基于支持向量机与谱特征的数字信号识别

由于已有的调制识别方法存在提取的特征参数多、计算量复杂等不足,现提出一种将支持向量机与谱特征结合的方法,该法不仅提取的特征参数少,对噪声不敏感,计算量小,而且还通过设计分级的支持向量机分类器提高了识别率．仿真实验表明,这种方法比普通的阈值法在识别率方面有明显的改善．     

柱矢量光束的角动量

按照电磁场角动量的一般定义,研究了非近轴柱矢量光束的角动量,发现其自旋角动量主要取决于光束的偏振情况,而轨道角动量不仅取决于光束的波前相位因子,还与光束的偏振情况相关,并且都与光束的结构有关。即使在近轴近似下。柱矢量光束的角动量也不能自然地分解为互不相关的自旋角动量和轨道角动量两部分。     

Local word vectors guiding keyphrase extraction

Automated keyphrase extraction is a fundamental textual information processing task concerned with the selection of representative phrases from a document that summarize its content. This work presents a novel unsupervised method for keyphrase extraction, whose main innovation is the use of local word embeddings (in particular GloVe vectors), i.e., embeddings trained from the single document under consideration. We argue that such local representation of words and keyphrases are able to accurately capture their semantics in the context of the document they are part of, and therefore can help in improving keyphrase extraction quality. Empirical results offer evidence that indeed local representations lead to better keyphrase extraction results compared to both embeddings trained on very large third corpora or larger corpora consisting of several documents of the same scientific field and to other state-of-the-art unsupervised keyphrase extraction methods.     

On teaching about the coefficient of variation in introductory statistics courses

The standard deviation is related to the mean by virtue of the coefficient of variation. Teachers of statistics courses can make use of that fact to make the standard deviation more comprehensible for statistics students.     

Word sense disambiguation based on context selection using knowledge-based word similarity

In this paper, we introduce a novel knowledge-based word-sense disambiguation (WSD) system. In particular, the main goal of our research is to find an effective way to filter out unnecessary information by using word similarity. For this, we adopt two methods in our WSD system. First, we propose a novel encoding method for word vector representation by considering the graphical semantic relationships from the lexical knowledge bases, and the word vector representation is utilized to determine the word similarity in our WSD system. Second, we present an effective method for extracting the contextual words from a text for analyzing an ambiguous word based on word similarity. The results demonstrate that the suggested methods significantly enhance the baseline WSD performance in all corpora. In particular, the performance on nouns is similar to those of the state-of-the-art knowledge-based WSD models, and the performance on verbs surpasses that of the existing knowledge-based WSD models.     

Rn中向量的正交化

利用矩阵的第三种到初等变换,把R~n中任意一组线性无关的向量组化为正交组。     

Mini-research Experience in Simple Linear Regression

Within the undergraduate mathematics curriculum, the topic of simple least-squares linear regression is often first encountered in multi-variable calculus where the line of best fit is obtained by using partial derivatives to find the slope and y-intercept of the line that minimizes the residual sum of squares. A markedly different approach from linear algebra, which could also be introduced in multi-variable calculus, obtains the regression line by vector projection. The latter viewpoint offers elegant proof of the equation relating the total, explained and unexplained variations. Consideration of data with the same regression line and correlation opens the door for a “mini-research experience” (MRE). A sequel MRE gives rise to an open Research Experience for Undergraduates topic to analyze reflection sequences and a fundamental connection between complex analysis and regression analysis. A few general guidelines and basic goals for MREs are included for those whose main interest is in undergraduate research.     

从教育向量看第二条教育道路的实施

教育空间的运动向量决定了个人职业生涯的不断发展。向量的存在促使在职人员产生继续学习和深造的愿望。德国“第二条教育道路”的实施向在职人员开放了从职业教育通向高等教育的大门，在“学习——工作——学习”之间构筑起一条相互沟通的桥梁。     

论亚里士多德的中道思想

亚里士多德的中道思想是在继承古希腊传统中道思想和结合当时现实社会状况的基础上 ,经过理论论证的系统化的学说 ,它对当时及后世都产生了广泛影响。文章从该思想的历史溯源、含义及其在城邦政治中的体现三方面进行论述 ,这对于把握以“中道”为核心的亚里士多德的伦理思想体系和理解西方社会生活的价值标准具有重要的意义。     

混合动力汽车电机控制模型的仿真建立

通过分析混合动力汽车电机控制的方法,设计永磁同步电机的直接转矩控制系统;建立相应的数学控制模型,并对相关的因素进行分析;通过具体的系统设计,获得相应的仿真结论.