• 주택과사람들
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• s.203
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• pp.44-47
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• 2007

완연한 봄 기운을 타고 4월이 활짝 열리면서 아파트 단지마다 이사 업체의 부산한 움직임과 사다리 차를 심심찮게 볼 수 있다. 내 집 마련, 전세 등 새로운 환경에서의 출발은 누구나 감회가 남다르다. 그러나 정작 이삿짐을 옮길 때는 정신이 없어 이것저것 빠뜨리기 십상. 이사할 때 챙겨야 할 사항들을 꼼꼼히 체크해봤다.

• 건강소식
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• v.35 no.1
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• pp.34-35
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• 2011

혹시 요즘 부쩍 몸이 붓거나 소변에 이상이 있는가? 아침에 자고 일어나면 눈 주위가 부어 있다거나 저녁쯤 되어 다리가 붓고 소변을 볼 때 불편하다면 신장에 이상이 없는지 확인해 봐야 한다. 우리 몸에서 작지만 아주 중요한 역할을 하는 신장을 건강하게 지키기 위해서는 스스로 몸 상태를 정기적으로 체크하는 것이 중요하다.

• Industry Promotion Research
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• v.2 no.1
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• pp.9-13
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• 2017

This study deals with the check valve safety valve for residential gas piping. It can be manually shut off within 1 second in case of emergency, and it is possible to touch 3kg of pressure by hand force. To develop the technology so that it can be used repeatedly. Study results after first valve operation. And 0.61 seconds on average. Therefore, it was found that there was no problem in operation even when used as a safety valve. Third, it was found that all of the results of using the blocking ball diameter of 7mm were not abnormal. In this study, it is meaningful to develop the check valve safety valve of gas piping and verify the performance by testing with existing valve.

• Journal of Korean Electronics
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• v.27 no.4
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• pp.32-32
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• 2007

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.2
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• pp.111-119
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• 1997

The operating characteristics of the check valve in the clutch piston of an automatic transmission have a great effect on the shifting performance. This paper addresses the modeling, dynamic analysis, and optimization of the check valve. It was found that the vortex causes a pressure drop, which is related to the rotating speed of the clutch piston, oil volume discharged from the check valve, and valve geometry. Maximizing the oil volume discharged, geometry of the check valve is optimized. The results can be used to design an improved check valve which provides a suitable oil pressure curves for achieving smoother shifting.

• Journal of Aerospace System Engineering
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• v.12 no.2
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• pp.7-14
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• 2018

In this study, a new check valve was studied to improve the load pressure of a brake system with a small piezoelectric-hydraulic pump. During the pressurization process, the steady-state pressure at the load is affected by the ratio of the cross-sectional area of the check valve the chamber pressure and load pressure. Since the flow path cover of the check valve is made wider than the cross-sectional area of the output flow to prevent backflow, a method of reducing the area ratio is proposed for a higher load pressure by mounting an additional mass to a thin plate spring type check valve. To identify the effect of mounting an additional mass to the existing check valve on the load pressure, a simple brake system with a small piezoelectric-hydraulic pump was modeled using a commercial code AMESim. The AMESim modeling was verified by comparing the simulation results with the experimental results of the pump the existing check valve. The additional mass was added to the verified AMESim modeling and higher load pressure was able to be obtained through simulation. The 35% performance improvement in load pressure identified by carrying out pressurization test of the brake system after adopting the new check valve the small piezoelectric-hydraulic pump.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.32-39
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• 2018

In this paper, the calculation of the theoretical pressure transfer ratio due to the deformation of the thin-plate spring type check valve applied to the small piezoelectric-hydraulic pump was carried out. A thin-plate check valve is a flexible body that is deformed by an external force. The deformation of the check valve affects the rate at which the chamber pressure is transferred to the load pressure. The theoretical pressure transfer ratio for each model was calculated to compare the difference between the assumption that the thin-plate check valve is a rigid body and that of the flexible body model. The P-delta effect was considered for the calculation of the pressure transfer ratio of the flexible check valve model. In addition, a verification test for the calculated pressure transfer ratio obtained by considering the deformation of the flexible check valve model was carried out. The load pressure was measured by applying a thin-plate and ball-thin plate spring type check valves, respectively. The experimental pressure transfer ratio was calculated using the respective load pressure obtained from the experiments. The validity of the pressure transfer analysis of the check valve, taking into consideration the P-delta effect, was verified by comparing it with the theoretically calculated pressure transfer ratio.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.401-402
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• 2017

본 논문에서는 아두이노와 스마트 폰 어플리케이션을 이용한 수중탐사로봇을 구현하였다. 구현된 시스템은 스마트폰으로 간편하게 조종을 할 수 있으며, 한눈에 알아보기 쉽게 수중의 영상 및 온도와 ph값, 수질 오염도를 체크할 수 있다. 양식업 사업에서 실시간으로 체크해 빠른 대처와 조치를 취할 수 있어 효율적으로 양식업을 관리 할 수 있다는 점에서 기대효과를 볼 수 있다. 또한 해양사고 발생 시 수중탐사로봇이 먼저 투입하여 인명구조를 하는 인력과 제 2의 피해자가 최소화 될 수 있고 더 이상 인명피해가 나지 않도록 안전적인 측면에서도 기대할 수 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.1
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• pp.284-294
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• 1996

In this paper, dynamic characteristics of an AT clutch system were investigated considering the dynamics of check ball and hydraulic control valves. Dynamic model of a pressure control solenoid valve (PCSV) was obtained by Bondgraph and permeance method. Also, the clutch piston and check ball dynamics were modeled by considering the effect of centrifugal force of the oil entrapped in the clutch chamber. In order to validate the dynamic models obtained, plunger displacement of PCSV and pressure response of the clutch supply lines were compared with the available experimental data, which were in good accordance with the numerical results. Using the dynamic model of the clutch system, simulations were performed to investigate the effect of the rotational speed on the response of clutch cylinder pressure, clutch piston and check ball displacement, and oil flow rate into the cylinder and flow rate out of the check valve.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.886-889
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• 2014

차량이 도로를 달리는데 있어서 절대적으로 꼭 필요한 타이어의 기능으로는 자동차의 하중을 지탱하고 자동차의 방향 전환 유지와, 노면 충격을 흡수 완화하며, 엔진의 구동력과 브레이킹 시 제동력을 노면에 전달하는 등의 기능이 있다. 이런 기능을 수행함에 있어 타이어의 상태는 안전과 직결된다고 볼 수 있다. 주행 중 운전자가 아무리 운전을 잘한다고 하더라도 타이어의 불량으로 인한 사고를 방지할 수는 없다. 자동차의 주행 안정성을 위한 타이어의 문제 중 타이어의 편마모는 운전자의 운전습관과 휠 얼라이먼트의 이상 등으로 타이어의 특정 부위가 마모되는 증상을 일컫는데, 현재까지 점검 방법으로는 정비사가 타이어를 눈과 손으로 점검하여 판단하고 있어서 점검하는 기준이 주관적이며, 정확하게 검증할 수 없는 것이 현실이다. 이에 본 논문에서는 현실의 애매모호한 주관적인 검증기준의 단점을 보완하고자 타이어의 실제 이미지를 디지털 영상처리 기법을 사용하여 각 타이어의 마모 정도를 체크하여 편마모를 객관적으로 점검할 수 있는 시스템을 설계하고자 한다.