正弦時間函數 的英文怎麼說

中文拼音 [zhēngxiánshíjiānhánshǔ]
正弦時間函數 英文
sinusoidal time function
  • 正 : 正名詞（正月） the first month of the lunar year; the first moon
  • 時 : shí］Ⅰ名1 （比較長的一段時間）time; times; days:當時at that time; in those days; 古時 ancient tim...
  • 間 : 間Ⅰ名詞1 （中間） between; among 2 （一定的空間或時間里） with a definite time or space 3 （一間...
  • 函 : 名詞1. [書面語] （匣; 封套） case; envelope 2. （信件） letter 3. （姓氏） a surname
  • 數 : 數副詞（屢次） frequently; repeatedly
  • 時間 : time; hour; 北京時間十九點整19 hours beijing time; 上課時間school hours; 時間與空間 time and spac...
  • 函數 : [數學] function函數計算機 function computer; 函數計算器 function calculator; 函數運算 functional operation
  1. There are five parts are as follows : in part one, the concept of switching function is introduced first to establish the nonlinear mathematical model of the induction motor variable frequency speed adjustment system which is fed by a sine pulse width modulated ( spwm ) inverter and takes the effect of the main magnetic circuit saturation into consideration, then the low frequency oscillation of the system is simulated according to the model. next, from the view point of energy conversion of the inverter - induction system, a criterion for the low frequency oscillation is proposed to determine whether the system is in low frequency oscillation which is judged by whether the interval of the negative current component of the inverter input current is more than 1 / fc ( fc is the carrier wave frequency of the inverter ) or not

    首先引入開關函數概念，建立了正弦脈寬調制（ spwm ）逆變器供電異步電動機，考慮主磁路飽和時的變頻調速系統整體數學模型，模擬系統的低頻振蕩；其次從逆變器-異步電動機系統能量轉換角度出發，提出通過檢測逆變器輸入電流中負電流的間隔時間是否大於1 / f _ c （ f _ c為逆變器載波頻率）來判定系統是否出現低頻振蕩；最後的實驗結果驗證了系統低頻振蕩建模和判據的實用性和正確性。
  2. Lacking of space locality in time domain, fourier analysis can only make certain of the integral singularity of a function or signal. as a result ; it is difficult to detect the spatial position and distribution of broken signal by fourier analysis. wavelet analysis has the characteristic of spatial locality, and its wideness in both windows of the time and the frequency can be adjusted, so it can analyze the details of a signal

    小波分析優于傅里葉之處在於，小波分析在時域和頻域同時具有良好的局部化性質，因為小波函數是緊支集，而三角正、餘弦的區間是無窮區間，所以小波變換可以對高頻成分採用逐漸精細的時域或空間域取代步長，從而可以聚焦到對象的任意細節。
  3. In this paper, according to the periodically active characteristics shown in the historical earthquake data in this region since 1900, we describe the rule of seismicity with sine function and furthermore make a preliminary forecast of the seismicity intensity and the developing trend in northeast china till the year of 2008 by using the periodogram of time sequence and other analytical methods

    摘要根據東北地區1900年以來的歷史地震資料所顯示的周期性活動特點，用正弦函數描述其地震活動規律，並結合時間序列的周期圖及其他一些地震活動性分析方法，對該地區未來1 ~ 3年地震活動發展趨勢和地震強度作了初步預測。
  4. The classical signal analysis method is fourier transformation, whose essence is to decompose the signal wave into many sine waves, and which also can be seen as representation of time function in frequency domain

    傅里葉（ fourier ）變換是經典的信號分析方法，其實質是：把波形分解成許多不同頻率的正弦波之和，可看作是時間函數在頻率域上的表示。
  5. The thesis mainly deals with the third part of across : " sompi " cepstrum methods. the principle and system structure of across a re first introduced. the propagation of wave in media is simply studied and its transfer function in frequency domain is modeled as superimposed damped exponential sinusoids, each damped exponential sinusoid is called as a wave element and its exponential index part consists of two factors : group velocity travel time and decayed factor

    為此，首先介紹了across的原理與組成和通過簡單地討論地震波在介質中的傳播情況建立起介質的傳遞函數模型，指出：在一個狹窄的頻率窗口裡，介質的傳遞函數可以用有限個阻尼正弦項的疊加的形式表示，每個阻尼正弦項代表一個波成分，其指數部分包括兩個因子：波成分在介質中的傳播時間和衰減因子。
  6. The accurately controlled signal source generates sinusoidal elastic wave accurately controlled in frequency and stable in phase to " illustrate " underground media. time signal stacker receive signal by stacking and doing fft to measure the transfer function of media. " sompi " cepstrum method retrieve group velocity travel times and decayed factors of wave element from observational data of transfer function in a limited frequency window

    精密可控震源用於產生頻率精確相位穩定的正弦彈性波以照射地層內部，信號疊加器通過對接收信號進行疊加和進行傅立葉變換的方式實現對介質傳遞函數的精密測量， 「存否」倒譜方法能夠根據一段窄帶頻域傳遞函數數據獲得時域上各個波成分的群速度傳播時間和介質衰減因子。
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