• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.307-312
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• 2023

In this study, a catalytic oxidation-heat recovery system was designed that can remove unreacted with a concentration of about 1% to 6% in the exhaust gas of hydrogen fuel cells and recover heat to ensure safety in the hydrogen economy. The safety system was devised by filling hydrogen oxidation catalysts at room temperature that can remove unreacted hydrogen without any energy source, and an exhaust-heat recovery device was integrated to efficiently recover the heat released from the oxidation reaction. Through CFD analysis, variations in pressure and fluid within the system were shown depending on the filling conditions of the hydrogen oxidation system. In addition, it was found that waste heat could be recovered by optimizing the temperature of the exhaust gas, flow rate, and pressure conditions within the heat recovery system and securing hot water above 40 ℃ by utilizing the exhaust gas oxidation heat source above 300 ℃. Through this study, it was possible to confirm the potential of utilizing hydrogen processes, which are applied in small to medium-sized systems such as hydrogen fuel cells, as a safety system by evaluating them at a pilot scale. Additionally, it could be a safety guideline for responding to unexpected hydrogen safety accidents through further pilot-scale studies.

• Journal of Korea Water Resources Association
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• v.55 no.4
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• pp.279-289
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• 2022

Since the frequency of heavy rainfall is increasing due to climate change, water levels in the river exceed past historical records. The rating-curve is to convert water level into flow dicscharge from the regression analysis of the water level and corresponding flow discharges. However, the rating-curve involves many uncertainties because of the limited data especially when observed water level exceed past historical water levels. In order to compensate for insufficient data and increase the accuracy of flow discharge data, this study estimates the flow discharge in the river computed mathematically using Monte Carlo simulation based on a 1D hydrodynamic numerical model. Based on the existing rating curve, a random combination of coefficients constituting the rating-curve creates a number of virtual rating curve. From the computed results of the hydrodynamic model, it is possible to estimate flow discharge which reproduces best fit to the observed water level. Based on the statistical evaluation of these samples, a method for mathematically estimating the water level and flow discharge of all cross sections is porposed. The proposed methodology is applied to the junction of Yochoen Stream in the Seomjin River. As a result, it is confirmed that the water level reproducibility was greatly improved. Also, the water level and flow discharge can be calculated mathematically when the proposed method is applied.

• Journal of Science Education
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• v.47 no.1
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• pp.52-62
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• 2023

This study examines how prospective earth science teachers perceive the concept of "equilibrium" and "interaction between Earth's spheres" in understanding Earth's radiative equilibrium and tries to identify their misconceptions. For this purpose, a questionnaire was designed and put to them to look into their thought flow based on the items that appeared in the national level evaluation. As a result of analyzing their answers, even though all the prospective teachers correctly described the concept of radiative equilibrium, about 90% of them did not apply the concept of radiative equilibrium to the new environment of the Earth without atmosphere. They do not seem to be able to smoothly derive the concept of a new 'interaction' between the changed regions and a new 'equilibrium' that will be reached over a long period of time. In this respect, it is likely that the textbooks had some influence on the formation of their concepts. In particular, high school Earth Science textbooks describe the Earth's radiation equilibrium in a quantitative manner, focusing on the heat budget of the equilibrium state rather than the process of reaching radiation equilibrium. Such an approach of textbooks might be an obstacle to fostering students into creative convergence-type talents pursued in the 2015 revised curriculum. Meanwhile, in order to eliminate the misconceptions of students often found in the understanding of Earth's radiation equilibrium, this study suggests that the core concepts need to be dealt with more attention even in college courses for training prospective teachers.

• Journal of Popular Narrative
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• v.25 no.2
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• pp.169-216
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• 2019

This study proposes the concept of Bachchin's Chronotope as a tool for analyzing coevolution between the genre of the epic and society. Bachchin says through the concept of chronotope, literary works are on the foundation on which the axs of time and space intersect, and the literary works standsuch intersections are always conversing with social and historical chronotopes and mutually penetrating. Thus, finding and analyzing chronotope in literary works and extended things such as films and dramas reveals how chronotope and chronotope of a society have created specific social realities through a process of resonance. To make analytical use of this concept, we proposed a "cronotope drama analysis method" and concretely analyzed the genre of Korean medical dramas. The naturalized categories of health care, health, and disease are socially constructed entities, and the analysis of public works that has a significant impact on this process of social construction is essential but was underperformed. According to the analysis, the Korean medical drama's "Chronotope" has evolved using "Chronotope of the school" and "Chronotope of the secret chamber". At this time, the genre of Chronotope was expanding spatially and converging in time. In other words, the influence of structures and systems within the genre has grown, and the capacity of individual actors has decreased. This change in chronotope was interpreted as resonating with the social reality of neo-liberalistic spatial expansion and simultaneous production. The neo-liberalistic trend that dominates Korean society has embraced the category of health care and was further influencing the chronotope of drama text. It can also be inferred that the popular understanding of health care produced by the medical drama genre has taken a break in the process of forming a social reality of health care again.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.4
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• pp.603-613
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• 2017

The purpose of this study was to develop an scientific inquiry learning module by applying ESD and to verify its effect so that students could understand sustainable development and geology concepts by reconstructing the contents of the geology related unit. For this purpose, the "Volcanoes and Earthquakes" unit in the 3-4 grade group of the Korea national curriculum was selected and the scientific inquiry learning module was developed. The developed inquiry learning module consisted of one textbook and one teacher 's guidebook, and it was put into one class of elementary school to verify the effect. As a result, the teacher said that it was good to be taught contents of ESD and it was useful because of the concreteness of inquiry activities. The students responded that they were interesting because developed textbook is more often the interesting picture and activity than traditional textbook. And the students responded that 'ESD' has been an opportunity to be interested in science.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.1
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• pp.1-16
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• 2018

A residential space where a person lives in may change following the flow of time and it has evolved in various shapes through the development process of a city. In particular, after the 1900s when the modern urban planning was first applied in full-scale, the urban environment and residential environment have formed cities through systematic planning. Under the assumption that the level of satisfactory life for urban residents residing in such an urban environment would be influenced mutually with the residential environment and urban environment to carry out this study, and as for the methodology of this study, the questionnaire was implemented with the subject of residents in Seoul City and analysis was implemented for regression analysis through SPSS 20.0 program. The results of the study are shown as follows. First, the relationship of the residential environment and urban environment is classified for convenience, safety and pleasance to have the important implication, and the level of satisfaction for the residential environment is analyzed to show implications with influence on the level of satisfaction for settlement consciousness. Second, the relationship of influence of residential environment on the settlement consciousness with the characteristics of urban environment is statistically noticeable and the stability and pleasance would have the statistically noticeable influence on satisfactory residential environment and the convenience would not render noticeable influence. And, third, under the characteristics of urban environment, convenience does not have direct influence on the settlement consciousness and it is confirmed to influence on the settlement consciousness indirectly only through the satisfaction of variation in the residential environment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.575-589
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• 2008

In the present work, we investigate the hydrodynamic behavior of a turbulent bore, such as tsunami bore and tidal bore, generated by the removal of a gate with water impounded on one side. The bore generation system is similar to that used in a general dam-break problem. In order to the numerical simulation of the formation and propagation of a bore, we consider the incompressible flows of two immiscible fluids, liquid and gas, governed by the Navier-Stokes equations. The interface tracking between two fluids is achieved by the volume-of-fluid (VOF) technique and the M-type cubic interpolated propagation (MCIP) scheme is used to solve the Navier-Stokes equations. The MCIP method is a low diffusive and stable scheme and is generally extended the original one-dimensional CIP to higher dimensions, using a fractional step technique. Further, large eddy simulation (LES) closure scheme, a cost-effective approach to turbulence simulation, is used to predict the evolution of quantities associated with turbulence. In order to verify the applicability of the developed numerical model to the bore simulation, laboratory experiments are performed in a wave tank. Comparisons are made between the numerical results by the present model and the experimental data and good agreement is achieved.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.359-370
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• 2023

The purpose of this study is to analyze the meaning of picture book reading experience for 2-year-old children using sensory reading media and to suggest a plan to support language ability through meaningful reading. For this study, 35-month-old boys were selected, and data collection was conducted based on participant observation and field record notes at home and analyzed qualitatively. In this study, for about two months from March 20th to April 30th, 2021, all the time of exploring picture books and playing were recorded and the data were collected. The recording time was about 20 hours, and the collected data and field records were transcribed on 108 pages of A4 paper. The results of the study showed that 2-year-old infants were immersed in exploring new media through the experience of reading picture books using sensory reading media, comparing with similar media, and reading picture books using media. In addition, it was found that the emergence of leading reading that selects and reads books by Hans himself, exploration using reading media, and play linked to picture books in everyday life.This can be seen as a result of suggesting that the picture book reading experience of 2-year-olds using sensory reading media is meaningful to the reading experience of infants.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.389-397
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• 2023

This study examines how macro-economic conditions, fashion momentum, and inter-genre competition affect movie genre's popularity, thus shaping fashion trends in the feature film market in Korea. Using panel data analysis of genre-specific audience sizes with 6 genre cateories and 132 monthly time points, we found that favorable economic conditions generate the fashion trend in the action/crime genre, while the deterioration of the economic conditions leads to the decline of action/crime genre. The finding implies that economic situations influence cultural consumers' psychological states, which in turn shape the fashion trend in certain direction. Furthermore, we found that the action/crime genre has a greater fashion momentum and its competitive power is stronger than other genres, suggesting that this genre has longer fashion cycle even if other genres rise to the top in their popularity. We argue that such enlengthened fahion cycle and competitive stength of the action/crime genre are associated with its breadth of niche width and audience loyalty. Scholarly and practical implications are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.245-253
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• 2009

Road facility is the most fundamental infrastructure for traffic and various information for smooth traffic is included in road surfaces. Various information included in road surfaces should be often removed and reinstalled by partial damage and aging. In addition, the existing road surface information should be removed in order to mark new information as traffic information changes. The existing road surface removal method suing grinders and torches had problems such as dangerous working equipment and workers' direct exposure to cars. In addition, although water-jet system using super high-pressure water was used to remove road surface in order of improvement of traditional method, there are another problems such as limitations according to water-tanks and water frost on the road surfaces after work. Therefore, this study analyzes and suggests systems to develop prototype after analyzing dry ice blaster in order to improve the current road surface removal methods. In addition, the study analyzes the possibility of introduction of dry ice blaster through a test for proposing an automatized equipment for new road surface mark removal considering environment and work efficiency, and compare traditional method with introduced dry ice blaster for operating cost.