• 대한수학회논문집
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• 제37권3호
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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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• 제26권1호
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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.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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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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• 제7권2호
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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.

• 한국콘텐츠학회논문지
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• 제20권9호
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• pp.238-248
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• 2020

본 연구는 상향 사회비교를 통해 발생 되는 긍정과 부정의 감정을 균형 있게 살펴보고 발생 된 감정의 결과가 SNS 이용자의 게시 행태에 미치는 영향을 탐구한다. 특히, 본 연구는 상향 사회비교가 SNS의 팔로워와 게시자의 SNS 이용행태에 미치는 영향력과 팔로워가 다시 게시자가 되는 소셜 네트워크 순환의 구조적 원리를 체계적으로 규명해보고자 한다. 분석 결과, 상호작용 성향의 팔로워는 부정적인 상향 사회비교와 긍정적인 상향 사회비교를 하였으며, 부정적인 상향 사회비교는 독립 성향 게시를 감소시키는 것으로 나타났다. 하지만, 긍정적인 상향 사회비교는 독립 성향 게시와 상호작용 성향 게시 모두를 증가시키는 것으로 나타났다. 이러한 본 연구의 결과는 SNS에서 사회비교 이론이 부정적 상향 비교에만 치우쳐져 있던 선행 연구의 결과를 긍정적 상향 비교까지 확장 시켰다는 데 의의가 있다. 더불어, 본 연구는 SNS 플랫폼 운영자들에게 SNS 이용자들이 다른 플랫폼으로 이탈하지 않는 방안에 대한 실무적 전략을 제시하였다.

• Journal of applied mathematics & informatics
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• 제33권1_2호
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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.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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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.

• 대한수학회논문집
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• 제34권2호
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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.

• 동의생리병리학회지
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• 제16권4호
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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.

• 대한수학회논문집
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• 제27권1호
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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.