Existence of an Angular Density of Roots of Entire Functions of Order Zero

We obtain sufficient conditions for the set of roots of an entire function of order zero of strongly regular growth to possess an angular density.     

光子晶体光纤的色散特性

本文用有效折射率模型 ,分析了光子晶体光纤的色散特性 ,定量给出了光子晶体光纤双折射特性与光纤参数之间的关系 ,指出了光子晶体光纤具有多个零色散波长 ,对相关现象作出了合理的解释。     

One Class of Hyperbolic Function Equation and Its Application

ＯｎｅＣｌａｓｓｏｆＨｙｐｅｒｂｏｌｉｃＦｕｎｃｔｉｏｎＥｑｕａｔｉｏｎａｎｄ　Ｉｔｓ　ＡｐｐｌｉｃａｔｉｏｎＢａｉＦｅｎｇｔｕ（白凤图）（ＮｏｒｔｈＣｈｉｎａＩｎｓｔｉｔｕｔｅｏｆＷａｔｅｒＣｏｎｓｅｒｖａｎｃｙａｎｄＨｙｄｒｏ－ｐｏｗｅｒ）Ａｂｓ...     

极低码率视频压缩编码算法的改进方法

本文从系统结构出发，充分利用低码率系统的特点，提出一种基于自适应判断的改进方法，较之已报道的方法，本文算法在基本保证图像质量的同时，有效地避免了一些冗余计算。将系统的基本运算量需求（不计运动估值算法的影响）降低到原来的５０％，从而使系统速度提高。由于该方法改进的角度较为新颖、独立，如果和其他快速算法相补充、结合使用，可以获得更优的性能。因此，本文算法在视频压缩系统中有较广泛的发展前景。     

Accuracy of the zero crossings of the second directional derivative as an edge detector

In this paper the accuracy of the second directional derivative edge detector is analyzed, based on a number of idealized edge models. The results are compared with those for the Laplacian edge detector. Errors are shown to be small under a number of conditions. These conditions are less severe for the second directional derivative than for the Laplacian edge detector. Spurious or phantom edges can be removed by checking the sign of the third directional derivative, though this is not enough to remove all large errors. Indeed, it is also shown that large errors will be obtained if no threshold is set on the magnitude of a third order derivative.This work was supported by the Belgian National Fund for Scientific Research (NFWO).     

New Semiclassical and Numerical Approaches to Locate Zeros of Wave Functions Asiri Nanayakkara

A new semiclassical method is presented for evaluating zeros of wave functions. In this method, locating zeros of the wave functions of Schrodinger equation is converted to finding roots of a polynomial. The coefficients of this polynomial are evaluated using WKB and semi quantum action variable methods. For certain potentials WKB expressions for moments are obtained exactly. Almost explicit formulae for moments are obtained for the potential V (x) = xN. Examples are given to illustrate both methods. Using semi quantum action variable method, complex zeros of the wave functions of the PT symmetric complex system V(x) = x4 iAx are obtained. These zeros exhibit complex version of interlacing.     

On a partition analog of the Cauchy-Davenport theorem

Summary Let G be a finite abelian group, and let n be a positive integer. From the Cauchy-Davenport Theorem it follows that if G is a cyclic group of prime order, then any collection of n subsets A_1,A_2,\ldots,A_n of G satisfies \bigg|\sum_{i=1}^n A_i\bigg| \ge \min \bigg\{|G|,\,\sum_{i=1}^n |A_i|-n+1\bigg\}. M.~Kneser generalized the Cauchy--Davenport Theorem for any abelian group. In this paper, we prove a sequence-partition analog of the Cauchy--Davenport Theorem along the lines of Kneser's Theorem. A particular case of our theorem was proved by J.~E. Olson in the context of the Erdős--Ginzburg--Ziv Theorem.     

多项式矩阵理论在网络分析中的应用

本文应用基本回路矩阵Ｂ、基本割集矩阵Ｑ和支路伏安特性矩阵［Ｙ（ｓ）Ｚ（ｓ）］列写出线性时不变有源网络的网络矩阵Ｐ（ｓ），借助于多项式矩阵理论中有关解耦零点的概念和理论，研究了网络的复杂度和稳定性。和文献［３］相比，不仅降低Ｐ（ｓ）阶次，减少了运算，且研究了复杂度。