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   3128篇
  免费   476篇
  国内免费   430篇
电工技术   298篇
综合类   320篇
化学工业   194篇
金属工艺   87篇
机械仪表   239篇
建筑科学   101篇
矿业工程   99篇
能源动力   123篇
轻工业   77篇
水利工程   48篇
石油天然气   37篇
武器工业   30篇
无线电   350篇
一般工业技术   204篇
冶金工业   30篇
原子能技术   10篇
自动化技术   1787篇
  2024年   4篇
  2023年   53篇
  2022年   68篇
  2021年   87篇
  2020年   121篇
  2019年   103篇
  2018年   88篇
  2017年   119篇
  2016年   100篇
  2015年   152篇
  2014年   195篇
  2013年   224篇
  2012年   217篇
  2011年   257篇
  2010年   190篇
  2009年   208篇
  2008年   239篇
  2007年   289篇
  2006年   266篇
  2005年   228篇
  2004年   170篇
  2003年   121篇
  2002年   123篇
  2001年   87篇
  2000年   65篇
  1999年   83篇
  1998年   49篇
  1997年   44篇
  1996年   22篇
  1995年   23篇
  1994年   2篇
  1993年   4篇
  1992年   2篇
  1991年   2篇
  1990年   3篇
  1989年   6篇
  1988年   4篇
  1987年   1篇
  1986年   1篇
  1984年   4篇
  1983年   5篇
  1981年   1篇
  1980年   3篇
  1977年   1篇
排序方式: 共有4034条查询结果,搜索用时 31 毫秒
81.
Crowd management becomes a global concern due to increased population in urban areas. Better management of pedestrians leads to improved use of public places. Behavior of pedestrian’s is a major factor of crowd management in public places. There are multiple applications available in this area but the challenge is open due to complexity of crowd and depends on the environment. In this paper, we have proposed a new method for pedestrian’s behavior detection. Kalman filter has been used to detect pedestrian’s using movement based approach. Next, we have performed occlusion detection and removal using region shrinking method to isolate occluded humans. Human verification is performed on each human silhouette and wavelet analysis and particle gradient motion are extracted for each silhouettes. Gray Wolf Optimizer (GWO) has been utilized to optimize feature set and then behavior classification has been performed using the Extreme Gradient (XG) Boost classifier. Performance has been evaluated using pedestrian’s data from avenue and UBI-Fight datasets, where both have different environment. The mean achieved accuracies are 91.3% and 85.14% over the Avenue and UBI-Fight datasets, respectively. These results are more accurate as compared to other existing methods.  相似文献   
82.
Diabetic retinopathy (DR) and Diabetic Macular Edema (DME) are severe diseases that affect the eyes due to damage in blood vessels. Computer-aided automated grading will help clinicians conduct disease diagnoses at ease. Experiments of automated image processing with deep learning techniques using CNN produce promising results, especially in the medical imaging domain. However, the disease grading tasks in retinal images using CNN struggle to retain high-quality information at the output. A novel deep learning model based on variational auto-encoder to grade DR and DME abnormalities in retinal images is proposed. The objective of the proposed model is to extract the most relevant retinal image features efficiently. It focuses on addressing less relevant candidate region generation and translational invariance present in images. The experiments are conducted in IDRID dataset and evaluated using accuracy, U-kappa, sensitivity, specificity and precision metrics. The results outperform compared with other state-of-art techniques.  相似文献   
83.
The particle classifiers with three rotary cages have significant advantage in powder handling capacity. The flow field inside the classifiers were investigated from the perspective of vortex using Q criterion. Formation process and distribution of the vortices were intuitively exhibited. Structure of the guide cone was further optimized, and the classifying performance of the classifiers was evaluated. The results show that complex vortex structures were formed inside the classifier. The large-scale columnar vortex under the guide cone oscillates irregularly. This unwanted vortex is eliminated by extending the guide cone. The structure of the guide cone has little effect on the cut size, but the optimized guide cone with the long cylinder and cone significantly enhances the separation degree of the fine and coarse particles. The classifier obtains finer silica powder with a median size of 2.5 μm and higher Newton efficiency about 71.5%.  相似文献   
84.
Up-to-date skin detection techniques use adaptive skin color modeling to overcome the varying skin color problem. Most methods for tracking skin regions in videos utilize the correlation between contiguous frames. This paper proposes a new approach for detecting skin in a single image. This approach uses a local skin model to shift a globally trained skin model to adapt the final skin model to the current image. Experimental results show that the proposed method can achieve better accuracy. Two improvements for speeding up the processing are also discussed.  相似文献   
85.
汉字识别方法综述   总被引:2,自引:0,他引:2       下载免费PDF全文
孙华  张航 《计算机工程》2010,36(20):194-197
分析汉字结构特征及其演变,在汉字字库及汉字识别目标变化的基础上,结合汉字识别过程,研究与比较贝叶斯决策、二次判别函数法、隐马尔科夫模型、神经网络分类器以及支持向量机这5种汉字识别方法的优缺点及适用范围。结果表明,汉字识别方法仍需要在识别目标及特征提取、训练字符集准备方面进行改进。  相似文献   
86.
基于网格的混合神经网络计算平台研究与实现   总被引:1,自引:0,他引:1  
为了模仿人脑的复杂功能,把各种相关类型的神经网络组织起来,形成一个大规模混合神经网络.根据此需求,使用自主研发的LabGrid技术开发了一个基于网格的混合神经网络计算平台,利用该平台设计了一种新的混合神经网络分类系统来对该平台进行测试.测试结果表明,该平台具有较高的效率和良好的容错性.与其它分类系统比较可知,该分类系统有较高的准确率,从而证明了模仿人脑建立大规模混合神经网络分类系统的可行性和有效性.  相似文献   
87.
基于模糊控制的驾驶疲劳检测   总被引:1,自引:1,他引:0  
提出了一种判断疲劳程度的新方法,通过检测眼睛、嘴巴状态和头部位置等能够反应疲劳的生理特征,利用模糊控制器推理,得到人的疲劳状态的数值表示,改善了疲劳或者非疲劳的二值表示形式.通过肤色识别和阚值选取等方法得到人眼检测,进行边界提取的结果优于边缘检测.利用fisher线性分类器进行嘴唇和肤色的分类,提高了检测速度.模糊推理更精确的反应了人的疲劳程度,实验结果表明了检测方法的有效性和可信性.  相似文献   
88.
针对复杂背景条件下人脸检测的检测率低、速度慢的问题,提出了一种改进的AdaBoost算法,与遗传算法相结合,产生了一种识别率高、泛化能力好的强分类器,文中称之为GA-AdaBoost算法。该算法首先训练多个支持向量机作为弱分类器,然后用AdaBoost算法将多个弱分类器组合成一个强分类器,在组合的同时采用遗传算法对各弱分类器的权值进行全局寻优。最后,通过试验与传统AdaBoost进行对比,表明了该算法具有识别率高和速度快的优越性。  相似文献   
89.
Abstract: The paper presents a novel machine learning algorithm used for training a compound classifier system that consists of a set of area classifiers. Area classifiers recognize objects derived from the respective competence area. Splitting feature space into areas and selecting area classifiers are two key processes of the algorithm; both take place simultaneously in the course of an optimization process aimed at maximizing the system performance. An evolutionary algorithm is used to find the optimal solution. A number of experiments have been carried out to evaluate system performance. The results prove that the proposed method outperforms each elementary classifier as well as simple voting.  相似文献   
90.
基于改进联合模型的人脸表情识别   总被引:3,自引:0,他引:3       下载免费PDF全文
赵浩  吴小俊 《计算机工程》2010,36(6):206-209
在联合主动表观模型和主动形状模型的基础上,充分挖掘标定点之间的联系,提出一种局部纹理模型构建方法。通过改进匹配算法提高特征点的定位精度和匹配速度。将该算法提取到的人脸表情特征输入最近邻分类器,分类结果表明其识别率较高。  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