• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.138.2-138.2
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• 2013

Copper oxide is a multi-functional material being used in various research areas including catalysis, electrochemical materials, oxidizing agents etc. Among these areas, we have synthesized and utilized graphene based copper oxide nanocomposites (CuOx/Graphene) for the catalytic applications (C-N cross coupling reaction). Briefly, Cu precursors were anchored on the graphite oxide(GO) sheets being exfoliated and oxidized from graphite powder. Two different crystalline structures of Cu2O and CuO on graphene and GO were prepared by annealing them in Ar and O2 environments, respectively. The morphological and electronic structures were systemically investigated using FT-IR, XRD, XPS, XAFS, and TEM. Here, we demonstrate that the catalytic performance was found to depend on oxidative states and morphological structures of CuOx graphene nanocomposites. The relationship between the structure of copper oxides and catalytic efficiency toward C-N cross coupling reaction will be discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.127-128
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• 2022

The construction industry has a higher disaster rate than other industries, so safety education and management are highly important. In order to reduce the construction accident rate, it is necessary to study the key safety management factors reflecting the characteristics of the construction industry, where there are differences in processes and manpower input for each process, and a small number of managers. Therefore, in this study, key safety management factors for each Process of construction were derived through cross-analysis between safety accident types and accident occurrence objects through disaster case data. The extracted key safety management factors are expected to provide useful information for safety education and supervision of construction sites.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.40-44
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• 2023

The defect detection based on deep learning requires minimal loss and high accuracy to pinpoint product defects. In this paper, we confirm the loss rate of deep learning training based on disc-shaped artificial scaffold images. It is intended to compare the performance of Cross-Entropy functions used in object detection algorithms. The model was constructed using normal, defective artificial scaffold images and category cross entropy and sparse category cross entropy. The data was repeatedly learned five times using each loss function. The average loss rate, average accuracy, final loss rate, and final accuracy according to the loss function were confirmed.

• Journal of Korean Association for Spatial Structures
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• v.12 no.4
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• pp.47-56
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• 2012

This paper describes the structural design and optimization of sinusoidally corrugated web girder by using EUROCODE (EN 1993-1-5). The optimum design methodology and characteristics of the optimal cross-section are discussed. We investigate a shear buckling and the concerned standards for corrugated web and explain the equations to obtain a critical stress according to buckling type. In order to perform optimization, we consider an objective function as minimum weight of the girder and use the constraint functions as slenderness ratio and stresses of flanges as well as corrugated web and deflection. Genetic Algorithm is adopted to search a global optimum solution for this mathematical model. For numerical example, the clamped girder under the concentrated load is considered, while the optimum cross-sectional area and design variables are analyzed. From the results of the adopted example, the optimum design program of the sinusoidally corrugated web girder is able to find the suitable solution which satisfied a condition subject to constraint functions. The optimum design shows the tendency to decrease the cross-sectional area with the yielding strength increase and increase the areas with load increase. Moreover, the corrugated web thickness shows a stable increase concerning the load.

• Journal of Korean Elementary Science Education
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• v.19 no.2
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• pp.57-74
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• 2000

Students' concepts of scientific phenomena have become a point of focus in science education research. This study investigated into developmental process and mechanism of the students' respiration concept through a cross-age study. This study utilized the 1st, 3rd, 6th grade elementary students to find out changes in student's understanding of the concept of respiration. The 1st and 3rd grade level students were interviewed what the respiration mean and whether each of living things respires, etc. The 6th grade students were interviewed and tested. Respiration is a word that students come across often in everyday life. It was found that they were more likely to associate respiration with its more common concept of breathing or gas exchange as opposed to its more scientific definition as the process in which nutrients are oxidized to provide energy. This trend didn't improve as they advanced grade. This is an indication that the knowledge system of student is split into a generic knowledge system and scientific knowledge system. Understanding of concept increased and differentiated across grade levels but that understanding was limited. They overcome their tendency to base their understanding of respiration on their understanding of human phenomena and learn to integrate their understanding of biological phenomena through a one organ - one role type of logic. They also intuitively explain everything based on their own experience.

• Current Optics and Photonics
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• v.4 no.4
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• pp.317-325
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• 2020

Accurate estimation of spatial frequencies and phases for illumination patterns are essential to reconstructing super-resolution images in structured illumination microscopy (SIM). In this manuscript, we propose the improved component cross-correlation (ICC) algorithm, which is based on optimization of the cross-correlation values of the overlapping information between various spectral components. Compared to other algorithms for spatial-frequency and phase determination, the results calculated by the ICC algorithm are more accurate when the modulation depths of the illumination patterns are low. Moreover, the ICC algorithm is able to calculate the spatial frequencies and phases simultaneously. Simulation results indicate that even if the modulation depth is lower than 0.1, the ICC algorithm still estimates the parameters precisely; the images reconstructed by the ICC algorithm are much clearer than those reconstructed by other algorithms. In experiments, our home-built SIM system was used to image bovine pulmonary artery endothelial (BPAE) cells. Drawing support from the ICC algorithm, super-resolution images were reconstructed without artifacts.

• The Pure and Applied Mathematics
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• v.22 no.1
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• pp.75-90
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• 2015

In this paper the existence of global solutions of the parabolic cross-diffusion systems with cooperative reactions is obtained under certain conditions. The uniform boundedness of $W_{1,2}$ norms of the local maximal solution is obtained by using interpolation inequalities and comparison results on differential inequalities.

• Journal of the Chungcheong Mathematical Society
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• v.32 no.1
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• pp.149-156
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• 2019

This paper present the global generalized cross validation as the appropriate choice of the regularization parameter in the preconditioned Gl-LSQR method in solving image deblurring problems. The regularization parameter, chosen from the global generalized cross validation, with preconditioned Gl-LSQR method can give better reconstructions of the true image than other parameters considered in this study.

• Child Health Nursing Research
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• v.23 no.4
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• pp.515-524
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• 2017

Purpose: The study was undertaken to see whether the culturally sensitive education for perinatal care using a face to face approach improves understanding of spouse's culture, knowledge of pregnancy and parenting skills, and self-efficacy among Korean husbands and Vietnamese wives. Methods: This study has a pre- and post-test study design conducted in a total of 13 couples who live in Seoul and agreed to participate. The education program consisted of lecture and hands on practice. The self-administered questionnaires and the checklist developed based on the educational purpose were used to assess the education effects. Results: The knowledge scores on Korean/Vietnamese culture, pregnancy and parenting skills as well as the performance scores on hand washing, pelvic strengthening, feedings and newborn bathing techniques were significantly improved in both husbands and wives after education, but pelvic floor exercises were improved only in wives. Conclusion: Overall, the individual education for culturally sensitive perinatal care was effective in our study participants.

• Cross-Cultural Studies
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• v.36
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• pp.149-173
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• 2014

This paper examines language policies of Ghana and Tanzania (former British Colonies) since independence. The view that language use in education is a problem for African countries is evident in the ever changing language in education policies in many African countries. Because of the inevitable multilingual situation in many African countries, there are unavoidable challenges in their quest to adopt a language policy that works for the entire country since it is not practical to adopt all the languages spoken in the country as Media of Instruction. Ghana is not immune to this challenge and has fallen victim to this tendency to change the language in education policy from time to time in an attempt to adopt a satisfactory policy which would yield the intended results. Tanzania, however, is one of the few African countries that have found a sustainable language in education policy since independence. Nonetheless, it has its fair share of challenges as a consequence of the perceived competition between Kiswahili and English as official languages. The paper discusses the challenges that both Ghana and Tanzania face against the background of colonization. The paper also offers a discussion on possible future perspectives for the two countries.