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101.
随着视频监控系统的大规模普及,视频监控系统的效用评价成为一个重要的研究课题.当前视频监控系统评价只考虑了摄像机的覆盖率,缺少对摄像机覆盖质量的量化评价.该文提出了一种基于深度卷积神经网络的监控摄像机覆盖质量评价算法.将摄像机覆盖质量评价问题转化为对摄像机所采集视频帧的质量评价问题,探讨了基于视频帧的摄像机覆盖质量等级的分级策略,标注了一个摄像机视频帧质量等级数据集; 设计了一种新颖的多维标签赋值方法,利用深度卷积网络学习鲁棒的视频帧表示,进一步基于支持向量回归机(SVR)学习视频质量回归函数,从而实现对摄像机覆盖质量的鲁棒估计.实验结果表明:该算法能够准确地对监控摄像机的覆盖质量进行自动评测,有效监测了摄像机监控质量的实时变化. 相似文献
102.
The hardness, elastic modulus, and scratch resistance of a glass-ceramic rigid substrate were measured by nanoindentation and nanoscratch, and the fracture toughness was measured by indentation using a Vickers indenter. The results show that the hardness and elastic modulus at a peak indentation depth of 200 nm are 9.04 and 94.70 GPa, respectively. These values reflect the properties of the glass-ceramic rigid substrate. The fracture toughness value of the glass-ceramic rigid substrate is 2.63 MPa·m1/2. The material removal mechanisms are seen to be directly related to normal force on the tip. The critical load and scratch depth estimated from the scratch depth profile after scratching and the friction profile are 268.60 mN and 335.10 nm, respectively. If the load and scratch depth are under the critical values, the glass-ceramic rigid substrate will undergo plastic flow rather than fracture. The formula of critical depth of cut described by Bifnao et al. is modified based on the difference of critical scratch depth 相似文献
103.
JinPing Wang YangBin Li Lin Kang Yu Wang YangYin Zhong Min Liang Jian Chen ChunHai Cao WeiWei Xu PeiHeng Wu 《科学通报(英文版)》2009,54(12):2013-2017
This paper describes the design and fabrication of superconducting hot electron bolometer (HEB) mixer based on ultra-thin superconducting NbN films. The high quality films were epitaxially grown on high resistance Si substrates. The device was fabricated by magnetron sputtering, electron beam lithography (EBL), reactive ion etching (RIE), lithography, and so on. The device's resistance-temperature (R-T) curves and current-voltage (I-V) curves were studied. The results of THz response of the device are presented. Y-factor technique was used to measure the device's noise temperature. When the device was irradiated with a laser radiation of 2.5 THz, the obtained lowest noise temperature of the device was 2213 K. 相似文献
104.
Development of a middle and low latitude theoretical ionospheric model and an observation system data assimilation experiment 总被引:3,自引:0,他引:3
On the basis of previous work, we develop a middle and low latitude theoretical ionospheric model in this paper, named Theoretical Ionospheric Model of the Earth in the Institute of Geology and Geophysics, Chinese Academy of Sciences (TIME-IGGCAS). TIME-IGGCAS solves the equations of mass continuity, motion and energy of electron and ions self-consistently and uses an eccentric dipole field approximation to the Earth's magnetic field. We combine the Eulerian and Lagrangian approaches in the model and take account of the plasma ExB drift velocity. Calculation results reveal that the model is steady and credible and can reproduce most large-scale features of ionosphere. By using TIME-IGGCAS, we carried out an observation system data assimilation experiment. Assimilation results show that the ExB drift velocity can be accurately estimated by ingesting the observed foF2 and hmF2 into the model applying nonlinear least-square fit method. We suggest that this work is of great significance in the development of ionospheric data assimilation model to give better nowcast and forecast of ionosphere. 相似文献
105.
TANG Chunming 《武汉大学学报:自然科学英文版》2007,12(1):121-125
In this paper, we present an improved identity-based society oriented signature scheme with anonymous signers, which satisfies: (1) when members leave or join an organization, the public verification key and the signature verification procedure are unchanged; (2) a user participates in several organizations at the same time, her secret key is only related with her identity. However, no previous schemes have these two properties. 相似文献
106.
洪勇 《吉林大学学报(理学版)》2009,47(6):1130-1134
设||x||λ=(xλ1+xλ2+…+xλn)1/λ(x∈Rn+), ω(x)是非负可测函数, 定义带参数r的从Lp(Rn+,ω(x))到Lp(Rm+)的Hardy的Hardy型奇异积分算子Tr利用权函数方法, 讨论了Tr的(p,p)型范数, 并得到其范数的参数表达式. 相似文献
107.
108.
以株洲体育场馆为研究对象,进行了粘性流场的数值模拟,比较了屋盖升力系数和流场细节,将数值模拟结果和试验结果进行了分析,结果令人满意,特别是基于整个雨篷屋面的体形系数吻合的更好.本文还针对株洲体育中心复杂外形几何特点,构造了特定网格拓扑结构,使用分块结构化网格对该建筑进行数值模拟.模拟结果和试验数据以及涡方法的数值方法结果进行比较,结果表明可以解决具有复杂外形三维建筑物气动力学设计问题,具有较好的计算精度. 相似文献
109.
A new type of sensor with the flexible substrate is introduced. It is applicable in measuring instantaneous heat flux on the
model surface in a hypersonic shock tunnel. The working principle, structure and manufacture process of the sensor are presented.
The substrate thickness and the dynamic response parameter of the sensor are calculated. Because this sensor was successfully
used in measuring the instantaneous heat flux on the surface of a flat plate in a detonation-driven shock tunnel, it may be
effective in measuring instantaneous heat flux on the model surface. 相似文献
110.
HE XiuBin XU Bei YUAN ZhiYun 《科学通报(英文版)》2007,52(4):504-511
C-isotope analysis of the carbonates in the Upper Neoproterozoic in Keping, Xinjiang indicates that the Qigebrak Formation and the Upper Sugaitbrak Formation mainly record positive C-isotope values, and a distinct positive excursion occurs in the lower part of the Qigebrak Formation. There are three negative excursions in the boundary between the Qigebrak Formation and the Cambrian, the uppermost and lowermost Upper Sugaitbrak Formation. These characters resemble those of the Upper Neoproterozoic in the Three-Gorge area, which suggests that the Upper Sugaitbrak Formation and Qigebrak Formation can be correlated with the middle and upper parts of the Doushantuo Formation and Dengying Formation, respectively. The negative excursion at the top of the Upper Sugaitbrak Formation corresponds to that at the top of the Doushantuo Formation, while the negative excursion at the bottom of the Sugaitbrak Formation can be correlated with that at the middle part of the Doushantuo Formation in the Three-Gorge area and that at the top of the Hangelchaok diamictites in the Quruqtagh area. 相似文献