• 대한수학회보
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• 제61권3호
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• pp.699-715
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• 2024

We study the Riemann problem for the pressureless Euler system with the source term depending on the time. By means of the variable substitution, two kinds of Riemann solutions including deltashock and vacuum are constructed. The generalized Rankine-Hugoniot relation and entropy condition of the delta-shock are clarified. Because of the source term, the Riemann solutions are non-self-similar. Moreover, we propose a time-dependent viscous system to show all of the existence, uniqueness and stability of solutions involving the delta-shock by the vanishing viscosity method.

• 한국측량학회지
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• 제32권3호
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• pp.225-231
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• 2014

When a spatial regression model that uses kernel density values as a dependent variable is applied to retail business data, a unique model cannot be selected because kernel density values change following kernel bandwidths. To overcome this problem, this paper suggests how to use the point pattern analysis, especially the L-index to select a unique spatial regression model. In this study, kernel density values of retail business are computed by the bandwidth, the distance of the maximum L-index and used as the dependent variable of spatial regression model. To test this procedure, we apply it to meeting room business data in Seoul, Korea. As a result, a spatial error model (SEM) is selected between two popular spatial regression models, a spatial lag model and a spatial error model. Also, a unique SEM based on the real distribution of retail business is selected. We confirm that there is a trade-off between the goodness of fit of the SEM and the real distribution of meeting room business over the bandwidth of maximum L-index.

• 한국해안해양공학회지
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• 제19권6호
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• pp.521-532
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• 2007

완경사 파랑식의 유도에 Galerkin방법을 사용하여 수심 의존함수에 대한 Sturm-Liouville 미분식을 엄밀하게 구성하였다. 구한 방정식의 종속변수에 대한 전형적인 변수변환으로 수심, 해저경사 그리고 해저곡률에 대한 항들로 구성된 변형 Helmholtz식을 얻었다. 수치실험을 통해 이 항들이 지형에 의한 파랑변형에 주요한 역할을 보이고 이들의 상대적인 크기에 의해 수정 완경사 파랑식(MMSE)에 비해 완경사 파랑식(MSE)의 적용성이 제한됨을 입증하였다.

• Journal of Preventive Medicine and Public Health
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• 제52권3호
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• pp.154-160
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• 2019

Objectives: Stillbirth is a common adverse pregnancy outcome that represents a distressing and traumatic event for women and their partners. The aim of this study was to identify factors associated with stillbirth in ever-pregnant women in Nepal. Methods: This study utilized the individual women's dataset from the Nepal Demographic and Health Survey, conducted in 2016. The dependent variable of interest was whether women had at least 1 stillbirth during their lifetime. The associations between independent variables and the dependent variable of the study were analyzed using a multiple logistic regression model. Results: Among 8918 ever-pregnant women aged 15-49 years, 488 had experienced at least 1 stillbirth during their lifetime, representing 5.5% of the total. After adjusting each factor for the confounding effects of other factors, maternal age, maternal education, place of residence, and sub-region remained significantly associated with having experienced stillbirth. Conclusions: Stillbirth continues to be a major problem among women, especially those with higher maternal age, those who are illiterate, and residents of certain geographical regions. To minimize stillbirth in Nepal, plans and policies should be focused on women with low education levels and residents of rural areas, especially in the western mountain and far-western hill regions.

• 동아시아경상학회지
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• 제11권2호
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• pp.81-89
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• 2023

Purpose - Several previous studies have been completed on oriental art therapy's impact on problem-solving and innovation in business workers. However, there is a definite research gap in how it reduces stress within the impacts oriental art therapy on business workers. Therefore, this research will be significant in finding out what oriental art therapy has reduced work-related stress and increased satisfaction among business workers. Research design, data, and methodology - For this research, the dependent variable was the significance of oriental art therapy, and the dependent variable was reducing work-related stress and increasing the satisfaction of business workers. The study's hypothesis was oriental art therapy reduces work-related stress and increases the satisfaction of business workers. A quantitative quasi-experimental pilot design was the most appropriate for this study. Result - This research figured out that the art therapy affect significantly reducing work-related stress among business workers, removing the level of anxiety, improving employee's feeling, and so leading to improvement in communication and collaboration each other in the organization. Conclusion - The results of the investigation imply that oriental art therapy can significantly improve the workers' satisfaction in a business. The research shows how successfully some of the interventions introduced in the medical supply company fully transformed the workers' lives.

• 한국지구과학회지
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• 제24권7호
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• pp.604-613
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• 2003

이 연구의 목적은 메타전략 활동이 중학교 1학년 학생들의 변인통제 능력 향상에 효과가 있는지를 조사하는 것이었다. 이를 위해 대구광역시내 1개 중학교 1학년 3학급을 각각 메타전략 활동집단, 문제풀이 활동집단 및 통제집단으로 선정하였다. 처치활동으로 메타전략 활동집단에게는 매회 15분씩 총 4회에 걸쳐 어느 한 특정 상황에서 변인통제전략에 대한 컨트롤, 모니터 및 평가 등의 활동이 요구되는 자료를 투입하였다. 문제풀이 활동집단에게는 메타전략 활동집단과 같은 방법으로 활동자료를 투입하였으나 그 내용은 다양한 상황하에서 여러 가지 변인통제 문제들을 해결하는 활동으로 구성되었다. 이 연구의 결과는 다음과 같다. 첫째, 메타전략 활동집단은 문제풀이 활동집단 및 통제집단보다 변인통제 능력 향상에 효과적이며(p<.05) , 그 효과는 지속적이었다(p<.01). 문제풀이 활동집단의 경우, 통제집단보다 효과는 있었으나(p<.05) 지속 효과는 없었다. 둘째, 변인통제 능력의 요소별 발달 정도를 집단간 비교 분석 결과, 메타전략 활동집단이 문제풀이 활동집단보다 고정변인 찾기 능력에서 통계적으로 유의미한 차이를 보인 반면(p<.01), 독립변인 찾기 능력에서는 통계적으로 유의미한 차이가 없었으며, 종속변인 찾기 능력 발달로의 전이의 효과는 없었다. 따라서 이상의 연구 결과를 종합해 볼 때, 과학탐구능력 중의 변인통제 능력을 향상시키기 위해서는 다양한 문제를 해결하도록 하는 활동 못지 않게 한 문제에 대해 깊이 생각해보는 메타전략 활동이 효과가 있음을 알 수 있었다.

• 공학교육연구
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• 제22권3호
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• pp.32-40
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• 2019

This paper deals with the effects of teamwork competence on problem solving ability through the mediating effect of creative personality for the engineering students. For this purpose, a regression-based statistical mediation analysis has been performed for a simple mediation model in which teamwork competence and problem solving ability were treated as independent and dependent variables respectively, and creative personality was included as a mediation variable. The analysis results showed that the teamwork competence has direct effect on the problem solving ability as well as indirect effect through the creative personality. This result implies that the problem solving ability can be improved directly by improving the teamwork competence, and moreover, it can be further improved indirectly or through the mediation effect by improving the creative personality. Thus, in order to develop excellent problem solving ability, it is necessary to form team members in a balanced way between teamwork competence and creative personality in the team-based learning.

• 대한한의학방제학회지
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• 제29권4호
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• pp.253-266
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• 2021

Objective : This is to analyze the factors affecting the satisfaction of curriculum at korean medicine college and suggest the direction of the curriculum reformation of korean medicine colleges. Method : The collected data were conducted multiple linear regression analysis using the SPSS ver.26 statistical program, using 'curriculum satisfaction' as a dependent variable after analyzing the frequency of each variable. Result : The average score for curriculum satisfaction at Korean Medicine college was 2.87 points, which was relatively low. The factors affecting the satisfaction of the curriculum were 'A favorable impression of Korean Medicine College of W University' β=0.351(p<.001), 'connectivity between major subjects' β=0.312(p<.001), 'duplex between major subjects' β=-0.163(p<.05), 'recognition of the importance of Chinese characters' β=0.114(p<.0.5). Conclusion : The curriculum of Korean Medicine College should first, be organized to allow students to be proud of themselves, second, the goal of education should set goals optimized for job competency, third, the content of learning should be consisted of student led problem based learning, fourth, the link between major subjects should be intensified, fifth, the clinical practice time should be expanded significantly and lastly the assessment evaluates the performance process.

• Structural Engineering and Mechanics
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• 제23권5호
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• pp.525-542
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• 2006

On the basis of equilibrium equations for static electric and magnetic fields, two unknown functions related to electric and magnetic fields were firstly introduced to rewrite the governing equations, boundary conditions and initial conditions for mechanical field. Then by introducing a dependent variable and a special function satisfying the inhomogeneous mechanical boundary conditions, the governing equation for a new variable with homogeneous mechanical boundary conditions is obtained. By using the separation of variables technique as well as the electric and magnetic boundary conditions, the dynamic problem of a functionally graded magneto-electro-elastic hollow sphere under spherically symmetric deformation is transformed to two Volterra integral equations of the second kind about two unknown functions of time. Cubic Hermite polynomials are adopted to approximate the two undetermined functions at each time subinterval and the recursive formula for solving the integral equations is derived. Transient responses of displacements, stresses, electric and magnetic potentials are completely determined at the end. Numerical results are presented and discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권6호
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• pp.2422-2443
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• 2020

This paper studies a single-user Mobile Edge Computing (MEC) system where mobile device (MD) includes an application consisting of multiple computation components or tasks with dependencies. MD can offload part of each computation-intensive latency-sensitive task to the AP integrated with MEC server. In order to accomplish the application faultlessly, we calculate out the optimal task offloading strategy in a time-division manner for a predetermined execution order under the constraints of limited computation and communication resources. The problem is formulated as an optimization problem that can minimize the energy consumption of mobile device while satisfying the constraints of computation tasks and mobile device resources. The optimization problem is equivalently transformed into solving a nonlinear equation with a linear inequality constraint by leveraging the Lagrange Multiplier method. And the proposed dual Bi-Section Search algorithm Bi-JOTD can efficiently solve the nonlinear equation. In the outer Bi-Section Search, the proposed algorithm searches for the optimal Lagrangian multiplier variable between the lower and upper boundaries. The inner Bi-Section Search achieves the Lagrangian multiplier vector corresponding to a given variable receiving from the outer layer. Numerical results demonstrate that the proposed algorithm has significant performance improvement than other baselines. The novel scheme not only reduces the difficulty of problem solving, but also obtains less energy consumption and better performance.