均方譜密度 的英文怎麼說
中文拼音 [jūnfāngpǔmìdù]
均方譜密度
英文
mean squared spectral density- 均 : Ⅰ形容詞(均勻) equal; even Ⅱ副詞(都; 全) without exception; all
- 方 : Ⅰ名詞1 (方形; 方體) square 2 [數學] (乘方) involution; power 3 (方向) direction 4 (方面) ...
- 譜 : Ⅰ名詞[書面語]1 (按類別或系統編成的書或冊子等) table; chart; register 2 (指導練習的格式或圖形)...
- 密 : Ⅰ名詞1 (秘密) secret 2 [紡織] (密度) density 3 (姓氏) a surname Ⅱ形容詞1 (距離近; 空隙小)...
- 度 : 度動詞[書面語] (推測; 估計) surmise; estimate
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And understanding and studying the spectral features and variation rules of geo - targets in the experimental area, raising that it is the basis of geo - targets information collection with imaging spectrometer data to understand spectral features and variation rules of geo - targets, realizing that in a great extent spectral - integrated - form - based classification method can remove the phenomenon of " different spectrum with same objects " resulted from reflection ratio curve translation because of the angle change among sensor, targets and observation direction, and the average and variance images can be introduced to solve the problem of two kinds of geo - target with similar spectral forms and much different values of whole reflection ratio. it is suggested that " red edge " range bands of vegetation, which has close relationship with vegetation cover and biomass, is the main characteristic bands and important basis for careful vegetation classification and quantitative retrieval, and pixel - based derivative spectral analysis is very useful for removing the effects of soil background values and quantitatively retrieving vegetation biomass and cover. the remote sense quantitative retrieval model is developed for main appraisable factors of desertification monitoring assessment with imaging spectrometer data and then the applicability of model is analyzed
研究結果如下:首先針對荒漠化地區的地物特徵,對高光譜數據不同波段的數據質量、波段組合進行了評價,提出了適用於荒漠化監測的基本波段選擇集;初步了解和掌握了研究地區的地物光譜特性及變異規律,進一步明確了掌握地物光譜特徵和變異規律是用成像光譜儀數據提取地物信息的基礎;發現了基於光譜整體形狀的分類方法在很大程度上能夠消除由於傳感器、地物目標觀測方向之間的角度變化引起的反射率曲線整體平移的「同物異譜」現象,對于譜形相似而整體反射率的值相差較大的兩類地物,通過引入均值和方差圖像參與分類得到解決;研究還表明在植被「紅邊」范圍內的波段是進行荒漠化監測的主要特徵波段,這些波段與植被生物量和蓋度都有密切的關系,是開展精細植被分類研究和植被定量反演的重要基礎;像元的導數光譜分析可以消除土壤背景的影響,是進行植被生物量和蓋度定量反演的有力工具;建立了荒漠化監測主要評價因子的定量反演模型,並分析了模型的適用性。The signal process function of the software include these function : digital filter, windowing, auto - correlation function and cross - correlation function, mean and variance, probability density function and probability distribution function statistic ; auto - power spectrum, cross - power spectrum, frequency response function, coherence function, cepstrum analysis based on fft ( fast fourier transfer ) ; joint time - frequency analysis based on stft ( short - time fourier transfer )
軟體的處理功能包括:數字濾波、時域加窗、自相關與互相關處理、均值和方差計算、概率密度和概率分佈函數計算;在快速傅立葉變換( fft )基礎上計算自功率譜、互功率譜、頻率響應函數、相干函數、倒頻譜分析;基於短時傅立葉變換( stft )的聯合時頻分析等。A cyclic radial shearing interferometer was used to diagnose the wavefront distortion of a laser system and an lcslm ( liquid crysnd spatial ligh modulator ) was used to control it. some results have been summarized as follows : l. according to the theory of scalar quanity diffeaction and the model of the random gaussian phase screen of low frequency wavefront, the effect of the low frequency wavefront with different rms gradient on the focal spot of a laser beam was studied
本論文在激光光束波前畸變檢測和控制上進行了新的探索,主要就空間相位調制環路徑向剪切干涉儀以及它對波前畸變的檢測和液晶空間光調制器及其對中頻段波前畸變的控制進行了研究,其研究的內容和取得的成果如下:一、根據標量衍射理論,結合低頻波前畸變的高斯隨機位相分佈模型,研究了不同均方根梯度低頻畸變波前對激光光束焦斑聚焦性的影響,並採用描述中頻段波前畸變的功率譜密度概念,模擬計算了它對激光焦斑旁瓣的貢獻。Prepared technical parameters were optimized by l9 ( 34 ) experiment analysis. a unique method for cleaning and drying of substrate - cleaning used by scour, drying used by infrared light was fished out by large numbers of experiment. chemical mechnism of zno thin film prepared by sol - gel technique was discussed by dta for the first time. by the measurements of sem, xrd and uvs, the thin film was analysed. the result proved that the thin film with strongly preferred orientation of c - axis perpendicular to the substrate surface which surface was homogenous, dense and crackfree was the crystalline phase of hexagonal wurtzite. the thin film was composed of plentiful asteroidal crystal which crystal dimension approximately 10 30nm. the average transmittance of thin film in visible region was above 90 %. the results of measurements else also proved that the thickness of single dip - coating was 75 240nm, this films resistivity was found to be 3. 105 102 3. 96 105 ? cm. the thickness and resistivity of thin film influenced by dope - content, withdrawal speed, pre - heat - treatment, anealing were reseached respectively
利用xrd 、 sem以及uvs光譜儀等分析方法對薄膜進行了研究,結果顯示,所制備的薄膜為六方纖鋅礦型結構,具有高c軸擇優取向性;表面均勻、緻密,薄膜材料由許多星狀晶粒組成,晶粒尺寸大約為10 - 30nm左右;薄膜可見光透過率平均可達90 % ;對薄膜厚度以及電學性能進行了測定后發現:單次鍍膜厚度約為75 - 240nm , al ~ ( 3 + )離子摻雜型氧化鋅薄膜的電阻率在3 . 015 102 - 3 . 96 103 ? cm范圍內;分別研究了摻雜濃度、提拉速度、預燒溫度、退火溫度等工藝參數對薄膜厚度和電阻率的影響。Current. in order to make diffluent piers with low ridge to be popularized and applied, the surface wave of low fr. current is chosen as the research object. we measure the surface wave elements and the velocity distribution of various diffluent piers scheme by the experiment of physical model. we also analyze the average wave height, the the average value of the square of wave, unit width of the wave ' s energy, the probability density distribution of wave height, and the power chart character, so as to reveal the weakening wave mechanism of the diffluent piers
低fr水流的核心是波浪問題,為了低坎分流墩的推廣應用,本研究以低fr水流的表面波浪作為研究對象,通過物理模型試驗,對各種分流墩方案消能工的下游水面波浪要素、流速分佈進行測試,分析低坎分流墩下游波浪的平均波高、均方根、單寬波能、波高概率密度分佈及功率譜特性變化規律,從而揭示了低坎分流墩的削波機理。The mode number and the frequencies range, which were considered during calculating the wind - induced responses of large cantilevered roof by using the method of frequency domain, were analysed and discussed, according to the results of wind tunnel tests of bahamas and guinea stadium grandstand cantilevered roofs, and the rules that rms displacement and rms internal force responses under strong wind force changing with participant modes number and frequencies range were obtained, and which could be explained from the point of wind pressure power spectrum densities of the measured points on surface of the roof
摘要根據援巴哈馬體育場和援幾內亞體育場主看臺懸挑屋蓋風洞試驗數據結果,分析和探討了採用頻域分析法計算大跨度懸挑屋蓋風振響應時應考慮的結構模態數和頻率范圍,得到強風作用下懸挑屋蓋結構均方根位移與內力響應隨參與計算的模態數和頻率范圍的變化規律,並從屋蓋表面測點風壓譜密度的角度解釋了這種變化規律。Mean squared spectral density
均方譜密度The spectral correlation density must be estimated before the ds signal parameter estimation. in order to reduce the effect of random noise, we provide a improved method to estimate the spectral correlation density which is based on the average algorithm. it can make the spectral line be more obvious, and improved the snr limit when estimating these parameters
在利用ds信號譜相關域所表現的特徵進行參數估計時,首先要利用有限時間數據對ds信號進行譜相關密度估計,為降低隨機噪聲對譜相關密度估計的影響,本文引入了集平均的思想,提出採用集平均的方法估計譜相關密度,從而在參數估計時,特徵譜線更顯著,提高了參數估計的信噪比容限。分享友人