空間頻率向量 的英文怎麼說
中文拼音 [kōngjiānbīnlǜxiàngliáng]
空間頻率向量
英文
spatial frequency vector- 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
- 量 : 量動1. (度量) measure 2. (估量) estimate; size up
- 空間 : space; enclosure; room; blank; interspace
- 頻率 : frequency; rate
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While two ( or more ) electromagnetic waves of the same frequency, same direction of vibration, same phase or constant phase difference superpose in space, the amplitude of composite wave is vector sum of the amplitude of each wave
由兩個(或兩個以上)頻率、振動方向相同、相位相同或相位差恆定的電磁波在空間疊加時,合成波振幅為各個波的振幅的矢量和。According to the guidline, two nd : yag lasers have been designed and set up, one is end - pumped by lower output power ld using a selfoc micro lens, and the other is end - pumped by high output power ld using a pair of lenses are designed, and the characteristics such as output power and power stabilization of both solid - state lasers are investigated. thirdly, when an empty liquid crystal cell is inserted in the cavity of the nd : yag laser pumped by high power ld, the laser can operates in single axial mode. finally, according to the relationship between the laser output power and the longnitudinal a ld - end - pumped nd : yag laser sensor for displacement measurement has been investigated theoretically and demonstrated experimently, the results indicate that when the mean radius of pumping inside the laser cavity is far less than that of the oscilating laser mode, the exponential of the output power is a gauss function of the longitudinal positon of focused spot of ld pumping beam, both the measurement range and the sensitivity are dependent on the incident pumping power, as the incident pumping power is increased, the measurement range is enlarged and the sensitivity is improve d
本文首先介紹了ld泵浦nd : yag激光器的發展狀況、主要特性及其應用,從四能級速率方程出發,推導了ld泵浦nd : yag激光器的閾值、輸出功率和斜效率的表達式,並簡述了激光器的工作原理、結構型式和倍頻方法;其次,以空間相關的速率方程為基礎,提出了ld端面泵浦nd : yag激光器的設計方法,給出了一定泵浦耦合方式下,振蕩光模尺寸、最佳輸出耦合率、泵浦光模尺寸、泵浦光焦斑位置等參數的選取依據,以此為依據,設計了自聚焦透鏡耦合小功率ld泵浦nd : yag激光器和透鏡組耦合高功率ld泵浦nd : yag激光器,對激光器的輸出功率和功率穩定性等特性進行了實驗研究;再次,在帶尾纖輸出的高功率ld泵浦nd : yag激光腔內插入一隻空液晶盒,觀察到了激光器以單縱模運轉;最後,根據泵浦光焦斑端面位置對激光輸出功率的影響規律,提出了ld端面泵浦nd : yag激光位移傳感新方法,並進行了理論和實驗研究,研究結果表明:當激光晶體內泵浦光平均光斑半徑遠小於振西安理工大學碩士學位論文蕩光束腰半徑時,激光輸出功率的自然指數與泵浦光焦斑的縱向位置成高斯變化規律,測量范圍和靈敏度依賴于泵浦功率,隨著泵浦功率的增加,測量范圍擴大,靈敏度提高,當端面泵浦功率為7 . 24w (最大輸出功率為1 . 926w )時,激光位移傳感器的測量范圍和靈敏度分別是13 . 045mm和0 . 148mw / pm 。Pressure sensitivity, harmonic frequency and directive property are important indexes to characterize its performances
聲壓靈敏度、諧振頻率和空間指向性是衡量其性能的重要指標。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。This method constructs covariance matrix by utilizing data vectors in different range lines and projects phase error vector into noise sub - space which is formed by eigendecomposing the covariance matrix
該方法利用不同距離單元的觀測矢量構造協方差矩陣,然後通過對協方差矩陣特徵分解得到噪聲子空間,最後將相位誤差矢量向噪聲子空間投影來估計多普勒調頻率。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。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。Almost any piece of information available at the time of interaction can be seen as context information : identity, spatial information ( e. g., location, orientation, speed and acceleration ), temporal information ( e. g., time of the day, date, and season of the year ), environmental information ( e. g., temperature, air quality, and light or noise level ), social situation ( e. g., who are you with, and people that are nearby ), resources that are nearby ( e. g., accessible devices, and hosts ), availability of resources ( e. g., battery, display, network, and bandwidth ), physiological measurements ( e. g., blood pressure, hart rate, respiration rate, muscle activity, and tone of voice ), activity ( e. g., talking, walking, and running ), schedules and agenda settings
幾乎任何在交互時可用的信息都能被看作環境信息:標識,空間信息(例如:位置,朝向,速度和加速度) ,時間信息(例如:某天的時間,日期,某年的季節) ,環境信息(例如:溫度,空氣質量,光或噪音的級別) ,附近的資源(例如:可訪問的設備,主機) ,可用的資源(例如:電池,顯示,網路和帶寬) ,生理度量(例如:血壓,心率,呼吸頻率,肌肉活動,語調) ,活動(例如:談話,行走,和奔跑) ,日程和內容設定。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。This article presents an analytical formulation or correlating signal subspaces of two closed - spaced vibration modes
摘要本文旨在以向量空間關聯性的方法來分析兩個相近頻率模組的關系。After the image lifting wavelet transformation, its coefficients have some characteristics, for example : the frequency compression characteristic, namely the primitive image energy majority of gathers to the low frequency sub - belt ; spatial compression characteristic, namely high frequency sub - belt energy majority of centralisms in primitive corresponding and so on image edge, outline position ; the coefficient distribution similarity, namely in the
經提升小波變換后,其系數具有如下特性:頻率壓縮特性,即原始圖像的能量大部分聚集到低頻子帶;空間壓縮特性,即高頻子帶的能量大部分集中在原始圖像的邊緣、輪廓等對應的位置;系數分佈相似性,即同一方向上各級子帶系數幅值分佈大體一致。The integrated method of time and frequency domain analysis and rbfnn is given for bearing fault diagnosis. through selecting representative parameters, feature space vector is constructed so the input dimension is reduced and fault classification information retained
通過時頻域分析提取了有代表性的特徵參數,構建了特徵空間向量,既降低了網路的輸入維數,提高了網路的學習效率,又保留了故障分類信息。分享友人