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101.
A subdivision collocation method for solving two point boundary value problems of order three 下载免费PDF全文
In this paper, we propose a method for the numerical solution of self adjoint singularly perturbed third order boundary value problems in which the highest order derivative is multiplied by a small parameter $\varepsilon$. In this method, first we introduce the derivatives of two scale relations satisfied by the subdivision schemes. After that we use these derivatives to construct the subdivision collocation method for the numerical solution of singularly perturbed boundary value problems. Convergence of the subdivision collocation method is also discussed. Numerical examples are presented to illustrate the proposed method. 相似文献
102.
Di-Rong Chen 《Journal of Approximation Theory》1999,97(2):685
Subdivision operators play an important role in wavelet analysis. This paper studies the algebraic properties of subdivision operators with matrix mask, especially their action on polynomial sequences and on some of their invariant subspaces. As an application, we characterize, under a mild condition, the approximation order provided by refinable vectors in terms of the eigenvalues and eigenvectors of polynomial sequences of the associated subdivision operator. Moreover, some necessary conditions, in terms of nondegeneracy and simplicity of eigenvalues of a matrix related to the subdivision operator for the refinable vector to be smooth are given. The main results are new even in the scalar case 相似文献
103.
为了抑制杂散条纹的影响,提出了一种简单实用的单幅三表面干涉条纹傅里叶分析法,它根据三表面干涉时各个表面干涉的条纹调制度不同,从三表面干涉图的频谱中提取测试面的频谱,从而准确地恢复测试面的面形。模拟结果证明了该方法的有效性,准确度可以达到l/1 000。实验表明:单幅三表面干涉条纹傅里叶分析法得到的面形形状与波长调谐时域傅里叶变化法和涂消光漆法得到的结果基本一致,PV值和RMS值与波长调谐时域傅里叶变化法相差分别为0.001l和0.004l,与涂消光漆法相差分别为0.042l和0.019l。通过7次单幅三表面干涉条纹傅里叶分析法测量,得到PV和RMS值的重复性分别为0.007 8l和0.002 6l。 相似文献
104.
一类与BB型对偶剖分相关的广义差分格式 总被引:1,自引:1,他引:0
豆引言考虑二阶椭圆方程的边值问题〔,a.an.a.&t-。^D一[六(a于)十十…于)」一八x,y),(x,y)En,(1.1)J“山一而“av”-av”。。、一、。。,\一·。·---,l。。、____(.2)LU一0,(J,y)E厂一go,其中D是多边形区域,厂一JD为0的边界,f(x,y)为o上的已知函数/三L‘(0),系数a—a(xJ)充分光滑,且存在常数7>O,使得以X,y)>/,对任意(X,y)ED.文[1],[2]已系统地研究了求解口.1),(l.2)的广义差分法.广义差分法的基本思想是对求解区域0作三角形剖分TA及其对偶剖分T;,然后构造T^上的试探函数空间U。(有限元空间)和耳上的… 相似文献
105.
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107.
The Maker fringes technique is commonly used for the determination of nonlinear optical coefficients. In this article, we present a new formulation of Maker fringes in parallel-surface samples, using boundary conditions taking into account the anisotropy of the crystal, the refractive-index dispersion, and the reflections of the fundamental and the second harmonic waves inside the material. Complete expressions for the generated second harmonic intensity are given for birefringent crystals for the case of no pump depletion. A comparison between theory and experimental results is made, showing the accuracy of our theoretical expressions. 相似文献
108.
A simple technique is given for measuring stresses in reflecting thin films, using real-time holography. The technique gives clear real fringes with good visibility which can be easily monitored and photographed. No substrate profile measurement is needed. Thermal stress of 0.49 × 109 dynes cm-2 is observed for a 200.0 nm thick Ag film in the temperature range of 30 to 55°C. This is in good agreement with reported values. 相似文献
109.
Carlos Prez Lpez Fernando Mendoza Santoyo Ramn Rodríguez Vera Marcelo Funes-Gallanzi 《Optics and Lasers in Engineering》2002,38(3-4)
In industrial and other types of non-controlled environments, an unbalanced rotating object may present characteristic out-of-plane vibration amplitude at a specific frequency. For this type of cases and as a first step towards a complete evaluation, it is only desired to visualize the effect of the vibration on the rotating object, or vice versa, for instance to achieve object balancing. Real time optical non-intrusive measurement techniques such as pulsed electronic speckle pattern interferometry (ESPI), are well suited to study this rotating-vibrating object. The advantage offered by ESPI is that real-time fringe data is qualitatively analyzed while being observed on a TV monitor. The present paper proposes a qualitative method, based on pulsed ESPI, to separate rotation fringes from fringes solely related to vibration. The method relies on a high precision scheme that synchronizes and fixes an object point during rotation, without the use of an optomechanical object derotator. 相似文献
110.
Peter Oswald 《Advances in Computational Mathematics》2004,20(4):401-423
We give a refined analysis of the Hölder regularity for the limit functions arising from a nonlinear pyramid algorithm for robust removal of non-Gaussian noise proposed by Donoho and Yu [6,7,17]. The synthesis part of this algorithm can be interpreted as a nonlinear triadic subdivision scheme where new points are inserted based on local quadratic polynomial median interpolation and imputation. We introduce the analogon of the Donoho–Yu scheme for dyadic refinement, and show that its limit functions are in C
for >log4(128/31)=1.0229.... In the triadic case, we improve the lower bound of >log2(135/121)=0.0997... previously obtained in [6] to >log3(135/53)=0.8510.... These lower bounds are relatively close to the anticipated upper bounds of log2(16/7)=1.1982... in the dyadic, respectivly 1 in the triadic cases, and have been obtained by deriving recursive inequalities for the norm of second rather than first order differences of the sequences arising in the subdivision process. 相似文献