基于Gibbs-LDA和最小二乘支持向量机的物联网安全预测方法

针对物联网中各类用户的网络行为出现复杂化、多样化和恶意化的特征和趋势,提出了一种基于Gibbs—LDA和最小二乘支持向量机的物联网安全预测方法;首先,提取通信时间、地址和内容等文中信息作为多维的通信记录样本,然后基于LDA模型,将安全事件建模为主题,获取样本特征并得到主题模型,通过Gibbs算法来估算LDA模型中的参数,从而建立了基于LDA的物联网安全多维预模型,最后,在LDA特征空间上建立了特征与安全事件分布的权重,并将此权重用于初始化各个支持向量机的预测结果,将权值最大的最小二乘支持向量的预测结果作为最终的结果;仿真实验证明了文中方法能有效地实现物联网安全预测,在NIPS和VAST数据集上进行仿真实验,结果表明了文中方法较其他方法具有预测精度高和预测时间短的优点,具有较大的优越性。     

基于最小一乘和混沌遗传算法检测红外小目标

提出了一种基于最小一乘估计和混沌遗传算法进行背景预测检测红外小目标的方法.在建立最小一乘准则背景预测模型的基础上,根据最小一乘估计的性质,利用混沌序列内在的伪随机性,将混沌引入到遗传算法得到混沌遗传优化算法,以此解决最小一乘估计中极值的选取问题.将原始图像与预测图像相减得到预测残差图像后,利用基于二维指数熵的图像阈值选取快速算法进行分割.给出了实验结果与分析,并与基于遗传算法的最小一乘预测、最小二乘背景预测的检测算法作了比较.实验结果表明,提出的算法具有更高的检测概率和更好的检测结果.     

三维高光谱NPLS模型用于冬小麦估产的初步研究

以35个实验小区,8个生育期的冬小麦田间测量冠层反射高光谱组成三维数据信息阵,采用多维偏最小二乘(multiway partial least squares, NPLS)算法建立了冬小麦亩产量估产模型。模型用于对13个实验小区产量预测分析,预测值与实际值的相关系数ｒ为0.936 6, 平均相对误差为4.44%,说明模型的预测效果较好,对实际的估产工作有一定的指导意义。     

基于FLS-SVM背景预测的红外弱小目标检测

提出了一种基于模糊最小二乘支持向量机(FLS-SVM)进行背景预测、利用模糊Tsallis-Havrda-Charvat熵实现阈值分割的红外弱小目标检测方法。首先采用FLS-SVM对训练样本进行学习得到回归函数,并以此预测红外图像中的背景;然后将原始图像与预测图像相减得到残差图像,并提出基于模糊Tsallis-Havrda-Charvat熵的阈值选取算法分割残差图像,将小目标和噪声从残差背景中分割出来;最后利用目标灰度的平稳性和运动轨迹的连续性进一步检测出真实的小目标。给出了实验结果及分析,并与基于最小二乘支持向量机(LS-SVM)以及基于最小二乘的背景预测方法的检测结果进行了比较。结果表明,该方法具有更高的检测概率和信噪比增益,优于上述基于背景预测的红外小目标检测方法。     

二维相关近红外谱结合NPLS-DA判别掺杂牛奶的研究

将二维相关近红外谱与多维偏最小二乘判别分析方法结合起来,建立了掺杂牛奶与纯牛奶的判别模型.分别配置掺杂尿素牛奶(1～20 g/L)和掺杂三聚氰胺牛奶(0.01～3 g/L)样品各40个,采集纯牛奶及掺杂牛奶样品的近红外光谱.在量化二维相关近红外同步谱的基础上,采用多维偏最小二乘判别分析法分别建立了掺杂尿素、掺杂三聚氰胺及两种掺杂牛奶与纯牛奶的判别模型对未知样品进行判别,其判别正确率分别为95％、90％和92.5％,并与偏最小二乘判别和隐变量正交投影判别建模方法进行了比较.结果表明:多维偏最小二乘判别分析法具有更强的预测能力可推广到其它食品的掺杂检测中.     

褶积反演中的脉冲压缩准则

通过分析基于脉冲压缩原理的反褶积方法,提出了具有广泛用途的广义L_p模准则,像脉冲反褶积、极小熵反褶积、L₁模反褶积和D模反褶积等都为其特例。根据有限维欧氏空间的L。模性质和高维欧氏空间的几何性质,分析了广义L_p模方法中的参数影响。为了比较不同反褶积方法的脉冲压缩效果,给出了一类判别函数,从理论上证明了,为什么对非小相位信号L₁模法的脉冲压缩效果优于脉冲反褶积;D模反褶积要比常规极小熵法更具有"简单性"。广义L_p模准则为构造、分析新的反褶积方法和进一步研究最优脉冲压缩准则提供了必要的理论基础。     

激发-发射荧光矩阵光谱结合多维辩别分析用于葡萄干分类研究

葡萄干因其种类繁杂,产地来源多,制作工艺多样,导致品质各异。因此需要建立能够科学、准确的鉴别葡萄干种类、产地、品质的分析方法,以确保葡萄干产品质量、保护消费者利益、规范葡萄干商品市场。该实验基于葡萄干中富含多种荧光物质,以甲醇为萃取剂,应用微波提取法,结合三维荧光光谱技术,在激发波长300~700 nm,发射波长360~720 nm范围,获取三维荧光矩阵数据,应用多维主成分分析(M-PCA),多维偏最小二乘辨别分析(N-PLS-DA)和平行因子算法-偏最小二乘辨别分析(PARAFAC-PLS-DA)等多维模式识别方法,对三种主色为绿色、两种主色为红色的五个不同种类的葡萄干进了分类研究。M-PCA研究结果显示不同种类的葡萄干存在聚类趋势,而N-PLS-DA和PARAFAC-PLS-DA则给出了比较满意的分类结果。相对而言,由于PARAFAC-PLS-DA是基于PARAFAC分解得到浓度得分结果基础之上进行的分类,去除了不相干的冗余信息,因此取得了100%准确的分类结果。两种算法的品质因子比较结果也说明基于荧光光谱法和多维模式识别技术相结合的分析技术可以很好的用于葡萄干种类的识别研究,并有望用于葡萄干质量等级识别及产地追溯。     

多维声光衍射和多维声光器件

本文建立了沿不同方向的多个超声波信号作用下的多维声光衍射的耦合波方程,并求出相应的解。分析了多维声光衍射的衍射效率、压缩、交叉调制和互调制强度等特性。用我们研制的多维声光器件进行了实验测量,实验结果与理论分析一致。     

基于支持张量机的多维光谱定量分析方法

现代光谱仪器强大的多维光谱数据产生能力使得多维光谱数据定量分析方法成为迫切需要研究的课题。针对多维光谱定量分析中的多维光谱数据以张量模式表达的特点,研究了基于支持张量机的多维光谱定量分析方法。该方法保留了多维光谱数据所固有的结构信息及数据的内在相关性,减少了模型中的待定模型参数,也克服了平行因子法、多维偏最小二乘等方法中需要预估组分数的缺点。对水体中化学耗氧量和总有机碳的检测进行了实验检验。实验结果表明:与现有的多维光谱定量分析方法比较,本方法提高了校正模型性能,并且模型对需预先确定的参数C和ε的变化不敏感。     

近红外光谱预测汽油辛烷值和辛烷值仪的研制

本文报道了用近红外光谱预测汽油马达法辛烷值,研究法辛烷值和抗爆指数的方法。用多重线性回归和偏最小二乘法回归建立辛烷值的预测模型。基于此模型,首次研制成功光学多道近红外辛烷值仪。     

Single frame blind image deconvolution by non-negative sparse matrix factorization

Novel approach to single frame multichannel blind image deconvolution has been formulated recently as non-negative matrix factorization problem with sparseness constraints imposed on the unknown mixing vector that accounts for the case of non-sparse source image. Unlike most of the blind image deconvolution algorithms, the novel approach assumed no a priori knowledge about the blurring kernel and original image. Our contributions in this paper are: (i) we have formulated generalized non-negative matrix factorization approach to blind image deconvolution with sparseness constraints imposed on either unknown mixing vector or unknown source image; (ii) the criteria are established to distinguish whether unknown source image was sparse or not as well as to estimate appropriate sparseness constraint from degraded image itself, thus making the proposed approach completely unsupervised; (iii) an extensive experimental performance evaluation of the non-negative matrix factorization algorithm is presented on the images degraded by the blur caused by the photon sieve, out-of-focus blur with sparse and non-sparse images and blur caused by atmospheric turbulence. The algorithm is compared with the state-of-the-art single frame blind image deconvolution algorithms such as blind Richardson-Lucy algorithm and single frame multichannel independent component analysis based algorithm and non-blind image restoration algorithms such as multiplicative algebraic restoration technique and Van-Cittert algorithms. It has been experimentally demonstrated that proposed algorithm outperforms mentioned non-blind and blind image deconvolution methods.     

Single-frame multichannel blind deconvolution by nonnegative matrix factorization with sparseness constraints

Single-frame multichannel blind deconvolution is formulated by applying a bank of Gabor filters to a blurred image. The key observation is that spatially oriented Gabor filters produce sparse images and that a multichannel version of the observed image can be represented as a product of an unknown nonnegative sparse mixing vector and an unknown nonnegative source image. Therefore a blind-deconvolution problem is formulated as a nonnegative matrix factorization problem with a sparseness constraint. No a priori knowledge about the blurring kernel or the original image is required. The good experimental results demonstrate the viability of the proposed concept.     

三次相位板波前编码系统彩色图像恢复的迭代算法

采用三次相位板进行景深延拓的波前编码系统得到非对称的点扩展函数.为了获得最终清晰的彩色图像.研究了一种基于广义极小残差法(GMREs)的迭代算法,结合Tikhonov规整化方法,并利用多通道处理过程对中间图像进行左卷积恢复.为了消除恢复图像边界的振铃效应,推导了新的光学成像过程数学模型,该模型采用反镜像边界条件并利用直积近似对卷积核进行处理.模拟数据的分析表明,采用多通道处理过程对彩色图片进行恢复时,新的算法在给出精确的反巷积结果的同时能有效地抑制噪声的放大;实验结果显示,较之经典的维纳滤波恢复结果,新算法能够更好的消除边界的振铃和图像边缘的振动波纹.     

The application of deconvolution methods in electron spectroscopy — a review

In this review of the application of deconvolution in electron spectroscopy the operations of convolution and deconvolution are first defined. The theoretical background to direct methods, Fourier Transform techniques and iterative approaches to deconvolution is given. The use of smoothing techniques, the removal of secondary electron background and the determination of broadening functions are then considered. Examples of deconvolution in electron spectroscopy are discussed. These include valence and core levels in XPS, gas-phase UPS studies and resolution enhancement in Auger spectroscopy. Deconvolution of Auger spectra to yield density of states curves is examined. The likely future status of deconvolution in electron spectroscopy is considered.     

等离子体喷射触发气体开关多通道放电特性

为了能够形成稳定的多通道放电,研制了一种等离子体喷射触发气体开关。在触发电极的内部嵌入多个微型激励腔以形成多通道等离子体喷射,从而在主间隙中诱导多通道放电。研究了触发电路连接方式、触发能量和极性对多通道等离子体喷射的影响,比较了开关在两种工作模式下各间隙放电通道数量随工作系数的变化规律。实验结果表明:采用触发电路II连接方式,触发电极的多通道放电效果更好;高触发能量、负极性和低气压条件有利于形成多通道等离子体喷射;当开关运行在工作模式Ⅱ,且在较高工作系数时,具有更好的多通道放电特性。     

Spectral restoration using semi-blind deconvolution method with detail-preserving regularization

Peak-details are often smoothed when deconvolution methods are used for spectral restoration. In order to preserve spectral details, detail-preserving regularization is devised and a semi-blind deconvolution method with the detail-preserving regularization (SBD-DP) is proposed. The cost function of SBD-DP is formulated and the numerical solution processes are deduced for restoring spectra and estimating parameter of blur kernel. The deconvolution results of simulated spectra demonstrate that the proposed SBD-DP can restore the spectrum effectively and has a merit on preserving peak details, as well as can estimate the parameter of blur kernel accurately. Then the deconvolution result of experimental Raman spectrum indicates the effectiveness of the proposed SBD-DP method on improving spectral resolution.     

Deconvolution of very low primary energy SIMS depth profiles

In this paper, the deconvolution of SIMS profiles analysed at very low primary energy (0.5 keV/O₂⁺) is addressed. The depth resolution function (DRF) of the SIMS analysis in presence of roughness is established and a deconvolution procedure is implemented without or in presence of roughness on samples containing delta-doped layers of boron in silicon. It is shown that the deconvolution procedure can lead to a great improvement of the full width at half maximum (FWHM) of the measured peaks in the case where no roughness in detected in the crater bottom. In the case where it is present, the conditions required to use a deconvolution procedure are discussed, and the deconvolution is implemented using precise and restrictive assumptions.     

STUDY ON MULTICHANNEL PASSIVE MILLIMETER-WAVE RADIOMETER IMAGING AND SUPERRESOLUTION

Multichannel passive millimeter-wave (PMMW) imaging systems have advantage in operating speed, however traditional data processing methods for single channel systems are not applicable for such kind of system. This paper describes an 8-mm multichannel PMMW imaging system, points out the specific problems encountered in multichannel systems, and proposes an experimental multichannel calibration approach in microwave unreflected chamber. In the last superresolution algorithms considering imaging process and some related issues are discussed. The imaging result shows the proposed processing approaches are effective.     

一维多通道正常金属结构的透射几率

本文考虑一个严格一维的正常金属多分支结构,指出把Büttiker等人处理两分支结构的方法加以改进。即可解决这种多分支结构问题。我们给出了多分支结构的透射系数公式,作为一个简单的例子,求出了一个对称三分支结构的具体结果,并表明在这种结构中存在透射几率的共振现象。 关键词：     

Measurement Error Correction for Distributed Properties – Filter Cake Thickness Measurements

The measurement of a distributed property is frequently encountered in engineering applications. The impact of a possible measurement error on the measured distribution is described and two methods to account for such an error are detailed: A Fourier transform based deconvolution procedure and a moment based deconvolution approach via kernel estimators are presented. The deconvolution methods can be used in many particle characterization and process applications where particle features or properties are commonly presented in a distributed form. In the current instance, these methods are carefully explored by using artificially generated data and applied to experimental data obtained from filter cake thickness measurements.