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03607_28
DFT进行频谱分析时的三种现象
1、混叠：对连续信号采样，要求连续信号是带限的，采样频率要足够高。Fs应满足Nyquist采样定理才不产生混叠。
采样前加低通滤波器防混叠
2、频谱泄漏：DFT对时域信号进行了截断（相当于采样信号乘了一个窗函数），时域的乘积相当于频域卷积，改变了原信号频谱。
改用其他窗函数（非矩形）改善泄漏。
3、栅栏现象：DFT 只给出了频谱在采样点上的取值，采样点间的频谱内容丢失。(DFT spectrum analysis of a three phenomena, aliasing : continuous signal sampling, requiring continuous signal is band-limited, the sampling frequency should be high enough. Fs meet the Nyquist Sampling Theorem would not have aliasing. Sampling former low-pass filter plus anti-aliasing 2, spectrum leakage : DFT right time domain signal a disconnect (equivalent to a sampling signal by a window function). time domain is equivalent to the product of frequency-domain convolution, changes in the spectrum of the original signal. Window functions to switch to other (non-rectangular) to improve leakage. 3, fenced phenomenon : DFT spectrum is given only at the sampling point value, sampling points of the spectrum as lost.)
- 2007-05-08 16:22:17下载
- 积分：1
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clark
clark transformer in matlab
- 2013-07-18 18:23:30下载
- 积分：1
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genetic_code
optimal placement dg in electrical network
- 2020-11-26 23:39:31下载
- 积分：1
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Fresnel_diffraction
菲涅尔衍射。仿真圆形光圈的菲涅耳衍射，显示菲涅耳衍射图样的模值。(Fresnel diffraction simulation of circular aperture Fresnel diffraction, display mode value of the Fresnel diffraction pattern.)
- 2016-03-24 23:03:06下载
- 积分：1
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aca
matlab中实现蚁群优化算法在30个城市中寻找一条最优路径。有说明文档。(Ant colony Optimization int matlab and provide a txt document which contains 30 city coordinate)
- 2011-01-10 14:10:42下载
- 积分：1
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upload
content of "upload" file is about digital signal processing
- 2011-01-22 20:10:55下载
- 积分：1
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detect_face
face detection in algorithm in rgb
- 2011-12-16 05:35:19下载
- 积分：1
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pim4
这是一种求解微分方程的高精度数值方法，对解决很多非线性问题有很大优势，由钟万勰院士首创(This is a high-precision numerical solution of differential equation methods, to solve many nonlinear problems has great advantages, from the first academician Zhong Wanxie)
- 2007-08-23 12:57:23下载
- 积分：1
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sfuntmpl_basic
依据simulimk中提供的程序设计的跟踪微分算法(Simulimk provided in accordance with the procedures designed to track the differential algorithm)
- 2009-12-05 18:27:10下载
- 积分：1
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youchengbianma
这是我用matlab写的一个简单的实现游程编码和解码的程序，可以读入一个图片，进行游程编码，编码后再解码输出显示。( )
- 2012-05-05 23:08:11下载
- 积分：1
