頻散量度 的英文怎麼說

中文拼音 [bīnsǎnliángdù]
頻散量度 英文
di ersion measure
  • 頻 : Ⅰ形容詞（次數多） frequent Ⅱ副詞（屢次） frequently; repeatedly Ⅲ名詞1 [物理學] （物體每秒鐘振動...
  • 散 : 散動詞1. （由聚集而分離） break up; disperse 2. （散布） distribute; disseminate; give out 3. （排除） dispel; let out
  • 量 : 量動1. （度量） measure 2. （估量） estimate; size up
  • 度 : 度動詞[書面語] （推測; 估計） surmise; estimate
  • 量度 : [數學] mensuration; measure; measurement; magnitude量度器 measurer
  1. Due to existing signal processing technology ’ s shortage such aslow measurement, narrow measurement range precision and other poor performance, we introduced a high - precise signal processing technology : firstly, to get power spectrum with hanning windowed welch modified periodogram, search its peak value frequency ; secondly, to apply zooming analysis via goertzel algorithm ; at last, to get a highly precise doppler frequency with energy centrobaric rectifying algorithm 。 the simulating result indicated that this technology introduced could get accurate doppler frequency 。 depending on above discussed technology, we designed a signal processing scheme, and developed a signal processing system. the running result showed high performance, verified the feasibility and reliability of the highly precise signal processing technology introduced. in a word, the technology improved ldv ’ s performance such as measurement precision, measurement range, dynamic response time 。 and it will have a wide application foreground

    針對存在的缺點，本文提出了一種應用於激光多普勒測速的高精度信號處理技術，即首先利用加hanning窗的welch修正周期圖演算法得到信號功率譜，搜索其譜峰值頻率，接著利用goertzel頻譜細化演算法對搜索的譜峰進行細化分析，再引入能量重心頻譜校正演算法對細化后的譜峰進行校正分析，從而將離散頻譜分析演算法、頻譜細化演算法和頻譜校正演算法三者有機結合起來，充分發揮各自的優點:通過加hanning窗的welch修正周期圖演算法快速得到功率譜及峰值頻率，通過goertzel演算法獲得分析頻帶的高解析度頻譜，然後通過能量重心校正演算法對細化后的頻譜進行高精度校正，這樣不僅保證了演算法的高效性，而且大大提高了分析的精度。
  2. The key components in laser gyro is he - ne ring laser, and the reciprocal action theory between light and medium is the base in studying the ring laser, use the lamb half classical theory, and on the base of density matrix theory, the optical brounch equation was established, which described the movement of amplifying medium atom in the ring syntonic cavity, and according to the medium polarize theory the self consistent equations was deduced, which describe the light intensity and phasic of the counter - propagating wave. on the basis of this equations, adopted the simulation software matlab and virtual instrument programming language labwindows / cvi, we can do some simulated experiments in study the phenomenas such as amplify and dispersive characteristic of medium, mode pushing effection, burned hole effection and pattern competition, lock - in of frequency and the characteristic of light intensity and phasic of the counter - propagating wave in laser gyro

    激光陀螺的核心部件為he - ne環形激光器，而掌握光與介質的相互作用理論是研究激光器的關鍵，採用拉姆半經典理論為主，在密度矩陣理論的基礎上，推導環形諧振腔中描述he - ne氣體增益介質原子運動的光學布洛赫方程，運用介質極化理論得出描述激光陀螺反向行波的光強、位相所滿足的自洽場方程組，在此基礎上，運用matlab模擬軟體和虛擬儀器編程語言labwindows / cvi ，對激光陀螺中的介質增益色散特性、頻率牽引效應、燒孔效應及模競爭、閉鎖效應及環激光的光強和相位特性進行模擬試驗研究，並且運用全量子理論，對激光工作原理進行分析，得出二能級系統單模輻射場的光子數密度分佈，得出激光場的光子統計分佈，模擬激光場的動態建立過程。
  3. In this paper, high - order accurate weighted essentially non - oscillatory ( weno ) schemes are investigated and their applications in hyperbolic conservation laws are discussed. based on this, a new weno difference scheme which based on dispersion - relation - preserving relation is developed, and representative test cases with this scheme for computational aeroacoustics ( caa ) problems has been implemented and compared in order to test capability of wave capturing ; in addition, weno schemes generally do not converge at high order in the presence of contact discontinuity of euler equations, so a conservative front tracking technique coupling weno schemes and level set method to simulate the translating density profile is presented here, and numerical simulation with this technique for representative test case has been implemented and results show the desired accuracy

    本文研究了高階精度加權基本無振蕩（ weno ）格式及其在雙曲守恆律方程中的應用，在此基礎上作了兩個方面的工作：一是針對高頻聲波問題構造出一種基於保色散關系（ drp ）的weno有限差分格式，並對計算氣動聲學（ caa ）問題的代表性算例進行了大量數值實驗，比較了該格式捕捉波數的能力；另外，針對高階weno格式在處理euler方程的接觸間斷時精度有所降低的問題，研究了利用界面追蹤技術levelset方法和高階激波捕捉weno格式相結合的一種守恆追蹤方法，並且給出有代表性的密度滑移面問題的算例，得到一致高階精度的數值模擬結果。
  4. At present greco is regarded as one of the most valuable methods of radar cross section ( rcs ) computation in the high - frequency region. depending on these conditions, several researches have been completed in this paper : firstly, calculating rcs of complex conducting targets has been accomplished by greco method. the high - frequency rcs of targets are obtained through physical optics ( po ) and incremental length diffraction coefficients ( ildc ) respectively

    本論文做了以下研究工作：首先，實現了運用greco方法計算了高頻區理想導體復雜目標的雷達散射截面（ rcs ） ，分別應用了物理光學法（ po ）和增量長度繞射系數法（ ildc ）計算了目標的面元和棱邊的電磁散射，最後綜合面元與棱邊的散射效應得到目標的總rcs 。
  5. 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。
  6. Chapter 8. the fully distributed optical fiber sensor system on base of raman and rayleigh optical frequency - domain reflectometry to measure microbend and temperature simultaneously is developed

    第八章，研究了基於rayleigh光頻域背向散射和raman光頻域背向散射理論同時測量微彎和溫度分佈的全分散式光纖傳感器系統。
  7. According to the high dispersedness and low precision of measurements when using the traditional time difference method in small diameter and low flow rates conditon, this paper brings forward a new method based on high - speed data acquisition technique. the time difference comes out accurately with high resolving ability of time by using the method and the signal processing algorithms. the developed ultrasonic detection system is composed of two ultrasonic detectors, a transmitting and receiving ultrasonic unit, a high - speed data acquisition unit and a computer

    本文針對傳統的時差法在小管徑、低流速測量時，具有測時結果分散性大、測量精度受計數頻率的影響大等不足，創造性地把高速數據採集技術應用在超聲波流量、壓力測量上，用信號處理演算法求時差，使時差成為一個統計量，有效地克服了超聲波傳統時差法測量精度差、不能測量小管徑、低流速流體流量的缺點，提高了時差測量的解析度和精度。
  8. In this paper, a gray video md - 3d - spiht algorithm is proposed, which extends the md - spiht algorithm into 3d - spiht. this method is to divide the 3 - d wavelet coefficients into some number p of different groups according to their spatial and temporal relationships, and then to encode each group independently using 3d - spiht algorithm, so that p independent embedded 3d - spiht substreams are created. multiple descriptions are created

    2 、將md - spiht方法推廣應用於視頻序列，提出了灰度視頻md - 3d - spiht演算法，該演算法先對一組視頻圖象進行多級離散三維小波變換，在小波域建立空間方向樹，及對空間方向樹分組，再分別對各組進行3d - spiht編碼，即產生多個描述，且每一描述的碼流是完全嵌入式的，易於實現質量可分級編碼。
  9. Two cold - test parameters determine the working voltage, frequency band, efficiency and gain of twt. they are dispersion and interaction impedance of the slow - wave structures ( sws ) in twt, which are very important targets for twt

    行波管慢波結構的色散和耦合阻抗是行波管設計中兩個非常重要的冷參量，它們決定了整支管子的工作電壓、頻帶寬度、工作效率和增益。
  10. The numerical results of the dispersion relation show some nonlinear effects : for a fixed geometry of a waveguid, beam parameters and plasma density, the increment of the modulation parameter may lead to a slight increment of the operating frequency, however, as the modulation parameter increases further, saturation may occur and the dispersion relations are hard to be separated, it is due to the overmodulation of the microwave power, this phenomenon itself belongs to the nonlinear effects

    對於一定的波導、電子注參量和等離子體密度值，等離子體調制系數的增加，使工作頻率略微升高。但是，隨著等離子體調制系數的進一步增加，色散曲線變得彼此之間不可分辨，可以認為是等離子體的過調制導致了柵的飽和。這一現象是非線性的，可見，等離子體柵和調制場中文摘要是非線性關系，等離子體柵是非線性j 。
  11. 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。
  12. Secondly, ground on the duct noise control, the delayed - lms algorithm, which is actulized easily, is brought forward, then the simulation on pc is achieved. it is shown from the computer simulation that for the single frequency noise, there will be a good effect when choosing the suitable parameters ; but for the narrowband noise, the effect will become worse with increasement of the bandwidth. this result is helpful to analyze the parameters influencing anc

    結果表明： （ 1 ）隨著濾波器長度的增大，系統收斂速度變快； （ 2 ）隨著值的增大，系統的收斂速度增大，但是當值超過某一范圍時會引起系統的發散； （ 3 ）次級通路的延遲數與初級噪聲頻率有關； （ 4 ）對于窄帶信號， dlms演算法可以取得一定的降噪量，但是隨著窄帶信號帶寬的增大，降噪效果明顯變差。
  13. According to the raman selection rule and the pl measurement, it is reasonable to evaluate the quality of galnp / algalnp mqw by analyzing the relative intensity ratio of a1p - lo / to. ( 4 ) a new modified random element isodisplacement ( mrei ) model is set up to calculate the dependence between the long - wavelength optical phonon frequencies and the composition of iii - v - type ab1 - xcx mixed crystals. the second neighbor force constants are still assumed to be a linear variation with the composition, but the two first neighbor force constants can be evaluated to be a negative exponent variation with the composition, using the overlapped repulsive potential of the ion crystal combination

    通過實驗我們找到了在這些結構參數上生產gainp algainpmqw的較理想的結果； （ 3 ）首次用喇曼（ raman ）散射方法研究了常溫下的gainp algainp多量子阱結構，除了指認出喇曼光譜中各光學聲子模外，還結合樣品光致發光譜的測量結果，分析發現喇曼光譜中alp - lo to的相對強度比可以在一定程度上評定晶體gainp algainpmqw的生長質量； （ 4 ）在修正的隨機元素等位移? mrei模型的基礎上建立了一個新模型，計算了ab _ （ 1 - x ） c _ x型?族半導體混晶的長波長光學聲子模頻率的組分變化關系。
  14. 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。
  15. Next, the effects of the electron - beam quality on the characteristics of the vircator are investigated with simulation method. the simulation results show that the front edge of the beam pulse has almost no effect on the saturated microwave output, while good front edges can accelerate the saturation of the virtual cathode oscillation, and beam quality ( except its energy spread ) has almost no effect on microwave frequency, and so on

    結果表明：上凸形束脈沖前沿可使虛陰極振蕩器達到飽和振蕩的時間縮短但對微波飽和功率基本無影響；束流脈寬應足夠大，否則虛陰極振蕩器不能達到飽和振蕩（對應本文中的模型，束脈寬應大於16ns ） ；能散度的影響不可忽視，當能散度為5時，束波轉換效率從單能束時的3 . 8降至1 . 5 ；束流質量（除能散度外）對微波頻率基本上沒有影響等。
  16. Rayleigh wave method is a jumped - up and effective in - situ test. we can inverts the velocity structure of the strata through the quantitive interpretation of dispersion curve of rayleigh wave with this method, then distinguish and determine the physico - mechanical properties of the strata by the wave velocity in order to solve the geotechnical problems

    瑞利波法是近年米新興的、行之有效的原位測試方法，該法通過定量解釋實測瑞利波頻散曲線，反演地層速度結構，利用波速區分和確定地層物理力學特性，以解決巖土工程問題。
  17. We give ptr ' s amplitude and phase signal of one dimension based on the theory of ptr, discuss the ptr ' s signal ' s frequency characteristic, and a method for measuring thermal diffusivity of opaque materials is introduced. then, we study on anisotropic materials " thermal conductivity, the temperature field and thermal conductivity tensor of anisotropic materials is theoretically deduced from the theory of ptr, and is proved by the experiment

    從光熱輻射理論出發，推導出一維情況下ptr信號的振幅和位相表達式，討論了光熱信號的頻率特性，介紹了一種用ptr技術測量不透明材料熱擴散系數的優化方法；接著研究分析了各向異性介質受調制激光束輻照下產生的光熱信號，在理論上推導出各向異性介質的溫度場以及熱導率張量並給予一定的實驗驗證。
  18. One is to use fourier transformation to convert the source signal from time domain to frequency domain and to discard high frequency harmonious components upwards of 19 ( gb / t14953 - 93 d5. 3 demanding ), then to have static huffman coding to the quantized char array which is composed of reserved direct current component and basic wave and each high frequency " s amplitudes and angles. the other is to use discrete wavelet transformation to convert the source signal from time domain to frequency domain and to set the high frequency coefficients that its absolute value is smaller than the given threshold to zero, then to have dynamic huffman coding to the quantized char array which is composed of multiple, wavelet ' s level, datum length, low frequency coefficients and reserved high frequency coefficients. mass simulinks and analyses under the two circumstances have done to show that data compression ratio is small and the relative error is also small and within the permission of engineering and the compression problem can be solved in theory of measured datum of power system

    第一種情況的壓縮方法為：採用傳統的傅立葉變換把原始信號從時間域變換到頻率域，舍棄20次及其以上的高次諧波成分（保證了gb / t14953 ? 93d5 . 3要求） ，然後對保留的直流分量、基波和各次諧波的幅值和相角數據量化后和量化時分別乘以的倍數系數構成一個數組，以字元形式保存，採用靜態huffman編碼對變換數據進行壓縮；採用離散小波變換把原始信號從時間域變換到頻率域，然後對分解得到的高頻系數進行閾值量化處理，對乘以的倍數系數、小波變換的階數、小波變換后的低頻、各級高頻以及原始數據長度、量化后的低頻系數以及保留的高頻系數大小、位置構成一個數組，以字元形式保存，採用動態huffman編碼對這個文件進行壓縮。
  19. Some valuable conclusions are summarized by theoretical analysis and simulation experiments : from the side of signal processing, pulse jamming can be deleted by the method of time - domain sliding window accumulation and can be restored by interpolative prediction. ; gauss white nose can be attenuated while jamming disperse point - target by the method of time - frequency analysis in time - frequency domain. ; radio frequency noise jamming can be deleted by the method of average range frequency spectrum and notching in frequency domain

    通過大量的理論分析和模擬實驗，得到了一批具有一定價值的結論：從信號處理的角度出發，對于脈沖式干擾，能夠運用時域滑動窗口積累的方法去掉，並且通過預測插值得到較好的恢復；對于高斯白噪聲干擾，在時頻變換域內應用時頻分析方法可減小其對分散點目標的干擾；對于射頻噪聲，通過平均距離頻頻法和頻域陷波的方法可以去掉；從改變合成孔徑雷達系統角度出發，類似雙基地雷達能夠避免各種干擾，對發射信號進行調幅，調相以及改變調頻斜率都是較好的抗干擾方法。
  20. Since that the choosing line hardware for the neutral ungrounded system has just passed part of the dynamic simulative test, matlab software was chosen to do a lot of simulative tests on single phase - to - grounding fault. and the simulative sampling ratio is almost the same as the hardware ' s. because there is a low wave filter in the hardware, i choose the db15 wave - let to carry out the multidimensional decomposition on the sample by the method of one dimension discrete wavelet in order to obtain low frequency signal including the high frequency transient information on single phase - to - grounding fault

    鑒于實驗室已有的小電流接地系統選線硬體的研製只通過了實驗室里的動模試驗，故選用matlab軟體對小電流接地系統進行大量的單相接地故障模擬試驗，模擬的采樣率和硬體基本一致，由於硬體中帶有低通濾波器，故在進行采樣數據的morlet小波分析時先採用db15小波對采樣進行一維離散小波的多尺度分解，使得分解得到的低頻信號剛好包括了小電流接地系統單相接地故障時的暫態高頻信息，然後對這一信息再繼續進行小波演算法分析，分析結論表明利用變換后的實部、虛部和模值能夠較準確的實現單相接地故障時的故障選線和暫態高頻分量的提取。
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