???????????????????????

保持近邻投影是一种无监督线性降维方法,具有保持数据流形上局部近邻结构特性,但应用到分类任务时具有局限性,如忽略类标签的信息。该文提出一种新的人脸识别子空间学习方法——监督保持近邻投影,根据先验的类标签信息保持局部几何关系,能获得较好的近似人脸流形以及增强特征空间的判别力。在ORL人脸数据库上的实验表明该方法是有效的。     

Analysis of the Univariate Microaggregation Disclosure Risk

Microaggregation is a protection method used by statistical agencies to limit the disclosure risk of confidential information. Formally, microaggregation assigns each original datum to a small cluster and then replaces the original data with the centroid of such cluster. As clusters contain at least k records, microaggregation can be considered as preserving k-anonymity. Nevertheless, this is only so when multivariate microaggregation is applied and, moreover, when all variables are microaggregated at the same time.When different variables are protected using univariate microaggregation, k-anonymity is only ensured at the variable level. Therefore, the real k-anonymity decreases for most of the records and it is then possible to cause a leakage of privacy. Due to this, the analysis of the disclosure risk is still meaningful in microaggregation.This paper proposes a new record linkage method for univariate microaggregation based on finding the optimal alignment between the original and the protected sorted variables. We show that our method, which uses a DTW distance to compute the optimal alignment, provides the intruder with enough information in many cases to to decide if the link is correct or not. Note that, standard record linkage methods never ensure the correctness of the linkage. Furthermore, we present some experiments using two well-known data sets, which show that our method has better results (larger number of correct links) than the best standard record linkage method.     

基于SLPP与MKSVM的痛苦表情识别

为提高痛苦表情识别的准确率,提出一种基于监督保局投影（SLPP）与多核线性混合支持向量机（MKLMSVM）的识别方法。引入先验类标签信息的SLPP获取痛苦表情特征,以解决保局投影方法在未使用先验类标签信息的情况下忽略类内局部结构的问题,并采用MKLMSVM实现痛苦表情的分类。实验结果表明,该方法的识别准确率可达88．56％,明显优于主动外观模型方法,与一般的支持向量机分类相比,可以提升决策函数的可解释性及分类性能。     

DOA estimation method of weak sources for an array antenna under strong interference conditions

The concept of a preserving source orthogonality and characteristic beam is defined according to an array data model. It is proven theoretically that the corresponding eigenvectors maintain the preserving orthogonality when the powers and the angle intervals between the signals are large. The theory is then applied to the direction of arrival (DOA) estimation for the array antenna in the presence of strong interference. A novel DOA estimation algorithm based on the elimination of the eigenvectors of interference is proposed. The simulation results and comparison of the jamming jam method (JJM) algorithm show that the proposed algorithm does not require the position of the interference source to be known. Moreover, its interference suppression ability and statistical estimation performance are superior to those of the JJM, and thus, it is more suitable for low SNR and small angle intervals.     

基于直接局部保持投影和尺度不变特征变换的人脸识别方法

尺度不变特征变换(SIFT)算法提取的人脸特征具有一定的鲁棒性,但存在数据维数过高和计算过于复杂的问题。为此,提出一种基于直接局部保持投影-尺度不变特征变换(DLPP-SIFT)的人脸识别算法。首先采用SIFT算法进行特征提取,然后结合子空间方法局部保持投影(LPP)进行降维,利用直接对角化方法求取特征矩阵,解决了LPP的奇异值问题。在ORL和FERET人脸库的实验结果表明,DLPP-SIFT算法可显著减少计算复杂度和特征匹配时间,与SIFT、主成分分析(PCA)-SIFT、LPP-SIFT相比,具有更好的鲁棒性。     

动态商空间模型及其基本性质

为解决动态环境下的问题求解,在原有的商空间模型公式研究在这种情况下构成商空间链的充分必要条件,建立相应的商逼近原理,并讨论其基本性质。最后举一个利用动态商空间模型进行问题求解的应用例子。     

基于奇异值分解和判别局部保持投影的多变量时间序列分类

针对现有多变量时间序列分类算法存在的要求序列等长和忽视类别信息两个不足,提出基于奇异值分解(SVD)和判别局部保持投影的分类算法。该算法基于降维思想,先通过SVD将样本的第一右奇异向量作为特征向量,以此将不等长序列转化为规模大小相同的序列;接着采用基于最大间距准则的判别局部保持投影对特征向量投影,充分利用类别信息以确保投影后同类样本尽量接近,异类样本尽量分散;最后在低维子空间采用1最近邻(1NN)、Parzen窗、支持向量机(SVM)和朴素Bayes分类器进行分类。在Australian Sign Language(ASL)、Japanese Vowels(JV)和Wafer三个公开的多变量时间序列数据集上进行的实验结果表明：在时间开销基本不变的前提下,所提方法取得了较低的分类错误率。     

虾保鲜剂的研制

为延长南美白对虾的保鲜期,本论文以壳聚糖和山梨糖醇等为主要成分与常用防腐保鲜剂进行比较研究.在一定的低温(4℃件下,将市场上新购的活虾,在不同的保鲜剂溶液中浸泡3～5 min,在虾体的体表形成一层保护膜. 在贮藏期间以细菌总数、TVB-N值、pH值和感官评定等作为鲜度指标定期取样测定. 实验结果表明:5%的水溶性壳聚糖、10%的山梨糖醇与4%L-异抗坏血酸钠等复配而成的天然保鲜剂用于南美白对虾的保鲜效果显著. 与空白对照组相比,可延缓细菌总数增长2～3d,5d内抑制TVB-N值在30. 0×10-2mg/g以下,维持了较低的pH值.本论文将对提高虾的品质,促进我国水产加工业的健康发展,具有重大的意义.     

偏振保持光纤的研制(熊猫型)

本文重点介绍熊猫型双折射偏振保持光纤的制作工艺、结构和性能参数。     

无汞浆层纸的物理性能

本文通过对湿电阻,饱和度,保液性的测定,比较了含有缓蚀剂的无汞浆层纸和含汞浆层纸物理性能的优劣。实验结果表明:无论P型或C型无汞浆层纸的物理性能均优于含汞浆层纸的。含缓蚀剂的浆层纸可望替代含汞浆层纸。另外,浆层纸的湿电阻与其饱和度和保液性有一定联系。