• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.501-503
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• 2000

Since an arrester has been generally used at the distribution line and abroad for the protection of electrical equipments against overvoltage (or abnormal surge) taking place in or from an electrical system, a fault, especially, in the distribution line is very likely to result in the destruction of insulation of other protection devices to cause an overall paralysis of a power system, a chaos. Considering the importance of arresters, its earlier replacement than its proposed life cycle causes an economical loss, and a negligence not to replace or repair it in time gives rise to a crucial accidence. The purpose of this paper is to invent an electric leakage current detector and to solve such problems by the continuous and regular inspection of an arrester.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권4호
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• pp.318-325
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• 2002

The primary method of diagnosis in craniofacial deformity patient is used by gross inspection. So we studied the frontal photometric measurements for maxillofacial Korean normals 44 male and 48 female ages 19 to 20 years were selected from a group of 92 healthy Kyung Hee university students in Seoul.. The photograph were taken with the subject sitting in head position parallel with interpapillary plane to the floor. During taking pictures, facial anallyser by Obwegeser(Martin Co., Germany) was used for correct measurements. The results of this study was followed. 1. In the linear measurements, all values of males were longer than those of females but middle third height and lower third height, facial width and nasal width of males were longer than those of females in p<0.05 2. The difference between right and left angular and linear measurement was insignificant. 3. In the horizontal facial ratios, interocular distance and nasal width were longer and mouth width were smaller in korean than in american(p<0.05). 4. In the vertical ratios, korean women have shorter facial height of lower third comparing with facial height of middle third than american(p<0.05). 5. In the vertical facial ratios, korean have smaller proportion below the stomion in the lower third department than american. (p<0.05).

• Journal of Platform Technology
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• 제11권2호
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• pp.54-65
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• 2023

전기자동차에 사용되는 배터리는 전기자동차의 특성상 정격용량이 매우 커다란 배터리이다. 전기자동차를 장기간 운행하거나 교통사고로 전기자동차가 폐차되게 되면 전기자동차용 배터리는 폐배터리가 된다. 폐차되는 차량이더라도 전기자동차용 폐배터리에 남아 있는 용량은 다른 용도로 사용하기에 충분하다. 자동차용 폐배터리는 매우 고가이기때문에 재활용 및 재사용이 필요하지만 재활용 및 재사용을 위한 폐배터리 성능등급 측정기준이 부족한 문제가 있었다. 폐배터리의 잔존용량을 측정하는 방법으로 가장 안정적이고 신뢰할 수 있는 방법은 완전 충·방전을 이용하여 배터리의 잔존용량을 측정하는 것이다. 하지만 이러한 완전 충·방전에 방식에 의한 검사 방법은 배터리의 용량에 따라 다르지만 검사하는데 하루 이상이 걸리는 단점을 가지고 있으며 많은 사람들이 이러한 문제를 해결하기 위하여 많은 노력을 하고 있다. 본 논문에서는 전기자동차 배터리에 대한 검사 시간을 줄일 수 있는 방법으로 셀간 전압 편차를 활용한 전기자동차 배터리 잔존용량 분석 기법을 연구 분석하였다. 이를 위하여 완전 충·방전 기반의 용량 측정시스템을 구성하고 코나 폐배터리를 이용하여 실험데이터를 수집하였고 배터리 팩을 구성하고 있는 배터리 셀간 전압 편차와 잔존용량과의 상관관계를 분석하여 배터리 검사에 활용할 수 있는지를 검증하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권2호
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• pp.115-123
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• 2001

The primary method of diagnosis in craniofacial deformity patient is used by gross inspection. The study for objective analysis and evaluation in Korean maxillofacial soft tissue portions is rare and our normals have been based on Caucasian such as American. But it is difficult to apply it to ours so we studied the frontal photometric measurements for maxillofacial Korean normals. The photograph were taken with the subject sitting in head position parallel with interpupillary plane to the floor. During taking pictures, facial analyser by Obwegeser in Martin was used for correct measurements. 54 male and 57 female ages 14 to 15 years were selected from a group of 111 healthy middle school students in Inchon. 1. The vertical measurements in glabella-subnasale, subnasale-stomion and stomion-menton in the male were higher than in the female subjects in $14{\sim}15$ years old Korean, so middle and lower third face were higher than those of female(p<0.05). 2. The horizontal measurements of female was higher than those of male in the rt. and It. eye width but smaller in nose width and lip width(p<0.05). 3. There was no significant difference in gender compared with soft cheek and mention angle measurements When our reports were compared with american white population, the vertical proportions in Korean normals were similar to american and the line measurements in middle facial length, nose width and intercanthal distance were higher than those of american.

• 한국정밀공학회지
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• 제22권12호
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• pp.51-60
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• 2005

This paper describes a robust control scheme for high-speed and long stroke scanning motion of high precision linear motor system consisting of linear motor, air bearing guide and position measurement system using heterodyne interferometer. Nowadays, semiconductor process and inspection of wafer or LCD need high speed and long travel length for their high throughput and extremely small velocity fluctuations or tracking errors. In order to satisfy these conditions, linear motor system are widely used because they have large thrust force and do not need motion conversion mechanisms such as ball screw, rack & pinion or capstan with which the system are burdened. However linear motors have a problem called force ripple. Force ripple deteriorates the tracking performances and makes periodic position errors. So, force ripple must be compensated. To maximize the tracking performance of linear motor system, we propose the control scheme which is composed of a robust control method, Time Delay Controller (TDC) and a feedforward control method, Zero Phase Error Tracking Control (ZPETC) for accurate tracking a given trajectory and an adaptive force ripple compensation (AFC) algorithm fur estimating and compensating force ripple. The adaptive ripple compensation is continuously refined on the basis of tracking error. Computer simulation results based on modeled parameters verify the effectiveness of the proposed control scheme for high-speed, long stroke and high precision scanning motion and show that the proposed control scheme can achieve a sup error tracking performance in comparison to conventional TDC control.

• 한국치위생학회지
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• 제9권4호
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• pp.670-684
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• 2009

Objectives : This research analyzed the general characteristics that closely affect the children's dental health and the mothers' dental health knowledge and dental health behavior to identify the correlation of the latter with the status of children's dental health in order to provide the basic data for the development of dental health business that would target children. Methods : Research subjects were selected arbitrarily from three nursery schools located in Busan metropolitan city, targeting 186 children between the ages of four to six and their mothers. The children were subjected to dental Inspection, and the status of their dental caries was studied whereas the mothers were subjected to the surveys on the general characteristics, dental health knowledge and dental health behavior. Results : 1. Level of mothers' dental health knowledge is higher when the mothers' educational level is higher(p=0.02) and when the household's monthly income is higher(p=0.009). 2. When the level of mothers' dental health knowledge is higher, children tended to brush their toothbrushing using proper method(p=0.025). Moreover, when the level of mothers' dental health knowledge is higher, they tended to take their children to dental clinic mostly for preventive measures than for treating cavity(p=0.023). 3. When the level of mothers' dental health knowledge is higher, children's dmft index was significantly low(p=0.02). When the mothers use fluoride-containing toothpaste, children's children' dmft index was even lower(p=0.02). 4. As the children tended to brush their teeth more often, dmft index was lower(p=0.003). When the reason that the children visited dental clinic was more to prevent, than to treat cavity, dmft index was even lower(p=0.000) Conclusions : When the above mentioned results are summarized, it is possible to know that the mothers' dental health knowledge and dental health behavior significantly affect children's dental health. Accordingly, it is necessary to develop maternal and child dental health program that factors in both the mothers and children in order to prevent children's dental caries and to increase their dental health, and continued care is required to discover and treat dental caries early on.