空間頻率譜 的英文怎麼說

中文拼音 [kōngjiānbīnlǜpǔ]
空間頻率譜 英文
spatial frequency spectrum
  • 空 : 空Ⅰ形容詞（不包含什麼; 裏面沒有東西或沒有內容; 不切實際的） empty; hollow; void Ⅱ名詞1 （天空） s...
  • 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...
  • 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...
  • 率 : 率名詞（比值） rate; ratio; proportion
  • 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）...
  • 空間 : space; enclosure; room; blank; interspace
  • 頻率 : frequency; rate
  1. Based on the propagation law of the cross - spectral density function in the space - frequency domain, the properties of polychromatic vector gsm beams through a paraxial optical abcd system are studied. the analytical propagation expressions for the cross - spectral density matrix of vector gsm beams passing through a paraxial optical abcd system are derived, which permits us to study the propagation properties of vector gsm beams, including the propagation - induced polarization changes, effect of the spectrum bandwidth and irradiance distributions in a unique way. there are some applications of the theoretical results

    基於空間一頻率域中交叉譜密度函數的傳輸理論，研究了多色矢量gsm光束通過abcd光學系統傳輸時偏振特性的變化規律，首次推出了矢量高斯一謝爾模刑fgsm ）光束通過近軸abcd光學系統交叉譜密度矩陣的傳輸公式，並對矢量gsm光束傳輸中偏振的變化、譜寬的影響和強度的分佈等進行了統一研究。
  2. 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。
  3. The results show that, as for the single - mode transmission, the dispersion relations yet include space - dispersion ( k dispersion ) which relates to angular spectrum of fields of in - waveguide, in addition to the material - dispersion and the waveguide - dispersion

    分析結果表明：對于單模傳輸，色散關系中除了與頻率有關的材料色散和波導色散外，還應包括與輸入端光場的角譜有關的空間色散（ k色散） 。
  4. Growing demand for greater wireless data capacity and the crowding of regulated radio - frequency spectra favor systems that offer not only high bit rates but high bit rates concentrated in smaller physical areas, a metric that has come to be called spatial capacity

    由於人們不斷要求更大的無線資料容量，再加上受管制的無線電頻譜已趨飽和，受到青睞的系統不僅要能提供高位元速率，而且必須集中在較小實體區域內，這樣的衡量標準稱為空間容量。
  5. Smart antenna may reduce coggege of electronic engineering of uestc, the cochannel interferences ( cci ), enhance the user capacity and spectrum efficiency, reduces the transmit power and electromagnetic interferences, enhance the transmit efficiency, dynamically divide cells in third generation cellular

    智能天線技術應用於第三代移動通信系統中具有可以減小因頻率復用造成的共通道干擾（ cci ） 、提高頻譜利用效率及增大系統容量、減小發射功率和空間電磁干擾、增加發射效率、對小區進行動態劃分等優點。
  6. It shows that a disadvantag ekists when a crsi is used to measure a step structure in a wavefront, but it is useful to adjust a crsi system with lcslm. 4. according to the didriction effect of an aperture, the spatial resolution of our crsi was analyzed and the transform function of our crsi was calibrated by using the psd method of a step wavefront. and some factors which are associated with the accuracy of our crsi were analyzed too

    四、從光學系統衍射效應的角度分析了本文建立的環路徑向剪切干涉儀的空間解析度，並利用波前功率譜密度的概念對該干涉儀的空間頻率響應特性進行了標定，分析了限制該干涉儀測量精度的主要因素以及徑向剪切比與測量精度的關系，並指出了該干涉儀的測量范圍，結果顯示該干涉儀基本上可用於準確測量中低頻段的波前畸變。
  7. To solve this problem, this thesis will focus on investigation of the following detection methods based on the features of the dsss signal and with the binary - phase - shift - keying dsss ( dsss / bpsk ) signal as an example. 1. the power spectrum of the dsss / bpsk signal is discussed and the detection performance in each power spectrum estimation method is compared in terms of nonparametric methods, parametric methods and subspace methods in power spectrum estimation

    本文針對這一問題，從dsss信號特徵出發，以二進制相移鍵控的直接序列擴頻（ dsss / bpsk ）信號為例，研究了以下檢測方法: 1 .從功率譜估計的非參數方法、參數方法和子空間方法入手，討論了通過不同類型方法估計的dsss / bpsk信號功率譜，並比較了各功率譜估計方法應用於dsss / bpsk信號檢測的性能。
  8. Based on fourth - order cumulant, a computationally efficient method for joint estimating both directions of arrival and ranges of near field sources with known carrier frequency is firstly presented. the proposed algorithm need not any spectral peak searching and the 2 - d parameters are automatically paired. lt is suitable for arbitrary additive gaussian noise environment. in the following section, a 3 - d esprit method for jointly estimating of frequencies, doa ' s and ranges of multiple near - field sources with unknown carrier frequencies is proposed. the parameters estimation are given by the eigenvalues of different matrices. furthermore, its performances are confirmed by several computer simulations

    利用四階累積量，第五章首先給出了一種載頻已知的情況下基於近場源的距離和波達方向聯合估計演算法，通過構造的陣列輸出信號四階累量矩陣使空間信號到達方向和距離估計無需譜峰搜索，且參數自動配對，適合於任意高斯噪聲環境。進一步在第三節提出了一種載頻未知的情況下的多個近場窄帶信號源doa 、距離和頻率聯合估計的3 - desprit演算法。
  9. The basic concepts of second - order coherence theory in describing wavefields are introduced. these concepts are the cross - spectral density function and spectral degree of coherence in the space - frequency domain, and the mutual coherence function and the complex degree of coherence in the space - time domain

    介紹了二階相關理論中描述光場相干性質的基本概念，包括空間-時間域中的互相關函數、復相干度和空間-頻率域中的交叉譜密度函數、光譜相干度。
  10. The pseudo - dynamic test of 1 / 3 - scale model six - story building assembled with hollow shear wall with seams. the internal forces, the deformation and the failure mechansm of the building under earthquake are studied. the rules of frequency, damping and response spectrum are studied. the characters of earthquake response such as structure displacement, interstory drift, action of earthquake, the amplificatory coefficient of acceleration and the rule of strain are discussed. at last, this paper presented the design method of this structure based on the aseismic style and put forward the construction

    進行了帶縫空心剪力墻結構六層樓房的1 3模型的擬動力試驗，研究了結構在水平地震作用下的受力特點、變形特徵、破壞形態等力學性能；得到了結構在不同受力階段的頻率、阻尼、反應譜等動力特性變化規律；討論了結構各樓層的水平位移、層間位移、地震力、加速度放大系數及構件應力分佈規律等結構地震反應特徵；指出了結構的抗震類型、薄弱層及薄弱部位；提出了多層帶縫空心剪力墻結構的第一階段設計方法和相應構造措施。
  11. Because of the affection of noise and signal fading, in order to high data rate access and high quality, wireless communication need new technology to improve the link reliability and enhance the spectrum efficiency. mimo ( multiple input and multiple output ) can enhance the spectrum efficiency and increase channel capacity greatly, and reduce the multipath affection without spectrum band and power increasing. the 3th generation mobile communication wcdma is coming, with the purpose of putting mimo, stbc ( space time block coding ), space diversity into practice of wcdma systems, in order to lay the foundation of 3g toward 4g, this dissertation has done some research under this background

    在發射機和接收機使用多個天線進行數據傳輸的多輸入多輸出（ mimo ）技術，可以在不增加帶寬和天線發送功率的條件下，成倍的提高頻譜利用率，提高系統的通道容量，還可以抗多徑干擾。第三代移動通信wcdma即將到來，為了將多天線技術（ mimo ） ，空間分集技術，空時編碼技術用到wcdma系統中去，為第三代移動通信向第四代移動通信系統平穩過渡奠定一定的基礎，需要做一些理論上的研究。
  12. Fortunately, a novel creative technology, namely multiple - input multiple - output ( mimo ), has provided an innovative solution to this problem. mimo technology utilizes multiple antennas at both transmit and receive ends of the radio link to multiply the capacity and reliability by fully exploiting the space resource within the same frequency band at no additional power expenditure

    可幸的是，多入多出（ mimo ）無線通信技術為解決該問題提供了全新的途徑，它在無線鏈路收發兩端均採用多天線，充分開發空間資源，在無需增加頻譜資源和發射功率的情況下，成倍地提升了通信系統的容量與可靠性。
  13. 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
  14. In the first part, the research progress of cloud motion wind was introduced and the significance of the 1 - d fourier analysis technique was given. in the second part, based on fluctuation theory and fourier analysis, the one dimension fourier analysis technique on cloud motion winds is deduced and demonstrated theoretically. by simulating mathematically on frequency and on space, we not only uncovered two questions in practice, first is phrase folding, second is frequency spectrum overlapping, but also gave methods and suggestions to solve them or avoid them

    本文由六章組成，第一章介紹雲導風技術的研究進展和傅立葉導風技術的研究意義；第二章以波動理論和傅立葉變換為基礎，對傅立葉相位導風技術進行理論推證和誤差分析，通過模擬分析了空間域和頻率域的導風特點，揭示了在導風過程中出現的相位重疊和頻譜混疊兩種現象；第三章通過計算在空間域速度線性變化情況下頻率域振幅權重平均速度（
  15. 2 a mathematical model of the reflected signal based on the frequency modulation continuous wave ( fmcw ) radar, solving the frequency - azimuth estimation of coherent signals by spatial smoothing technology, comparing the resolution of the object based on two - dim music method and that based on two - dim fft

    2討論了在接收dbf條件下，回波信號的二維譜估計技術。建立了基於調頻連續波體制雷達下回波信號的數學模型，並將空間平滑技術推廣到時-空二維譜估計，解決了相干信號源的頻率-方位估計問題。
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