• Journal of the Korean Wood Science and Technology
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• 제36권4호
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• pp.26-36
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• 2008

건축구조 설계기준이 개정됨에 따라서 목조건축물의 제한 기준이 완화되어 경골 목조건축의 다층 시공이 가능하게 되었다. 건축물의 규모 증가는 건물에 작용하는 하중을 증가시키므로 증가된 작용하중에 맞추어 하중저항성능을 향상시켜 설계하고 시공해야 한다. 기존에는 경골 목조건축의 전단성능을 향상시키기 위하여 벽량을 보강하는 방법을 적용하였으나 본 연구에서는 홀드다운 접합철물을 사용하는 방법을 적용하였다. 홀드다운은 아직까지 국내에서 보편적이지 않은 접합철물이므로 홀드다운의 국내 적용 적합성을 평가하기 위하여 본 연구를 수행하였다. 홀드다운을 적용한 경골 목조 전단벽에 대하여 정적하중 시험을 통한 전단성능 평가 결과 홀드다운 적용 후에 전단벽의 초기강성, 항복하중 및 기준하중이 향상됨을 확인하였으며, 전단성능 향상에 따라 수평 변위와 전단변형의 증가율이 감소하는 것이 확인되었다. 홀드다운과 스터드의 접합방법에 따른 전단성능의 차이는 크지 않은 것으로 확인하였고, 홀드다운 제품 설계강도가 증가할수록 전단벽의 전단성능도 증가하는 경향이 나타났으나 그 차이가 제품 설계강도 차이에 비하여 크지 않은 것으로 판단되었다. 홀드다운을 설치하는 스터드의 규격에 따라서 89 mm 스터드를 사용한 경우와 38 mm 스터드를 두 겹으로 사용한 경우에 비슷한 성능을 나타내므로 38 mm 부재에 홀드다운을 설치할 경우는 스터드의 두께 보강을 통한 성능 향상이 필요하다고 판단하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.133-136
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• 2002

This paper discusses the design of a sample-and -hold amplifier(SHA) that has a 12-bit resolution with a 100 MS/s speed. The sample-and-hold amplifier uses the open-loop architecture with hold-mode feedthrough cancellation for high accuracy and high sampling speed. The designed SHA is composed of input buffer, sampling switch, and output buffer with additional amplifier for offset cancellation Hard Ware. The input buffer is implemented with folded-cascode type operational transconductance Amplifier(OTA), and sampling switch is implemented with switched source follower(SSF). A spurious free dynamic range (SFDR) of this circuit is 72.6 dB al 100 MS/s. Input signal dynamic range is 1 Vpp differential. Power consumption is 65 ㎽.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.17-20
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• 2011

The International Association of Classification Societies (IACS) had developed the Common Structural Rules (CSR) for bulk carriers as per the needs noted above. ISO and IMO GBS (Goal-Based Standards) are now being developed in this regard. This study has been prepared to verity the strength of forward cargo hold of 82,000 DWT class bulk carriers. A cargo hold/tank 3-D FE model was established to assess the structural adequacy of the primary structural members with the loading conditions. Full breadth model was established for the analysis considering asymmetric nature of structural layout and loading conditions. To summarize this result of structural assessment based on IACS CRS for bulk carrier, it is benefit to design this kind of bulk carriers and to study the strength assessment for the similar type of bulk carriers.

• 한국자기학회지
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• 제15권6호
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• pp.332-335
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• 2005

자속계의 경우 입력전압을 적분하여야 되기 때문에 연산증폭기의 입력 바이어스 전류가 있으면 적분기의 출력이 드리프트하게 된다. 본 연구에서는 이 드리프트를 자동으로 측정하고 보상하기 위하여 전압변동이 없는 디지털 sample and hold증폭기를 자속계에 도입하여 제작하였다. 개발한 자속계의 경우 적분기의 시간상수 $RC=10^{-3}$ s에서 드리프트가 $5{\times}10^{-8}\;Wb/s$ 이하였다.

• 대한소아치과학회지
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• 제5권1호
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• pp.12-18
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• 1978

The author has observed the ectopic eruption pattern on oblique cephalogram of 195 children. (5years: 78, 6 years: 58, 7 years: 59). The results were as follows; 1) Making a comparison between hold type and jump type of ectopic eruption, there are 4 cases in Hold type, 5 cases in jump type. 2) Making a comparison of ectopic eruptin between male and female, there are 7 cases in male, 2 cases in female. 3) Making a comparison of ectopic eruption between right side and left side, there are 5 cases at right side, 4 cases at left side. 4) Making a comparison of ectopic eruption among 5 years to 7 years, there are 4 cases in 5 years, 3 cases in 6 years, 2 cases in 7 years. 5) The prevalence of ectopic eruption of the maxillary first molar was 4.61%. 6) Normal eruption angle of the maxillary first molar is prevailing in $80^{\circ}{\sim}85^{\circ}$.

• 대한기계학회논문집
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• 제9권2호
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• pp.140-149
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• 1985

본 연구는 오오스테나이트계 STS 316 스테인레스강에 대하여 온도 550.deg. C의 대 기중에서, 변형율제어에 의한 인장-압축에 크리이프 유지시간을 갖는 고온저사이클 피 로시험을 하여 변형율폭 및 크리이프 유지시간이 피로수명에 미치는 영향과 파단면을 주사형 전자현미경으로 관찰하여 크리이프-피로 상호작용이 피로파단면에 미치는 크리 이프 효과를 실험 고찰하였다.

• 수산해양기술연구
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• 제44권2호
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• pp.148-156
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• 2008

In this study it will be discussed how to solve the problem of discomfort from rolling motion on the fishing boats. Most discomfort is caused by the short cycle of rolling due to the light weight of the boats. The light weight is due to the FRP material which dries a boat. A way to improve the feeling of boarding by using fish hold was researched. The experiment was done on experimental fishing boat made by FRP in Jeju. An existing fish hold was designed and manufactured through the rolling test and that was used for a marine experiment. The rolling condition of the U-tank boat ideally designed was compared to that of an existing fishing boat using the same conditions. The experiments were carried out two times on the stop engine in the outward Sehwa fishing port, which the experimental data had analysed for effects of rolling reduction to compare the U - tank with the of exiting fish hold. The results were confirmed that the U-boat tank in the roll period and GoM were more safe than the existing fish hold and the average amplitude and significant of rolling angles were decreased relatively.

• 한국안전학회지
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• 제15권2호
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• pp.8-12
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• 2000

The fatigue crack propagation tests were performed in triangular and holding-time stress waveforms at $650^{\circ}C$. The behavior of fatigue crack propagation was investigated according to waveform. The analysis of high temperature fatigue crack propagation by the stress intensity factor range ${\Delta}K$, elastic fracture mechanics parameter, was not available. The behaviors of high temperature fatigue crack propagation by the J-integral(${\Delta}J_f$, J' and ${\Delta}J_c$), elasto-plastic fracture mechanics parameter, were investigated in a number of stress waveforms. The fast-fast waveform exhibited cycle-dependent(fatigue type), the slow-fast and the hold time with 500sec waveforms appear to be time-dependent(creep type) and the fast-slow and the hold time with 5, 25sec waveforms exhibited conbined behavior of both types(fatigue-creep conbined type).

• 반도체디스플레이기술학회지
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• 제7권2호
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• pp.29-33
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• 2008

LCD panels are increasingly used to show moving image material, for example in LCD television sets. However, moving images become blurred on LCD panels. One of the causes of motion blur is the slow reaction of LC(liquid crystal) cell to change in the pixel value. Another cause of motion blur is the hold-type characteristic of the LCD panel, during the frame time the image is shown continuously. This type of motion blur can be reduced with a scanning backlight. We have designed and fabricated a scanning backlight system that solves the hold-type characteristic problem in a way that Flat fluorescent lamp divided 6 blocks was scanned 60Hz.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.277-280
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• 2008

Recently, a demand of nano/micro patterned polymer for display or biochip has been rising. Then many studies have been carried out. Nano/micro-embossing is a deformation process where the workpiece materials is heated to permit easier material flow and then forced over a planar patterned tool. In this work, the hot-emboss process is performed with different forming conditions; forming temperature, load, press hold time, to get the proper condition for linear pattern fabrication on plated-type polymers (PC). Replicated pattern depth increases in proportion to the forming temperature, load and time. Reduction of the workpiece thickness increases according to press hold time. In process of time, reduction ratio of workpiece thickness decreases because of surface area increment of the workpiece and pressure decline on it.