• Journal of the Korean Geotechnical Society
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• v.38 no.4
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• pp.33-45
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• 2022

A series of model tests were performed in this study to demonstrate the clogging mechanism created during the installation of a compaction pile to improve soft ground. The application of an air-jet to extrude sand or aggregates from a casing during the installation of a compaction pile imposes a remarkably high-pressure difference between the composite soil layers of clay and sand (or aggregates), resulting in severe clogging. Therefore, a one-dimensional testing system was developed to simulate composite soil layers consisting of clay and sand (or aggregates) and to apply a high-pressure differential at both boundaries, thus replicating the extrusion process used in compaction pile installation. Herein, the performance of two construction materials for compaction piles of crushed stone and grading-controlled aggregates was compared. A series of one-dimensional model tests were performed under multiple pressure settings, with clogging depth and permeability measured in each case. Results indicate that, blinding clogging mechanisms and blocking defined by previous studies were observed for crushed stone, and a new mechanism of "infiltration" was revealed and defined. Whereas, the controlled aggregates performed excellently against clogging because only blinding was observed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.4
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• pp.341-353
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• 2022

Pipelines are buried in urban area, and the position (depth and orientation) of buried pipeline should be clearly identified before ground excavation. Although various geophysical methods can be used to detect the buried pipeline, it is not easy to identify the exact information of pipeline due to heterogeneous ground condition. Among various non-destructive geo-exploration methods, ground penetration radar (GPR) can explore the ground subsurface rapidly with relatively low cost compared to other exploration methods. However, the exploration data obtained from GPR requires considerable experiences because interpretation is not intuitive. Recently, researches on automated detection technology for GPR data using deep learning have been conducted. However, the lack of GPR data which is essential for training makes it difficult to build up the reliable detection model. To overcome this problem, we conducted a preliminary study to improve the performance of the detection model using finite difference time domain (FDTD)-based numerical analysis. Firstly, numerical analysis was performed with homogeneous soil media having single permittivity. In case of heterogeneous ground, numerical analysis was performed considering the ground heterogeneity using fractal technique. Secondly, deep learning was carried out using convolutional neural network. Detection Model-A is trained with data set obtained from homogeneous ground. And, detection Model-B is trained with data set obtained from homogeneous ground and heterogeneous ground. As a result, it is found that the detection Model-B which is trained including heterogeneous ground shows better performance than detection Model-A. It indicates the ground heterogeneity should be considered to increase the performance of automated detection model for GPR exploration.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.207-220
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• 2021

The purpose of the study is to investigate the application and utility of emergency rescue education and derive limitations, improvements and development directions of university education based on the field experience of 119 emergency medical technician(EMT)s. The research subjects were six new 119 emergency medical technician(EMT)s within three years of starting their first-aid service in the field. After conducting in-depth narrative interviews, the analysis was performed using Colaizzi method. The 82 formulated meanings were derived from significant statements. From formulated meanings, 23 themes, 4 theme clusters, 2 categories were identified. The four theme clusters were 'The effectiveness of university education', 'The limitations of university education', 'The direction of improvement in educational methodology' and 'The direction of improvement in educational contents. University education has been helpful overall, but limitations are observed at the same time, suggesting that it should be developed through the improvement of educational methodologies (i.e. problem-based learning, field case review, education through role-playing, simulation education, strengthening skill ect.) and educational content (i.e. training tailored to the field, education focused on trauma or cardiac arrest, expansion of triage education in disaster management, reinforcement of education on-site safety, education on special patients, diverse guidance and faculty for different perspectives).

• Journal of Korea Entertainment Industry Association
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• v.15 no.3
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• pp.89-99
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• 2021

A brand community refers to a group of people who have a passion and loyalty for the brand, and is attracting attention as an effective marketing strategy to increase brand equity because it actively tends to support and promote the brand without expecting compensation. The objective of this study is to identify factors that are needed for sustainable brand community management. Existing studies on brand community management have mainly been conducted by quantitative methods measuring consumer satisfaction and dissatisfaction towards brand community activities, however, this study applied qualitative methods using means-end chains and laddering approaches in order to deeply identify a consumer's desired value on brand community activities. An in-depth interview of 41 members of BTS ARMY, a representative example of brand community, has been conducted and analyzed. The result of this study is as follows. In order to encourage active brand community activities, it is important to provide brand community members with a variety of high-quality brand-related content for a unique aesthetic experience, and a forum where all members can interact and exchange information and ideas to enhance brand value and experience. Finally, to nurture a strong brand community as a partner to co-create brand equity, rather than just a fan community, it is needed to build an environment that fosters opportunities for brand community members to increase self-respect and fulfillment through their brand community activities.

• Journal of Environmental Health Sciences
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• v.48 no.5
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• pp.282-289
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• 2022

Background: Airborne fungi are ubiquitous in the air and exposure to an airborne fungus can be a significant risk factor. The composition of fungi has been potentially important for human health, especially for respiratory diseases like asthma and atopic dermatitis. Therefore, we attempted to ascertain what kind of airborne fungi affect human health at a nationwide level. Objectives: This study was carried out to provide information on indoor fungi distribution at multi-use facilities throughout South Korea. Methods: We classified our data by region and public facility after collection, cultivation, and identification via the sequencing of the ITS (internal transcribed spacer) region. We investigated whether or not the proliferation of HaCaT cells was affected by the identified airborne fungi. Results: In our data, the most isolated airborne fungi by region were Penicillium spp (Seoul, Daegu), Periconia sp (Gyeonggi-do), Iprex sp (Gangwon-do), Phanerochaete sp (Busan), Bjerkandera sp (Gwangju), and Aspergillus sp (Jeju-do). In the public facilities, the most detected fungi were Cladosporium sp (public transport), Penicillium sp (apartment house, retail market, financial institution, karaoke room), Bjerokandera sp (underground parking lot, public toilet, medical institution), Periconia sp (retail store), and Fusarium sp (general restaurant). Next, we selected twenty airborne fungi to examine their cytotoxicity and proliferation of human skin cells. In this experiment, the proliferation of the cells was influenced by most of the identified fungi. In case of the cytotoxicity test, most genera except for Rhodotorula sp and Moesziomyces sp showed cytotoxicity in HaCaT cells. Conclusions: The distribution of mold in the indoor air in multi-use facilities in South Korea differs from region to region, and this is an indicator that should be considered in future health impact studies. In addition, as a result of culturing about 20 types of bacteria dominant in indoor air, it was found that most (90%) inhibit the growth of skin cells, which can be harmful to health. An in-depth study of the health effects of floating fungi is needed.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.368-378
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• 2020

Purpose: Vitamin D deficiency may cause bone loss and increased inflammation, which are well-known symptoms of periodontal disease. This study investigated whether serum 25-hydroxyvitamin D (25(OH)D) levels are associated with periodontal disease status and tooth loss. Methods: Cross-sectional data from 5,405 individuals aged ≥50 years (2,253 males and 3,152 females) were obtained from the 2008-2010 Dong-gu study, a prospective cohort study of risk factors for chronic diseases. Periodontal examinations were conducted to evaluate the number of remaining teeth, the periodontal probing depth (PPD), the clinical attachment level (CAL), and bleeding on probing. The percentages of sites with PPD ≥4 mm and CAL ≥4 mm were recorded for each participant. The severity of periodontitis was classified using the Centers for Disease Control and Prevention and the American Academy of Periodontology case definitions. Serum 25(OH)D levels were classified as reflecting severe deficiency, deficiency, insufficiency, or sufficiency. Multivariate linear regression analysis was performed to assess the associations of serum 25(OH)D levels with periodontal parameters and the number of remaining teeth after adjusting for confounders including age, smoking status, alcohol consumption status, month of blood collection, and physical activity. Multivariate logistic regression was used to evaluate the association between serum vitamin D levels and severe periodontitis. An overall statistical analysis and a stratified analysis by sex were performed. Results: Overall, the rates of severe deficiency, deficiency, insufficiency, and sufficiency were 6.5%, 67.9%, 22.4%, and 3.2%, respectively. After adjustment for confounders, vitamin D levels were directly associated with the number of remaining teeth, an association that was significant in males, but not in females. Sufficient serum 25(OH)D was associated with a low frequency of severe periodontitis. Conclusions: This population-based cross-sectional study indicates that low serum 25(OH) D is significantly associated with tooth loss and severe periodontitis in Koreans aged 50 years and older.

• Korean Association of Arts Management
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• no.57
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• pp.33-58
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• 2021

The purpose of this study is to understand the impact of the subscription economy on the contemporary art market in terms of creation, consumption and distribution of artwork. To accomplish the aim of this study, we conducted a case study of Artnomic Gallery K borrowing the theoretical perspective from Alexander(2003)'s Modified Cultural Diamond model. In this paper, we collected data through reviewing the secondary document and conducting in-depth interviews with 10 experts and consumers in the art market. As a result, the subscription economy eases the traditional art trade, which is heavily focused on a small number of market arts, by encouraging artists to create various works. The transition to subscription in the purchase of art contributes to lowering the barriers to entry into the art market by reducing the financial burden on consumers in terms of consumption. In terms of distribution, this founding of this article shows that the experts of Gallery K are the main actors in selecting the works that consumers subscribe to. Therefore, in this study, it is of academic significance to discuss that the filtering effect of the distribution system emphasized by Alexander(2003) is effective even in the art trading system to which a new form of economic activity - the subscription economy - is applied.

• Journal of The Korean Association For Science Education
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• v.42 no.6
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• pp.567-578
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• 2022

In this study, we examine whether the description of the elementary science curriculum guide, the concept of evolution, and the beliefs of teachers affect the teaching practice in classes related to adaptation of elementary school teachers. First, we examined the alternative concept among the sentences described in the bio-adaptation-related unit of the 2009 Elementary Science Curriculum Teacher's Guide and identified the effects of this description on the teaching practice of elementary school teachers. Next, six elementary school teachers were classified according to the results of the evolutionary concept test paper and the evolutionary belief test paper, and based on the class recording data and interview data, whether there is a difference in teaching execution. As a result, it was confirmed that there were a total of 18 descriptions corresponding to the concept of evolutionary alternatives in the analysis of instruction descriptions, and that these descriptions influenced elementary school teachers' adaptation concepts and teaching practice. Next, the group with high and low levels of evolution differ in the areas of "recognition of importance in the unit, distinction between adaptation concepts in the general sense and adaptation concepts in the biological sense, errors in the class," and "recognition of evolutionary education needs in the elementary curriculum." This study is meaningful in that it qualitatively confirms the research on the evolution concept of elementary school teachers, which has been approached quantitatively, and in-depth, confirms how the description, evolution concepts, and evolutionary beliefs affect elementary school teachers' biological adaptation concepts.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.51-64
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• 2022

Along with the urbanization, the risk of urban flooding due to climate change is increasing. Flood regulation, one of the ecosystem services, is implemented in the different level of function of flood risk mitigation by the type of ecosystem such as forests, arable land, wetlands etc. Land use changes due to development pressures have become an important factor in increasing the vulnerability by flash flood. This study has conducted evaluating the urban flood regulation service using InVEST UFRM(Urban Flood Risk Model). As a result of the simulation, the potential water retention by ecosystem type in the event of a flash flood according to RCP 4.5(10 year frequency) scenario was 1,569,611 tons in urbanized/dried areas, 907,706 tons in agricultural areas, 1,496,105 tons in forested areas, 831,705 tons in grasslands, 1,021,742 tons in wetlands, and 206,709 tons in bare areas, the water bodies was estimated to be 38,087 tons. In the case of more severe 100-year rainfall, 1,808,376 tons in urbanized/dried areas, 1,172,505 tons in agricultural areas, 2,076,019 tons in forests, 1,021,742 tons in grasslands, 47,603 tons in wetlands, 238,363 tons in bare lands, and 52,985 tons in water bodies. The potential economic damage from flood runoff(100 years frequency) is 122,512,524 thousand won in residential areas, 512,382,410 thousand won in commercial areas, 50,414,646 thousand won in industrial areas, 2,927,508 thousand won in Infrastructure(road), 8,907 thousand won in agriculture, Total of assuming a runoff of 50 mm(100 year frequency) was estimated at 688,245,997 thousand won. In a conclusion. these results provided an overview of ecosystem functions and services in terms of flood control, and indirectly demonstrated the possibility of using the model as a tool for policy decision-making. Nevertheless, in future research, related issues such as application of models according to various spatial scales, verification of difference in result values due to differences in spatial resolution, improvement of CN(Curved Number) suitable for the research site conditions based on actual data, and development of flood damage factors suitable for domestic condition for the calculation of economic loss.

• Industry Promotion Research
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• v.7 no.4
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• pp.53-61
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• 2022

This study is a phenomenological study on the dream insight process of intern counselors. The purpose of this study is to promote growth as a professional counselor based on the process of giving meaning to and recognizing their experiences through insight into the unconscious. Therefore, we used dream-integrated art therapy to have a process of recognizing unconscious dreams that clearly express expectations for oneself, others, and the world, and to explore this process more flexibly. The research participants selected three students enrolled in the master's and doctor's courses from among the applicants who applied through public relations and adopted the phenomenological Giorgi research method for data collection and analysis through in-depth interviews with the research participants. The main research results are as First, the intern counselors had a motive for wanting their own unconscious insight through dream-integrated art therapy and were able to gain insight into the problems revealed in their unconscious through dreams, music, and art media. Second, it was found that the intern counselors felt a deepening of concentration and comfort through recent dreams, music, and art media in common. Third, as a defense mechanism that was revealed without the combination of dream integrated art therapy, the avoidance tendency of not wanting to reveal oneself was common, but this showed a gradual decrease. Fourth, it was reported that intern counselors gained flexibility for themselves about the future growth direction had an opportunity to accept themselves, and had a plan for the future direction to become professional counselors. Therefore, it is suggested that follow-up studies using various media, studies to verify the effectiveness of the dream integration program, and various case studies are necessary.