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frequency distribution

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frequency distribution 【統計學】頻數分布；頻率分布。

【統計學】頻數分布；頻率分布。 “frequency“ 中文翻譯：   n. 1.屢次，頻仍，頻繁。 2.(脈搏等的)次數，出現 ...“distribution“ 中文翻譯：   n. 1.分配，分發，配給；分配裝置[系統]；配給品；配 ...“distribution frequency“ 中文翻譯：   分布頻率“amplitude frequency distribution“ 中文翻譯：   振幅頻譜“amplitude-frequency distribution“ 中文翻譯：   振幅頻率響應; 振幅頻譜“analysis of frequency distribution“ 中文翻譯：   頻率分布分析“binomial frequency distribution“ 中文翻譯：   二項式頻率分布“bivariate frequency distribution“ 中文翻譯：   雙變量頻 率分布(記錄兩個變量頻率的一種統計學圖表)“circular frequency distribution“ 中文翻譯：   圓周頻率分布“comparison of frequency distribution“ 中文翻譯：   頻數分類比較“composite frequency distribution“ 中文翻譯：   合成頻率分布“compound frequency distribution“ 中文翻譯：   復合次數分配; 復合喇叭; 復合頻率分布; 復合頻數分布“cumulative frequency distribution“ 中文翻譯：   累積次數分配; 累積頻數分布; 累積頻數分配; 頻率累積分布“curve of frequency distribution“ 中文翻譯：   頻率分布曲線“discontinuous frequency distribution“ 中文翻譯：   非連續性頻數分布“distribution of frequency curve“ 中文翻譯：   頻數曲線分配“empircal frequency distribution“ 中文翻譯：   經驗頻率分布“frequency cumulative distribution curve“ 中文翻譯：   頻率累積分布曲線“frequency distribution analyse chart“ 中文翻譯：   頻率分布分析表“frequency distribution curve“ 中文翻譯：   次數分布曲線; 頻次分配曲線; 頻率分布曲線“frequency distribution diagram“ 中文翻譯：   頻次分布圖; 頻率分布圖“frequency distribution function“ 中文翻譯：   頻率分布函數“frequency distribution histogram“ 中文翻譯：   頻率分布直方圖“frequency distribution table“ 中文翻譯：   次數分配表; 頻數分布表“frequency size distribution“ 中文翻譯：   頻率分布

frequency divider

On the basis of investigation and research about the technology of reconstruction for ict image up - to - date , this paper is devoted to develop an algorithm for image reconstruction based on wavelet theory . in this paper , time - frequency distribution for spatially varying filter was used to construct convolve - kernel by dwt , to modify convolve - back - projection algorithm 本文在國內外有關ct圖像重建的研究狀況基礎上，根據小波分析理論，利用小波變換在時頻空間的可變性，用dwt變換構造卷積核，對卷積反投影算法做了改進。

Our results showed as follows : 1 ) the spl and rsal polymorphisms of the collagen type 1 alpha 1 ( col1 al ) gene , the - 174g / c promoter polymorphism of the interleukin - 6 ( il - 6 ) gene , the asn363ser polymorphism of the glucocorticoid receptor ( gr ) gene , and the t ? c polymorphism in intron 5 of the transforming growth factor pi ( tgf - p ! ) gene are absent or too rare in chinese . compared the polymorphisms of these five markers with other populations using % 2 test and fisher ' s exact two - tailed test , significant differences of allele and genotype frequency distributions were observed at these polymorphisms ( p < 0 . 001 ) 結果表明： 1 )白介素6 ( il ? 6 )基因的? 174g c多態性、型膠原蛋白_ 1 ( col1a1 )基因的sp1和rsa多態性、轉化生長因子_ ( tgf - _ 1 )基因的內含子5t c多態性和糖皮質激素受體( gr )基因的asn363ser的多態性在中國人群中均未發現或者多態性很低； x ~ 2檢測和fisher精確(雙尾)檢驗比較這些多態性的頻率，發現在中國人群與其它種群或人群中，等位基因和基因型存在顯著的差異( p 0 . 001 ) 。

In this thesis the problem of feature extraction and fault diagnosis is addressed using wavelet , time - frequency distribution and bispectrum of non - stationary , non - gauss vibration signals . the application of discrete and continuous wavelet transform to gear vibration signal feature extraction and fault diagnosis is investigated . an efficient fault diagnosis system based on discrete wavelet transform and artificial neural network is presented , which can accurately estimate gear fault advancement 為此，本文利用非平穩、非高斯信號處理理論中最受關注的小波變換、時頻分布和雙譜理論，對非平穩、非高斯的機械振動信號的特征提取與故障診斷問題進行了深入而全面的研究。

Second , this paper analyzes the time - frequency distribution of the clutter from airborne pulse doppler radar ( pdr ) . the side - lobe clutter , which is the main factor to influence the pdr , is analyzed and calculated . based on the simulation of typical geometry of the land , we analyze and discuss the side - lobe clutter and concluded that the dft of can be considered as the phase of the coho 并且根據各種典型地貌的近似模擬，從統計特性上和頻率域上對脈沖多卜勒雷達的旁瓣雜波進行了分析討淪，還得出脈沖多卜勒雷達的dft可以近似地看作相參積累，并在程序的編制中利用了這一個結論。

In the aspect of blind - identification , the mutual power spectrumx time - frequency distribution product of two delay signals are used as the features of classification . the cluster analysis and cumulant invariants of mpsk signals are used to automatically classify communication signals 在信號識別中，選取信號的互功率譜、時頻分布、 mpsk信號的延遲相乘信號作為分類特征，利用模式識別中的聚類分析以及mpsk信號的基于高階累積量構成的分類特征不變量實現了信號調制類型的自動分類。

By the use of “ radar target backscattering simulation software ” and through many flight mode and research mode experiments with the u . s . - made helicopter ah - 64 as an example , a detailed analysis of helicopter echoes ’ time , frequency domain and time - frequency distribution characteristics is made . finally , according to these features , a tentative plan to detect hovering helicopters is proposed 本文利用專門的電磁仿真軟件，以美制“阿帕奇”直升機為例，詳細分析了直升機雷達回波的時域、頻域和時頻分布的特性，并根據這些特點提出了雷達探測武裝懸停直升機的初步方案。

The other research purpose is to discover characteristic information and reliable methods of reflecting spinal cord damage . due to typical damage indicators , amplitude and latent period , have bugs such as limited information and weak stabilities , this project recommends applying time - frequency analysis to monitoring spinal cord function . through analysing and comparing typical signal with stft and cwt , it is proved indicators under time - frequency distribution can be better in reflecting signal changes , espcially the wavelet transformation 針對目前ep監測中判定脊髓損傷的指標（波幅和潛伏期）存在信息量相對較小、穩定性較差的缺陷，本課題提出利用時頻分析技術對術中脊髓功能監護進行研究，通過短時傅立葉變換和小波變換分析和比較典型信號的時頻分布，證明時頻特征參數能更有效的提取信號的變化信息。

2 ) the concept of space frequency distribution is introduced into reevaluation of incoherently distributed source model . based on the model , two low - complexity robust bearing estimators are developed . it is proved theoretically that their estimates are asymptotically unbiased and consistent 2 )從空間頻率分布的角度重新評價了非相干分布源模型，提出了兩種低計算復雜度的穩健的分布源波達方向估計器，并從理論上證明了它們的漸近無偏性和漸近一致性。

Joint time - frequency analysis technology is proposed in focusing imaging instead of traditional range - doppler method . it could apparently improve the image quality . time - frequency resolution and cross term interference of some kinds of typical time - frequency distribution are analyzed in the dissertation 分析比較了幾種典型的時頻分布的時頻分辨率和交叉項干擾問題,并通過仿真證明了時頻綜合方法和重排理論能得到更優的isar圖像。

For multicomponent chirp signals with unbalanced amplitudes , an iterative algorithm combined with the paf is proposed to suppress the error propagation effect and residual signal in the peeling - off procedure . the corresponding time - frequency distribution for unbalanced signals is derived 針對多分量強弱信號,引入基于逐次減小誤差的迭代算法,導出了能夠減小強弱信號相互影響的核函數設計方法,從而有效抑制誤差傳播和殘余信號。

The main work and originality in this paper can be summarized as below : 1 . studies on the cross - components in the wigner - ville distribution of multi - component signals . we present adaptive gaussian kernel time - frequency distribution according to the feature of cross - components in the ambiguity domain 系統的研究了多分量信號wigner - ville分布中的交叉項，根據交叉項在模糊域的特點，提出了基于信號的自適應高斯核時頻分布。

2 . studies on the wigner - hough transform in the suppression of cross - components , a modified algorithm is present based on adaptive gaussian kernel time - frequency distribution , this algorithm not only suppresses the cross - components but also has good performance in the low snr 研究了wigner - hough變換在抑制交叉項中的應用。通過對wigner - hough變換作一定的改進，提出了基于信號自適應高斯核時頻分布的hough變換。

Time - frequency analysis has got great attention in recent years . as a bilinear time - frequency distribution , wigner - ville distribution , which has the energy representation of signal , has been greatly used in the processing and detection of nonstationary signals 時頻分析是目前國際上非常熱門的一個研究領域，其中具有能量化表示的二次型時頻分布wigner - ville分布被廣泛的應用到非平穩信號處理和檢測中來。

The reason that different distribution frequency of hpi in various e . coli is unclear , either . as the high frequency distribution of hpi in eaggec , this study will focus on the following parts to discuss the function of yersiniae high - pathogenicity island in enteroaggregative e . coli 鑒于hpi在eaggec中的高頻分布，本研究擬從eaggec菌株出發，著重從以下幾個方面對eaggec攜帶的hpi毒力島的功能進行了研究。

Short - time fourier transform and time - frequency distribution series are applied to time - frequency imaging . time - frequency distribution series based on wavelet transform is discussed . , and a new time - frequency tool : frequency - shear distribution is introduced into radar imaging fields 討論了基于小波變換的時頻分布級數，把一種新的時頻分析工具? ?頻率-切變分布應用于時頻成像。

Standard deviation in statistics , a measure of the dispersion of a frequency distribution : it is the average magnitude of deviations from the center of normal curve , calculated by squaring all the deviations , calculating their mean , then finding the square root of the mean 標準偏差：統計中，一種衡量數據組分布的分散或變化情況的數據，是偏離正態分布中間位置數據大小的平均值。

It is proved the effect is good . with 3d figure we can know hrv time - frequency distribution and the information of frequency change with time , while this information can not be gotten only in spectrum region 維格納方法在三維立體圖上展示心率變異信號的時頻分布時，能揭示出隨時間演變頻率演變的信息，而這些信息通過單純的頻域分析是不能得到的。

The climate factor distribution coincide very well with the dust storm occurrence frequency distribution , which suggested that the climate changes induced the dust storm downward trend in whole during these 40 years in china 結果發現氣候因子分布與沙塵暴的發生頻次分布對應性很好，提出氣候變遷導致在這40年中國沙塵暴整體上呈現出下降趨勢。

Calibration typically entails an iterative process that computes coefficients such that the gravity model replicates the trip length frequency distribution and matches base year productions and / or attractions 典型的校準在系數計算中通常有一個迭代過程，好像重力模型復制了出行距離頻數分布，同時匹配基年發生和吸引。