有效时间

The results indicate that the dynamic shear rheological test helps to obtain the continuous relaxation time spectrum suitable for the research on the pavement performance of asphalt mixture.

结果表明，动态剪切流变试验能够有效获得连续松弛时间谱，连续松弛时间谱能够为沥青混合料的工程性能研究提供有利手段。

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

If this field is not present, the effective date/time should default to the current date/time.

如果此字段不出现，有效日期/时间应默认当前的日期/时间。

Compared with the same wave problems with conventional Dirichlet boundary conditions, the absorbing boundary conditions can reduce the numerical reflection on boundaries and avoid solution distortion. In addition, the central differences method is economic in memory requirement and computing time compared with implicit integral method.

结果表明：该解法在空间上具有谱精度，在时间上达到二阶精度；与第一类边界条件相比，吸收边界有效地削弱了边界上的数值反射，避免了解的失真；使用中心差分的时间积分方法同隐式积分方法相比，适合波的传播特性，避免了矩阵求逆运算，并且占用的计算机内存小。

Time Inter-plug circuit is the key module of random sample DSO. It can improve the equivalent sample rate and horizontal time discrimination of DSO efficiently.

时间内插电路是随机取样数字存储示波器的关键电路，能有效提高数字存储示波器的等效采样速率和水平扫描时间分辨率。

Then both static and dynamic neural networks are applied to predict the multivariate nonlinear time series. At last, the evaluation functions of root...

通过对实际的多维时间序列仿真，结果证明本文提出的神经网络结合主成分分析的方法预测多变量非线性时间序列是快速有效的。

It provides a way to find optimal lower dimensional approximations of the given data, and It enormously reduce the storage of the data which is needed when the physical processes is recurred. The physical process can be described in series expansion function that only is related to the time and space. It is optimal approximation of the given data in a certain least squares optimal sense. The most obvious advantage of the method is that it reduces the computation cost and computation time markedly.

它提供了一种描绘物理过程的有效方法，该物理过程可以写成一个只与时间相关的函数和一个只与空间相关的函数的展开式序列，且它们在均方意义上是最优的，在展开式中只需要少量的项数就可较准确地描述该物理过程，因此降低计算维数、减少计算量和节省计算时间是这个方法最明显的优点。

Serving to save time through an efficient method or a shorter route; expeditious.

可节省时间的可通过一个有效的方式或一个更短的路径节省时间的；迅速的

In the aspect of shrimp migration test, the finding reports that shrimp would use the porosity filtering to crawl towards upstream when the flow rate is at 0.001cms, and do so on the bottom of the fishway when the flow is even less.

试验结果显示，在水理试验方面，改良后鱼骨型鱼道水位皆比原鱼骨型鱼道高，流量则比原鱼骨型鱼道低，显示多孔隙滤材能有效改善流况；排砂试验方面，泥砂约於时间第30分钟即达到输砂平衡，排砂率在97％以上，残留於鱼道之泥砂为3％以下，证明增设多孔隙滤材并不影响其排砂率；鱼类上溯试验方面，粗首鱲於试验时间内，上溯率达73％以上，皆比原鱼骨型鱼道为高，显示改良后鱼骨型鱼道更适於鱼类上溯；而溪虾上溯试验方面，发现溪虾於流量0.001时，藉由多孔隙滤材向鱼道上游攀爬，再由量更小的情况下，溪虾便由鱼道渠底向上游攀爬。

Cultures very in the notion of time and of getting down to business,' or using efficiently.

在安排时间的随意性或是有效利用时间的概念上，各种文化观点不同。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。