域

Based on this, aim at the disadvantage on Wigner Distribution and Fractional Fourier Transform that can't restrain noise interference effectively when be used to detect Linear Frequency Modulated signals interfered by heavy noises, we proposed a improved WD. Simulation results show that this method can restrain noise interference effectively and improve the ability of LFM signals detection. On the other hand, in multi-component cases, WD suffers from the cross-terms, which may impair some of the auto-terms. In order to separate original multi-component signals into components and reconstruct them separately, we can use the method of optimal filtering in fractional Fourier domain. But this method also has a problem that if signals have aliasing in the fractional Fourier optimal domain as well, the reconstructed signals will be distorted. In this thesis, a novel method of quasi Fourier transform is proposed in order to solve the problem of multi-component signal reconstruction, and have good results.

在此基础上，针对Wigner分布和分数维傅里叶变换在处理高噪声背景下线性调频信号检测的问题时存在不能有效抑制噪声干扰的缺点，提出了改进Wigner分布的办法，该方法能够抑制噪声，提高信号的检测能力；针对Wigner分布在处理多分量非线性调频信号时存在干扰项的缺点，以及分数域最优滤波方法在处理多分量非线性调频信号分离重构问题时存在的局限性，该局限性表现为在对最优分数域上也有信号分量重叠的情况进行处理时重构信号发生畸变，提出了新颖的类傅里叶变换的方法，该方法对在最优分数域上也有信号分量重叠的情况也能处理，得到的重构信号失真很小。

A tooth-shaped waveform forming unit (105) shapes the waveform of the frequency range signals outputted from the repetition unit (104), into a tooth-shaped waveform, and an IFFT unit (106) converts the frequency range signal outputted from the tooth-shaped waveform forming unit (105), into a signal of a time range.

在梳齿状波形生成单元(105)，将由重复单元(104)输出的多个频域信号波形生成为梳齿状波形，而在IFFT单元(106)，将由梳齿状波形生成单元(105)输出的频域信号，变换为时域的信号。

Too much emphasis has been laid on thephase coherence detection using the arithmetics of auto-correlation in time domain,spectrum analysis in frequency domain and feature extraction of intra-pulse modulatedsignals employing the methods of quadrature in time domain、Short Time FourierTransform、Wigner-Ville Distribution and Radon-Wigner Transform.

本文详细介绍了脉冲多普勒雷达的原理及其信号特征、相参性原理、脉内调制信号、时频分析理论和模式识别理论等，重点讨论了利用时域自相关法和频域谱线分析法进行相位相参性的检测；详细分析了脉内调制特征提取的几种方法，主要包括时域正交、短时傅立叶变换、维格纳分布和 Radon-Wigner 变换。

After comparing the time domain approach of estimating azimuth and slowness in the f-k method with the frequency domain, it is shown that the time domain approach actually is not less accurate or efficient than the improved frequency domain approach, and in the case of signal-to-noise ratio is very low, the results obtained from the time domain approach are more reliable.

进一步对在时域中直接估算信号方位角和慢度的一种算法进行了分析，比较发现时域方法的计算速度和精度都不低于频域方法，且在某些低信噪比的情况下，前者可以给出更可靠的结果。

Because seismic boreholes were deployed in the middle of coal seam, the energy of dynamite would be distributed symmetrically on the face of coal seam.

其中高频区大约以2000 Hz为中心，低频域的中心频率约为490 Hz，并且高频域和低频域的能量差异不显著。

The fan delta, sand beach, sand bars and turbidite fan in the TST of SⅡ and SⅢ sequences are the most favorable exploration targets because of favorable source - reservoir - seal assemblages. Since the high - stand system tract in SⅡ sequence has good source - reservoir assemblage and is covered by the regional seal of SⅢ sequence, the hydrocarbon accumulation in this area is controlled by the local seal rock. The HST of SⅡ sequence becomes the second favorable exploration target zone. Because the scales of the sand bodies of alluvial fan and braided river in low - stand system tract of SⅡ and SⅢ sequences are limited, the formation of a large hydrocarbon accumulation is difficult.

良好的生储盖配置使SⅡ层序、SⅢ层序水进体系域的扇三角洲、滩坝及浊积扇砂体成为本区最佳勘探目标层。SⅡ层序高位体系域生储条件配置好，又有SⅢ层序区域盖层的整体封盖，油气聚集受局部盖层直接控制，可成为较有利的勘探目的层。SⅡ层序、SⅢ层序低位体系域的冲积扇、辫状河砂体体积规模较小，难以形成大油气藏。

This method can not only detect the presence of hidden message but also identify the hiding domains.

该方法不仅仅能较准确地识别出是否隐藏了信息，还能识别出信息隐藏的隐藏域，即DWT域、DCT域，或者空域。

In this study, the atmospheric gravity admittances in both frequency and time domains are determined respectively.

本文在频率和时间域内分别测定了大气重力导纳值，结果说明在时域内的导纳值为－0.307μGal／hPa（1Gal＝1cm／s2），而在频域内的大气重力导纳值变化范围在0.3～0.5μGal／hPa之间，这一结果与理论模拟计算相符。

As for synaesthesia, it is a cross-domain mapping from a source sense to a target source.

对于通感而言，正是一种从一种源域到目标域的跨域映射。

The provided domain VPN information is in one embodiment spread to other domains under constrictions put by SLAs between domain operators.

在一个实施例中借助于由域运营商之间的SLA所施加的限制将所提供的域VPN信息扩展到其它域。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。