• East Asian mathematical journal
• /
• v.29 no.1
• /
• pp.23-37
• /
• 2013

The purpose of this paper is to study an implicit iteration process with errors and establish weak and strong convergence theorems to converge to common fixed points for a finite family of generalized asymptotically quasi-nonexpansive mappings in the framework of uniformly convex Banach spaces. Our results extend, improve and generalize some known results from the existing literature.

• The Pure and Applied Mathematics
• /
• v.17 no.4
• /
• pp.307-319
• /
• 2010

We provide a new semilocal convergence analysis of the Gauss-Newton method (GNM) for solving nonlinear equation in the Euclidean space. Using our new idea of recurrent functions, and a combination of center-Lipschitz, Lipschitz conditions, we provide under the same or weaker hypotheses than before [7]-[13], a tighter convergence analysis. The results can be extented in case outer or generalized inverses are used. Numerical examples are also provided to show that our results apply, where others fail [7]-[13].

• Korean Journal of Mathematics
• /
• v.32 no.1
• /
• pp.109-120
• /
• 2024

The aim of this research is to describe lacunary ∆^m-statistically convergent sequences with respect to metrics on generalised metric spaces (g-metric spaces) and to look into the fundamental characteristics of this statistical form of convergence. Also, the relationship between strong summability and lacunary ∆^m-statistical convergence in g-metric space is established at the end.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.8
• /
• pp.8-17
• /
• 2005

It is well known that preconditioning methods are efficient for convergence acceleration in the compressible low Mach number flows. In this study, the original Euler equations and three differently nondimensionalized preconditioning methods are implemented in two dimensional inviscid bump flows using the 3rd order MUSCL and DADI schemes as numerical flux discretization and time integration, respectively. The multigrid and local time stepping methods are also used to accelerate the convergence. The test case indicates that a properly modified local preconditioning technique involving concepts of a global preconditioning allows Mach number independent convergence. Besides, an asymptotic analysis for properties of preconditioning methods is added.

• Journal of applied mathematics & informatics
• /
• v.8 no.2
• /
• pp.345-360
• /
• 2001

Affine invariant sufficient conditions are given for two local convergence theorems involving inexact Newton-like methods. The first uses conditions on the first Frechet-derivative whereas the second theorem employs hypotheses on the mth(m≥2 an integer). Radius of convergence as well as rate of convergence results are derived. Results involving superlinear convergence and known to be true for inexact Newton methods are extended here. Moreover, we show that under hypotheses on the mth Frechet-derivative our radius of convergence can sometimes be larger than the corresponding one in [10]. This allows a wider choice for the initial guess. A numerical example is also provided to show that our radius of convergence is larger than the one in [10].

• Journal of applied mathematics & informatics
• /
• v.6 no.2
• /
• pp.393-406
• /
• 1999

Affine invariant sufficient conditions are given for two local convergence theorems involving inexact Newton-like methods. The first uses conditions on the first Frechet-derivative whereas the second theorem employs hypotheses on the second. Radius of con-vergence as well as rate of convergence results are derived. Results involving superlinear convergence and known to be true for inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivation our radius of convergence results are derived. Results involving superlinear convergence and known to be true or inexact Newton methods are extended here. Moreover we show that under hypotheses on the second Frechet-derivative our radius of conver-gence is larger than the corresponding one in [10]. This allows a wider choice for the initial guess. A numerical example is also pro-vided to show that our radius of convergence is larger then the one in [10].

• Design Convergence Study
• /
• v.17 no.6
• /
• pp.127-143
• /
• 2018

Although women's status in society have been improving, the existing space for women's main activities is still perceived as limited in scope. In this respect, this study analyzes the domestic literature on women's space and discusses the space for women with intent to gain some implications for further studies on space associated with women. Articles on women's space were sub-classified in light of keywords, years of publication, sites, purposes, methods and journal categories, followed by network and frequency analyses. In addition, focus group interview was conducted to explore a new orientation for further studies. The degree centrality was found high in such keywords as 'women's clinics', 'CPTED', 'women-friendly cities' and 'femininity'. In addition, there is a paucity of studies on women's space. Recent studies have diversified the scope of women's space. At the same time, macroscopic 'urban' approaches to women's space have lately been emerging. Finally, the focus group interview on women's space highlighted the needs to further studies about 'femininity, 'maternity', and 'gender equality' in space, and 'safe environment'.

• Journal of the Ergonomics Society of Korea
• /
• v.33 no.2
• /
• pp.155-165
• /
• 2014

Objective: The aim of this study is to develop an office chair enabling to keep working at reclined sitting posture. Background: Sedentary workers are supposed to change the posture frequently during long hours of sitting. A reclined sitting position has been recommended to reduce disc pressure. But slumped sitting posture caused by the buttock sliding forward without any adjustment of back reclining is commonly observed. The worker seems to have tendency to change the sitting posture maintaining working condition. We assumed the reason to be their hands movement away from the working space when tilting backward. Method: Slide mechanism allowing seat to move forward was designed to maintain the hand position in working space during reclining. A prototype was manufactured and tilting motion was analyzed using motion capture system. Four experiment chairs were tested including the manufactured prototype chair and three other commercial chairs. Results: A backward movements of the hand position were 13.0mm, 101.7mm, 156.1mm and 139.3mm at the prototype chair, compared to chair B, chair C and chair D, respectively. And the movement was remarkably small at the prototype chair. Conclusion: The developed seat sliding chair allows back tilting maintaining hand position at working space. We expect the user tilting back more often than normal tilting chair during seated work. But further investigation is required to figure out the effectiveness of the developed chair using prolonged working hours. Application: The developed office chair directly affects commercialization.

• Journal of the Korea Convergence Society
• /
• v.6 no.2
• /
• pp.37-42
• /
• 2015

Nowadays, as the environmental pollution becomes severe on the earth, the water resource which can be used practically is dried up because of the natural disaster. And so, this is the time to be necessary to have the method for saving the water resource. This study investigates the distributions of velocity and temperature by the flow analysis inside the faucet models for bathroom. Model 3 has the most uniform distribution of temperature after mixing among all models. As model 3 has the smallest velocity distribution and the biggest space to mix by comparing the other models, it is seen to have the most influence on the discharged velocity of water and save the water. As the space of various configuration inside faucet model for bathroom is made by using the result of this study, it is thought to utilize at the development of this model in which more mixing becomes and the water can be saved. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.3
• /
• pp.1-9
• /
• 2004

This study concentrates on the upwind schemes for convergence acceleration of the multigrid method for the Navier-Stokes equations. Comparative study of the upwind schemes in the Fourier space has been performed to identify why the second-order upwind scheme with enlarged stencil can be preconditioned better than the classical second-order upwind scheme. The full-coarsening multigrid method with implicit preconditioned multistage scheme has been implemented for verification of analysis. Numerical simulations on the inviscid and turbulent flows with the Spalart-Allmaras turbulent model have been performed. The results showed consistent trend with the analysis.