나노 임프린트 장비 환경제어를 위한 초정밀 온도 제어에 관한 연구

박경서(Kyungseo Park),송영중(Youngjoog Song),임홍재(Hongjae Im),장시열(Siyeol Jang),이기성(Keesung Lee),정재일(Jay Il Jeong),신동훈(Donghoon Shin) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. also an air cooling process using unit take account of air current analysis in chamber is important. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and one air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR(Silicon Control Rectifier) control the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The control is heating and cooling at the same time by PID controller. So reducing temperature control error. The unit is consists of an air cycle method, so reduce the time and easy to contl. also Optimizing an air current contributive improves performance of nanoimprint

고효율 세라믹 열교환기 설계를 위한 이론해석 및 CFD시뮬레이션에 관한 연구

박경서(Kyungseo Park),최종균(Chong Gun Choi),남진현(Jin Hyun Nam),신동훈(Dooghoon Shin),정태용(Tae Yong Jung),박상환(Sanghwan Park),김창삼(Chang-Sam Kim) 한국에너지학회 2008 한국에너지공학회 학술발표회 Vol.2008 No.-

현재 대부분의 산업용 열기관은 효율을 높이기 위하여 연소에 사용되는 공기를 예열하는 방법을 사용한다. 하지만, 산업용 열기관에서 평균적으로 발생되는 1000℃ 이상의 배기가스는 일반 금속 열교환기에는 적합하지 않다. 이에 반해 세라믹 열교환기의 경우 고온에서 견디는 장점이 있다. 본 연구에서는 기본적인 열교환기 설계 이론을 이용하여 설계프로그램을 제작하였다. 또한 세라믹 열교환기 내 열 유체 거동을 CFD 상용코드인 FlUENT 6.2를 이용한 전산해석을 수행하여 설계결과를 비교 검증하였다. 설계 결과에서 휜의 형태 변화에 따라 열전달율과 온도구배는 무시할 수 있을 정도로 작았으나, 압력강하는 크게 변동되는 결과가 도출되었다. 제한된 모듈 크기에서 휜 간거리는 휜의 두께에 비해 약 3배 이상 클 경우가 적당하며, 판(plate)의 두께는 작을수록 압력손실이 적고, 열전달율이 상승하지만 두께가 너무 얇게 된다면 제작상의 어려움이 생긴다. 향후 연구에서는 단순한 구조에서 벗어나 off-set이나 판형구조를 고려하여 설계함으로서 열전달 면적을 넓히거나 난류유동을 발생시켜 열전달율을 높이는 연구를 진행 할 필요가 있다.

고효율 세라믹 열교환기 설계를 위한 이론해석 및 CFD시뮬레이션에 관한 연구

박경서(Kyungseo Park),남진현(Jin Hyun Nam),신동훈(Dooghoon Shin),정태용(Tae Yong Jung),박상환(Sanghwan Park),김창삼(Chang-Sam Kim),Chong Gun Choi 한국연소학회 2008 KOSCOSYMPOSIUM논문집 Vol.- No.-

Currently, most of the recuperator using stainless steel, however, this severely limits due to high-temperature corrosion / oxidation of metallic materials and chemical erosion by impurities of fuel. Ceramics, an alternative to metals, offer the potential to high temperature (over 1300℃) and corrosive environments. However, a ceramic recuperator analysis still leaves much to be desired. The purpose of this paper is to design a optimum ceramic recuperator, considering a high degree of transfer and according to thermal stress. A analysis model is investigated as a basis for thermodynamic associated with high-temperature recuperator, and then the analysis model is used to find the optimum design factor on the variation of recuperator condition. The result of this study are as follows : Thinner fin-plate thickness reduces pressure drop and increases heat-transfer rate, however, fin-plate having very thin thickness are difficult to manufacture and a weak thermal stress.

어머니의 양육행동 및 양육효능감이 어머니와 유아의 그림책 읽기 상호작용에 미치는 영향

박경서 ( Kyungseo Park ),이시자 ( Sija Lee ) 미래유아교육학회 2015 미래유아교육학회지 Vol.22 No.4

본 연구는 어머니의 양육행동 및 양육효능감과 그림책 읽기에서의 상호작용 유형 간에 관련성을 알아보고자 수행되었다. 이를 위해 만 4세 유아의 어머니를 대상으로 설문지 조사를 실시한 결과는 다음과 같다. 우선, 어머니의 사회 인구학적 변인 가운데 연령이 낮을수록 즉각적 상호작용을, 학력이 높을수록 비즉각적 상호작용과 생활지도를 그리고 가정의 수입이 높을수록 비즉각적 상호작용과 확장적 상호작용을 더 빈번히 행해지는 것으로 나타났다. 한편, 양육 행동 및 양육효능감과 그림책읽기 상호작용의 유형들 간에 유의미한 정적 관련성을 확인하였다. 그림책 읽기 상호작용 유형에 미치는 양육행동과 양육효능감의 상대적 영향력을 조사한 결과, 양육행동 중 애정성과 합리적 지도는 그림책 읽기의 즉각적 상호작용에, 양육행동 중 애정성과 합리적 지도, 그리고 어머니의 양육효능감은 비즉각적 상호작용에 영향을 미치는 주요 요인으로 조사되었다. 또한 양육행동 중 합리적 지도, 반응성, 그리고 어머니의 양육효능감은 그림책 읽기의 확장적 상호작용에 영향을 미치는 주요 요인이며, 생활지도성의 상호작용의 경우는 양육 행동 중 애정성만 영향을 미치는 요인으로 확인되었다. 본연구 결과는 앞으로 어머니와 유아의 그림책읽기 상호작용이 효과적으로 이루어지도록 부모 교육 프로그램을 계발할 때 기초자료로 활용될 수 있을 것이다. The purpose of this study was to examine the influence of mothers’ parental behaviors and maternal self efficacy on the interaction types of picture book reading. A questionnaire survey for the mothers of 4 year old children was conducted and analysed with the methods of correlation and regression. The result of the study could be summarized as follows: First, in terms of the mothers’ socio-demographic variables, the younger the mothers’ ages the more they tended to practice immediate comments, the higher their education level the more non-immediate comments and organizational comments, and the higher the household income the more non-immediate comments and extending comments. Second, positive relationships of parental behavior and maternal self-efficacy with the interaction types of picture book reading were significantly confirmed in the way that the intimacy and the reasoning guidance of parental behavior turned out to be the major factor on the immediate comments in picture book reading, intimacy and reasoning guidance of parental behavior and maternal self-efficacy on non-immediate comments, and the reasoning guidance and responsiveness of parental behavior and maternal self-efficacy on extending comments, while in the interaction of organizational comments only the intimacy was the influencing factor. The study could serve as a reference in developing the parents education programs that can promote effective interactions between mothers and children in picture book reading.

열전소자를 이용한 정밀 항온 유지 장치에 관한 실험 및 시뮬레이션 연구

박경서(Kyungseo Park),송영중(Youngjoog Song),임홍재(Hongjae Im),장시열(Siyeol Jang),이기성(Keesung Lee),정재일(Jay Jeong),신동훈(Donghoon Shin) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and two air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR controls the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The temperature control unit is able to control the exit temperature about ±2℃ from the incoming fluid temperature, and the error range is ±0.1℃. However, the control time is approximately 30minute, which needs further study of active control

고온용 세라믹 열교환기 설계를 위한 수치 연구

박경서(Kyungseo Park),최종균(Chong Gun Choi),남진현(Jin Hyun Nam),신동훈(Dooghoon Shin),박상환(Sanghwan Park) 한국연소학회 2009 한국연소학회지 Vol.14 No.3

To improve its efficiency, most of the industrial furnace had been used recuperator. However, commonly used metal recuperator is not suitable under condition of temperature higher than 1000℃. The other hand, ceramic recuperator is able to use in high temperature condition. In the present study, the design program based on the basic heat exchanger design theory, and CFD modelling are applied to ceramic recuperator to verify the design results. Using design program to find the optimum design factor on the variation of recuperator condition. The result of this study are as follows : Thinner fin-plate thickness reduces pressure drop and increases heat-transfer rate, However, thin plate or plate with thin thickness(< 5 ㎜) is difficult to manufacture, due to limited mechanically strength.

현가 장치 볼 조인트 부품의 Stick Slip 소음 검증 방법 향상

손명군(Myungkoon Son),김영표(Yeongpyo Kim),박경서(Kyungseo Park) 한국자동차공학회 2019 한국자동차공학회 학술대회 및 전시회 Vol.2019 No.11

폐열회수 환기장치의 열교환 효율 개선을 위한 전산수치해석

김현일(Hyun-il Kim),김재성(Jaesung Kim),박철우(Chulwoo Park),박경서(Kyungseo Park) (사)한국CDE학회 2012 한국CDE학회 논문집 Vol.17 No.1

In this paper, we performed numerical analysis to improve the heat exchange efficiency of wasted heat recovery ventilator which has a delivery and a exhaustion fan. One of the most important design factors that affect the efficiency of heat exchange is uniform counter-flow between inbound and outbound air flows. We had simulated several types of porous plates which were installed at air intake area. With plate having 45 degrees of installation angle and 15 mm diameter holes which are uniformly arranged, we can generate a uniform air flows at the area of porous media where inbound and outbound air flows are cross over. In addition, we installed a duct to reduce vortex flows at the outlet and to discharge exhaust airs rapidly. By using the proposed numerical assessment, we expect the improvement of the heat exchange efficiency of ventilator.