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   10657篇
  国内免费   267篇
  完全免费   3616篇
  自动化技术   14540篇
  2020年   10篇
  2019年   49篇
  2018年   338篇
  2017年   373篇
  2016年   360篇
  2015年   425篇
  2014年   667篇
  2013年   691篇
  2012年   1202篇
  2011年   1531篇
  2010年   1311篇
  2009年   1477篇
  2008年   1307篇
  2007年   1165篇
  2006年   1014篇
  2005年   476篇
  2004年   354篇
  2003年   300篇
  2002年   228篇
  2001年   157篇
  2000年   148篇
  1999年   133篇
  1998年   113篇
  1997年   82篇
  1996年   71篇
  1995年   48篇
  1994年   55篇
  1993年   60篇
  1992年   47篇
  1991年   41篇
  1990年   33篇
  1989年   32篇
  1988年   23篇
  1987年   29篇
  1986年   28篇
  1985年   15篇
  1984年   15篇
  1983年   9篇
  1982年   6篇
  1981年   7篇
  1980年   6篇
  1979年   12篇
  1978年   10篇
  1977年   12篇
  1976年   15篇
  1975年   7篇
  1974年   9篇
  1973年   12篇
  1972年   2篇
  1971年   5篇
  1970年   6篇
  1969年   2篇
  1967年   4篇
  1966年   1篇
  1964年   2篇
  1963年   3篇
  1962年   1篇
  1959年   1篇
排序方式: 共有14540条查询结果,搜索用时 46 毫秒
1.
Induction of decision trees   总被引:322,自引:2,他引:320  
The technology for building knowledge-based systems by inductive inference from examples has been demonstrated successfully in several practical applications. This paper summarizes an approach to synthesizing decision trees that has been used in a variety of systems, and it describes one such system, ID3, in detail. Results from recent studies show ways in which the methodology can be modified to deal with information that is noisy and/or incomplete. A reported shortcoming of the basic algorithm is discussed and two means of overcoming it are compared. The paper concludes with illustrations of current research directions.  相似文献
2.
数学形态学在图象处理中的应用进展   总被引:43,自引:0,他引:43       下载免费PDF全文
数学形态学是一种非线性滤波方法,形态和差运算,即膨胀与腐蚀是数学形态学的基础,数学形态学已由二值形态学、灰度形态软数学形态学、模糊形态学发展到模糊软形态学,可用于抑制噪声、特征提取、边缘检测、图象分割、形状识别,纹理分析、图象恢复与重建等图象处理问题,在图象处理领域得到了越来越广泛的应用,本文结合目前的研究进展,对数学形态学的理论研究及其应用进展进行综述性阐述。  相似文献
3.
一种基于小波与形态学的车牌图象分割方法   总被引:42,自引:2,他引:40  
针对汽车车牌与车身背景的分割问题,给出了一种基于小波分析和数学形态学的图象分割方法。该方法是通过小波多尺度分解提取出纺理清晰,具有不同空间分辨率、不同方向的边缘子图象。其水平方向低频、垂直方向高频的这一细节分量,主要代表车牌的目标区域。然后,用数学形态学方法对小波分解后的细节图象进行一系列的形态运算,进一步消除无用信息和噪声,以找准车牌位置。用该方法对在不同照明条件下所采集到的一系列车头、车尾图象  相似文献
4.
基于SUMO的概念语义相似度研究   总被引:33,自引:4,他引:29       下载免费PDF全文
SUMO(建议上层共享知识本体)是由IEEE标准上层知识本体工作小组所建置的,其目的是发展标准的上层知识本体,这将促进数据互通性、信息搜寻和检索、自动推理和自然语言处理。基于该共享知识本体,提出了一种计算两概念语义相似度的方法。根据该方法实现了一个计算程序模块,并将计算结果同人类的主观判断进行了比较,验证了该方法的有效性。该研究工作可以在面向Web的知识检索领域中得到应用,还可以为本体的相关研究提供一定的理论基础。  相似文献
5.
A new evolutionary system for evolving artificial neural networks   总被引:32,自引:0,他引:32  
This paper presents a new evolutionary system, i.e., EPNet, for evolving artificial neural networks (ANNs). The evolutionary algorithm used in EPNet is based on Fogel's evolutionary programming (EP). Unlike most previous studies on evolving ANN's, this paper puts its emphasis on evolving ANN's behaviors. Five mutation operators proposed in EPNet reflect such an emphasis on evolving behaviors. Close behavioral links between parents and their offspring are maintained by various mutations, such as partial training and node splitting. EPNet evolves ANN's architectures and connection weights (including biases) simultaneously in order to reduce the noise in fitness evaluation. The parsimony of evolved ANN's is encouraged by preferring node/connection deletion to addition. EPNet has been tested on a number of benchmark problems in machine learning and ANNs, such as the parity problem, the medical diagnosis problems, the Australian credit card assessment problem, and the Mackey-Glass time series prediction problem. The experimental results show that EPNet can produce very compact ANNs with good generalization ability in comparison with other algorithms.  相似文献
6.
局部快速微调遗传算法   总被引:31,自引:1,他引:30  
给出了一种进行局部快速微调的遗传算法——在变异中,将适应值高的个体和适应值低的个体分别进行诱导和随机动态区域变异;在交叉操作中,划分为搜索阶段和微调阶段,分别采用随机线性交叉和部分确定性诱导交叉.应用该算法对全局最优解邻域进行搜索,能在较短的时间内找到高精度的数值解.对10个典型测试函数优化问题的实验表明,该方法具有快速、稳定和易于实现的优点.如果合理调整控制参数,其全局搜索的收敛速度和解的质量明显优于传统GA.  相似文献
7.
Constructing support vector machine ensemble   总被引:30,自引:0,他引:30  
Hyun-Chul  Shaoning  Hong-Mo  Daijin  Sung 《Pattern Recognition》2003,36(12):2757-2767
Even the support vector machine (SVM) has been proposed to provide a good generalization performance, the classification result of the practically implemented SVM is often far from the theoretically expected level because their implementations are based on the approximated algorithms due to the high complexity of time and space. To improve the limited classification performance of the real SVM, we propose to use the SVM ensemble with bagging (bootstrap aggregating) or boosting. In bagging, each individual SVM is trained independently using the randomly chosen training samples via a bootstrap technique. In boosting, each individual SVM is trained using the training samples chosen according to the sample's probability distribution that is updated in proportional to the errorness of the sample. In both bagging and boosting, the trained individual SVMs are aggregated to make a collective decision in several ways such as the majority voting, least-squares estimation-based weighting, and the double-layer hierarchical combining. Various simulation results for the IRIS data classification and the hand-written digit recognition, and the fraud detection show that the proposed SVM ensemble with bagging or boosting outperforms a single SVM in terms of classification accuracy greatly.  相似文献
8.
Combination of multiple classifiers using local accuracy estimates   总被引:27,自引:0,他引:27  
This paper presents a method for combining classifiers that uses estimates of each individual classifier's local accuracy in small regions of feature space surrounding an unknown test sample. An empirical evaluation using five real data sets confirms the validity of our approach compared to some other combination of multiple classifiers algorithms. We also suggest a methodology for determining the best mix of individual classifiers  相似文献
9.
Salinization is a major cause of soil degradation in the Murray–Darling Basin of Australia. The objective of this research is to evaluate the utility of field-derived spectra of saline soils and related vegetation for characterizing and mapping the spatial distribution of irrigation-induced soil salinization. A FieldSpec FR hand-held spectrometer was used to measure the spectra of a range of salinized soils and associated vegetation. Strategies for mapping field-derived spectra using hyperspectral (HyMap) imagery were assessed, and a continuum-removed Spectral-Feature-Fitting (SFF) approach adopted. Field-derived spectra of the vegetation comprising of samphire, sea blite, and native grass species are also useful indicators of salinization; however, their absence is not necessarily an indicator of healthy soils. Distribution maps created using the SFF method and a restricted wavelength range of field-derived spectra provide an accurate record of the distribution of both vegetation and soil indicators of salinization at the time of image acquisition. Salinized soil and vegetation indicator class maps show a similar spatial distribution to soil salinization as mapped by ground-based geophysical surveys.  相似文献
10.
焦炉配煤专家系统的定性定量综合设计方法   总被引:26,自引:1,他引:25       下载免费PDF全文
焦炉配煤炼焦过程是存在诸多不确定性、无法用数学模型描述的复杂工业过程,传 统控制方法难以实施控制.根据焦化理论和生产所获工业数据构造数学模型,以群体专家经 验得到的定性知识构成规则模型,将解析的数学模型与基于知识的规则模型相结合,采用定 性定量综合集成方法,建立焦炭质量预测模型,提出了配煤比计算的实用算法,并实时控制配 煤流量.系统于1994年正式投入工厂运行,焦炭质量预测精度达到95%,配煤准确率达到 97%.工业运行结果证明了方法的有效性.  相似文献
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