限用頻帶 的英文怎麼說
中文拼音 [xiànyòngbīndài]
限用頻帶
英文
restricted frequency band-
In all kinds of complicated network, oriented linking and unlinking, communication frequency resource is strained, and bandwith to transmitting audio frequency signal is too restricted, complicated and fluky, while audio frequency data exponential have been increased in the last several years. under the circumstances, based on the research of predecessor, this paper studies wavelet analysis ' s maths gist and practices significance on signal process, and puts forward a optimized wavelet package condensation arithmetic to process audio frequency data, which gives attention to coding efficiency, multirate and compression delay. simulation experiment on the arithmetic has been done by matlab
針對無連接和面向連接的各種復雜網路環境下，通信頻帶資源緊張，音頻傳輸帶寬有限且復雜多變，而各種音頻數據又日益增多的局面，本文研究小波分析在信號處理方面的數學依據和在數據壓縮方面的實際意義，在前人不斷工作的基礎上，提出了一種優化小波包變換編碼方案用於音頻數據的壓縮演算法，兼考慮了編碼效率、多碼率和壓縮時延多個方面，並在matlab環境下做了模擬實驗，對各種音頻信號及多種小波函數做了模擬結果比較，實驗結果證明該演算法可以在一定計算復雜度下可以很好地改進壓縮效果，達到多碼率下實現實時編解碼的過程，在高速dsp晶元等硬體設備支持下，可以有效應用於實際復雜多變信源編碼。The plan can generate lots of ss codes, so that it can solve the contradiction between limited bandwidth and infinitude requirements of increasing customers in present communication system and it has ability of secrecy too
並能夠產生大量的擴頻碼地址，可較好的解決現行通信系統中有限帶寬與日趨增加的無限用戶需求之間的矛盾。The factors limiting the frequency band of the wide - band amplifier are introduced. through analyzing the effects of the intrinsic parameters and parasitical on the frequency characteristics, a method of improving fr of mosfet by using short channel device and making mosfet work at the saturation region through raising vgs is put forward ; the effects of different kinds of circuit configurations on the frequency characteristics and the junction voltage on the voltage pattern circuit, current pattern circuit and frequency characteristics are analyzed. according to the linear theory of transconductance which is applied in the bit circuit, the current pattern amplifier circuit, current transfer circuit and output circuit which consist of mosfet and the wide - band amplifier composed of them are put forward
介紹了限制寬帶放大器頻帶寬度的因素，通過分析mosfet的本徵參數、寄生參數對頻率特性的影響，提出了採用短溝器件、使mosfet工作在飽和區、抬高柵源電壓等提高mosfet特徵頻率的方法；分析了不同電路組態對放大器頻率特性的影響、節點電壓對電壓模電路、電流模電路頻率特性的不同影響，根據應用於雙極晶體管電路的跨導線性原理，提出了採用mosfet構成的電流模放大電路、電流傳輸電路、輸出電路以及由它們所組成的寬帶放大器，獲得了良好的頻率響應。Due to the hardware characteristic ' s limitation, such as the poor speed of a / d, d / a conversion and dsp process, the most part of sr system adopt middle course. that is to say, by using the special digital converter or running relevant arithmetic, it converts the radio signal to intermediate frequency signal and completes the base - band signal process that is n ' t the veriest sr and is named " software defined radio ( sdr ) "
由於受到硬體性能如a d 、 d a及dsp晶元處理速度的限制，目前的軟體無線電系統多採用折中的實現方案，增加專用的數字變頻器或者運行數字變頻演算法，將射頻信號變頻到中頻，然後再進行基帶信號處理，這樣的軟體無線電系統又被稱之為「軟體定義無線電」 ，它並不是真正意義上的軟體無線電。Presents the model proposed for analyzing the vibration characteristics of shrouded blades and their calculation method by employing a wave propagation theory and modal synthesis technology coupled with a finite element method from the view point it is possible not only to conduct frequency modulation of the shrouded blades of a gas turbine, but also to utilize the friction effects between them to dissipate energy, thereby attaining the aim of vibration alleviation, as shrouded blades have been widely used in the design of high - speed turbomachinery, such as modern gas turbines and steam turbines, and with the shrouded blades forming an integral whole in a centrifugal force field, the vibration characteristics of the whole ring of blades are different from those of a single isolated blade, and this makes it essential to take into account the integral effect of blade shrouds, concludes from the calculation examples and engineering application that the above approach is valid and correct along with the possibility of considerably reducing the scale of calculation and analysis, and points out it is necessary to take into consideration the coupled effect of the whole ring of blades while the dynamic characteristics of shrouded blades is being analysed
帶冠葉片不但能調頻，還可以利用葉冠之間的摩擦效應來耗散能量，達到減振的目的.帶冠葉片在離心力場中形成一整體，其整圈葉片振動特性不同於單個孤立葉片，需考慮葉冠的整體效應.利用帶冠葉片系統的循環對稱性，提出了採用波傳播理論和模態綜合技術，結合有限元方法研究燃氣輪機帶冠葉片振動特性的分析模型和計算方法.算例和工程應用證明了該方法是效性的、正確的，並可以大大降低計算分析規模.研究表明帶冠葉片動力特性分析時必須考慮整圈葉片的耦合效應Accurate simulation of switch circuit is needed in pin switch design, while limited by assembling techniques, serial resonance and channel inter - coupling exist in the common joint that bring a lot of difficulties for simulation. 2 - dementions simulation software can not establish accurate circuit mode for pin diode switch which gives simulation error, and it costs much more time with 3 - dementation simulation software, which is not applicable in practice for pin switch design
Pin開關的設計中需要對開關電路進行準確模擬，然而高頻、寬帶、多擲pin開關受裝配工藝的限制，開關公共結點附近存在著串聯諧振和相互耦合，給pin開關的準確模擬帶來了困難:二維模擬軟體很難對電路進行準確建模，模擬誤差較大;三維模擬軟體耗時過長，難以在實際設計中應用。This machine is used for straight - line bevel cutting and bevel grinding and polishing for flat glass, in certain condition, it can be also used in bevel cuttig, bevel grinding and polishing for soft stone panel. the contrilling system adopts plc, it can accomplish automatic grinding cutting after entering processing parameter, convery speed adopts speed adjustment of fre quency conversion, direct drive of wheel head motor, all motions for joining in parameter adjustment completely adopt straight - rolling guide - track with front beam and wheel head lifting lntegrally. the transmission of input and output adopts synchronization tooth belt and photo - electricity switch positioning, and position limitation of two pass is much more reliable
Sxm371pa型玻璃直線斜邊磨邊機是用於玻璃直線斜邊斜切，斜磨及光拋的專用設備，在一定條件下也可以用於軟石板材的斜切斜磨及拋光。控制系統採用plc控制。輸入加工參數后可自動完成磨削傳送速度採用變頻調速，磨頭電機直接傳動，所有加工參數調整運動副全部採用直線滾動導軌，前梁與磨頭整體升降，輸入輸出傳送採用同步形帶，光電開光定位，雙行程限位更安全可靠。In the terms of interpolation, the image reconstructed from nearest interpolation or linear interpolation has good edge but serious noise ; reconstruction from 4 * 4cubic interpolation or three b - spline or three - order lagrange interpolations has better local character. 2 x 2cubic interpolations which has both better edge and local character is the ideal interpolation, the following is the basic principle during reconstruction : ( 1 ) the more width of interpolation, the more number of summation and the more order of interpolation polynomial, the higher of density resolution ; ( 2 ) the more of interpolation polynomial and width of interpolation, the more of reconstruction time simultaneously, aimed at eliminating the effects of noise contained in projection data, in this paper, author analysis cause and effects of common artifacts. importantly, discusses convolution back - projection reconstruction algorithm with a shift axis of rotation has been derived for correcting images that acquired with a divergence axis of rotation using the fan beam geometry with an angle - equaled detector
在ct圖像重建時，選擇有限帶寬窗有較好的空間解析度，三角形窗有較好的密度解析度，選擇餘弦窗則使得空間解析度與密度解析度的折衷；從窗函數的頻譜角度來講，可以用於圖像重建的一個良好的卷積窗函數應該具備以下條件： （ ? ）小的3db帶寬b ，即最小的主瓣寬度； （ ? ）最小的旁瓣最大峰值a ； （ ? ）最大的旁瓣峰值衰減速度d ；就內插函數而言，臨近點內插與線性內插重建圖像噪聲大，但有較好的邊緣與細節； 4 4三次內插、三次b -樣條與四次拉格朗日多項式內插圖像平滑，局部特性較好。The satellite - telecommunication has a serial of characteristic such as long distance, large coverage area, wide communication band, big transmission capacity, high quality, it has made a rapid progress in the last decades and become one of the most powerful communication methods today
而衛星通信具有通信距離遠、費用與通信距離無關、覆蓋面積大、不受地理條件限制、通信頻帶寬、傳輸容量大、適于多種業務傳輸、可進行多址通信、通信質量高等一系列特點，幾十年來獲得了迅速的發展，成為現代強有力的通信手段之一。Secondly the detection precision is only related to the synchronization phase but not to the amplitude of the mainline voltage because that it uses the optimized pulses synchronous with the mainline voltage as modulation signals. thirdly it decreases the requirement of the input low pass filter and eliminates the error resulting from the direct component and even harmonics of load current. the most significant merit is that it can eliminate the effect of a few low order odd harmonics and the detecting circuit is easy to be implemented
模擬和實驗結果表明該方法的主要優點有：不需使用乘法器進行信號調制，調制信號採用與電網電壓同步的優化特定脈沖，其檢測精度只與同步相位有關，而與電網電壓幅值無關；降低了對輸入低通濾波器的通頻帶要求，直流和偶次諧波分量對檢測精度沒有影響；突出的優點是可以消除有限個低奇次諧波對檢測結果的影響。Connectors for electronic equipment - part 4 - 115 : printed board connectors - backplane connector for infiniband equipment
電子設備連接器.第4 - 115部分:印製板連接器.無限頻帶設備用印製板背面連接器Connectors for electronic equipment - printed board connectors with assessed quality - backplane connector for infiniband equipment
電子設備用連接器.經質量評定的印製板連接器.無限頻帶設備用印製板背面連接器In order to increase the efficiency on using limited frequency resource, orthogonal polarization is normally adopted for frequency reuse, thus offering double bandwidth at the certain working band
為了充分利用有限的頻譜資源，衛星通信採用正交極化頻率復用方式，在給定的工作頻段上提供雙倍的使用帶寬。Electromagnetic compatibility - part 3 : limits - section 8 : signalling on low - voltage electrical installations - emission levels, frequency bands and electromagnetic disturbance levels
電磁兼容性.第3部分:限值.第8節:低壓設備用符號.輻射級頻帶寬和電磁干擾級別The iboc technology, as proposed by the us - based ibiquity digital corporation, is also known as hd radio. it is designed to operate in the existing am and fm bands by attaching digital data to the sideband of analogue signals. the attached segment can either be a separate radio channel or other data
Iboc是美國ibiquity digital corporation所推廣的制式，又命名為hd radio ，它被設計成可以在現行的am和fm頻帶內運行，在模擬訊號的邊旁加上數碼訊號，它可以是電臺聲音廣播或是其它的數據，但由於頻寬的限制，最大約是200kbps系統設計雖然善用有限的頻譜，但技術上較為覆雜，目前正發展第二代產品。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It has been widely applied in personal communications, mobile communications and the field of broad band wireless access, and it has also been regarded as the main air access of the third generation mobile communications, because comparing with tdma and fdma, cdma has greater system capacity, higher frequency efficiency and stronger anti - interference ability, at the same time it still has the potential of solving the conflict of limited frequency resource and limitless user request
相對于tdma ， fdma等多址技術而言，它具有系統容量大，頻帶利用率高，抗干擾能力強，保密性能好等優越性，同時還具有緩解有限頻帶與無線用戶需求之間矛盾的潛力，因而在個人通信，移動通信，寬帶無限接入領域都得到了廣泛的應用，也被普遍認為是未來第三代移動通信的主流空中介面技術。The vertical delay stacked source obtains optimum matching with wall rock by controlling the charge mode and the excitation velocity, and maximum utilizes its energy. thus the seismic signal with the high frequency abundance and frequency bandwidth wide be obtained
垂直延遲迭加震源通過控制裝藥方式和控制炸藥速度來達到與圍巖的最佳匹配，最大限度的利用其激發的能量，激發出高頻成份豐富、頻帶寬、高頻能量高的地震信號。The inversion ' s resolution is restricted by seismic sampling rate, dominant frequency and bandwidth used a practical model to prove, and two difference concepts are put forward between seismic resolution and stratigraphic resolution
用實際模型論證反演的解析度與地震資料解析度的關系，認為反演的解析度受地震資料的采樣率、主頻和有效頻帶的限制，並提出地震分辨和地層分辨兩個不同的概念。The most important specification of the level measurement system is the accuracy. the range measurement accuracy of a fmcw radar is strongly affected by the stability and the linearity of the frequency modulation. thus the vco ' s nonlinearity correcting method is discussed
利用fft （ dft ）頻譜估計頻率精度受fft頻率量化（即譜線之間的間隔）的限制，對應的fmcw雷達的距離估計精度則受掃頻帶寬的限定。分享友人