《中图法》四版类目注释"依(按)……排"探讨     

张玉辉 《大学图书情报学刊》2007,25(2):55-57

文章概括了《中图法》四版类目注释中"依(按)……排"的类型,分析了这种注释的作用及存在的问题,并提出了建议.  相似文献   

《中图法》(第四版)法律类目D92的问题及修订建议     

周冬飞 《大学图书情报学刊》2007,25(3):48-49

文章分析了《中图法》法律类目D92中存在的类目设置与法律部门划分不相一致,上下位类目设置缺乏一定的逻辑关系,类目的注释不当,一些新的法律、法规找不到归类的地方,一些已不再适用的法律、法规仍然存在,印刷有误等问题,提出了按照法律部门划分时的要求增设类目、合理调整上下位类间的关系以及正确运用注释等建议。  相似文献   

基于主成分分析的人耳识别系统研究     

祝振宇 《科技广场》2007,(7):33-35

针对人耳识别技术的研究现状,采用主成分分析提取人耳图像特征,在此基础上建立一个人耳识别系统。实验结果验证了利用主成分分析提取人耳图像特征的可行性与高效性,为解决该类问题提供了一个有效的新途径。  相似文献   

毛茛科人字果属的研究     

傅德志 《中国科学院研究生院学报》1988,26(4):249-264

本文对人字果属Dichocarpum W．T．Wang et Hsiao．的形态、花粉和染色体等性     状，以及地理分布进行了系统研究。确认了该属在毛茛科Ranunculaceae中的地位，并认为可     能与星果草属Asteropyrum Drumm．et Hutch．关系较密切, 证实了该属内存在三沟和散沟两     种花粉类型。该属的染色体基数可能为x=6，产于东亚大陆的种为4倍体，日本的种为6倍     体，原始的2倍体种已灭绝。中国西部山地可能为该属的分布中心，日本的种可能是在第三纪由中国大陆迁移过去的。本文按该属内各种之间可能的亲缘关系，作出了系统排列。  相似文献   

基于K-means和Label Propagation的半监督网页分类     

贺松林  张晖 《教育技术导刊》2011,10(2)

提出基于图的半监督学习算法,即类别传播算,结合K均值算法改进,用于网页分类。该K均值类别传播方法使用欧式距离的建立带权∈NN图。在这个图中,图节点表示已标记或未标记的网页,边上的权重表示节点的相似度,已标记节点的类别沿着边向邻居节点传播,从而将网页分类问题形式化为类别在图上的传播。结合K均值方法,提高了计算速度以及图方法的归纳能力,经UCI数据集测试,结果表明,此算法比类别传播算法有更好的性能,能够有效地用于半监督网页分类。  相似文献   

Comparing journal and paper level classifications of science     

Fei Shu  Charles-Antoine Julien  Lin Zhang  Junping Qiu  Jing Zhang  Vincent Larivière 《Journal of Informetrics》2019,13(1):202-225

The classification of science into disciplines is at the heart of bibliometric analyses. While most classifications systems are implemented at the journal level, their accuracy has been questioned, and paper-level classifications have been considered by many to be more precise. However, few studies investigated the difference between journal and the paper classification systems. This study addresses this gap by comparing the journal- and paper-level classifications for the same set of papers and journals. This isolates the effects of classification precision (i.e., journal- or paper-level) to reveal the extent of paper misclassification. Results show almost half of papers could be misclassified in journal classification systems. Given their importance in the construction and analysis of bibliometric indicators, more attention should be given to the robustness and accuracy of these disciplinary classifications schemes.  相似文献   

Time-series classification with SAFE: Simple and fast segmented word embedding-based neural time series classifier     

《Information processing & management》2022,59(5):103044

Dictionary-based classifiers are an essential group of approaches in the field of time series classification. Their distinctive characteristic is that they transform time series into segments made of symbols (words) and then classify time series using these words. Dictionary-based approaches are suitable for datasets containing time series of unequal length. The prevalence of dictionary-based methods inspired the research in this paper. We propose a new dictionary-based classifier called SAFE. The new approach transforms the raw numeric data into a symbolic representation using the Simple Symbolic Aggregate approXimation (SAX) method. We then partition the symbolic time series into a sequence of words. Then we employ the word embedding neural model known in Natural Language Processing to train the classifying mechanism. The proposed scheme was applied to classify 30 benchmark datasets and compared with a range of state-of-the-art time series classifiers. The name SAFE comes from our observation that this method is safe to use. Empirical experiments have shown that SAFE gives excellent results: it is always in the top 5%–10% when we rank the classification accuracy of state-of-the-art algorithms for various datasets. Our method ranks third in the list of state-of-the-art dictionary-based approaches (after the WEASEL and BOSS methods).  相似文献   

DNS tunnels detection via DNS-images     

《Information processing & management》2022,59(3):102930

DNS tunneling is a typical attack adopted by cyber-criminals to compromise victims’ devices, steal sensitive data, or perform fraudulent actions against third parties without their knowledge. The fraudulent traffic is encapsulated into DNS queries to evade intrusion detection. Unfortunately, traditional defense systems based on Deep Packet Inspection cannot always detect such traffic. As a result, DNS tunneling is one problem that has worried the cybersecurity community over the past decade.In this paper, we propose a robust and reliable Deep Learning-based DNS tunneling detection approach to mine valuable insight from DNS query payloads. More precisely, several features are first extracted by the DNS flow, and then they are arranged as bi-dimensional images. A Convolutional Neural Network is used to automatically and adaptively learn spatial hierarchies of features to be used in a fully connected neural network for traffic classification. The proposed approach may result in an extremely interesting task in predictive security approaches to attack detection.The effectiveness of the proposal is evaluated in several experiments using a real-world traffic dataset. The obtained results show that our approach achieves 99.99% of accuracy and performs better than state-of-the-art solutions.  相似文献   

代理人与建议者:中国地方人大代表角色的新分类——以四川省乐山市为例     

黄曦鹏 《乐山师范学院学报》2014,(8):108-115

地方人大代表的角色认知涵盖了人大代表在实际政治活动中是什么、做什么、以什么身份说话和行动等内容,对于理解地方人大代表的行为以及地方人大的实际运转情况有着重要的作用。文章是角色理论出发,以乐山市的调研材料为例,与欧博文(Kevin J.O’Brien)的经典实证研究进行对勘,分析地方人大代表的角色认知并分类。在欧博文原有理论基础上讨论了国家代理人型代表的消失,不活跃代表的进一步分类和持异见者型代表的变化等问题,对该理论模型进行了修正。  相似文献   

英国图书馆学家布朗分类思想探析     

王宇 《山东图书馆季刊》2014,(2):37-41

英国图书馆学家詹姆斯·达夫·布朗的《主题分类法》在世界图书分类历史上占有重要的位置。本文对布朗所创立的分类理论和实践进行了讨论,介绍了其著作《主题分类法》及其所体现出来的非恒定性、学科互涉、一个主题,一个位置等的分类思想,阐述了他对于学科间复杂关系的重要性的认识,以及他的思想对后世分类研究人员的影响。  相似文献