• Title/Summary/Keyword: 온도변화

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Structural Behavior of Concrete Pavement Due to Temperature Variations (온도변화에 의한 콘크리트 포장도로의 구조 거동 연구)

  • 조병완
    • Computational Structural Engineering
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    • v.4 no.2
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    • pp.95-102
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    • 1991
  • Some sections of concrete highway pavements have been viewed with great concern by highway officials and engineers due to the severe cracking and failure problems. This is mainly due to the traffic loads in addition to temperature variations between top and bottom of concrete slab, which cause the concrete slab to curl up and down depending on the thermal gradient, respectively. Subsequently, a major consideration was given to the derivation of stiffness matrix and equivalent nodal loads due to the uniform gravity load, temperature and shrinkage of concrete. And the structural behavior of concrete highway pavement due to the temperature variations throughout the nations has been emphasized.

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CFD Analysis Based Optimal Temperature Measurement (CFD 해석 기반 실내 최적 온도 계측)

  • Lee, Min-Goo;Park, Yong-Kuk;Jung, Kyung-Kwon;Yoo, Jun-Jae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.735-738
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    • 2011
  • This paper proposed the method to find out the optimal sensing point of temperature in test-bed with the sensor of temperature, such as real residence. We selected optimal locations by checking temperature change which was simulated by the means of CFD (Computational Fluid Dynamics) and the variation of air flow. We installed 30 temperature sensors in real place. After that, we compared the real one with the result of simulation.

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A Study on the Temperature Change of Braking Disc and Thermal Conductivity during the Service (철도차량용 제동디스크의 운행중 온도 변화 및 열전도도 측정 연구)

  • Kim, Jae-Hoon;Goo, Byeong-Choon;Suk, Chang-Sung
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.665-669
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    • 2007
  • This study investigates the temperature change and thermal conductivity for the braking disc of the railway vehicle due to the types of train and service conditions. The temperature change was measured by non-contact Infrared thermometers. Average temperature was measured between $79.32^{\circ}C$ and $104.46^{\circ}C$ due to types of train and service section. In the same service section, the surface temperatures of Saemaul train were higher than Mugungwha train; the reason might have been the average service speed of Saemaul train (83km/h) was higher than Mugungwha train (107km/h), and the weight was similar 39t (Mugungwha) and 39.3t (Saemaul). But the maximum surface temperature was measured on the Mugungwha train; however the difference was not too big with the maximum temperature of Saemaul train. Also, the disc surface temperatures were changed due to the material of lining; metal and non-asbestos, on the same train and the same service section. In addition. the thermal conductivity was tested the thermal conductivities were increased by the increasing of the temperature. The change is too big between $100^{\circ}C$ and $200^{\circ}C$. But each average value is small. and the mechanical property change is very low. As a result, we conclude that this disc is suitable for usage between $100^{\circ}C$ and $300^{\circ}C$.

Optical Design of a Laser Scanning System Stable Against Wavelength and Temperature Variations (파장과 온도변화에 안정한 레이저 주사광학계 설계)

  • Kim, Da Ae;Lee, Jong-Ung
    • Korean Journal of Optics and Photonics
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    • v.27 no.1
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    • pp.32-40
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    • 2016
  • The characteristics of an optical system vary depending on wavelength and ambient temperature. Based on the thin-lens approximation, we investigate the conditions for stabilizing an optical system against wavelength and temperature variations at the same time. The conditions are applied to designing a laser scanning system consisting of two lenses. The change in the effective focal length of the scanning system against wavelength and temperature variations is very small, as expected.

Study of silicon deep via etching mechanism using in-situ temperature monitoring of silicon exposed to $SF_6/O_2$ plasma discharge

  • Im, Yeong-Dae;Lee, Seung-Hwan;Yu, Won-Jong;Jeong, Oh-Jin;Lee, Han-Chun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2009.10a
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    • pp.116-117
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    • 2009
  • 식각 공정변화 즉 상부 ICP 파워, 반응기 압력, 실리콘 기판 온도변화에 따른 실리콘 딥 비어 (deep via) 의 형상 변화 메커니즘을 연구하였다. 메커니즘을 연구하기 위해 $SF_6/O_2$ 플라즈마에 노출된 실리콘 기판의 공정변화에 따른 표면 온도변화를 실시간으로 측정하여 플라즈마 내 positive ions의 거동을 분석하였다. 실리콘 기판의 표면온도를 상승시키는 주된 요인은 positive ions임을 확인할 수 있었으며 이는 기판에 적용된 negative voltage로 인하여 나타난 이온포격이 그 원인임을 알 수 있었다. 상대적으로 radical은 실리콘 표면온도 상승에 큰 역할을 하지 못하였다. 기판 표면온도가 상승 할수록 실리콘 딥 비어 구조에 undercut, local bowing과 같은 측벽 식각이 활성화됨을 확인할 수 있었으며 이는 기판에 들어오는 positive ions가 측벽식각을 유도하는 것으로 해석할 수 있었다.

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Field Test of Tunnel Lining Temperature Variation Using Insulation Material (단열재를 활용한 터널라이닝 온도변화 현장 실험)

  • Jin, Hyunwoo;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.4
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    • pp.11-16
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    • 2019
  • The low temperature and temperature difference (variation) may cause to deteriorate the integrity of tunnel constructed in cold region. An insulation material was developed and applied to the tunnel lining surface to keep the temperature of tunnel lining constant in spite of temperature variation at outdoor. The lining surface where the insulation material applied showed the less sensitive to temperature variation than non-applied lining surface.

손상 핵연료의 온도 및 산소대 금속 비율의 변화 모형 연구

  • 서영하;박광헌;호광일
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05c
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    • pp.329-334
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    • 1996
  • 손상 핵연료의 온도 및 산소대 금속 비율의 변화모형을 연구하였다. 열역학적 분석과 산화과정에 대한 분석을 통해 손상핵연료에서의 핵연료 온도와 핵연료내 O/U값 변화를 기술함으로써 결함발생에 의한 핵연료내 냉각수 침투는 Gap conductance를 떨어뜨리고 소결체 산화에 따른 O/U값 증가로 열전달특성의 저하를 가져와 핵연료의 온도를 상승시킨다는 결과를 얻어냈다.

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수치모의를 통한 인천국제공항 건설 후 안개발생과 관련한 국지기상변화 고찰

  • 이화운;임헌호;김동혁
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2004.11a
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    • pp.185-187
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    • 2004
  • 인천국제공항 건설후 안개 발생과 관련한 국지 기상의 변화를 살펴보고자 하였다. 먼저 온도의 시계열 변화를 살펴 보았을 때 건설 전과 대비해 건설 후에 약 $2^{\circ}C$ 정도의 온도 상승효과가 나타났으며 지표면이 Urban일 경우 주간에 가장 온도가 높고 야간에 온도가 가장 낮게 나타났다.

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Optimal Measuring Point Selection Method of Indoor Temperature using CFD Analysis (CFD 해석을 이용한 실내 온도 최적 측정 위치 선정 방법)

  • Lee, Min-Goo;Jung, Kyung-Kwon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.7
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    • pp.1559-1566
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    • 2012
  • This paper proposed the method to find out the optimal sensing point of temperature in test-bed with the sensor of temperature, such as real residence. We selected optimal locations by checking temperature change which was simulated by the means of CFD (Computational Fluid Dynamics) and the variation of air flow. We made 3-dimensional model of the testbed using DesignBuilder software, and ran the CFD. We selected the optimum temperature measurement location of 1.5 m height from the floor and low temperature variation. The experiments were conducted 30 temperature and humidity sensors in real place. After that, we confirmed the results of temperature change.

Change of Surface Temperature in Woodceramics Made from MDF(I) -Effect of Density and Burning Temperature- (MDF로 제조된 우드세라믹의 표면온도변화(I) -밀도 및 소성온도의 영향-)

  • 오승원
    • Journal of Korea Foresty Energy
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    • v.21 no.1
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    • pp.1-6
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    • 2002
  • The following conclusions were obtained with measuring the surface temperature change of woodceramics which were made of MDF to identify usability of using them as a sub-material for heating system when installing Ondol heating floor. For this purpose, woodceramics were burned at the temperature of $650^{\circ}C$ and $800^{\circ}C$ 1. Surface temperature of woodceramics increased with the increase of density of woodceramics, but no significant difference was detected at the surface temperature when burning temperature was changed. 2. Surface temperature change under given temperature increased as time passed and it showed more increase in temperature at the burning temperature of 80$0^{\circ}C$. 3. Surface temperature change with the change in floor temperature increased u hen floor temperature increased and heating mechanism was fast with increase of measuring temperature.

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