查询词典 mean square

As a result, the mass matrix, the stiffness matrix, the damping matrix and the excitation coefficient matrices of the dynamics differential equations are random parameter matrices. According to the minimum deviation rule of the mean squares between the random parameter system and the deterministic parameter system, the random mean square deviation vector function between the two systems has been set up and the deterministic parameter system has been solved.

应用Newton-Euler矢量法对挂接车辆系统建立了质量阵、刚度阵、阻尼阵和激励系数阵皆为随机参数阵的八自由度随机参数系统动力学微分方程，并按照随机参数系统与确定性参数系统之间的均方值偏差最小的原则，建立了两系统之间的随机均方偏差矢量函数，由此解出了相应的确定性参数系统

The root mean square error for regressed rainfall is around 65﹪ of the standard deviation and about 15﹪ of the mean rainfall.

回归的平方根误差是其标准差的60％和平均雨量的15％。

It was found that both the root mean square error and the mean error were minimal when using the neural network and fuzzy controller.

在临床试验部分，本研究针对四位受测者进行不同控制器的控制品质比较，结果发现以类神经网路加上模糊控制器的控制方法，其均方根误差及平均差皆为最小。

Monte Carlo and self-adaptive multi-objective genetic algorithm were applied to solve the multi-objective robust optimization of suspension parameters, taking the statistic mean and standard deviation of root-mean-square value of the vertical acceleration of vehicle body and the dynamic load of front and rear tires as objective functions.

以某载货汽车的四自由度悬架模型为研究对象，同时考虑制造精度的影响，以车身垂直加速度、前后轮胎动载荷的均方根值的统计均值和方差为目标函数，采用蒙特卡罗抽样法和自适应多目标遗传算法对悬架参数进行稳健优化。

It is recommended to take the ratio of the root-mean-square power and the mean power, instead of the ratio of the thermocurre...

最后讨论了合理负载系数问题，认为"大马拉小车"并不是电动机效率低的主要原因。

The experimental results show that the proposed method can obtain good performance in terms of both objective evaluation criteria such as root-mean-square error,signal-to-noise ratio,mean error and visual subjective evaluation criteria.

实验结果表明，无论是依据均方根误差、信噪比、灰度平均误差等客观评价标准，还是视觉的主观评价，所提出的融合方法都能取得较好的性能。

The experimental results indicate that prime root-mean-square deviation measured by this method is almost linear with the arithmetical mean deviation of the surface-samples.

实验结果表明，应用本测量方法得到的轮廓均方根偏差最佳估计值σp与表面样品给定的轮廓算术平均偏差Ra成很好的线性关系。

In this topic, in order to derive the approximate cross-correlation function in frequency domain, we propose the simple estimation of the root-mean-square delay spread and the mean delay of the channel.

在这议题中，为得到在频域的近似通道交互相关函数，我们推得通道的"延滞方均值"与"延滞均值"简易估计演算法。

Density Functional Theory method was used to optimize the geometries of 209 PCDE molecules, 209 PBDE molecules and 75 PCDD molecules at the B3LYP/6-31G* level. Using computed structural parameters as theoretical descriptors, the forward stepwise multiple regression technique was adopted to obtain QSPR models of environmental partition properties for these POPs by using GQSARF 2.0 and SPSS12.0 for windows programs. The obtained QSPR models are as follows:(1) QSPR models for predicting subcooled liquid vapor pressure, n-octanol/water partition coefficients lgK_(ow and subcooled liquid water solubilities -lgS_(w,l of PCDEs, of which correlative coefficients (R~2) are 0.988, 0.958 and 0.959 and the root-mean-square-error of estimation are 0.134, 0.116 and 0.327 respectively.(2) QSPR models of lgPL and n-octanol/air partition coefficients lgK_(oa for PBDEs, which both contain three structural parameters. The values of R2 for the two models are both 0.997 while the values of RMSEE are 0.073 and 0.062 respectively.(3) QSPR models of lgKow and–lgS_ for PCDEs, which both have one variable (mean molecular polarizability,α). The values of R~2 for the two models are 0.978 and 0.866 and the values of RMSEE are 0.300 and 0.270 respectively.(4) The molecular structures of 24 substituted naphthaline compounds were optimized using Hartree-Fock and DFT methods at four different levels and the same means was used to obtain four three-parameter (EHOMO, q~+ andα) QSPR models of lgK_. The model at the HF/6-311G** level is the best one of which R2 is 0.9662 and RMSEE is 0.380.(5) QSPR study for environmental partition properties of PCDEs was also performed using position of Cl substitution method in which simple parameters of substitution position were taken as descriptors. The multiple linear regression was performed with GQSARF 2.0 and SSPS 12.0 for windows programs to obtain QSPR models of lgP_L, lgK_ and–lgS_ for PCDEs of which R~2 are 0.991, 0.983 and 0.965 and RMSEE are 0.311, 0.100 and 0.300 respectively.

采用密度泛函理论方法在B3LYP/6-31G*水平上对PCDEs、PBDEs和PCDDs的分子结构进行了全优化计算，以计算得到的量子化学参数作为理论描述符，采用GQSARF 2.0和SPSS 12.0 for windows统计程序进行正向逐步回归分析，建立了这些POPs的环境分配性质的QSPR模型：(1) PCDEs的过冷液体蒸汽压、正辛醇/水分配系数lgK_(ow和水溶解度-lgS_(w，l的QSPR模型，这3个QSPR模型的相关系数(R2)分别为0.988、0.958和0.959，估计的均方根误差分别为0.134、0.116和0.327；(2) PBDEs的lgPL和正辛醇/空气分配系数lgK_(oa的QSPR模型，这两个模型都包含三个分子结构参数，其R~2都为0.997，RSMEE分别为0.073和0.062；(3) PCDDs类化合物的lgK_和-lgS_w的QSPR模型，两个模型都只含一个变量，其R~2分别为0.978和0.866，RSMEE分别为0.300和0.270；(4)采用Hartree-Fock和DFT方法，在4种不同水平上优化计算了24个取代萘系列化合物的分子结构，采用上述同样的方法分别建立了四种水平上的三变量lgK_模型，通过比较得到，在HF/6-311G**水平计算得到的模型最好，R为0.966，RSMEE为0.380；(5)同时，采用氯原子取代位置方法对PCDEs的环境分配性质进行QSPR研究，建立了PCDEs的lgPL、lgK_和-lgS_的QSPR模型，其R~2分别为0.991、0.983和0.965，RSMEE分别为0.110、0.100和0.300。

Periodic fluid pulsation in aeroplane hydraulic piping could induce fluid-construction vibration and lead to fatigue damage. It is impossible to find the error sensor's optimization location because of the pressure standing wave, and the pulsation attenuation effect is not perfect when adopting pulsation attenuation at single point. For this reason, a distributed active control method of fluid pulsation was presented. To avoid stationary point in all aviation states, several fluid pulsation actuators and error pressure sensors were placed along the piping. The second fluid pulsation produced by actuators can counteract the primary pulsation brought by aviation piston pump and make the mean pulsation of whole piping minimum when adopting adaptive feed- forward control and the filtered-X least mean square algorithm.

针对飞机液压能源管路系统中的周期性流体脉动诱发流固耦合振动，导致管路疲劳损伤的问题，针对管路中存在压力驻波特性，在采用单点消振时寻找误差传感器最佳布局位置困难而引起脉动抑制效果不理想的缺点，提出了一种分布式流体脉动主动控制方法，即沿管路不同位置布置多个主动消振阀和误差压力传感器，在任意飞行阶段，避开压力驻波点，以误差压力传感器的脉动测量值为控制目标，采用一种针对周期脉动主动控制的自适应前馈控制法和多通道自适应滤波－X LMS算法，调整控制器参数，使主动消振器产生的次级脉动与管路中的初始脉动相互抵消，达到整个管路中的平均流体脉动最小的效果。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。