• 전기의세계
• /
• v.14 no.3
• /
• pp.28-33
• /
• 1965

This experiment is based on "the feasible improvement studies for an eliminating device of the static electricity which applies the ionizing effect of beta radiation." In order to accomplish this object, the following problems were necessarily considered to investigate and to determine. The efficiency of the elimination of static electricity was determined by means of measuring the ion current between electrically charged plates with micro-ammeter. The effects of various factors, i.e., the distance between charged plate and radiation source, the activity of radiation source, the electric otential and the area of the charged plate, the shape of the source housing, the lining of backscattering material (Pb) on the source housing surface and blowing of ionized air, on the static electricity eliminating efficiency were studied. The beta radiation sources used in this experiment were S$^{35}$ and Sr$^{90}$ -Y$^{90}$ . It was revealed that ion current increased with source activity, the electric potential and area of the plates, the lead (Pb) lining on the surface of the source housing and the velocity of the ionized air blowing. As one could expect the S$^{35}$ was more effective to increase the ion current since it is known to be a higher specific ionization source than Sr$^{90}$ -Y$^{90}$ . The detailed result and performance of the eliminating device of the static electricity are described here.ibed here.

• The korean journal of orthodontics
• /
• v.20 no.3 s.32
• /
• pp.593-608
• /
• 1990

Facial cleft is not a common anomaly of craniofacial region. But it is often accompanied with cleft lip and/or palate, so it seems important to orthodontist. Facial cleft is defined as a fissure or elongated opening of the facial region, and it's etiology is the failure of the fusion of the parts which will form the face in embryonic developmental period. Facial cleft can be classified according to the time of occurrence and the area involved during developmental period. It developes 1-2.5 weeks earlier than cleft lip and/or cleft palate. In facial cleft, the deformity is generally confined to the facial region, but sometimes deformity of other body region can accompany. The interaction of the facial cleft and the genetic anomaly is not confirmed, but genetic anomaly is known to be able to occur with the patient with other anomaly of body. As an orthodontist we should know the general considerations of facial cleft and it's treatment procedures other than orthodontic treatment.

• Korean Journal of Materials Research
• /
• v.14 no.2
• /
• pp.152-156
• /
• 2004

We have studied the effective optical absorption power of Si solar cell with $SiO_2$-antireflection layer based on a mathematical modelling of AM(air mass)1 spectrum and Si refractive index in the wavelength range(0.4 $\mu\textrm{m}\leq$λ$\leq$$0.97\mu\textrm{m}$). The effective optical absorption power obtained from the theoretical calculation was 450 and 520 W/$\m^2$ for the Si solar cells with $SiO_2$-antireflection layer of 500$\AA$ and 1000$\AA$, respectively. The optimum thickness of $SiO_2$-antireflection layer showing the minimum reflection loss was about 1000$\AA$ in the computer simulation. Two kinds of Si solar cells named EBS(500$\AA$) and EBS(l000$\AA$) were fabricated to evaluate the effect of $SiO_2$-antireflection layer thickness on the optical absorption. The epitaxial base Si cell with $SiO_2$-antireflection layer of 1000$\AA$ [EBS(l000$\AA$)] showed the output power improvement of about 15% upon the EBS(500$\AA$) cell due to larger absorption of effective optical power under illumination of AM1, 1 sun.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
• /
• 2005.09a
• /
• pp.83-88
• /
• 2005

유기 절연층을 갖는 유기 박막트랜지스터 (organic TFT)를 제작하여 소자 성능을 조사하였다. 유기 절연층의 형성에서는 polyvinyl 계열의 PVP(poly-4-vinylphenol)와 PVT(polyvinyltoluene)를 용질로, PGMEA (propylene glycol mononethyl ether acetate)를 용매로 사용하였다. 또한, 열경화성 수지인 poly(melamine-co-formaldehyde)를 경화제로 사용하여 유기 절연층의 cross-link 를 시도하였다. MIM 구조로 유기 절연층의 특정을 측정한 결과, PVT는 PVP에 비해 절연 특성이 떨어지는 경향을 보였다. 게이트 절연막의 제작에서 PVP를 cobpolymer 방식과 cross-linked 방식으로 실험 해 본 결과, cross-link 방식에서 낮은 누설전류 특성을 나타내었다. OTFT 제작에서는 PVP를 용질로, poly(melanine-co-formaldehyde)를 경화제로 사용한 cross-linked PVP 를 게이트 절연막으로 이용하였다. PVP copolymer($20\;wt\%$)에 $10\;wt\%$ poly(melamine- co-formaldehyde)를 혼합한 cross-linked PVP 를 게이트 절연막으로 사용하여 top contact 구조의 OTFT를 제작한 결과 약 $0.23\;cm^2/Vs$의 정공 이동도와 약 $0.4{\times}10^4$의 평균 전류점멸비를 나타내었다.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.854-859
• /
• 2009

Multiple people using places are being managed to prevent disasters by the special law for safety supervising of multiple people using spots. The KESCO is managing the places through intensification of inspection. Perfect safety is not insured by frequencyinspections because disaster symptoms in electrical facilities include invisible faults. Especially, entertainment spots, such as entertainment bars and karaoke bars, are different from other multiple people using places, and active reaction to prevent electrical fires is impossible. Therefore, special protection plans to prevent electrical disasters are needed. In this paper, equipments of entertainment spots were researched, and their electrical characteristics were analyzed. The function for detecting aloose terminal, which is one of the main causes of electrical fires, was developed.

• Proceedings of the KIEE Conference
• /
• 2005.11b
• /
• pp.58-60
• /
• 2005

This paper presents a optimal power flow calculation algorithm considering voltage and transient stability. In this method, voltage stability margin and transient stability constraints is incorporated into a optimal power flow calculation formulation to guarantee adequate voltage and transient security levels in power system. The proposed method is applied to IEEE-24 Reliability Test System and the results shows the effectiveness of the method.

• Proceedings of the KIEE Conference
• /
• 2009.04a
• /
• pp.172-173
• /
• 2009

최근의 가정용 전기 설비의 경우 다양화, 첨단화 되면서 과거에는 예상치 못했던 재해들이 발생하여 기존의 설비에 영향을 주는 경우가 생겨난다. 특히 누전 차단기의 경우 고조파, 대지 정전용량 등에 의하여 오동작 요소로 작용하고 있으며, 이를 해결하기 위한 방법으로 저항성 누설 전류에 대한 분석이 필요하며 이를 위하여 전압 위상과 전류 위상, 누설 전류 위상을 검출하여 비교함으로써 순수 저항성 누설 전류와 용량성 누설전류에 대한 분석을 검출 모니터링하여 비전문가 집단인 수용가 특히 가정에서 보다 안전한 전기사용과 관리에 활용 하고자한다.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.2086-2087
• /
• 2007

산업이 발달함에 따라 전기는 우리 일상 생활에 있어 없어서는 않 될 중요한 요소이나 그 사용에 따른 화재 위험성 또한 날로 증가하는 추세이다. 특히 전기 화재의 경우 전기는 시각적인 흐름을 볼 수가 없어 전기용품 사용에 있어 그 사고를 미리 감지하기 어려워 사고 위험성에 대하여 무방비 상태가 된다. 특히 우리나라의 경우 전체 화재 건수 중 전기 화재가 차지하는 비율은 30%이상으로 일본, 미국등 선진국에 비해 높아 화재원으로서 전기 화재예방에 대한 그 중요성 대두된다. 본 논문에서는 전기화재 발화 원인 중 단자대 접촉부 접촉 불량으로 야기된 과열에 의한 화재를 예방하기 위하여 접촉부 접촉 저항을 검출 하는 시스템에 대하여 알고리즘 개발 및 설계 하였다.

• Journal of the Institute of Convergence Signal Processing
• /
• v.16 no.2
• /
• pp.69-73
• /
• 2015

In this study, a method for estimating the amount of urination for men, was suggested and its performance was evaluated. This study is a preliminary one for the development of a health monitoring system that needs un-constraining, non-intrusive and long-term measurements in daily life. To estimate the amount of urination, a wide weighing plate with load cell was built and the difference in a man's weights between before and after urination was measured while he was standing on the plate. The results showed that the amount of urination can be estimated with the measured weight difference under the condition of mild movements. The largest measurement error of the suggested method was 40g, which means that this method can be applied to health monitoring in daily life. It is expected that the results of this study will be the basis for developing practical un-constraining and non-intrusive health monitoring system for daily use at home.

• The korean journal of orthodontics
• /
• v.30 no.1 s.78
• /
• pp.67-82
• /
• 2000

The purpose of this study was to present the causes and their mechanisms of eruption failure of teeth and to investigate the treatment modalities. There are so many reports about eruption failure, but most of them are dealing with local mechanical interferences. But, we have patients suffered from eruption failure of another causes. Many developmental failures show eruption problems of teeth, although in some cases, the primary failure of eruption (failure of the eruption mechanism itself) can be the primary cause. We have to know about the causes, differences, and the treatment modalities for those abnormalities.