查询词典 fast algorithm

The algorithm used to implement fast Fourier transform of real-valued with complex-valued Fourier algorithm and the algorithm used to compensate the decaying direct current with arbitrary decay time parameter are deduced in detail.

对其中的一种用复序列DFT算法分析实数序列的算法和一种用来对具有任意衰减时间参数的衰减直流分量进行补偿的算法进行了详细推导。

Based on X-filtered LMS algorithm and -filtered LMS algorithm adaptive inverse control, we use a new variable step size LMS algorithm. Adding little computation, variable step size LMS algorithm can result in fast convergence speed and low residual error simultaneously. The adaptive feedback control can counteract the beginning error of the system. The adaptive disturbance canceler can best erase noises and disturbances.

在原来的X-滤波LMS算法自适应逆控制和-滤波LMS算法自适应逆控制方法的基础上，引入了新的变步长LMS算法，在计算量增加不多的前提下，能同时获得较快的收敛速度和较小的稳态误差；引入自适应的反馈补偿控制克服了被控系统的直流零频漂移，使控制系统在初开始工作阶段快速收敛；还引入自适应扰动消除器，它能最大限度的消除扰动。

to reduce the impact of carrier frequency offset in ofdm system,this thesis designs a new carrier frequency offset estimation scheme for ofdm system.the carrier frequency offset estimation includes acquisition and tracking.we adopt variable step size adaptive algorithm.the acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth.through this method we can not only avoid the feedback by using forward error correction,but also reduce the times of complex multiplication in order to reduce the power consumption of the system.this algorithm not only has low complexity and fast convergence nut also can improve the demodulation performance of ofdm system.computer simulation illustrates the superior performance of the proposed algorithm with regard to estimation accuracy in both awgn channel and multi—path channel.

摘 要：为了减小正交频分复用系统受频率偏差的影响，在ofdm系统中设计了一种新的载波频偏估计算法。频偏估计包括跟踪和捕获两个阶段，文中采用变步长自适应算法来进行跟踪，这个跟踪算法的捕捉范围是整个信号带宽的一半。通过此方法，不但可以利用前向纠错的方式来避免反馈，而且可以缩减复数乘法的次数以降低计算复杂度和系统功耗。该方法运算复杂度低，并具有较好的收敛性，能改善odfm的解调性能。从计算机的仿真效果可以看出无论是在awgn信道上还是在多径信道上都表现出了卓越的性能。

Under microcomputer circumstance a human-interactive graphic system is developed. An algorithm for hidden line removal based on improved appel algorithm and an algorithm for fast shaded graph are presented.

在表达比较复杂的零件内部结构时，设计和实现了一个任意三维形体阶梯剖切算法，可以对任意零件实体进行任意方向、任意位置连续的多刀剖切，并且剖切操作方便。

The convergence speed of forward algorithm is as fast as ten times of backward algorithm.Additionally,the decrypted image quality and noiseproof ability for the forward algorithm are also higher than the backward algorithms obviously.

不仅如此，整个算法的收敛速度比后向算法快一个数量级，而且无论迭代结果的解密图象质量还是抑制噪声能力也都明显优于后向算法。

The traditional algorithm of Volume Rendering is Ray-Casting, not a proper algorithm for the large 3-D seismic data, referring some improved method and considering the characteristic of seismic data, a new fast Ray-Casting algorithm of oriented image space and negative-view transform was brought forward. As a result, this algorithm excels the traditional obviously by speed with image quality in experiment.

体绘制的传统算法是光线投射法，由于地震数据量大而绘制速度太慢，本文在借鉴一些改进算法的基础上，结合地震数据的特点，提出了一种基于图像空间的逆视变换的加速光线投射算法，实验结果表明该算法在保证相同图像效果的同时，具有明显的速度优势。

Thirdly, the principal curve and polygonal line algorithm are introduced, and an implementation of polygonal line algorithm based on Quasi-Newton numerical optimization is illustrated. The simulation results show that when this algorithm isused in the detection of curvilinear defects on wafer map, it can converge fast, compute accurately and meet the demand of application of defects pattern analysis, and with the number of line segment increasing, the polygonal line will approximate to the Kegl principal curve.

研究了主曲线、多边形线算法，提出用多边形算法识别弧状缺陷想法，讨论了用拟牛顿法实现该算法的解决方案，针对硅片缺点模式分析中常出现的弧状缺陷，采用该算法进行检测分析，实验结果表明这种算法快速准确，当线段个数或最小距离平方期望值达到一定门限值后，多边形线就已经能够描述弧状缺点集的形状，随着线段个数增加，最小距离平方期望值还在不断下降，最终会收敛到Kegl主曲线。

First, the traffic flow time series chaotic feature is extracted by chaos theory. pretreatment for traffic flow time series, and the wavelet neural networks model was build by this. Second, the chaotic mechanism and the chaotic probability is described. Based on chaotic learning algorithm, and the wavelet neural networks fast learning algorithm of traffic flow time series is designed based on chaotic algorithm. Last, a single-step and multi-step prediction of traffic flow chaotic time series is researched by BP neural networks, wavelet neural networks and wavelet neural networks based on chaotic algorithm. The results showed that the wavelet neural networks predictive performance is better than the BP networks and the wavelet neural networks by the simulation results and root-mean-square value.

首先，通过混沌理论提取了交通流量时间序列的混沌特征，并在此基础上建立了小波神经网络交通流量时间序列模型；接着，阐述了混沌学习算法的混沌机理、混沌产生的概率，设计了基于混沌算法的小波神经网络交通流量混沌时间序列快速学习算法；最后利用交通流量混沌时间序列对BP网络、非混沌算法的小波神经网络以及基于混沌算法的小波神经网络进行了单步预测和多步预测，并对预测结果的仿真图和真实值与预测值的方均根进行了比较，结果表明基于混沌学习算法的小波神经网络的预测性能明显优于应用BP网络和非混沌算法的小波神经网络。

the fast transposition algorithm to sparse matrix expressed by triple list is introduced.this algorithm needs to determine the position in the transposed matrix position of the first element which is not equal to zero in the original matrix each row,it uses two arrays as auxiliary space.in order to reduce the auxiliary space which the algorithm needed,an improvement is made through introducing two simple variables.the improved algorithm saves a half auxiliary space compared to the original algorithm at the same time complexity.

摘 要：介绍基于三元组表表示的稀疏矩阵的快速转置算法，此算法在转置前需要先确定原矩阵中各列第一个非零元在转置矩阵中的位置，在此使用2个数组作为辅助空间，为了减少算法所需的辅助空间，通过引入2个简单变量提出一种改进算法。该改进算法在时间复杂度保持不变的情况下，空间复杂度比原算法节省一半。

In this article, we firstly review the history that Wavelet developed, after that, we discuss filter algorithm including FFT algorithm, Fast-running algorithm and Distributed algorithm.

在本文中，首先回顾了小波发展的历史，然后讨论了滤波算法，较详细了分析了快速傅立叶算法、快行滤波算法和分布式算法，在此基础上，简要的讨论了小波变换的单层分解。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。