• Journal of Digital Convergence
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• 제21권3호
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• pp.23-31
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• 2023

As COVID-19 is nearing the end, the travel industry is gradually picking up steam as the attention of those who have not traveled in nearly a few years is drawn back to travel. Accordingly, we intend to develop a travel-related application to help with travel. According to the current trend of SNS, this application provides a review function as the main function. In addition, travel records can be stored through the gallery, and the route to the destination can be conveniently viewed through navigation. People usually use multiple applications at the same time depending on their purpose when traveling. This project aims to improve convenience by developing applications that combine various functions to eliminate such hassle. The development tool uses Android Studio.

• Journal of the Korea Institute of Building Construction
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• 제24권3호
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• pp.285-295
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• 2024

This study investigated the impact of accelerated carbonation on Ordinary Portland Cement(OPC) paste that had undergone steam curing at 500℃·hr. Two carbonation environments were examined: atmospheric carbonation(1atm, 20% CO₂) and pressurized carbonation(5atm, 99% CO₂). Chemical analysis using X-ray diffraction(XRD) and Fourier-Transform Infrared spectroscopy(FT-IR) were conducted, along with physical characterization via scanning electron microscopy(SEM) and compressive strength testing. Results indicated that atmospheric carbonation with 20% CO₂ concentration significantly densified the internal microstructure of the OPC paste, leading to enhanced compressive strength. Conversely, pressurized carbonation at 5atm with 99% CO₂ concentration resulted in rapid densification of the surface structure, which hindered CO₂ diffusion into the sample. This limited the extent of carbonation and prevented the improvement of physical properties.

• Journal of Ceramic Processing Research
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• 제21권1호
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• pp.57-63
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• 2020

Chemical looping hydrogen production (CLHP) is an attractive technology for H₂ production due to its ability to produce H₂ and capture CO₂ from fossil fuels simultaneously. In this paper, we present MgFe₂O₄ as an oxygen carrier material with high efficiency, low cost, and stable properties for CLHP. The redox reactions occurred reversibly in the fuel, steam, and air reactor as MgFe₂O₄→MgO/Fe, MgO/Fe→MgO/Fe₃O₄, and MgO/Fe₃O₄→MgFe₂O₄, respectively. The oxygen transfer capacities of MgFe₂O₄ for 5% H₂/N₂ and 5% CO/N₂ gases were about 23 wt% at 900 ℃. Both the oxygen transfer capacity and rate were well maintained during 10 redox cycles at 900 ℃. No phase changes or agglomeration occurred as the redox cycle number increased. Similarly, MgFe₂O₄ did not exhibit significant degradation in its total amount or maximum rate of H₂ production during four redox cycles. The average calculated amount of H₂ production for MgFe₂O₄ was 2,806 L/day per unit mass (kg).

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2534-2544
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• 2024

This paper proposes a flooding safety system (FSS) and its operation strategy that can provide long-term safety and effective maintenance for modules of small modular reactor (SMR) and metal containment maintained at dried environment during normal operation. During hypothesized accidents, the FSS re-collects the evaporated steam into the common pool by the condenser installed above the common water pool and provides an emergency coolant for the cavities and auxiliary pools. This study suggested that the condensate re-collection strategy using the FSS can effectively delay the depletion of available water in response to the accidents. Without recollection, the achievable grace periods ranged from 44 to 1507 days for six-module and one-module accidents, respectively. However, with a full re-collection (ratio = 1.0), the time to total depletion of emergency coolant was estimated indefinite. Even with a partial re-collection ratio of 0.3, a grace period of 83.5 days could be ensured for a six-module transient. This study reported the effectiveness of condensate re-collection and the FSS as an innovative safety management strategy and system. Employing a condensate re-collection strategy with a high re-collection ratio can enhance the long-term safety and effective convenience of SMR operations and maintenance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제24권5호
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• pp.195-202
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• 2024

Since the permanent shutdown of the Kori No. 1 reactor, research on nuclear power plant decommissioning has been actively conducted. The core facilities (reactor pressure vessel, steam generator, reactor coolant pump, and pressurizer) of a nuclear power plant have the highest radioactivity among the structures of a nuclear power plant, and the reactor pressure vessel (RPV) is the most radioactive object other than the nuclear fuel. In order to dismantle them, accurate preliminary information (2D, 3D models, etc.) and radiological characterization of the dismantling object are required, as well as feasibility studies of dismantling equipment and dismantling processes. However, it is impossible to review the dismantling process with only prior information and radiological characterization, and when using physical mock-ups, simulation and training in a virtual environment are necessary due to the difficulty of applying various dismantling equipment. In this paper, we developed a remote decommissioning training system that can improve the remote decommissioning technology of the nuclear power plant decommissioning process and the decommissioning skills of decommissioning workers by applying virtual reality and haptic technology.

• The Journal of Internal Korean Medicine
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• 제45권4호
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• pp.792-809
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• 2024

Objectives: The purpose of this case study was to report the therapeutic effect of Korean medicine treatment for chronic obstructive pulmonary disease (COPD) patient with dyspepsia and anorexia after surgery for colon cancer and chemotherapy. Methods: A patient with COPD was hospitalized to treat dyspnea, dyspepsia, and anorexia that occurred after surgery for colon cancer and chemotherapy during 22 days. The patient was treated with herbal medicine (Yangjin-tang), acupuncture, pharmaco-puncture, herbal steam therapy, moxibustion, and pulmonary rehabilitation. The effectiveness of the treatment was assessed with modified Medical Research Council (mMRC) scale, Numeric Rating Scale (NRS) for dyspnea and dyspepsia, walking distance, weight, peak expiratory flow (PEF), radiography, pulmonary function test, and laboratory test. Results: The Korean medicine treatment improved mMRC from Grade 4 to Grade 3, NRS of both dyspnea and dyspepsia, walking distance, and maxillary sinusitis on paranasal sinus X-ray. However, there were no changes in weight, PEF, and chest X-ray. Conclusion: The Korean medicine treatment was effective in improving the symptoms of the COPD patient, including dyspnea, dyspepsia, and anorexia. This study suggests that Korean medicine treatment can have therapeutic effect on comorbidities such as dyspepsia and anorexia.

• The Journal of Korean Medicine
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• 제45권2호
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• pp.41-54
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• 2024

Objectives: Cannabis root is a medicinal plant that has been used in traditional medicine around the world. However, in previous studies using simple extracts, the biological activity was not relatively prominent compared to other herbal medicines. The aim of the present study is to confirm the enhancement of anti-inflammatory activity and bioactive compound of Cannabis root extract prepared by combined processing process. Methods: A series of processes including repeated steam and dry, fermentation, hydrothermal extraction and ethanol extraction was applied to Cannabis root. The antioxidant content of cannabis root extracts obtained through a combined processing process was investigated by analyzing the total phenolic, tannin, and flavonoid contents. Anti-inflammatory effects were tested in LPS-treated RAW264.7 cells. The anti-inflammatory mechanism was examined by western blot. Finally, the component profile of Cannabis root extract was analyzed using High Performance Liquid Chromatography (HPLC) and Thin layer chromatography (TLC). Results: The cannabis root extract prepared by complex processing process had higher antioxidant and anti-inflammatory effects than simple extract. Total phenolic and tannin contents were significantly increased, and DPPH free radical inhibition activity was strengthened by combined processing process. Increased NO production and iNOS expression in LPS-treated RAW264.7 cells were decreased in a concentration-dependent manner upon extract treatment by complex processing process. Additionally, the Stigmasterol content of Cannabis root extract was increased through a complex processing process. Conclusions: Further research is needed on the mechanisms and substances that exhibit the anti-inflammatory effects of Cannabis roots extract prepared by complex processing process.

• Economic and Environmental Geology
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• 제46권4호
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• pp.313-327
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• 2013

In the study, three-dimensional geostatistical simulations on McMurray Formation which is the largest oil sand reservoir in Athabasca area, Canada were performed, and the optimal site for steam assisted gravity drainage (SAGD) was selected based on the predictions. In the selection, the factors related to the vertical extendibility of steam chamber were considered as the criteria for an optimal site. For the predictions, 110 borehole data acquired from the study area were analyzed in the Markovian transition probability (TP) framework and three-dimensional distributions of the composing media were predicted stochastically through an existing TP based geostatistical model. The potential of a specific medium at a position within the prediction domain was estimated from the ensemble probability based on the multiple realizations. From the ensemble map, the cumulative thickness of the permeable media (i.e. Breccia and Sand) was analyzed and the locations with the highest potential for SAGD applications were delineated. As a supportive criterion for an optimal SAGD site, mean vertical extension of a unit permeable media was also delineated through transition rate based computations. The mean vertical extension of a permeable media show rough agreement with the cumulative thickness in their general distribution. However, the distributions show distinctive disagreement at a few locations where the cumulative thickness was higher due to highly alternating juxtaposition of the permeable and the less permeable media. This observation implies that the cumulative thickness alone may not be a sufficient criterion for an optimal SAGD site and the mean vertical extension of the permeable media needs to be jointly considered for the sound selections.

• Journal of Nutrition and Health
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• 제36권1호
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• pp.9-17
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• 2003

The preparation method of a soluble dietary fiber from oak wood (Quercus mongolica) and the effect of the soluble dietary fiber on physiological function in rat fed high cholesterol diets was investigated. The best condition for steam explosion method was 25 kgf/㎤ pressure for 6 min. The exploded samples were delignified by the filtration treatment with 1% NaOH for several times, which is the best condition. The enzymatic hydrolysis of Cellusoft cellulase was more effective than Onozuka R-10 cellulase. The manufactured soluble dietary fiber was assayed using gel permeation chromatography (GPC) and it was dissolved in water. Average molecular weight distribution of manufactured soluble dietary fiber was about 348-1,200 and it was assumed the oligomer form fraction. In order to compare the manufactured soluble dietary fiber with commercial soluble dietary fiber (pectin) on the physiological function, Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal diet and five high cholesterol diet containing 1% cholesterol. The high cholesterol diet groups were classified to fiber free diet (FF group), 5% pectin (5P group), 10% pectin (l0P group), 5% manufactured soluble dietary fiber (5M group) and 10% manufactured soluble dietary fiber (10M group). Body weight gains in all soluble dietary fiber groups were lower than FF group. Food intakes were increased in all soluble dietary fiber groups than that of FF group. Food efficiency ratio (FER) was significantly decreased in all soluble dietary fiber groups than that of the FF group, and it was especially was highest in 10% supplemented soluble dietary fiber group. The weight of liver of the soluble dietary fiber supplemented groups were lower than those of the FF group, but weights of cecum and small intestine of all supplemented soluble dietary fiber groups were significantly increased, compared with that of FF group. The weights and water contents in feces were significantly increased by the soluble dietary fiber. The activity of the glutamic oxaloacetic transaminase in soluble dietary fiber groups were significantly decreased than those of FF group. The hepatic glutathione S-transferase activity in all soluble dietary fiber supplemented groups were higher than that of FF group. The physiological effects of the manufactured soluble dietary fiber are the same as the commercial soluble dietary fiber (pectin). The preparation method of the soluble dietary fiber from the oak chips suited to its purpose. (Korean J Nutrition 36(1) : 9~17, 2003)

• Journal of The Korean Association For Science Education
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• 제32권1호
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• pp.30-45
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• 2012

Educational communities around the world have concentrated on integrative efforts among science, technology, engineering and mathematics (Science, Technology, Engineering, and Mathematics: STEM) subjects. Korea has focused on integrative education among STEAM (Science, Technology, Engineering, Arts, and Mathematics) school subjects to raise talented human resources in the fields of science and technology. The purpose of this study was to analyze secondary school science, technology, and mathematics teacher's perceptions and needs toward integrated education and integrative STEM education. A total of 251 secondary school teachers from all areas of the country who have taught science, mathematics, and technology were surveyed by using a self-reported instrument. The findings were as follows: First, teachers have used little integrated education in their classes due to insufficient time in the actual preparation of the integrated education and the lack of expertise, teaching experience, and teaching-learning materials for the integrated education, while they have positive thoughts about the need of integrated education. Second, they presented several needs to facilitate the integrated education: development of a variety of integrated programs, school administrative and financial support, and in-service teachers' training. Third, overall perception toward integrated STEM education was not sufficient, but most teachers perceived the need toward integrated STEM education due to students' development in their creativity, thinking skills, and adaptability. Fourth, they perceived that it was imperative to develop the various integrated STEM education programs, distribute the materials, and help STEM teachers' understanding toward integrated STEM education. Fifth, they perceived that the most relevant method to integrate STEM subjects was the problem solving approach. In addition, they appreciate that the integrated STEM education is highly efficient in not only developing integrated problem solving skills and STEM related literacy, but also in positively impacting the rise of talented human resources in the fields of science and technology. In order to increase the awareness of STEM-related secondary school teachers and vitalize the integrated STEM education, it is necessary to develop and spread a variety of programs, effective teaching and learning materials, and teachers' training programs.