• Journal of Korea Entertainment Industry Association
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• v.15 no.3
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• pp.289-295
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• 2021

Today, the most important factor affecting the quality of human life is thought to be due to the environment. The importance of environmental monitoring systems to improve human life and improve welfare as the magnitude of the damage increases year by year due to the rapid increase in the frequency of hail, typhoons, collapse of incisions, landslides, etc. Is increasing day by day. Among environmental problems, problems caused by water quality have a very high proportion, and as there is a growing concern that the scale of damage will increase when water pollution accidents occur due to urbanization and industrialization, the demand for social water safety nets is increasing. have. In the last 5 years, 259 cases of water pollution (Han River 99, Nakdong River 31, Geum River 25, Seomjin River and Yeongsan River 19, and 85 others) have occurred in the four major river basins. Caused damage. Therefore, it is required to establish a water quality environment management strategy system based on big data that can minimize the uncertainty of the water quality environment by expanding the target of water quality management from the current water quality management system centered on the four major rivers to small and medium-sized rivers, tributaries/branches, and reservoirs. In this paper, we intend to construct and analyze a water quality monitoring system based on big data that can present useful water quality environment information by analyzing the water quality information accumulated for a long time.

• Journal of Families and Better Life
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• v.27 no.6
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• pp.65-82
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• 2009

The following research aimed to determine the effect of stress among middle school students on their addiction to the Internet. This research's target was a group of male students who had a high probability of getting addicted to the Internet while playing c/t games. The study distributed 357 questionnaires and used 340 copies, which meant discarding 17 copies that were considered inadequate. The research results are as follows: First, there appeared subordinate factors in the stress suffered by the students. These included stress from their families, from conflicts with their teachers, from the living environment, current schoolwork and future course in college, insecurity over their physical appearance, bullying from other students, and relationships with friends. Among these factors, stress caused by conflicts with teachers and family was the most frequently cited, while stress from their friends was the least cited. The motive in using the Internet was found to be bound with several factors. These include: a form of diversion, a way to communicate with others, a means in coping with loneliness, a source of news and information, a form of passing away time, a kind of habit, and others. Among these motives, passing away time and indulging a habit were cited the most, followed by news and information search, and a form of diversion. Second, as a subordinate factor in Internet addiction, the following were cited: formation of tolerance, health issues, occurrence of problems related to daily life, satisfaction or a pleasant sensation, withdrawal, cover-up on the use of the Internet, and formation of virtual interpersonal relationships, and others. Among these, the formation of tolerance came out the highest, followed by health issues, daily life, and problems related to daily life. Third, in terms of the effects of stress on the motive in using the Internet, the research found that the more the students felt stressed out by conflicts with their teachers and family, the more they tended to use the Internet to communicate with others, to cope with loneliness, to obtain newsI and information, to passawaytime, and to indulge a habit Also, the more they felt stressed out by the living environment, the more they tended to use the Internet to communicate with others, to cope with loneliness, and use news and information. The more they felt stressed out by their schoolwork and future course in college, they tended to use the Internet as a form of diversion and to secure news and information. The more they felt stressed out by their insecurity over their physical appearance and being victimized by bullies, the more they tended to use the Internet to cope with loneliness. Fourth, as for the effect of several variables on student addiction to the Internet, the study found that the more students felt stressed out by their living environment, by schoolwork and future course in college, by their physical appearance, and bullying from other students, the more they used the Internet as a form of diversion, a communication tool, and as a means of passing away time or indulging a habit. The study came up with the finding that the more the students used the computer and the Internet, the probability of their getting addicted to the Internet got higher.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.385-394
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• 2017

In this study, reaction mechanism and curing characteristics of adhesives formulated with NaOH- and $H_2SO_4$-hydrolyzed chicken feather (CF) and formaldehyde-based crosslinkers were investigated by FT-IR and DSC. In addition, adhesive properties and formaldehyde emission of medium-density fiberboards (MDF) applied with the adhesives were measured. CF-based adhesives having a solid content of 40% and over were very viscous at $25^{\circ}C$, but the viscosity reduced to $300{\sim}660m{\cdot}Pa{\cdot}s$ at $50^{\circ}C$. Consequently, the adhesives could be used as a sprayable resin. Through the FT-IR spectra of liquid and cured CF-based adhesives, addition reaction of methylol group and condensation reaction between the functional groups with the use of formaldehyde-based crosslinkers were identified. From the analysis of DSC, it was elucidated for CF-based adhesives to require a higher pressing temperature or longer pressing time comparing to commercial urea-formaldehyde (C-UF) resin. MDF bonded with CF-based adhesives, which was formulated with 5% NaOH-hydrolyzed CF (CF-AK-5%) and PF of formaldehyde to phenol mole ratio of 2.5 (PF-2.5), and pressed for 8 min had higher MOR and IB than those with other CF-based adhesives. MOR and IB of MDF bonded with the CF-based adhesives regardless of formulation type and pressing time were higher than those with C-UF resin. When the values compared with the minimum requirements of KS standard, IB exceeded the KS standard in all formulations and pressing time, but MOR of only MDF bonded with CF-AK-5% and PF-2.5 and pressed for 8 min satisfied the KS standard. What was worse, 24-TS of MDF bonded with all CF-based adhesives did not satisfied the KS standard. However, MOR and 24-TS can be improved by increasing the target density of MDF or the amount of wax emulsion, which is added to improve the water resistance of MDF. Importantly, the use of CF-based adhesives decreased greatly the formaldehyde emission. Based on the results, we reached the conclusion that CF-based adhesives formulated under proper conditions had a potential as a sprayable resin for the production of wood panels.

• Journal of Life Science
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• v.31 no.8
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• pp.710-718
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• 2021

Placenta-derived mesenchymal stem cells (PD-MSCs) are promising candidates for cell-based therapy in regenerative medicine. The migration and homing potential of PD-MSCs to injured sites is a critical property of MSC engraftment. MicroRNAs (miRNAs) have recently been shown to regulate the critical functions of MSCs, such as proliferation, survival, and migration. The objective of the present study was to identify the miRNA and target genes involved in PD-MSCs homing in a bile duct ligation (BDL) rat model. We selected candidate miRNAs targeting genes for PD-MSCs homing based on microarray analysis. PD-MSC engraftment in BDL-injured rat liver was identified by immunofluorescence assay and human-specific Alu gene expression by quantitative real-time polymerase chain reaction (qRT-PCR) one week after transplantation. Compared with migrated naïve PD-MSCs under hypoxic and normoxic conditions (Hyp/Nor), the transplanted group with PD-MSCs (Tx) showed distinct differences in miRNA expressions in BDL-injured rat liver. We also validated the miRNAs and their target genes for PD-MSCs homing. The expressions of integrin α4 (ITGA4) and integrin α5 (ITGA5) target genes for miR-199a-5p and miR-148a-3p were significantly upregulated in the Tx group (p<0.05). In addition, integrin β1 (ITGB1) and integrin β8 (ITGB8) were upregulated by suppressing miR-183-5p and miR-145-5p, respectively. These results demonstrated that PD-MSCs regulate miRNA expression related to the integrin family for their homing effects on the BDL-injured rat liver. The findings further suggest that miRNA-mediated regulation of the integrin family contributes to the therapeutic efficacy of PD-MSCs in the rat hepatic fibrosis model by BDL.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.520-534
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• 2018

This study was conducted to understand the conceptual definition and characteristics of health inequality. To accomplish this, we analyzed data collected from 14 participants as well as from available literature regarding health inequality using the hybrid model introduced by Schwartz-Barcott and Kim. We categorized health inequality into nine attributes in three dimensions. These dimensions included "target", "precede", and "result," corresponding to the target, cause and consequence of health inequality, respectively. Specifically, we define health inequality as individuals, families, communities, socio-economic, or geographically distinct demographic groups that are treated unfairly and result in several problems such as loss of quality of life, reduction of survival rate, or aggravation of a disease due to (i) poor treatment by a hospital (ii) irregular meals, (iii) desperate need for work (for money), (iv) expensive medical care costs, (v) qualitative differences in medical care by regional groups (vi) the lack of knowledge regarding disease (vii) and inadequate health care because of lack of time. As a result of this unfair treatment, human rights violation occurs. The major contribution from this paper is that we provide a guideline for establishing strategies to reduce health inequality by identifying the concept of health inequality. Based on this study, we recommend development of an educational program to reduce health inequalities.

• Journal of Nutrition and Health
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• v.47 no.6
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• pp.475-483
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• 2014

Purpose: The purpose of this study was to measure accessibility and to examine distribution of restaurants in the local community. Methods: The target area of this study was two urban areas and a rural area in a city. We collected location information on all restaurants in target areas and classified all restaurants according to Korean food restaurants and Non-Korean food restaurants. We measured restaurant density per 100 m from the residences of the study population and calculated the distance of the nearest restaurant from the residences of the subjects using the Geographic Information System (GIS) analysis method. We compared the accessibility and distribution of restaurants in urban areas with that of the rural area, and compared the accessibility and distribution of Korean restaurants with that of Non-Korean restaurants. Results: Restaurants in urban areas were more dense than those in the rural area, and, in urban areas, restaurants were intensively distributed around the subjects' residence. Also, there were more Non-Korean food restaurants than Korean food restaurants in urban areas, and it was opposite in the rural area. Conclusion: It is important that we understood the current state of the restaurant environment in the local community using GIS analysis for the first time in the field of food environment. Further research is necessary on the association of restaurant environments and the dietary life of the population.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.682-691
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• 2005

We present a two-step evolution system that produces controllable virtual creatures in physically simulated 3D environment. Previous evolutionary methods for virtual creatures did not allow any user intervention during evolution process, because they generated a creature's shape, locomotion, and high-level behaviors such as target-following and obstacle avoidance simultaneously by one-time evolution process. In this work, we divide a single system into manageable two sub-systems, and this more likely allowsuser interaction. In the first stage, a body structure and low-level motor controllers of a creature for straight movement are generated by an evolutionary algorithm. Next, a high-level control to follow a given path is achieved by a neural network. The connection weights of the neural network are optimized by a genetic algorithm. The evolved controller could follow any given path fairly well. Moreover, users can choose or abort creatures according to their taste before the entire evolution process is finished. This paper also presents a new sinusoidal controller and a simplified hydrodynamics model for a capped-cylinder, which is the basic body primitive of a creature.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.10
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• pp.1559-1570
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• 2008

Since brought into from the economic life of nomads, the felt, the target of this study, has been developed in various ways of giving the functions of class symbol as well of protection against the cold and of ornamentation. Therefore, the study on how the felt was developed in Joseon Dynasty and how different culture from nomadic tribes it formed is significant in comprehensively under,;landing the economic, social and natural environmental factors in the Dynasty. The felt named "Jeon" has been constantly appearing in Korea from the ancient time, but it was not produced actively in the early part of Joseon Dynasty. That's why it was not a climatic condition suitable for sheep-breeding, and the government managed sheep-breeding but it aimed primarily at not producing clothing materials but having memorial ceremonies. Since sheep-breeding was not widely spreaded, production of Jeon was limited and some part was imported from China, so it was one of rare valuable goods. Therefore, the felt of wools named "Yangmojeon", the colored felt named "Chaejeon", etc. were used as liking items in the high-class society, and their materials and components were a little different depending on the official post. On the other hand, people in the low-class society used to wear the felt hats made of cattle feathers and miscellaneous fur, named "Jeonlip" and "Beougeoji". Since the middle of Joseon Dynasty, use of the felt was divided into two groups according to the users and the function, along with successful spreading of cotton and development of market economy. The function of Jeon to protect against the cold was replaced by cotton, but the felt hats of Beongeoji, Jeonlip, etc. were worn by common people continuously. As seen above, it is considered that the felt culture in Joseon Dynasty was formed very differently from the nomadic culture, because of its historical and sociocultural characteristics, and it had unique developing progress among all available fabrics.

• Journal of Korean Society of Disaster and Security
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• v.5 no.1
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• pp.43-47
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• 2012

The asset management of infra facilities is a total framework for finally supporting a safe and comfortable service, which includes functions of supporting evaluation of condition and performance of infrastructures, making the decision method of repair or rehabilitation of deteriorated facilities, and lengthening the life cycle of structure through the decision of adequate cost and time of repair or reinforcement. In the range of the asset management, organization, human, the target, and information & data of company are included. Therefore, in this paper, appling the method of asset management analysis to the infra structures, the process of the risk assesment using BRE (Business Risk Exposure) and the basis of consisting ORDM (Optimized Renewal Decision-Making) are expressed.