查询词典 estimation of parameter

The adaptive compensation term of the optimal approximation error and a new robust term are adopted to minify the influence of modeling error and parameter estimation error.

该方案通过引入最优逼近误差的自适应补偿项和新的鲁棒项，削减建模误差和参数估计误差的影响，从而在稳定性分析中取消了要求逼近误差平方可积或逼近误差的上确界已知的条件。

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。

In this method a windowing parameter estimation algorithm is applied to obtain the initiative value of iteration for the nonuniformly sampled record.

对周期信号采样序列重建问题，提出了一种基于采用时域布莱克曼窗减少频谱泄漏的自适应迭代重建算法，该算法利用对采样序列加窗的方法，有效地降低采样长度为非整数倍信号周期所产生的频谱泄漏。

A frame image of a video frequency sequence is read into a postpositional memory zone, and staring position and size information of a tracked object is obtained in the frame, then distribution statistical information of a target signature is extracted to build a gauss mixed model as an object template, a mean vector and a covariance matrix in gauss mixed distribution are used to describe the position and the size of the object, then the next frame image of the video frequency sequence is read into the postpositional memory zone. In a new frame video frequency image, a parameter estimation method is used to obtain object gauss mized model parameters in the current frame in iterative computation and find candidate template similar to the object template, and the final model parameters obtained in iteration are used to update the tracking window for realizing self-adaption of the tracked window.

将视频序列的一帧图像读入缓存区，获得该帧中被跟踪目标的初始位置和尺寸信息，然后提取目标特征的分布统计信息建立高斯混合模型作为目标模板，用高斯混合分布的均值向量和协方差矩阵描述目标的位置和尺寸，再将视频序列下一帧图像读入缓存区，在新一帧视频图像中利用参数估计方法迭代计算当前帧中目标高斯混合模型参数找到与目标模板最相似的候选模板，利用迭代得到的最终模型参数更新跟踪窗口实现跟踪窗宽的自适应。

In consideration of the in-pulse phase modulation and Doppler frequency rate-of-change's subtleness, a fast and accurate algorithm is proposed. The influence to parameter estimation with phase modulation is dismissed by time domain correlation between neighboring pulses. Signal noise ratio is increased by frequency domain accumulation.

该文针对信号脉内相位调制和多普勒频率变化率信息非常微弱的特点，提出了一种快速高精度估计算法，通过相邻脉冲间的时域相关消除了相位调制对参数估计的影响，频域积累增强了信噪比，利用脉冲间的相参特性进行频谱相关消除了相位模糊，并放大了多普勒频率变化率信息。

In hydrological modelling one of the most common and significant challenges faced is the reduction of uncertainty in estimation and calibration of model parameters,especially how to estimate parameter values for ungauged basins and simulate the hydrological effects of basin development scenarios and water usage practices.

目前应用较为广泛的模型多为集总式模型。但是，集总式水文模型有很多缺点，如不能反映实际暴雨洪水产汇流的空间分布特性，无法全面的刻画水文系统分散输入集中输出的产汇流规律等。因此为了研究和解决变化环境中的水文水资源问题，评估和检测流域的径流过程和水资源量的动态变化规律，实现水资源的可持续利用和发展战略，必须开发研制有物理基础的分布式流域水文模型。

The sensitivity analysis results show that ticket price changes have a significant effect on flight load. Analysis of the influence of different flight departure time alteration on flight load may also serve as a reference for the flight departure time adjustment considerations of airlines. Furthermore, the estimation parameter value in passenger choice utility function for passengers to early arrival is less then to late arrivals. This shows that domestic flight passengers prefer the early arrival flight to late arrival flight under the same time difference between passenger desired departure time and flight departure time.

另由敏感度分析之结果，显示票价变动对班次承载之影响明显，而变动班次起飞时间对班次承载影响之分析，亦可作为航空公司调整其班次起飞时间之参考；此外，由旅客选择效用函数中班次时间差之参数，早到与晚到校估值的差异，以及采早到与晚到对旅客吸引时间范围不同时，其估计误差较采早到与晚到时间范围相同下小，此等结果皆显示国内旅客对於早到与晚到的感受不同。

The motion dynamics and echo models of the precessing warhead in single frequency are set up. Based on a quantitative analysis on echo spectrum and micro-Doppler modulation of precessing cone, a precession parameter estimation method by echo correlation and spectrum width is proposed. The experiments on data by simulation and darkroom measurement verify the method.

建立了单频信号下雷达观测弹头的进动模型和回波模型，通过对进动弹头回波频谱与微多普勒调制特性的定量分析，提出了利用回波相关方法和频谱展宽估计进动参数的方法，并利用暗室测量数据对该方法的性能进行了实验验证。

In the second research part of this thesis,the problem of speech enhancement is reformulated as both autoregressive parameter estimation and speech signal prediction .

论文的第二部分将语音增强问题归结为自回归参数的估计与语音信号预测联合问题。

If we still use OLS to form the model, the parameter estimation and the steadies of the model will be poor.

解决建模中的共线性问题，现有不少方法，其中偏最小二乘法是一种较为有效的方法。

He and Nina moved to California and lived at 2005 Ivar Street, Apt.

他和Nina搬到加州，并在2005年伊瓦尔街，公寓生活。

Droperidol （ potently inhibits transfected HERGchannels and this is the probable mechanism for QT prolongation.

氟哌利多有效地抑制了转染的 HERG 钾通道，可能是 QT 间期延长的机制。