关于亚纯函数理论中与极点无涉的基本不等式

<正> 关于奈望利纳(Nevanlinna)氏第二基本不等式曾有引入纪(导)数而作之种种不同的推广,在这些推广式中,极点的密指量每见出现且有特殊作用,因之能否将此量消去是一问题.米约(Milloux)氏及熊庆来教授由不同途径各获得与极点无涉之一不等式此二结果形状互异而各有特点.熊庆来教授指出这两个结果尚可推广到更普遍的境地,我们由此方向探研得如下两个定理,为熊、米二氏者之推广.     

关于连续线性算子广义预解集的某些结果

讨论了Banach 空间上连续线性算子$T$ 的广义预解集的相关结果,证明了:若$\lambda_0\in\rho_G(T),$ 当~$|\lambda-\lambda_0|<\gamma(T_{\lambda_0})$ 时,$\lambda\in\rho_G(T);$ 与~$\lambda\in\rho_G(T)$ 等价的条件:当~$T_n\to T, 0\in \rho_G(T_n),则~$0\in\rho_G(T);$ 以及$T$ 的柱心~$C_O(T)$ 在数量扰动下的不变性.     

非齐次空间上的奇异积分交换子的有界性

本文在非齐次空间上给出了交换子[b,T](f)=bTf(x)-T(bf)(x)在b(x)是Lipschitz函数时的 Lp(p>1)有界性.     

关于半群局部化的一个注记

证明了对于任何的半群Ｓ和其任何的子半群Ｔ，Ｓ在Ｔ的局部化总是存在的。     

ON THE SENSITIVITY OF THE LDU FACTORIZATION

1　IntroductionG.W.Stewart,X.-W.Chang and A.Barralund etc.have done lot of perturbationanalyses on LU,QR and Cholesky factorizations( see[5] ,[6] ,[1 ] ,[2 ] ,[4 ] ,[3 ] ) .We givesensitivity analysisfor LDU factorization in this paper.The LDU factorization ( or LDMT) is an important method in numerical linear algebra( see [7] ) ,and can be viewed as the general form for LDLT factorization. The differencebetween LDU and LU factorizations in upper triangular matrix U,i.e. U is uni…     

THE EXISTENCE OF OVERLARGE SETS OF IDEMPOTENT QUASIGROUPS

A idempotent quasigroup (Q, o) of order n is equivalent to an n(n-1)×3 partial orthogonal array in which all of rows consist of 3 distinct elements. Let X be a (n+1)-set. Denote by T(n+1) the set of (n+1)n(n-1) ordered triples of X with the property that the 3 coordinates of each ordered triple are distinct. An overlarge set of idempotent quasigroups of order n is a partition of T(n+1) into n+1 n(n-1)×3 partial orthogonal arrays A_x, x∈X based on X\{x}. This article gives an almost complete solution of overlarge sets of idempotent quasigroups.     

双模范畴间同构态射的构造

本文研究了双模范畴上的同构态射.利用代数上常用的构造方法,给出了模范畴R(C:T)和L(C:T)的定义及双模范畴TMC和TMCM之间的同构映射和证明过程,将代数上双模范畴的一些重要结论进行了推广.     

Hiriart—Urruty问题与Clarke广义梯度的若干性质

Ｈｉｒｉａｒｔ—Ｕｒｒｕｔｙ问题与Ｃｌａｒｋｅ广义梯度的若干性质刘晓华（湖南财经学院信息系，长沙４１００７９）１９８８年５月２６日收到，１９９２年４月２９日收到第一次修改稿，１９９３年４月２３日收到第二次修改稿．一、引言Ｈｉｒｉａｒｔ－Ｕｒｒｕｔｙ等...     

ADMISSIBLE ESTIMATES IN THE IMPORTANT CLASS OF ESTIMATES OF THE COVARIANCE MATRIX

Let X1,…XN(where N&gt;m)be independent Nm(μ,∑）random vectors,and put X^-=1/N ∑i=1^N Xi and T‘T=A=∑i=1^N(Xi-X^-)(Xi-X^-)‘,where T is upper-triangular with positive diagonal elements.The author considers the problem of estimating ∑,and restricts his attention to the class of estimates D={T‘△^*T+Nb^*X^-X^‘&#183;△^* is any diagonal matrix and b^* is any nonnegative constant}because it has the following attractive features:(a)Its elements are all quadratic forms of the sufficient and complete statistics(X^-,T).(b)It contains all estimates of the form αA+NbX^-X^-‘(α≥0 and b≥0),which construct a complete subclass of the class of nonnegative quadratic estimates D^8={X‘BX:B≥0}(where X=(X1,…,XN)‘)for any strict convex loss function.(c)It contains all invariant estimates under the transformation group of upper-triangular matrices.The author obtains the characteristics for an estimate of the form.T‘△T+NbX^-X^-‘(△=diag{δ1,…，δm}≥0 and b≥0)of ∑ to be admissible in D when the loss function is chosen as tr(∑^-1∑-I)^2,and shows,by an example,that αA+NX^-X^-‘(α≥0 and b≥0)is admissible in D^* can not imply its admissibility in D.     

人口半群的可微性质

本文通过无穷小母元的谱性质讨论人口半群的性质,证明了:存在 t_0>0,当 t>t_0时,人口半群{T(t)|t≥0)}是可微的.在一个安定的社会中,人口密度函数 P(r,t)满足偏微分方程     

方程u_(tt)=u_(xxt)+f(u_x)_x初边值问题的差分法

The finite difference method is considered for the followinginitial-boundary-value problem: arrayllutt=uxxt+f(ux)x, & (x,t) QT, u(x,0) =(x), & x ［0,1］, ut(x,0) = (x), & x ［0,1］, u(0,t) =u(1,t) =0, & t ［0,T］,array. where f(s),(x) and (x) are given functions;QT=［0,1］ ［0,T］. The convergence of the finite difference schemesis verified by discrete functional analysis methods and prior estimationtechniques.     

三角型模糊数空间的均匀性

用（Ｔ，ｄ）表示全体三角型模糊数构成的度量空间，本文证明了（Ｔ，ｄ）具有某种度量均匀性，并证明了（Ｔ，ｄ）是连通与局部连通的空间。     

THE LARGE TIME GENERIC FORM OF THE SOLUTION TO HAMILTON-JACOBI EQUATIONS

We use Hopf-Lax formula to study local regularity of solution to Hamilton-Jacobi (HJ) equations of multi-dimensional space variables with convex Hamiltonian. Then we give the large time generic form of the solution to We use Hopf-Lax formula to study local regularity of solution to Hamilton-Jacobi (HJ) equations of multi-dimensional space variables with convex Hamiltonian. Then we give the large time generic form of the solution to HJ equation, i.e. for most initial data there exists a constant T > 0, which depends only on the Hamiltonian and initial datum, for t > T the solution of the IVP (1.1) is smooth except for a smooth n-dimensional hypersurface, across which Du(x, t) is discontinuous. And we show that the hypersurface tends asymptotically to a given hypersurface with rate t 1 4 .HJ equation, i.e. for most initial data there exists a constant T > 0, which depends only on the Hamiltonian and initial datum, for t > T the solution of the IVP (1.1) is smooth except for a smooth n-dimensional hypersurface, across which Du(x, t) is discontinuous. And we show that the hypersurface tends asymptotically to a given hypersurface with rate t-1/4 .     

THE （u＋К）-ORBIT OF ESSENTIALLY NORMAL OPERATORS AND COMPACT PERTURBATIONS OF STRONGLY IRREDUCIBLE OPERATORS

Let Н be a complex,separable,infinite dimensional Hilbert space,T∈L(Н),(U+κ)(T) denotes the (U+κ)-orbit of T,i.e.,(U+κ)(T)={R^-1 TR:R is invertible and of the form unitary plus compact}.Let Ω be an analytic and simply connected Cauchy domain in C and n∈N,A（Ω,n）denotes the class of operators,each of which satisfies (i) T is essentially normal;(ii)σ(T)=Ω^-,ρF（T）∩σ（T）=Ω;（iii）ind(λ-T)=-n,nul(λ-T)=0,(λ∈Ω）。it is proved that given T1,T2∈A(Ω,n）and c&gt;0,there exists a compact operator K with ||K||&lt;ε such that T1+K∈(u+κ)(T2),this result generalizes a result of P.S.Guinand and L.Marcoux[6,15],Furthermore,the authors give a character of the norm closure of (u+κ)(T),and prove that for each T∈А(Ω,n）,there exists a compact (SI) perturbation of T whose norm can be arbitrarily small.     

A C*-ALGEBRA APPROACH TO THE IRREDUCIBILITY OF COWEN-DOUGLAS OPERATORS

LetHbeaseparableindnitedimensionalHilbertspaceoverthefieldCandletL(H)(resp.K(H))denotethealgebraofallboundedlinearoperators(resp.allcompactoperators)onH.ForTEL(H),wedenotebyR(T)(resp.KerT)therange(resp.thenullspace)ofT.Accordingto[2],Bit(fl)consistsofallCowen-DouglasoperatorsTEL(H)satisfyingfollowingconditions:(l)fiCa(T)isaconectedopensubsetinC;(2)R(w--T)=HanddimKer(w--T)=n相似文献   

THE INTEGRAL COMPONENT OF AN ORDER BOUNDED TRANSFORMATION

Summary

Assume that T:L→M is a positive transformation from an arbitrary Riesz space L into a Dedekind complete Riesz space M, and let T=T_c + T_s be the decomposition of T into its integral component T_c and its singular component T_s.

In this note we give an elementary proof of the fact that for every o ? u ? L

T_c u = inf(s_nup Tu_n: o ? u_n + u),

under the conditionns stated above. This generalizes a recent result of C.D. Aliprantis [1].     

关于一类广义Tikhonov 正则化方法的饱和效应分析

Tikhonov正则化方法是研究不适定问题最重要的正则化方法之一,但由于这种方法的饱和效应出现的太早,使得无法随着对解的光滑性假设的提高而提高正则逼近解的收敛率,也即对高的光滑性假设,正则解与准确解的误差估计不可能达到阶数最优.Schrroter T 和Tautenhahn U给出了一类广义Tikhonov正则化方法并重点讨论了它的最优误差估计, 但却未能对该方法的饱和效应进行研究.本文对此进行了仔细分析,并发现此方法可以防止饱和效应,而且数值试验结果表明此方法计算效果良好.     

ISOLATED POINTS OF THE APPROXIMATE POINT SPECTRUM OF CERTAIN LATTICE HOMOMORPHISMS ON Co (X)

Abstract

Suppose X is a locally compact Hausdorff space and C (X) the apace of all continuous complex valued functions on X which vanish at infinity. Let T be a (complex) linear lattice homomorphism on C_o (X) whose adjoint is also a lattice homomorphism. It is sham that every non-zero isolated point of the approximate point spectrum of T lies in the point spectrum of T. An example is given to show that the exclusion of zero is necessary, even when X is compact. The same techniques are then used to show that if also the spectrum of T is finite then T can be written, in a natural manner, as a direct sum of two such lattice homomorphisms; one being an n'th root of an invertible multiplication operator and the other quasi-nilpotent.     

关于零级亚纯函数的一类新的奇异方向

本文研究了平面上的亚纯函数的奇异方向,利用Tsuji’s的第二基本定理和几个已有的关于函数增长性估计的引理,证明了平面上的零级亚纯函数至少存在一条T方向,这种方向直接以特征函数为比较函数,克服了Borel方向的定义中关于增长级不能为零的限制.     

与平面凸集几何量有关的不等式(英文)

本文研究了平面凸集几何量之间的关系.通过定义新几何量:平面凸集的最大内接正三角形T和最大内接正方形S,分别获得了T(S)的边长、凸集的直径和面积之间的关系式.