• Journal of Korean society of Dental Hygiene
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• v.12 no.6
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• pp.1221-1231
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• 2012

Objectives : The purpose of this study was to examine the oral health behavior and examine closely the connection factor and plans oral health promotion. Methods : This survey was conducted on 370 high school students in Kyunggi-do Suwon from November 21 to 23, 2011. 352 questionnaires were collected and analyzed. The collected data was analyzed using the statistical package SPSS WIN 15.0 using frequency, mean and standard deviation analysis, T-test, one-way ANOVA and Duncan's test correlation analysis. Results : The results state that 73.3% of students believe brushing teeth is very important and 26.7% of the students method of tooth brushing is up and down. for correct teeth brushing, they think choosing a brush is important(70.7%) also their brush shapes were uneven form(44.3%) and flat form(43.5%). 31.4% of students are using an oral hygiene device and 31.4% of students had received oral health education. 42.7% of female students get information about oral health from their dental clinics. 24.8% of male students receive information on oral health from parents and relatives. They think the best educator for oral health education will be a Dental hygienist(46.5%), or Dentist(48.0%). we found that a correlation between oral health interest, importance, knowledge and condition effect each other(p<.001). It means that if students have high oral health interest, oral care importance and oral health knowledge which can improve their oral health condition. Conclusions : The results of this study state that we need continuous oral health education systems and prevention programs to raise awareness among students and for the improvement of their oral health.

• Journal of Korean society of Dental Hygiene
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• v.13 no.6
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• pp.1005-1014
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• 2013

Objectives : The purpose of the study is to obtain the basic data for an industrial oral health project enhancing the quality of life and oral health. Methods : Questionnaire consisted of 17 questions including 7 questions of general characteristics, 5 questions of oral health awareness, and 5 questions of the behavior of oral health. A self-reported questionnaire was carried out from September 1 to September 28, 2012, The subjects were 400 male and female sanitation workers in private corporations in Jeonju. A total of 354 questionnaires were analyzed using SPSS windows ver. 12.0 (SPSS Inc. Korea). Results : The majority of the subjects were male in 50's. Temporary contract workers are older aged and 2 to 5 years of career workers were the majority of the cleaners. Average monthly income was less than 2 million Korean Won. Those who had a higher academic background and permanent position tended to have oral health knowledge (p<0.05). Female workers had healthier subjective oral health status than male workers. Those who were in older age, single, temporary position, and 2 to 5 years of career tended to have healthier subjective oral health status (p<0.05). Those who were in older age, married, and long period of employment were worrying about their health (p<0.05). The subjective oral health knowledge was high in 49.7% of the workers because they were not able to brush teeth during work hours. They were able to brush their teeth only after dinner. It was low in female and older aged workers (p<0.05). The brushing method included a combination of top to bottom and from the side to side. Conclusions : This study showed the influencing factor of oral health in street workers. Work environment, education, age, monthly income, and types of employment were the important factors to oral health care. It is necessary to provide the right oral health care program for the workers in the near future.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.895-902
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• 2014

Objectives: The purpose of the study was to investigate the actual oral health status and dental fear level in the elderly. Methods: Data were collected by questionnaire interview method from June 15, 2013 to December 14, 2013. The subjects were elderly over 65 years old in Jeonbuk province. The study instrument was structured questionnaire including general characteristics of the subjects(3 questions), oral health management status(16 questions), Dental Fear Survey(DFS, 9 questions). Cronbach alphas were 0.804 and 0.959 in the study. Higher score of oral health management status showed good oral health care and higher DFS showed higher level of dental fear. Data were analyzed by t-test, one way ANOVA, post-hoc Scheffe test, and Pearson correlation analysis. Higher dental fear was defined below 33.3%. Results: Women tended to have better oral health than male. Women brush their teeth more frequently than male. Most of the elderly answered that it was important to brush teeth for 3 minutes, to use dental floss and to have oral health education(p<0.05). Score of dental fear level was similar in men and women. Those who were above 69 years old tended to have dental fear. Poor oral health condition was closely related to dental fear. Conclusions: The oral care in the elderly showed considerable differences between the groups and affected the dental fear. It is important to implement the nationwide dental care for the elderly in the future.

• Journal of the Korean Society of School Health
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• v.27 no.1
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• pp.1-6
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• 2014

Purpose: The purpose of this study was to investigate the effect of oral health education on adolescents. Methods: The subjects were middle school students in a health promoting school in Gunpo, Gyeonggi Province. Before giving the students oral health instruction, their modified Patient Hygiene Performance index (PHP index) was measured using disclosing solution. Then, the students were taught the right way to brush teeth (Rolling method) and use oral hygiene devices such as dental floss, tongue cleaner and interdental brush. Their modified PHP index was re-measured three days after and seven days after the education to evaluate the effect and persistency of oral health education. of the total 116 students, 48 students who completely filled out the questionnaire and participated in the whole process, photo shooting and three times of PHP index measurement, were included in the final analysis. Results: The students' modified PHP index significantly decreased three days after the education. However, the index slightly went back up seven days after the oral health education. Conclusion: Oral health education was effective in reducing dental plaque which remained after brushing. Continuous education about and constant motivation for oral hygiene turned out to be critical to maintain the impact of oral health education. Therefore, it is necessary to develop educational contents which can constantly motivate teenagers.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.259-267
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• 2021

Peri-implantitis, in which inflammation caused by plaque and biofilm on the implant surface spreads to the hard tissue, can be treated by decontamination of the implant surface and reconstruction of the lost hard tissue through surgical methods. We have described the management of 3 peri-implantitis cases by decontamination of the implant surface using a round titanium brush and regenerative therapy. All cases showed clinical improvements, and no further radiographic bone loss was observed during a 2-year follow-up. This treatment method can be effective for clinical improvement and bone regeneration. However, a longer follow-up period is necessary to support these outcomes.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.2
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• pp.57-62
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• 2018

A brush-less type synchronous generator driven by an internal-combustion engine is used for emergency electric source. These types of generators have to maintain a certain range of output voltage even under the sudden load change conditions such as full load application and removal. This paper describes a method for suppressing the output voltage of a synchronous generator that operates excessively when the load fluctuates. The method used in this paper is a feedforward control method in which the main voltage control consists of a feedback loop using a typical PID controller and the load current is detected as a disturbance element and compensated directly. A feedforward system is constructed in which the load current is regarded as disturbance, and the appropriate feedforward controller configuration and parameters are found through simulation. Finally, it can be seen through the experiment that the feedforward control is performed properly. It can be seen that the generator terminal voltage is recovered to the steady state in a short period of time as compared with the existing PID control method even when the entire load of the generator is changed.

• Design & Manufacturing
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• v.11 no.2
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• pp.20-24
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• 2017

Recent industrial developments are constantly advancing, and rapid technological development is demanding high technology level in related fields. The need for polishing is increasing even more to improve quality. In order to improve the surface quality, the final finishing process or polishing process is a very important part. Research on super precise polishing method using MR fluid is actively being carried out in domestic and foreign countries. Fine magnetic abrasive grains are aligned in the direction of a magnetic force line formed by a magnetic field and serve as a brush to polish a metal surface. This method has the advantage that the shape of the tool is not fixed and is not affected by the shape of the workpiece or the machining area. We will design the electromagnets for the MR polish polishing system and apply the magnetic field analysis using the magnetic field analysis program (ANSYS). The data obtained through this process suggests an efficient method to increase the magnetic flux density important for polishing. We will investigate the influence of the Al6061-T6 specimen on the surface of the MR polishing machine based on the optimized design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1895-1898
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• 2017

This paper discusses methods for the torque ripple and noise reduction of DC motors for automotive air-conditioning based on electromagnetic field analysis. The target of the motor is a blower motor, and to reduce cogging torque and the torque ripple, the optimum model was selected by deforming the brush or commutator shape. In addition, to reduce the cogging torque, the model design was carried out by applying the skew method and the magnetization method of a magnet to the rotor. For optimization, the shape, material, and drive system of the motor were selected using an electromagnetic field as the analysis tool, and the method of reducing the cogging torque was applied to 4-pole, 12- and 13-slot motors considering the mechanical part. Lastly, this paper confirmed thatthemethod, which proposed how much noise, cogging torque, and vibration are reduced, improves through practical analysis.

• Cartoon and Animation Studies
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• s.37
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• pp.143-158
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• 2014

In the modeling processes of 3D computer animation, methods to build optimal work conditions to realize real forms for more efficient works have been advanced. Digital sculpting software, published in 1999, ZBrush has been positioned as an essential factor in character model work requiring of realistic descriptions through different manufacturing methods from previous modeling work processes and easy shape realization. Their functional areas are expanding. So, in this production case paper, as a method to product more optimized animation character models, the efficiency of production method linking digital sculpting software (Z-Brush) and animation production software (Maya) was deliberated and its consequences and implications are suggested. To this end, first the technical features of polygon modeling and Retopology were reviewed. Second, based on it, the efficiency of animation character modeling work processes through step linking ZBrush and Maya suggested in this paper was analyzed. Third, based on the features drawn before, in order to prove the hypothesis on modeling optimization method suggested in this paper, the production process of character Dumvee from a short animation film, 'Cula & Mina' was analyzed as an example. Through this study, it was found that technical approach easiness and high level of completion could be realized through two software linked work processes. This study is considered to be a reference for optimizing production process of related industries or modeling-related classes by deliberating different modeling process linked systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.603-608
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• 2018

Although the voltage-applied discharge method is most widely used in the semiconductor and display industries, periodic management costs are incurred because the method causes defects due to the absorption of ambient fine dust and causes emitter tip contamination due to the discharge. The emitter tip contamination problem is caused by the accumulation of fine particles in ambient air due to the corona discharge of the ionizer. Fuzzy ball generation accelerates the wear of the emitter tip and deteriorates the performance of the ionizer. Although a mechanical cleaning method using a manual brush or an automatic brush is effective for contaminant removal, it requires management of additional mechanical parts by the user. In some cases, contaminants accumulated in the emitter may be transferred to the wafer or product. In order to solve this problem, we developed an ionizer for a clean environment that can remove the pencil-type emitter tip and directly ionize the surrounding gas molecules using the tungsten wire located inside the ion tank. As a result of testing and certification by the Korea Institute of Machinery and Materials, the average concentration was $0.7572particles/ft^3$, the decay time was less than two seconds, and the ion valance was 7.6 V, which is satisfactory.