• Communications of the Korean Mathematical Society
• /
• v.34 no.3
• /
• pp.1015-1027
• /
• 2019

A class of systems of singularly perturbed convection diffusion type equations with integral boundary conditions is considered. A numerical method based on a finite difference scheme on a Shishkin mesh is presented. The suggested method is of almost first order convergence. An error estimate is derived in the discrete maximum norm. Numerical examples are presented to validate the theoretical estimates.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.281.1-281.1
• /
• 2003

Purpose. The purpose of this study was to develop and validate sensitive and specific analytical method for determinination of simvastatin in human plasma by the column-switching high-performance liquid chromatography (HPLC) system with UV detection. Methods. Simvastatin and internal standard were extracted into diethyl ether from plasma. (omitted)

• Korean Journal of Mathematics
• /
• v.29 no.4
• /
• pp.749-763
• /
• 2021

This research article deals with the Mittag-Leffler-Hyers-Ulam stability of linear and impulsive fractional order differential equation which involves the Caputo derivative. The application of the generalized fractional Fourier transform method and fixed point theorem, evaluates the existence, uniqueness and stability of solution that are acquired for the proposed non-linear problems on Lizorkin space. Finally, examples are introduced to validate the outcomes of main result.

• 제어로봇시스템학회:학술대회논문집
• /
• 1989.10a
• /
• pp.733-743
• /
• 1989

This paper deals with the control of system with controlled jump Markov disturbances. A such formulation was used by Boukas to model the planning production and maintenance of a FMS with failure machines. The optimal control problem of systems with controlled jump Markov process is addressed. This problem describes the planning production and preventive maintenance of production systems. The optimality conditions in both cases finite and infinite horizon, are derived. A numerical example is presented to validate the proposed results.

• Korean Journal of Mathematics
• /
• v.31 no.3
• /
• pp.269-294
• /
• 2023

The purpose of this paper is to introduce a new three-step iterative process and show that our iteration scheme is faster than other existing iteration schemes in the literature. We provide a numerical example supported by graphs and tables to validate our proofs. We also prove convergence and stability results for the approximation of fixed points of the contractive-like mapping in the framework of uniformly convex Banach space. In addition, we have established some weak and strong convergence theorems for nonexpansive mappings.

• Nonlinear Functional Analysis and Applications
• /
• v.28 no.3
• /
• pp.851-863
• /
• 2023

We study the appropriate conditions for the findings of uniqueness and existence for a group of boundary value problems for impulsive Ψ-Caputo fractional nonlinear Volterra-Fredholm integro-differential equations (V-FIDEs) with symmetric boundary non-instantaneous conditions in this paper. The findings are based on the fixed point theorem of Krasnoselskii and the Banach contraction principle. Finally, the application is provided to validate our primary findings.

• Communications of the Korean Mathematical Society
• /
• v.38 no.1
• /
• pp.281-298
• /
• 2023

A class of systems of Caputo fractional differential equations with integral boundary conditions is considered. A numerical method based on a finite difference scheme on a uniform mesh is proposed. Supremum norm is used to derive an error estimate which is of order κ − 1, 1 < κ < 2. Numerical examples are given which validate our theoretical results.

• The Pure and Applied Mathematics
• /
• v.29 no.1
• /
• pp.1-17
• /
• 2022

We establish a common n-tupled fixed point theorem for hybrid pair of mappings under generalized Mizoguchi-Takahashi contraction. An example is given to validate our results. We improve, extend and generalize several known results.

• Korean Journal of Mathematics
• /
• v.31 no.4
• /
• pp.391-403
• /
• 2023

In this work, we establish common fixed point results by utilizing a variant of F-contraction in the framework of C^*-algebra valued metric spaces. We utilize E.A. and C.L.R. property possessed by the mappings to prove common fixed point results in the same metric settings. To validate the applicability of these common fixed point results, we provide illustrative examples too.

• Journal of Korean Academy of Nursing
• /
• v.39 no.5
• /
• pp.683-692
• /
• 2009

Purpose: The purpose of this study was to identify cancer-related symptom clusters and to validate the conceptual meanings of the revealed symptom clusters in patients with hepatocellular carcinoma. Methods: This study was a cross-sectional survey and methodological study. Patients with hepatocellular carcinoma (N=194) were recruited from a medical center in Seoul. The 20-item Symptom Checklist was used to assess patients' symptom severity. Selected symptoms were factored using principal-axis factoring with varimax rotation. To validate the revealed symptom clusters, the statistical differences were analyzed by status of patients' performance status, Child-Pugh classification, and mood state among symptom clusters. Results: Fatigue was the most prevalent symptom (97.4%), followed by lack of energy and stomach discomfort. Patients' symptom severity ratings fit a four-factor solution that explained 61.04% of the variance. These four factors were named pain-appetite cluster, fatigue cluster, itching-constipation cluster, and gastrointestinal cluster. The revealed symptom clusters were significantly different for patient performance status (ECOG-PSR), Child-Pugh class, anxiety, and depression. Conclusion: Knowing these symptom clusters may help nurses to understand reasonable mechanisms for the aggregation of symptoms. Efficient symptom management of disease-related and treatment-related symptoms is critical in promoting physical and emotional status in patients with hepatocellular carcinoma.