共查询到19条相似文献,搜索用时 78 毫秒
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文中首先探讨了广义相关免疫阶和非线性之间的关系;其次论述了文献中引入二次Bent函数的不合理性,并对这个概念进行了修改。 相似文献
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广义沃尔什函数的构造与生成 总被引:2,自引:2,他引:0
本文对沃尔什函数的对称复制和平移复制概念进行了推广,提出了用循环右移复制和广义平移复制方式来构造或产生广义沃尔什函数(Chrestenson函数)的方法 相似文献
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大口径移相干涉仪在检测空间频率为毫米甚至亚毫米量级的相位误差时, 存在部分空间频率的相位误差失真效应。因此, 必须对大口径移相干涉仪的频率响应函数进行标定,以保证检测数据的真实性。引用评价参数-功率谱密度, 重点研究了干涉仪频率响应函数的实验标定。在理论上建立标定干涉仪频率响应函数的数学模型, 讨论了两种标定方法—正弦相位光栅法和台阶法, 分析其各自的优缺点, 综合比较后确定台阶法作为实验方案。深入研究台阶样品可以作为标定用标准台阶的条件, 即台阶阶跃的陡峭程度与台阶信噪比的选择, 探讨了台阶法标定干涉仪频率响应函数的可行性; 设计、制作了高精度的台阶相位板, 结合实验对干涉仪的频率响应函数进行标定测量, 给出有关曲线; 最后分析了几种误差源对干涉仪频率响应函数标定结果的影响及其消除方法。 相似文献
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介绍了系统频率响应的概念,详细分析了扫频法测量系统频响的原理,最后给出了音频测试仪测量调音台单机频响曲线的实例。 相似文献
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Image fusion is a technical method to integrate the spatial details of the high‐resolution panchromatic (HRP) image and the spectral information of low‐resolution multispectral (LRM) images to produce high‐resolution multispectral images. The most important point in image fusion is enhancing the spatial details of the HRP image and simultaneously maintaining the spectral information of the LRM images. This implies that the physical characteristics of a satellite sensor should be considered in the fusion process. Also, to fuse massive satellite images, the fusion method should have low computation costs. In this paper, we propose a fast and efficient satellite image fusion method. The proposed method uses the spectral response functions of a satellite sensor; thus, it rationally reflects the physical characteristics of the satellite sensor to the fused image. As a result, the proposed method provides high‐quality fused images in terms of spectral and spatial evaluations. The experimental results of IKONOS images indicate that the proposed method outperforms the intensity‐hue‐saturation and wavelet‐based methods. 相似文献
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脑功能光学成像的迭代广义指示函数分析法 总被引:1,自引:1,他引:0
在脑光学功能成像领域,由T.Yokoo等人提出的广义指示函数法(Generalized Indicator Functions; GIF)能够在极低信噪比下有效地提取大脑行为模式图.但进一步研究发现,该算法在处理脑功能光学图像序列时存在计算量大的缺点.为解决一问题,本文将Weng等在处理FERET人脸数据库时提出的一种迭代算法与GIF算法相结合,给出了一种迭代格式的GIF算法——RGIF (Recursive GIF),RGIF算法利用迭代计算的特点能大幅削减计算量.利用仿真和实验数据对GIF和RGIF算法进行了对比分析,结果表明RGIF不仅能够大大节省计算时间,同时检测效果与GIF相当. 相似文献
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声表面波滤波器频响综合 总被引:1,自引:0,他引:1
本文介绍利用引入一个新的自变量Y(半时间带宽积)进入滤波器的频响计算公式中,可以很方便地利用预先计算好的表格、曲线设计所需要的滤波器。实践证明,理论与实际比较一致。 相似文献
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Parametric Characteristic Analysis for Generalized Frequency Response Functions of Nonlinear Systems
Xing Jian Jing Zi Qiang Lang Stephen A. Billings 《Circuits, Systems, and Signal Processing》2009,28(5):699-733
In order to explicitly reveal the relationship between system frequency response functions and model parameters which define
system nonlinearities, and consequently unveil a direct connection from model parameters to system frequency response characteristics,
a parametric characteristic analysis approach is proposed for Volterra systems described by a nonlinear differential equation
(NDE). The parametric characteristics of the generalized frequency response functions (GFRFs) for the NDE model are established,
and some important properties are discussed, which can explicitly reveal what model parameters contribute and how these parameters
affect the GFRFs. Based on the parametric characteristic analysis, it is demonstrated how the system frequency domain characteristics
are related to the system time domain model parameters and how the output frequency response function can now be determined
explicitly with a detailed polynomial structure. These new results provide a significant and novel insight into the analysis
and design of nonlinear systems in the frequency domain. Several examples are included to illustrate the results. 相似文献