Smith normal forms of incidence matrices

A brief introduction is given to the topic of Smith normal forms of incidence matrices. A general discussion of techniques is illustrated by some classical examples. Some recent advances are described and the limits of our current understanding are indicated.     

NEW NORMAL FORMS FOR NONLINEAR SYSTEMS (Ⅱ)——CONTROLLABLE FORM

This paper proposes a sort of new normal forms consisting of observer form and controllable form for nonlinear systems. The conditions for transforming to these normal forms are given, respectively. These normal forms are used to treat the problems of observer design and linearization. The first part of this paper deals with the observer form, and the second the controllable form.     

On the index of finite determinacy of vector fields with resonances

In this paper we study normal forms for a class of germs of 1-resonant vector fields on R^n with mutually different eigenvalues which may admit extraneous resonance relations. We give an estimation on the index of finite determinacy from above as well as the essentially simplified polynomial normal forms for such vector fields. In the case that a vector field has a zero eigenvalue, the result leads to an interesting corollary, a linear dependence of the derivatives of the hyperbolic variables on the central variable.     

利用有限局部环Z/pkZ上的幂等矩阵的标准型构作认证码

In this paper,we determine the normal forms of idempotent matrices for similarity over finite local rings Z/p~kZ,from which we construct a Cartesian au- thentication code and compute its size parameters and the probabilities of successful impersonation and substitution attack under the hypothesis that the cecoding rules are chosen according to a uniform probability distribution.     

Diffusion-induced Spatio-temporal Oscillations in an Epidemic Model with Two Delays

We investigate a diffusive, stage-structured epidemic model with the maturation delay and freelymoving delay. Choosing delays and diffusive rates as bifurcation parameters, the only possible way to destabilize the endemic equilibrium is through Hopf bifurcation. The normal forms of Hopf bifurcations on the center manifold are calculated, and explicit formulae determining the criticality of bifurcations are derived. There are two different kinds of stable oscillations near the first bifurcation: ...     

整数规划中的正则分解

In this paper, we study the problem of regular decomposition in integer programming. We apply the radical of binomial ideal and universal Gr¨obner bases to get the regular decomposition forms of a finite integer lattice point set. We indicate the relationship between state polytope and regular decompositions, i.e., an edge of state polytope corresponds to a binomial which decides one of regular decomposition forms of a finite integer lattice point set.     

On the Mean Absolute Geodesic Curvature of Closed Curves in 2-Dimensional Space Forms

In this paper,we establish some formulas on closed curves in 2-dimensional space forms.Mean absolute geodesic curvature is introduced to describe the average curving of a closed curve.Inthis sense,a closed curve could be compared with a geodesic circle that is the boundary of a convex geodesic circular disk containing the closed curve.The comparison can be used to show some properties of space forms only on themselves.     

关于正规族的一个判别法

In 1964,Hayman,W.K.Predicated method of judging a functin family to be normal variety.This result was proved in 1985.Here.we give a method thawt judges a function family to be normal variety by using of higher derivative I t is a generlization of previous result.     

Normal forms for periodic orbits of real vector fields

We consider normal forms of real vector fields near periodic orbits and provide sufficient conditions for their smooth linearization. In addition, the main results also assert the existence of vertical local foliations, whose leaves are all transversal to the periodic orbit.