選擇率 的英文怎麼說

中文拼音 [xuǎnzhái]
選擇率 英文
selectance
  • : Ⅰ動詞1. (挑選) select; choose; pick 2. (選舉) elect Ⅱ名詞(挑選出來編在一起的作品) selections; anthology
  • : 擇動詞(挑選) select; pick; choose
  • : 率名詞(比值) rate; ratio; proportion
  • 選擇 : select; choose; opt; election; choice; culling; alternative
  1. And then facing the problem of the channel estimation of the adaptive modulation system, we conclude out the channel estimation algorithms on maximum likelihood ( ml ) estimation and maximum a posteriori ( map ) estimation under the condition of flat fading channel and selective fading channel in detail. to meet flat fading channel, we simulate the relationship of the ratio between the error covariance in map estimation and ml estimation and pilot symbol message length. the conclusion can be drawn from these results

    接著,對自適應調制系統中的通道估計問題難點,詳細推導了平衰落通道條件下和性衰落通道條件下最大似然( ml )估計和最大后驗概( map )估計演算法,針對平衰落通道,我們模擬了map估計和ml估計的方差與導頻符號長度的關系,模擬結果表明,錯誤方差受多譜勒頻的變化影響最大,並且對實際的自適應調制系統,導頻符號長度的取值超過20個符號長度時, map通道估計明顯優于ml通道估計。
  2. They are jinfo mountain in nanchuan county ( natural protection section ), wuling mountain in qianjiang county ( national emphases forest demonstration county which forest cover rate is beyond 50 % ) and zhongliang mountain in beibei county ( artificial destruction is very grave ). some main land use patterns i. e. woodland, garden, infield, abandon infield, shrub and grassplot are selected in those three sample sites. four aspects on soil fertility index of karst environment under different land use patterns in these three sample sites, are revealed in this paper, by using the field test, indoor measure and analysis, outdoor experiment and field investigation, and the knowledge and technique of soil, ecology, physics and chemistry etc. they are physical characteristic ( effective soil thickness, organic layer thickness, soil texture, water - stable aggregate and soil water etc. ), chemical fertility ( organism, omni - n, omni - p, omni - k, alkali - nitrogen, available p, available k and rapid available k etc. ), soil animalcule ( bacteria, fungi, actinomyces and their grosses ) and soil - seed - pool ( plant community diversity index ) in karst ecosystem

    本研究以重慶市的南川金佛山(自然保護區) 、黔江武陵山(國家重點退耕還林示範縣,森林覆蓋50以上)和北碚中梁山(遭人為破壞嚴重)典型巖溶區為對象,了幾種重要的利用方式,包括林地、果園、耕地、棄耕地和灌草坡,採用野外巖溶生態調查和室內試驗測量分析相結合的方法,以不同土地利用方式巖溶土壤肥力為重點,對不同土地利用方式土壤肥力特徵進行量化分析,找出巖溶土壤肥力差異的主要方面及其根本原因,論文主要從土壤剖面物理退化指標(有效土層厚度、有機質層厚度、質地、團聚體、水分含量等) ,化學肥力退化指標(有機質、全n 、全p 、全k 、堿解n 、速效p和速效k等) ,樣地土壤微生物指標(細菌、真菌、放線菌數量及總量)以及樣地土壤種子庫植物群落多樣性等4個方面對重慶典型巖溶區的土壤肥力特徵進行了較為詳細的分析研究,為巖溶地區士壤資源的合理利用及結構的調控管理提供依據。
  3. Fierce competition has resulted in a vast selection of service options, as well as airtime rates at as low as nt 3 per minute

    在電信業者的激烈競爭下,用戶不但可以有多元化的,在費上最低也已經降到一分鐘新臺幣三元左右。
  4. If the velocity of atoms is near to zero, the light for ces will tend to confine the atoms near to nodes and antinodes. the stability depends on the magnitude of the negative slope of the light force, the depth of the potential well and the momentum diffusion coefficient. it is important to select the parameters, e. g

    如果通過激光冷卻能使原子速度降至很小甚至為零,光壓力的作用將使原子被較穩定地囚禁于激光駐波場的節點和反節點處,其穩定程度取決于該處光壓力曲線負斜的大小、對應勢能的勢阱深度以及動量擴散系數的大小,因此,如何在實驗中合理激光強度、失諧量等顯得尤為關鍵。
  5. And understanding and studying the spectral features and variation rules of geo - targets in the experimental area, raising that it is the basis of geo - targets information collection with imaging spectrometer data to understand spectral features and variation rules of geo - targets, realizing that in a great extent spectral - integrated - form - based classification method can remove the phenomenon of " different spectrum with same objects " resulted from reflection ratio curve translation because of the angle change among sensor, targets and observation direction, and the average and variance images can be introduced to solve the problem of two kinds of geo - target with similar spectral forms and much different values of whole reflection ratio. it is suggested that " red edge " range bands of vegetation, which has close relationship with vegetation cover and biomass, is the main characteristic bands and important basis for careful vegetation classification and quantitative retrieval, and pixel - based derivative spectral analysis is very useful for removing the effects of soil background values and quantitatively retrieving vegetation biomass and cover. the remote sense quantitative retrieval model is developed for main appraisable factors of desertification monitoring assessment with imaging spectrometer data and then the applicability of model is analyzed

    研究結果如下:首先針對荒漠化地區的地物特徵,對高光譜數據不同波段的數據質量、波段組合進行了評價,提出了適用於荒漠化監測的基本波段集;初步了解和掌握了研究地區的地物光譜特性及變異規律,進一步明確了掌握地物光譜特徵和變異規律是用成像光譜儀數據提取地物信息的基礎;發現了基於光譜整體形狀的分類方法在很大程度上能夠消除由於傳感器、地物目標觀測方向之間的角度變化引起的反射曲線整體平移的「同物異譜」現象,對于譜形相似而整體反射的值相差較大的兩類地物,通過引入均值和方差圖像參與分類得到解決;研究還表明在植被「紅邊」范圍內的波段是進行荒漠化監測的主要特徵波段,這些波段與植被生物量和蓋度都有密切的關系,是開展精細植被分類研究和植被定量反演的重要基礎;像元的導數光譜分析可以消除土壤背景的影響,是進行植被生物量和蓋度定量反演的有力工具;建立了荒漠化監測主要評價因子的定量反演模型,並分析了模型的適用性。
  6. The baud rate can be selected between 20k baud and 1m baud

    波特可以在20k到1m之間。
  7. Test study on two biocides, namely quaternary ammonium salt and isothiazolinelcetone, commonly used in circulatory cooling water system has been carried out, obtaining the relationship among dosage, actuation time duration, and the killed persontage, and putting forward the principle and points needing attention for selecting the biocide

    摘要對火電廠循環冷卻水系統常用的兩種殺菌劑季胺鹽及異噻唑啉酮進行了試驗研究,得出加藥量、作用時間與殺菌的關系,並提出殺菌劑的原則和注意事項。
  8. Main outcome measure percentage of questions correct on a biostatistics / study design multiple - choice knowledge test

    主要結果通過對生物統計學/研究結果知識多項題測試回答正確來衡量。
  9. Opening capital account and the choice of exchange rate of rmb

    資本項目開放與人民幣匯制度的
  10. In particular, feature selection removes irrelevant features, increases efficiency of learning tasks, improves learning performance, and enhances comprehensibility of learned results

    特徵能夠移除不相關特徵,提高學習效,改善學習性能,增強學習結果的可理解性。
  11. Feature selection, as a preprocessing step to data mining, is effective in reducing dimensionality, removing irrelevant data, increasing learning accuracy, and improving result comprehensibility

    屬性作為數據挖掘過程中的一個重要步驟可以有效地降低特徵維度,去除不相關屬性,提高模型準確以及增加模型的可解釋程度。
  12. The theory overall illuminates how the investment company proceeds the stock choice and turns the stock choice into the concrete number by turning six factors given weights that affect the result of the stock choice into the probability of the stock choice by the quantitative method. the important points lie in : 1 considering the external environment, the growth nature, the venture and the corporate v alue ; 2 overcoming the non - comparability of the financial ratios between the corporations of different lines

    此理論從公司的外部環境和公司的內部因素全面地闡述了投資公司如何進行股票,以及通過對成長性、公司所處的風險、宏觀及行業、公司的價值和處于不同行業的企業間財務比進行量化處理,將影響股票的六大因素賦以權值后轉化成股票的可能程度值,從而將股票用具體的數值來表示。
  13. On the base of researching the theory of the scheme and analyzing the signal feature, it is obtained that the existence manners and character of distance information in the differential frequency signal. at the same time, a new conclusion is gained that the technology of frequency agility can decrease the constant error of system. it is also to say that frequency agility and frequency modulation fixed - distance fuze has the similar feature to random period frequency modulation fixed - distance fuze. according to the theory of address coding in the hopping - frequency communication, the paper presents the principle of selecting the frequency agility sequence which fit to the radio fuze and constructs the frequency agility sequence family based on the rs codes

    在深入研究方案原理和分析信號特徵的基礎上,獲得了該體制引信差頻信號中,距離信息的存在形式和特點,得出了頻捷變技術的引入降低了系統定距固定誤差這一新的結論,即頻捷變調頻定距引信在定距性能上具有類似隨機周期調頻定距的特徵。本文引入跳頻通信地址編碼理論,結合無線電引信的具體特徵,提出了適用於無線電引信的頻捷變序列的原則,並構造了基於rs碼的寬間隔頻捷變序列族。
  14. The initial vsd process uses two main characters, the average instantaneous energy and the average instantaneous zero crossing rate ( zcr ). to make the first recognition for the start and the end, the emphasis of which is to select the appropriate value of the threshold and the length of frame. in the final vsd process, the author compares several characters and confirms the new recognition character

    初步分段過程使用了能量和過零這兩個主要特徵進行端點檢測,重點是合理兩個重要參數? ?門限和統計幀長度的取值;在最終分段過程中,筆者首先通過比較幾種特徵的識別效果,卡爾曼濾波參數作為再次分段的識別特徵,還提出了一種新的識別特徵? ?周期性緩變特徵,使用這兩個特徵分別在子語音段內進行端點檢測。
  15. The method proposed in this thesis do well in solving the problems of multi - damping - ratio - spectra simulation. it is convenient to obtain the pareto optimal solution set of the multi - object question by using implicit parallel genetic algorithms and the method can meet the practical needs for simulating ground motions coinciding with multi - damping - ratio - spectra in seismic design. the crossing rate and variance rate are important parameters of genetic algorithms which affect the rate of convergence, the adapting rate of cross and variation in this paper can auto - adapt and according to stand or fall of current sample, it assures the sample approach to the pareto optimal solution set in fast convergent speed

    較好地解決多阻尼比反應譜擬合問題;本文方法通過一次運行就能獲得一組具有集系特性的地震動,在擬合多阻尼比反應譜的人造地震波集系的模擬方面有傳統方法所不能比擬的優勢,產生的人造波或人造波集系可滿足工程抗震設計需要;在遺傳演算法中,交叉概和變異概是影響收斂速度的重要參數,本文採用的改進自適應交叉概和變異概,可以根據當前樣本的好壞程度來自動地適當的交叉概和變異概,以保證演算法始終以較好的速度向pareto最優解集逼近。
  16. Fourthly, according with the analyzing of flow measurement, we research the main problems needed to be solve in the process of measurement, such as analysis and measurement of the internal resistance, selection of excitation frequency, stable signal datum mark and restraining common mode interference, restraining for serial mode interference and working frequency interference ; transporting and shielding the flow signal, constant current excitation and magnetic field equalizing, flow measuring

    第四,根據對流量測量問題分析的,深入研究了設計過程中需要解決的主要問題。如內阻分析與測量;勵磁頻;穩定信號基準點與抑制共模干擾;串模干擾與工頻干擾抑制;流量信號傳輸與屏蔽;恆流勵磁與磁場補償;流量測量點的等。
  17. These leds light sources are not only adjustment and uniformity but also smaller, less expensive, required less power, generated less heat. especially, the pattern of the construct both aggregate and desegregate in design was to realize different light intensity illumination on same biology sample at the same time. the selectivity, work efficiency and experiment veracity have been improve greatly

    該系列光源除了具備光強可調、分佈均勻優勢外,還具有波長、波峰寬適宜,以及小巧、價廉、能耗低、發熱少等特點,尤其是該生物光源在設計時採用的單元組裝模式,使得不同強度的光照能夠在同一批生物樣品上實現,大大拓寬了生物實驗的可性,提高了工作效和實驗準確性。
  18. Long - hole and geometrical proportion type of mixing unit is finally adapted in lpg supply system, and power and torque output of lpg engine are improved by increasing compression ratio, and ignition characteristic is tried to adjusted to satisfy engine performance. meantime emission performance and noise level of lpg engine at full - throttle and other various part - throttle operations are tested and compared with former gasoline engine. ( 3 ) it is verified by engine dyno tests that lpg engine has better synthesized performance at aspects of power and torque, fuel economy, as well as emission than former gasoline engine

    了等比例長孔式混合器控制空燃比;通過提高壓縮比來彌補動力性的損失;以動力性為主控目標,對最大功點、最大扭矩點、中等轉速、最低轉速點所對應的發動機轉速做了點火特性的調節;通過空燃比的合理控制,直接改善發動機的動力性、經濟和排放指標;作為對缸內燃燒過程的理論分析,進行了燃燒特性的實驗測試;對原汽油機和新開發的液化石油氣發動機,進行了外特性和部分負荷特性以及怠速的排放及噪聲對比性測試。
  19. Electromagnetics simulation of frequency selective surfaces

    表面電磁模擬
  20. After getting the standard difference and beta index of after risks, it gets three measuring figures : shape performance index, treyner performance index and jesen performance index through establishing the after feature line model, and compared them. finally, combining with the present situation of investment fund in china, using the investment fund performance evaluation research at home and abroad as the reference, adopting indexes such shape, treyner, jesen, stock net selection rate and c value, it evaluates the performance of investment funds in china in four aspectsxomprehensive performance measurement of investment funds. stock selection capacity. market opportunity seizing capability and investment portfolio ; and mares a case analysis on the ten representative funds in china

    最後,結合我國的投資基金的具體現狀,借鑒國內外同行對投資基金績效評估的研究,運用夏普業績指數、特雷諾指數、詹森業績指數、股票凈選擇率、 c值等指標,從投資基金的綜合業績度量、股票能力、市場時機把握能力和投資組合分析四個方面對我國投資基金的績效進行了評估,並對在我國投資基金中有代表性的十隻基金進行了實證分析。
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