• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2916-2921
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• 2008

This paper presents the performance and characteristics of small spark-ignited small 2-stroke engine. A single cylinder, two-stroke, air cooled 23cc SI engine for brush-cutter was used in this study. For the performance of the engine, rpm, torque, fuel consumption and lubricate oil consumption were measured, and also HC, CO, NOx emissions and excess air ratio according to throat open ratio under two lubrication method were measured and analyzed. The results showed that maximum of engine rpm is nearly same in both methods and also, torque, power is similar. exhaust emissions tend to decrease with throat open ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.153-156
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• 2000

To reduce the maintenance expense, and the possibility of electric outage and accident, we should optimize the outdoor insulation system. And for the optimization, accurate measurement for the degree of contamination with climatic conditions, such as wind, rain, and drought, should be carried. However the classical measuring method, brush wiping, has some problems in the aspect of man power, reliability, and expense. In this paper, we propose two type apparatus, which could detect the degree of contamination on insulators in outdoor insulation system, such as transmission and distribution line insulator and bushing. One use the leakage current, and the other use the oscillating frequency to check the degree of contamination. To avoid the oxidation of electrode AC source, and the low degree of contamination was applied. From the result of this investigation we could get the good relationship between the degree of contamination and the leakage current and oscillating frequency

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1063-1065
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• 1993

LDM, easy to minute position control, is using as X-Y plotter or other recording instruments. Brushless LDM has better properties than the conventional Brush type LDM in many aspects. This paper presents magnetic flux density distribution by FEM and a way to reduce thrust force ripple particurary in low speed drive. And we apply this method to a real mode of LDM. This LDM is operated by IBM-PC host computer and uses rotary encoder to make position signal.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1769-1770
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• 2007

To prevent an insulator failure, an automatic cleaning robot was developed for suspension insulator strings. The robot autonomously moves along the insulator string using the clamps installed on its two moving frames, and adopts a dry cleaning method using rotating brushes and a circular motion guide. In addition, a mechanized brush bristles and a voltage-balancing contactor are devised to increase cleaning efficiency and to prevent arc generation under live-line conditions, respectively. Moreover, a manual tool for its installation and removal is presented. We confirmed its effectiveness through experiments.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.94-98
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• 2006

The mattresses and dust in the bed rooms of nine dermatophytes infected patients and nine domestic animals were examined by the KOH method. Microsporum canis species and Trichophyton mentagrophytes were isolated from cats and rabbits, respectively. The sources of infection of three patients were the M. canis infected cats raised by them and the four other patient's sources of infection were not confirmed. The sites of infection of the nine patients were their heads and those of the domestic animals were their heads and bodies. M. canis species were isolated from the infection sites of three cats and specimens collected by hair brush from the nine domestic animals. T. mentagrophytes species were also isolated from the infection sites of two rabbits. The seven patients had mattresses and bed room dust contaminated with M. canis.

• Clinical Endoscopy
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• v.56 no.2
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• pp.164-168
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• 2023

When diagnosing the nature of biliary strictures, it is sometimes difficult to perform non-invasive methods such as ultrasound, spiral computed imaging, magnetic resonance imaging, or endoscopic ultrasonography. Thus, treatment decisions are usually based on biopsy results. However, brush cytology or biopsy, which is widely used for biliary stenosis, has limitations owing to its low sensitivity and negative predictive value for malignancy. Currently, the most accurate method is bile duct tissue biopsy under direct cholangioscopy. On the other hand, intraductal ultrasonography administered under the guidance of a guidewire has the advantages of easy administration and being less invasive, allowing for adequate examination of the biliary tract and surrounding organs. This review discusses the usefulness and drawbacks of intraductal ultrasonography for biliary strictures.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.159-165
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• 2015

A self-administered survey was conducted on the dental hygiene students at three different colleges located in Gyeonggi Province and South Chungcheong Province respectively from October, 2013, to the same month of 2014 to grasp their oral health management behavior, differences in plaque index according to plaque index systems and the correlation of the two. And their plaque index was measured. The findings of the study were as follows: 62.8% of the respondents replied they got a dental checkup over the past year, and 84.1% answered they received preventive dental treatment once at least or more. 80.5% replied they used a fluorine-containing dentifrice. 90.9% answered they used the rolling method to brush their teeth, and 50.0% replied it took three minutes to brush their teeth. They got a mean of 27.88 when O'leary index was used among plaque index systems. Their PHP index and PHP-M index were respectively a mean of 1.30 and a mean of 12.12. Their plaque index became lower when they spent more time brushing their teeth, and the toothbrushing time made a statistically significant difference to that (p<0.05). The factor that exerted the largest influence on plaque index was whether to brush teeth for the sake of oral health (B=-9.747, t=-3.752, p<0.001) or not. That made a statistically significant difference to it. The above-mentioned findings illustrated that more patients visited dental clinics than before to receive preventive dental treatment or to get dental checkups, and that toothbrushing time and whether to brush teeth for the sake of oral health or not were identified as the oral health management behaviors to affect plaque index.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.3
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• pp.113-122
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• 2019

Objectives: This study was conducted to investigate the snack intake and brushing behavior according to the oral health education experience in some schools in Busan, and to investigate whether the oral health education experience affects the snack intake and brushing behavior. Methods: This study surveyed the entire fourth grade of elementary school in two districts by participating in university-linked oral health education activities run under the jurisdiction of the education office business to examine changes in the behavior of elementary school students in their snack intake and toothbrush. The survey was conducted on oral health education in elementary schools, prior oral health education experience before and after the activity, whether or not the brushing classroom was operated, and contents related to eating snacks and brushing behaviors. Result: Among the general characteristics of some schools in Busan, 69.9% of students have experience in oral health education and 30.1% of people have no experience in oral health education. 20.0%, 16.3% were 'normal' and 63.7% were 'helpful'. The brushing behavior according to the oral health education was 44.9% in the number of brushings, 44.9% in the number of brushings, 45.7% in 2-3 minutes in the time of brushing, 41.2% in the brushing method by sweeping the brush up and down. In the daily brushing period, 'after breakfast' was the highest at 72.3%, and the parent's brushing instruction was 'to lead' at 65.1%. The amount of sugar in subjective snacks was the highest with 60.6% of sugar content, and the parents had the highest level of 52.2% for parents' snack intake. This result was more significant than the students without oral health education experience. Conclusion: Based on the results of this study, the number and time of brushing, the method and timing of brushing according to the experience of oral health education. Students who had oral health education experience higher than those who did not have oral health education, but had a lower tendency to brush after lunch at school and before going to bed. For better oral health, the effect of oral health education will be better if the school has more systematic toothbrushing at lunch time and parental guidance at home.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.275-283
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• 2016

The aim of this study was to evaluate the surface characteristics of composite resins polished with two different polishing methods. 30 disk-shaped specimens were prepared with microhybrid (Filtek$^{TM}$ Z250) and nanofilled (Filtek$^{TM}$ Z350) resins respectively, and classified into three groups: not polished as controls, polished by an abrasive disk (Soflex), and polished by a polishing brush (Occlubrush). Surface roughness was increased after polishing. In terms of micro-roughness, there were no significant differences between the two polishing methods. But macro-roughness values were markedly increased in the Occlubrush group (p < 0.05). In the Sof-lex group, the matrix and fillers were polished together, resulting into a smoother and homogeneous surface. However, in the Occlubrush group, the matrix layer was torn off, with more heterogeneous surfaces and large scratches. In regards to micro-hardness, no significant differences were observed between the two polishing systems (p > 0.05). And the hardness value increased about 25% after polishing. In conclusion, the method of polishing should be chosen deliberately in view of the hardness characteristics of composite resins. Sof-lex is recommended to improve the surface characteristics of polished resins.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.2
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• pp.139-146
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• 2016

Objectives: This study aimed to confirm the optimal processing conditions of the asbestos stabilizer by considering various actual environments at the time of stabilization treatment of the ceiling materials containing asbestos with asbestos stabilizer. Methods: The anti-scattering performances of the asbestos stabilizer were confirmed by considering the method and quantity of the asbestos stabilizer treated, comparing the loss weight by measuring the weight of ceiling materials prior to and after having treated 30, 50, 100, 200, and 400 of stabilizer using the brush and spray. The effects of backside dust and steel frame structure on the performances of the stabilizer was also confirmed by comparing samples with and without the dust on the rear surface removed by wiping the ceiling material specimens and the blinding treatment simulated by using tape. Results: The asbestos stabilization treatment using the brush method in comparison with the use of a spray has reduced stabilizer loss, resulting in better anti-scattering performance. In addition, the stabilizer loss is increased with increasing treatment quantity; as a result, treating a larger quantity of stabilizer does not improve the performance. For the conditions related to ceiling materials, the anti-scattering performance is enhanced by removing the backside dust and spreading the stabilizer evenly on the masking portion by steel frame structures. Conclusions: Based on these results, it is determined that the appropriate choice of the tool used for the treatment of the asbestos stabilizer and the appropriate quantity of asbestos stabilizer were needed at the time of actual stabilization processing of the ceiling materials containing asbestos. Moreover, this study confirmed that preliminary processing and verification of the structure at which the ceiling materials are installed can enhance the effectiveness of prevention of the scattering of asbestos into the air.