计新方法。该方法首先对人脸图像进行稠密采样,提取底层的SIFT描述子,训练字典对其进行稀疏编码,再进行空间金字塔表示,并将其作为刻画年龄属性的图像特征,然后采用线性稀疏回归模型同时选择特征进行年龄估计。针对人脸老化过程具有非线性特点,提出一种基于分段线性策略的层次模型,即首先训练若干个分类器将人脸粗分类到不同的年龄段,然后在该年龄段中训练对应的线性模型对年龄进行精确估计。在权威的FG-NET和MORPH人脸库上对该方法的有效性进行实验验证。研究结果表明:所提出的方法在FG-NET人脸库上年龄估计偏差的平均绝对误差为3.79,远比当前最好方法的平均绝对误差低,而在MORPH人脸库上的平均绝对误差为6.46,与当前最好方法的平均绝对误差相当。     

基于胶囊神经网络的合成孔径雷达图像分类方法

针对合成孔径雷达(synthetic aperture radar,SAR)图像的目标分类,传统的卷积神经网络(convolutional neural network,CNN)需要大量的数据样本进行训练,无法在小样本条件下进行,其应用受到限制。提出将胶囊神经网络(capsule network,Capsnet)算法用于SAR雷达图像的分类,针对小样本SAR数据集对Capsnet结构进行轻量化设计,并在MSTAR数据集上验证了该算法的有效性。结果表明,与CNN相比,基于Capsnet的SAR目标分类抗过拟合性强,泛化效果较好,具有更高的准确性,能够很好地实现SAR图像样本的分类。     

基于稀疏表示模型的SAR图像目标检测算法

针对合成孔径雷达（synthetic aperture radar,SAR）图像可视性差、目标区域小以及特征不明显等特性对目标检测造成的困难,将稀疏表示模型应用于SAR图像目标检测,提出一种基于稀疏表示模型的SAR图像目标检测算法。首先,利用K—SVD算法训练样本提取对样本最具描述能力的SIFT特征形成字典;其次,通过将进化机制和稀疏表示结合,逐步提取整幅图像中含有目标的图像块;最后,输出稀疏表示误差小于阈值的图像块的位置作为目标检测的结果。实验结果表明,与传统目标检测算法相比,该算法在检测率和运行效率方面均有一定的提高,取得了较好的效果。     

基于改进稀疏编码模型的图像分类算法

针对图像表示,提出了一种基于改进稀疏编码模型的图像分类算法.首先,提取表示图像视觉局部特征的SIFT (Scale Invariant Feature Transform) 描述子;然后,利用稀疏编码方法生成基于SIFT描述子的视觉词汇库,将SIFT描述子编成稀疏向量;通过有效稀疏向量的区域融合和空间结合而获取整体的稀疏向量并用于图像表示;最后,采用随机森林多分类器对稀疏向量进行训练和测试.结果表明,与现有的算法相比,该算法的性能更佳,可以有效表示图像的特性并提高其分类的准确率.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that