local frequency 中文意思是什麼
local frequency
解釋
本振頻率-
We discuss the forecast method which based on wavelet neural networks by combining good time and frequency local analysis ability which wavelet analysis possesses with learning ability which neural networks possesses, and bring forward a frondose, banausic algorithm in this dissertation0 also, a essential thinking of combined forecast based on wavelet neural networks is described and a essential trait of combined forecast based on wavelet neural networks is pointed out
結合小波分析所具有的良好的時頻局部化分析能力和神經網路所具有的學習能力，討論了小波神經網路預測方法，並給出了其具體、實用的演算法。文中還描述了基於小波神經網路組合預測的基本思想，指出了利用小波神經網路進行非線性組合預測的特點。 -
By using irm, heterodyne receiver with good image rejection and mmw - to - if once frequency conversion can be realized, which simplified receiver constitution prominently. the number of local oscillation ( lo ) sources is reduces and electromagnetic compatibility ( emc ) of mmw system is improved. also, the size, weight, power consume and cost of mmw receiver is reduced
採用毫米波鏡頻抑制混頻器，可在保證鏡頻抑制性能的前提下，採用1次變頻接收機，從而大大簡化接收構成，減少本振數量，改善毫米波系統電磁兼容性，減小接收機體積、重量、功耗，並降低成本。 -
The experimental result expresses that the frequency doubler - power amplifier sets of ka - band can supply good local oscillation source for " millimeter - wave front - end of " lmds " ". the model has the advantages of low cost, small size and high reliability
實驗結果表明，倍頻放大組件能夠為lmds毫米波前端提供很好的本振源，並且具有成本低、體積小、可靠性高等優點。 -
Intermodulation suppression for fh ( frequency hopping ) receiver is designed by selecting the intermediate frequencies and changing group of filters, local oscillation ( lo ) frequency, bandwidth of lo frequency under the condition that receiver configuration, sensitivity, dynamic range, instantaneous bandwidth and precision of frequency measurement are fixed
摘要針對跳頻接收機的體制和靈敏度、動態范圍、瞬時工作帶寬、測頻精度等設計參數，通過改變預選器組成、本振頻率和本振帶寬，分析接收通道的中頻選取原則，以實現跳頻接收機的互調抑制設計。 -
Delay line oscillator is composed of broadband amprifer adjustable attenuator and saw sensor device. after output signal of delay line oscillator is smoothed, it mixes with 109mhz local oscillation signal. its differential frequency signal is smoothed by low - pass filter trimmed by shaping circuit and processed by digital processing circuit
延遲線振蕩器由寬帶放大器、可調衰減器和聲表面波質量傳感器件構成。延遲線振蕩器輸出信號經濾波后與109mhz的本機晶體振蕩器輸出信號相混頻，通過低通濾波取其差頻，並經整形後由數字信號處理電路處理。 -
Wavelet transform, which has a multi - resolution analytic character, is a time - scale ( time - frequency ) analytic method of information. moreover, as both of its time - window and frequency - window can be changed it processes the ability of expressing local characters of information in time - frequency domain
小波變換是一種信號的時間尺度（時間頻率）分析方法，它具有多解析度分析的特點，而且在時頻兩域都具有表徵信號局部特徵的能力，是一種窗口大小固定不變但其形狀可改變，時間窗和頻率窗都可以改變的時頻局部化分析方法。 -
In this system two oscillator are used for mixing. pll for high local oscillator and dds + pll for low local oscillator. by making full use of favourable narrow - band tracing filter character of pll and by combining the merits of dds such as super fine frequency resolution, high frequency accuracy, very fast frequency hoping with it, the pll / pll + dds frequency synthesizer presents wide band high quality source and super small frequency hoping step
系統採用兩次混頻，其中高本振的設計採用pll鎖相環頻率合成來實現，充分發揮了鎖相環頻率合成器的優良特性，實現了系統所要求的高質量寬頻帶本振源；低本振採用pll + dds頻率合成來實現，結合pll優良的鎖相特性與dds的高頻率解析度、高頻率精確度等優點，實現了頻率的小步進高精度合成。 -
The major job is manufactured a transmitter, which has three upmixer channels. its function is to up convert the signals from c - band to ka - band. the input local oscillator is provided by a low frequency crystal oscillator which has a good performance of phase noise, through 512 times multiply to ka band. this sysetem is used in the laboratory as transmitter source of the fuze, for the multidimensional objects in practise, which lead to the complexity of the reflect signal, so the amplitude, frequency and the phase of the transmit signals both have a key role in dealing with the reflection signals. therefore, this system requires for both the coherence of the single channel ’ s amplitude, phase and multi channels
本文的主要工作是應用戶要求製作一具有三發射通道的上變頻系統，可以將c波段的微波信號上變頻到ka波段的毫米波信號。系統的本振輸入基頻由一相位噪聲非常好的低頻率晶振提供，經過512次的倍頻放大至ka波段。本系統作為實驗室中引信的發射源，由於目標反射信號具有時變的多維性，反射信號變得極為復雜，在信號處理時，不僅信號幅值、頻率有決定意義而且相位關系也很有決定意義。 -
A region growing phase unwrapping algorithm based on local frequency estimation for interferometric sar
一種局部頻率估計的區域生長相位展開方法 -
" the project aims to develop middleware for manufacturing, retail and distribution companies in the prd region to integrate rfid radio frequency identification data with back - end systems, business processes and logistics and scm supply chain management solutions, " said professor tan chung - jen, director of eti, hku. " eti will head the development of the core technology and collaborate with partner universities to develop applications and pilot projects with local enterprises in the region.
這個專案的目的是為珠三角地區的製造、零售、物流等行業開發一套中間件，將rfid資料與企業的后臺系統、商業過程以及物流和供應鏈管理等系統集成一起，香港大學電子商業科技研究所（ eti ）總監譚崇仁教授指出， 「 eti將領導核心技術的研發工作，與合作大學一起開發應用程式，並在珠三角地區的企業中實施試驗專案。 -
Base station identity code. an attribute of a gsm ( global system for mobile communications ) cell which is a code allowing a distinction between local cells having the same radio frequency
基站識別碼。 gsm （全球移動通信系統）蜂窩小區的一個屬性，通過基站識別碼，不同的本地蜂窩小區可以使用相同的無線頻率。 -
Second part - the main contribution and research results of this paper are focused on as follows : ( 1 ) how to use the measurements of a dual frequency gps receiver to determine the ionospheric delay correction model for single frequency gps of a local range ; ( 2 ) how to separate the instrumental biases with the ionospheric delays in gps observation ; ( 3 ) how to establish a large range grid ionosphere model and use the gps data of chinese crust movement observation network to investigate the change law of ionospheric tec of china area ; ( 4 ) how to improve the effectiveness of correcting ionospheric delays for waas ' s users under adverse conditions. ( 5 ) how to establish the basic theory and the corresponding framework of monitoring the stochastic ionospheric disturbance using gps ( 6 ) how to improve the modelling ability of ionospheric delay according to its diurnal, seasonal, annual variations based on gps ; ( 7 ) how to meet the demand of correcting the ionospheric delay of high - precision orbit determination for low - earth satellite using a single frequency gps receiver 1 extracting ( local ) ionospheric information from gps data with high - precision the factors are systematically described and analyzed which limit the precision of using gps data to extract ionospheric delays
二、具體研究工作的系統報告，主要集中在以下幾方面：研究如何利用單臺雙頻gps接收機的觀測信息確定電離層延遲改正模型，為小范圍的單頻用戶服務；研究如何實時分離gps觀測中的儀器偏差與電離層延遲；研究如何建立較大區域的電離層格網模型，進而初步設想利用中國地殼運動觀測網路深入研究我國領域的電離層的電子濃度變化規律；研究單頻用戶在不利條件下，如何更好地利用電離層延遲改正信息；研究利用gps監測隨機電離層擾動的基本理論和框架方案；研究如何綜合顧及電離層的周日、季節和年變化，進一步提高利用gps模擬電離層延遲的能力；研究如何實現星載單頻gps低軌衛星的精密測軌中的電離層延遲改正要求。 -
Furthermore, the isoline maps of mean wind pressure coefficients and rms wind pressure coefficients of the structure under various wind directions are plotted. in the matter of theoretical analysis, modeling with finite element method, using the local mean wind pressure coefficients and time history of fluctuating pressures determined in wind tunnel, the wind - induced dynamic responses for long - span grid roof structures are calculated in frequency domain and time domain separately
在理論分析方面，建立合理的有限元模型，利用剛性模型風洞試驗獲得的各種不同情況下屋面各節點的平均風壓系數和脈動風壓時程，在頻域內和時域內進行了大跨網架屋蓋結構的風振響應分析。 -
10mb s radio - frequency cables - part 3 - 2 : coaxial cables for digital communication in horizontal floor wiring - detail specification for coaxial cables with solid dielectric for local area networks of 185 m reach and up to 10 mb s
射頻電纜規范.第3部分:平面層布線數字通訊用同軸電纜.第2節:有效半徑達到185m速率在10mb s -
10mb s radio - frequency cables - part 3 - 3 : coaxial cables for digital communication in horizontal floor wiring - detail specification for coaxial cables with foamed dielectric for local area networks of 185 m reach and up to 10 mb s
射頻電纜規范.第3部分:平面層布線數字通訊用同軸電纜.第3節:有效半徑達到185m速率在10mb s -
Variable frequency local oscillator
變頻本振器 -
Select installation and then antenna setting, and set respectively the local oscillator frequencies of the high - frequency tuner of 146, 138ku, 138c band and so on
選擇安裝里的天線設定，分別設置146 、 138ku及138c波段等等的高頻頭本振頻率。 -
It is shown that the excessive local oscillator drive deteriorates the conversion gain of the mixer at high frequencies, a trend not shown in the low frequency approximation
我們征明了在高頻下，過大的本振將使得混頻器的轉換增益減小。這一趨勢無法由低頻近似模型給出。 -
Unlike the monostatic sar, two independent local oscillators are used for up / down conversion in bistatic case, so low frequency components of phase noise cannot be cancelled
雙基地sar用兩個獨立的本振分別實現上變頻和下變頻，相噪低頻分量不能相互抵消，形成與單基地sar不同的低頻相噪。 -
The therapeutic generation of local heat in body tissues by high - frequency electromagnetic currents
透熱療法用電極或其它器械通過各種波長的高頻電流使在組織內產生熱以達到內外科治療目的
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