首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   167篇
  免费   8篇
化学   57篇
综合类   1篇
数学   23篇
物理学   12篇
无线电   82篇
  2023年   1篇
  2022年   2篇
  2021年   7篇
  2020年   3篇
  2019年   2篇
  2018年   4篇
  2017年   7篇
  2016年   4篇
  2015年   2篇
  2014年   15篇
  2013年   8篇
  2012年   5篇
  2011年   3篇
  2010年   11篇
  2009年   10篇
  2008年   13篇
  2007年   7篇
  2006年   22篇
  2005年   22篇
  2004年   16篇
  2003年   3篇
  2002年   5篇
  1997年   2篇
  1994年   1篇
排序方式: 共有175条查询结果,搜索用时 0 毫秒
31.
With the rapid development of artificial intelligence technology, text categorization technology is becoming more and more mature. However, text categorization in real situations still faces various unconstrained conditions. English text is an important part of text information, it is also an important way for people to get information from abroad. How can everyone get the desired content from the massive data quickly and accurately, it has become a hot issue in current research. This paper improves the current text categorization algorithm based on English quality-related text categorization. The design and implementation of text categorization system are illustrated with an example of English quality-related text categorization system, complete the research work of text categorization algorithm. The core work of this paper is to mine, classify and analyze large amounts of data in English text by using the method of combining cyclic neural network with quality. Finally, the essential features of high quality English texts are obtained. Traditional English text categorization algorithm if the amount of training data is large, it is easy to show some defects such as unclear feature items. In view of these problems, in order to improve the accuracy and flexibility of English text categorization, this paper proposes a quality-related English text categorization method based on cyclic neural network. A mechanism combining attention is proposed to improve the problem of label disorder and make the structure of the model more flexible. The model proposed in this paper is compared and optimized. Experiments show that the accuracy of neural text classification based on quality classification can reach about 96%.  相似文献   
32.
《电子学报:英文版》2017,(6):1261-1268
With the rapid growth of inquiry in biomedicine concerning diseases, the recognition of diseases becomes especially important. But only the recognition of the biomedical concepts in literature is not enough, annotations and normalizations of the concepts with normalized Metathesaurus get even more important. This paper proposes a system to annotate the literature with normalized Metathesaurus. First, a two-phase Conditional random fields (CRFs) is used to recognize the disease mentions, including the location and identification. Then, the paper adapts the Disease ontology (DO) to annotate the diseases recognized for normalization by computing the similarity between disease mentions and concepts. According to the similarities, the disease mentions are denoted as disease concepts and instances distinctively. The experiments carried out on the Arizona disease corpus show that our system makes a good achievement and outperforms the other works.  相似文献   
33.
Bio-entity name recognition is the key step for information extraction from biomedical literature. This paper presents a dictionary-based bio-entity name recognition approach. The approach expands the bio-entity name dictionary via the Abbreviation Definitions identifying algorithm, improves the recall rate through the improved edit distance algorithm and adopts some post-processing methods including Pre-keyword and Post-keyword expansion, Part of Speech expansion, merge of adjacent bio-entity names and the exploitation of the contextual cues to further improve the performance. Experiment results show that with this approach even an internal dictionary-based system could achieve a fairly good performance.  相似文献   
34.
Fast text location based on discrete wavelet transform   总被引:2,自引:0,他引:2  
The paper describes a texture-based fast text location scheme which operates directly in the Discrete Wavelet Transform (DWT) domain. By the distinguishing texture characteristics encoded in wavelet transform domain, the text is fast detected from complex background images stored in the compressed format such as JPEG2000 without full decompress. Compared with some traditional character location methods, the proposed scheme has the advantages of low computational cost, robust to size and font of characters and high accuracy. Preliminary experimental results show that the proposed scheme is efficient and effective.  相似文献   
35.
36.
李念永  梁艳梅  张舒  杨立  常胜江 《光子学报》2014,38(10):2712-2716
针对复杂彩色图像中文本的特征,提出了基于小波变换和BP神经网络甄别文本区域的算法.该算法首先利用文本块的边缘特征遴选出备选图像块,而后采用小波变换提取备选图像块的纹理特征,把这些纹理特征参量连同图像块的颜色特征和笔画特征参量输入训练好的BP神经网络,判断备选图像块是否包含文本.该方法运算简单,定位时间短.采用专用的文本定位比赛用图进行实验的结果表明,定位准确率可达到92%,召回率为87.4%.  相似文献   
37.
基于视频摘要生成技术的研究   总被引:5,自引:0,他引:5  
文章研究了标题形式摘要,故事板摘要及缩略视频摘要三种形式的摘要。充分利用各种多媒体融合分析手段,提出了视频内客判定模型。根据不同的视频分解粒度,提出了不同层次的对象重要度判定模型.生成有意义的视频摘要。设计实现了有效的视频摘要生成系统,融合多种技术与方法,形成完整的检索视频索引生成系统。  相似文献   
38.
39.
New text indexing functionalities of the compressed suffix arrays are proposed. The compressed suffix array proposed by Grossi and Vitter is a space-efficient data structure for text indexing. It occupies only O(n) bits for a text of length n; however it also uses the text itself that occupies bits for the alphabet . In this paper we modify the data structure so that pattern matching can be done without any access to the text. In addition to the original functions of the compressed suffix array, we add new operations search, decompress and inverse to the compressed suffix arrays. We show that the new index can find occ occurrences of any substring P of the text in O(|P|logn+occlogεn) time for any fixed 1ε>0 without access to the text. The index also can decompress a part of the text of length m in O(m+logεn) time. For a text of length n on an alphabet such that , our new index occupies only bits where is the order-0 entropy of the text. Especially for ε=1 the size is bits. Therefore the index will be smaller than the text, which means we can perform fast queries from compressed texts.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号