• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.57-77
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• 1998

Heteroepitaxial $Y_2O_3$ films were grown on a Si(111) substrate by ionized cluster beam deposition(ICBD) in ultra high vacuum, and its qualities such as crystllitnity, film stress, and morphological characteristics were investigated using the various measurement methods. The crystallinity was investigated by x-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED). Interface crystallinity was also examined by Rutherford backscattering spectroscopy(RBS) channeling, transmission electron microscopy(TEM). The stress of the films was measured by RBS channeling and XRD. Surface and interface morphological characteristics were investigated by atomic force microscopy (AFM) and x-ray scattering method. Comparing the interface with the surface characteristics, we can conclude that many defects at the interface region were generated by interface reaction between the yttrium metal and SiO2 layer and by ion beam characteristic such as shallow implantation, so that they influenced the film qualities. The film quality was dominantly depended on the characteristic temperature range. In the temperature range from $500^{\circ}C$ to $600^{\circ}C$, the crystallinity was mainly improved and the surface roughness was drastically decreased. On the other hand, in the temperature range from $600^{\circ}C$ to $700^{\circ}C$, the compressive stress and film density were dominantly increased, and the island size was more decreased. Also the surface morphological shape was transformed from elliptical shape to triangular. The film stress existed dominantly at the interface region due to the defects generation.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.47.3-48
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• 2021

We studied the large scale dynamo process in a system forced by helical magnetic field. The dynamo process is basically nonlinear, but can be linearized with 𝛼&𝛽 coefficients and large scale magnetic field $\bar{B}$. This is very useful to the investigation of solar (stellar) dynamo. A coupled semi-analytic equations based on statistical mechanics are used to investigate the exact evolution of 𝛼&𝛽. This equation set needs only magnetic helicity ${\bar{H}}_M({\equiv}{\langle}{\bar{A}}{\cdot}{\bar{B}}{\rangle},\;{\bar{B}}={\nabla}{\times}{\bar{A}})$ and magnetic energy ${\bar{E}}_M({\equiv}{\langle}{\bar{B}}^2{\rangle}/2)$. They are fundamental physics quantities that can be obtained from the dynamo simulation or observation without any artificial modification or assumption. 𝛼 effect is thought to be related to magnetic field amplification. However, in reality the averaged 𝛼 effect decreases very quickly without a significant contribution to ${\bar{B}}$ field amplification. Conversely, 𝛽 effect contributing to the magnetic diffusion maintains a negative value, which plays a key role in the amplification with Laplacian ∇²(= - k²) for the large scale regime. In addition, negative magnetic diffusion accounts for the attenuation of plasma kinetic energy E_V(= 〈 U² 〉/2) (U: plasma velocity) when the system is saturated. The negative magnetic diffusion is from the interaction of advective term - U • ∇ B from magnetic induction equation and the helical velocity field. In more detail, when 'U' is divided into the poloidal component U_pol and toroidal one U_tor in the absence of reflection symmetry, they interact with - B • ∇ U and - U • ∇ B from ∇ × 〈 U × B 〉 leading to 𝛼 effect and (negative) 𝛽 effect, respectively. We discussed this process using the theoretical method and intuitive field structure model supported by the simulation result.

• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.271-280
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• 2022

The purpose of this study is to investigate the concept of composition of educational service quality through two integrated research methods of open questionnaires and focus group interviews for college students majoring in beauty. Participants in the study majored in beauty at 2-year and 4-year universities nationwide. The enrolled students were set as a population, and 250 people were adopted as a random sampling method and used for the survey. The series of results are as follows. First, as a result of inductive content analysis of open questionnaires, the educational service quality of beauty majors was derived into five areas: major knowledge, educational quality, professor-student intimacy, student needs reflection, usability, curriculum composition, environmental efficiency, educational equipment, and reputation. Second, as a result of the focus group interview, inductive content analysis was more reasonably pointed out and derived in depth. As a result of this study, it is believed that it can be used as basic data for the development of measurement tools for educational service quality of beauty majors.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.809-816
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• 2006

More than effectively judging the existence of reinforcing bars under multi boundary layers and void shapes in concrete, this study aims to develop the analysis algorithm of radar response on multi boundary layers in reinforced concrete and radar capable of estimation of the shape of specific voids in plain concrete. To detect or estimate reinforcing bars and void shapes in these conditions, the simulation analysis model of transmission and reflection wave of electromagnetic radar is used. This radar simulation model is carried out with reinforced or non reinforced concrete of various boundary conditions and void shapes. And, the output signals (images) of radar simulation results are calculated and represented by convolution method. As the results, it is clarified that this simulation analysis technique can be used to analyze radar response on multi boundary layers in reinforced concrete and void shapes in concrete.

• (The) Research of the performance art and culture
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• no.39
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• pp.167-196
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• 2019

Geugyesuryeonguhoe founded the Silheommudae and chose Nikolai Vasilevich Gogol's Revizor as the founding performance. This Revizor theater performance was a performance equivalent to the founding performance of the Geugyesuryeonguhoe, so it had to be based on the discussion and consensus of the members. Nevertheless, the reasons for selecting this work, the actual performance situation, and whether or not it was successful were not properly addressed in the research data so far. As a result, Revizor performance of Silheommudae did not escape the powerful influence of Revizor theater performance performed at Tsukiji(築地) theater in Japan. In addition, the original design of stage, acting and acting concept of Silheommudae was not confirmed. After this performance, the change of the performance method of Geugyesuryeonguhoe was inevitable. And Geugyesuryeonguhoe was forced to carry out its own reflection on the problems in the stage process.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.721-728
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• 2023

This study was conducted with the aim of exploring the essence of the achievements experienced by nursing students while enhancing their problem-solving abilities through simulation practical training. The study participants included 13 fourth-year nursing students, and data were collected through individual interviews conducted after the simulation practical training. Data analysis followed the qualitative research method of content analysis, involving coding, categorization, and thematization of the data. The results of this study revealed that nursing students' achievement experiences through simulation practical training included the following processes: "confirming confidence through improvement," "acknowledging change," "experiencing nursing self-efficacy," and "getting closer to the goal of clinical practice." Furthermore, it is suggested that efforts should be made to implement efficient operation and evaluation tools through multifaceted and meticulous design to promote integrated learning through simulation practical training and to confirm the process of internalizing knowledge through reflection by nursing students.

• Journal of Ocean Engineering and Technology
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• v.37 no.6
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• pp.247-255
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• 2023

Interference and collisions often occur in the loading process at shipyards. Existing simulation methods focus primarily on resource processes and schedules, and there is a lack of real-time reflection in the complex and highly variable loading process. This study aims to develop a spatial environment incorporating real-time product data, such as hulls, and confirms its effectiveness by simulating various construction scenarios. As a method, a near real-time spatial environment based on broadband laser scanning was established, with the situation of loading heavy cargo assumed when converting an existing ship into an LNG dual-fuel propulsion ship. A case study simulation of near-real-time cargo loading processes was then conducted using Unity 3D to confirm the interference and collision risks within the spatial environment. The results indicated that interference occurred in structures previously not identified in the design data, and a collision occurred during the loading object erection phase. The simulation confirmed that the identification of interference and collision risks during the erection phase highlights the need for a relocation or removal process of potential hazards before erection takes place. An improved erection simulation that integrates near real-time data could effectively prevent interference and collision risks.

• The Journal of the Acoustical Society of Korea
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• v.25 no.5
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• pp.229-238
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• 2006

This paper shows the analytic error caused by the inconsistency of the approximation order between the non local boundary condition (NLBC) and the parabolic governing equation. To obtain the analytic error, we first transform the NLBC to the half space domain using plane wave analysis. Then, the analytic error is derived on the boundary between the true numerical domain and the half space domain equivalent to the NLBC. The derived analytic error is physically expressed as the artificial reflection. We examine the characteristic of the analytic error for the grazing angle, the approximation order of the PE or the NLBC. Our main contribution is to present the analytic method of error estimation and the application limit for the high order parabolic equation and the NLBC.

• Journal of Digital Convergence
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• v.21 no.3
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• pp.15-22
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• 2023

This study is a case study designed to create and implement a project-based introduction to nursing science, with the aim of analyzing students' experiences and perceptions following its implementation. The study targeted a total of 95 nursing students at G University in S City who enrolled in the introduction to nursing science course in 2021 and 2022. Data collection took place from September 2021 to December 2022, and data analysis involved examining reflective journals submitted by students after completing the project activities, using content analysis. The research results revealed four categories and nine themes. The four categories were 'Making Challenging Studies More Accessible,' 'Engaging and Enjoyable Learning Experiences,' 'Enhanced Teamwork,' and 'Presentation Limitations.' The project-based learning method was found to be effective and applicable in nursing education, demonstrating positive effects on students' attitudes and learning outcomes. However, since the study focused on students from a single university, it is suggested that future research include repeated studies and extend the application to other nursing courses to validate its effects.

• The Research Journal of the Costume Culture
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• v.32 no.3
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• pp.334-344
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• 2024

This study aimed to develop a new convergence course applying project-based learning (PBL) and collaborative teaching methods and identify its educational effects. The course development proceeded as follows: First, three instructors collaborated to define course goals, plan objectives, content, and methods, and create a syllabus for a PBL-based fashion studio course. Roles were divided to maximize expertise: one instructor focused on fashion design, another on three-dimensional cutting, and the third on flat cutting, and digital techniques. Second, the classes were conducted and feedback on student progress was shared, enhancing class quality and engagement. Third, teaching effectiveness was assessed through learner evaluation questionnaires, reflection journals, and performance assessments. Lastly, based on the results from these evaluations, positive aspects of the course were reviewed, and ways to modify it and enhance course quality for continuous improvement were explored. The results showed high satisfaction with the learning effects on major competencies, indicating that students not only effectively learned major skills but also improved their communication and teamwork. The students perceived the teaching methods positively allowing them to be more active in class. Instructors noted that the course produced higher-quality design and production outcomes compared to previous courses. Overall, the course applying PBL and collaborative teaching methods was found to improve educational quality and effectiveness, making it a valuable approach for learner-centered education.