Search

Your search keyword '"Lee, Sun"' showing total 1,294 results
Start Over Author "Lee, Sun" Publisher elsevier b.v.
1,294 results on '"Lee, Sun"'

47. Companion-based multi-level finite element method for computing multiple solutions of nonlinear differential equations.

Author

Hao, Wenrui, Lee, Sun, and Lee, Young Ju

Subjects
*NONLINEAR differential equations, *FINITE element method, *ELLIPTIC equations, *NONLINEAR equations, *QUANTUM mechanics, *ERROR analysis in mathematics
Abstract

The utilization of nonlinear differential equations has resulted in remarkable progress across various scientific domains, including physics, biology, ecology, and quantum mechanics. Nonetheless, obtaining multiple solutions for nonlinear differential equations can pose considerable challenges, particularly when it is difficult to find suitable initial guesses. To address this issue, we propose a pioneering approach known as the Companion-Based Multilevel Finite Element Method (CBMFEM). This novel technique efficiently and accurately generates multiple initial guesses for solving nonlinear elliptic semi-linear equations containing polynomial nonlinear terms through the use of finite element methods with conforming elements. As a theoretical foundation of CBMFEM, we present an appropriate and new concept of the isolated solution to the nonlinear elliptic equations with multiple solutions. The newly introduced concept is used to establish the inf-sup condition for the linearized equation around the isolated solution. Furthermore, it is crucially used to derive a theoretical error analysis of finite element methods for nonlinear elliptic equations with multiple solutions. A number of numerical results obtained using CBMFEM are then presented and compared with a traditional method. These not only show the CBMFEM's superiority, but also support our theoretical analysis. Additionally, these results showcase the effectiveness and potential of our proposed method in tackling the challenges associated with multiple solutions in nonlinear differential equations with different types of boundary conditions. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

48. Effect of Proton Pump Inhibitor on the Outcome of Laryngeal Microsurgery in Patients With Vocal Fold Mucosal Disease With Reflux Symptoms.

Author

Bang, Je Ho, Lee, Sun Gyu, Kwon, Ki Jin, Lee, Seul Ah, Eun, Young-Gyu, and Lee, Young Chan

Abstract

To evaluate the effect of proton pump inhibitor (PPI) after laryngeal microsurgery (LMS) in patients with benign vocal fold (VF) mucosal disease and in patients with overt reflux symptom according to subjective and objective voice assessment. The improvement of voice handicap index-10 (VHI-10) score, reflux symptom index (RSI) score, grade, roughness, breathiness, asthenia, and strain (GRBAS) score, Jitter, Shimmer, noise to harmonics ratio (NHR), maximum phonation time of acoustic voice analysis A total of 47 patients (PPI group [ n = 24] and non-PPI group [ n = 23]) completed the study. The scores for VHI-10, RSI, GRBAS, and acoustic parameters significantly improved in both groups after surgery. In the subgroup analysis of patients with overt reflux symptoms (RSI ≥ 13; non-PPI group [ n = 12], PPI group [ n = 15]), significant between-group differences were observed in terms of the improvement in NHR and the strain factor. Postoperative PPI administration in patients with VF benign mucosal disease with reflux symptoms might improve subjective and objective voice outcomes after LMS. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results