搜索结果: 16-24 共查到“知识库 工学 wavelet transform”相关记录24条 . 查询时间(0.062 秒)
Impact of Polarization-mode Dispersion on Wavelet Transform Based Optical OFDM Systems
Fiber optics communications Modulation
font style='font-size:12px;'>
2015/6/4
The impact of PMD on wavelet transform based optical OFDM (WTO-OFDM) systems is investigated. Simulations show that WTO-OFDM is very sensitive to PMD. A 1-dB penalty at 5-ps DGD is incurred for 112-Gb...
Open Quotient Measurements Based on Multiscale Product of Speech Signal Wavelet Transform
Open Quotient Measurements Multiscale Product Speech Signal Wavelet Transform
font style='font-size:12px;'>
2009/9/4
This paper describes a multiscale product method (MPM) for open quotient measure in voiced speech. The method is based on determining the glottal closing and opening instants. The proposed approach co...
基于IRM和小波变换的圆度误差在线检测技术（Roundness On-machine Measurement Method Based on IRM and Wavelet Transform）
圆度 在线检测 改进反向法
font style='font-size:12px;'>
2009/8/11
针对提高圆度误差在线检测精度的两个关键问题——主轴回转误差分离和环境噪声消除，提出了一种基于IRM（改进反向法）和小波变换的圆度误差在线检测方法。运用IRM实现在线检测中主轴回转误差与圆度误差的分离；采用基于小波变换的消噪滤波方法，消除车间噪声和高、中频信息的干扰。实验结果表明，在线检测精度基本达到了三坐标机的离线检测精度，平均相对误差4%，重复测量精度基本一致。
Transformer Protection Using the Wavelet Transform
Differential Protection Power Transformer Discrete Wavelet Transform (DWT)
font style='font-size:12px;'>
2009/7/28
This paper introduces a novel approach for power transformer protection algorithm. Power system signals such as current and voltage have traditionally been analysed by the Fast Fourier Transform. This...
基于离散小波变换的二甲醚HCCI爆震试验（Experimental Analysis of Knock in a DME HCCI Engine Using Discrete Wavelet Transform）
二甲醚 均质压燃 爆震
font style='font-size:12px;'>
2009/5/22
在一台由柴油机改造为二甲醚进气道喷射的发动机上，用离散小波变换分析正常燃烧工况、爆震工况的缸内压力，计算其在各尺度细节部分的能量特征值，研究二甲醚HCCI燃烧的爆震特性。结果表明，正常燃烧工况、爆震工况缸内压力的能量特征值分布具有明显的规律。正常燃烧工况时，细节部分D3的能量特征值最大；爆震工况时，细节部分D1的能量特征值最大。转速升高或进气道喷射燃料添加LPG对正常燃烧工况、爆震工况缸内压力能量...
基于小波变换和BP神经网络的蛋壳破损检测（Crack Detection in Eggs with Multi-level Wavelet Transform and BP Neural Network）
鸡蛋 破损 检测
font style='font-size:12px;'>
2009/5/22
提出了一种基于多层小波变换和纹理分析的蛋壳破损检测方法。该方法对获取的鸡蛋透射图像G分量在不同水平上进行小波分解，计算和分析各水平高频细节子图像的纹理特征参数，实验确定最有效的8个特征参数作为BP网络输入，建立结构为8—20—2的BP神经网络蛋壳破损分类模型。实验表明，该方法对无破损蛋、线状破损蛋、网状破损蛋和点状破损蛋的判别正确率分别为95%、90%、95%、80%，平均识别率为90%。
a new relative radiometric consistency processing method for change detection based on wavelet transform and low-pass filter
wavelet transform radiometric normalization low-pass filter change detection
font style='font-size:12px;'>
2016/4/11
Considering the actual research purpose, this paper has shown the limitations of the existing radiometric normalization approaches and their disadvantages in change detection of artificial objects by ...
基于小波变换的大米直链淀粉波长选择方法（Region Selecting Methods of Near Infrared Wavelength Based on Wavelet Transform）
直链淀粉 近红外光谱 小波变换 波长选择
font style='font-size:12px;'>
2010/2/26
提出了一种基于小波变换的近红外光谱波长选择方法，小波分解低频系数是原光谱的离散近似，将最佳小波分解低频系数与原光谱数据进行关联，求出小波分解低频系数与原光谱数据的列相关系数R，取与原光谱数据相关系数较大的波长组合，作为最后参与建模的谱区。不仅考虑了浓度矩阵对波长选择的影响，且由于把小波分解结构中的高频系数全部滤除，避免了高频噪声的干扰，减小建模和预测运算时间，使最终建立的近红外光谱模型的预测精度提...
Accurately Weighting Subbands in Temporal Wavelet Transform
Accurately Weighting Subbands Temporal Wavelet Transform
font style='font-size:12px;'>
2010/12/16
Wavelet-based scalable video coding is a promising technique for streaming video applications,especially the Motion Compensated Temporal Filtering (MCTF). It usually decomposes the input video frames...