頻譜因數 的英文怎麼說

中文拼音 [bīnpǔyīnshǔ]
頻譜因數 英文
spectrum factor
  • 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...
  • 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）...
  • 因 : Ⅰ動詞[書面語] （沿襲） follow; carry on Ⅱ介詞1 [書面語] （憑借; 根據） on the basis of; in accord...
  • 數 : 數副詞（屢次） frequently; repeatedly
  • 頻譜 : frequency spectrum; frequency content; spectrum; power density spectrum; power spectrum; [系統] s...
  1. Furthermore, the network technique only support the voice service cannot meet the communication requirements of people. people hope to obtain multimedia service such as packet data, video and picture phone etc besides voice service. all these need operators and researchers to look after the mobile communication scheme which optimizes spectrum efficiency and expands system capacity to accommodate more users in major metropolitan markets

    此外，僅支持語音業務的網路技術已不能滿足人們對信息交流的需求，人們希望能隨時隨地獲取除語音之外的數據、視頻和圖像等多媒體業務，這些因素都促使運營商和研究者尋求頻譜利用率更高、通信容量更大的移動通信解決方案。
  2. In the study of directional spectrum and reflection coefficient of multidirectional wave, firstly the wave elevation trains overlapped by the incident wave and the reflected wave of multidirectional wave are simulated in the method of a frequency corresponding to a direction. then the composed wave trains are analyzed respectively by the mbdm and the mmlm. during the numerical study, the input factors include the various wave parameters, the different measuring wave system and the various reflect characteristic

    在多向不規則波入射波方向譜和反射系數的分析研究中，利用方向頻率對應法模擬了多向不規則波入射波與反射波疊加的波面序列，將此合成波列分別應用mbdm和mmlm進行分析，通過輸入各種波浪參量、不同波浪測量系統和各種反射特性等因子，檢驗了mbdm和mmlm方法的適用條件，對兩種分析方法的性能進行了比較分析。
  3. In the last few hundred meters of the descent, a white - light lamp on the probe will illuminate the surface ? which is normally a muddy red because the atmosphere absorbs the blue frequencies of sunlight ? allowing the disr to do a spectral analysis of the surface composition

    在最後數百公尺的下降過程中，探測器上的白光燈將照亮地表（地表通常為暗紅色，因為大氣吸收太陽光中的藍色頻率） ，讓disr對地表組成進行光譜分析。
  4. Dttb ( digital television terrestrial broadcasting ) is one of the present digital television broadcasting modes, whose transmission media is earth. after a decade of intense research and development, the standards of digital television satellite broadcasting and digital television cable broadcasting have been confirmed. but the standard of digital television terrestrial broadcasting is still in disputation, for its transmission environment is rather awful, its spectrum resource is very limited and its service required is disperse, so it is potential to be improved in many aspects

    數字電視廣播發展近十年來，衛星和有線電纜廣播的基本傳輸體制已確定，而地面廣播由於傳輸環境惡劣，頻譜資源有限，應用需求分散，其標準在各國仍有極大的爭議，因為目前沒有一套標準能解決實際地面傳輸中的所有問題，因此數字電視地面廣播在許多方面都有很大的改進潛力。
  5. This article describes a way of special ultrasonic system which monitors thermal stress in seamless welded rails. this monitoring system is a non destructive testing system, which adopts avr mcu and high - precise time chip processing as the core of it, and adopts the critically refracted longitudinal wave as the object of measuring. my studying focuses on the theory of the monitoring system, which will be listed in this arctile : according to the snell theory, the theory of motivating of critically refracted longitudinal wave is described in details, and the finite element software is used to emulate the propagating course. the formulas of calculating the pts of swr are taken from the acoustoelasticity theory, and the calculating the parameters is introduced. according to assemble materials, three kinds of ways of monitoring the pts of swr using critically refracted longitudinal wave are described, which are measuring the sound - time in changeless distance, ultrasonic critical - angle refractomery and frequency spectrum, the first way of ways is used in this experiment system. the factors, which effect the monitoring system, are assaid in some degree based

    本文的研究工作重點在無縫焊接鋼軌溫度應力測量系統的理論模塊，包括根據snell原理，研究極限折射縱波的激發機理，並使用有限元軟體ansys進行模擬;根據聲彈性理論以及公式推導出計算無縫焊接鋼軌中的溫度應力的公式，並對其中參數的求解方法進行介紹;根據收集的資料，介紹了三種使用極限折射縱波測量無縫焊接鋼軌溫度應力的方法，即固定距離測量聲時法、臨界角折射法和頻譜分析法，本實驗系統使用的是第一種;根據實驗經驗以及相關資料，分析了影響極限折射縱波測量溫度應力的幾個因素，並提出了相應的解決方法;根據實驗系統的需要，獨立設計並加工出相關配套的實驗設備，包括實驗鋼塊、有機玻璃楔塊、固定件、載荷外框裝置等。
  6. In addition, the author puts forward that the eggs could be recognized based on the difference in the frequencies of their prompted sounds. because the eggs " prompted sounds are lied on low frequency bands, the microphone and sound amplifier that have excellent duration response should be used. the output signal from the sound amplifier is transferred to data signal by a / d card before it is put into computer

    蛋品激勵出的聲音主要集中在低頻段，因此選擇在低頻段有好的頻率響應特性的麥克風和放大電路；放大輸出信號通過a / d採集板變換成相應的電壓數值信號送入計算機，對離散的信號數據進行傅立葉變換得到它的頻譜圖和各頻段能量分布圖；而後將能量分佈特徵數據作為神經網路的輸入值，這樣，好蛋和破損蛋的模型就建立起來。
  7. 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。
  8. Finally, the headwaters of harmonic current and its harms to power system are discussed, the influences of harmonic currents to short - circuit verifying are analyzed, some parameters are gained according to the analyse on vibration spectrum of the electrodynamic stress

    最後，討論了電力系統諧波的產生原因及其危害，分析了電力諧波對短路動穩定校驗的影響，通過對含有諧波的短路電動力的頻譜分析，得到相應的動穩定校驗參數。
  9. From the experimental results, we studied the relationship between the diameter of fiber, the composition of s s and the impacts upon the electromagnetic parameter of fibers. get following conclusions : both the complex permeability and the complex permittivity of ss fibers decreased with the increase of diameter in some region, the complex permittivity of 304 ss fibers, 2 m in diameter, could be up to 2. 5 at the 2 ghz, the 302 ss fibers had better frequency dispersion properties than others, agreed with the requirements of the wide - band radar absorbing material in the range of 2ghz ~ 12ghz

    西安建築科技大學碩士學位論文討論了影響不銀矜岡纖維電磁參數的幾個因素，實驗結果出發研究了纖維直徑、成分對纖維電磁參數的影響，得到以下結論:不鉀練岡纖維的微波磁導率隨纖維直徑的減小而增大; 2微米的304不銹鋼纖維的復數磁導率p 』 『在zgi ]吃處達到2 . 5 ; 302不韌矜岡纖維電磁勝能明顯優于其它兩種，且頻譜特性在2 ~ 1zghz范圍內符合對吸收劑頻譜特性的要求。
  10. Secondly, basing on the theory of on - off gain of small signal, the raman gain coefficient for frequency shift between 0. 5 and 20 thz of standard sigle mode optical fiber is measured by pump - probe method through a super luminescent diode ( sld ) as a broadband small signal probe source. thirdly, numerical simulation analysis of gain characteristic of raman fiber amplifier for c band wdm signal light is made according to the raman gain coefficient of the fiber measured before through target and four rank runge - kutta method. at the invariability of wavelength and maximum power of each of two pumps, schematic of powers of two pumps for best flatness on c band wdm optical gain was found out, at the same time, the factors of resulting in gain saturation is analyzed, too

    本文首先應用經典的電磁理論對拉曼光纖放大器的工作機制進行了分析，然後，根據小信號理論推導出的開關增益求出了光纖拉曼增益系數的表達式，採用泵浦-探測波的方法，利用超輻射激光二極體（ superluminescentdiode簡稱sld ）作為探測光源，測量了所用標準單模光纖頻移為0 . 5 - 20thz的拉曼增益系數，之後根據所測得的光纖的拉曼增益系數譜對應用該類光纖構成的放大c波段wdm光信號的拉曼光纖放大器的增益特性採用打靶法和四階龍格- - -庫塔進行了數值計算，在給定了兩個泵浦光源的波長和最大功率后，找出了反向泵浦情況下使c波段wdm光源增益最平坦的兩個泵浦的各自最佳功率，同時也分析了導致信號光飽和的原因。
  11. We have taken the policy decision that, subject only to physical constraints like spectrum limitation, there should not be a ceiling on the number of licences to be issued

    我們已作出政策決定，除非受實際因素如頻譜所限，電視牌照的數目不應設有任何上限。
  12. Subject to spectrum or other physical constraints, there should not be a ceiling on the number of licences to be issued for television programme services carried on dtt multiplexes ( paragraph 6. 9 )

    基於頻譜或其他實質因素的限制，以數碼頻道傳送的電視節目服務，不應為發牌數目設上限。 （第6 . 9段） 。
  13. By studying the discrete fourier transform properties of the band - limited digital signal, the authors introduce alternating projection neural networks into the paper, expand apnn ' s application scope from real field to complex field, and present several important conclusions on apnn. analyzing and discussing network ' s tolerance to noise, convergence rate and the spectral leakage problem of the truncated signal expected to be extrapolated by using these conclusions, the paper presents an extrapolation algorithm for band - limited signals based on alternating projection neural networks. a lot of simulation experiments show that the algorithm is effective. in addition, the algorithm is also effective to spectrum extrapolation. owing to adopting network structure, the algorithm is prone to parallel computation and vlsi design, and consequently can satisfy real time military processing needs

    本文通過對頻帶受限數字信號的離散傅立葉變換特性的研究，引進了交替投影神經網路，並將其應用范圍從實數域拓廣到復數域，且給出了在復數域仍然成立的若干結論.運用這些結論，在對網路噪聲抑制、網路收斂速度及待外推信號因截斷而造成頻譜嚴重外泄問題的分析與討論的基礎上，提出了一種基於交替投影神經網路的外推演算法.模擬實驗表明該方法是行之有效的.另外，該演算法對頻譜外推同樣適用；由於它採用全互連神經網路結構，易於并行計算和vlsi實現，從而可滿足軍事上實時處理的需要
  14. We revised frequency spectrum functions by using weighting factor - the distance between direct component and alternating component, and improved the acuity of focus measure curve

    提出用交流分量到直流分量的距離作為加權因子對頻譜評價函數進行改進，有效地提高了對焦評價曲線的靈敏度。
  15. In large rotating machinery using filmatic bearing ( turbogenerator, air compressor, etc. ) there is a potential trouble from impefect installation or running conditions, a metals " contact between rotors and shells. the trouble is usully called rubbing. the advantage of ae technologe in the rubbing diagnosis and early detection is showed. instead of classical ae characteristic parameters ( counts, amplitude, energy, duration and the other ones ) a new feature extraction by frequency analysis of ae envelop signals is discussed. both research of ae process and field experements indicate that periodic components in the envelop spectrum related to rotational speed increase evidently at the beginning of rubbing production, hence are highly sensitive to the rubbing fault diagnosis. according to the new design an acoustic emission equipment for the rubbing diagnosis named buaa ae testing system is developed and described

    汽輪發電機、空氣壓縮機等採用油膜支撐的大型轉動機械，由於安裝或運行中的原因，在轉子旋轉過程中，可能和器壁發生輕微的摩擦和碰擊，簡稱碰摩.聲發射技術在碰摩發生特別是故障早期診斷上有優越性.本系統的特點是沒有沿用傳統的計數、幅度、能量和持續時間等聲發射特性參數，而是在聲發射包絡信號的頻率分析中進行特徵提取.聲發射發生的過程分析和現場試驗都表明這種方法對碰摩檢測很敏感，在碰摩發生的起始階段，包絡譜中與轉速同步的周期性分量顯著增加.根據這種新的設計思想自行研製了buaa碰摩聲發射檢測儀並對此作了介紹
  16. In the code division multiple access ( cdma ) system, the multiple access interference ( mai ) mitigation capability as well as system capacity are determined, to a great extent, by the correlation properties of spreading sequences ; while adaptive modulation and coding ( amc ) with high spectral efficiency is the key technique to obtain high speed and low symbol error rate ( ser ) performance in mobile data transmission

    在碼分多址（ cdma ）系統中，擴頻序列的特性在很大程度上決定了抗多址干擾（ mai ）能力和系統容量，而高頻譜效率的自適應調制編碼（ amc ）技術則是獲得高速率和低誤碼率（ ser ）移動數據傳輸性能的關鍵因素。
  17. Multicarrier wireless communications have been widely investigated in the past decades. recently, two - dimensional spread spectrum ( 2d - ss ) system has drawn a lot of attention because of its full utilization of spreading characteristics in the frequency domain and time domain. compared with multicarrier code division multiplex access ( mc - cdma ), 2d - ss system can effectively mitigate multiple access interference ( mai ) due to spreading in the time domain

    當前多載波無線通信技術得到了廣泛的研究，二維擴頻通信系統是近年來提出的新的擴頻通信方式，由於二維擴頻系統從時域和頻域上分別對數據信號進行頻譜擴展，因此它同時具有時域擴頻和頻率擴頻通信系統的特點，是對傳統的一維時域直接序列擴頻和多載波擴頻的推廣。
  18. On the basis of previous work, we developed a new data processing system by use of dsp & oop. the new system overcame the problems existed in the old data processing system successfully, such as the bug which cause program dead loop when the data is too long, and the frequency leak due to principle limit of fft filter. in addition, we eliminated the measurement error brought on by phase warp

    我們在前人的工作基礎上，利用現代數字信號處理技術和面向對象的軟體開發技術，統一了彈上黑匣子數據處理系統的操作平臺，完善了轉速、掃描角測試數據處理系統，修正了原有處理程序中的因數據長度過長而導致程序死鎖的bug ；利用有限沖擊響應（ fir ）濾波器，在濾去噪聲的同時，有效地解決了矩形窗fft濾波的頻譜泄漏問題；另外還解決了因相位偏差而導致的測試誤差。
  19. Combining the hardware and software, the real - time performance is also discussed. ( 5 ) when the system is debugged, some problems are discussed in detail and solved, such as volts d. c of the input signal caused by a / d converter and aliasing in frequency spectrum arising as re - sampling input data. experimental results show that the performance of the system is satisfactory

    （ 5 ）討論了本dsp系統的軟、硬體調試方法，並詳細地討論了在系統總體調試時，出現的各種問題? ?如a d器件引起的輸入模擬信號的直流偏置、波束形成過程中由於數據抽取引起的頻譜混疊，解釋和說明各種問題出現的原因，並提出了相應的解決方案。
  20. Secondly, this paper details the basic theory of fourier transform, and the problems which must be paid attention to in the practical application. the reasons of the error caused by the traditional electric signal detection methods based on the windowed dft are thoroughly analyzed. besides, many cosine windows are introduced

    其次對傅立葉變換的基本理論、基本形式以及實際應用中應注意的問題進行了詳細的闡述，對傳統的基於加窗dft的諧波檢測方法的誤差原因及減少誤差的方法進行了分析，並介紹了各種不同的餘弦窗函數，進而簡要分析了幾種常見的頻譜校正方法。
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