On the Construction of Some Type II Codes over Z 4×Z4

We consider here the construction of Type II codes over the abelian group Z₄×Z₄. The definition of Type II codes here is based on the definitions introduced by Bannai [2]. The emphasis is given on the construction of these types of codes over the abelian group Z₄×Z₄ and in particular, the methods applied by Gaborit [7] in the construction of codes over Z₄ was extended to four different dualities with their corresponding weight functions (maps assigning weights to the alphabets of the code). In order to do this, we use the flattened form of the codes and construct binary codes analogous to the ones applied to Z₄ codes. Since each duality generates more than one weight function, we focus on those weights satisfying the squareness property. Here, by the squareness property, we mean that the weight function wt assigns the weight 0 to the Z₄×Z₄ elements (0, 0),(2, 2) and the weight 4 to the elements (0, 2) and (2, 0). The main results of this paper are focused on the characterization of these codes and provide a method of construction that can be applied in the generation of such codes whose weight functions satisfy the squareness property.     

凸函数的双参数平均不等式的新证明

利用 Tchebycheff积分不等式和积分形式的 Cauchy中值定理证明了下列结论 :设 f(x)是 [a,b]上的正连续函数 ,且在 (a,b)内可微 ,若 f′(x)单调递增 ,则对任意的 p,q,有 Mp,q(f) 相似文献   

Structure and properties of the δ‐form and mesophase of syndiotactic polystyrene membranes prepared from different organic solvents

Syndiotactic polystyrene (sPS) membranes were prepared with different organic solvent systems and compared to get the information about the δ‐form complexing behavior of sPS. Further, the guest molecules included in the clathrate δ form of sPS are removed by stepwise extraction method. The conformational changes during the TTGG helical formation of sPS/organic solvent systems have been identified by FTIR spectroscopy, and it was concluded that the TTGG helices were constructed in regular sequences, which depends on the nature of the respective solvents. The TTGG content in the mesophase is found to be increased by removing the guest molecules. The structural changes of sPS/organic solvent systems have been characterized by WAXD analysis. Moreover, the different clathrate structures were found and showed the different crystalline reflections in the WAXD profiles, which are significantly changed with the kind of guest solvent included in sPS. The content of solvents in the clathrated sPS and the desorption temperatures were determined by thermal analysis. The resulted mesophase of sPS membrane contains the nanoporous molecular cavities that depend on the size of the guest molecule. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1873–1880, 2005     

一维Brown运动图集的拟几乎处处Hausdorf维数

证明了一维Ｂｒｏｗｎ运动图集的Ｈａｕｓｄｏｒｆ维数拟几乎处处等于３／２．     

Nonlinear stability of a defective cylindrical shell

A cylindrical shell with a shape defect is studied. A one DOF modelling is derived. Its nonlinear behaviour is investigated by using both harmonic balance method and normal form theory. Stability domains are computed according to 2 parameters related to the frequency and the amplitude of the external forcing.     

On the linear independence of certain numbers

With the help of a version of Siegel’s method, we establish in a fairly general case the linear independence of values of hypergeometric functions with irrational parameters and their derivatives; the corresponding quantitative results are obtained. Translated fromMatematicheskie Zametki, Vol. 62, No. 3, pp. 383–390, September, 1997. Translated by A. M. Chebotarev     

An extension of flanders theorem to several matrices

The Flanders Theorem relates the matrices AB and BA and provides a necessary and sufficient condition for the consistency of the matrix system P = ABQ = BA In this paper, we generalize the Flanders condition for several matrices.     

质量变化对力学系统形式不变性和守恒量的影响

研究质量变化对力学系统形式不变性和守恒量的影响.给出常质量系统和变质量系形式不变性的判据方程.比较两个判据方程得到质量变化时形式不变性仍保持的条件.给出两个系统有同样守恒量的条件.举例说明结果的应用. 关键词： 分析力学 变质量系统 形式不变性 守恒量     

条件正定型与扩张

讨论条件正定型与扩张问题．得到了Pontrjagin空间上对称算子的扩张定理．     

Variational formulation of three-dimensional viscous free-surface flows: Natural imposition of surface tension boundary conditions

We present a new surface-intrinsic linear form for the treatment of normal and tangential surface tension boundary conditions in C⁰-geometry variational discretizations of viscous incompressible free-surface flows in three space dimensions. The new approach is illustrated by a finite (spectral) element unsteady Navier-Stokes analysis of the stability of a falling liquid film.