查询词典 spectral

The packet error rate and channel estimation are used to compute the adaptive threshold in order to maximize spectral efficiency under given delay and error performance constraints.

该技术结合了传统物理层自适应调制和链路层自动请求重发，利用链路层的误包率和信道估计参数计算自适应调制门限，在系统给定时延和误包率约束的基础上最大程度地提高了频谱利用率。

A second method for enhancing the identification process of the fringe is a variant of the two wavelength method. We require two wavelength that have a wide spectral separation in the order of 100nm.

第二种方法来提高条纹鉴别力是双波长方法的变形，使用双波长来获得宽光谱间隔在100nm的量级。

The following are the major work in this thesis which has been studied and still needs to be studied further in the future: 1 An improved adjoint variational method is developed, thus it can be applied to the LAGFD-WAM Wave Numerical Model for data assimilation; 2 A linear evolution equation of spectral perturbation is derived in order to analyze its increasing or decreasing mechanism.

本论文主要完成了以下几个方面的研究： 1）建立了推广形式的共轭变分同化方法，使之能够应用于LAGFD-WAM海浪数值模式； 2）导出了扰动谱线性演化方程，分析了扰动谱增长、衰减机制，考察了涌浪情况下扰动谱的持续时效问题及风浪情况下扰动的演变过程； 3）利用波谱共轭方程初步分析了同化模型中距离泛函的敏感性及敏感区域空间分布； 4）将推广的共轭变分方法应用于海浪谱能量平衡方程，建立了连续形式的海浪同化模型，特别是严格导出了风输入、破碎、底摩擦、波波非线性相互作用和波流相互作用各源函数的共轭源函数表示式； 5）分别进行了波谱层次上和有效波高层次上的同化试验，并对数值结果进行了分析。

Audio waveform statistical characteristics: base on high order spectral analysis methods, detect forgeries using bispectral analysis. Use matlab for experiments and perform analysis on the result.

音频波形统计特征方面：从高阶频谱分析理论出发，研究了高阶频谱分析的检测方法，并利用三阶频谱篡改检测使用matlab工具进行实验并分析实验结果，最后对整个方法进行分析以及思考。

Secondly, according to the spectral correlation theory of second order cyclostationary processes, maximumlikelihood filters are used to estimate the cyclic spectra. By estimating the crossspectra of the two frequency shifted versions of cyclostationary signal, the cyclic spectra can be obtained. The analysis effective bandwidth of maximumlikelihood filters is studied in details. In case of cross-spectra estimation, the analysis effective bandwidth of maximum-likelihood filters is not correct. A new method to calculate the analysis effective bandwidth is presented.

第二，根据二阶周期平稳随机信号的谱相关理论，提出了循环谱密度估计的最大似然滤波器法，即采用最大似然滤波器估计出周期平稳信号的两个频移分量之间的互谱密度，从而得到了循环谱密度的估计；对最大似然滤波器的有效分析带宽做了详细的分析，指出了在互谱密度估计时以往的有效分析带宽不正确，并提出了互谱密度估计时的有效分析带宽的新的计算方法。

In order to use spectral analysis theory to calculate s econd-order wave forces which naval architectures suffered in the random sea wa ves, the second-order wave forces which naval architectures suffered in any one regular wave or any two regular waves should be calculated firstly.

为了采用谱分析方法预报海洋结构物和船舶在随机海浪中所受的二阶波浪力，必须先求得海洋结构物和船舶在任意单色波和双色波中受到的二阶波浪力。

In some high_precision color reproduction applications, there is a need to obtain spectral reflectance of each point on the object s surface.

一些对颜色重现要求较高的应用领域需要获取目标表面上各点的光谱反射率。

Some classical applications and research progress are introduced, such as, selective amplification, frequency multiplication, up-conversion and signal generation in the terms of the gain spectrum as well as the carrier suppression and phase shift from the loss spectral point of view.

从受激布里渊散射增益谱的角度对微波光子信号的选择放大、倍频、上变频和信号产生以及从损耗谱的角度对信号载波抑制和信号相移等典型应用和研究进展进行了介绍。

The conventional methods used in mapping the depth of temperature approaching to the Curie point are the spectral analysis and equivalent layer model based on geomagnetic data.

传统的居里面深度探测方法包括谱分析方法、等层模型方法和温度－深度剖面法。

From the stationary, Gaussian and spectral constructural point of view, we considered that the IR noise can be described with fratcal Gaussian noise , and proposed a scheme for simulating IR noise used in simulation studies.

该方案可对帧间相关性进行模拟。2）提出了一种用于从三维数据中提取目标轨迹的有向高阶相关方法，并对该方法的检测概率、噪声抑制能力及计算量等性能进行了较详细的分析。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。