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   9904篇
  免费   81篇
  国内免费   5篇
电工技术   128篇
综合类   4篇
化学工业   416篇
金属工艺   296篇
机械仪表   69篇
建筑科学   58篇
矿业工程   1篇
能源动力   48篇
轻工业   117篇
水利工程   7篇
石油天然气   5篇
无线电   434篇
一般工业技术   252篇
冶金工业   61篇
原子能技术   93篇
自动化技术   8001篇
  2024年   1篇
  2023年   33篇
  2022年   33篇
  2021年   88篇
  2020年   57篇
  2019年   57篇
  2018年   59篇
  2017年   44篇
  2016年   86篇
  2015年   38篇
  2014年   239篇
  2013年   231篇
  2012年   828篇
  2011年   2321篇
  2010年   1143篇
  2009年   974篇
  2008年   693篇
  2007年   599篇
  2006年   454篇
  2005年   587篇
  2004年   519篇
  2003年   580篇
  2002年   276篇
  2001年   4篇
  2000年   2篇
  1999年   1篇
  1998年   3篇
  1997年   5篇
  1996年   5篇
  1995年   2篇
  1993年   4篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1977年   2篇
排序方式: 共有9990条查询结果,搜索用时 15 毫秒
91.
92.
In the last decade there was growing interest in strategic management literature about factors that influence a company's ability to use IT. There is general consensus that knowledge and competency are necessary in developing an IT capability, but there is very little understanding of what the necessary competencies are, and how they influence IS usage in different contexts. The small and medium-sized enterprise context is particularly interesting for two reasons: it constitutes a major part of the economy and it has been relatively unsuccessful in exploiting e-business.  相似文献   
93.
In this paper we consider the problem of constructing confidence regions for the parameters of nonlinear dynamical systems. The proposed method uses higher order statistics and extends the LSCR (leave-out sign-dominant correlation regions) algorithm for linear systems introduced in Campi and Weyer [2005, Guaranteed non-asymptotic confidence regions in system identification. Automatica 41(10), 1751-1764. Extended version available at 〈http://www.ing.unibs.it/∼campi〉]. The confidence regions contain the true parameter value with a guaranteed probability for any finite number of data points. Moreover, the confidence regions shrink around the true parameter value as the number of data points increases. The usefulness of the proposed approach is illustrated on some simple examples.  相似文献   
94.
The most efficient approach to a fair exchange is to use an off-line trusted third party (TTP for short) who gets involved only when a dispute between two parties occurs. However, exchanged secrets that are not protected properly may be exposed to the TTP when one of these two parties asks the TTP to mediate the dispute. The first work to protect exchanged secrets from TTP’s misuse was proposed by Franklin and Reiter in 1997. They provided an on-line semi-trusted third party instead of an off-line third party for a fair exchange. Their schemes forced the TTP to take part in the protocol for all the cases, and thus, deemed to be impractical.The present paper, introduces several models, including single and multiple TTPs, to focus the attention not only on security properties, but also on reliability functions. In the single TTP mode, our new scheme can protect the exchanged data through an efficient exchange protocol, whereas in the multiple TTP mode, we proposed an approach to balance the security level with the reliability of the system.  相似文献   
95.
Based on a polynomial operator approach, a new sparse controller structure is derived, which is actually an improved version of the recently proposed structure [Li, G. (2004). A polynomial-operator-based DFIIt structure for IIR filters. IEEE Transactions on Circuits and Systems II, 51, 147-151]. The performance of the proposed structure is analyzed by deriving the corresponding expression of roundoff noise gain and the problem of finding optimized sparse structures is solved efficiently with a genetic algorithm (GA). A numerical example is given, which shows that the newly developed structure can achieve much better performance than some well-known structures and particularly outperforms the traditional optimal fully parametrized realization greatly in terms of reducing roundoff noise and implementation complexity.  相似文献   
96.
This paper presents the physical design methodology of the VCI/SPIN wrappers. The challenge was the validation of the wrappers’ specification with Alliance CAD Tools.A wrapper is a standard gateway used by a subscriber to access an interconnect. Because there are as many wrappers as subscribers, it is relevant to have an estimation of the wrapper’s area, its frequency and then compare these results to the router’s.The interest to perform this study with academic tools is to show that commercial tools are not the unique way for experimentations.  相似文献   
97.
This paper presents a robust rule-based approach for the splitting of binary clumps that are formed by objects of diverse shapes and sizes. First, the deepest boundary pixels, i.e., the concavity pixels in a clump, are detected using a fast and accurate scheme. Next, concavity-based rules are applied to generate the candidate split lines that join pairs of concavity pixels. A figure of merit is used to determine the best split line from the set of candidate lines. Experimental results show that the proposed approach is robust and accurate.  相似文献   
98.
This paper proposes an identity-based threshold decryption scheme IB-ThDec and reduces its security to the Bilinear Diffie-Hellman problem. Compared with previous work, this conceals two pairing computations in the ciphertext validity verification procedure. The formal proof of security of this scheme is provided in the random oracle model. Additionally, we show that IB-ThDec can be applied to the threshold key escrow and the mediated cryptosystems.  相似文献   
99.
Motion vector plays one significant feature in moving object segmentation. However, the motion vector in this application is required to represent the actual motion displacement, rather than regions of visually significant similarity. In this paper, region-based selective optical flow back-projection (RSOFB) which back-projects optical flows in a region to restore the region's motion vector from gradient-based optical flows, is proposed to obtain genuine motion displacement. The back-projection is performed based on minimizing the projection mean square errors of the motion vector on gradient directions. As optical flows of various magnitudes and directions provide various degrees of reliability in the genuine motion restoration, the optical flows to be used in the RSOFB are optimally selected based on their sensitivity to noises and their tendency in causing motion estimation errors. In this paper a deterministic solution is also derived for performing the minimization and obtaining the genuine motion magnitude and motion direction.  相似文献   
100.
Fast, large-scale model predictive control by partial enumeration   总被引:1,自引:0,他引:1  
Partial enumeration (PE) is presented as a method for treating large, linear model predictive control applications that are out of reach with available MPC methods. PE uses both a table storage method and online optimization to achieve this goal. Versions of PE are shown to be closed-loop stable. PE is applied to an industrial example with more than 250 states, 32 inputs, and a 25-sample control horizon. The performance is less than 0.01% suboptimal, with average speedup factors in the range of 80-220, and worst-case speedups in the range of 4.9-39.2, compared to an existing MPC method. Small tables with only 25-200 entries were used to obtain this performance, while full enumeration is intractable for this example.  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