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1.
讨论一般的最佳插值问题(k≥3):min∫ba|Dkf|2dt,f满足插值条件f(ti)=yi,i=1,...,n和约束f(k)≥0.该问题可转化为非线性方程组,从而用半光滑牛顿型算法求解,算法具超线性收敛性.然后给出一个由函数的k阶导数计算求得原函数的算法.算例显示了所有算法的有效性.  相似文献   

2.
讨论一般的最佳插值问题(k≥3):min∫a^b|D^kf|^2dt,f满足插值条件f(ti)=yi,i=1,…,n和约束f^(k)≥0.该问题可转化为非线性方程组,从而用半光滑牛顿型算法求解,算法具超线性收敛性。然后给出一个由函数的k阶导数计算求得原函数的算法。算例显示了所有算法的有效性。  相似文献   

3.
对任意自然数k,本文提出了k 1类亏度为k的2k次插值样条。较完整地讨论了它们的存在唯一性及对已知函数的逼近度,并论及了其中几类插值样条所具有的某种交分性质。文[1]、[2]中论及的二、四次插值样条均为本文的特例。最后我们指出了一类插值样条在数值积分中的应用。插值问题的提法及其存在唯一性给定区闻[a,b]上的一个分划Δ:a=x_1相似文献   

4.
证明了当 f∈PWπ时 ,‖s(k)2mf - f(k) ‖ Lp(R) → 0 (m→∞ ,2≤p≤∞ ,k =0 ,1,2 ,… ) ,其中PWπ是经典的Paley Wiener类 ,s2mf是在实Riesz基序列上对 f插值的唯一确定 2m - 1次缓增样条 .同时还证明了当 { f(tj) }∈l2 ,f∈Lp(R) (p≥ 2 ) ,‖s2mf‖2 ≤A一致成立时 ,若limm→∞ ‖f -s2mf‖ p=0 ,则 f∈Bπ ,p,其中Bπ ,p为指数π型整函数在R上的限制与Lp(R)的交  相似文献   

5.
三角插值多项式的线性组合   总被引:1,自引:1,他引:0  
鉴于Lagrange插值多项式并非对任何连续函数都能一致收敛,以x(n)k=2k 1/2n 1π,k=0,l,…,2H作为插值节点,将几个算子进行线性组合,构造了两个新的算子Un(f;x)和Un(f;x),使它们的最高收敛阶要优于算子An(f;x),Bn(f;x),Cn(f;x)。  相似文献   

6.
利用亚纯函数的Nevanlinna值分布理论方法,讨论了fm(f(k))n-φ(z)关于值分布的一个结果,得到了更为一般的结论。设f是复平面上的超越亚纯函数,φ(z)是f的一个不恒等于零的小函数,m,k,n都为正整数。当k≥1,n,m≥2时,fm(f(k))n-φ(z)有无穷多个零点。推广并改进了已有文献中的有关定理。  相似文献   

7.
设F为单位圆盘上的一族亚纯函数,a非零有穷复数,k为任一正整数,若对每一f∈F,f零点的重数≥k 1(k≥2),极点重数≥2,′f和f(k)IM分担值a,则F在单位圆盘上正规。  相似文献   

8.
利用亚纯函数的Nevanlinna值分布理论方法,讨论了fm(f(k))n-(a)(z)关于值分布的一个结果,得到了更为一般的结论.设f是复平面上的超越亚纯函数,(a)(z)是f的一个不恒等于零的小函数,m,k,n都为正整数.当k≥1,n,m≥2时,fm(f(k))n-(a)(z)有无穷多个零点.推广并改进了已有文献中的有关定理.  相似文献   

9.
证明了当f∈PWπ时,‖ s2m^(k)f-f^(k)‖Lp(R)→0(m→∞,2≤p≤∞,k=0,1,2,…)其中PWπ是经典的Paley-Wiener类,s2mf是在实Riesz基序列上对f插值的唯一确定2m-1次缓增样条,同时还证明了当{f(ti)}∈ι2,f∈Lp(R)(p≥2),‖s2mf‖2≤A一致成立时,若lin/m→∞‖f-s2mf‖p=0,则f∈Bπ,p,其中Bπ,p为指数π型整函数R上的限制与 Lp(R)的交。  相似文献   

10.
利用亚纯函数的Nevanlinna值分布理论方法,讨论了fm(f(k))n-φ(z)关于值分布的一个结果,得到了更为一般的结论。设f是复平面上的超越亚纯函数,φ(z)是f的一个不恒等于零的小函数, m,k,n都为正整数。当k≥1,n,m≥2时,fm(f(k))n-φ(z)有无穷多个零点。推广并改进了已有文献中的有关定理。
  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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