排序方式: 共有45条查询结果,搜索用时 625 毫秒
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教学管理是高等院校各项管理工作中的核心。随着高等教育改革和信息产业的飞速发展,特别是计算机及网络技术的广泛应用,给传统的教学管理工作带来新的挑战。为此要转变传统的教学管理理念,运用现代化的管理手段,建立现代化的教学管理机制,以提高教学管理的质量和效率,达到提高教学质量的目的。 相似文献
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舰船电子装备特点及其发展 总被引:1,自引:0,他引:1
本文阐述舰船电子装备的内涵,从技术和管理两个方面叙述舰船电子装备的特点,同时简要分析舰船电子装备的发展趋势。 相似文献
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Su-wei Wang Xiu-duo Song Zong-kai Wu Lei Xiao Guang-pu Zhang Yu-bing Hu Ga-zi Hao Wei Jiang Feng-qi Zhao 《防务技术》2021,17(6):1954-1966
The frequent occurrence of safety accidents during the calendering process is caused by the flammable and explosive properties of composite modified double-base (CMDB) propellant. Optimization of process parameters with the aid of fluid simulation technology could effectively ensure the safety of the calendering process. To improve the accuracy of the simulation results, material parameters and model structure were corrected based on actual conditions, and adaptive grid technology was applied in the local mesh refinement. In addition, the rheological behavior, motion trajectories and heat transfer mechanisms of CMDB propellant slurry were studied with different gaps, rotational rates and temperatures of two rollers. The results indicated that the refined mesh could significantly improve the contour clarity of boundaries and simulate the characteristics of CMDB propellant slurry reflux movement caused by the convergent flow near the outlet. Compared with the gap, the increased rotational rate of roller could promote the reflux movement and intensify the shear flow of slurry inside the flow region by viscous shear dragging. Meanwhile, under the synergistic effect of contact heat transfer as well as convective heat exchange, heat accumulated near the outlet and diffused along the reflux movement, which led to the countercurrent heat dissipation behavior of CMDB propellant slurry. The plasticizing mechanism of slurry and the safety of calendering under different conditions were explored, which provided theoretical guidance and reference data for the optimization of calendering process conditions. Based on the simulation results, the safety of the CMDB propellant calendering process could be significantly improved with a few tests conducted during a short research and development cycle. 相似文献
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地空导弹网络化作战系统生存能力评估 总被引:1,自引:0,他引:1
结合地空导弹网络化作战系统的实际情况,给出了影响其生存能力的指标体系,建立了合理的评估模型.利用AHP 的指数标度法和单向链法相结合的方法确定指标的权重.最后通过实例表明,利用该模型评估切实有效. 相似文献
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为了合理选择样本条件以实现高效的智能化诊断,以及克服智能化方法中传统反向传播(back propagation, BP)网络权值较多、局部信息提取能力不足的问题,对基于卷积神经网络(convolutional neural network, CNN)的开路故障诊断方法进行研究,并以典型的三相两电平逆变器为具体对象,着重分析样本时长、样本数量变化时,CNN方法相较于BP网络方法在网络权值数量、训练稳定性、诊断准确率上的量化优势。结果表明,基于CNN的方法可在权值数量远少于BP网络方法的情况下构建深度更深的诊断模型,并在更短样本时长、更少训练样本数量下实现高效、准确的开路故障诊断。 相似文献
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This paper considers the time difference of arrival (TDOA) and frequency difference of arrival (FDOA)estimation problem for joint localization using unmanned aerial vehicles (UAVs),involving range migration (RM) and Doppler ambiguity within observation interval.A robust estimation method based on interpolation and resampling is proposed.Specifically,the interpolation artificially increases the pulse repetition frequency (PRF).After that,the resampling eliminates the coupling between range frequency and slow time.Finally,a coherent integration step based on inverse discrete Fourier transform (IDFT) is used to achieve parameter estimation and suppress the grating lobes caused by interpolation.The proposed method could be efficiently implemented by fast Fourier transform (FFF),inverse FFT (IFFF) and non-uniform FFT (NUFFT) without parameter searching procedures.Numerical experiments indicate that the proposed method has nearly optimal anti-noise performance but much lower computational complexity than the maximum likelihood estimator,which makes it more competitive in practical applications. 相似文献
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