查询词典 parameter estimation

The main contents is: analyzing some detection method to moving target nowadays; particular studying the principle of detection moving target in SAR; analyzing SAR imaging theory and the echo model of moving target; discussing conventional SAR imaging , the movements of target cause the changes of doppler mass center and regulable frequency, and the changes cause effect the imaging result; introducing the estimation method of doppler parameter; analyzing theory of DPCA, derivating the formula needed, and validating it's validity and practicability through simulation; advancing the improved DPCA algorithm that combine the advantage of DPCA and ATI, and validating it through computer simulation; using the revision algorithm to range ambulate based on keystone transformation, and validating it through computer simulation; discussing the compensation art of SAR imaging.

主要内容有：分析了现有的一些动目标的检测方法；详细研究了SAR动目标检测的原理；分析了SAR成像理论和运动目标的回波模型；探讨常规SAR成像时，目标运动引起的多普勒质心和调频率变化，以及这些变化对成像结果的影响；介绍了多普勒参数的估计方法；分析了DPCA原理，推导所需要的基本公式，并仿真验证其有效性和实用性；提出了结合DPCA和ATI优点的改进DPCA算法，并仿真验证；探讨了SAR成像中的运动补偿技术。通过对仿真结果的分析，本文提出的方法具有一定的指导意义和参考价值。

Methods: Using the time series of cucumber downy mildew disease, we established an autoregressive integrated moving average model, ARIMA(2,2,0) based on model identification, comparison of residual variance, estimation and verification of parameter, observation of the correlation of the estimates matrix, autocorrelation check of the residuals, analysis of the fitting of model and so on.

采用黄瓜霜霉病病情指数时间序列进行研究，通过模型识别、残差方差比较、参数估计及其检验、观察参数之间相关系数矩阵、白噪声检验、模型的拟合度分析等过程。

Furthermore, a motion estimation technique for sequential thermal images is presented which measures the parameters of global motion in the image plane due to zoom and pan of the camera or the process of the vehicle, and a motion compensation interpolation technique is also presented which can compensate the global motion. The algorithm is based on a three-parameter model for motion description, and some improyement is given in this method. Good results are shown in the computer simulation experiments.

在研究了帧内编码的情况后，本文进一步分析了序列图象的特点，并对由摄象机运动和车辆行进所造成的全局运动进行了运动估值和补偿研究，对现有的三参数估值算法进行了分析和改进，推导出热图的序列图象的平移及缩放的运动估值与补偿的公式，通过计算机模拟进行了全局运动的估值和内插实验，获得了较好的结果。

The fourth chapter in this paper introduces the modeling ideas of stochasticvolatility into panel data model and puts forward panel data stochastic volatilitymodel. The Kalman Filtering can be employed to filter out the quasi-likelihoodfunction of the model and quasi-maximum likelihood estimation is used as achief means of estimating the parameter of the model.

第四章则将随机波动建模思想引入平行数据模型，提出平行数据随机波动模型，运用卡尔漫滤波方法得到模型的伪似然函数，进而采用极大似然估计方法求解模型参数。

Full pipeline through tensor estimation,DTI parameter image computing,tensor field visualization,fiber tracking and visualization procedures are implemented.

该系统提供了从扩散张量图像的估计重建、各种导出参数图像的生成、张量场可视化和纤维跟踪与可视化在内的完整的DTI处理与分析功能。

On the base that has mensurable estimation to hemal three-dimensional motion, extraction gives important athletic parameter, the amplitude that is like athletic way, displacement and athletic contrail.

在对血管的三维运动进行定量估计的基础上，提取出重要的运动参数，如运动方向、位移的幅值和运动轨迹等。

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 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 data processing method of metalized capacitor life expectancy and GLUE method of parameter point estimation of Weibull distribution are introduced in the course of analyzing.

分析过程中介绍了威布尔分布的金属化电容器寿命数据处理方法和威布尔分布参数点估计的GLUE方法。

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。