• Communications of the Korean Mathematical Society
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• v.37 no.3
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• pp.839-849
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• 2022

In this paper we consider a condition on the Ricci curvature involving vector fields which enabled us to achieve new results for volume comparison and Laplacian comparison. These results in special case obtained with considering volume non-collapsing condition. Also, by applying this condition we get new results of volume comparison for almost Ricci solitons.

• Nonlinear Functional Analysis and Applications
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• v.26 no.1
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• pp.177-195
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• 2021

In this paper, we introduce the modification of a generalized (Ψ, L)-weak contraction and we prove some coincidence point results for self-mappings G, T and S, and some fixed point results for some maps by using a (c)-comparison function and a comparison function in the sense of a b-metric space.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.233-240
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• 2018

In this study, variables were constructed based on prior research to examine the impact of information system quality (information quality, system quality, service quality), customer value and satisfaction in hotel comparison site. The samples consist of 205 survey data drawn from hotel comparison site users. The collected data were analyzed by SPSS 24.0 and AMOS 21.0. According to results of the reliability and validity test, all were found reliable, and all items were included. The results are as follows: first, Among the information system quality (information quality, system quality, and service quality) of the hotel comparison site, the information quality and service quality have positive effects on customer value. Second, the information system quality(information quality, system quality, and service quality) of the hotel comparison site has a positive effect on customer satisfaction. Third, the customer value of the hotel comparison site has a positive effect on customer satisfaction.

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.539-552
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• 2000

In this paper, we established the general comparison principles for IVP of impulsive differential equations with time variables, which strictly extend and improve the precious comparison results obtained by V. Lakes. et.al . and S.K.Kaul([3]-[7]). Whit the general comparison results, we constructed the monotone iterative sequences of solution for IVP of such equations which converges the maximal and minimal and minimal solutions , respectively.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.238-248
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• 2020

This study examines the feelings of positivity and negativity generated through upward social comparison and explores the impact of the results of the emotions on SNS users' posting behavior. In particular, this study aims to systematically identify the influence of upward social comparison on SNS followers and uploaders' SNS usage behavior and the structural principle of social network circulation in which followers become uploaders again. According to the analysis, interaction-oriented followers made negative upward social comparison and positive upward social comparison, while negative upward social comparison reduced the publication of independence tendency. However, positive upward social comparison has been shown to increase both independent and interactive postings. The results of this study are meaningful in that SNS has expanded the results of prior studies, in which social comparison theories were biased toward negative upward comparisons, to positive upward comparisons. In addition, this study suggested a practical strategy for SNS platform operators on how SNS users would not deviate from other platforms.

• Journal of applied mathematics & informatics
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• v.33 no.1_2
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• pp.193-201
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• 2015

In this paper, we present preconditioned generalized accelerated overrelaxation (GAOR) methods for solving weighted linear least square problems. We compare the spectral radii of the iteration matrices of the preconditioned and the original methods. The comparison results show that the preconditioned GAOR methods converge faster than the GAOR method whenever the GAOR method is convergent. Finally, we give a numerical example to confirm our theoretical results.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.15-19
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• 2003

The Total Least Squares (TLS) method is introduced in comparison with the conventional Least Squares (LS) method. The principles and mathematical models for both methods are summarized and the comparison results from their applications to a simple geometric example, fitting a straight line to a set of 2D points are presented. As conceptually reasoned, the results clearly indicate that LS is more susceptible of producing wrong parameters with worse precision rather than TLS. For many applications in surveying, can adjustment computation and parameter estimation based on TLS provide better results.

• Communications of the Korean Mathematical Society
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• v.34 no.2
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• pp.657-670
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• 2019

In this paper, we consider the preconditioned iterative methods for solving linear complementarity problem associated with an M-matrix. Based on the generalized Gunawardena's preconditioner, two preconditioned SSOR methods for solving the linear complementarity problem are proposed. The convergence of the proposed methods are analyzed, and the comparison results are derived. The comparison results showed that preconditioned SSOR methods accelerate the convergent rate of the original SSOR method. Numerical examples are used to illustrate the theoretical results.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.4
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• pp.788-800
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• 2002

Aging is characterized by an age-dependent reduction in bone density. Pronounced bone loss by postmenopausal estrogen deficiency induces a bad effect on dynamic balance of bone metabolism. When the bone density is reduced to the level below the fracture threshold, the risk for fracture is greatly increased. The purpose of this study is to examine what are the effects of the Yuklinzu(YLZ: 毓麟珠) on the ovariectomized rat model of postmenopausal osteoporosis. The results of the experiment are as follows: Body weight in control group showed significant increase in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum albumin in control group showed significant decrease in comparison with sham. That in YLZ-treated was slightly decreased in comparison with control. The level of serum ALP activity in control group showed significant increase in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum phosphorous in control group showed significant increase in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum calcium in control group showed no change in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum GOT in control group showed no change in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. The level of serum GPT did not significant change among the three groups. The level of serum estrogen in control group showed slightly increased in comparison with sham, but that in YLZ-treated showed no change in comparison with control. The level of serum T3 in control group showed no change in comparison with sham, and that in YLZ-treated showed no change in comparison with control. The level of serum T4 in control group showed significant increase in comparison with sham, but that in YLZ-treated was significantly decreased in comparison with control. Mechanical strength of the femur neck in control group showed significant decrease in comparison with sham. That in YLZ-treated showed slightly increased in comparison with control. Trabecular bone area as well as trabecular thickness in control group showed significant decrease in comparison with sham. Those in YLZ-treated showed significant increase in comparison with control. Trabecular number and did not significant change among the three groups. Trabecular separation only in YLZ-treated showed significant decrease in comparison with control. Osteoclast number and oseoblast surface in control group showed significant increase in comparison with sham. Those in YLZ-treated showed slightly decreased in comparison with control. According to the above these results, YLZ has shown to be capable of preventing and curing osteoporosis caused by old-aged and postmenopause.

• Communications of the Korean Mathematical Society
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• v.27 no.1
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• pp.207-215
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• 2012

In this paper, we provide comparison results of several types of the preconditioned Gauss-Seidel methods for solving a linear system whose coefficient matrix is a Z-matrix. Lastly, numerical results are presented to illustrate the theoretical results.