In recent years, innovation and R&D activities have been one of the most important factors affecting the growth strategies of the companies and their financial performance. However, it is the fundamental elements of sustainable economic growth, innovative activities have strategic decision-making characteristics due to their effects on efficiency and market value. The aim of this paper is to investigate the effects of R&D expenditures on the financial performance of 62 production companies listed in Borsa Istanbul in the period of 2008-2017 by using panel data methods. We used return on assets ...Daha fazlası
In this paper, we investigate the nonlinear problem of the optimal vector control for oscillation processes described by Fredholm integro-differential equations in partial derivatives when function of external sources nonlinearly depend on control parameters. It was found that the system of nonlinear integral equations,which obtained relatively to the components of the optimal vector control, have the property of equal relations. This fact lets us to simplify the procedure of the constructing the solution of the nonlinear optimization problem. We have developed algorithm for constructing the s ...Daha fazlası
The various types of ultrafilter-completeness on zero-sets of uniformly continuous functions are introduced, their properties are studied and characterizations in the category are given.
In this study, we give some estimates on the Nikolskii-type inequalities for complex algebraic polynomials in regions with piecewise smooth curves having exterior and interior zero angles.
This work presents Fe3O4 and AgFe nanoparticles with an average diameter of 25 and 15 nm synthesized by chemical reduction of corresponding salts under a mild condition. Cubic crystal structure and spherical shape of the nanoparticles were studied by X-ray diffraction, Field emission SEM and energy-dispersive spectroscopy analysis. For biomedical applications, the nanoparticles were tested against bacteria E.coli and results revealed AgFe nanoparticles
One of the best methods of waste recycling in the construction sector is to employ it in concrete or mortar preparation. In this study, recycled concrete aggregate and bottom ash were used as aggregates in the mortar. Additionaly, expanded perlite which is a material providing lightness, heat insulation and fire resistance, was also used as aggregate. Calcium aluminate cement was preferred as binder to improve fire resistance. Results were obtained and evaluated in terms of flexural and compressive strength, dry unit weight, water absorption, capillarity, thermal conductivity, thermal resistan ...Daha fazlası
In the paper, exact constants in direct and inverse approximation theorems for functions of several variables are found in the spaces S-p. The equivalence between moduli of smoothness and some K-functionals is also shown in the spaces S-p.
A number of basic properties of R-compact spaces in the category Tych of Tychonoff spaces and their continuous mappings are extended to the category ZUnif of uniform spaces with the special normal bases and their coz-mappings.
Traditionally the Euler method is used for solving systems of linear differential equations. The method is based on the use of eigenvalues of a system's coefficients matrix. Another method to solve those systems is the D'Alembert integrable combination method. In this paper, we present a new method for solving systems of linear differential and difference equations. The main idea of the method is using the coefficients matrix eigenvalues to find integrable combinations of system variables. This method is particularly advantageous when nonhomogeneous systems are considered.
Dağıstan ŞİMŞEK | Peyil Esengul Kızı | Meerim İmaş Kızı
In this paper the solutions of the following difference equation is examined:
x(n+1) = x(n-7)/1 + x(n-3), n = 0, 1, 2, 3, ...
where the initial conditions are positive real numbers.
The Cauchy problem with a rapidly oscillating initial condition for the homogeneous Schrodinger equation was studied in [5]. Continuing the research ideas of this work and [3], in this paper we construct the asymptotic solution to the following mixed problem for the nonstationary Schrodinger equation:
L(h)u ih partial derivative(t)u + h(2)partial derivative(2)(x)u - b(x,t)u = f(x,t) (x,t) is an element of Omega = (0,1) x (0,t],
u vertical bar(t=0) = g(x), u vertical bar(x=0) = u vertical bar(x=1) = 0
where h > 0 is a Planck constant, u = u(x,t,h). b(x,t), f (x,t) is an element of C-infinity ...Daha fazlası