指向性系數 的英文怎麼說
中文拼音 [zhǐxiàngxìngxìshǔ]
指向性系數
英文
directivity factor-
Plant endemism is the key problem in floristic study. analysis of endemism in a flora has significant implications in demonstrating floristic richness and diversity, the relationship between plants and their environment, and also in conserving biodiversity of the flora. in view of the situation that most of the past studies on endemism were qualitative, this study is the first tentative approach to the introduction of quantitative indices to the analysis of floristic endemism, with an purpose to push the study of endemism from qualitative to quantitative. four quantitative indices are introduced, i. e. level of endemism ( l ), coefficient of endemism ( c ), degree of endemism ( d ) and general index of endemism ( a ). mathematical formulae have been given to each of the above indices and explanations for them have been presented, and the scope of their use in floristic studies has been delimited and exemplified in this paper. the result shows that they are of good applicability. the proposed indices embody full information of plant systematics and plant geography. with the aid of qualitative analysis, the application of the proposed indices will improve the comparability and precision of endemism study in floristics
過去有關特有現象的研究主要限於定性的分析,可比性和精確性較差.該文嘗試引入特有現象的定量化指標,以推動特有現象的分析研究從定性水平向定量水平邁進.所引入的4種定量化指標分別是:特有水平、特有系數、特有度以及特有綜合指數.對每種量化指標都給出了數學表達式,說明了其區系學意義,例證和界定了這些指標在植物區系分析中的應用,結果表明,它們有良好的適用性.這些指標充分地包含了植物系統學和植物區系學的信息.結合定性分析,這些指標的應用將增強植物區系研究的可比性,使植物區系特有現象的分析達到更精確的水平The antenna gain, directivity and reflection coefficient are calculated via finite element method in hfss. spline interpolation and polynomial curve fitting are applied to construct diagrams illustrating the capsulation characteristics. some general conclusions of interest are obtained
探討了各個封裝參數對輸入端反射系數、方向性系數、效率和增益等性能指標的影響,得到一些規律性結論,為射頻振子天線的封裝應用提供了參考性的建議,並指出了進一步研究的方向。The software ansys6. 0 is used to analysis the stability of the state after construction of tongwamen bridge, linear method is used in analyzing the finite element model of the bridge, the coeffient of stability of different state after construction is given. on the basis, the effect of different factors such as the arrangement of lateral brace, the sloping angle of arch ribs, the stiffness of bridge deck system, the effect of non - orientedly conservative loadings of the hanger and tie bar etc is discussed. the different coefficients of stability of changing these factors are given, so the factors that are vital to the lateral stability of x - type arches are found, and the rationality of the methods taken to enhance the lateral stability of tongwamen bridge is evaluated
本文應用有限元分析商業軟體ansys6 . 0 ,採用線彈性方法,通過對該橋的空間有限元模型進行穩定性分析,得出其成橋運營階段各種工況下的穩定安全系數。在此基礎上,本文還通過有限元模型分析,就拱的矢跨比、吊桿(立柱)的非保向力效應、橋面系的剛度、橫撐布置形式、拱肋側傾角等因素對該橋整體穩定性的影響展開探討與研究。文中給出了各因素變化情況下的穩定安全系數,指出了對鋼管混凝土提籃拱橫向穩定性有顯著影響的因素及其合理變化范圍,並對銅瓦門大橋提高橫向穩定性的措施的經濟合理性進行了分析。On the base of above it, this paper discuss the synthesis of optimum distributed arrays by nonuniform spacing in the sense of dolph - chebyshev. having derived the equations of optimum element distribution, we analyze the exponentially spaced array, which are optimum when the elements are isotropic and equally weighted, and the array by general raised cosine function. the formulate for estimating the sidelobe envelope, beamwidth of the array pattern and clean region width are obtained
推導了最佳陣元分佈方程,分別對陣元無方向性和等加權時的最佳分散式陣列? ?指數間隔陣列和採用廣義升餘弦加權的最佳分散式陣列進行了分析,推導了天線方向圖旁瓣包絡、波束寬度,干凈掃描區寬度的估計公式,給出了近軸旁瓣電平與陣列參數的關系。Mean, stddev, heterogeneity coefficient and fraction dimension are the indices for evaluating the scaling method in object - oriented image analysis. the change trend of these indices corresponding to segmentation scales is used to judge the validity. in this thesis, object - oriented image analysis is introduced fully
6 .提出可以用影像對象的均值、標準差、異質性系數與分形維數作為評價面向對象尺度轉換的指標,根據這四個指標隨尺度的變化趨勢分析尺度轉換方法的合理性。A niched - penalty approach is used to transform this optimal kinematical design problem to an unconstrained one. a kinematic accuracy comparison of the genetic designed fine - tuning stewart platform with the quasi - newtonian designed one is made. the comparison results have shown that the kinematic accuracy of the genetic designed fine - tuning stewart platform has a much higher accuracy and a compact structure than that of the quasi - newtonian designed one, which guarantees the accomplishment of high precision trajectory tracking and reduces the disturbance of wind to the feed - supporting system
以並聯機器人jacobian矩陣的條件數為優化設計的目標函數,提出了基於遺傳演算法的並聯機器人最優運動學性能結構參數優化設計方法,採用實值遺傳演算法,對精調stewart平臺進行了優化設計,得到了最優運動學的精調stewart平臺結構參數,為實現新一代大射電望遠鏡饋源指向跟蹤系統高精度軌跡跟蹤控制奠定了堅實的基礎。Based on a general overview of firm performance assessment theories, this study makes a comparison between traditional performance measures and strategy - oriented performance measures, analyzes the existing performance measurement system of the national aviation oil companies. the thesis has a literature review of the balanced scorecard researches and applications, expounds the advantages of the balanced scorecard over traditional measurement systems in revealing the intension of firm performance, analyzing the critical factors behind firm performance and providing information support for firm strategy, documents the relationship between the balanced scorecard and firm strategy, and puts forward the idea of strategic performance. by using the data and background information from one of those national monopoly oil companies, this study a ppraises the limits of this sort of companies " performance measurement system, applies balanced scorecard method to this kind of national monopoly oil company, designs questionnaires to collect experts " opinions, colligates the opinions, selects kpis, builds experimentally the first strategy performance assessment indicator system in this kind of company, determines the indicators " parameters, uses the real corresponding data to measure the 6 business lines of this company, through comparing the assessment result with the strategic standard, a conclusion is drawn and suggestions are put forward about how to exploit the performance potential under present conditions
在對績效測評理論進行回顧的基礎上,本文研究了傳統測評指標體系與戰略導向的測評指標體系的區別,總結了中國航空油品經營企業的績效測評現狀,對平衡計分卡理論研究和應用進行了綜述,分析了平衡計分卡在揭示績效內涵和影響績效的因素、發揮績效測評的信息作用等方面的優勢,論述了平衡計分卡與企業戰略的關系,提出了戰略績效的概念,並結合某壟斷性油品經營國有企業的實際,評述了此類企業傳統績效測評指標的局限性,借鑒平衡計分卡思路,通過設計調查問卷、收集專家意見並加以綜合分析等工作,選取關鍵績效指標,探索性地建立了中國壟斷性航油經營國企的首個企業戰略績效測評指標體系,並確定了指標有關參數,對應指標的統計口徑採用經調查獲得的測評所需數據,對該企業6個業務板塊的績效進行測評,通過對比分析得出在現有條件下如何挖掘潛力的結論和建議。On the basis of the study of the theory and appraise method on land use in the small towns from home and abroad, this paper at first conducts a deep study on the development and role of the small towns, indicating that its development has sawn an uneven development phrase and becomes a carrier of the enterprises, a pool of surplus laborers, a hub of material exchanges between the rural and urban areas, a base of spiritual civilization, an important way to achieve urbanization. second, it conducts a study on the situation and features and the problems the land use, indicating that the efficiency of the land use is low, which has a direct influence on the development of agriculture and the role of the small towns. and the study of the demand of the land indicates the shortage of land is serious, and the small town must rationally use the land and increases its intensive role and the economical efficiency to meet the demand
在分析國內外已有關于小城鎮土地利用的理論與評價方法的基礎上,首先對小城鎮在我國的發展、地位和作用進行了深入的分析,判明我國小城鎮發展經歷了一個曲折向上的發展階段,已成為鄉鎮企業的載體,農村剩餘勞動力的蓄水池,城鄉物資交流的樞紐,農村精神文明的基地,是我國城市化的重要途徑;其次,對小城鎮土地資源利用現狀和特徵進行了探討,並對發展小城鎮建設導致的土地利用問題進行了剖析,表明目前我國大多數小城鎮土地效益和規模效益低下,佔用耕地過多,直接影響農業的發展,影響小城鎮的地位和作用;通過小城鎮土地供需分析研究表明,我國土地短缺十分嚴峻,小城鎮土地需求缺口較大,小城鎮必須合理利用現有土地,增強集約功能和土地經濟效益,從而緩解需求壓力;最後,論文通過運用特爾菲法,描述統計分析法、多元統計分析(主成分分析)法和系統分析法中的層次分析法( ahp )等一系列方法,結合定性和定量兩方面,從土地質量、土地資源數量與結構、土地經濟效益、環境效益、社會效益等五個方面進行分析,篩選、建立了土地資源利用評價指標體系,在因子評價的基礎上,建立了土地利用綜合評價模型,並給出了評價過程和方法。In many performance check, artillery control systematic dynamic trail aimed error is one of relatively important parameter, dynamic trail aimed error denote : when high cannon system is dynamic trailing, set bullet pellet flight time is 0, in the condition of not considering advance quantity ( 0 fly working ), the axis of artillery pipe should direct goal
在諸多的性能考核中,火控系統的動態跟蹤瞄準誤差是較為重要的參數之一。所謂動態跟蹤瞄準誤差是指:當高炮系統在進行動態跟蹤時,設定彈丸飛行時間為零,即在不帶提前量的條件下(即零飛工作方式下) ,火炮身管的軸線應直接指向目標。From the point of view of risk, a index system of risk assessment of winter wheat losses caused by drought was established, including the meanings, token models and estimate methods of risk index of natural water deficiency rate, risk index of yield reduction rate and trending vector coefficient of disaster resistance capability, then on the base of these indices, the comprehensive risk index model of losses caused by drought was established and regionalized. the results indicated : the high risk region included the middle north of shanxi, some of middle of shaanxi and some of hebei in east ; the higher risk region included some of middle of shaanxi, the tangshan region and some of west of hebei ; the moderate risk region included the middle of s
從風險的角度,建立了冬小麥乾旱災損風險評估的指標體系,包括自然水分虧缺率風險指數、減產率風險指數和抗災性能趨勢向量系數的意義、表徵模式和估算技術方法,在此基礎上構建了災損綜合風險模型,並對模型參數區域化,結果表明:冬小麥乾旱災損高風險區在陜西中北部、山西中部的部分地區和河北滄州的部分地區;較高風險區在山西中部的部分地區、河北的唐山地區和西部的部分地區;中風險區在陜西中部、山西南部、河北滄州的大部分地區;低風險區在陜西中南部、河南中北部、北京市、天津市、河北中南部和山東省。Using the dsd models and forward scattering amplitude computed by the least squares fitting method, the specific attenuations at l - 400ghz have been computed and analyzed, the parameters of " power law " relation between specific attenuation and rainfall rate are obtained. the specific attenuations in qingdao, guangzhou and xinxiang are compared with itu - r specific rain attenuation models
利用平均雨滴尺寸分佈和點匹配法計算的雨滴的前向散射數據計算和分析了青島、廣州和新鄉地區1 ? 400ghz特徵雨衰減特性,得到了特徵雨衰減與降雨率的指數關系參數,並與itu - r ( internationaltelecommunicationunion - radiocommunication )特徵雨衰減模式進行了系統的比較研究。So the only way for agricultural development is structural adjustment. under the theory of structure economy growing, the theory duality economy structure and the law of the industry structure evolution mainly, this paper, firstly, analyzes the characteristics of evolution and current situation of hubei province ' s agricultural industry structure including the evolving better, singleness, facing crisis, by stage, lack of power, crop ' s development setting back the evolution, asymmetry - structure between the production value and output, the similar structure with the whole nation and the peripheral provinces, and so on
本研究在結構主義經濟增長理論、產業結構演進規律和二元經濟結構論等經濟學理論的基礎上,首先通過產值比重結構對比、產業結構變動度、產業結構波動度、產業結構相似度和偏離系數等指標和方法,從多方面分析了改革開放以來湖北省農業產業結構演進與現狀特徵:農業產業結構逐步優化,但結構單一,面臨危機;農業產業結構呈階段性演進;農業產業結構演進缺乏動力;種植業成為湖北省農業產業結構優化障礙;農業產值與產量結構不對稱,出現逆向變化;農業產業結構與周邊省份趨同等。After controlling indexes of the heat preservation and controlling indexes of the energy conservation for building envelop ( root and walls ) in indoor heating condition is given, by means of the interrelated principle between windows and walls the controlling indexes of heat preservation and the controlling indexes at energy conservation for building envelop ( windows ) in indoor heating condition can be determined directly
摘要該文在室內採暖條件下圍護結構(墻與屋頂)保溫控制指標已確定的基礎上,依據窗墻相關性原理所導出的同一方向窗的傳熱阻與墻的傳熱阻相關性系數(它隨窗墻面積比不同而變化)可直接求出在同一室內熱環境控制條件下窗的保溫、節能控制指標,使保溫控制與節能控制設計更加科學、簡單。Hereafter being the forecasting to the old age population coefficient, this text has been applied two kinds of regression model, namely univariate linear model and logarithmic model, and thought over three kinds of economic speed of development ( high, middle, low ) in the logarithmic model to forecast the old age population coefficient respectively. finally, by analyzing the forecasted value and the inertia law of population development, the paper points out the lengthening of the population equally expected life span will push forward the aging of population step by step to the advanced age development ; the development trend of the population aging continues to be clear, and just appears a stage characteristic ; furthermore, the population aging speed in rural area will be faster than in the city
此後是對老年人口系數的預測,本文應用了兩種回歸模型,即一元線性回歸模型和對數擬合模型,並在對數擬合模型中考慮了經濟發展速度的高、中、低三種方案,對老年人口系數分別進行預測;最後在分析預測值和人口發展慣性規律基礎上對山東省未來人口老齡化發展趨勢作了較深入分析,指出人口平均預期壽命的不斷延長,將逐步推動人口老齡化向高齡化發展;人口老齡化繼續發展趨勢明顯,且呈現出階段性特徵;農村人口老齡化速度將快于城市。This research project, based on the existing problems in mathematics curriculum evaluation and the conceptions of mathematics curriculum as the guideline, systematically analyzes the basic characteristics of the developmental evaluation, i. e. multi - dimensional, formative, developmental, understanding and inspiring. drawing on the modern mathematics conceptions, multi - intelligence theory and theories of constructivism, this project systemically illustrated the connotation of the developmental evaluation : the key of evaluation is for application ; the goal is multi - dimensional ; the process is context - dependent ; the outcome is to promote the development. in view of the conceptions of developmental evaluation ( i. e. human - centered whole evaluation ; quality - focused overall evaluation ; participation - stressed autonomous evaluation ; future - faced evaluation ; guiding evaluation and inspiring evaluation ), the components of the developmental evaluation model in the new mathematics curriculum is analyzed in details in this project ( i. e. goal system, subject system and object system ) and the core structure of the developmental evaluation is established ( i. e. evaluation indicator system model )
本課題研究以數學課程評價的現存問題為著手點,以數學課程理念為目標指向,系統分析了數學新課程發展性評價的多元性、形成性、發展性、理解性、激勵性等基本特徵;以現代數學觀、多元智力理論、建構主義理論以及成功智力理論為理論背景,系統闡述了數學新課程發展性評價之意蘊?評價核心聚焦應用,評價目標指向多元,評價過程依存情境,評價結果歸依發展;以數學新課程發展性評價理念,即以人為本的全體性評價、注重素質的全面性評價、注重參與的自主性評價、促進完善的引導性評價、不斷進取的激勵性評價、面向未來的期望性評價為航標,深入剖析了數學新課程發展性評價模式的構成成分,即目標系統、主體系統和客體系統,由此構建發展性評價模式的核心圖式?評價指標體系的模式:以數學新課程發展性評價過程為參照,尋求並創設評價準則的設計技術,評價權重的構造技術,評價信息的收集技術,評價結果的分析與處理技術;以數學新課程評價系統內蘊的一般認識論、發生認識論與發展認識論指導評價方法,詳細探討了檔案袋法、表現性評價、自我評價與同伴評定相結合的方法、蘇格拉底式研討評定和測驗法在評價中的應用。First, the basic theory of the competitiveness is analyzed, evaluating indexes which conclude relative and absolute indexes basic on the last literatures are set up. second, because the data are too many and computing time is too long, the competitiveness of science and technology of 30 areas are clustered using fuzzy clustering model, the areas of the whole nation are clustered several kinds and we can draw some conclusions of same kind. evaluating the competitiveness using single model can produce white noise, so combinational models which concluding neural network, fuzzy theory and genetic algorithm are brought forward to evaluate the competitiveness of areas which are in the same kind with fujian province in the test
本文首先分析科技競爭力的基本理論,並根據以往研究科技競爭力文獻,建立包含絕對指標和相對指標的評價科技競爭力評價指標體系,其次,針對評價福建省科技競爭力在全國范圍內的排名情況數據較多,計算時間較長的具體情況,利用模糊神經網路模型對全國30個省市自治區科技競爭力水平進行聚類分析,將科技競爭力水平接近的地區聚為一類,得出科技競爭力水平相近地區情況,而後,針對已有文獻科技競爭力評價只是利用單一模型可能產生噪聲,影響評價結果,並且主觀性較強的缺點,本文將神經網路、模糊數學、遺傳演算法等智能演算法組合,利用組合評價模型對福建省和與福建省同在一類的其它地區的科技競爭力水平進行橫向、縱向評價,得出福建省在全國范圍內的科技競爭力水平排名。The first and second parts of the article discuss about the basic performance evaluating theories and the evolvement of western and chinese performance evaluating system, which makes the basic theory of expressway company performance evaluating system design. the third part analyzes the actuality of the characteristics of expressway and expressway management in sichuan. based on the former three studies, the fourth part advances the thought of establishing expressway company performance evaluating system, especially analyzes the structure and proportion design of expressway company performance evaluating index system
論文的第一、二部分圍繞效績評價的基礎性理論和西方國家、中國的效績評價演進歷程進行論述,它構成了設計高速公路公司效績評價體系的理論基礎;第三部分圍繞高速公路行業的特點和我省高速公路管理的現狀進行分析,指出了建立高速公路公司效績評價體系的必要性和需要考慮的行業特性;第四部分是在前面三部分研究的基礎上,提出建立高速公路公司效績評價體系的思路,重點分析了高速公路公司效績評價指標體系的構成及其權數設計,構建了高速公路公司效績評價體系;每五部分通過對高速公路公司效績評價體系的實際應用,來驗證高速公路公司效績評價體系的實用性和可行性,並提出了今後的發展方向。The flexible retaining structure is another important retaining structure in soft soil. the integrated numerical analysis of this retaining structure ( including the methods and theory of calculating active earth pressure under sorts of conditions as well as the calculating method of horizontal stiffness coefficient of bracing structure and the method of deciding boundary condition etc. ) was gived. the effect of all parameters on the characteristics of retaining structure was discussed using methods of sensitivity - analysis
本文針對目前常用的彈性支點法,給出了完整的數值分析方法,包括各種條件下的墻後土壓力的計算方法和原理、支撐系統(或錨拉系統)水平剛度系數的計算、邊界條件的確定方法等,並以此為基礎採用靈敏度系數分析方法討論了各參數對圍護結構形態的影響,指出土體側向基床比例系數是影響圍護結構變形的最主要的參數。The experiment results of anisotropy of brass h68 mechanicalproperties in ironing are introduced in this paper. it is ironing coefficient to influence anisotropy of mechanical properties
列出了在變薄拉伸過程中形成h68黃銅毛坯的機械性能各向異性的實驗研究結果。指出了主要影響機械性能各向異性變化的是變薄系數。Abstract : the experiment results of anisotropy of brass h68 mechanicalproperties in ironing are introduced in this paper. it is ironing coefficient to influence anisotropy of mechanical properties
文摘:列出了在變薄拉伸過程中形成h68黃銅毛坯的機械性能各向異性的實驗研究結果。指出了主要影響機械性能各向異性變化的是變薄系數。分享友人