• 한국해양공학회지
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• 제15권2호
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• pp.22-32
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• 2001

The numerical investigation of obliquely incident wave interactions with fully submerged dual buoy/porous-membrane floating breakwaters placed in parallel with spacing is studied based on linear potential theory and Darcy's law. The numerical solutions are obtained by using a discrete-membrane dynamic model and second-kind modified Bessel function distribution over the entire boundaries of fluid regions. First, numerical solutions for an idealized dual submerged system without buoys are obtained. Second, a more practical dual submerged system with membrane tension provided by buoys at its tops is investigated by the multi-domain boundary element method particularly devised for dual buoy/porous-membrane problems with gaps. The velocity potentials of wave motion are coupled with porous-membrane deformation, and solved simultaneously since the boundary condition on porous-membrane is not known in advance. The effects of varying permeability on membranes and wave characteristics are discussed for the optimum design parameters of systems previously studied. The inclusion of permeability on membrane eliminates the resonances that aggravate the breakwater performance. The system is highly efficient when waves generated by the buoys and membranes were mutually canceled and its energy at resonance frequency dissipates through fine pores on membranes.

• 수산경영론집
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• 제34권1호
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• pp.31-44
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• 2003

The purpose of this study is to investigate empirically interaction among the financing decision, investment decision, and profitability by using 41 fisheries corporations in Korea, and to suggest implications of the empirical results for government's financial policy for fisheries corporations. Sample period is 19 years from 1982 till 2000. This analysis method employs the two stage least squares(2SLS) estimation method. From the results of regression analysis by 2SLS estimation method, the adjusted $R^2$ values were high and the overall F values indicated significant. The empirical results of this study are as follows; (1) determinant factors of capital structure model for fisheries are profitability, firm-size, fisheries investment of total asset, and business risk. As pecking order theory explains, the higher is profitability the lower is debt ratio. The larger firm-size, the higher is debt ratio. The higher is fisheries investment of total asset and business risk, the higher is debt ratio. (2) determinant factors of investment model for fisheries are the change of sales, business risk, and debt ratio. These factors have positive relation to fisheries investment of total asset (3) determinant factors of profitability model for fisheries are fisheries investment of total asset and debt ratio. These factors have negative relation to profitability. On the basis of analysis results, on the government's financial policy for fisheries corporations, I suggests that with interest rate reduction, the government should lend more funds to solve the crisis in the financial structure of the fisheries firms

• Interaction and multiscale mechanics
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• 제6권2호
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• pp.137-156
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• 2013

In this paper, a meshfree shell adaptive procedure is developed for the applications in the sheet metal forming simulation. The meshfree shell formulation is based on the first-order shear deformable shell theory and utilizes the degenerated continuum and updated Lagrangian approach for the nonlinear analysis. For the sheet metal forming simulation, an h-type adaptivity based on the meshfree background cells is considered and a geometric error indicator is adopted. The enriched nodes in adaptivity are added to the centroids of the adaptive cells and their shape functions are computed using a first-order generalized meshfree (GMF) convex approximation. The GMF convex approximation provides a smooth and non-negative shape function that vanishes at the boundary, thus the enriched nodes have no influence outside the adapted cells and only the shape functions within the adaptive cells need to be re-computed. Based on this concept, a multi-level refinement procedure is developed which does not require the constraint equations to enforce the compatibility. With this approach the adaptive solution maintains the order of meshfree approximation with least computational cost. Two numerical examples are presented to demonstrate the performance of the proposed method in the adaptive shell analysis.

• Structural Engineering and Mechanics
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• 제25권4호
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• pp.383-403
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• 2007

The contact problem for an elastic layer resting on an elastic half plane is considered according to the theory of elasticity with integral transformation technique. External loads P and Q are transmitted to the layer by means of two dissimilar rigid flat punches. Widths of punches are different and the thickness of the layer is h. All surfaces are frictionless and it is assumed that the layer is subjected to uniform vertical body force due to effect of gravity. The contact along the interface between elastic layer and half plane will be continuous, if the value of load factor, ${\lambda}$, is less than a critical value, ${\lambda}_{cr}$. However, if tensile tractions are not allowed on the interface, for ${\lambda}$ > ${\lambda}_{cr}$ the layer separates from the interface along a certain finite region. First the continuous contact problem is reduced to singular integral equations and solved numerically using appropriate Gauss-Chebyshev integration formulas. Initial separation loads, ${\lambda}_{cr}$, initial separation points, $x_{cr}$, are determined. Also the required distance between the punches to avoid any separation between the punches and the layer is studied and the limit distance between punches that ends interaction of punches, is investigated. Then discontinuous contact problem is formulated in terms of singular integral equations. The numerical results for initial and end points of the separation region, displacements of the region and the contact stress distribution along the interface between elastic layer and half plane is determined for various dimensionless quantities.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1382-1387
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• 2004

From the viewpoint of a macro state, there is no thermal boundary resistance (TBR) at an interface if both surfaces at an interface are perfectly contacted. However, recent molecular dynamics (MD) studies reported that there still exists the TDR at the interface in an ideal epitaxial superlttice. Our previous studies suggested the model to predict the TBR not only quantitatively also qualitatively in superlattices. The suggested model was based on the classical theory of a wave reflection, and provided highly satisfactory results for an engineering purpose. However, it was not the complete model because our previous model was derived by considering only the effects from a mass ratio and a potential ratio of two species. The interaction of two species presented by the Lennard-Jones (L-J) potential is governed by the mutual ratio of the masses, the potential well depths, and the diameters. In this study, we performed the preliminary simulations to investigate the effect resulting from the diameter ratio of two species for the completion of our model and confirmed that it was also a ruling factor to the TBR at an interface in superlattices.

• 대한간호학회지
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• 제28권1호
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• pp.37-46
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• 1998

Recently the concept of 'empowerment' not only attracts attention in the area of management but also is considered as an useful concept in the areas of nursing theory. practice, education, and research. The purpose of this paper is to clarify the meaning of the concept 'empowerment'. More concretely, it is to find the concept that can be applied appropriately to the area of nursing management. This study uses Walter & Avant's(1983) process of concept analysis. The attributes of empowerment based on the concept can be defined concisely as follows : 1. a dynamic and interaction process 2. a partnership which values self and others : power shaving 3. mutual decision-making using resources, opportunities, and authority 4. accept autonomy and responsibility Antecedents of empowerment consist of 1) mutual trust and respect, 2) education and support, 3) participation and commitment. In regard to the consequences of empowerment, it is expected to 1) positive self-esteem, 2) ability to set and reach goals, 3) the promotion of organization's effectiveness and productivity, 4) provide effective and high quality health-care, 5) a sense of hope for the future. The concept of empowerment is certainly believed that it will help future nurses since they needs an integrated technique that can treat acute and chronic patients' nursing, individuals, families, and communities. Therefore. it is necessary to develop the instrument including the defining attributes identified in this study. Also, it is need follow up study of this concept.

• 디지털융복합연구
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• 제13권1호
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• pp.449-454
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• 2015

본 연구는 소셜게임의 사회적 기능과 개발모델에 관한 선행요인과 결과요인 및 개발 모델을 제안 분석하는 것을 목적으로 한다. 따라서 본 연구는 소셜게임 사회적 기능에 영향을 미칠 수 있는 선행변수들을 관련이론 분석과 선행연구를 통해 살펴보고, 소셜게임의 사회적 기능 개발 모델을 제시하고 분석하였다. 소셜게임의 사회적 기능 모델을 정서적 유대감, 개방적커뮤니케이션, 공동체감, 상호작용 집중에서 설명되는 항목들을 구체화하여 사회적 기능 향상 척도를 도출하였고, 다양한 소셜네트워크서비스 및 소셜게임 관련이론을 바탕으로 소셜게임 사회적 기능향상 요소를 입증하여 소셜게임 개발 모델를 제시하였다.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.194-207
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• 2019

This paper is the author's personal experience and interpretation as a student whilst participating in Professor Kyung-Sook Shin's English Literature graduate course, "Literature and Technology II: Feminisms and Digital Humanities," during the 2019 spring semester at Yonsei University, South Korea. Exploring the intersections of literary feminist theory and digital humanities, this paper examines not only the content, but also the methodology and political effects of collaboratively digitally annotating Elizabeth Barrett Browning's epic novel/poem, Aurora Leigh (1856) through the medium, Google Docs. In particular, this paper observes the students' interaction with the digital tools and literature-related pedagogy in two main parts. First, the democratic political nature of classroom culture when creating a new language/code during annotation. Second, the coexistence of cyberspace and the physical classroom space and its effect on time, specifically in the archival of the past, influencing of the future, and the splitting into the present multiverse. From a student's perspective in digital literary annotation, this paper shows that technology could become a way to decolonize and reprogram education to be more inclusive and collaborative.

• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.26-32
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• 2017

Background: Ionizing radiation is known to be harmful to human health. The shielding of ionizing radiation depends on the attenuation which can be achieved by three main rules, i.e. time, distance and absorbing material. Materials and Methods: The mass attenuation coefficient, linear attenuation coefficient, Half Value Layer (HVL) and Tenth Value Layer (TVL) of X-rays (32 keV, 74 keV) and gamma rays (662 keV) are measured in Barium compounds. Results and Discussion: The measured values agree well with the theory. The effective atomic numbers ($Z_{eff}$) and electron density (Ne) of Barium compounds have been computed in the wide energy region 1 keV to 100 GeV using an accurate database of photon-interaction cross sections and the WinXCom program. Conclusion: The mass attenuation coefficient and linear attenuation coefficient for $BaCO_3$ is higher than the $BaCl_2$, $Ba(No_3)_2$ and BaSO4. HVL, TVL and mean free path are lower for $BaCO_3$ than the $BaCl_2$, $Ba(No_3)_2$ and $BaSO_4$. Among the studied barium compounds, $BaCO_3$ is best material for x-ray and gamma shielding.

• Fashion, Industry and Education
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• 제15권1호
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• pp.44-58
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• 2017

The purpose of this research is to explore how Millennials mitigate perceived risks that occur during online apparel purchasing decisions through social interactions based on social learning theory. Also, this research investigates concerns generated from interactions with others when consuming apparel online. An exploratory investigation was undertaken with 78 undergraduate students using an online survey that included open and closed questions. Qualitative data revealed positive relationships between consumers' social interactions and purchases of apparel products online. Specifically, information searches through social interactions with trusted individuals utilizing online channels were found to validate purchasing decisions and alleviate perceived risks with purchasing apparel products online. However, consumers were also concerned with certain interactions due to the lack of credibility regarding reviewers, channels, and conflicting information. These findings provide an insight into millennial consumers' learning processes through consumer-to-consumer interactions in social media environments for apparel purchases. As online and mobile shopping along with consumers' social media usage for interacting continue to increase, these research findings guide retailers how to turn their attention to investing and utilizing these channels to enhance millennial consumers' positive purchasing experiences online.