• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.1
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• pp.10-18
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• 2000

This paper proposes a fuzzy logic cross-coupled controller using a new contouring modeling for a two-axis servo system. The general decoupled control approach may result in degraded contouring performance due to such factors as mismatch of axial dynamics and axial loop gains. In practice, such systems contain many uncertainties. The cross-coupled controller utilizes all axis position error information simultaneously to produce accurate contours. However, the conventional cross-coupled controllers cannot overcome friction, backlash, and parameter variations. Also since, it is difficult to obtain an accurate mathematical model of multi-axis system, here we investigate a fuzzy logic cross-coupled controller of servo system. In addition, new contouring error vector computation method is presented. The experimental results are presented to illustrate the performance of the proposed algorithm.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.245-256
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• 1989

Translational movement along an arch wire requires sufficient force to overcome frictional forces between bracket and arch wire. The orthodontist must appreciate the importance of friction in this process, and study out the influencing factors on the level of friction. The purpose of this study was to evaluate the effect of artificial saliva on frictional resistances generated between the bracket and arch wire. Independent variables of this study were arch wire material, angulation and environment. Static frictional forces of cobalt-chromium, heat-treated cobalt-chromium, beta-titanium, stainless steel wires were measured under non-angulated dry, angulated dry, non-angulated saliva, angulated saliva conditions. The results were as follows: 1. Stainless steel wires showed lower friction values in non-angulated dry condition, and heat-treated cobalt-chromium wires showed higher friction values in angulated dry condition. Higher friction values were showed in order of cobalt-chromium. stainless steel, heat-treated cobalt-chromium and beta-titanium wires in non-angulated saliva condition. and were showed in order of stainless steel, cobalt-chromium, heat-treated cobalt-chromium, beta-titanium wires in angulated saliva condition. 2. Angulation increased friction for stainless steel wires under dry condition. 3. Artificial saliva decreased friction for cobalt-chromium wires and increased friction for stainless steel wires under non-angulated condition. 4. Artificial saliva decreased friction for all wires except beta-titanium wires under angulated condition. 5. Regardless of angulation or environment. heat-treated cobalt-chromium and beta-titanium wires showed higher friction values, and stainless steel wires showed lower friction values.

• Korean Journal of Social Welfare
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• v.64 no.2
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• pp.299-323
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• 2012

The purpose of this study is to understand social exclusion experiences with the disabled through a biographical study. It is analysed the interview date conducting an interview about 10 focused on the physical and cerebral palsy disabled with social exclusion experiences. The results show that it is multi-social exclusion including the inequality of approach opportunity of education, labor, education, medical, social participation, information, social service, space, health etc. It shows their life neglected and marginalized resulted from not providing social right as citizenship. And their social relationship is isolated by social exclusion and Other-directed identity is to be shaped in accordance to the method to define as regulated social ideals. Also, there is their painful and heavy life bound with double risky factors of disability and poverty. They share common historical experiences and social events impacted on their recognition and value among participants generation in biographical narrative. On the other hand, their life is reconstructed according to each their resource and standard to interpreter and evaluate on it. It suggests political and clinical implications in order to overcome the disabled's social exclusion, which is based on practical and vivid experiential dates from the participants.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.6
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• pp.361-367
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• 2019

Background: Although studies on dental fear in relation to sex and age have been conducted, there have been few nationwide studies particularly on the youth sector. In addition, no validity and reliability verifications have been implemented for new research groups on the Korean version of the Dental Fear Survey (K-DFS). Therefore, this study aimed to apply the K-DFS developed in a previous study on Korean youth to draw conclusions on dental fear among the youth. Methods: This study used the K-DFS, a Korean translation of Kleinknecht's Dental Fear Survey for elementary school, middle school, and high school students. This study selected 2,161 young people of various ages as participants and increased the validity of the research results by expanding nationwide the scope of the study area. Results: Differences in fear levels according to sex were higher in boys fear behavior scores than in girls' regarding dental treatment (P < 0.05). Students with dental fear had higher scores on items associated with dental treatment and fear of dental stimuli compared with students without dental fear (P < 0.05). Differences were observed among the three groups (P < 0.05). However, the results of logistic regression analysis showed no statistically significant differences for dental visits based on sex, grade, and other subcomponents (P > 0.05). Conclusion: By verifying the validity of the newly developed K-DFS, this research confirmed its utility as a dental fear questionnaire. Therefore, there can be no objection that the grounds for criticism have been established according to conventional wisdom. In the future, however, developing and studying the limits of K-DFS that overcome the factors of dental fear, especially pain, will help reduce dental fear in adolescents.

• The Korean Journal of Community Living Science
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• v.15 no.3
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• pp.121-135
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• 2004

'Long-life' which has been the perennial interest to human beings also carries the risk of multiple losses such as the death of the family members and friends, the loss of physical and cognitive functions. In that regards, living a long life to be the 'oldest-old' could mean not only a 'symbol of successful aging' but also a hardship and low quality of life at the same time. Therefore, the issue of the quality of life of the oldest old has been the subject of the much of the public and research concern in recent days. While there has been increased awareness about the importance of the subjective aspects of the quality of life and meanings attached to the extended life, most researches on the quality of life of the oldest-old have focused only on the objective conditions of the quality of life such as health, economic status and housing conditions. To overcome these limitations this study aims to explore the subject meaning of 'living a long life' in Korean society by investigating centenarians and their caregivers' interpretations of aging experiences. Qualitative data were gathered from the forty-nine Korean centenarians and their caregivers through in-depth interview. Each interview was tape-recorded and transcribed verbatim. Researchers read each transcript a number of times to get some emerging themes. Most striking result was the fact that most of the centenarians express the 'guilty feelings' and try to offer the 'excuses' about their long life. This results were quite contrary to the results of the studies, done in Japan and western countries like Sweden, United States and Germany, where most of the oldest-old express quite positive interpretations about their long-life and take pride in their longevity. Lack of social support, cohort characteristics of the Korean oldest-old and the cultural interpretations linking the death of children to the long life of older generation are given as possible factors to these unique findings of Korean study. The policy implications of the results are discussed.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.105-113
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• 2018

The modeling of noise mapping and the evaluation of noise pollution based on the exposed population were frequently used as an indicator of environmental noise assessment to overcome the limitations of field survey and Tele-Monitoring System. Results from these methods were highly influenced by the setting of noise source, input data of prediction factors and analytical methods of predictive values. The population exposed to noise were estimated as M1-1>M2-1>Base>M2-2>M1-2 in both areas. The highest noise setting methods(M1-1, M1-2) were overestimated, being compared with the Base method.

• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.61-66
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• 2008

More than 70% of Korea consists of mountainous area and during the construction of roads and railroads many cut-slopes are inevitably formed. A number of environmental factors, such as the rainy season and frost heave during winter/thaw during spring, can result in rock falls and landslides. The failure of slopes is increasing every year and can cause damage to vehicles, personal injury and even fatality. In order to help protect people and property, there is a need for real-time monitoring systems to detect the early stages of slope failures. In this respect, the GMG has been using Translation Rotation Settlement (TRS) sensor units installed on slopes to monitor movement in real-time. However, the data lines of this system are vulnerable and the whole system can be damaged by a single lightning strike. In order to overcome this, GMG have proposed the use of Ubiquitous Sensor Networks (USN). The adoption of a USN system in lieu of data cables can help to minimize the risk of lightning damage and improve the reliability of slope monitoring systems.

• Health Policy and Management
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• v.27 no.4
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• pp.284-295
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• 2017

Background: The objectives of this study were to identify the reasons of quitting smoking, to determine the factors that make it difficult or helpful to maintain smoking cessation and to confirm the changes after the smoking cessation. Methods: This study was conducted an in-depth interview with people who participated in the smoking cessation treatment program. There were 10 participants and they were interviewed thoroughly for 14 times. Using the directed content analysis, we analyzed the transcript which was written by recording the interview and the researchers' note. Results: The results of this study are summarized as 'the experience while at the verge of smoking cessation and stepping over the verge of smoking cessation,' 'the changing experience due to smoking cessation,' and 'maintaining the changes through overcoming re-smoking.' The smoking cessation treatment program induced the smokers to quit smoking. Participants mentioned drinking alcohol was the major obstacle to maintain smoking cessation. Also, they noted that the money and the time that were already spent to quit smoking helped their smoking cessation as well as the social relations which helped to prevent re-smoking. Participants felt well-cared through the smoking cessation treatment program and that it helped them to maintain smoking cessation. Conclusion: Smoking cessation treatment program has a positive effect on the smoking cessation trial and maintenance. In order for smokers to overcome re-smoking, educations regarding drinking problem, formation of supportive social relationship, and the applications for smoking cessation will be beneficial.

• Molecules and Cells
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• v.41 no.4
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• pp.362-372
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• 2018

High mobility group box 2 (HMGB2) is an abundant, chromatin-associated, non-histone protein involved in transcription, chromatin remodeling, and recombination. Recently, the HMGB2 gene was found to be significantly downregulated during senescence and shown to regulate the expression of senescent-associated secretory proteins. Here, we demonstrate that HMGB2 transcription is repressed by p21 during radiation-induced senescence through the ATM-p53-p21 DNA damage signaling cascade. The loss of p21 abolished the downregulation of HMGB2 caused by ionizing radiation, and the conditional induction of p21 was sufficient to repress the transcription of HMGB2. We also showed that the p21 protein binds to the HMGB2 promoter region, leading to sequestration of RNA polymerase and transcription factors E2F1, Sp1, and p300. In contrast, NF-Y, a CCAAT box-binding protein complex, is required for the expression of HMGB2, but NF-Y binding to the HMGB2 promoter was unaffected by either radiation or p21 induction. A proximity ligation assay results confirmed that the chromosome binding of E2F1 and Sp1 was inhibited by p21 induction. As HMGB2 have been shown to regulate premature senescence by IR, targeting the p21-mediated repression of HMGB2 could be a strategy to overcome the detrimental effects of radiation-induced senescence.

• Information Systems Review
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• v.7 no.2
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• pp.163-181
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• 2005

In this paper, we report case analysis on entob.com which is one of the leading domestic players in MRO e-marketplace. Critical success factors of achieving early liquidity and right ownerships are addressed for successful e-marketplace launching. Change management issues, required to encourage suppliers participation and to overcome adoption barriers from buyer firms, are suggested and illustrated for the successful implementation of the MRO e-marketplace. The business model architectures enabling to create e-intermediary value to both the suppliers and buyers are detailed. Finally, benefits of buyer firms captured through e-procurement business process streamlining and material cost savings are reported as the successful application stories. The findings suggest practical managerial insights for MRO e-marketplace implementation and further research.