empirical frequency 中文意思是什麼
empirical frequency
解釋
經驗頻率-
By making some assumptions, collision frequency were presented. then the the flocculation kinetics model was established through population balance equation. comparison of experimental data and modeling results indicate that there are the same trend between the two. so the model can predict floes number and size during flocculation of yellow river ' s loess particles without using empirical parameters. the tem and sem were used to obsever floes in the study of floe structure. the flocculation was divided as flocculi, floc and floe aggregate. the floes structure model was established by assumption that particles position in floe accords with tetrahedron. the fractal dimension of model and experimental floes was found to be coincidentso the model can reflect the structure of flocs formed in flocculation of yellow river ' s loess particles by macromolecule flocculant at a certain extent
最後，本文還對絮凝動力學和絮體結構進行了研究，在前人研究的基礎上，針對高分子絮凝黃河泥沙，對絮凝過程作了一些符合試驗條件的假設，建立了顆粒碰撞頻率表達式，應用了顆粒數量平衡方程，從而建立了絮凝過程的動力學生長模型，模型計算結果與試驗數據對比表明，二者趨勢一致，在沒有使用經驗參數的情況下基本上能夠描述黃河泥沙絮凝過程中絮體數量和尺寸分佈的變化過程；對絮體結構的研究中，應用掃描電子顯微鏡和透射電子顯微鏡對絮體進行了觀察，將絮體分為絮粒、絮團和絮網三個不同的生長階段，通過假設顆粒結合位置符西安建築科技大學博士學位論文合正四面體，建立了絮體結構模型，計算得到的模型絮體分形維數基本與試驗中的實際絮體相符，在一定程度上能夠反映高分子絮凝黃河泥沙生成的絮體結構。 -
The empirical analysis, using probit model, showed that the extension efficiency of the technique was obviously affected by following factors : income and cost, yield increase, farmers " age and education, non - agricultural income, farmer ' s social status, distance from town, frequency of farmers " contact with media and agricultural technicians
運用probit模型對超高茬麥田套稻技術推廣的影響因素進行分析，結果顯示畝增收節本、畝增產量、戶主年齡、戶主受教育時間、非農收入、是否幹部、離鎮距離、媒介頻率、與農技人員接觸次數對該技術的推廣有顯著影響。 -
An empirical analysis is made with the population data of the us cities to verify the theory and models developed in this paper, which will contribute to reconcile the apparent difference between the hierarchical step - like frequency distribution of city sizes suggested by central place theory and the smooth curve reflected by the work on the rank - size rule
多重zipf維數模型不僅可以有效地統一中心地的等級階梯與位序-規模法則反映的連續分佈，而且可以揭示城市體系演化的更多信息和隱含法則。以美國城市體系1998年的數據為實證對象，給出了城市規模分佈的多分維 -
We present two different frameworks to analyzing the high frequency time series : first, regularly spaced sampled observations, which is sampled with interval of one hour, one minute even one second ; secondly, the irregularly spaced data, such as transaction by transaction data 。 the main work and innovations of the dissertation include : 1. through empirical research of high - frequency time series of shanghai composite index, the paper researches the different statistical properties on different frequency
高頻時間序列的分析與建模是金融計量學的一個全新研究領域。金融市場中高頻時間序列分為兩類:一類是采樣間隔相等的數據，比如一小時、十分鐘、五分鐘、甚至是以秒為單位採集的按時間先後排列的等時間間隔的數據;另一類是指對交易過程實時採集的數據，也就是每筆交易的數據（顯然是不等間隔的數據） 。 -
On the basis of the steady - state semi - empirical model of the tire and the concepts of the relaxation length and the effective slip ratio, a non - steady semi - empirical model to express the tire longitudinal - slip response to the low - frequency input of the transient vertical load and transient slip ratio was presented
摘要在穩態半經驗模型的基礎上，根據鬆弛長度和有效滑移率的概念建立了能表達時變垂直載荷及時變滑移率低頻輸入下的輪胎縱滑特性非穩態半經驗模型。 -
In the second, in allusion to non - stationary the characteristic of the signal, the author introduces to the method that using empirical mode decomposition to analysis the vibration signal so that the signal are made up of some intrinsic mode function, after this process, we can use stochastic subspace identification to identification the mode parameter of the structure and find the same work frequency
其次，針對氣閥振動信號的非平穩特點，本文採用了經驗模式分解法（ empiricalmodedecomposition ）對振動信號進行分析處理，使之成為若干個基本模式函數imf （ intrinsicmodefunction ）和一個殘余量的線性組合。接著採用隨機子空間參數識別法對各個基本模式函數其進行結構參數識別，同時找出各種狀態的共同工作頻帶。 -
Therefore, research on improving the image resolution of sar and isar continuously has been a hot as well important topic. time series echo signal can be decomposed to imfs ( intrinsic mode function ) by emd ( empirical mode decomposition ) algorithm, which is distributed following frequency
經驗模態分解（ emd : empiricalmodedecomposition ）方法能夠把時間序列信號分解成有限數目的本徵模態函數（ imf : instrinsicmodefunction ） ，分解結果按頻率高低分佈。 -
Time - frequency reassignment method based on empirical mode decomposition and the application to fault diagnosis
基於經驗模式分解的時頻重排方法及其應用 -
The results of emulation and practical technical application indicate that time sequence components observed by empirical mode decomposition algorithm and frequency spec trum of them can reflect partial failure signature of gear adequately, at the same time, the weak signal feature can be easily extracted from them
模擬研究及實際工程應用表明，採用經驗模式分解演算法后得到的時序分量及其頻譜能夠很好地體現齒輪局部故障特徵，具有很強的弱信號特徵提取能力。 -
First of all, the emd - based wavelet threshold denoising algorithm is apllied to denoise noisy structural response data to reduce the effect resulting from noise. during the process of the empirical mode decomposition ( emd ), the two boundaries of the response signal are processed with semi - periodical ? semi - symmetrical method. subsequently, hilbert - huang transform ( hht ) is used in identifying structural intrinsic frequency
這套技術用以解決實際工程應用中遇到的在信噪比較低情況下通過結構的響應信號來進行結構損傷識別問題，即先用基於emd的小波閾值去噪演算法對含噪結構響應進行去噪處理，以有效降低噪聲影響（在去噪的emd處理過程中，對信號的邊界採用「半周期半對稱」延括演算法來抑制邊界誤差） ，然後再用希爾伯特?黃變換（ hht ）進行結構的固有頻率識別，最後計算出結構剛度。 -
By experiment, we found that the variation of gear case radiant efficiency with frequency keep accordance with that of simple one as a whole, but the radiant efficiency of gear case will go beyond any calculation result of empirical formula when the frequency is below 250hz. we also found that stimulation changes affect radiant efficiency little by varying speed experiment, and it can be ignored in engineering calculation. the rectangle structures as gear case, possess characters of both plane and ball, and their sound radiant efficiency lie between plane and ball region
通過試驗發現，總體上變速箱輻射效率隨頻率的變化規律同簡單構件的輻射效率是一致的，但在250hz以下的低頻區域，變速箱的輻射效率大大高於任何一個經驗公式的計算結果；通過換檔試驗發現，激勵的改變對輻射效率的影響不很顯著，工程計算可以不予考慮；對于變速箱這類三個方向尺寸差別不大的結構，其輻射性質具有平板和球源的雙重特徵，輻射效率介於平板和脈動球源之間，據此提出在工程應用時可以取平板和脈動球源輻射效率的平均作為此類結構輻射效率的觀點。
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