查询词典 method of undetermined coefficients

The common method, that all strong-correlation terms of the model are eliminated, can bring the loss in the engineering application, so the new method is proposed that the identified model reserves some correlation. The augmented matrix A is constructed by the outputΔW and the matrix S. The"determinating order based on ratio of determinant"is brought out to screen the strong-correlation terms in the structure identification. The latent root estimation is improved in screening the eigenvalues and eigenvectors. Thus the estimation precision is improved greatly.The consistence check of guidance instrument error coefficients of flight test and ground test is the purpose of flight experiment. The causes of inconsistency of the two models are analyzed. The hypothesis test of linear regression model based on F statistics is proposed to check the consistence.Finally, the instability of error coefficients is probably caused by the change of the flight environments, therefore, the relation between the error coefficients and flight environment is analyzed. The approach is presented to identify SINS guidance instrument error models and compensate the error in the segmented sections corresponding to the change of vertical acceleration of aircraft.

在结构辨识中，常用的方法由于将模型中的强相关项全部剔除而给工程应用带来损失，因此，本文提出了新的有益思想，即在保留一定相关性的基础上进行辨识：将输出向量ΔW与环境函数矩阵S构成增广矩阵A，然后采用"比定阶行列式"来剔除相关向量的方法，这样既可以尽可能多地保留了对落点影响大的强相关参数，又可以对落点影响小的强相关参数给予剔除；在参数估计中，改进了特征根估计中特征根和特征向量的筛选方法，提出"近零"准则，从而大大提高了参数估计的精度；再者，鉴于天地模型"一致性"检验是飞行试验和SINS制导工具误差系数分离的主要目的，因此，本文又深入分析了造成天地模型不一致的原因，提出了采用基于F统计的线性回归模型假设检验方法来进行捷联制导工具误差模型的天地"一致性"检验；最后，鉴于飞行环境剧烈变化可能会对惯性仪表误差系数稳定性带来一定的影响，因此本文深入地分析了SINS制导工具误差系数与外界环境的关系，提出了基于过载变化大小的分段辨识和分段实时补偿的算法。

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。

In this paper Ⅰ successfully applied these methods to fault diagnosis, and presenting some new innovative machinery fault diagnosis method; First Ⅰ present a new gear wornout fault diagnosis method, this method use the vibration signal's time-frequency attribute and instantaneous phase undulation to accurately detect gear's fault, and by comparing with the traditional frequency domain analysis method, this method reveals that many nonlinear and nonstationary characteristic exist in gear's vibration, this tell us that if we use frequency domain analysis method without pay attention to the signal's characteristic, we could get wrong diagnostic result; Then Ⅰ present a new bearing fault diagnosis method, this method use ATVFD and Hilbert transform to do envelop demodulation,Ⅰ analyze the envelop with time-frequency method and find out that this method is more accurate then traditional method.Ⅰ also explain that the modulation of the fault to the carrier wave may also be non-stationary and nonlinear; Finally Ⅰ present a cylinder pressure measurement method of diesel engine by means of vibration, cylinder pressure is an important parameter of diesel engine fault diagnosis, the pressure measuring is simplified a lot by this method,Ⅰ also use the ATVFD and time-frequency analysis to realize it.

本文中将上述理论方法成功地应用到故障诊断中去，提出了几点创新性的诊断方法；提出了一种齿轮磨损故障诊断的新方法，该方法利用振动信号能量的时频域分布特征与瞬时相位波动特征可以进行精确的齿轮故障诊断，并通过与传统的频域诊断方法的比较，揭示出齿轮振动中存在的明显的非线性与非平稳特征，说明了不加选择地利用频域分析方法进行齿轮故障诊断很可能会得到错误的诊断结果；提出了一种轴承故障诊断的新方法，该方法利用ATVFD分解与Hilbert变换进行包络解调，并对解调得到的包络信号进行时频域分析，可以实现更加准确轴承故障诊断，说明了故障对载波信号的调制往往也是非平稳与非线性的；提出了一种利用振动信号进行柴油机汽缸内压力检测的新方法，柴油机汽缸压力的变化是柴油机故障诊断的重要参数，利用振动方法可大大简化汽缸压力的检测过程，该方法也是综合利用ATVFD分解与时频域分析方法实现的。

According to the restrictive conditions, the closed domain of modification coefficients are gotten. Modification coefficients can be remodified and adjusted with the use of CAD method, and the proper modification coefficients can be obtained finally.

根据约束条件规划出变位系数的封闭区域，借助计算机辅助手段来求取符合条件的变位系数，并可进行重复修改、调整，最终得到满足要求的变位系数。

Since the multiple scattering should be considered, the scattering problem of many-cylinders is more complicated than single cylinder. By using scattering matrix method to solve the scattering problem of many-cylinders, first we have to express the incident fieldand scattered field by special function（for example, Bessel function and Hankel function）under cylindrical coordinate, then use the addition theorem of special function to get a linear system of equations to relate the incident field coefficients and scattered field coefficients. The incident and scattered field coefficients for every cylinder can be solved from the linear equations by matching electromagnetic boundary condition pointwisely.

单颗圆柱散射体的散射场解析解很早就被解出，而多个圆柱阵列的散射场问题因为涉及到入射光在圆柱与圆柱间的多重散射，故散射行为较单颗圆柱的散射复杂，因此圆柱阵列的多重散射问题需要利用加法定理来处理；散射矩阵法的主要精神即是先用圆柱座标下的特殊函数对平面波和圆柱散射体的内外域电磁场做无穷级数展开，再藉由特殊函数的加法定理将所有圆柱散射体的展开中心移到同一个展开中心，最后可以得到一组连结整个散射系统的入射电磁场系数及散射电磁场系数的线性方程组，将该组线性方程配合电磁场在散射体边界的连续条件，便可分别求出圆柱阵列中各个圆柱体的内部电磁场与外部散射场，再利用线性叠加原理即可求得整个圆柱系统的全域电磁场分布。

In this paper, a speckle reduction method for SAR images based on Dual Tree Complex Wavelet Transform is proposed. It first presumes the probability distribution function for complex wavelet coefficients of the original nature image, and then applies MAP theory to estimate coefficients from the noisy wavelet coefficients. Filtered image can be derived after inversed DTCWT.

该方法首先对无噪声污染图像的复数小波系数的统计概率分布进行建模；然后利用此先验概率模型，采用最大后验概率方法从含噪小波系数中估计出无噪声污染的小波系数：最后经重构得到滤波后的图像。

Then, incomplete beta function is applied to enhance the image′s global contrast in the low frequency subband, and nonlinear gain function is used to process the coefficients at each scale in the directional bandpass subbands respectively, which suppresses small coefficients and enhances big coefficients by threshold denoising method.

引入非完全贝塔函数对低频子带系数进行处理，提升图像整体对比度；采用非线性增益函数对各带通方向子带系数进行处理，通过估计噪声水平设定阈值，抑制绝对值小于阈值的系数，增强大于阈值的系数。

The heat generation curves of seven rubber materials used in tires with the changes of temperature have been obtained by using Dynamic Mechanics Analysis technique on NETZSCH DMA242 instrument, knowing that the heat generation of every other rubber materials except inner liner rubber changes lightly alone with the temperature within 10℃～80℃. According to the Fourier law, the heat transfer coefficients of tire rubber are measured by stable method on self-made experiment instrument. The coefficients changes lineally within 20℃～80℃ and the relation formulas λ=λ〓+bt are given out attached with λ〓 and b. The specific heat of tire rubber are measured on Differential Scanning Calorimeter NETZSCH DSC204 and the relations with temperature are linear and the formula is c=c〓+bT, where c〓 and b gained from experiment result data are presented in the paper. The heat convection coefficients on the surface of rolling tire are measured according to the principle of heat-mass transfer analogy principle after simplifying rolling tire into rotating disk with straight movement on wind channel. The relation with rotation speed of disk is linear as h=5. 399+0.0258n and the relation with straight line speed of tire is linear too, h=

论文采用动态力学分析技术，使用NETZSCH DMA 242型实验仪，获得了轮胎用七种胶料的生热率随温度变化曲线，确知除内衬层胶以外，其它各种胶料在一般胎温范围内（10℃～80℃）的生热率随温度变化不大；轮胎胶料的导热系数根据傅立叶定律的基本原理，采用稳态法在自行搭建的实验台上进行测试，结果表明，材料的导热系数在20℃～80℃的温度范围内随温度呈线性变化，论文给出了各种材料导热系数的线性变化的关系式λ=λ〓+bt及其λ〓和b的值；轮胎胶料的比热运用差式扫描量热原理，在NETZSCH DSC204型DSC实验仪上进行测试，结果表明，胶料的比热随温度的变化呈线性变化，其关系可用c=c〓+bT表示，文中给出了根据实验数据拟合的c〓、b的值；对轮胎表面的对流换热系数的测定，本文先将滚动的轮胎简化为有直线运动的旋转圆盘，而后采用萘升华热质比拟技术，在风洞中测量了滚动轮胎表面的对流换热系数，结果表明，圆盘表面对流换热系数与转速呈线性关系，即h=5.399+0.0258n，轮胎表面对流换热系数与其直线运动的速度呈线性关系，即h=

The current coefficientΨ of correction includes many influencing factors. And numerical value of this coefficient varies widely. So the current method was improved from one coefficient to four coefficients in this paper. Three new coefficients of correction were considered to decrease composite ratio of coefficient Ψ and put forward three coefficients to modify calculating result.

针对现行经验系数包含的影响因素太多以致其取值过于离散的问题，在现行规范法计算建筑地基沉降的基础上，对现行方法进行了改进，由原来的1个修正系数改为4个修正系数，用新增加的3个系数反映3个不同方面的影响，以减小原经验系数的综合程度。

The every frame image was transformed by dyadic discrete wavelet and the characteristic of wavelet transform coefficient was analyzed. Low frequency coefficients were analyzed by fast principal component method which quoted Gram-Schmidt orthonormalization procedure in fixed-point algorithm then distilled principal component and reconstructed the low frequency coefficients. To suppress image noise, the high frequency coefficients were equated to zero.

该算法对热图像序列中的每帧图像进行二进制离散小波变换，提取出低频部分的系数；对低频系数进行改进PCA分析，通过固定点算法并引入Gram-Schmidt正交化过程求解特征向量；令高频系数为零，抑制图像的噪声。

Vishnu entered a dark fourth dimensional dream that did not support his field or continued life.

毗瑟挐进入了一个第四密度的黑暗梦想，那里并不支持他的能量场或继续生命。

Leaders and decision-making persons use it to collect the data, including the information of unit work, handing in fee, oweing fee, prepaying fee,changing and afterpaying and account transfering of joining-insurance employee, and account paying of all kinds of insurances from hospitalization insurance institutions.The collected data is picked up, organized, switched and showed to user.

该子系统主要面向各级领导、决策分析人员；从各个医疗保险经办机构和定点医疗机构采集数据，包括在各个医疗保险经办机构处理的单位办公信息，单位缴费、欠费、预缴费信息，参保职工变更信息，参保职工增减变动信息，参保职工补缴信息，参保职工帐户划拨信息：包括各定点医疗机构处理的各险种帐户支出信息，各险种的统筹金支付信息等；将采集的数据提取，组织和转换，然后展示给用户。