关于Bernstein-Durrmeyer-Bzier算子在Orlicz空间内的逼近

在连续函数空间和L_p空间内研究算子逼近方法的基础上,利用一阶DitzianTotik积分模与不等式技巧研究了Bernstein-Durrmeyer-Bzier算子在Orlicz空间内的逼近性质.得到了Bernstein-Durrmeyer-Bezier算子在Orlicz空间内的逼近正定理和逼近等价定理.由于Orlicz空间比连续函数空间和L_p空间都"大",其拓扑结构也比L_p空间复杂得多,所以本文的结果具有一定的拓展意义.     

Lupas-Baskakov型算子在Orlicz空间内逼近的强逆不等式

本文利用Hardy-Littlewood极大函数、光滑模和K-泛函之间的等价关系、N函数的凸性、算子矩量估计及Jensen不等式等工具,研究了由陈文忠定义的LupasBaskakov型算子在Orlicz空间内的逼近性质,给出并证明了该算子在Orlicz空间内逼近的强型逆定理.由于Orlicz空间比连续函数空间和L_p空间涵盖更广泛,其拓扑结构也比L_p空间复杂得多,所以本文的结果具有一定的拓展意义.     

Orlicz空间内一类有理函数逼近的一种Jackson型估计

研究了Orlicz空间内一类有理函数逼近问题.在被逼近函数改变l次符号的条件下,借助Steklov平均函数,利用修正的Jackson核,Hardy-Littlewood极大函数,Cauchy-Schwarz不等式等工具,给出了逼近阶的一种Jackson型估计.考虑到Orlicz空间内拓扑结构的复杂性,本文得到的结果比连续函数空间和L_p空间内同类问题的研究结果具有更广泛的意义.     

Lagrange插值和Hermite插值在Orlicz空间内的逼近

在Orlicz空间内研究问题是函数逼近论研究方向里的重要分支之一.插值逼近问题有着深远的理论意义和广泛的应用前景.本文在连续函数空间和L_p空间内研究插值逼近方法的基础上,研究一种Lagrange线性组合插值算子和Hermite插值算子在Orlicz空间内的逼近问题,利用连续模,Holder等式,Hardy-Littlewood极大函数,给出两类插值的逼近度估计,所得的结果更精确于前人的同类结果.     

三阶Hermite插值算子在Orlicz空间内的加权逼近

研究了修正的加权三阶Hermite插值算子在Orlicz空间的逼近性质,利用加权连续模、HardyLittlewood极大函数、Hlder不等式等工具给出了该插值算子在Orlicz空间内的逼近度估计.     

Orlicz空间内的M\"{u}ntz有理函数的逼近

本文研究了Orlicz空间内M\"{u}ntz有理函数逼近问题, 相比于前人对同类问题的研究, 本文改进了系指数$\{\lambda_{n}\}^\infty_{n=1}$所满足的条件, 利用H\"{o}lder不等式、Hardy-Littlewood极大函数、$K$-泛函、连续模、$N$函数的凸性等技巧, 得到逼近的Jackson型定理. 由于Orlicz空间的拓扑结构比连续函数空间和Lp空间复杂, 所以本文的结果具有一定的拓展意义.     

一类Post-Widder算子的线性组合在Orlicz空间内的逼近

正1引言记L_n(f,x)为Post-Widder算子■,其中■Post-Widder算子是Laplace变换的反演公式,有关Post-Widder算子的研究还比较少,该算子及其线性组合的逼近性质在L_p空间内得到了一些结果,如文献[1],[2],[3]等,但在Orlicz空间内Post-Widder算子的线性组合的逼近问题目前尚未见到有人研究,本文研究了算子L_n(f,x)在Orlicz空间内逼近的正定理,逆定理以及等价定理.     

Orlicz空间内两类插值逼近的Stechkin-Marchaud不等式

论文研究了Lagrange插值和Hermite-Fejer插值在Orlicz空间内的逼近问题,并利用函数逼近论中的常用方法和技巧以及K泛函、连续模、Holder不等式、凸函数的Jensen不等式等工具得到了这两类插值在Orlicz空间内逼近的Stechkin-Marchaud不等式.     

修正的Grünwald插值算子在Orlicz空间内的加权逼近

本文研究了以第一类Chebyshev多项式的零点为插值结点组的一类修正的Grünwald插值算子在Orlicz空间内的加权逼近问题,运用Hardy-Littlewood极大函数,N函数的凸性,K-泛函,连续模以及Jensen不等式等工具,给出了这类插值算子在Orlicz空间内的逼近定理.     

修正的积分型求和算子在Orlicz空间中的逼近（英文）

本文介绍由Φ(x)构成的Orlicz空间L_Φ~*[0,∞),并介绍Orlicz空间的Hardy-Littlewood性质.然后给出Orlicz空间中修正的加权K-泛函与加权连续模的等价定理,最后建立修正的积分型求和算子在Orlicz空间中逼近的正、逆定理和等价定理.从而推广了该算在L_p[0,∞)空间中逼近性质.     

Study of the blow-up of solutions of systems of equations of hydrodynamic type

Mathematical Notes - We study the initial boundary-value problem for three-dimensional systems of equations of pseudoparabolic type. The system is similar to the Oskolkov system, but differs from...     

Distribution of types of symmetry of tensors of high degree

The asymptotic distribution of tensors of degree N in symmetry types is studied in this paper.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 155, pp. 181–186, 1986.     

Characterization of types of asymptotic discernibility of families of hypotheses

We give a characterization of the types of asymptotic discernibility of families of hypotheses in the case of hypothetical measures that are not, in general, mutually absolutely continuous. The case when the logarithm of the likelihood ratio admits an asymptotic expansion of the type of an expansion with local asymptotic normality is examined in detail. Examples are studied.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 64–71, 1987.     

Axiomatizability of reducts of algebras of relations

In this paper, we prove that any subreduct of the class of representable relation algebras whose similarity type includes intersection, relation composition and converse is a non-finitely axiomatizable quasivariety and that its equational theory is not finitely based. We show the same result for subreducts of the class of representable cylindric algebras of dimension at least three whose similarity types include intersection and cylindrifications. A similar result is proved for subreducts of the class of representable sequential algebras. Received October 7, 1998; accepted in final form September 10, 1999.     

Lengths of periods of continued fractions of square roots of integers

Empirical study of the period’s length T of the continued fractions of $\sqrt{Q}$ (for growing integers Q) shows several strange asymptotical results, for instance, $T\leq C\sqrt{Q}\ln{Q}$ . These results show important differences between the statistics of the elements of the continued fractions of random real numbers and of square roots of random integers.