大蒜挥发油的分离提取工艺研究进展     

徐丽萍  张亚非  吴正勇 《中国科技信息》2011,(14):81-82

综述了大蒜主要有效成分大蒜油的各种提取方法,对各种方法的优缺点进行了简要分析,并对大蒜油的提取工艺和应用的发展方向提出展望。  相似文献   

基于多核系统的视频特征提取程序并行化及性能优化方法     

张琦  陈玉荣  李建国  胡云  许胤龙 《中国科学院研究生院学报》2011,28(4)

基于多核系统,对4种视频特征的提取程序分别研究了并行算法和性能优化方法.实验结果表明,通过的并行化和性能优化,当使用8个核时,这4种视频特征提取程序的处理速度平均提高到原始串行程序的17倍.此外,对实验结果进行了深入的性能分析,寻找和剖析了多核系统的性能瓶颈,为进一步提高多核系统的性能提供了依据和建议.  相似文献   

The semantic mapping of words and co-words in contexts     

Loet Leydesdorff  Kasper Welbers 《Journal of Informetrics》2011,5(3):469-475

Meaning can be generated when information is related at a systemic level. Such a system can be an observer, but also a discourse, for example, operationalized as a set of documents. The measurement of semantics as similarity in patterns (correlations) and latent variables (factor analysis) has been enhanced by computer techniques and the use of statistics; for example, in “latent semantic analysis”. This communication provides an introduction, an example, pointers to relevant software, and summarizes the choices that can be made by the analyst. Visualization (“semantic mapping”) is thus made more accessible.  相似文献   

利用本体关联度改进的TF-IDF特征词提取方法   总被引：3，自引：0，他引：3  

徐建民  王金花  马伟瑜 《情报科学》2011,(2)

针对传统TF-IDF方法提取文本特征词时未考虑词语间关系的不足,提出一种利用本体关联度改进的文本特征词提取方法。该方法首先利用传统的TF-IDF方法构建候选特征词集合和非候选特征词集合,然后根据领域本体知识在非候选特征词集合中提取候选特征词的本体关联词,利用候选特征词与其本体关联词之间的本体关联度以及本体关联词本身的权重调整候选特征词的权重,得到新的候选特征词权重排序。实验证明,该方法能够有效提高文本特征词提取的准确度。  相似文献   

文本分类中基于图模型的特征提取方法     

甄志龙  曾晓勤  韩立新 《情报科学》2011,(8)

文本分类是处理和组织大量文本数据的关键技术之一。为了更加有效地实现文本分类,本文提出了一种基于图模型的文本特征提取方法。该方法利用类别信息在训练数据集上构造邻接带权图及其补图,使得属于同一个类别的样本点的投影尽可能近,不属于同一个类别的样本点的投影尽可能远。这种方法既能够获得文本空间的全局结构信息又可以保留局部结构信息。最后,采用K近邻分类器在20Newsgroups标准数据集上进行训练和测试,并且与基于潜在语义索引的文本分类方法做了比较,文本分类的性能得到很大提高。实验结果表明,本文所提出的方法能够有效地提高文本分类的性能。  相似文献   

The dynamic effect of interactivity on customer engagement behavior through tie strength: Evidence from live streaming commerce platforms     

《International Journal of Information Management》2021

Interactivity, which is a key characteristic of the live streaming commerce environment, fosters users’ active attitudes and behaviors in communications and transactions. However, the literature on live streaming commerce, is scarce, and few studies examine how interactivity influences customers’ non-transactional behaviors from a dynamic perspective. In this setting, based on the stimulus-organism-response (S-O-R) framework, we developed a research model using real-time data to investigate the dynamic effect of interactivity on customer engagement behavior through tie strength in live streaming commerce, which is a relatively new derivative of social commerce. This study developed a text mining method to quantify constructs using a large-scale sample of 3,500,445 online review texts. Our empirical study found that interactivity has a curvilinear relationship with customer engagement behavior. Besides, tie strength plays an intermediary role between interactivity and customer engagement behavior. It was further observed that both tenure of membership and popularity have an important moderating relationship between interactivity and tie strength. The study enriches the relationship marketing theory and live streaming commerce literature. Moreover, this study is one of the first studies to use real-time online data for live streaming commerce research.  相似文献   

Fifty years of information management research: A conceptual structure analysis using structural topic modeling     

《International Journal of Information Management》2021

Information management is the management of organizational processes, technologies, and people which collectively create, acquire, integrate, organize, process, store, disseminate, access, and dispose of the information. Information management is a vast, multi-disciplinary domain that syndicates various subdomains and perfectly intermingles with other domains. This study aims to provide a comprehensive overview of the information management domain from 1970 to 2019. Drawing upon the methodology from statistical text analysis research, this study summarizes the evolution of knowledge in this domain by examining the publication trends as per authors, institutions, countries, etc. Further, this study proposes a probabilistic generative model based on structural topic modeling to understand and extract the latent themes from the research articles related to information management. Furthermore, this study graphically visualizes the variations in the topic prevalences over the period of 1970 to 2019. The results highlight that the most common themes are data management, knowledge management, environmental management, project management, service management, and mobile and web management. The findings also identify themes such as knowledge management, environmental management, project management, and social communication as academic hotspots for future research.  相似文献   

立足“六字”,打造精品课题     

吴志健 《江苏教育研究》2014,(5):70-73

精品课题建设是学校课题研究发展的必由之路,是学校课题管理的重要抓手。打造精品课题的＂六字＂思路是懂、细、新、实、得、文,即方案设计力求可懂,计划设计力争精细,创新培训形式做到换位与分层,夯实过程管理做到分解与原味,精致提炼围绕＂得＂与＂文＂。  相似文献   

人脸表情识别研究的新进展     

施徐敢  赵小明  张石清 《实验室研究与探索》2014,33(10)

人脸表情识别是当前计算机视觉、模式识别、人工智能等领域的热点研究课题。它是智能人机交互技术中的一个重要组成部分,近年来得到广泛的关注,不同领域的研究者提出了许多新方法。本文综述了国内外近年来人脸表情识别技术的最新发展状况,对人脸表情识别系统所涉及到的关键技术:人脸表情特征提取和人脸表情分类,分别做了详细分析和归纳。最后,总结了人脸表情识别的研究现状,并指出了其未来的发展方向。  相似文献   

超临界CO2萃取白簕叶总黄酮工艺的研究     

陈耿廷  黄东燕  黄俊生 《韩山师范学院学报》2014,(6):69-74

采用超临界CO2萃取白簕叶中的总黄酮化合物,通过单因素试验和正交试验,研究了超临界萃取条件（压力、温度、时间、CO2流量）对其总黄酮的影响.实验结果表明,最佳提取条件：萃取压力20 MPa,萃取温度35℃,萃取时间1 h,CO2流量20 L/h.白簕叶总黄酮提取值为2.929 mg/g.  相似文献