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   296篇
  免费   19篇
  国内免费   20篇
电工技术   5篇
综合类   8篇
化学工业   5篇
金属工艺   74篇
机械仪表   37篇
建筑科学   2篇
矿业工程   3篇
能源动力   2篇
轻工业   1篇
石油天然气   16篇
武器工业   1篇
无线电   17篇
一般工业技术   56篇
冶金工业   9篇
自动化技术   99篇
  2022年   5篇
  2021年   7篇
  2020年   12篇
  2019年   4篇
  2018年   5篇
  2017年   3篇
  2016年   8篇
  2015年   6篇
  2014年   12篇
  2013年   17篇
  2012年   16篇
  2011年   32篇
  2010年   15篇
  2009年   16篇
  2008年   13篇
  2007年   24篇
  2006年   22篇
  2005年   15篇
  2004年   17篇
  2003年   14篇
  2002年   9篇
  2001年   9篇
  2000年   12篇
  1999年   9篇
  1998年   11篇
  1997年   6篇
  1996年   6篇
  1995年   6篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1988年   1篇
排序方式: 共有335条查询结果,搜索用时 15 毫秒
1.
In this paper, we present an approach toward pedestrian detection and tracking from infrared imagery using joint shape and appearance cues. A layered representation is first introduced and a generalized expectation-maximization (EM) algorithm is developed to separate infrared images into background (still) and foreground (moving) layers regardless of camera panning. In the two-pass scheme of detecting pedestrians from the foreground layer: shape cue is first used to eliminate non-pedestrian moving objects and then appearance cue helps to locate the exact position of pedestrians. Templates with varying sizes are sequentially applied to detect pedestrians at multiple scales to accommodate different camera distances. To facilitate the task of pedestrian tracking, we formulate the problem of shot segmentation and present a graph matching-based tracking algorithm that jointly exploits the shape, appearance and distance information. Experimental results with both OSU Infrared Image Database and WVU Infrared Video Database are reported to demonstrate the accuracy and robustness of our algorithm.  相似文献   
2.
刘祖林  李华飞 《特殊钢》1996,17(5):23-25
研究了55SiMnVB弹簧钢板疲劳断口特征及裂扩展过程。结果表明,喷丸强化在表层产生的残余压应力可明显提高疲劳抗力,增强裂纹闭合效应,降低裂纹扩展速度。  相似文献   
3.
提供了新型抛丸器气力喂丸机装置的结构、设计参数发现场应用情况。该装置长期应用于六工位半自动抛丸机。现场使用表明,气力喂丸装置适用于高效抛丸器。  相似文献   
4.
钢丸增强ZA27复合材料的制备与摩擦磨损特性   总被引:2,自引:0,他引:2  
采用搅溶加压铸造研制了钢丸增强ZA27复合材料(ZSC),复合工艺简便,ZSC组织致密,钢丸与基体呈冶金结合,切削加工性能良好;在干摩擦和油润条件下,ZSC的耐磨性随钢丸量的增加而增加,并优于相同试验条件下的ZA27合金;干摩擦下ZSC具有自润滑能力和良好的耐磨减摩性能,油润下随滑动速度和载荷的增大其耐磨性较ZA27更具优势。  相似文献   
5.
通过对Q365抛丸清理室的改造,增加抛丸头,提高了清砂质量及效率,进一步改善了铸件的外观质量.  相似文献   
6.
A numerical modelling approach capable of simulating Shot Peening (SP) processes of industrial interest was developed by combining the Discrete Element Method (DEM) with the Finite Element Method (FEM).In this approach, shot–shot and shot–target interactions as well as the overall shot flow were simulated efficiently using rigid body dynamics. A new algorithm to dynamically adapt the coefficient of restitution (CoR) for repeated impacts of shots on the same spot was implemented in the DEM code to take into account the effect of material hardening. Then, a parametric study was conducted using the Finite Element Method (FEM) to investigate the influence of the SP parameters on the development of residual stresses.Finally, a two-step coupling method is presented to combine the output of DEM simulation with FEM analyses to retrieve the Compressive Residual Stresses (CRS) after multiple impacts with the aim to evaluate the minimum area required to be modelled to realistically capture the field of residual stresses. A series of such coupled analyses were performed to determine the effect of peening angle and the combination of initial velocity and mass flow rate on CRS.  相似文献   
7.
图象和视频的检索技术   总被引:10,自引:0,他引:10  
随着网络技术的发展,多媒体数据将成为网络服务的主要内容,因此对多媒体数据管理问题的研究成为近几年的热点。由于媒体信息表现性质的不同,传统关系数据库的检索方式不再适用于图象和视频,因此,必须采用基于自身内容的检索方式。文章对基于内容的图象和视频检索技术分不同层次进行了全面的总结,内容包括依据基本特征,色彩、纹理、形状、和位置关系的技术,视频的场景分割、关键帧提取技术以及基于声音、文字的检索技术等,并阐述了各种方法的优缺点,现状及发展方向。  相似文献   
8.
Easy-to-use audio/video authoring tools play a crucial role in moving multimedia software from research curiosity to mainstream applications. However, research in multimedia authoring systems has rarely been documented in the literature. This paper describes the design and implementation of an interactive video authoring system called Zodiac, which employs an innovative edit history abstraction to support several unique editing features not found in existing commercial and research video editing systems. Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among versions of authored documents. In addition, by analyzing the edit history, Zodiac is able to reliably detect a composed video stream's shot and scene boundaries, which facilitates interactive video browsing. Zodiac also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could be text, image, audio, or video. Zodiac is built on top of MMFS, a file system specifically designed for interactive multimedia development environments, and implements an internal buffer manager that supports transparent lossless compression/decompression. Shot/scene detection, video object annotation, and buffer management all exploit the edit history information for performance optimization.  相似文献   
9.
Metrics for shot boundary detection in digital video sequences   总被引:5,自引:0,他引:5  
The detection of shot boundaries in video sequences is an important task for generating indexed video databases. This paper provides a comprehensive quantitative comparison of the metrics that have been applied to shot boundary detection. In addition, several standardized statistical tests that have not been applied to this problem, as well as three new metrics, are considered. A mathematical framework for quantitatively comparing metrics is supplied. Experimental results based on a video database containing 39,000 frames are included.  相似文献   
10.
In this paper, we propose an innovative architecture to segment a news video into the so-called “stories” by both using the included video and audio information. Segmentation of news into stories is one of the key issues for achieving efficient treatment of news-based digital libraries. While the relevance of this research problem is widely recognized in the scientific community, we are in presence of a few established solutions in the field. In our approach, the segmentation is performed in two steps: first, shots are classified by combining three different anchor shot detection algorithms using video information only. Then, the shot classification is improved by using a novel anchor shot detection method based on features extracted from the audio track. Tests on a large database confirm that the proposed system outperforms each single video-based method as well as their combination.
Mario VentoEmail:
  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