• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.123-129
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• 2022

Recently, the penetration rate of Magnetic Resonance Imaging (MRI) is higher than the average among OECD member countries, and the number of MRI scans is increasing. However, MRI scans take longer than other medical devices, and patient movement must be minimized. Therefore, patient discomfort always follows. When the examination is performed in the discomfort of the patient, it is difficult to perform an accurate examination, and it is difficult to obtain an image of diagnostic value. So, in the past, the patient was asked to read the written guide for the risk and cooperation of MRI, but it was composed of technical terms and difficult-to-understand sentences, so it was difficult to understand. The purpose of this study is to supplement these problems and increase the understanding of MRI scans to help acquire images of diagnostic value. In addition, it is intended to evaluate the excellence of leaflet education by evaluating the understanding and satisfaction of patients. As shown in the results of this study, understanding and satisfaction scores were higher after education than before leaflet education, and it was found that there was a difference in understanding according to academic background. However, there was no difference in the number of MRI scans. That is, there was no difference in the number of inspections due to leaflet education. In the future, leaflet education will be widely used for MRI examination, and it is necessary to study the qualitative evaluation of images after leaflet education in the future.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.77-85
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• 2022

Retinaldehyde (RA), vitamin A derivative, is an intermediate between retinol and retinoic acid and has an excellent wrinkle improving effect. In this study, Drug-in-cyclodextrin-in-liposome (DCL) was used to enhance the stability and skin penetration of RA. The complex of RA and hydroxypropyl-beta-cyclodextrin (HP-β-CD) was prepared by the freeze-drying method, and the presence or absence of inclusion of retinal was confirmed by UV-Vis spectrometer, FT-IR and SEM images. RA was captured in HP-β-CD about 95.6% on 1 : 15 (w/w). The retinal-HP-β-CD complex was encapsulated in liposomes using a homomixer and microfluidizer, with an average particle size of 215 ± 4.2 nm and a zeta potential of -31.2 ± 0.5 mv. In the evaluation of the degradation stability of RA, degradation rate of RA-HP-β-CD-liposomes in water was 1.8% higher than RA-liposome (5.8%), RA-HP-β-CD complex (9.7%) and RA alone (37.6%). RA cream (0.05% RA) including RA-HP-β-CD-liposomes was prepared for clinical test with wrinkle-improving efficacy and skin dermis denseness evaluated for 2 or 4 weeks. RA cream showed a significant wrinkle improving effect without skin irritation. In conclusion, it was confirmed that the double stabilization technology using the DCL system contribu tes to the effect of improving skin wrinkles by increasing the stabilization of retinal.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.356-362
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• 2022

Research related to hydrogen technology is being actively conducted around the world. Korea is also making great efforts to develop technology to leap forward as a hydrogen economy powerhouse. In particular, the world's No. 1 hydrogen vehicle penetration rate is proof of this. However, the construction of hydrogen refueling stations is being delayed. The biggest delay factor is the public opposition. As such, policies without public support cannot be successfully implemented and are not sustainable. Therefore, this study intends to analyze the factors affecting the acceptability of hydrogen refueling stations in favor of and against them. As a research method, the basic factors affecting acceptability were identified by reviewing previous studies, and a questionnaire was designed and investigated based on the established factors. The validity and reliability of the questionnaire were verified, and the hypothesis was verified through correlation analysis. And, using structural equation modeling, a factor model was developed on the acceptability of hydrogen refueling stations. As a result of the study, acceptability defined private acceptability and public acceptability. In the case of private acceptability, it was confirmed that the higher the attitude toward the environment, the higher the level of knowledge about the hydrogen charging station, and the lower the degree of feeling the risk of the hydrogen charging station, the higher the acceptability. In the case of public acceptability, it was confirmed that the higher the benefit, the better the attitude toward the environment, and the lower the risk-taking characteristics of the individual, the higher the acceptability. Therefore, in this study, based on the potential factors verified in previous studies, the main factors affecting the acceptance on hydrogen refueling stations were identified. And the acceptance model was developed using structural equation modeling. This study is expected to provide basic data to seek ways to improve the acceptance of public when implementing national policies such as hydrogen refueling stations, and to be used analysis data for scientific communication.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.1-12
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• 2019

Based on the capabilities of smartphone cameras which have developed rapidly in recent decades, coupled with and the global market penetration rate, it will study the possibility of various international exchanges through smartphone filmmaking. This aims to achieve a civilian-oriented cultural exchange, instead of simply providing capital-oriented exchanges and film production education. The Smartphone Film Workshop was held as an auxiliary event of the Korea-Vietnam Film Festival, which ran from November 17 to 22, 2017. The three-day workshop, which took place within the festival period, drew attention for its international collaboration project between Korean film directors and Vietnamese film students. The researcher conducted practical-based research while participating as a mentor at this workshop. A step-by-step approach to the entire process of production and post-production was administered, including workshop team composition, scenario, and pre-production in Korea such as shooting equipment, schedule, completion of local works, and screening. Through an analysis of exchange cases at international workshops, we will use trial and error as ways to improve and consider the results of cultural exchanges and the effects of future expectations. Taking this empirical case study into account, we anticipate more active international exchanges through the smartphone workshops.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.63-63
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• 2003

This study was carried out to investigate the effects of liquid boar sperm stored at 4$^{\circ}C$ on sperm motility, normal acrosome, and in-vitro fertilization and culture of pig oocytes matured in-vitro. The sperm-rich fraction (30~60 ml) of ejaculate was collected into an insulated vacuum bottle. Semen was slowly cooled to room temperature (20~23$^{\circ}C$) by 2 h after collection. Semen was transferred into 15 ml tubes, centrifuged at room temperature for 10 min at 800$\times$g, and the supernatant solution was poured off. The concentrated sperm was resuspended with 5 ml of lactose, egg yolk and N-acetyl-D-glucosamine (LEN) diluent to provide 1.0$\times$10$^{9}$ sperm/ml at room temperature. The resuspended semen was cooled in a refrigerator to 4$^{\circ}C$ and preserved for 5 days to examine sperm motility and normal acrosome. The medium used for oocyte maturation was modified tissue culture medium (TCM) 199. After about 22 h of culture, oocytes were cultured without cysteamine and hormones for 22 h at 38.5$^{\circ}C$, 5% $CO_2$ in air. Oocytes were inseminated with liquid boar sperm stored at 4$^{\circ}C$ for 2 days after collection. Oocytes were coincubated for 6 h in 500 ${mu}ell$ mTBM fertilization media with 0.2, 1, 5 and 10$\times$10$^{6}$ /ml sperm concentration, respectively. At 6 h after IVF, oocytes were transferred into 500 ${mu}ell$ Hepes-buffered NCSU-23 culture medium for further culture of 6, 48 and 144 h. There were significant differences in sperm motility and normal acrosome among preservation days and incubation times, respectively. The rates of sperm penetration and polyspermy were higher in 5 and 10$\times$10$^{6}$ sperm/ml than in 0.2 and 1$\times$10$^{6}$ sperm/ml. Male pronuclear formation was lower in 0.2$\times$10$^{6}$ sperm/ml than in 1, 5 and 10$\times$10$^{6}$ sperm/ml. Mean numbers of sperm in penetrated oocyte were highest in 10$\times$10$^{6}$ sperm/ml compared with other sperm concentrations. The rate of blastocysts from the cleaved oocytes (2~4 cell stage) was highest in 1$\times$10$^{6}$ sperm/ml compared with other sperm concentrations. In conclusion, we found out that liquid boar sperm stored at 4$^{\circ}C$ could be used for in-vitro fertilization of pig oocytes matured in-vitro. Also, we recommend 1$\times$10$^{6}$ ml sperm concentration for in-vitro fertilization of pig oocytes.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.89-96
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• 2023

In this paper, a ferrosilicon by-product was evaluated to confirm the feasibility of recycling it as supplementary cementitious material of ordinary Portland cement in concrete. Three different levels of replacement ratio (10 %, 20 % and 30 % of total binder) were applied to find which is the most beneficial to be used as a binder. Ferrosilicon concrete was initially assessed at setting time and compressive strength. Durability was evaluated by the resistance to chloride penetration test(RCPT) and alkali-silica reaction(ASR) with a comparison to silica fume concrete due to their similarity in chemical composition. The porosimetry and X-ray diffraction analysis along with energy dispersive X-ray spectroscopy give information on the microstructural characteristics of the ferrosilicon concrete. It was found that 10 % ferrosilicon concrete has higher strength while 20 %, 30 % have lower strength than OPC concrete. However, chemical resistance to chloride attack is higher when replacement is increased. Compared to silica fume, the durability of ferrosilicon might be less efficient however, it is obviously beneficial than OPC. High SiO₂ content in ferrosilicon results in producing more C-S-H gel which could make denser pore structure. Most of the risk of alkali silica reaction to silicate binders through length change tests was less than 0.2 %, and both mortar using ferrosilicon and silica fume showed better resistance to alkali silica reaction as the substitution rate increased.Reuse of industrial waste rather than producing highly refined additives might reduce environmental load during manufacture and save costs.

• Journal of the Korean Geotechnical Society
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• v.23 no.11
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• pp.87-98
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• 2007

For the quick rehabilitation of a fire-damaged tunnel structure, it is the most important procedure to investigate the fire-induced damaged zone rapidly. This study aims to propose a new drilling resistance testing method by which mechanical properties of tunnel concrete lining altered by high temperature can be estimated easily and continuously. Especially, it alms to derive the relationships to estimate mechanical properties of mortar and concrete materials from drilling parameters. To obtain the optimum testing condition, a series of drilling resistance tests were carried out for mortar specimens. When the rotation per minute of drill bit, tile penetration rate and the bit diameter were 1,300 rpm, 1.40 mm/sec, and 10 mm respectively, the deviation of measured drilling resistance forces was minimal. Under the optimum testing condition, the relationships between drilling resistance and mechanical properties of mortar specimens were shown to be very favorable. The concept of replacing a mean value of resistance farces measured during drilling with the resistance energy was proposed to consider the effects of randomly distributed aggregates inside a concrete material on drilling resistance. When the concept was applied to concrete materials, a favorable relationship between actual compressive strength and drilling resistance energy was also successfully derived.

• Korean small business review
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• v.41 no.1
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• pp.53-73
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• 2019

Recently, as the number of shopping facilities has increased, such as complex shopping malls, warehouse type superstores, large fashion outlets, and so on, the conflicts over the opening of large stores between neighboring municipalities are increasing. However, current regulations on the opening of large-scale stores, such as the impact analysis on commercial area, do not adequately reflect the characteristics of new type shopping facilities. In this study, we tried to suggest a rational policy alternative with more realistic suitability by analyzing the characteristics of 'regional shopping facilities' beyond the scope of the municipalities, and analyzing the impact on the regional merchants. The main results of the study are summarized as follows. First, unlike previous researches, which are limited to small business sector, this study presents the results of comprehensively comparing and analyzing the impact on the detailed sectors of the whole distribution market, including the large distribution sector and online distribution sector. Second, in this study, we calculated the total (average) amount of market penetration rate of existing shopping facilities by the entire regional shopping facilities in the Seoul metropolitan area, and this is considered to be of great value in relation to the recognition of problems at the whole level of the metropolitan area and the search for alternative solutions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.9-20
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• 2023

For highway concrete structures, the deterioration of the structure is accelerated due to the increase in the use of deicing materials, and sectional repair work is being frequently carried out to restore performance. However, after the repair work, re-damage such as cracks, delamination, and poor bond performance is exhibited in the repaired sectional area. In this study, overseas repair material requirements were first analyzed, and present domestic requirements were improved repair material performance through field surveys of common concrete structures, laboratory experiments, and test construction on a disused concrete bridge. In addition, performancebased quality requirements were presented so that all materials that meet the required performance can be applied, and different test methods for each material were unified into concrete test methods for consistent test results analysis. The considered performance requirements were compression strength, bending strength, and bond strength for structural properties, and length change rate, crack resistance, thermal expansion coefficient, and elasticity coefficient were for dimensional behavior. For resistance to chloride penetration resistance and freeze-thaw resistance were presented as durability. The proposed requirements for concrete repair materials are expected to contribute to the improvement of the quality of concrete sectional repair work in Korea.

• Korea Trade Review
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• v.48 no.2
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• pp.111-127
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• 2023

While the e-commerce market in Southeast Asia is growing, this study aims to derive factors for establishing an entry strategy for the Cambodian e-commerce market where Korean logistics companies can strategically enter in the future. Cambodia is a country where growth and growth potential in the e-commerce market is steadily increasing based on the high youth population ratio, high smartphone penetration rate, the introduction of convenient payment systems, and government-level e-commerce promotion policies. In this study, Korean logistics companies established detailed promotion strategies by deriving factors necessary for Cambodia's entry into the e-commerce market and analyzing their relative importance. The AHP analysis technique derived three top factors for the entry strategy, and each presented four sub-factors. As a result, the importance was shown in the order of 'Market Factor' (0.556), 'Policy and Institutional Factor' (0.295), and 'Corporate Competency Factor' (0.149). As a result of the sub-factors analysis, the importance was found in the order of "Characteristics and Growth Potential of Distribution Channel" (0.230), "Purchasing Power and Awareness Level of Consumers" (0.176), "Cambodia Government's E-commerce Policy and Institutional Support" (0.122), and "Cambodia Government's Logistics Infrastructure Plan" (0.108). In both the upper and lower factors, the characteristics and growth potential of the Cambodian e-commerce market were important, indicating that Korean logistics companies value market size and growth potential to enter the Cambodian e-commerce market. The results of this study can be used as a guideline to help Korean logistics companies make successful inroads into Cambodia, where the e-commerce market is expected to grow in the future.