有限差近似 的英文怎麼說

中文拼音 [yǒuxiànchājìn]
有限差近似 英文
finite-difference approximation
  • : 有副詞[書面語] (表示整數之外再加零數): 30 有 5 thirty-five; 10 有 5年 fifteen years
  • : Ⅰ名詞(指定的范圍; 限度) limit; bounds Ⅱ動詞(指定范圍, 不許超過) set a limit; limit; restrict
  • : 差Ⅰ名詞1 (不相同; 不相合) difference; dissimilarity 2 (差錯) mistake 3 [數學] (差數) differ...
  • : Ⅰ形容詞1 (空間或時間距離短) near; close 2 (接近) approaching; approximately; close to 3 (親...
  • 有限 : limited; restricted; finite; a little; not much
  • 近似 : approximate; similar; approach; approximation; roughness; propinquity
  1. Finite element method ( fem ) is an approximate solution in engineering, there exists some error in the analysis result, so it is important to check the result and to geta right view of the result in the analyzing process, then this can lead the right analysis in the next step

    摘要元法是一種工程求解的方法,存在誤,所以在用元軟體進行工程分析計算時,很重要的一點是分析過程中必須審視分析的結果,對結果正確的認識,從而指導工程分析的正確進行。
  2. In the thesis, the fundamental formula of ffd method derives from the square root that is approximated by a continued fraction expansion in the one - way wave equation. optimizations of the parameters of the finite - difference operator improve the validity of the method

    本論文用連分式單程波波動方程中的平方根導出ffd演算法的基本公式,並對ffd演算法中的分運算元進行了系數優化,進一步提高了計算的效性。
  3. The novel three - dimensional finite - difference approximations of mur ' s absorbing boundary conditions are also presented in frequency - domain. then the ddm based on fdfd is investigated in the applications of three - dimensional electromagnetics problems. and it is used to analyze the leaky wave antenna based on image nonradiative dielectric ( nrd ) guide

    最後,闡述了maxwell方程組和劃分區域的despres傳輸條件的頻域分格式建立,在截斷邊界上構造了三維頻域mur條件的,探討了基於頻域分的區域分解法在三維電磁問題中的應用實現,並將該演算法用於分析一種基於nrd波導結構的漏波天線。
  4. Finally, we establish rational spectral formation of discrete with regard to time and space, and gained the error estimate in the finite - time in the abstract

    最後,我們構造了同時關于時間空間方向離散的譜格式,並從理論上建立了在時間上的全離散格式解的誤估計。
  5. In order to predict hydrodynamic characteristics a computational system is developed including determination of the pressure distribution on a wing section by use of the conformal mapping method and panel method respectively and of the flow in boundary layer according to the thin shear layer approximation ( tsl ) for navier - stokes equation approach. the wing sections of naca4412 and naca0012 are applied to test the computational system. the numerical inspection shows that the panel method with better precision and the momentum and the displacement thickness of boundary layer can be used to complete this calculation

    本文分別用守屋的保角變換法和基於源匯渦分佈的面元法,建立了計算槳葉表面壓力分佈的數學模型;應用納維-斯托克方程的薄層理論模式和分數值方法,建立了計算機翼表面邊界層內部流動的數學模型;應用槳葉表面邊界層內部粘性流動和外部勢流流動在邊界上的匹配演算法,建立了槳葉表面二相流流動的計算方法和相應的計算機程序。
  6. In chapter two, we consider the finite volume element methods for nonlinear parabolic problems optimal order error estimates in the h1, l2norms and w1, almost optimal error estimates in l are demonstrated. moreover superconvergence in the error between the approximate solution and the generalized elliptic projection of the exact solution is also shown

    第二章考慮非線性拋物方程的初值問題的體積元法,並證明了h ~ 1 , l _ 2和w ~ ( 1 , )誤估計以及l _最優誤估計,而且還得到了解和真解的廣義橢圓投影間的超收斂估計。
  7. By detailed theoretical analyses, optimal order in h ^ 1 - error estimates is obtained between the exact solution of original problem and the solution of these fully discrete schemes

    給出了全離散特徵體積元格式,並通過詳細的理論分析,得到了解與原問題真解的最優h ^ 1模誤估計。
  8. Finite difference approximate solutions for the

    方程的
  9. Using the approximation form of lumped mass matrix instead of the mass matrix in finite element discretization in space, backward differencing scheme in time, an implicit computational scheme is yielded, it proved the convergence estimate for this implicit scheme

    元離散中引起較大誤的質量矩陣,採用了形式的集總質量矩陣來代替,時間項採用向後分,得到了一個隱式的計算格式,證明了計算格式的收斂性及其收斂速度估計。
  10. Author, secondly, starts from the approximate expandness of square root operator, perform mathematical calculations for finite difference operator in frequency - space domain, fourier finite difference operator in mixing domain ( frequency - space and frequency - wavenumber domain ) and general screen operator in mixing domain, compare and discuss their precision of their wavefield, adaptability for lateral velocity variations, computation efficiency and stability. thirdly, author, applies the steady variational reference slowness rytov approximation general screen wavefield extrapolation operator ( vrselrf ) in frequency - wavenumber domain, to the prestack and poststack forward modeling and depth migration

    第二,從平方根運算元的展開出發對頻率?空間域的分運算元、混合域(頻率?空間域;頻率?波數域)的fourier分運算元、混合域的廣義屏運算元進行了推導並對其波場描述精度、對橫向變速的適應性、計算效率和穩定性進行了比較與評述。
  11. Two - order enhanced un - split finite volume euler method for multi - fluid flow, which combines the roe approximate riemann solver, is developed to simulate the multi - fluid interactions, such as the fluid described by polynomial eos, stiffen gas eos, jones - wilkins - lee ( jwl ) gaseous explosive eos, cochran - chan ( cc ) solid explosive eos and hom shock wave eos, etc. numerical results of the id, 2d and 3d multi - fluid interaction examples show that the high - resolution method and interface capturing equations can resolve the multi - fluid flow correctly and successfully. a simple fluid - mixture type ppm algorithm for multi - fluid flow, which is based on vof interface capturing method and resolved by langange / remap two steps, is developed to simulate the high density or high pressure ratio flow at both sides of the interface

    本文提出了實用於多介質流體的增強型二階精度體積歐拉數值計算方法,採用roe方法求解riemann問題,可以適用於多項式狀態方程、 「 stiffengas 」狀態方程、 jones - wilkins - lee爆轟產物狀態方程、 cochran - chan固體炸藥狀態方程以及hom狀態方程等,並對多介質流體相互作用的一維、二維、三維問題進行數值計算,數值驗證了本文給出的高精度分格式和界面捕捉方法的正確性,兩種方法耦合形成的多介質流體數值計算方法是成功的。
  12. This feature reflects the physical phenomenon of breaking of waves and development of shock waves. in the fields of fulid dynamics, ( 0. 2. 1 ) is an approximation of small visvosity phenomenon. if viscosity ( or the diffusion term, two derivatives ) are added to ( 0. 2. 1 ), it can be researched in the classical way which say that the solutions become very smooth immediately even for coarse inital data because of the diffusion of viscosity. a natural idea ( method of regularity ) is obtained as follows : solutions of the viscous convection - diffusion pr oblem approachs to the solutions of ( 0. 2. 1 ) when the viscosity goes to zeros. another method is numerical method such as difference methods, finite element method, spectrum method or finite volume method etc. numerical solutions which is constructed from the numerical scheme approximate to the solutions of the hyperbolic con - ervation laws ( 0. 2. 1 ) as the discretation parameter goes to zero. the aim of these two methods is to construct approximate solutions and then to conside the stability of approximate so - lutions ( i, e. the upper bound of approximate solutions in the suitable norms, especally for that independent of the approximate parameters ). using the compactness framework ( such as bv compactness, l1 compactness and compensated compactness etc ) and the fact that the truncation is small, the approximate function consquence approch to a function which is exactly the solutions of ( 0. 2. 1 ) in some sense of definiton

    當考慮粘性后,即在數學上反映為( 0 . 1 . 1 )中多了擴散項(二階導數項) ,即使很粗糙的初始數據,解在瞬間內變的很光滑,這由於流體的粘性擴散引起,這種對流-擴散問題可用古典的微分方程來研究。自然的想法就是當粘性趨于零時,帶粘性的對流-擴散問題的解在某意義下趨于無粘性問題( 0 . 1 . 1 )的解,這就是正則化方法。另一辦法從離散(數值)角度上研究僅對流項的守恆律( 0 . 1 . 1 ) ,如構造它的分格式,甚至更一般的體積格式,元及譜方法等,從這些格式構造解(常表現為分片多項式)來逼原守恆律的解。
  13. A stable finite difference approximation for vibration equation of beams

    梁振動方程的一個穩定的
  14. First, we simply introduced the optical wave - guide theory : the fluctuation equations of planar wave - guide and the preparation of embranchment wave - guide. then based on maxwell equations and in the paraxial limit we deduced the formula needed in calculating fd - bpm. the refractive index section was n ( x, y )

    然後我們在maxwell方程的基礎上,根據慢包絡理論,在折射率截面為n ( x , z )的條件下,利用來代替偏微分方程,推出了分光束傳播法計算所需要的公式。
  15. The full potential equation is solved by the time - accurate approximate factorization algorithm and internal newton iterations, and the euler equation by the finite - volume resolution scheme and dual - time stepping

    對全位勢方程採用精確隱式因式分解分格式、牛頓內迭代演算法。對euler方程採用體積法和雙時間推進。
  16. Currently, the calculating theories of concrete - beam temperature fields can be divided summarily into three types : category 1 is the method of how the hot conduct in the square distance ; category 2 is the proximate - number analytical method, such as finite difference method, finite element method etc. ; category 3 is a half experience and half theoretic method

    目前混凝土箱梁溫度場的計算理論和方法概括起來,大致可以分為三類:第一類為熱傳導方程求解法;第二類為數值分析方法,如分法、元法等;第三類為半經驗半理論法。
  17. Two interactive segmentation methods, snake ( active contour ) and live wire, which are very popular, have been introduced for the medical image segmentation. a snake is a spline curve, which is controlled by an energy equation. to minimize the snake ' s total energy, the finite difference and greedy algorithm have been implemented

    論文引入了snake和livewire兩種十分流行的醫學圖像交互分割方法,詳細推導snake的能量方程,實現了最小化能量方程的分和greedy兩種演算法,並利用鄰圖像的相性,將其成功應用於圖像序列的分割; livewire是一種象素級的輪廓搜索演算法,它在方向圖中找到開始點和目標點之間的最小代價路徑。
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