共查询到20条相似文献,搜索用时 15 毫秒
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田开让 《电子产品可靠性与环境试验》2000,(4):25-27
可靠性增长有两种方式:一种是自然增长,另一种是计划增长。前者是不与可靠性目标值相联系的增长方式;后者是受可靠性目标值制约的增长方式。讨论了自然增长和计划增长的概念、内涵和特点,并举例阐述了二者之间的本质区别。 相似文献
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线性变换有源CC滤波器的实现 总被引:2,自引:0,他引:2
本文研究了应用第二代电流传送器(CCII+)实现线性变换(LT)有源滤波器,基于线性变换,给出了实现电流传送器(CCII+)滤波器的两个系统设计简表。应用此设计简表能方便地综合设计全极点与椭圆点滤波器。作为例子,文中实现了一个新的三阶椭圆低通滤波器,模拟仿真结果与理论分析吻合。 相似文献
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综述了活性法陶瓷-金属封接工艺的新进展,强调指出:返烧经研磨的瓷件,用活性法同样可以得到高质量的陶瓷-金属封接件。 相似文献
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Greve A. Karcher H.J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2009,97(8):1412-1420
A radio telescope is a flexible structure under the influence of gravity, temperature, and wind. Even after all passive means of telescope construction have been applied, the residual structural deformations of a high precision telescope may still lead to focus, pointing, and path-length errors and a loss in gain that exceed the performance specifications. Gravity-induced deformations can be calculated and corrected with high precision. While the time-variable nature of temperature- and wind-induced deformations can only partially be explored in numerical simulations, their control requires the input from metrology. Corrections can be made through the telescope control system but also, to some extent, through deformable mirror surfaces. The progress in metrology and the correction of certain telescope errors are described. 相似文献
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借助脉冲的等效时间复参数讨论了Sech型光脉冲通过光纤一光栅对系统后的传输和变换特性,给出了脉冲压缩的最佳条件,为处理非高斯型光脉冲经过线性系统的传输提供了一种有效的方法。 相似文献
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Basavaiah Jagadeesh Anthony Audre Arlene Patil Chandrashekar Mohan 《Wireless Personal Communications》2022,122(1):489-499
Wireless Personal Communications - Various research groups are working on the automated detection of epileptic seizures using Electroencephalogram (EEG) data. EEG waveforms are composed of distinct... 相似文献
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借助脉冲的等效时间复参数讨论了Sech型光脉冲通过光纤─光栅对系统后的传输和变换特性,给出了脉冲压缩的最佳条件,为处理非高斯型光脉冲经过线性系统的传输提供了一种有效的方法。 相似文献
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本文导出了高斯光束通过非线性抛物形梯度折射率棒透镜的变换公式。结果表明,它的变换特性依赖于光功率、入射光束的束腰、物距以及透镜参数。 相似文献
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介绍了舰载雷达侦察系统常用坐标系转换方法,包括舰船地理坐标系到舰船甲板坐标系的变换及逆变换、舰船甲板坐标系到阵面坐标系的变换及逆变换,给出了具体的推导过程及坐标系相互转换的公式,结合坐标系转换的理论方法,阐述了舰载雷达侦察系统坐标系转换的应用实例. 相似文献
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根据视觉认知规律,提出描述野外场景图像的三要素:地面、垂直物、天空,给出了单视角野外场景图像方程,通过采用基于独立图元函数码的三要素图像快速分类方法,实现对野外场景图像的分割,并且只在地面上去识别水体.本文重点讨论了野外场景中水体光照模型,分析了野外场景的相关物理特性,定义了水质参数、环境染色参数、图元、独立图元函数码、母图元等新概念,给出了野外场景分析与水体识别系统,提出基于位置、纹理、地质系数和环境染色等多特征参数的数据融合水体识别方法.实验表明该方法对于宽阔的道路场景分析和道路上的水体识别可以得到很好的效果. 相似文献
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有源相控阵雷达阵面监测方法及其实验研究 总被引:3,自引:3,他引:0
分析了有源相控阵雷达阵面内、外监测方法的优缺点,通过一个有源相控阵试验系统验证了这两种监测方法,并给出了实验数据和图表 相似文献
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The rapid development of mobile Internet triggered massive data exchange among multiple sources, which then results in challenges in the efficiency of multi-user data transmission. Spatial coupling multiple access, where different users share the same resource blocks by superimposing data streams with different time offsets, has been proposed to obtain higher spectral efficiency. The optimization of the system can be carried out through for example constellation rotation or power allocation, which mitigates the interferences and distinguishes users/data streams better. The optimization aims for the maximization of the average mutual information between the transmitted data symbols and the received signal. To solve the optimization problem, we employ machine learning based methods to locate the possibly global optimal solution. Simulation results show that the optimization clearly contributes to the performance improvement of the system. 相似文献
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为了加强多媒体计算机用有源扬声器系统的质量控制,规范测量方法,兹参照有关标准,提出了小体积、低功率有源扬声器系统的测量方法,并做了实际验证。 相似文献
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《Microwave Theory and Techniques》1982,30(12):2139-2145
Approximate methods are used to obtain the modal properties of stripe-contact semiconductor injection lasers using a planar three-layer waveguide model. The central active layer has a dielectric constant that varies smoothly along the direction parallel to the heterojunction boundaries. The complex dielectric constant under the stripe contact is dependent on the gain and approaches a constant value at large lateral distances. The two methods are compared in terms of their modal propagation constants. An application of the effective index method facilitates a physical understanding of dielectric waveguide modes as well as providing an efficient calculation procedure. 相似文献