approximate expansion 中文意思是什麼

approximate expansion 解釋
近似展開式
  • approximate : vt 1 使接近。2 接近；走近。3 近似，約計。4 模擬。5 估計。vi 近於。 His income this year approxima...
  • expansion : n 1 張開，伸展。2 擴大；擴建；展開；發展。3 廣袤，遼闊。4 擴張物，擴大部分。5 （講題等的）詳述，...
  1. By introducing proper stretchy variable and constructing boundary layer function, it concludes n - order approximate solution, and using theory of differential inequality, uniformly validity of asymptotic expansion is proved

    通過引進適當的伸長變量，構造邊界層函數，得到了解的n階近似值，並利用微分不等式理論證明了解的漸近展開式的一致有效性。
  2. The main results achieved in this thesis can be summarized as follows : 1. by means of the fourier series expansion, an approximate analytical propagation equation of flattened gaussian beams ( fgbs ) passing through an apertured paraxial abcd optical system is derived, and illustrated with numerical examples, when the transmissivity of the aperture is t ( x ) = cos ( x )

    用傅立葉級數展開法研究了平頂高斯光束通過有光闌限制的近軸abcd光學系統的傳輸特性，導出了光闌透射率為t （ x ） = cos （ x ）時的近似解析傳輸公式，硬邊光闌的情況可作為= 0的特例得到。
  3. In this paper, we expand eigenvalue of poisson equation using bilinear element, by the formulation of the error expanition, we can conclude that it is a upper bound. and by two numerical example, we computer the approximate eigenvalue of poisson equation in square and l - shape domains, then we analyses the approximate eigenvalue. we also extraplate the error expansion and enhance the accuracy of the eigenvalue form the second order to the forth order

    本論文對poisson方程的特徵值採用雙線性元進行展開，得到了誤差展開式，通過誤差展開式，我們能得到特徵值是上界。通過數值算例，計算方形與l形區域上的poisson方程的近似特徵值，並對數據進行分析，驗證了理論的正確性，然後通過對誤差展開式外推，收斂級數可以從二階提高到四階，得到了高精度的解。
  4. In this paper, dynamic stability of parametrically excited flexible cam - follower system on the weakly nonlinear condition is investigated by using the combination of both the method of multiple scales and the technique of fourier series expansion. the equations of approximate transition curves in the plane of the dimensionless frequency and excitation ( amplitude ) parameter that separate stable from unstable solution are derived

    隨后，本文採用多尺度法並結合fourier級數展開，分析了不同的凸輪從動件運動規律和不同的凸輪的升程、停程以及回程的時間分配規律下，無間隙的周期時變凸輪系統模型的穩定性，獲得了各種規律下的凸輪系統的穩定區間圖。
  5. Quark medium is regarded as non - harmonic oscillator model, discussing its response to su ( 2 ) non - abelia field, the perturlation expansion method is used to find the first, second and third order approximate solutions to the response equation, and some nonlinear features of the response are preliminarily displayed

    將夸克介質視為非簡諧振子模型，討論了它對su （ 2 ）非阿貝爾場的響應，採用微擾迭代法解出了方程的一、二、三級近似解，初步得出了這種響應的一些非線性特徵
  6. This paper, in allusion to damage of expansion joint of bridge, introduces a sort of new structure of jointless device - semi - integral abutment jointless bridge, and establishes model of general structure finite element of this bridge, and in details analyses its qualities of stress. the model considers the interaction of superstructure - substructure - soil. resistance of the soil behind abutment adopts still soil pressure and elastic resistance when the temperature rising, but active soil pressure when dropping. analysis of qualities stress of bridge includes of action of dead load, car load, temperature load of season character. taking an 100m length pc semi - integral abutment jointless bridge as instance, the paper establishes the model of plane frame by applying large common software - anasys, and analyses it by elastane and large deformation to imitate character of stress and deformation of general bridge. at the same time corresponding models of finite element of joint bridge and integral abutment bridge are established, and unique stress and performance of structure of semi - integral abutment jointless bridge are researched by comparing and analysing character of three different models under same loading, and controlling factor of design and constitution are generalized. in conclusion, for semi - integral abutment jointless bridge, on one hand shear, moment and deflection of the main beam and axis force of substructure are approximate with that of joint bridge, and integral stifmess of structure is increased and damage of expansion joint is eliminated, on the other hand there is axis force in main beam, shear and moment of substructure are bigger than that of joint bridge. in all this type of jointless bridge has rational stress and is worth of application and popularization

    半整體式橋臺無縫橋梁計算模型考慮了上部結構-下部結構-土的共同作用；臺後土抗力升溫時採用靜止土壓力加彈性土抗力，降溫時採用主動土壓力；分析橋梁受力性能時考慮了結構自重、車輛荷載和季節性溫變荷載的作用。以一座橋長100mpc半整體式橋臺無縫橋梁為實例，採用大型通用軟體ansys建立平面框架模型，進行彈性、大變形分析，模擬全橋受力和變形特點；同時建立與此對應的有伸縮縫橋梁和整體式橋臺無縫橋梁有限元模型，通過三種橋型同步加載對比分析，研究半整體式橋臺無縫橋梁獨特的受力特點和結構性能，總結其設計控制因素和構造要求。通過本文研究知：半整體式橋臺無縫橋梁主梁的剪力、彎矩、撓度和下部結構的軸力與梁式橋相近，結構整體剛度增大，併除去了伸縮縫病害；但主梁增加了軸力，下部結構剪力、彎矩較梁式橋大；綜合分析是一種受力合理有實踐和推廣價值的橋型。
  7. And beginning with a perturbed nls equation, using a multi - scales perturbation expansion, we get the zero order and the first order equations, discuss the eigenstates of the operator in the equations, induct relevant " derivative states ", form the completeness of the bounded eigenstates of the associated operator in li space, and expand the corresponding parameters in the closure, get a series evolution equations of the coefficients in the expanded formulas, find the first order approximate solution by researching the evolution equations. this paper also gives the basis of this method - the completeness we have formed and the singular perturbation technique

    ） dinser方程的求解問題，討論了自伴運算元的本徵函數的正交性和完備性，介紹了尋求微分方程的近似解常用的攝動方法，並從帶有某種擾動項的nls方程出發，利用多重尺度的攝動方法得到了方程的零級近似方程和一級近似方程，通過對近似方程中運算元的特徵態的討論，引入適當的「導出態」 ，建立了運算元在l _ 2空間的特徵態的完備性。
  8. From the exact expression of the field, we obtain a multipole polynomial expansion, and under the paraxial condition we furthermore obtain the approximate expression. the loffe trap, consisting of two coils with parallel currents and four straight conductors with currents in alternating directions, is one of the most important traps. we specially study the field structure of it by using both the exact expression and a multipole polynomial expansion that facilitates studies of classical or quantum orbits. if the region near the origin is of interest, we may obtain a simple expression of the field and this configuration may be called idealized loffe trap

    若只討論阱中的近原點區域時，阱中的磁場可以呈現出一種簡潔的形式，人們把它稱為理想ioffe阱。磁矩反平行於磁場的中性粒子在阱中與磁場發生相互作用，藉助相互作用勢，可以獲得粒子在阱中的經典運動方程。在一定的近似條件下，我們可以採用逐次近似的方法，使方程簡化，其中三個分量式中關于z的方程比較容易求解，而關于x 、 y的方程則演化為我們熟悉的馬丟方程的形式。
  9. The innovations of this thesis are as the follows : 1 ) it is analyzed that the lower - order jacobi - anger expansion model for an incoherently distributed source has better accuracy performance than some other approximate source models such as space frequency model, two - point source model, and low - rank approximate model. using the parametric decoupling property of the ja - based model, a novel angular parameter estimator is proposed, which is very robust in case of large angular spreading

    本文從這三個方面開展了空間分佈源波達方向估計研究，創新點包括： 1 ）分析了低階jacobi - anger級數展開近似模型的誤差性能；利用該近似模型的參數解耦特性，提出了一種新的波達方向估計器，在大角度擴展條件下，該估計器表現非常穩健。
  10. In connection with the researches carried out in our laboratory, the description is concentrated on the high accurate four - component relativistic density functional methods with relativistic effects taken into account strictly, and the two - component or scalar relativistic density functional methods with relativistic effects considered approximately, involving the zero - order regular approximation ( zora ) method and its improved variants, the singularity excluded approximate expansion ( seax ) method, and the jointed two component - scalar relativistic ( or non - relativistic ) approach applicable to the calculations of large systems locally containing heavy elements

    結合本實驗室的研究工作，重點介紹嚴格處理相對論效應的四分量相對論密度泛函計算方法和近似處理相對論效應的兩分量和標量相對論密度泛函計算方法，包括零級規則展開近似（ zora ）方法及其改進和排除奇點的近似展開（ seax ）方法，以及適合處理局部包含重元素大體系的接合兩分量標量相對論（或非相對論）計算方法。
  11. Control systems in modern automatic engineering are nonlinear, time - changed and indefinite. lt is difficult to model by traditional method, even sometime impossible. under these circumstances we should apply model identification to gain the approximate model of object for effective control, there are many models to be chosen, fuzzy model is one of them, it is put forward with the development of fuzzy control. fuzzy model has characteristics of general approximation and strong nonlinear, it is fit for describing complex, nonlinear systems. to avoid rules expansion when the number of input values are very big. in this paper we apply hierarchical fuzzy model to resolve this problem, we also illustrate it has general approximation to any nonlinear systems. genetic algorithm is a algorithm to help find the best parameters of process. lt has abilities of global optimizing and implicit parallel, it can be generally used for all applications. in our paper we use fuzzy model as predictive model and apply ga to identify fuzzy model ( including hierarchical fuzzy model ), we made experiments to nonlinear predictive systems and got very good results. the paper contains chapters as below : chapter 1 preface

    現代控制工程中的系統多表現為非線性、時變和不確定性，採用傳統的建模方法比較困難，或者根本無法實現，在這種情況下，要實現有效的控制，必須採用模型辨識的方法來獲取對象的近似模型，並加以控制，目前用於系統辨識的模型種類很多，模糊模型是其中的一種，它隨著模糊控制的發展而被人提出，模糊模型具有萬能逼近和強非線性的特點，比較適合於描述復雜非線性系統，為了解決模糊模型在輸入變量較多時規則數膨脹的問題，文中引入遞階型模糊模型，並引證這種結構的通用逼近特性。遺傳演算法是模擬自然界生物進化「優勝劣汰」原理的一種參數尋優演算法，它具有隱含并行性和全局最優化的能力，並且對尋優對象的要求比較低，在工程應用和科學研究中，得到了廣泛的應用，本文將遺傳演算法引入模糊模型的辨識，取得了很好的效果。
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