全文获取类型
收费全文 | 4609篇 |
免费 | 225篇 |
国内免费 | 325篇 |
专业分类
电工技术 | 95篇 |
综合类 | 230篇 |
化学工业 | 199篇 |
金属工艺 | 177篇 |
机械仪表 | 267篇 |
建筑科学 | 234篇 |
矿业工程 | 27篇 |
能源动力 | 51篇 |
轻工业 | 114篇 |
水利工程 | 8篇 |
石油天然气 | 96篇 |
武器工业 | 10篇 |
无线电 | 535篇 |
一般工业技术 | 217篇 |
冶金工业 | 16篇 |
原子能技术 | 18篇 |
自动化技术 | 2865篇 |
出版年
2023年 | 29篇 |
2022年 | 60篇 |
2021年 | 73篇 |
2020年 | 77篇 |
2019年 | 70篇 |
2018年 | 57篇 |
2017年 | 81篇 |
2016年 | 104篇 |
2015年 | 141篇 |
2014年 | 210篇 |
2013年 | 199篇 |
2012年 | 280篇 |
2011年 | 330篇 |
2010年 | 248篇 |
2009年 | 247篇 |
2008年 | 267篇 |
2007年 | 308篇 |
2006年 | 320篇 |
2005年 | 268篇 |
2004年 | 222篇 |
2003年 | 237篇 |
2002年 | 184篇 |
2001年 | 116篇 |
2000年 | 121篇 |
1999年 | 103篇 |
1998年 | 107篇 |
1997年 | 87篇 |
1996年 | 90篇 |
1995年 | 80篇 |
1994年 | 53篇 |
1993年 | 33篇 |
1992年 | 43篇 |
1991年 | 26篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 18篇 |
1983年 | 28篇 |
1982年 | 23篇 |
1981年 | 26篇 |
1980年 | 21篇 |
1979年 | 17篇 |
1978年 | 20篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1973年 | 10篇 |
排序方式: 共有5159条查询结果,搜索用时 187 毫秒
111.
An automatic road sign recognition system first locates road signs within images captured by an imaging sensor on-board of
a vehicle, and then identifies the detected road signs. This paper presents an automatic neural-network-based road sign recognition
system. First, a study of the existing road sign recognition research is presented. In this study, the issues associated with
automatic road sign recognition are described, the existing methods developed to tackle the road sign recognition problem
are reviewed, and a comparison of the features of these methods is given. Second, the developed road sign recognition system
is described. The system is capable of analysing live colour road scene images, detecting multiple road signs within each
image, and classifying the type of road signs detected. The system consists of two modules: detection and classification.
The detection module segments the input image in the hue-saturation-intensity colour space, and then detects road signs using
a Multi-layer Perceptron neural-network. The classification module determines the type of detected road signs using a series
of one to one architectural Multi-layer Perceptron neural networks. Two sets of classifiers are trained using the Resillient-Backpropagation
and Scaled-Conjugate-Gradient algorithms. The two modules of the system are evaluated individually first. Then the system
is tested as a whole. The experimental results demonstrate that the system is capable of achieving an average recognition
hit-rate of 95.96% using the scaled-conjugate-gradient trained classifiers. 相似文献
112.
该文提出一种基于多摄像机信息融合的行为识别方法。新方法使用背景融合的方式融合多镜头的信息,使用背景差分提出人体目标,基于运动惯性定律解决了多目标跟踪的问题,并在行为识别中引入了人工智能和多层次分析等先进的手段。 相似文献
113.
左旭辉 《数字社区&智能家居》2009,5(9):7073-7074
为解决行为识别中运动特征提取的问题,该文提出了一种基于三阶帧差的运动特征提取方案,用于提取运动特征中的变化大小、运动变化的一致性、运动方向的一致性等。实验证明,新方法速度快,准确度高。 相似文献
114.
115.
116.
117.
利用Visual Basic1来调用PowerPoint演示文稿中的填充效果的对象,通过对填充效果属性的分析,找到了各个属性的数值,并结合Access数据库,编写了一个"填充效果"对话框,实现了"填充"效果的设置功能。 相似文献
118.
本文应用语言模式识别的方法,对三角形语言识别模式中的等腰三角形的语言识别模型进行识别。取三角形的三条边作为特征因子集,主要根据三角形的特点建立隶属函数并给出建立隶属函数的理论依据。 相似文献
119.
Hasan Celik Alan Hanjalic Emile A. Hendriks 《Computer Vision and Image Understanding》2009,113(10):1076-1094
Object detection is an essential component in automated vision-based surveillance systems. In general, object detectors are constructed using training examples obtained from large annotated data sets. The inevitable limitations of typical training data sets make such supervised methods unsuitable for building generic surveillance systems applicable to a wide variety of scenes and camera setups. In our previous work we proposed an unsupervised method for learning and detecting the dominant object class in a general dynamic scene observed by a static camera. In this paper, we investigate the possibilities to expand the applicability of this method to the problem of multiple dominant object classes. We propose an idea on how to approach this expansion, and perform an evaluation of this idea using two representative surveillance video sequences. 相似文献
120.
Robert Jay Milewski Venu Govindaraju Anurag Bhardwaj 《International Journal on Document Analysis and Recognition》2009,11(4):203-218
A new paradigm, which models the relationships between handwriting and topic categories, in the context of medical forms,
is presented. The ultimate goals are: (1) a robust method which categorizes medical forms into specified categories, and (2)
the use of such information for practical applications such as an improved recognition of medical handwriting or retrieval
of medical forms as in a search engine. Medical forms have diverse, complex and large lexicons consisting of English, Medical
and Pharmacology corpus. Our technique shows that a few recognized characters, returned by handwriting recognition, can be
used to construct a linguistic model capable of representing a medical topic category. This allows (1) a reduced lexicon to
be constructed, thereby improving handwriting recognition performance, and (2) PCR (Pre-Hospital Care Report) forms to be
tagged with a topic category and subsequently searched by information retrieval systems. We present an improvement of over
7% in raw recognition rate and a mean average precision of 0.28 over a set of 1,175 queries on a data set of unconstrained
handwritten medical forms filled in emergency environments.
This work was supported by the National Science Foundation. 相似文献