最大噪聲級 的英文怎麼說
中文拼音 [zuìdàzàoshēngjí]
最大噪聲級
英文
maximum noise level-
Turbo codes represent the new code structures, which consist of pccc ( parallel serially convolutional code ) and sccc ( serially concatenated convolutional code ). in this paper, the background of turbo codes are firstly introduced, which includes the base principle of error correction code 、 block code and convolutional code ; the principle of turbo code and the iterative decoding is secondly expanded ; the key decoding algorithm : a revised map algorithm and iterative decoding theory are detailed ; then, a new turbo code structure : hccc ( hybrid concatenated convolutional code ) is presented, and the capacity of this code method is analyzed, the average capacity upper bound is derived ; at last, this code is simulated on awgn ( additive white gaussian noise ) channel and rayleigh fading channel
本文首先介紹了turbo碼的背景知識,包括差錯控制的基本原理、分組碼和卷積碼;然後闡述了turbo碼的基本原理,包括turbo編譯碼器結構及迭代譯碼原理;較為詳細地描述了關鍵的譯碼演算法: ?種改進的最大后驗概率( map )譯碼演算法及迭代譯碼演算法;提出了一種新的turbo碼結構:混合turbo碼(混合級聯卷積碼) ;並用編碼性能聯合界分析方法對混合turbo碼進行了性能分析,得出了其平均性能上界;並在高斯白噪聲通道和瑞利衰落通道上分別作了一些應用研究及計算機模擬實驗。Secondly, compared with some other kinds of comparator structure and based on the preamplifier - latch fast - compare theory, a novel topology of cmos preamplifier latch comparator circuit is presented. considering trade - off between kickback noise and power dissipation, reference resistance value is optimized. according to the encode demands of different stage resolution, clock - control encode circuit is designed
其後,在具體的子adc設計中,對比各比較器類型的優缺點,並基於預放大鎖存快速比較理論,提出一種新型高速低功耗預放大鎖存比較器電路拓撲;根據adc系統所允許的參考電壓最大波動限制,在回饋噪聲對輸入參考電平的影響和功耗之間折衷,確定優化的參考電阻串阻值;根據不同級精度的編碼要求,設計出時鐘控制編碼電路。This thesis explains the necessity of the character recognition technology of the computer at first, describe the meaning in which the handwritten numeral discerns ; pretreatment technology of handwritten numeral recognition, including two value, line segmentation, word segmentation smooth, removing noising, standardization and thinning are discussed two value concretely discusses whole threshold value, some threshold value, dynamic threshold value and utilize space information to carry on threshold, which are several kinds of common method of choosing threshold value, especially utilize space information to carry on threshold value is describe in detail ; adopting to the foundation of thinning based on mathematics morphology, thinning algorithm of serials same and thinning algorithm of protecting shape are discussed ; afterwards, according to principle ' s diagram of the on - line character recognition, by analyzing the structure feature of the handwritten numeral, this thesis has proposed the online recognition te chnology of the free handwritten numeral based on the stroke feature and the online recognition technology of the free handwritten numeral based on the multistage classifying device. detail narrated noise removing, stroke characteristic definition and discernment, distance criterion of whole word match ; then under the foundation of handwritten numeral segmentation, off - line handwritten numeral recognition is researched. especially minimum distance classifying device, tree classifying device and adaptive resonance ( art ) network classifying device is discussed at the same time, believes degree analyses are introduced to integrate a lot of classifying devices ; at the end, the typical application of the handwritten numeral recognition was briefly narrated, its application in extensive data statistics, financial affairs, tax, finance and mail sorting have been explored
二值化時對整體閾值二值化、局部閾值二值化、動態閾值二值化和利用空間信息進行閾值選取幾種常用的閾值選取方法進行討論,特別對利用空間信息進行閾值選取進行了詳細論述;在對通過對基於數學形態學的細化的基礎上,討論序貫同倫形態細化演算法和保形的快速形態細化演算法;然後依據聯機字元識別原理框圖,分析了手寫數字的結構特點,提出了基於筆劃特徵的任意手寫數字在線識別技術和基於多級分類器任意手寫數字在線識別技術,對其中涉及的筆劃識別前的噪聲處理、筆劃間特徵量的定義及識別、整字匹配的距離準則進行了詳細敘述;繼而在對手寫數字的分割的基礎下對脫機手寫數字識別進行了研究,對基於最小距離分類器字元識別、基於樹分類器的字元識別、基於自適應共振( art )網路的字元識別分別進行了詳細討論,並引入置信度分析將多個分類器進行了混合集成;最後簡單闡述了手寫數字識別的典型應用,對其在大規模數據統計、財務、稅務、金融及郵件分揀中的應用進行了探索。Maximum permissible ambient noise levels for audiometric test rooms
試聽室最大可允許的環境噪聲等級Also from waveform polynomials of sequential circuits, a precise clocking method based on multiple - period sensitization is presented. a novel noise estimation method based on boolean process is first presented in this paper, using transition numbers to describe noise effects. then combined with the selection method of long sensitization paths based on waveform sensitization, a test generation approach that could generate the noisiest sensitization waveforms for long sensitizatizable paths is presented
為了適應超深亞微米電路測試的要求,本文建立了一種新的基於布爾過哈爾濱工程大學博士學位論文程論的邏輯級噪聲預測模型,用波形多項式描述的同時發生的跳變數來預測l卜足聲大小,並生成能產生最大跳變數目的輸入波形;然後同基於波形敏化的長敏化通路選擇法相結合,形成一種能產生最大噪聲效應的敏化測試波形生成新方法。Based on our theoretical predictions, we find optimal splicing parameters on fsm - 30s fiber splicer for low loss joints between erbium doped fiber and other single mode fibers. we also experimentally demonstrate a novel three - stage erbium - doped fiber amplifier with high gain, low noise figure, and high output power. finally, a prototype of a gain - clamped fiber amplifier is obtained with high gain ( 26 db ), low noise figure ( 5. 3 db ), high output power ( 17 dbm ), and large bandwidth ( 31 nm )
文章研究了摻鉺光纖( edf )與其他光纖低損耗焊接問題,得到光纖熔接機低損耗熔接的最佳參數,這對摻鉺光纖放大器的科研生產具有一定的指導意義;研究了新型的三段級聯泵浦優配的摻鉺光纖放大器的優化光路結構,得到高增益,低噪聲,大輸出功率的摻鉺光纖放大器;最後研製成功高增益( 26db ) ,低噪聲( 5 . 3db ) ,大輸出功率( 17dbm ) ,寬帶( 31nm )增益箝制摻鉺光纖放大器樣機。In this paper the train running noise level has been predicted with the theory of point sound source. the sound exposure level of a train set pass, equivalent continuous sound level and maximum sound level of a train set pass has been taken as estimate values, and some kinds of affixation attenuation on the course of noise propagation is considered, then the corresponding visual software has been developed. these make it convenient and precise to predict the noise level
本文從點聲源的理論出發,對列車運行噪聲進行預測計算,採用一列車通過時的單發暴露聲級、時間特性的最大聲壓級和一定時間內的等效聲級等作為噪聲評價量,並考慮了噪聲傳播過程中的各種附加衰減,編制了相應的可視化軟體,使噪聲預測計算方便、準確。The first part of the paper is designing the testing project for grounding resistance and insulation resistance in a new way. using 16bits ad converter with programmable control amplifier replaced the way which used changing resistance to change measure range. lt is not only improved testing precision and develop the system expediently, but also reduced the area of the circuit boardwith the new way. in order to make the electric implement safety testing system have upstanding expansibility, the software and hardware of the system adopted the modularization design. adopted mcu atmegal28 as a master mcu which control mmi, realtime clock and communication with slaver mcu. atemga8 as the slaver mcu to realize testing function. so it is easy to add or reduce the testing project. the testing implement system has been developed successfully, and the comments for the system is that it has high precision, high expansibility and easy maintain. but considering the electric implement system should have intelligence and humanity abi lity. so this paper bring forward a scheme of electric equipment safety testing embedded system with speech control. after introduce the basic theory of speech recognition, the paper expatiate the characters of this system. the system is a noise conditon, not special people, small glossary, insulation word system. with these characters design the speech recognition as fellow. utilizing cross zero ratio and short energy to ensure jumping - off point and end point ; adopting mfcc as the character parameters of speech recognition ; the character parameters than be recognized by dtw. in order to ensure the credibility of this project, first realized by matlab in computer
在介紹了語音識別的基本原理后,闡述了本系統的特點:本系統是一個噪聲環境下非特定人、小詞匯量、孤立詞的語音識別系統。根據本系統的這些特點設計了如下語音識別方案:利用過零率和短時能量相結合的方式確定語音端點;採用mel頻率倒譜系數( mfcc )作為語音識別的特徵參數;得到的特徵參數最後通過動態時間規整( dtw )的模式識別方法進行識別。為了確保本系統實現方案的可靠性,首先通過計算機利用matlab軟體來模擬,在演算法模擬實現后又進一步增加環境的復雜性:加上較大的環境噪聲、突發性的噪聲等,再通過修改參數、修改參考模板、兩級識別等各種提高語音識別精度的方法來提廣東工業大學工學碩士學位論文高識別率。Moreover, an optimized lna structure - inter - stage inductor matching - is presented, which can achieve conjugate match of two stages, maximize the forward transmission, sequentially increase the signal noise ratio ( snr ) and reduce the noise figure
並提出了級間匹配電感的設計方案,此優化結構能實現兩級之間的共軛匹配,使信號的正向傳輸最大化,從而增大信噪比,降低了噪聲。At the same time this paper calculates the effect of train velocity on noise propagation, when mach number is 0. 1, sound velocity less effects on noise level ; when mach number is 0. 4, the difference value is about 2db whether to consider the sound velocity. so when the train velocity is not very high, the effect of sound velocity may not be considered
本文同時計算了列車運行速度對噪聲傳播的影響,當馬赫數為0 . 1時,聲音的傳播速度對聲級的影響是很小的,當馬赫數為0 . 4時,考慮聲速與不考慮聲速影響的最大值的差值大約為2db左右,因此在列車速度不是很高的情況下可以不考慮聲速的影響。Through redesigning of pipe system to alter its character and using the ways to isolate vibration and reduce vibration, it is yielded very good results of reducing the vibration and noise. in some points the acoustic pressure level drops very much, such as in the standard point of number one pump the acoustic pressure level drops 15db ( a ) and in the standard point of cistern also drops 15db ( a ), and in the highest point of the acoustic pressure before redesign drops from 105db ( a ) to 44db ( a ), and in the second floor the acoustic pressure level have reached the requirment
通過對管道結構的改造,減振和隔振措施的有效使用,使供水系統的振動和噪聲得到了有效的控制:使一號泵前的標準點和蓄水池前標準點的噪聲聲壓級都降低了15db ( a ) ,管道上測點的振動量降低了90 ;二樓居民門外的噪聲從55db ( a )降到25db ( a ) ,遠低國家標準35db ( a ) ;在改造前噪聲最大點西側蓄水池的噪聲也由105db ( a )降到44db ( a ) 。How to reduce noise figure of operational amplifier are studied in this paper. through design of a low - noise opa, introduce low - noise design of the input stage in detail. and with the analysis of computer, suitable sizes of the input apparatus are choosed. at last, by simmulation and verification on this opa, the result is satisfied
研究了如何從電路結構上減少運算放大器的噪聲,以一種低噪聲運放為例,著重介紹輸入級設計,並藉助計算機分析選擇合適的輸入器件尺寸,最後通過對運放噪聲的模擬驗證,得到了滿意的結果。分享友人