• 한국안전학회지
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• 제25권2호
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• pp.7-11
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• 2010

Difficulties associated with full-scale pipe tests are rather obvious. That is, it is not only difficult to perform them but also very expensive and it requires lots of experience. And the process of the fracture test for the pipe specimen is very difficult and complicated. Because the pipe specimen, the test jig and the test equipment are very large and heavy, it requires lots of costs and times. In this study, to easily perform the fracture toughness test for a pipe specimen, load line displacement data was obtained using the image processing method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1834-1836
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• 2003

In this paper, a superposed discharge type ozonizer(SDO) has been designed and manufactured. SDO is equipped with three electrodes(central, internal and external electrodes), and it is composed of two gaps. Ozone is generated by overlapping silent discharge, which is respectively came from two gaps. At this time, Internal electrode consists of a mesh type. This paper describes the discharge and ozone generation characteristics of SDO with variation of mesh and discharge wattage.

• 대한물리치료과학회지
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• 제1권2호
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• pp.345-353
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• 1994

Shoulder pain is probably the most frequent complication of hemiplegia. Many of the factors contributing to the occurrence of shoulder pain in hemiplegia have shown that the lesions of the rotator cuff tendon or the tendon of the long head of the biceps brachii, the reflex sympathetic dystrophy syndrome, shoulder-hand syndrome, subluxation and rupture of the rotator cuff. Subluxation has been measured by finger breadths, X-Ray, Radiological measure and jig device. The propose of this study decribes the sourse of shoulder pain with hemiplegia, method for subluxation measure and treatment of. hemiplegic shoulder pain.

• 한국주조공학회지
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• 제25권6호
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• pp.249-253
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• 2005

The present study focuses on 7075 aluminum wrought alloy to investigate the potential industrial applications of thixoextrusion process. The microstructural evolution of 7075 aluminum wrought alloy for thixoextrusion has been investigated as a function of isothermal holding temperature and time in the partially remelted semisolid state. The results showed that the liquid fraction increased with increasing isothermal holding temperature and time while the average grain size was inversely proportional to isothermal holding temperature and time up to 5min. However, there was no big change of liquid fraction and average grain size with respect to isothermal holding temperature and time. The important fact that the liquid fraction and average grain size were almost uniform after 5 min holding time is considered very useful for thixoextrusion in terms of process control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.347-348
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• 2007

최근 한반도 및 그 주변에 중소규모 이상의 지진이 빈번히 발생하고 있으나, 국내 대부분의 변전설비들은 내진설계개념을 적용하지 못하고 있는 실정이다. 특히 765kV 변전설비는 산업적, 경제적으로 중요한 국가설비이므로 전력공급 중단을 막기 위해 내진성능확보가 필수적이다. 따라서, 본 연구에서는 765kV 변전소 내 대표설비인 가스절연 개폐장치를 대상으로 내진성능평가를 수행하였으며, 그 결과 지진에 일부 취약한 부위가 발견되어 내진성능개선을 위한 보강이 필요한 것으로 나타났다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.439-440
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• 2014

본 논문에서는 발생전압이 충전전압보다 높은 경우는 Buck 컨버터로 동작하고 발생전압이 충전전압보다 낮은 경우 Boost 컨버터로 동작하는 모드 자체를 독립적으로 구현할 수 있는 새로운 형태의 DC-DC 컨버터를 제안함으로서 시비율 변화를 줄여 인덕터의 전류 리플을 줄임으로서 효율을 개선하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.563-565
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• 1993

This paper describes ozone concentration and discharge characteristics in flowing $O_2$ with variation of Re at high voltage nozzle(HVN). HVN type ozonizer is equipped with ten nozzle. The important conclusions obtained from this paper are as follows. For constant pulse width(Pw) and pulse frequency(Pf) the more Re increases, the higher corona onset voltage(Vc) rise. Vc is inversely proportional to Pw and Pf. Ozone concentration($O_{3con}$) increases with less Re for constant Pw and Pf. $O_{3con}$ increases with less Pw. $O_{3con}$ is proportional to Pf.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.156-163
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• 1998

During an actual forming operation, a material may undergo considrably large changes in strain path, and these changes can significantly alter the forming limits. So, in this study, modified forming limit curves(FLCs) in complex strain path are determined with specially designed jig to give test specimens with desired prestrains in uniaxial or biaxial deformation mode. In another part of present study, theoretical prediction of FLCs is attempted with MK's theory and Hosford's yield criterion to give forming limit curves in positive minor strain region and with Hill's local necking theory in negative minor strain region. Comparison of these theoretical results with experimental ones will be mentioned for both linear and complex strain path.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.87-91
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• 2013

Rubber Components have been playing important role for the isolation of noise and vibration of vehicle. This paper is presented the new method of dynamic modeling of rubber component for simulating the dynamic characteristics of it under the varing loading condition. Rubber dynamic model consists of the hyperelastic, viscoelastic and elasto-plastic characteristics of rubber. Dynamic proporties of rubber are calculated at each preload and frequency conditions, compared to test data, and evaluated the validity of rubber dynamic model. This technique is expected to understand and improve the characteristics of noise and vibration with relation to rubber components.

• 한국정밀공학회지
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• 제21권7호
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• pp.171-178
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• 2004

Techniques and procedures are presented for measuring mechanical properties on thin-film Polysilicon. Narrow platinum lines are deposited 250 ${\mu}{\textrm}{m}$ apart on tensile specimens that are 3.5 ${\mu}{\textrm}{m}$ thick and 600 ${\mu}{\textrm}{m}$ wide. Load is applied by a piezo-actuator and by hanging weights. Strain is measured by an ISDC at temperatures up to 500 $^{\circ}C$. Measurements of the elastic modulus with jig modifications, loading speed and temperature change are presented first. And then, the preliminary data for the coefficient of thermal expansion and creep behavior are presented as a reference.