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DCT-and-Image-Compression
DCT and Image Compression
In the JPEG image compression algorithm, the input image is divided into
8-by-8 or 16-by-16 blocks, and the two-dimensional DCT is computed for each
block. The DCT coefficients are then quantized, coded, and transmitted. The
JPEG receiver (or JPEG file reader) decodes the quantized DCT coefficients,
computes the inverse two-dimensional DCT of each block, and then puts the
blocks back together into a single image. For typical images, many of the
DCT coefficients have values close to zero these coefficients can be discarded
without seriously affecting the quality of the reconstructed image.
The example code below computes the two-dimensional DCT of 8-by-8 blocks
in the input image, discards (sets to zero) all but 10 of the 64 DCT coefficients
in each block, and then reconstructs the image using the two-dimensional
inverse DCT of each block. The transform matrix computation method is used.
- 2014-01-28 16:55:07下载
- 积分：1
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dianjifankuikongzhiZH
转速、磁链闭环控制的矢量控制交流调速。控制电路是由滞环脉冲发生器、电流变换与磁链观测的封装模块、比例放大器模块、函数模块、常数模块（用于额定转速和转子磁链信号的给定）、转速调节器ASR、转矩调节器ATR、磁链调节器APR、以及三二变换器模块。(Vector Control AC Speed Regulation with Closed Loop Control of Speed and Flux Link)
- 2018-12-29 16:54:36下载
- 积分：1
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stdshadetest1
Short code to create shading around a mean. Input is a matrix with rows of observations
- 2011-01-21 09:27:42下载
- 积分：1
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Tut_MatlabNNT
Introduction to The Matlab Neural Network Toolbox (NNT)
- 2009-07-16 20:52:52下载
- 积分：1
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time-varying-gravity-field
说明： 计算时变重力场变化的程序，通过此程序可以计算地球质量变化等等。(Changes in time-varying gravity field calculation program, this program can be calculated by changes in Earth' s mass and so on.)
- 2011-04-13 11:24:01下载
- 积分：1
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OFDM rece matlab
接收端采用的算法和程序流程与发送端发送的OFDM符号的帧结构有关系。具体的帧结构，以及定时估计，频偏估计，剩余误差跟踪的算法可参考算法说明文档。这里对程序的流程进行说明。
首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。
(The receiving end uses the algorithm and the program flow and the frame structure of the OFDM symbol transmitted by the sending end. Specific frame structure, and timing estimation, frequency offset estimation, residual error tracking algorithm can refer to the documentation. Here to illustrate the process of the program.
First, according to the characteristics of the short training word correlation operation, the signal reaches the detection, when the correlation value is greater than the threshold of a certain number of times, that there is a signal to reach. Then, according to the characteristics of the long training word, the correlation operation is carried out, and the initial position of the OFDM symbol FFT is estimated. The estimated position of the FFT window, first in the time domain for small frequency offset estimation, two long training word for small frequency offset compensation, the FFT operation. According to the result of FFT for integer frequency bias estimation. Af)
- 2020-11-05 00:19:52下载
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matlab
分别对正弦波，三角波，方波，一周期内取为整数的64个点（A=4095）；写锯齿波和方波的谐波构成（只写了3、4个）。(Of sine wave, triangle wave, square wave, A week off for integer in the period of 64 points (A = 4095) Write a sawtooth wave and square wave of harmonic (only wrote 3, 4).)
- 2013-08-10 21:49:09下载
- 积分：1
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raygen
source code of rayleigh fading environment
- 2010-06-10 18:04:44下载
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Mseires
用MATLAB产生M序列作为系统的输入，根据传递函数，仿真输出，并得出输入的自相关函数和输入输出的互相关函数。(M sequence generated by MATLAB as input, in accordance with transfer function, simulation output, and come to enter the auto-correlation function and the input and output of the cross-correlation function.)
- 2009-06-18 22:21:51下载
- 积分：1
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program_NMEA_YieldRate
matlab檔案，用於計算定位成功率，輸入nmea檔案，自動計算NMEA定位的成功率(Calculate the fix yield rate)
- 2014-02-21 10:17:59下载
- 积分：1
