頻率反演 的英文怎麼說
中文拼音 [bīnlǜfǎnyǎn]
頻率反演
英文
frequency inversion-
2, under equally see the quantity, compress the calculate way s exportation code plain deal connect the good and bad that decide its function of the good and bad, or say, output the code the term of same alike rate the bottom, and the portrait quantity reflected the function of the compression calculate way. adopt with dv all because of the m - jpeg an inside compress the way, efficiency of their compression certainly want lower than mpeg2. certainly, this is an average circumstance, at the time that low code rate, the mpeg2 can compare the m - jpeg compression the ratio high and a lot of but keep the good diagram to resemble the quantity ; but at request the diagram to resemble the quantity the good time for example the sow the room program edit with empress period creation, their difference to is not very big. too is to say, just at the compression efficiency that not emphasize the portrait quantity that the circumstance, mpeg2 is high
2在同樣的視頻質量下，壓縮演算法的輸出碼率直接決定其性能的優劣，或者說，輸出碼率相同的條件下，圖象質量的優劣反映了壓縮演算法的性能。由於m - jpeg和dv都是採用幀內壓縮方式，它們的壓縮效率當然要比mpeg2低。當然，這是一個平均情況，在低碼率的時候， mpeg2可以比m - jpeg的壓縮比高很多而保持較好的圖像質量而在要求圖像質量很好的時候比如演播室節目編輯和後期製作，它們的差別不是很大。It has been shown that : with the increase of the kerr medium intensity parameter u, the rabi oscillation extent of the mean photon number decrease and the rabi oscillation frequency becomes rapid, the antibunching effect becomes strengthened ; with the increase of n, the interaction between the field and atoms gradually becomes weak, however, the interaction between the field and the kerr medium gradually becomes strengthened and happen in advance ; with the increase of the coupling constants of two atoms, the rabi oscillation extent of the mean photon number decrease and the rabi oscillation frequency becomes rapid too, the antibunching effect becomes weak
結果表明：隨著值的增加，光子統計演化曲線的rabi振蕩的幅度減小，振蕩頻率變快，系統的反聚束效應增強；隨著初始場強（ ? ）的增大，場與原子的相互作用逐漸減弱，而與介質的相互作用逐漸加強並提前發生。隨著原子間耦合系數g的增大，光子統計演化曲線的rabi振蕩的幅度減小且振蕩周期縮短，同時，系統的反聚束效應減弱。It has been shown that : the little indentation which represents the quantum noise of the system appears in the evolution curves ; the quantum noise which is caused by virtual photon field gradually becomes weak when w increases, the quantum noise increases when n increases ; the virtual photon process make the antibunching effect strengthen, make the squeezing degree deepen obviously, and lead to the additional vibration of entropy, the oscillation extent of the additional vibration of entropy increases when n increases and decreases when co or g increase. besides, the quantum dynamics of two coupling atoms interacting with a single mode ligh t field in a kerr medium is studied in this paper ; the influences of the kerr effect on the mean photon number, the degree of second order coherence of field, the evolution of the field entropy and the squeezing effect are also discussed
）的增大，量子噪聲分別減小和增大；虛光子過程使光場的反聚束效應增強，使光場的壓縮程度明顯加深，並引起了附加的「熵振蕩」 ，這種附加「熵振蕩」的幅度將隨著光場初始平均光子數（ ? ）的增加而增大，隨著光場頻率和原子間耦合系數g的增大而減小。本文還研究了充滿kerr介質腔中「耦合雙原子-單模光場」相互作用系統的量子動力學性質，研究了克爾效應對場的平均光子數、二階相干度、場熵演化特性及光場壓縮效應的影響。Severe fires can often cause changes in successional rates and soil hydrologic functions, degradation of soil physical properties, alter c : n ratios, and result in subsequent nutrient loss through accelerated erosion, leaching or denitrification, and alterations in microbial populations and associated process can occur
高強度火燒往往能引起演替頻率的改變，土壤物理性質退化，水文功能發生改變，改變c n比，加劇侵蝕、淋溶和反硝化作用，導致養分流火，微生物數量及其相關過程發生變化。There is difference frequency measurement requirement for every part of pid regulating, difference between dynamic quality and static quality in response time and accuracy. according to these, it use the interrupt functions and high - speed counter of the simens s7 - 200 plc cpu226 basic unit and some peripheral circuit to measure frequency ; in software designed, the procedure frame of hydraulic - turbine governor and disperse process of parallel pid are analyzed, an improved pid algorithm is adopted to realize a pid regulation mode with variable structure and parameters ; the mechanical liquid - pressure system of the hydraulic - turbine governor is with electric - hydraulic converter unit of step motor. according to the drive character of five phase of response step motor, a variable frequency regulated voltage driver unit is designed in order to realize interface between plc and driver of step motor
本文利用s7 - 200plc自身的特點設計了頻率測量單元，根據pid調節各個環節的特點，以及調速器動態特性、靜態特性對頻率測量的實時性和精度要求的不同，利用s7 - 200plc基本單元中內置的高速計數器以及相應的外圍放大整形、分頻電路，實現了水輪發電機組頻率的測量；在軟體上，對微機調速器的整個程序框架、並聯pid的離散化過程進行了分析，選用改進的pid演算法實現了變參數、變結構的pid調節模式；調速器的機械液壓隨動系統具有步進電機電液轉換元件，採用五相反應式步進電機，根據其驅動特性設計了變頻調壓驅動器，實現plc與步進電機驅動器之間數字介面。Then, we establish the finite element analysis models of the antenna in different structure layout, and obtain the corresponding frequencies and model shapes. finally, according to the importance of each object, we set up the model of multiple objects that aims to maximize the first natural frequency and minimize the mass. combining orthogonal experiment and variant weighting coefficient method, we formed an effective multiple objects optimized algorithm basing on the neural network and genetic algorithm
本文首先詳細的敘述了天線結構的各組成單元，闡明了天線反射拋物面的形成原理；然後在ansys軟體環境中建立了不同結構布局下天線的有限元分析模型，分析計算了各種情況下天線的的固有頻率與振型；最後依據天線各指標的重要性，建立了以一階固有頻率最大、質量最小為目標的天線結構多目標優化設計模型，並基於神經網路和遺傳演算法，結合正交實驗和變加權系數技術，形成了一種有效的多目標優化演算法，在matlab平臺下實現了天線的結構多目標優化設計計算程序，求得了天線的最佳結構參數。According to the numbers of segmentations, dts has multi scale feature and can reflect different trend similarity of time series under various analyzing frequency. 2 ) an enhanced algorithm, based on dual threshold value, and the conception of sub - series linear are proposed. relative point average error is used to measure the linear degree of sub series, which produced by bottom _ up algorithm
對應時間序列線性分段數目的不同，序列趨勢距離具有基於時間的多尺度分析特性，可以有效反應不同分析頻率下時間序列的相似程度； 2 ）採用相對點平均殘差衡量bottom _ up演算法劃分的子序列線性度，提齣子序列線性度概念和一種雙誤差閥值改進演算法，大大提高了趨勢序列模型的準確性。The paper proposes a feedback pre - equalization ( f - pe ) method based on channel estimation in a frequency - selective rayleigh fading channel
在頻率選擇性瑞利衰落通道條件下，提出一種基於通道估計的反饋?預補償均衡檢測演算法。In this paper, we study inversionless lasing of frequency up - conversion in an open v - type system with incoherent pump. making theoretical analysis and numerical calculation by density - matrix equations of motion, we derive the conditions for the onset of lwi and discuss the effects of the parameters of the system, the detuning of driving field and probe field on the gain, and discuss nonlinear effect in the frequency up - conversion regime. we also give stability and transient analysis
本論文研究了具有非相干泵浦的開放v型系統頻率上轉換無粒子數反轉激光，利用密度矩陣運動方程，通過理論分析和數值計算，得出該系統產生無粒子數反轉激光的條件，討論系統各參數的變化和驅動場與探測場的失諧對激光增益、色散和粒子數差的影響，還討論了頻率上轉換區域的非線性效應，分析了增益的穩定性及系統的瞬態演化過程。The following algorithms have been proposed and tested in the thesis : 1 frequency selective fading : combine the isomorphism between the input space and the output space and propose a new approach to blind equalization of the channel. compared with conventional methods, the new approach offers lower computational complexity, better performance, and more robust against the over - determination of the system order ; 2 time selective fading : a new approach to the equalization of time selective channel based on the zero - forced equalizer is proposed which is more simple in its structure of algorithm ; 3 time - varying channel : using the instantaneous mean value changes of the output signal to extract the information of channel variations and model it using ar model, kalman filter is then employed to track channel variations, it bears faster ability in tracking the variation of tv channels ; based on the isomorphism between the inputs and the outputs and some of the approaches using in mimo system, a new algorithm of equalization of simo time - varying channel is proposed, which also share the merits of being robust against the over - determination of the system order ; model the time - varying channel using the multi - resolution decomposition wavelets, and then a blind identification method based " on the model is proposed ; at last, a new model for equalization and identification of mimo system is proposed
主要工作在以下幾個方面： 1 、針對頻率選擇性衰落通道：結合輸入輸出空間同構關系提出一種新的頻率選擇性通道均衡方法，與傳統方法相比，該方法計算量更小，收斂速度更快，性能更優，且對系統階次的過確定表現穩健，具有實際均衡應用價值； 2 、針對時間選擇性衰落通道：提出一種基於迫零均衡的時間選擇性通道均衡方法，演算法結構簡單； 3 、針對時變色散通道：利用瞬態均值曲線提取通道時變信息，對之ar建模，利用卡爾曼濾波器跟蹤時變通道抽頭變化，可以快速跟蹤通道變化；基於輸入輸出空間之間的同構關系以及多輸入多輸出系統的處理方法，提出了新的單輸入多輸出色散時變通道均衡與識別演算法，同樣具有對通道階次過確定保持穩健的優點；結合小波多解析度分析提出一種基於小波模型的通道盲識別演算法；研究時變的多輸入多輸出系統的盲均衡與盲反卷積問題，給出一種時變系統處理模型。2 ) radar incidence angle and surface roughness correction : to make radar incidence correction and eliminate the surface roughness effects, a wide range of surface parameters ( soil moisture, surface rms height, correlation length, incidence angle ) was input to the ibm model to simulate the effect of surface roughness and radar incidence angle on the sensitivity of soil moisture to the radar backscattering coefficient. a simple model was established to simulate the effects of incidence angle and surface roughness. 3 ) establishment of soil moisture change inversion model : according to a modified ibm model simulation results, the bare surface backscattering coefficients can be expressed as a funtion of the dielectric component for a given surface roughness when the surface slope greater than 2. 0, which is valid for most nature surface : in above equation, r0 is the surface reflectivity at normal incidence
本研究中，首先利用基於微波輻射傳輸方程的微波植被模型和積分方程（ iem ）模型模擬了各種地表土壤水分含量情況下，植被覆蓋、地表粗糙度（包括地表均方根高度和相關長度） 、雷達入射角對c波段（頻率4 . 7ghz ）水平極化（ hh ）雷達後向散射系數的影響，在此基礎上，建立模型消除了植被覆蓋、地表粗糙度、及雷達入射角對雷達後向散射的影響，利用多時相50m解析度radarsatscansar雷達後向散射系數圖像反演得到了地表土壤水分變化模式信息。The second part brings forward a new ar - model - based arm detection method based on features of arm and characteristics of velocity and acceleration of the radar echoes. by establishing two - order ar models, this new detection method computes the poles of models representing different targets, thus estimates the acceleration of the targets so as to determine the nature of the targets. furthermore, this method can not only be applied when the arm is being tracked by radar, but also be put into use in radar ’ s seeking and scanning times
第二部分則是根據反輻射導彈（ arm ）的特點及其雷達回波信號中速度、加速度等特徵，提出了一種新的基於ar模型的arm檢測演算法，該方法通過建立二階ar模型、估計代表不同目標的模型極點，並由此估算目標加速度來判斷目標性質，該方法不僅可以在雷達已跟蹤上arm后採用，而且適用於雷達搜索掃描時使用，模擬結果表明該方法具有解析度高，對雷達脈沖重復頻率（ pulserepetitionfrequency ， prf ）及積累脈沖數要求不高的特點，在低的prf及少的積累脈沖下，利用該方法仍可有效地識別檢測arm 。In this paper, consulting the idea of software radio and using the three important theories of maximum mean power estimate ( mmpe ) for symbol synchronization algorithm, the kalman decision - feedback equalization ( dfe ) algorithm and the decision - feedback phase lock loop ( dfpll ) algorithm, a kind of low frequency digital demodulate scheme over high - frequency ( hf ) radio channels for 8psk signial is realized
本文利用軟體無線電的思想，提出了一種hf通道8psk信號低頻采樣數字化解調方案。討論了實現該方案的三個核心演算法：最大平均功率定時同步演算法、判決反饋式鎖相環和卡爾曼均衡器，分析它們的基本理論，並進行了性能測試。From theoretical analysis, we know the existing demodulation methods have limitations as following : one is that the subtraction of the two signals frequencies will display as the result of demodulation when we demodulate two time - domain adding signals without modulating information ( fault information ) ; the other one is that aliasing phenomenon will occur as a result of getting absolute value, detection or square in the process of generalized demodulation analysis, such phenomenon will result in some superfluous frequency composition on the frequency spectrum, which will puzzle the detec tion of mechanical vibration. if the sampling frequency is selected from a suitable range, the aliasing phenomenon will be avoided ; the last one is that aliasing frequencies will be produced in zoom demodulation analysis because this algorithm cannot employ digital low - pass filtering to avert the folding frequencies of higher harmonics in the process of zoom sub - sampling
現有的解調分析方法存在以下三種局限性：將不包括調制信息（故障信息）的兩時域相加信號，也以其頻率之差作為解調信號而解出；廣義檢波濾波解調分析中，由於取絕對值、檢波或平方過程可能產生混頻效應，在解調譜中表現為無法分析的頻率成分，並由此推導出避免這種混頻現象的采樣頻率的選取范圍，從根本上避免此類誤診斷的產生；幾種細化解調分析新演算法中，因為無法在細化分析的選抽時進行數字低通濾波，有可能會出現調制頻率的高次諧波成分發生頻率混疊而反折到低頻部分的現象。Because the synthetic seismic record and the seismic record data got in the surface are not well matching caused by the dispersion of seismic wave, frequent correction between them must be done before use. under control of well logging data, there are two important methods to get wave impedance from seismic data inversion : wave impedance inversion method based on convolution model and wave impedance inversion method based on wave equation. using seismic data attributes can predict the information of logs
測井資料和地震資料是地震勘探中兩種最重要的資料，由於地震波的頻散，使合成地震記錄與地面地震記錄不能完全匹配，因此使用之前必須對二者進行頻率校正地震資料在測井資料約束下可以進行反演，以求取地下波阻抗，主要有兩種方法：基於褶積模型的波阻抗反演方法和基於波動方程的波阻抗反演方法可以用多屬性變換由地震資料預測測井信息。Synthetic aperture radiometer applies the interferometric principle to sample in the spatial frequency domain and retrieves the image by fourier or other numerical transformation
綜合孔徑輻射計利用孔徑綜合原理在空間頻率域中采樣，通過傅立葉變換或其他數學變換獲取反演亮溫圖像。Comparison study between the constant modulus decision feedback equalizer ( dfe ) and several others is made on combating the frequency selective fading of uwac, and their tracking performance to time varying is also investigated
?針對水聲通道的頻率選擇性衰落，對比研究了常數模判決反饋盲均衡演算法與其它幾種盲均衡演算法的性能。針對水聲通道的時變特性，研究了該演算法的跟蹤摘要性能。First, vm - agr algorithm and variance - correcting method are proposed to greatly improve the performance of original agr algorithm
提出了可變縮率的agr演算法和方差頻域反饋修正法，有效改善了原agr演算法的綜合性能。The study state of art and development trend of structural damage identification research is simply summarized in this paper. hilbert - huang transform ( hht ) is applied to the damage identification and intrinsic frequency confirmation of time - variable structures. furthermore, a kind of inverse calculation is presented to calculate structural stiffness. this method can solve three main problems : the time that damage occurred, the location and the degree of damage
本文簡要總結了結構損傷識別領域的研究現狀和趨勢，圍繞損傷引起固有頻率變化這個特徵，將希爾伯特?黃變換（ hht ）應用於時變結構的損傷識別和損傷前後固有頻率確定上，並結合牛頓迭代法，對結構剛度進行反演計算，從而解決結構損傷識別領域所關注的三個主要問題:損傷發生時間、損傷位置以及損傷的程度。The inversion ' s resolution is restricted by seismic sampling rate, dominant frequency and bandwidth used a practical model to prove, and two difference concepts are put forward between seismic resolution and stratigraphic resolution
用實際模型論證反演的解析度與地震資料解析度的關系，認為反演的解析度受地震資料的采樣率、主頻和有效頻帶的限制，並提出地震分辨和地層分辨兩個不同的概念。分享友人