查询词典 likelihood method

In order to study the effect of using maximum likelihood method on parameter identification of supermini rotating aerial vehicle, recursive maximum likelihood method was used to identify parameters of the models control function of remotepiloted controlling for unmanned aerial vehicle,and the maximum likelihood identification was introduced.

为了研究采用极大似然法进行飞行参数辨识的效果，利用递推极大似然法对超小型旋翼飞行器遥操作仿真模型控制函数的参数进行了辨识，对极大似然辨识的结果进行了动态性能分析和系统相对稳定性分析，并将其和用传统的最小二乘辨识的结果进行了对比。

The maximum likelihood function of the fatigue life was proposed based on the maximum likelihood principle, and it was born out that the maximum likelihood method could be used for the fatigue analysis.

基于极大似然原理，推导出关于疲劳寿命的极大似然函数，并证明了将极大似然方法用于疲劳分析的可行性。

Generalized linear models, which can model a large variety of data, have a wide area of application. The class of GLMs includes, as special cases, linear regression, analysis-of-variance models, log-linear models for the analysis of contingency tables, logistic models for binary data in the form of proportions and many others. Usually, the parameters in the generalized linear models are estimated by the method of maximum likelihood . But, in the literature, the nonrobustness of the maximum likelihood estimator forβhas been studied extensively. The quasi-likelihood estimator of the parameter of the generalized linear model shares the same non-robustness properties.

广义线性模型，可用于对多种类型的数据进行建模，是应用非常广泛的模型，线性回归模型、方差分析模型、用于列联表分析的对数线性模型和逻辑斯谛模型等都是广义线性模型的特例，通常，我们用极大似然的方法估计广义线性模型中的参数，但是，在文献中，对参数β的极大似然估计的非稳健性已经有了广泛的研究，广义线性模型的拟似然估计也显示了非稳健性。

Main points of the thesis are as follows:(1) The main function models and information relations between these models in the CAPP system in the integrated CAD/CAM project are explained, a new process plan design method is mentioned based on analyses of process plan design. This method is based on the process plan prototype, and develops the prototype little by little until the perfect process plan is completed, the prospect of this method is discussed;(2) The feature abstracting rules and methods are studied, a feature coding system is developed based on GT, all the defined feature models are described by the mathematical methods;(3) The integrated method of CAD/CAPP based on features is mentioned, this method defines a feature exchanging model, and develops an interface software to exchange design data into technology data base, this technology data base includes the design and technology information of the parts;(4) The process plan reasoning method based on features is created, this method uses Mycin algorithm to solve the reasoning of the feature process plan. A process plan making system is developed. In this system part process plan is made by the semi-intelligent method, this method uses the feature reasoning, feature process chain searching and man-computer talking together;(5) The main structure of the HOPE system is introduced, a shaft drawing and its process plan made by this system are shown, the data process problem in process drawing making is also discussed;(6) A new method of describing process rule is introduced, this method uses IfThen rules and neural nets weight values together to describe process rules, the BP algorithm is adopted in this method;(7) The optimal machining sequence problem of the process steps on the same fixturing is discussed, optimal algorithms SA is applied to solve this problem, the result shows that this method is more efficient than the traditional method;(8) All jobs in the thesis are summarized. In order to carry out the research in the future, some rational proposals are given.

全文论述的内容主要有下列几个方面：(1)较为系统地阐述了CAD／CAM一体化工程项目中CAPP系统的主要功能模块及其信息流程，在分析工艺设计过程的基础上，提出了基于特征原型的渐进式工艺设计方法，并探讨了该方法的应用前景；(2)研究了零件特征提取的原则和方法，在成组技术的基础上，开发了一套基于特征的分类编码系统，并在提取零件特征的基础上，定义了零件特征的数据模型，开发了基于轴类零件特征的参数化设计系统；(3)研究了基于特征的CAD／CAPP集成的方法，通过定义零件特征数据模型的存储结构，开发了将设计数据转换到工艺数据库中的接口程序，为后续的CAPP系统提供必要的零件形状和工艺信息；(4)研究了基于特征的工艺推理方法，将Mycin算法应用到工艺决策中，开发了基于特征的工艺推理及工艺方案生成系统，在系统中综合运用特征推理、特征加工工艺链查询及人机对话相结合的半智能化方法确定零件加工工艺；(5)介绍了整个HOPE系统的总体结构，通过运行HOPE系统绘出了一轴类零件的零件图，并生成了该零件的加工工艺方案，初步探讨了基于特征的工序图生成技术中数据处理问题；(6)研究了工艺设计过程中知识如何有效表示的问题，提出了将显式的IF-THEN规则表示与隐式神经网络权值表示相结合的工艺知识表示方法，并利用BP算法进行了工艺知识表示的初步研究；(7)研究了工艺设计过程中同一安装下工步优化排序问题，利用神经网络中基于模拟退火的理论来解决该工步优化排序问题，实践证明该方法较传统的算法具有更高的效率；(8)总结了本文所进行的研究工作，为今后进一步开展工作提出了较为合理的建议。

Based on the invariance of maximum likelihood estimation, the sufficient and necessary condition under which the maximum likelihood estimation has invariance for the parameters are given, then it uses this conclusion to calculate the maximum likelihood estimation of σ^2 and ρ for bivariate normal distribution.

根据参数极大似然估计不变性原则，给出在一定条件下极大似然估计具有不变性的充分必要条件，并利用该结论计算了二元正态分布Z=的未知参数σ^2和ρ的极大似然估计值。

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。

This train classifies "information carrier adhering to the build" as design elements, and probes into integrated design method of it and single building separately: method of definite position, method of definite form and method of combination; Then, this train probes into integrated design method of it and colonys building , that bases on the cognitive design method: method of rhythm controls,method of node outstanding, and that aims at the design method to protect: method of protect original, method of repairing and method of renewal.

本文的第四部分提出了一体化设计的思路，将建筑附着信息载体作为设计元素，探讨了它与建筑单体一体化设计的方法：定位法、定形法、混合法；以及它与建筑群体一体化设计时，基于认知的设计方法：节奏控制法、节点突出法，旨在保护的设计方法：存真法、修缮法、更新法。

The proposed method is based on a higher order likelihood-based asymptotic procedure. The merits of the proposed method are numerically compared with the signed log-likelihood ratio statistic and the simple t-test method with respect to their expected lengths, coverage probabilities and type I errors.

我们所利用的方法是以概似函数为基础的高阶近似方法，并且我们利用模拟的方法去跟signed log-likelihood ratio及 simple t-test 两种方法比较所建构出的信赖区间的覆盖机率和平均宽度以及所对应检定的型I错误来检视我们所利用方法的优劣。

First, a method for calculating semantic likelihood between two phrase is carried out. then use the likelihood to determine the title row or column of the table, the correlation between titles and fields is determined at the same time. base title of the table, a simply method is presented which can be used to calculate correlativity between this table and what we wanted to extract.

首先提出了一种短语语义相似度的度量方法，然后利用短语语义的相似度确定表格标题行，并对表格行与抽取字段的对应关系进行计算，最后计算表格的整体语义，度量该表格与所要抽取的内容有多大相关度。

A Special Maximum Likelihood method for building mathematical models in dynamic calibration is proposed, which is a kind of maximum likelihood method with a special noise model.

提出了误差估计表达式以及在带宽有限测量假设条件下，辨识离散时间模型时，采样频率的选择与模型辨识误差的关系。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。