In this paper,it is presented a necessary and sufficient condition for the likelihood estimates about parameters a and b to be finite,positive and unique when the software failure data is interfailure data or grouped data.

The necessary condition that X(v)exists limit cycles is that the 2×2 matrix A have complex eigenvalues, and some sufficient conditions that X(v)exists limit cycles and unique limit cycle are given,where f(v) may be non-homogeneous function.

Because the solution is not unique,the L X 1 adjustment method is proposed in this paper.

In the perspective of culture , the “uniqueness” of his patriotic poems is manifested in that his patriotic passion is couched in his admiration for t.

Existence and Uniqueness of Global Solutions of a Free Boundary Problem Modeling Tumor Growth;

Existence and uniqueness of global strong solutions of the initial boundary value problem for a class of systems of reaction-diffusion equations in biophysics;

Research on the existence and uniqueness of a differential equation positive solution;

Existence,Uniqueness and Asymptotic Behavior of Global Solutions for Verhulst s Population Mathematical Models;

The unique of inverse eigenvalue problem for a symmetric matrix;

The Exitence and Uniqueness of Strong Solution of Forest Evolution System and the Stability;

The unicity of Sharkovskii-series(S-series);

Unicity theorem of derivative share polynomial;

On the Unicity Theorem for Class Q Meromorphic Functions;

An n×n sign pattern matrix A is a unique inertia pattern, if all matrices with sign pattern A have the same inertia.

The “Non-uniqueness” of Shadow Prices in Linear Programming;

By discussing how to distinct the non-uniqueness of ordinary differential equation starting value,and prompting the result,this essay has obtained the non-uniqueness distinction principle of difference differential equation.