• 한국재료학회지
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• 제13권11호
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• pp.732-736
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• 2003

A CP-GFRP(Carbon Powder-Glass Fiber Reinforced Plastic) sensor was fabricated for fracture detection. The electric resistance of the sensor was measured on condition of various composition of carbon powders and thickness of bundle of glass fibers. The resistance of the sensor was decreased as the increase of the content of carbon powders and the TEX of the glass fibers. In the case of loading on CP-GFRP, because inner crack was propagated, the part of percolation structures was disconnected. These observations show the following results. The conduction of CP-GFRP sensor is due to percolation structure of carbon powders and increase of resistance is due to expansion of cracks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.82-84
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• 2003

In case contact between point of contacts is not achieved well, contact resistance is grown, and by current concentration at current conducting contacts can weld. In order to decrease contact resistance between contacts in case of busbar, installing spring between fixed contact and moving contact. and then force on faying surface of contacts increase and contact resistance decrease. But, in case increase force of spring to widen contact area, operating force moving contact can grow, on the contrary force of spring is small, contact resistance becomes low. Therefore, need to optimize force and number of spring. position, and also need to examine force change on contact surface at point of contact moving. In this paper, dynamic kinetics analysis for force on faying surface of contacts is performed at unsteady state. It is showed to not uniform force on surface between contacts, and we can got more uniform force by means of change spring position.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.349-352
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• 2009

In this study, the relation between the performance degradation of SOFC single cell and the increase of polarization resistance for the cathode is investigated. $Pr_{0.3}Sr_{0.7}Co_{0.3}Fe_{0.7}O_3$(PSCF3737, $19.4{\times}10^{-6}K^{-1}$) and $Gd_{0.1}Ce_{0.9}O_2$ (CGO91, $12{\times}10^{-6}K^{-1}$) are used as a cathode and an electrolyte, respectively. The polarization resistance of cathode is increased due to the delamination caused by thermal expansion coefficient difference. The voltage drop with 10%/1000h decline rate occurs during long-term, when the interface between the cathode and the electrolyte is delaminated due to TEC difference.

• Progress in Superconductivity
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• 제9권2호
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• pp.188-192
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• 2008

We investigated the size effect on quench development in $Au/YBa_2Cu_3O_7$ (YBCO) thin film meander lines on sapphire substrates. The meander lines were fabricated by patterning YBCO films coated with gold layers. The lines were subjected to simulated AC fault current, and immersed in liquid nitrogen during the experiment. After the initial rapid rise, the resistance increased moderately and then slowly. In 4 inch-diameter meander lines, the period during which the resistance increased moderately was considerably longer than in 2 inch-diameter line. Moderate increase of resistance was originated from quench propagation. The film temperature was about 180 K at the point when the propagation was completed. The rate of resistance increase after the quench completion was not affected by the film size.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.161-162
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• 2018

In this study, it evaluate the impact resistance of UHPC by repeated impact. smooth steel fiber and polyvinyl alcohol fiber were reinforced in UHPC respectively. Overall, the impact resistance of the specimens reinforced with 0.4vol.% PVA fiber was high, and the crater diameter was small in specimens using 13mm fiber. When 19 mm steel fiber is used, the fracture depth is small due to the increase of macro crack resistance compared with other specimens. On the other hand, in the case of the fracture area, it is considered that the use of the fiber of 13 mm causes an increase in the stress dispersion effect to occur small.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2082-2087
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• 2008

The heat transfer process from steam to web through the cylinder drum consists of the thermal resistance by condensate thickness. thickness of shell, and the contact resistance between cylinder and web. The most thermal resistance in conventional cylinder drum dryer is generated by condensate, which is increased by the increase on revolution per minute(RPM). Therefore, the increase of RPM for the production enhancement results in the more thermal resistance, and eventually RPM is restricted. In this study, the theoretical analysis on the characteristics of heat transfer in cylinder drum for paper dryer was performed in the stationary state of steam in drum. The overall heat transfer coefficient, steam quantity and heat transfer quantity were predicted by diameter and length of drum, condensate thickness, revolution per minute and steam temperature for experimental apparatus design.

• 한국재료학회지
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• 제29권7호
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• pp.408-411
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• 2019

ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.

• 한국해양환경ㆍ에너지학회지
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• 제18권4호
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• pp.298-303
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• 2015

해상에서 사고선박을 예인하기 위해서는 파랑과 바람 등 각종 외력의 상태와 표류각 등 선체 자체의 상태에 대한 피예인선의 저항 증가를 정확하게 추정하여야 한다. 대부분의 사고 선박은 선체 정면 방향으로 예인되지 못하고 일반적으로 표류각 만큼 기울어진 상태로 예인된다. 이러한 표류각에 의한 저항 증가는 무시할 수 없는 정도이다. 본 논문에서는 기존의 각종 표류각에 의한 저항 증가 추정 방법을 고찰하였다. 또한 표류각에 대한 새로운 방법 즉 정면-측면 투영면적 비율 방법과 다중회귀분석에 의한 경험식 방법을 도출하였다. 이 정면-측면 투영면적 비율방법은 예인상태 추정 프로그램에 적용되었고, 이 방법은 실제 상황에서 유용한 방법이라 확인되었다.

• Current Research on Agriculture and Life Sciences
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• 제20권
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• pp.83-90
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• 2002

역병 저항성 재료로 도입하여 유지하고 있는 PI123469, PI201234, PI201232, AC2258 (=Line 29), CM334, KC268, KC358, KC820, KC821, KC822, KC823 (Line 29 = AC2258), KC462, KC463, KC464 혹은 이들 유전자원에서 선발한 계통들의 역병에 대한 저항성 검정, 원예적 특성 조사 및 종자증식을 실시하였다. PI123469, PI201234, PI201232, AC2258, KC823에서 선발된 계통들이 가장 저항성이 강한 것으로 나타났다. 동일한 유전자원에서 선발한 계통 간에도 저항성 수준에서 현저한 차이가 관찰되는 경우가 있었으며, 이러한 경우는 주로 유지 증식과정에 자연교잡이 일어난 결과로 추정되었다. 따라서 순도 높은 저항성 재료를 얻기 위해서는 봉지를 씌워 자식종자를 채종하는 것이 가장 안전하며, 다음으로는 계통 망실 혹은 망상을 이용하는 것이 바람직한 것으로 판단되었다.

• 대한물리치료과학회지
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• 제25권3호
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• pp.17-24
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• 2018

Purpose: The purpose of this study was to investigate the effect of whole body vibration combined breathing resistance on lung capacity and respiratory muscle and to suggest a mediation method for improvement of respiratory function and lung function in the future. Methods: This study was a preliminary study design of two groups of 54 healthy young adults who were randomly assigned to an experimental group (n=27) with core exercise combined with respiratory resistance and whole body vibration and a control group with respiratory resistance and core exercise (n=27). All interventions consisted of 6 core exercises every 40 seconds and rest for 20 seconds. To compare the effects of intervention, we measured spirometry and respiratory muscle strength. Results: Both the experimental group and the control group showed a significant increase in Forced vital capacity (FVC) and Maximum voluntary ventilation (MVV) (p<.05). However, FEV1 and FEV1% were significantly increase only in the experimental group (p<.05). FVC, FEV1%, Maximum Inspiratory Pressure (MIP), Maximum Expiratory Pressure (MEP) showed more significant increase in the experimental group than the control group. Conclusion: These findings indicate that whole-body vibration combined breathing resistance is an effective intervention for people, with FVC, FEV1%, MIP, MEP increase.