全文获取类型
收费全文 | 9298篇 |
免费 | 1350篇 |
国内免费 | 1022篇 |
专业分类
电工技术 | 444篇 |
技术理论 | 1篇 |
综合类 | 947篇 |
化学工业 | 90篇 |
金属工艺 | 95篇 |
机械仪表 | 303篇 |
建筑科学 | 282篇 |
矿业工程 | 149篇 |
能源动力 | 27篇 |
轻工业 | 51篇 |
水利工程 | 71篇 |
石油天然气 | 66篇 |
武器工业 | 58篇 |
无线电 | 3708篇 |
一般工业技术 | 289篇 |
冶金工业 | 101篇 |
原子能技术 | 20篇 |
自动化技术 | 4968篇 |
出版年
2024年 | 38篇 |
2023年 | 99篇 |
2022年 | 195篇 |
2021年 | 217篇 |
2020年 | 234篇 |
2019年 | 166篇 |
2018年 | 198篇 |
2017年 | 287篇 |
2016年 | 296篇 |
2015年 | 425篇 |
2014年 | 708篇 |
2013年 | 681篇 |
2012年 | 881篇 |
2011年 | 897篇 |
2010年 | 708篇 |
2009年 | 674篇 |
2008年 | 786篇 |
2007年 | 817篇 |
2006年 | 658篇 |
2005年 | 643篇 |
2004年 | 479篇 |
2003年 | 395篇 |
2002年 | 267篇 |
2001年 | 220篇 |
2000年 | 183篇 |
1999年 | 124篇 |
1998年 | 85篇 |
1997年 | 83篇 |
1996年 | 56篇 |
1995年 | 50篇 |
1994年 | 25篇 |
1993年 | 20篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 12篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
In this paper we combine video compression and modern image processing methods. We construct novel iterative filter methods for prediction signals based on Partial Differential Equation (PDE) based methods. The mathematical framework of the employed diffusion filter class is given and some desirable properties are stated. In particular, two types of diffusion filters are constructed: a uniform diffusion filter using a fixed filter mask and a signal adaptive diffusion filter that incorporates the structures of the underlying prediction signal. The latter has the advantage of not attenuating existing edges while the uniform filter is less complex. The filters are embedded into a software based on HEVC with additional QTBT (Quadtree plus Binary Tree) and MTT (Multi-Type-Tree) block structure. In this setting, several measures to reduce the coding complexity of the tool are introduced, discussed and tested thoroughly. The coding complexity is reduced by up to 70% while maintaining over 80% of the gain. Overall, the diffusion filter method achieves average bitrate savings of 2.27% for Random Access having an average encoder runtime complexity of 119% and 117% decoder runtime complexity. For individual test sequences, results of 7.36% for Random Access are accomplished. 相似文献
2.
3.
4.
5.
目前采用的视频流调度算法,没有充分利用补丁流满足服务率高而占用系统资源少的优势,系统效率较低.为了提高效率,提出了一种基于MFQ的补丁优先算法,并给出了该算法的系统流程。通过对实验结果的比较,该算法在用户请求撤销率、节目调度不公平性和用户等待时间方面有明显的优越性. 相似文献
6.
Sebastián López Gustavo M. Callicó Félix Tobajas Valentín de Armas José F. López Roberto Sarmiento 《ETRI Journal》2008,30(6):862-864
This letter presents a novel approach for organizing computational resources into groups within H.264/AVC motion estimation architectures, leading to reductions of up to 75% in the equivalent gate count with respect to state‐of‐the‐art designs. 相似文献
7.
8.
数字电视系统在提高图像质量方面已显示出极大的优越性。因此,世界各国电视台都已开始数字化的进程,中国也不例外。本文详细介绍了中央电视台第一个数字化演播室-800m^2演播室的视频系统,包括视频系统数字信号格式的确定,主要设备的特点以及演播室数字视频系统的主要特点等,供广大同行参考。 相似文献
9.
Sanghoon Lee Chris Podilchuk Vidhya Krishnan Alan C. Bovik 《The Journal of VLSI Signal Processing》2003,34(1-2):149-166
By exploiting new human-machine interface techniques, such as visual eyetrackers, it should be possible to develop more efficient visual multimedia services associated with low bandwidth, dynamic channel adaptation and robust visual data transmission. In this paper, we introduce foveation-based error resilience and unequal error protection techniques over highly error-prone mobile networks. Each frame is spatially divided into foveated and background layers according to perceptual importance. Perceptual importance is determined either through an eye tracker or by manually selecting a region of interest. We attempt to improve reconstructed visual quality by maintaining the high visual source throughput of the foveated layer using foveation-based error resilience and error correction using a combination of turbo codes and ARQ (automatic reQuest). In order to alleviate the degradation of visual quality, a foveation based bitstream partitioning is developed. In an effort to increase the source throughput of the foveated layer, we develop unequal delay-constrained ARQ (automatic reQuest) and rate compatible punctured turbo codes where the punctual pattern of RCPC (rate compatible punctured convolutional) codes in H.223 Annex C is used. In the simulation, the visual quality is significantly increased in the area of interest using foveation-based error resilience and unequal error protection; (as much as 3 dB FPSNR (foveal peak signal to noise ratio) improvement) at 40% packet error rate. Over real-fading statistics measured in the downtown area of Austin, Texas, the visual quality is increased up to 1.5 dB in PSNR and 1.8 dB in FPSNR at a channel SNR of 5 dB. 相似文献
10.