Elmira ABDILDAYEVA

Proceedings Paper | 2024 | AIP Conference Proceedings3085 ( 1 )

The paper investigates the solvability of a boundary value problem in the control of an oscillatory process described by control in partial derivatives of the first order. It has been established that there are an infinite set of controls, as solutions to the system of nonlinear Fredholm integral equations of the first kind, each of which transfers the controlled process from the initial state to the final specified state in a specified time. Sufficient conditions for the existence of a nonlinear optimization solution are found.

Asan ÖMÜRALİEV | Ella ABILAYEVA

Proceedings Paper | 2017 | AIP Conference Proceedings1880 ( 1 )

The aim of this paper is to construct regularized asymptotics of the solution of a singularly perturbed parabolic problem when the limit operator has not range and with rapidly oscillating free term, its derivative of the phase vanishes at finite points. The vanishing of the first derivative of the phase of the free term induces transition layers. It is shown that the asymptotic solution of the problem contains parabolic, inner, corner and rapidly oscillating boundary-layer functions. Corner boundary-layer functions have two components: the first component is described by the product of parabolic boundary layer and boundary layer fu . . .nctions, which have a rapidly oscillating nature of the change, and the second component is described by the product of the inner and parabolic boundary layer functions More less

Avıt ASANOV

Article | 2021 | AIP Advances11 ( 7 )

In this framework, the necessary and sufficient conditions for the existence and uniqueness of the second-order linear Fredholm-Stieltjes-integral equations, u(x) = lambda integral(b)(a) K(x, y) u(y) dg(y) + f(x), x is an element of[a, b], are thoroughly derived. Moreover, instead of approximating the integral equation by different numbers of partition n, the optimal number n for the given error tolerance is established. The system of equations is implemented in MAPLE for the Runge method. An efficient scheme is proposed for second-order integral equations. The solution has been compared with an exact and closed-form solution for li . . .mited cases. (c) 2021 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/) More less

Elmira ABDILDAYEVA

Proceedings Paper | 2018 | AIP Conference Proceedings1997 ( 1-UNSP 020070-1 )

Nonlinear optimization problem is investigated for oscillation processes described by Fredholm integro-differential equations in partial derivatives when the function of the external source nonlinearly depends on vector distributed control. It is established that, the optimal control procedure is greatly simplified with vector control. Algorithm is developed for constructing a complete solution of the nonlinear optimization problem.

Mehmet ERTUĞRUL

Article | 2022 | APL Materials10 ( 10 )

Narrowband photodetectors have broad application prospects in many fields where only a range of specific wavelengths of light needs tobe detected. However, the current narrowband detectors have some disadvantages, such as the integration is difficult, the full width at half-maximum is not narrow enough, and the spectral rejection ratio is not ideal (< 20). Here, we present a self-filtering photodetector basedon MAPbX3single crystals with a very narrow spectral response and a full width of 15 nm at half maximum. It also shows a high responsivity (similar to 100 mA/W) and a high spectral rejection ratio (similar to 300). What is more, . . . the response spectrum can be tuned within a certain range(from 440 to 560 nm) by varying the halide composition and thus its bandgap. This provides a new design paradigm for self-filtering narrowband photodetectors. (C) 2022 Author(s). Keyword: narrowband systems; epitaxy; polymers; scanning electron microscopy; perovskites; photodetectors; quantum efficienc More less

Dağıstan ŞİMŞEK

Proceedings Paper | 2017 | AIP Conference Proceedings1880 ( 1 )

In Simsek's paper it was introduced a concept of soft cone metric space via soft elements and some fixed point theorems in soft cone metric space were provided. In this work, we examine topological structures such as open ball, soft neighbourhood and soft open set in soft metric spaces and their some properties, and prove that every soft cone metric space under some condition is a soft topological space according to elementary operations on soft sets.

Dağıstan ŞİMŞEK | Burak OĞUL

Proceedings Paper | 2017 | AIP Conference Proceedings1880 ( 1 )

In this paper a solution of the following difference equation xn+1=xn-111+xn-2xn-5xn-8 was investigated, where x-11, x-10, ..., x-2, x-1, x0 ∈ (0, ∞).

Elmira ABDILDAYEVA

Proceedings Paper | 2017 | AIP Conference Proceedings1880 ( 1 )

In the paper we investigate the optimal control problem for elastic oscillation under multipoint influences of external forces when oscillation process is described by Fredholm integro-differential equation. Sufficient conditions for unique solvability of nonlinear optimization problem were found and the algorithm for constructing complete solution to this problem was developed.

Elmira ABDILDAYEVA

Proceedings Paper | 2019 | AIP Conference Proceedings2183 ( 1-UNSP 070005 )

In this paper, the dynamics of convergence rate is investigated for the approximations depending on the changes of the stiffness coefficient of the elastic fixation. The results of the numerical analysis show that with increasing of stiffness coefficient (parameter alpha) of the elastic fixation the radius of convergence of Neumann series increases, and the convergence rate of the approximations to the exact solution accelerates.

Elmira ABDILDAYEVA

Proceedings Paper | 2023 | AIP Conference Proceedings2879 ( 1 )

As it is well known, there are various constructions of the R-compactification (Hewitt real compactification) of a uniform space [13], [15]. In this work we propose a new construction of the R-compactification (Hewitt real compactification) of a uniform space. Keyword: A0-boundedness; R-compactification; R-completeness.; R-extension

Elmira ABDILDAYEVA

Proceedings Paper | 2021 | AIP Conference Proceedings2325 ( 1 )

The article explores general nonlinear equations with a parameter. Sufficient conditions for the existence of a solution of nonlinear integral equations in the form of the sum of two functions for the individual values of the parameter are found.

Mehmet ERTUĞRUL

Article | 2023 | APL Materials11 ( 7 )

New fluorescent materials with a low cost, hypotoxicity, and concealment are desired for the application of anti-counterfeiting. Herein, we report a CsCu2I3@Cs3Cu2I5 composite with a triple-mode photoluminescence (PL) feature by simply adjusting the excitation wavelengths, which are ascribed to the multiple excited states of different phases in the CsCu2I3@Cs3Cu2I5 composite. The broadband emission and high quantum yield (∼51) of the composite originate from the structure-oriented self-trapped excitons effect of Cs3Cu2I5 and CsCu2I3 phases. Moreover, the incorporation of polyethylene oxide (PEO) into this composite improves the stab . . .ility of CsCu2I3@Cs3Cu2I5@PEO against harsh environments. The CsCu2I3@Cs3Cu2I5@PEO composite has a slight decay of ∼5 of its initial PL intensity and only a 3.5 shift of the corresponding color coordinate after 30 days of storage. More importantly, its initial PL intensity shows only 10.3 decay under ultraviolet exposure for 200 h. Our work provides a promising approach to design materials for advanced anti-counterfeiting applications. Keyword: excitons; fluorescent materials; photoluminescence; band emission; solid state chemistry; photochemical reaction More less