• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.390-399
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• 2021

This study analyze the factors that can improve the satisfaction level of college students stable adaptation to college life and education service. It was analyzed whether students' personal characteristics, college life-related characteristics, and changes in college life Adaptation increase the satisfaction of college education service. As a result of analyzing CAT(college adatiation test) differences of 1st survey and 2nd survey in the results of the total 368 students, the graduates of the academic high school showed high academic integration and social integration and the social integration was high in the types of regular admission. As a result of multiple regression analysis with the increase in college education service satisfaction as a dependent variable, the lower the language score, the more positive changes in academic integrity, career identity, college satisfaction, relationship with professors, economic stability, and study keeping stability. Based on these results, various student support programs were proposed to increase the college education service satisfaction of college students.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.1
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• pp.25-36
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• 2021

The honey bee has a crucial ecological status for maintaining the natural ecology system. Pollination mediations by honey bees are recognized as an efficient way to enhance the quality of biological diversity and green areas in the nature and the urban ecological system. However, the population of bee around the world is decreasing and we do not know exactly how bees react to the physical environment in the urban area. This study is a basic research for the improvement of pollination services in the Korean urban ecological system. It aims to induce and review environmental variables which have high relations with the activities of pollination mediation insects in the urban area. The study established a Maxent model using five urban environmental variables that reflect the ecology of Bombus ignitus and the place information where Bombus ignitus appears in 18 spots of Seoul city, and compared with previous research results on Apis millifera. Bombus ignitus preferred places with more natural environments such as mountain forest areas and vicinities of streams. They preferred Stratified Tree Area the most among the vegetation types existing in the urban area. Comparing chicken models, both species saw their response value drop as the building coverage rose. In the case of Apis millifera and Bombus ignitus variables, the response value of both species was high in 10 out of 20 types. The result of this study is expected to provide basic information for improving the pollination services in the Korean urban area and to be utilized as the basic materials for the future urban planning.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.102-109
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• 2021

Recently, an interest in risk calculation methods has been increasing in Korea due to the establishment of classification code for explosive hazardous area on gas facility (KGS CODE GC101), which is based on the international standard of classification of areas - explosive gas atmospheres (IEC 60079-10-1). However, experiments to check for leaks of combustible or toxic gases are very difficult. These experiments can lead to fire, explosion, and toxic poisoning. Therefore, even if someone tries to provide a laboratory for this experiment, it is difficult to install a gas leakage equipment. In this study we find out differences among actual experiments, CFD by using FLACS and calculation based on classification code for explosive hazardous area on gas facility (KGS CODE GC101) by comparing to each other. We develpoed KGS HAC (hazardous area classification) program which based on KGS GC101 for convenience and popularization. As a result, actual gas leak, CFD and KGS HAC are showing slightly different results. The results of dispersion of 1.8 to 2.7 m were shown in the actual experiment, and the CFD and KGS HAC showed a linear increase of about 0.4 to 1 m depending on the increase in a flow rate. In the actual experiment, the application of 3/8" tubes and orifice to take into account the momentum drop resulted in an increase in the hazardous distance of about 1.95 m. Comparing three methods was able to identify similarities between real and CFD, and also similarities and limitations of CFD and KGS HAC. We hope these results will provide a good basis for future experiments and risk calculations.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.308-312
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• 2022

3D printing technology, which creates a physical object by various material deposition, has been widely used in recent years in the manufacturing field because of its advantages. Among the various printing technologies, droplet-based 3D printing technology (e.g., Polyjet^®) enables a high-resolution printing using photocurable materials such as hydrogels. Depending on the degree of light exposure, ejected photocurable droplets may have different properties (e.g., viscosity) until they collide with the substrate and it leads to the different spreading behaviors of the droplets (i.e., impact, spreading, and recoiling) during deposition on the substrate. In this study, experimental observation and analysis of the changes in hydrogel droplet viscosity and spreading behavior according to the light exposure were carried out based on high-speed image processing.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.105-115
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• 2020

Recently, due to a decrease in the school age population, it is expected that there will be great difficulties in recruiting students. The dropout rate for the last three years of four-year universities nationwide announced in www.academyinfo.go.kr has been continuously increasing at 4.1% (2016), 4.3% (2017), and 4.6% (2018). It has emerged as the biggest issue facing the university. In this study, through a large-scale empirical study at H University, an analysis of the dropout intention of college students and educational factors affecting their intentions were derived. First, as a result of analyzing the intention to drop out, the dropout intention of students in the engineering department was higher than in the humanities, and it was higher in the upper grades. Students from specialized high schools were higher than general high schools, and the students who raised the tuition fees were higher than those who were not. As a result of factor analysis on dropout intention, it was analyzed that class difficulty, major satisfaction, parent satisfaction, internationalization satisfaction, and college education performance satisfaction had a significant effect on dropout intention.

• The Korea Journal of Herbology
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• v.29 no.2
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• pp.55-60
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• 2014

Objectives : The aim of this study was to evaluate whether herb mixture extract (HME) would affect allergic contact dermatitis induced by 1-chloro-2,4-dinitro-chlorobenzene (DNCB) in mice. For this, the level of blood IgE was identified. To evaluate anti-inflammatory effect of HME, we tested HMC-1 cells stimulated by PMA+A231867. Methods : In order to evaluate allergic contact dermatitis effects we observed HME on contact-hypersensitive skin of Balb/cmice induced by 0.5% DNCB and measured concentration of IgE in blood of Balb/c mice. In order to evaluate anti-inflammatory effect of cytokine expression we used the method of enzyme-linked immunosorbent assay. Results : We confirmed deep wounds, erosions, progress of keratinization and drop out of dead skin cells from Balb/c mice induced by 0.5% DNCB. We also observed a remarkable decrease in symptoms of atopic dermatitis in the group that received injection of 200mg/kg HME. In addition, in the measurement outcome for IgE concentration in blood, we confirmed that IgE concentration was increased by treatment with DNCB only, while it was markedly decreased by treatment with HME. We confirmed that cytokine expression decreased through enzyme-linked immunosorbent assay and pERK, pJNK, and pp38 also decreased through western blot test Conclusions : According to the above results, HME has some effect on alleviating symptoms of allergic contact dermatitis and has anti-inflammatory effects.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.35 no.1
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• pp.24-37
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• 2022

Objectives : The purpose of this literature review is to analyze process of manufacture and formulation and toxicity of Geumgweyoryak(金匱要略)'s external applicants for modern and safe using. Methods : This study used the Geumgweyoryak(金匱要略) reprinted by Zhao Kaimei(趙開美) as basic data for a understanding of the manufacture and formulation and toxicity for external applicants. Among the 25 chapters, the 22 chapters were studied except for the last three chapters, which are known to be written by later writers. Based on the above, Geumgweyoryeok(金匱要略)'s external applicants was analyzed the process of manufacture, formulation and the toxicity. Results : There are 11 types of external applicants of Geumgweyoryak(金匱要略). Washing method(洗法) was used 2 times, Drop method(瀝法) was used 1 time, Smoke method(熏法) was used 2 times, Rubbing method(摩法) was used 1 time, Plaster method(敷法) was used 2 times, Invading method(浸法) was used 1 time, Suppository method (坐法) was used 2 times, Flatiron method(烙法) was used 1 time. According to classified the modern formulation, there are 4 types of powder formulation, 4 types of liquid formulation, 2 types of suppository, and 1 type of Semi-solid formulation. Especially toxic drugs, such as Realgar(雄黃) or Hydrocerussite(鉛粉), should be careful. When Realgar(雄黃) smokes, a toxic substance called AS2O3 can come out. Hydrocerussite(鉛粉) can cause lead poisoning. Lead increases the risk of anemia, dehydration, and lead neuropathy when chronically exposed. Conclusion : We supposed that this study can serve as a basic data to help clinical Korean doctors to use the prescription for external applicants more safely and to easily apply it in the form of external applicants.

• Particle and aerosol research
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• v.18 no.3
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• pp.79-86
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• 2022

Many commercial air purifiers currently have deployed granular activated carbon (GAC) filters for removing volatile organic compounds in the indoor air. GACs are generally used to remove gaseous contaminants in the air through adsorption by the inner surfaces of pores. In addition, airborne particles can be also filtered by the surface adsorption of the GACs, which can improve the life-time of the particulate filters. In this study, the filtration efficiency of GACs to ultrafine particles through surface adsorption was investigated at different volume flow rates by deploying a continuous particle filtration system. The polydisperse sodium chloride (NaCl) particles were generated by a set of an atomizer and a diffusion dryer, and then mixed with particle-free air at different volume flow rates. The penetration of ultrafine particles and pressure drop for each experimental condition were measured to figure out the effect of the volume flow rate on the surface adsoprtion of the GACs to particles, ~ 2 mm. The particle filtration efficiency of the GACs decreased as the volume flow rate increased from 4 to 14 lpm. However, the 5 times thicker GAC filter layer decreased the penetration of ultraparticles than a preious study. The filtration efficiency of the single granule was also higher than the previous result in the literature with smaller granule filter materials.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.499-511
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• 2022

In this study, a vertical drop test was carried out to identify the performance of flexible wire rope rockfall protection fence by 100 kJ rockfall energy according to ETAG 027. The flexible wire rope, which consists of wire rope and spring. is especially enhanced the elasticity and flexibility so that it can be longer elongated when the rope is impacted by rockfall compared to original wire rope, and that results longer increase of contact time between rockfall and wire rope and increase rockfall energy absorption capability and decreases rockfall impact force. The test results shows that the plastic deformation occurred in middle post and the final deflection of the middle post was 1.15 m, which is lower than 2.0 m determined by ETAG 027. This vertical test verified the flexible wire rope rockfall protection fence can successfully absorb 102.9 kJ rockfall energy.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.599-616
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• 2021

The semi-submersible with three circular columns is an original concept of efficient multifunctional platform, which can be used for marginal oil, gas field, and Floater of Wind Turbines (FOWT). However, under certain flow conditions, especially in uniform current with specific velocities, the eddies will alternatively form and drop behind columns, resulting in the fluctuating lift force and drag force. Consequently, the semi-submersible will subject to the Flow-Induced Motions (FIM). Based on the Detached Eddy Simulation (DES) method, the numerical studies were carried out to understand the FIM characteristics of the three-column semi-submersible at two different parameters, i.e., current incidences (0°, 30°, and 60°-incidences) and reduced velocities (4 ≤ U_r ≤ 14). The results indicate that the lock-in range of 6 ≤ U_r ≤ 10 for the transverse motions is presented, and the largest transverse non-dimensional nominal amplitude is observed at 60°-incidence, with a value of A_y/D = 0:481. The largest yaw amplitude A_yaw is around 3.0° at 0°-incidence in the range of 8 ≤ U_r ≤ 12. The motion magnitude is basically the same as that of a four-column semi-submersible. However, smaller responses are presented compared to those of the three-column systems revealing the mitigation effect of the pontoon on FIM.