We give an easy proof that ${\phi}(z)=\frac{z^2_1}{1-z^2_2}$ induces the bounded composition operator $C_{\phi}:\mathcal{B}{\rightarrow}{\bigcap}H^p(B_2)$ defined by $C_{\phi}f=f\;o\;{\phi}$.

In this paper we show fixed point theorems related with the diameter of orbit on metric spaces. The results presented in this paper extend, improve and unify the results of $Heged\"{u}s$ [1], Kim, Kim, Leem and Ume [2], Kim and Leem [3], Ohta and Nikaido [4] and $Taskovi\'{c}$ [5].

We give nine necessary and sufficient conditions for a metric space to be complete.

In this paper, we shall give new characterizations of best approximation element in linear 2-normed spaces in terms of bounded linear 2-functionals and 2-hyperplanes.

The purpose of the present paper is to introduce a new class $\mathcal{P}_{n,p}(\alpha)$ of analytic functions defined by a multiplier transformation and to investigate some properties for the class $\mathcal{P}_{n,p}(\alpha)$.Furthermore, we consider an integral of functions belonging to the class $\mathcal{P}_{n,p}(\alpha)$.

Since the time of Euler, there have been many proofs giving the value of $\zeta(2n)$. We also give an evaluation of $\zeta(2n)$ by analyzing the generating function of Bernoulli numbers.

We study some properties of N-dichotomy for evolutionary process and generalize the theory of the uniform N-equistability using these properties.

The problem of solution uniqueness to the task of determining unknown parameters of mathematical models from input-output observations is studied. This problem is known as structural identifiability problem. We offer a new approach for testing structural identifiability of linear state space models. The approach compares favorably with numerous methods proposed by other authors for two main reasons. First, it is formulated in obvious mathematical form. Secondly, the method does not involve unfeasible symbolic computations and thus allows to test identifiability of large-scale models. In case of non-identifiability, when there is a set of solutions to the task, we offer a method of computing functions of the unknown parameters which can be determined uniquely from input-output observations and later used as new parameters of the model. Such functions are called parametric functions capable of estimation. To develop the method of computation of these functions we use Lie group transformation theory. Illustrative example is given to demonstrate applicability of presented methods.

In this paper, we study the duality theory of nonlinear parabolic systems. The main objective is to prove the duality theorem under general conditions within an infinite-dimensional framework. As an application, an example is given.

The authors apply the theory of multiple Gamma functions, which was recently revived in the study of the determinants of the Laplacians, in order to present a class of closed-form evaluations of series involving the Zeta function by appealing only to the definitions of the double and triple Gamma functions.

In this paper we consider the optimal control problem of both operators and parameters for nonlinear hyperbolic systems. For the identification problem, we show that for every value of the parameter and operators, the optimal control problem has a solution. Moreover we obtain the necessary conditions of optimality for the optimal control problem on the system.

We evaluate the dual quermassintegrals of $\gamma$-equichordal bodies and obtain the lower bound for the volume product of p-centroid body in $E^2$.

This paper is to show that a submanifold of codimension 2 of an odd-dimensional sphere with an almost contact metric structure is an intersection of a complex cone with generator as a normal vector and a sphere.

We give a generalization of the Bateman's polynomial $F_n(x)$ and also give two generating functions for the generalized polynomial.