收费全文 | 110361篇 |
免费 | 8232篇 |
国内免费 | 4138篇 |
电工技术 | 5791篇 |
技术理论 | 11篇 |
综合类 | 6576篇 |
化学工业 | 18387篇 |
金属工艺 | 5764篇 |
机械仪表 | 6709篇 |
建筑科学 | 8577篇 |
矿业工程 | 3048篇 |
能源动力 | 3091篇 |
轻工业 | 6616篇 |
水利工程 | 1697篇 |
石油天然气 | 6149篇 |
武器工业 | 695篇 |
无线电 | 13881篇 |
一般工业技术 | 14111篇 |
冶金工业 | 5718篇 |
原子能技术 | 1240篇 |
自动化技术 | 14670篇 |
2024年 | 296篇 |
2023年 | 1662篇 |
2022年 | 2256篇 |
2021年 | 3801篇 |
2020年 | 2977篇 |
2019年 | 2528篇 |
2018年 | 2937篇 |
2017年 | 3321篇 |
2016年 | 2900篇 |
2015年 | 3833篇 |
2014年 | 4885篇 |
2013年 | 6244篇 |
2012年 | 6580篇 |
2011年 | 7192篇 |
2010年 | 6267篇 |
2009年 | 6189篇 |
2008年 | 6173篇 |
2007年 | 5764篇 |
2006年 | 6047篇 |
2005年 | 5421篇 |
2004年 | 3695篇 |
2003年 | 3202篇 |
2002年 | 2858篇 |
2001年 | 2758篇 |
2000年 | 2875篇 |
1999年 | 3373篇 |
1998年 | 2901篇 |
1997年 | 2534篇 |
1996年 | 2274篇 |
1995年 | 1904篇 |
1994年 | 1526篇 |
1993年 | 1210篇 |
1992年 | 956篇 |
1991年 | 726篇 |
1990年 | 589篇 |
1989年 | 489篇 |
1988年 | 380篇 |
1987年 | 286篇 |
1986年 | 194篇 |
1985年 | 166篇 |
1984年 | 94篇 |
1983年 | 77篇 |
1982年 | 87篇 |
1981年 | 57篇 |
1980年 | 44篇 |
1979年 | 32篇 |
1978年 | 24篇 |
1977年 | 25篇 |
1976年 | 40篇 |
1973年 | 11篇 |
We propose a novel online multiple object tracker taking structure information into account. State-of-the-art multi-object tracking (MOT) approaches commonly focus on discriminative appearance features, while neglect in different levels structure information and the core of data association. Addressing this, we design a new tracker fully exploiting structure information and encoding such information into the cost function of the graph matching model. Firstly, a new measurement is proposed to compare the structure similarity of two graphs whose nodes are equal. With this measurement, we define a complete matching which performs association in high efficiency. Secondly, for incomplete matching scenarios, a structure keeper net (SKnet) is designed to adaptively establish the graph for matching. Finally, we conduct extensive experiments on benchmarks including MOT2015 and MOT17. The results demonstrate the competitiveness and practicability of our tracker.
相似文献Since the time series data have the characteristics of a large amount of data and non-stationarity, we usually cannot obtain a satisfactory result by a single-model-based method to detect anomalies in time series data. To overcome this problem, in this paper, a combination-model-based approach is proposed by combining a similarity-measurement-based method and a model-based method for anomaly detection. First, the process of data representation is performed to generate a new data form to arrive at the purpose of reducing data volume. Furthermore, due to the anomalies being generally caused by changes in amplitude and shape, we take both the original time series data and their amplitude change data into consideration of the process of data representation to capture the shape and morphological features. Then, the results of data representation are employed to establish a model for anomaly detection. Compared with the state-of-the-art methods, experimental studies on a large number of datasets show that the proposed method can significantly improve the performance of anomaly detection with higher data anomaly resolution.
相似文献This paper extends the quadrature method to price exotic options under jump-diffusion models. We compute the transition density of jump-extended models using convolution integrals. Furthermore, a simpler and more efficient lattice grid is introduced to implement the recursion more directly in matrix form. It can be shown that a lot of running time can be saved. At last, we apply the developed approach to the different jump-extended models to demonstrate its universality and provide a detailed comparison for the discrete path-dependent options to demonstrate its advantages in terms of speed and accuracy.
相似文献