数学问题解答

数学问题解答１９９６年４月号问题解答（解答由问题提供人给出）ＩＯＯ６在等腰凸ＡＢＣ中，顶角Ｂ—２０”，在边ＢＣ，ＡＢ上分别取点Ｄ，Ｅ，有ＺＤＡＣ＝６０“，ＺＡＣＥ＝５０”，求ＺＡＤＥ．一解设／＊＊Ｅ一。，则易知：凸ＡＤＥ面积凸ＢＤＥ面积凸＊＊Ｅ面积Ａ...     

一类改进的非凸二次规划有效集方法

一类改进的非凸二次规划有效集方法修乃华（河北师范学院数学系）ＡＣＬＡＳＳＯＦＩＭＰＲＯＶＥＤＡＣＴＩＶＥＳＥＴＭＥＴＨＯＤＳＦＯＲＮＯＮＣＯＮＶＥＸＱＵＡＤＲＡＴＩＣＰＲＯＧＲＡＭＭＩＮＧＰＲＯＢＬＥＭ￥ＸｉｕＮａｉ－ｈｕａ（Ｄｅｐｔ．ｏｆＭａｔｈ．...     

Bergman空间A~p（ψ）中函数之零点

设Ｄ是Ｃ中的单位圆盘及为［０，１）上的正规函数。对于０＜Ｐ＜∞，这样的函数用于定义一个带权为￣ｐ（｜ｚ｜）／（１－｜ｚ｜￣２）的Ｂｅｒｇｍａｎ空间Ａ￣ｐ．本文刻画了Ａ￣ｐ中函数之零点集的结构．作为应用，又给出了Ａ￣ｐ中函数序列插值的条件。     

集值映射多目标规划问题的解集的连通性

本文研究了无限维空间里集值映射的多目标规划问题。主要结果是：当目标函数为类凸的集值映射时，其目标空间里的有效点集是连通的；若目标函数为Ｃ－凸的集值映射时，其有效解集也连通。     

关于度量投影的连续性

本文引入的Ｂａｎａｃｈ空间的（Ｃ－Ｉ）、（Ｃ－Ⅱ），（Ｃ－Ⅲ）等几何性质，证明了如下结果。设Ｍ是Ｂａｎａｃｈ空间的逼近凸子集，如果Ｂａｎａｃｈ空间有性质（Ｃ－Ｉ），（Ｃ－Ⅱ）（Ｃ－Ⅲ），则度量投影ＰＭ连续（范数－范数上半连续，范数－弱上半连续）。这些结果推广了文（４，７，８）相应的定理。最近，Ｄ．Ｋｕｔｚａｒｏｖａ，Ｂｏｒ－Ｌｕｈ Ｌｉｎ等引入了一些新的凸性空间，本文还研究了这些凸性空间中度量投影     

具有奇特征p的群ZpZ作用的Enriques曲面

本文考虑在奇特征的群Ｚ／ｐＺ作用下的Ｅｎｒｉｑｕｅｓ曲面，证明了：如果在此群的作用下，Ｅｎｒｉｑｕｅｓ曲面的不动点集含有一条整曲线Ｃ，那么ｐａ（Ｃ）＜６；并且当ｐａ（Ｃ）３时，｜Ｃ｜不是超椭圆的．     

一致凸Banach空间中渐近非扩张族的几乎轨道的弱收敛性

设Ｅ是一个有Ｆｒｅｃｈｅｔ可微范数的一致凸Ｂａｎａｃｈ空间，＝｛Ｔ；：ｔ∈Ｓ｝是Ｅ的闭凸子集Ｃ上的一个渐近非扩张族，ｕ：Ｓ→Ｃ是的一个几乎轨道．假设其中Ｆ是Ｔ，ｓ∈Ｓ．的所有公共不动点之集．证明了，如果Ｗｗ（｛ｕ（ｔ）：ｔ∈Ｓ｝，其中，Ｗｗ（｛ｕ（ｔ）：ｔ∈Ｓ｝）是网｛ｕ（ｔ）：ｔ∈Ｓ｝的子网的所有弱极限点之集，则ｕ（ｔ）弱收敛到Ｆ（）的某个元素．     

自由支配集下近似平衡约束向量优化问题的稳定性研究

在自由支配集下,对一类近似平衡约束向量优化问题（AOPVF）的稳定性进行研究.首先,在较弱的凸性假设下获得了约束集映射的Berge-半连续性和约束集的闭性、凸性和紧性结果.然后,在目标函数列Gamma-收敛的假设下,分别得到了AOPVF弱有效解映射Berge 半连续和弱有效解集下Painlevé-Kuratowski收敛的充分条件,并给出例子说明结论是新颖和有意义的.     

分裂空间的一个性质

设Ｘ为一个拓扑空间，对于任意的Ａ∈Ｘ。存在可分度量空间Ｍ及连续映射ｆ：Ｘ→Ｍ，使得ｆ（Ｘ）＝Ｍ，Ａ＝ｆ＾－１（ｆ（Ａ）），则Ｘ称为分裂空间。本文证明了分裂空间Ｘ在广义连续统假设下：（１）若ｄ（Ｘ）≥２＾ω，则ｄ（Ｘ）＝｜Ｘ｜。（２）若（Ｘ）≤２＾ω，则对角线集△ｘ为Ｇδ集。并且（１）中的条件不能减弱。     

非凸集值映射的包含切性及应用

本文在一般的Ｂａｎａｃｈ空间Ｘ中研究从非空闭集ＫＸ到Ｘ的非凸集值映射Ｆ的包含切性问题．得到的结果定理３．１把有关的结论推广到非光滑空间，定理３．３则将有限维空间的正则性定理推广到任意的Ｂａｎａｃｈ空间．作为结果的应用，我们证明了无穷维非凸微分包含和非凸控制系统生存解的存在性，且给出了一个方便的等价切性条件．     

Estimation of the measure of the image of the ball

Under study is the class of ring Q-homeomorphisms with respect to the p-module. We establish a criterion for a function to belong to the class and solve a problem that stems from M. A. Lavrentiev [1] on the estimation of the measure of the image of the ball under these mappings. We also address the asymptotic behavior of these mappings at a point.     

On the distributions of the ratios of the extreme roots to the trace of the Wishart matrix

In this paper, the authors cosider the derivation of the exact distributions of the ratios of the extreme roots to the trace of the Wishart matrix. Also, exact percentage points of these distributions are given and their applications are discussed.     

On the rational approximation of the sum of the reciprocals of the Fermat numbers

Let $\mathcal{G}(z):=\sum_{n\geqslant0} z^{2^{n}}(1-z^{2^{n}})^{-1}$ denote the generating function of the ruler function, and $\mathcal {F}(z):=\sum_{n\geqslant} z^{2^{n}}(1+z^{2^{n}})^{-1}$ ; note that the special value $\mathcal{F}(1/2)$ is the sum of the reciprocals of the Fermat numbers $F_{n}:=2^{2^{n}}+1$ . The functions $\mathcal{F}(z)$ and $\mathcal{G}(z)$ as well as their special values have been studied by Mahler, Golomb, Schwarz, and Duverney; it is known that the numbers $\mathcal {F}(\alpha)$ and $\mathcal{G}(\alpha)$ are transcendental for all algebraic numbers α which satisfy 0<α<1. For a sequence u, denote the Hankel matrix $H_{n}^{p}(\mathbf {u}):=(u({p+i+j-2}))_{1\leqslant i,j\leqslant n}$ . Let α be a real number. The irrationality exponent μ(α) is defined as the supremum of the set of real numbers μ such that the inequality |α?p/q|<q ^?μ has infinitely many solutions (p,q)∈?×?. In this paper, we first prove that the determinants of $H_{n}^{1}(\mathbf {g})$ and $H_{n}^{1}(\mathbf{f})$ are nonzero for every n?1. We then use this result to prove that for b?2 the irrationality exponents $\mu(\mathcal{F}(1/b))$ and $\mu(\mathcal{G}(1/b))$ are equal to 2; in particular, the irrationality exponent of the sum of the reciprocals of the Fermat numbers is 2.     

Refinement of the asymptotics of the power of the quantile test

One investigates the asymptotic properties of the quantile test, similar to the properties of the Pearson's chi-square test of fit.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 153, pp. 5–15, 1986.The author is grateful to D. M. Chibisov for useful remarks.     

On the approximation of positive operators and the behaviour of the spectra of the approximants

LetT be a positive linear operator on the Banach latticeE and let (S _n ) be a sequence of bounded linear operators onE which converge strongly toT. Our main results are concerned with the question under which additional assumptions onS _n andT the peripheral spectra (S _n ) ofS _n converge to the peripheral spectrum (T) ofT. We are able to treat even the more general case of discretely convergent sequences of operators.