某些椭圆曲线的L—级数的L（1）的非零性

本文考虑了椭圆曲线ΓＤ：Ｘ＾３＋Ｙ＾３＝ＤＺ＾３。以ＬＤ（ｓ）记ΓＤ的ＨｅｃｋｅＬ－级数。由ＬＤ（ｓ）的解析延拓我们将ＬＤ（１）展成有限项之和，然后通过建立ｙ＾２＝ｘ＾３－１６的一个处处有好的约化的模型，证明了当ｐ≡２或５（ｍｏｄ９）时，Ｌｐ（１）≠０，Ｌｐ＾２（１）≠０。这些结果是对Ｂｉｒｃｈ和Ｓｗｉｎｎｅｒｆｏｎ－Ｄｙｅｒ猜想的支持。     

关于一类S~（1，1）_3（△~（2）_（mn））插值与逼近

设△￣（２）＿（ｍｘ）是矩形域Ｄ＝［ａ，ｂ］［ｃ，ｄ］的Ⅱ－型三角剖分．Ｓ￣（１，１）＿３（△￣（２）＿（ｍｘ）是带边界条件的三元三次样条空间：本文我们将讨论一类Ｓ￣（１，１）＿３（△￣（２）＿（ｍｘ））的插值问题，证明了它的存在性，唯一性及逼近阶：如果ｆ∈Ｃ￣４（Ｄ），则有｜ｆ－ｓ｜≤ｋ（ｌ）．ｍａｘ（ρ△，ρ￣（－１）＿△）．‖ｆ‖．．ｈ￣２．     

Riccati微分方程的可积条件

Ｉｎ１９９８,ＺｈａｏＬｉｎｌｏｎｇ［１］ｏｂｔａｉｎｅｄｔｈｅｉｎｔｅｇｒａｂｌｅｃｏｎｄｉｔｉｏｎ：Ｒ＝１αγＰｅ２∫（Ｑ－βＤ）ｄｘ　　　（α,β,γｉｓｃｏｎｓｔ）．（１）ＦｏｒＲｉｃｃａｔｉｅｑｕａｔｉｏｎ：ｙ′＝ｐ（ｘ）ｙ２＋Ｑ（ｘ）ｙ＋Ｒ（ｘ）　　（ＰＲ≠０）．（２）　　Ｈｅｒｅｔｈｅｎｅｗｉｎｔｅｇｒａｂｌｅｃｏｎｄｉｔｉｏｎｓｉｓｇｉｖｅｎ：Ｌ［ｙ０］＝１αγＰｅ２∫（Ｑ＋２ｙ０ｐ－βＤ）ｄｘ．（３）Ｌ［ＡＢ＋ｙ０］＝１αγ（ＡＢ）２Ｌ［ｙ０］ｅ２∫（２ＢＡＬ［ｙ０］＋Ｑ＋２ｙ…     

一类沿曲面的奇异积分算子的L~p－有界性

设ｎ≥３，记∑＿（ｎ－２）是Ｒ￣（ｎ－１）中的单位球面。本文研究了当Ω为Ｒ￣（ｎ－１）上的零次齐次函数，满足消失性条件且Ω∈时，沿某类曲面（ｔ，г（｜ｔ｜））的下列奇异积分算子Ｔｆ（ｘ，ｘ＿ｎ）＝ｐ．ｖ．ｄｔ及其极大算子的Ｌ￣ｐ（Ｒ￣ｎ）－有界性，其中ｂ为有界径向函数，ｘ∈Ｒ￣（ｎ－１），ｘ＿ｎ∈Ｒ且１＜ｐ＜∞．     

平面二次系统极限环（1,3）分布的讨论

本文（ａ）对文献［１］中的定理２进行了修正，取消了假设条件Ｖ＿７＞０；（ｂ）对曲线Ｍ（ｓ￣２，ｒ）＝０，Ｊ（ｓ￣２，ｒ）＝０，Ｌ（ｓ￣２，ｒ）＝０，Ｔ（ｓ￣２，ｒ）＝０，ｓ￣２＝ｓ以及ｓ￣２＝ｓ的位置关系进行了讨论，在保证系统（１．１）具有极限环（１，３）分布的情况下，扩大了参数（ｓ，ｒ）的变化范围，并用图示给以清晰说明：（ｃ）讨论了一类具有两个无限远奇点的平面二次系统极限环的（１，３）分布：（ｄ）对系统（１．１）不论它在无限远处出现一个、两个或三个奇点，给出了出现极限环线（１，３）分布的统一处理方法。     

权为任意正实数的Poincare级数（I）非解析的情形

设ｒ为一个正实数，１＜ｒ＜２，是一个Ｈ－群，ｖ：Γ→Ｃ是一个乘子系（定义见§１）．在本文中我们定义了所谓非解析的Ｐｏｉｎｃａｒｅ级数Ｐ＿（ｎｒ）（ｚ，ｓ，ｖ，Ａ＿ｊ，Γ，ｋ＿ｊ）（§２），求出了它的Ｆｏｕｒｉｅｒ展开式，应用Ｌａｐｌａｃｉａｎ算子的谱及Ｓｅｌｂｅｒｇ的Ｚｅｔａ函数，我们证明了Ｐ＿（ｎｒ）（ｚ，ｓ，ｖ，Ａ＿ｊ，Γ，ｋ＿ｊ）可以解析延拓到包含ｓ＝０的一个半平面Ｒｅ（ｓ）＞一δ中去。从而为我们研究解析Ｐｏｉｎｃａｒｅ级数作好了准备。     

一个素变数丢番图不等式

本文证明了如果１＜ｃ＜２３７／２１４，则对于充分大的Ｎ和ε≥Ｎ－１／５（２３７／２１４－ｃ）＋ｖ（ｖ＞０）表达式Ｄ（Ｎ）：＝Σ｜ｐｃ１＋ｐｃ２＋ｐｃ３－Ｎ｜＜－εｌｏｇｐ１ｌｏｇｐ２ｌｏｇｐ３ 关于素变数ｐ１，ｐ２，ｐ３有渐近公式，改进了文献［１］的结果１＜Ｃ＜１．１．     

Fourier-Jacobi展开的Riesz平均

对ｆ∈Ｌｐ（Ｒ＋，Δ（ｔ）ｄｔ），Δ（ｔ）＝（２ｓｉｎｈｔ）２α＋１（２ｃｏｓｈｔ）２β＋１，１ｐ２，本文证明了当Ｒｅｚ＞（２／ｐ－１）（α＋１／２）时，ｆ的Ｆｏｕｒｉｅｒ－Ｊａｃｏｂｉ展开的ｚ－阶Ｒｉｅｓｚ平均几乎处处收敛于ｆ．该结果推广了Ｇｉｕｌｉｎｉ和Ｍａｕｃｅｒｉ在实秩为１的对称空间上的相应结果     

The Problem of Periodic Solution for Dynamical Systems（Ⅱ）

§１．　ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔ：Ｈ：Ｒｎ×Ｒｎ→ＲｂｅａｓｍｏｏｔｈＨａｍｉｌｔｏｎｆｕｎｃｔｉｏｎ（ｑ，ｐ）→Ｈ（ｑ，ｐ）Ｇ：Ｒｎ×Ｒｎ→Ｒ２ｎｂｅｓｍｏｏｔｈｏｐｅｒａｔｏｒ（ｑ，ｐ）→Ｇ（ｑ，ｐ）＝（ｇ１（ｑ，ｐ），…，ｇ２ｎ（ｑ，ｐ））．　　Ｗｅｄｅｆｉｎｅｔｗｏｓｐａｃｅｓ：Ｌ＝ｓｐａｎ｛ｇｉ，｛Ｈ，ｇｉ｝，｛Ｈ，｛Ｈ，ｇｉ｝｝，…，ｉ＝１，２，…，２ｎ｝ｄＬ（ｚ）＝｛ｄｆ（ｚ）｜ｆ∈Ｌ｝　ｚ∈Ｒｎ×Ｒｎ．Ｈｅｒｅ｛，｝ｉｓｐｏｉｓｓｏｎｂｒａｃｋｅｔ．Ｔｈｒｏｕｇｈｏｕｔｔｈ…     

某些周期卷积类上的最佳单边逼近

设Ｋ满足性质Ｂ（或Ｋ是ＮＣＶＤ核），本文得到了以Ｋ为核的卷积类Ｂ＿ｐ（或Ｋ＿ｐ），１≤ｐ≤∞，在Ｌ＿１尺度下，借助于三角多项式和周期样条的单边逼近的精确值．ｈ，ｆ⊥Ｓ，则ｈ⊥Ｓ，结合（４．７）我们易知Ｆ∈Ｓ￣－（Ｇ￣＊），且Ｆ⊥Ｓ，Ｆ（０）＝０．由引理６得由引理７得进一步地根据定理２，我们可得（４．６）及（４．８）得另一方面．根据［２］（定理１．７．５）及引理８得由（４．８）、（４．１０）定理得证．作者感谢导师孙永生教授的悉心指导．参考文献     

Estimation of the number of components of finite mixtures of multivariate distributions

An estimator of the number of components of a finite mixture ofk-dimensional distributions is given on the basis of a one-dimensional independent random sample obtained by a transformation of ak-dimensional independent random sample. A consistency of the estimator is shown. Some simulation results are given in a case of finite mixtures of two-dimensional normal distributions.     

Eigenvector p-Bases of Rings of Constants of Derivations

Let A be a UFD of characteristic p > 0, let 𝒵 be a set of some eigenvectors of a derivation of A. We prove, under some additional assumptions, a necessary and sufficient condition for 𝒵 to be a p-basis of the minimal ring of constants containing 𝒵. The main preparatory result is the unique decomposition theorem with respect to a factor from a given subalgebra containing A^p.     

Galois Structure of K-Groups of Rings of Integers

N/Kbe a Galois extension of number fields with finite Galois group G.We describe a new approach for constructing invariants of the G-module structure of the K groups of the ring of integers of N in the Grothendieck group of finitely generated projective Z[G]modules. In various cases we can relate these classes, and their function field counterparts, to the root number class of Fröhlich and Cassou-Noguès.     

有资格限制的指派问题的求解方法

在实际的指派工作中，常会遇到某个人有没有资格去承担某项工作的问题，因此，本建立了有资格限制的指派问题的数学模型。在此数学模型中，将效益矩阵转化为判定矩阵，由此给出了判定此种指派问题是否有解的方法；在有解的情况下，进一步将效益矩阵转化为求解矩阵，从而将有资格限制的指派问题化为传统的指派问题来求解。最后给出了一个数值例子来说明这样的处理方法是有效的。     

On Sums of Coefficients of Products of Polynomials

We study the nilpotency of the sums of all coefficients of some sorts of products of polynomials over reversible, IFP, and NI rings, and introduce an SCN ring as a generalization. We characterize SCN rings in relation with related ring properties, and also provide several useful properties and ring extensions of SCN rings.     

Convergence of sequences of sets of associated primes

It is a well-known result of M. Brodmann that if is an ideal of a commutative Noetherian ring , then the set of associated primes of the -th power of is constant for all large . This paper is concerned with the following question: given a prime ideal of which is known to be in for all large integers , can one identify a term of the sequence beyond which will subsequently be an ever-present? This paper presents some results about convergence of sequences of sets of associated primes of graded components of finitely generated graded modules over a standard positively graded commutative Noetherian ring; those results are then applied to the above question.

     

Rates of Convergence of Means of Euclidean Functionals

Let L be the Euclidean functional with p-th power-weighted edges. Examples include the sum of the p-th power-weighted lengths of the edges in minimal spanning trees, traveling salesman tours, and minimal matchings. Motivated by the works of Steele, Redmond and Yukich (Ann. Appl. Probab. 4, 1057–1073, 1994, Stoch. Process. Appl. 61, 289–304, 1996) have shown that for n i.i.d. sample points {X ₁,…,X _n } from [0,1] ^d , L({X ₁,…,X _n })/n ^(d−p)/d converges a.s. to a finite constant. Here we bound the rate of convergence of EL({X ₁,…,X _n })/n ^(d−p)/d . Y. Koo supported by the BK21 project of the Department of Mathematics, Sungkyunkwan University. S. Lee supported by the BK21 project of the Department of Mathematics, Yonsei University.     

Number of connected components of groups of real points of adjoint groups

We present a unified approach to compute the number of connected components in the group of real points of adjoint almost simple real algebraic groups.     

Enumeration of perfect matchings of a type of Cartesian products of graphs

Let G be a graph and let Pm(G) denote the number of perfect matchings of G.We denote the path with m vertices by P_m and the Cartesian product of graphs G and H by G×H. In this paper, as the continuance of our paper [W. Yan, F. Zhang, Enumeration of perfect matchings of graphs with reflective symmetry by Pfaffians, Adv. Appl. Math. 32 (2004) 175-188], we enumerate perfect matchings in a type of Cartesian products of graphs by the Pfaffian method, which was discovered by Kasteleyn. Here are some of our results:1. Let T be a tree and let C_n denote the cycle with n vertices. Then Pm(C₄×T)=∏(2+α²), where the product ranges over all eigenvalues α of T. Moreover, we prove that Pm(C₄×T) is always a square or double a square.2. Let T be a tree. Then Pm(P₄×T)=∏(1+3α²+α⁴), where the product ranges over all non-negative eigenvalues α of T.3. Let T be a tree with a perfect matching. Then Pm(P₃×T)=∏(2+α²), where the product ranges over all positive eigenvalues α of T. Moreover, we prove that Pm(C₄×T)=[Pm(P₃×T)]².