유한요소해석과 실험을 통한 반도체칩의 변형예측

임재혁(Jae Hyuk Lim),한만희(Man-Hee Han),이준연(Jun-Youn Lee),박정순(Jeong Soon Park),엄윤용(Youn Young Earmme),임세영(Seyoung Im) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

Prediction of warpage and residual stress in semiconductor chip devices play an important role in chip design. However, there are a few uncertainties in warpage prediction due to unknown patterning material properties, and moisture effect on polymer film. To estimate patterning material properties, we adopt a composite plate analysis and experimental techniques. and measure the warpage of chip after drying at about 250℃ for 30min to remove moisture. In 100㎛, 80㎛ chip cases, finite element analysis result shows a good agreement with measured values, but for 50㎛ and 60㎛ chip cases, there exist a substantial deviation from the measured values due to local deformation from imperfection and defects inherently embedded in the patterning layer and nonuniform bonding between PIcoating and silicon.

오피스건물에서 구체축열시스템의 최적 제어 및 운전 방안

임재한(Jae-Han Lim),이윤선(Yoon-Sun Lee),이겨레(Keo-Re Lee) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.11

구체축열시스템은 구조체 축열로 인한 시간지연 특성을 고려하여 적절한 운전 제어를 통해 건물에서 최대 냉난방 부하를 저감함으로써 에너지 비용을 낮출 수도 있다. 반면, 국내의 고온다습한 하절기 기후 조건에서는 냉방운전시 방열면에서 결로 발생 위험이 상존하고 있다. 그러므로 본 연구에서는 오피스건물을 대상으로 적용방안을 도출하기 위해 기존 적용 사례 특성을 조사 분석하고, 동적 에너지해석 시뮬레이션을 통해 냉방운전시 결로방지 및 에너지 성능 특성에 대한 분석을 수행하였다. 이를 위해 우선 국내의 구체축열시스템 적용사례 및 국내 건축물 설계기준을 고려하여 오피스건물을 대상으로 건물 모델링을 구성하였고 이를 대상으로 구체축열시스템과 공조시스템의 통합운전인 구체축열 통합시스템을 구성하였다. 구체축열시스템과 변풍량시스템의 통합운전과 구체축열시스템과 외기전담공조시스템의 통합운전의 냉방에너지 성능을 비교하고 외기전담공조시스템 구성에 따른 냉방에너지 성능을 평가하였다.

초고층 복합건물에서 미활용에너지원으로서 하수처리수의 활용가능성 평가

임재한(Lim Jae-Han) 대한건축학회 2010 대한건축학회 학술발표대회 논문집 Vol.30 No.1

파워모듈 열특성을 고려한 HEV/EV 출력 성능 개선

임재상(Jae-Sang Lim),강구배(Gubae Kang),장한근(Han Geun Jang),박주영(Jooyoung Park),임성엽(SeongYeop Lim) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11

This paper presents an approach for constructing an electro-thermal model of IGBT-devices as inverters considering variable switching frequencies and battery voltage for HEV/EV. IGBT losses depend on current, battery voltage, and switching frequency. Conventional inverter system uses a fixed switching frequency, but variable frequencies operation is needed to reduce switching losses and decrease junction temperature of IGBT. This paper develops the loss function of IGBT thermal model when switching frequencies vary. As a result, a difference between real temperature and estimated temperature of IGBT is reduced and hill holding performance of HEV/EV is improved.

자동 격리를 감안한 슬래머 웜 전파과정에 대한 모의실험 및 분석

임재명,정한균,윤종호,Lim, Jae-Myung,Jung, Han-Gyun,Yoon, Chong-Ho 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.8b

본 논문에서는 2003년 전 세계의 인터넷망에서의 심각한 소통 장애를 일으켰던 슬래머 웜 보안공격의 전파 전과정을 NS-2를 이용한 시뮬레이터로 분석하였다. 기존 연구에서는 Detailed Network-Abstract Network(DN-AN) 모델 기반의 Abstract Network-Abstract Network(AN-AN)모델을 이용한 분석이 수행되었다. 이러한 AN-AN모델은 패킷 레벨까지 정확한 분석이 가능하지만, 초기 300초의 감염구간을 모의실험 하는데 240시간이 소요되는 시간상 문제점이 있었다. 본 논문에서는 이러한 문제점을 해결하기 위한 축소된 모델링 기법을 제시하여 모의실험에 필요한 소요시간을 단축함으로써 소통 장애가 일어난 3.5시간을 107시간에 분석할 수 있었다. 아울러 기존 분석에서는 감염 호스트가 인위적인 치료나 격리 조치가 있을 때까지는 모두 동작하는 것으로 가정하였지만, 슬래머의 과도한 감염 트래픽으로 중계 라우터의 동작이 중지되는 현상에 의해 해당 장비가 감염과정에서 자연적으로 격리되는 격리율 0.00022도 함께 고려하였다. 모의실험 결과, 국제관문국의 국외$\Longrightarrow$국내방향은 4,787초에 정상 상태로 돌아온 반면, 국내$\Longrightarrow$국외방향이 3.5시간동안 포화가 되어 소통 장애가 지속됨을 알 수 있었다. In this paper, we have analyzed a simulation model of Slammer worm propagation process which caused serious disruptions on the Internet in the year of 2003 by using NS-2. Previously we had presented and analyzed Abstract Network to Abstract Network(AN-AN) model being modified from the Detailed Network to Abstract Network(DN-AN) of NS-2. However, packet analysis in AN-AN model had a problem of taking 240 hours to simulate the initial 300 seconds of infection. We have reduced the AN-AN model to save the simulation time and analyzed total 3.5 hours of the network congestions within 107 hours. Moreover, we have derived optimal quarantine rate of 0.0022 considering service outage of network devices caused by the heavy infected traffics, which was not taken into consideration in previous works. As the result of simulation, Although the inbound traffic at the Korean international gateway was back in normal conditions at 4,787 second, due to the revese direction saturation was maintained until 12,600 seconds, the service outage was persisted for 3.5 hours.

피험자 실험을 통한 하절기 도심지 온열환경 조건에서 인체의 심박변이도 분석

임재한(Lim, Jae-Han) 한국건축친환경설비학회 2020 한국건축친환경설비학회 논문집 Vol.14 No.5

The urban thermal environment has been deteriorating these days due to global climate change and the occurrence of heat-related illness have emerged as the major social problems. This study is aimed to analyze the Heart rate variability (HRV) of human body based on the subject experiments in different urban thermal environments during summer. We measured the environmental conditions by PMV meter and thermal imaging camera. During the subject experiments, the measured R-R interval data by heart rate sensor (Polar H10) in two-minute interval were used for the analysis of HRV. LF/HF ratio was used for the HRV evaluation. Two subjects were tested in different environment conditions during summer. We analyzed the correlation between the urban thermal environment and HRV of human body. Statistically F-test and T-test were performed at 95% of the confidence intervals to see if the comparison of the data is significant. Given the differences between indoor and outdoor thermal environments, there was a significant difference in the HRV values . The variable that has a significant impact on the outdoor environment seems to be the sensitivity of the subject individual to environmental changes. The results showed that the direct solar incidence to persons or variation in the pavement material was not significant within a limited range of outdoor environmental conditions (2≦PMV≦3).

주거건물에서 취사기기 유형 및 운전 상황에 따른 실내공기 오염물질 발생 현황

임재한(Jae-Han Lim) 한국생활환경학회 2015 한국생활환경학회지 Vol.22 No.1

In most residential buildings, if ventilation of rooms is poor during their lives, indoor pollution can build up to levels which may be detrimental to human health. Especially cooking appliances that burn fuel are potential sources of indoor air pollution such as carbon dioxide. It is important that air is circulated in the indoor environment to make sure that harmful levels of gases or particles do not build up. This study focused on the evaluation of the effect of product type and operation condition of cooking appliances on the indoor air quality of residential buildings. Through the field experiments, dry-bulb temperatures, relative humidity and pollutants concentration such as CO, CO2, PM10 were measured in an apartment building and a detached house respectively during summer. We have analyzed the continuous variations of measured values according to the ventilation strategies. In results, the concentration of CO2 due to the gas range operation was not reduced below the guidelines of indoor air quality although the mechanical ventilator was operated and natural ventilated window was open. To remove the indoor air pollutants during the gas range operation in kitchen, it is not enough to open the natural ventilated window.

가돌리늄 첨가에 따른 2205 듀플렉스 스테인레스 강의 기계적 및 부식 특성 변화

임재한 ( Jae Han Lim ),안지호 ( Ji Ho Ahn ),문병문 ( Byung Moon Moon ),김영직 ( Young Jig Kim ) 한국주조공학회 2015 한국주조공학회지 Vol.35 No.6

This study reports the influence of gadolinium (Gd) addition on mechanical and corrosion properties of 2205 duplex stainless steel. In all alloys produced, regardless of the initial Gd content, Gd-based inclusions were well distributed in the duplex stainless steel matrix. As the Gd content increased from 0 wt% to 0.19 wt%, the ultimate tensile strength and hardness of the alloy increased from 630 MPa to 977 MPa and from 57 to 61, respectively, while elastic modulus, tensile elongation and impact energy of the alloy decreased. The critical crevice temperatures of Alloy1, Alloy2 and Alloy3 were 20oC, 20oC and 15oC, respectively.

온돌난방에서 경량기포콘크리트의 재료배합에 따른 방열성능 평가

임재한(Lim Jae-Han) 대한건축학회 2008 대한건축학회논문집 Vol.24 No.2

Normally, the lightweight foamed concrete is used for insulation layer and levelling layer in radiant floor heating. By changing the ratio of ingredients such as an admixture, the fundamental properties of the lightweight foamed concrete could be changed. Due to the conductivity of this material, the characteristics of thermal output could be changed. So this study was aimed to evaluate the thermal output in radiant floor heating due to the mixture of materials in an aerated concrete. Firstly, the current foreign standards regarding the thermal output of radiant floor heating were reviewed. Nextly, the conductivity of lightweight foamed concrete was measured when the admixture and stabilizing agent were added for performance improvements. Finally, thermal output and downward heat loss were evaluated by changing the design parameter such as pipe spacing and water temperature differences. As the results, we could conclude that the conductivity of lightweight foamed concrete could be lowered by 0.12W/mK compared to the KS F 4039. Also the downward heat loss could be lowered by 20%.

양액재배적응 유망 산채류선발

임재하(Lim Jae-Ha),한증술(Han Jeung-Sull),윤재탁(Yoon Jae-Tak),최동진(Choi Dong-Jin),김임수(Kim im-Soo),최부술(Choi Boo-Sull) 한국원예학회 1994 한국원예학회 학술발표요지 Vol.12 No.2