Research on application of modified maximum likelihood method in wave field overlapped by incident and reflected waves 改進的最大似然法在入反射波合成波浪場中應用研究
There are three frequently used method : distance method , maximum parsimony method , and maximum likelihood method 目前常用的構建發生樹的方法有三種,即距離法、最大簡約法和最大似然法。
Two objects functions were deduced , which of the maximum likelihood method and the conventional bayes " method , with the application of principle of maximum entropy . under the information theory , more applications are provided to those back analysis methods 論文應用最大熵原理推導了最大似然法和傳統貝葉斯法的準則函數,從信息論的角度為這兩種反演分析方法的發展開拓了更廣闊的應用空間。
This paper presents that the directional spectra and the reflection coefficients of the oblique and the multidirectional irregular waves on the co - exist wave field of incident wave and reflected wave have been studied . a modified two - points method is proposed that can be used to calculate the frequent spectrum and reflection coefficient of the oblique waves . for the multidirectional irregular waves , the directional spectra and reflection coefficients are obtained by the modified bayesian directional method and the modified maximum likelihood method 本文研究了入、反射波共存場中斜向不規則波和多向不規則波波浪場的方向譜和反射系數,對于斜向不規則波頻率譜及反射系數的計算提出了一種改進兩點法( mtpm ) ,對于多向不規則波方向譜和反射系數的分析,應用了改進的貝葉斯方法( mbdm )和改進的最大似然法( mmlm ) 。
Phylogeny analysis is performed with phylip software package and encoding sequence of bdnf gene . the phylogeny trees have been drawn with three different methods ( maximum parsimony method , genetic distance method and maximum likelihood method ) , respectively . the analysis outcomes are not all consistent for the reason that it is closely related to the selected methods and the conservative level of the sequences 采用不同的統計學分析方法,最大簡約法( maximumparsimonymethod ) 、最大似然法( maximumlikelihoodmethod )和遺傳距離法( geneticdistancemethod ) ,得到了物種系統發育進化樹,但拓撲結構并不完全一致,這是可能是因為分子系統學研究與采用的分析方法和所選基因的保守程度即作為分子標記的可信度密切相關。
A new heuristic search method is devised for maximum likelihood method , which first constructs a starting tree , and then through branch swapping searches for trees best resembling the present optimal tree and locates a better tree . repeat this process , till no more better trees are generated or the upper iteration limit is arrived and the program ends 對最大似然法,改進了一種新的啟發式搜索:隨機建立一棵初始樹,然后通過查看與當前最優樹拓撲最近的樹,從中尋找更優樹,不斷地更新當前最優樹,直到無法找到更優樹或者達到了搜索次數的上限,算法停止。
There are mainly two type of algorithms used for spatial spectrum estimation : one is those based on bayesian maximum likelihood method , like the ml ( maximum likelihood ) algorithm , maximum entropy method and etc . , the others are based on the spatial decomposition or projection of correlation matrix , this kind of algorithm include vector characterization method , music ( multiple signal classification ) algorithm , projection matrix method , etc . music is a classical spatial spectrum estimation algorithm that has a super high resolution and is widely used today , however , it cannot estimate doa of signals that are correlated 空間譜估計的算法大致分兩大類:一是基于極大似然估計和最大后驗概率估計統計理論的算法,包括:極大似然估計法( ml ) 、最大熵法等;另一類是基于對協方差矩陣進行子空間分解或投影的算法,包括:矢量特征法、多重信號分類法( music ) 、投影矩陣法等。其中, music法是一種經典的空間譜估計主流算法,具有超強的分辨性能,但它無法實現對相干信號進行測向分辨。
Abstract according to the defect of the conventional bayes " method in the geomechanical engineering back analysis , expanding bayes " method was established in this paper . with the applications of the probability theory and the mathematical statistics principle , the geomechanical engineering random back analysis objects function was founded based on the aic criterion of the decision information theory and the maximum entropy criterion , a the matching question between the observed information and the previous information of the conventional bayes " method were proposed . in addition , the least square method , maximum likelihood method and conventional bayes " method were unified in form 本文針對巖土工程反分析中使用的傳統貝葉斯法中存在的缺陷,提出了擴展貝葉斯法,從概率論和數理統計的原理出發,建立了基于決策信息論中aic準則和最大熵準則的巖土工程隨機反演的準則函數,解決了傳統貝葉斯法的觀測信息與先驗信息的匹配問題,并從形式上完成了目前常用的最小二乘法、最大似然法及傳統貝葉斯法準則函數的統一,并可由觀測數據的質量和數量進行預測模型的辨識。
Before using phase - only algorithm to achieve nulling , estimations of the number of interferential sources and the doa of interferential signals are needed . so , the spatial spectrum estimation basd on the maximum likelihood method ( capon method ) and music algorithm used for detecting the number of interferential sources and the doa of interferential signals are discussed in the second chapter 在采用phase - only算法進行波束置零之前,需要估計干擾源的方向和個數,因此本文還在第二章介紹了發射數字波束形成中用于測定干擾源個數和方向的空間譜估計法? capon算法和music算法的測向原理,并分析了它們的性能和優缺點。