• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.4
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• pp.215-222
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• 2019

The heat conduction problem with discontinuous material coefficients generally consists of the conservative equation, boundary condition, and interface condition, which should be additionally satisfied in the solution procedure. This feature often makes the development of new numerical schemes difficult as it induces a layered singularity in the solution fields; thus, a special approximation is required to capture the singular behavior. In addition to the approximation, the construction of a total system of equations is challenging. In this study, a wedge function is devised for enriching the approximation, and the interface condition itself is embedded in the moving least squares(MLS) derivative approximation to consistently satisfy the interface condition. The heat conduction problem is then discretized in a strong form using the developed derivative approximation, which is named as the interface immersed MLS difference method. This method is able to efficiently provide a numerical solution for such interface problems avoiding both numerical quadrature as well as extra difference equations related to the interface condition enforcement. Numerical experiments proved that the developed numerical method was highly accurate and computationally efficient at solving the heat conduction problem with interfacial jump as well as the problem with a geometrically induced interfacial singularity.

• Health Policy and Management
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• v.29 no.1
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• pp.58-67
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• 2019

Background: In this study, we aimed to investigate the drinking behaviors and drinking-related problems of college students in South Korea to produce national alcohol statistics. Methods: We carefully examined the questionnaires and previous research developed in the previous research project and selected questions that reflect the special environment and culture of college students. In order to stratify a nationally representative sample of college students, the distribution of students around the country were found through the educational statistics database of the Korea Educational Development Institute. Based on this information, we conducted a survey in collaboration with Gallup (Korea) to survey and analyze the drinking behaviors of 5,024 Korean students. Results: A nationwide cross-sectional survey was conducted in 2017, for Korean college students. A total of 5,024 students were recruited and analyzed. The monthly drinking rate was 78.0% for male students and 72.9% for female students. The high-risk drinking rate was 23.3% for male students and 17.2% for female students. The most popular category for number of drinks per drinking session was 'more than 10 glasses' per drinking session for both male (44.1%) and female (32.8%). On the alcohol use disorders identification test, the greatest proportion of male students were in the high-risk drinking category (score 8 to 15) 43.8%, followed by the 'low-risk drinking' (score 0 to 7) in 43.6%, 'alcohol abuse' (score 16 to 19) 7.2%, and 'alcohol dependence' (greater than 20) 5.4% categories, respectively. For female students, the greatest proportion of female students were in the 'low-risk drinking' in 49.6%, followed by 'high-risk drinking' 37.1%, 'alcohol abuse' 8.4%, and 'alcohol dependence' 4.9% categories, respectively. Conclusion: The results of the study showed that the drinking behavior of Korean college students was excessive. Overall, it was found that the college population has a greater high-risk drinking behaviors than general adult population. Furthermore, these problem drinking behaviors were prominent among female college students. Results from the present study suggest that it is necessary to monitor the drinking behavior of college students with constant interest and to prepare policies and strategies suitable for these circumstances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.417-426
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• 2019

This study examined to offer practical implications for the bullying for the prevention and response in early childhood education at the scene of the bullying that occur by to confirm the perception of the bullying to pre-service early childhood teachers. The survey questionnaire was completed by 313 pre-service early childhood teachers. SPSS Win program was used to perform frequency analysis, ANOVA. (1)The perception of bullying were significantly different according to grade and experience of child care practice, classroom observation, education program for taking preventive measure. (2)Teachers' perception about the action that can be seen as bullying followed by 'apply the violence, such as kicking, or were frequent', 'shared in things that often prevents','often to another carrier or shame in front of a friend'. (3)Perception about characteristics of bullying Perpetrators was 'aggressive behavior and talk much' and perception about characteristics of bullying victims was 'shy and not much'. (4)The reason of bullying perpetrators was 'Just for fun without a special reason' and the cause of bullying victims was 'problem of parents' child-rearing attitudes and home environment'. (5)Important institutions to combat bullying prevention followed by teacher, parents and family, community and the nation, preschool educational institution. Teachers guidance content of combat and prevent bullying was 'to be isolated from the class to infants continue to monitor'. Parents guidance content of combat and prevent bullying was 'communicate a lot and attention to children'. Early childhood education institutions guidance content of combat and prevent bullying was 'operations to come up with the bullying prevention education in educational time'. This study indicated that it is necessary to make efforts for increasing perception of bullying in pre-service early childhood teachers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.667-675
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• 2021

The purpose of this study is as follows: First, to analyze the spatial structure of Jeju by analyzing the rate of parking demand and supply; Second, to determine the parking service imbalance between regions; and third, to elucidate the causes of this spatial structural parking service imbalance and provide effective measures. Due to the rapid population and tourism growth, Jeju is suffering from traffic congestion and serious parking problems. For this, the ways to efficiently utilize the existing parking spaces were identified through spatial structure analysis based on the parking demand and supply in the Jeju area. As short-term policy, the following changes were proposed: switching to small-scale eup or myeon blocks of parking space, use of shared parking system, and repairing side streets in residential areas. As mid-to-long-term policy, it is linked to other means of transportation as follows: parking demand management policy through modal share by reorganizing public transportation routes or expanding traffic facilities; securing park-and-ride lots; and different parking pricing for different time periods. To implement these policies, each area of the public sector, private sector, and private-public partnership should develop the bond of sympathy by areas and participants.

• Journal of Legislation Research
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• no.55
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• pp.7-56
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• 2018

This paper deals with the legal meaning and issues of street performances. The key elements in the legal sense of street performances (or artistic performances) are 'public places' and 'artistic activities'. Therefore, as far as belongs to "artistic activities in public places", we can call them in principle as street performances regardless of its level of art, whether they are paid or not, size of performances or genre of artistic activities. Street performances are a way for anyone to freely participate and enjoy art by being performed on open places. In addition, street performances can be seen as more popular and democratic artistic acts than mainstream art culture in that anyone can become street performers. Although street performances are in vogue and becoming a universal cultural phenomenon, they do not appear to be legally organized yet. However, we don't have to strictly regulate street performances on the grounds that they are something different and special. Instead, they should let their street performances be freely performed and enjoyed in accordance with the constitutional law that guarantees the freedom of art or the freedom of artistic expression. Of course, it is necessary to modify the relevant laws on key issues raised regarding street performances. Finally, for street performances to be well established as cultural phenomenon, it should be harmonized that efforts to observe the law and orders by street performers, mature rituals and cultural tolerances of citizens who enjoy street performances, and efforts to realize the purpose of cultural countries and to promote street performances by governments.

• Conservation Science in Museum
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• v.25
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• pp.51-62
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• 2021

The Belt with Rhinoceros-Horn Ornaments(known as a seodae in Korean) from the family of Princess Deokon's descendants housed in the National Hangeul Museum underwent emergency treatment for a special exhibition in 2019 upon the request of the National Hangeul Museum. Priority was given to the restoration of the original form of the severely damaged belt and the repair of its detached horn ornaments. Prior to the conservation treatment, researchers conducted a theoretical study of the belt with rhinoceros-horn adornments to learn the names of its structural components and the changes in form that the type experienced by period, thereby establishing a plan for conservation treatment and setting a direction. Among the belts worn by officials from the Joseon dynasty, rhinoceros-horn ornaments were attached to those of officials of the first rank and were considered the most precious behind the king's belt with its jade ornaments. The rhinoceros horn adorning the belt is classified into three categories according to quality. This belt has horn adornments of the highest quality, falling under the "grape design" category with dark brown dots concentrated in the center. The belt has a rectangular shape and lacks a buckle, reflecting a popular form from the nineteenth century. The structure of the belt was identified over the process of conservation treatment, offering information about its method of production. In addition, comparison of the relic with belts with rhinoceros-horn ornaments depicted in Joseon-period portraits of officials allowed the identification of changes in formal features and the detailed structures of belts with rhinoceros-horn ornaments by period. It confirmed that the belt subject to conservation treatment shows the features of belts with rhinoceros-horn ornaments produced in the nineteenth and twentieth centuries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.651-659
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• 2020

The objective of this study is to provide high-quality medical service, by understanding the characteristics and death risk factors of patients at V long-term care hospital, that has established and operated the cooperative treatment system in connection with a public institution, the S veterans hospital. A follow-up survey targeting a total of 850 discharged patients was conducted for the year 2017. Average age of patients was 79.2 years, with 86.4% belonging to the 70 years or over group. The men of national merit were 75.4%, which was more than three times higher than general patients. Hospitalization for 180 days or more was 46.4%, which was higher than general long-term care hospitals (37%). The major death risk factors were age and the number of hospitalized days. Our data indicate that transfer to S veterans hospital results in providing quicker treatment and higher effectiveness of the numerous recovery therapies. We therefore propose that the cooperative treatment system should be expansively operated to increase the quality of happy life, by alleviating the health of patients with chronic diseases in a long-term care hospital.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.59-63
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• 2021

To study for germination rate of apple artificial seeds encapsulated with 2% alginic acids, the rates of germination for artificial seeds of various embryos with partial elimination of cotyledon measured by adding 80 mg/L gibberellic acid or/and nutritional media. The germination rate of artificial seeds produced embryo with 3/4 cotyledon (3/4 CE), embryo with 1/2 cotyledon (1/2 CE), embryo with 1/4 cotyledon (1/4 CE), and embryo without cotyledon (NCE) were gradually decreased with compare to normal embryo, but it's considerably recovered on the alginic acid containing MS solution or/and 80 mg/L GA3. In special, the low frequency (55.81%) of germination for artificial seeds of 1/2 cotyledon embryo with alginic acid was increased by treatment with combination of alginic acid, 3% sucrose, and 80 mg/L gibberellic acid (98.74%). In case of embryo without cotyledon, the low frequency of embryo without cotyledon (24.44%) in alginic acid almost recovered to 82.45% in alginic acid with MS solution and 80 mg/L gibberellic acid. The results shown that the germination of embryo was decreased by the removal of cotyledon, and demonstrated that the low rate of germination could be considerably increased by adding GA3 (80 mg/L) or/and nutrition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.53-59
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• 2021

The marine transport industry generally applies new technologies later than other transport industries, such as airways and railways. Vessels require efficient operation, and their performance and lifespan depend on the level of maintenance and management. Many studies have shown that corrective maintenance (CM) and time-based maintenance (TBM) have restrictions with respect to enabling efficient maintenance of workload and cost to improve operational efficiency. Predictive maintenance (PdM) is an advanced technology that allows monitoring the condition and performance of a target machine to predict its time of failure and helps maintain the key machinery in optimal working conditions at all times. This study presents the development of a marine predictive maintenance (MPdM; maritime predictive maintenance) method based on applying PdM to the marine environment. The MPdM scheme is designed by considering the special environment of the marine transport industry and the extreme marine conditions. Further, results of the study elaborates upon the concept of MPdM and its necessity to advancing marine transportation in the future.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.19-28
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• 2021

Corrosion is the degradation of metals by reaction with the environment. It is difficult to completely remove. Corrosion proceeds rapidly after the protective barrier is destroyed, and several reactions occur that alter the composition and properties of the metal surface and local environments, such as diffusion of metal cations into the matrix, the formation of oxides, and local pH changes. The study of corrosion of steel and iron is of theoretical and practical interest and is receiving considerable attention. Acid solutions, which are widely used in industrial pickling, acid descaling, cleaning and acidification of oil wells, require the use of corrosion inhibitors to suppress corrosion attacks on metallic materials. Physical removal of rust requires expensive special equipment, and chemical removal of it can cause corrosion or shorten the life of the metal. In this study, an eco-friendly rust cleaner was developed using cosmetics and food materials by applying the concept of perm reducing agent and chelate, and applied to remove rust from industrial and hot water pipes and various industrial devices. As a result, it was found that rust cleaners remove rust more effectively and safely compared to conventional treatment methods. At the same time, the rust removal efficiency was 1.75 to 2.5 times better for industrial piping and 1.56 to 2.2 times better for boiler hot water than conventional methods.