• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.456-463
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• 1997

Atrium buildings are commonly found in Hong Kong since 1980. Those spaces are usually crowded with people and so fire protection systems have to be installed for providing a safe environment. Smoke control system was identified to be important but no clear design guidelines are available because the smoke filling process was not well-understood. In this paper., Computational Fluid Dynamics(CFD) or fire field model is applied to study the smoke filling pattern in atrium. Two common cases on smoke spreading out from a shop adjacent to the atrium; and with a fire located at the atrium floor itself were considered. Simulations with a modified form of the CFD package TEAM were performed. Application of the predicted results Is illustrated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.272-273
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• 2013

Some living thingsuse micro- or nano- structures for living in nature. Scientists and engineers made efforts to mimic them, and they succeeded in making new types of applications. They used 'Namib desert beetle' to self-filling device by moisture harvesting and 'lotus leaf' to self-cleaning device by water repelling. 'Namib desert beetle' and lotus leaf have micro-patterns on their surface, which consists of hydrophobic or hydrophilic materials [1]. Moreover, micro-patterns on the surface make self-filling or self-cleaning property enhanced because of the surface roughness. Surface roughness enhances wettability [2]. Micro-pattern is a significant factor to make the surface be functional, so we want to make new types of functional surface by micro-patterning. In this work,we make several functional micro-patterns (radial, line, and dot arrays) using maskless lithography and analyze the characteristics of each micro-pattern. In order to analyze and understand surface characteristics, micro-patterns with varying sizes are investigated. All experiments are proceeded on mr-DWL5 photo resists coated on silicon wafers in same condition. All the experiments have demonstrated good performances about hydrophobic or hydrophilic property corresponding to their material and structural combinations. In radial micro-pattern, although the surface is flat, water drops on hydrophilic radial pattern can be convergent to a middle point and water drops on hydrophobic radial pattern can be divergent from the middle point. In line array micro-pattern, water drops can roll off along only one direction in parallel with the line arrays. Such phenomena might be mainly caused by the local change of surface roughness. From these results, controlling the movement and direction of water drops is made feasible without introducing a slope, which can potentially be used for new types of applications.

• 한국재료학회지
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• 제16권11호
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• pp.668-675
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• 2006

In the partial squeeze casting process, the filling behavior of liquid metal and solidification pattern in thick area have significant influence on the quality of casting products and die life. For the optimal casting design of automobile transmission gear housing, various analyses were performed in this study by using computer simulation code, MAGMAsoft and the simulation results were compared and analyzed with experimental results. By air pressure criteria, internal porosities caused by air entrap during the mold filling were predicted and reduced remarkably by modification of gating system. Also, optimal squeeze-time lag to apply partial squeeze pin in thick area was calculated and the castings was free from shrinkage defects with the result of solidification analysis. Consequently, casting design for automobile transmission gear housing was optimized and approved by Computer Tomography.

• 한국정밀공학회지
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• 제16권9호
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• pp.123-134
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• 1999

A new forming technology has been developed to fabricate near-net shape components by using aluminum alloys with globular microstructure. The estimations of filling characteristic in the forging simulation with arbitrarily shaped dies of SSM are calculated by finite element method with proposed algorithm. The proposed model and various boundary conditions for arbitrarily shaped die are investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation processes with arbitrarily shaped dies are performed on the isothermal conditions and axisymmetric problems. To analyze the forging process simulation with SSM, new stress-strain relationship for semi-solid behaviour is described, and forging the liquid flow. Furthermore, For the purpose of getting net shape of SSM, it is important to be obtain a solid fraction in forging process with arbitrarily shaped dies. To produce a automotive part which have good mechanical properties, the filling pattern in accordance with die velocity and solid fraction distribution has to be estimated for arbitrarily shaped die.

• 한국작물학회지
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• 제36권2호
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• pp.166-173
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• 1991

출수후 등숙기간 동안에 엽신의 노화속도와 동화산물의 전류특성과의 관계를 구명하며 등숙향상 및 단기등숙 품종육성을 위한 선발지표를 제공코자 엽신의 노화정도가 다른 올보리외 29품종 및 계통을 공시하여 엽신 노화율, 등숙율 및 상호 상관관계를 조사하였던 바 결과를 요약하면 다음과 같다. 1. 엽신의 노화속도 및 입충전속도(등숙율)는 계통에 따라 큰 차이가 있었다 2. 등숙초ㆍ중기(출수후 10-20일) 및 등숙중ㆍ후기(출수후 20-30일)의 엽신 노화율과 해당 각 시기의 등숙율과는 높은 정의 상관관계가 있었다. 3. 등숙초ㆍ중기의 엽신 노화율과 등숙전기간(출수후 10-35일)의 등숙율과는 부의 상관이 등숙중ㆍ후기의 엽신 노화율과는 고도의 정의 상관관계가 있었다. 4. 입중과 등숙중ㆍ후기 및 등숙전기간의 등숙율과는 고도의 정의 상관관계가 있었으나 등숙초ㆍ중기의 등숙율 및 등숙일수와는 상관이 없었다. 5. 노화지수의 감소 양상은 계통에 따라 4가지 유형으로 분류할 수 있었는데 종실수량 및 등숙율면에서 가장 이상적인 유형은 IV형이었다 6. 본 시험결과 단기등숙형 대맥 품종으로 가장 이상적인 형은 등숙초ㆍ중기에는 노화지수가 높으면서도 노화속도가 느리나 등숙중ㆍ후기에는 노화속도가 빠른 품종임이 구명되었다.

• Journal of Crop Science and Biotechnology
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• 제11권1호
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• pp.75-82
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• 2008

Functional stay-green is a beneficial trait that may increase grain yield through the sustained photosynthetic competence during monocarpic senescence in cereal crops. The temporal changes of photosynthesis and related characteristics throughout the grain filling period of a stay-green japonica rice "SNU-SG1" was compared in growth chamber conditions with three high-yielding cultivars(HYVs) and their $F_1$ hybrids with SNU-SG1. SNU-SG1 exhibited a typical characteristic of functional stay-green in terms of chlorophyll degradation and photosynthetic competence during grain filling. According to the photosynthesis-light response curve measured at 10 and 35 d after heading for the flag leaf, SNU-SG1 exhibited higher initial light conversion efficiency and thus higher gross photosynthetic rate at light saturation compared to HYVs. Light saturation point was not different among genotypes, ranging from 1000 to 1500 ${\mu}mol$ photon $m^{-2}s^{-1}$. Net photosynthetic rate at light saturation($P_{max}$) of the upper four leaves in SNU-SG1 was much higher and sustained longer throughout grain-filling than HYVs and $F_1$ hybrids. The sustained high photosynthetic competence of SNU-SG1 during grain filling was ascribed to the longer maintenance of high mesophyll conductance that resulted from not only high chlorophyll content and its delayed degradation but also the slow degeneration of photosystem II(PS II) as judged by chlorophyll fluorescence($F_v/F_m$) of flag leaves. $F_1$ hybrids showed slow degeneration of photosystem II similar to the male parent SNU-SG1 while chlorophyll degradation pattern close to female parents, thus exhibiting a little higher $P_{max}$ than female parents. These results suggest that SNU-SG1 has a typical functional stay-green trait that can be utilized for increasing rice yield potential through the improved dry matter production during grain filling.

• 소성∙가공
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• 제6권3호
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• pp.239-249
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• 1997

The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular. To optimal net shape forging of semi-solid materials, it is important to investigate for filling phenomena in forging process of arbitrarily shaped dies. To produce a automotive part which has good mechanical property, the filling pattern according to die velocity and solid fraction distribution has to be estimated for arbitrarily shaped dies. Therefore, the estimation of filling characteristic in the forging simulation with arbitrarily shaped dies of semi-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for arbitrarily shaped dies is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process with arbitrarily shaped dies is performed to the isothermal conditions of two dimensional problems. To analysis of forging process by using semi-solid materials, a new stress-strain relationship is described, and forging analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for forging force and filling limitations will be compared to experimental data. The filling simulation of simple products performed with the uniform billet temperature(584$^{\circ}C$) from the induction heating by the commercial package MAGMAsoft. The initial step of computation is the touching of semi-solid material with the end of die gate and the initial concept of proposed system just fit with the capability of MAGMAsoft.

• 한국토양비료학회지
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• 제6권2호
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• pp.95-105
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• 1973

IR667 계통(系統)(Suwon 213 및 214)과 장려품종(진흥(振興) 및 팔달(八達))의 수용기(受用器)(Sink) 및 급여기(給與器)(Source)의 크기와 그들간(間) 거리(距離), 동화산물의 형태(形態), 기상인자(氣象因子)와 관련(關聯) 수기(受器)(곡실(穀實))충전(充塡) 속도(速度)를 검토(檢討)하여 다음과 같은 결과(結果)를 얻었다. 1. IR667 계통(系統)은 장려 품종보다 최고수기충전속도(最高受器充塡速度)가 크고 빨리온다. 충전속도곡선(充塡速度曲線)의 양상(樣相)은 IR667 계(系)는 준봉형(峻峰型)을 장려품종은 구릉형(丘陵型)을 보인다. 2. 기상인자(氣象因子)는 충전곡선(充塡曲線)의 양상(樣相)에 큰 변화(變化)를 주지 못하는 것 같다. 3. 수기일급기간(受器一給器間) 기능거리(機能距離)(실거리(實距離)${\times}$각엽(各葉)의 생산기여율는 상위엽의존형(上位葉依存型)인 IR667 계(系)에서는 상위엽(上位葉)이 짧고 하위엽의존형(下位葉依存型)인 장려품중에서는 하위엽(下位葉)이 짧다. IR667의 상위엽의존성(上位葉依存性)이 유난히 짧은 제(第)1간장(稈長)(상부(上部)로부터)에 기인(基因)하는것 같다. 4. 간(稈)과 엽초의 유리당(遊離糖)/전분비(澱粉比)에 따라 IR667계(系)는 고당형(高糖型)으로 장려품종은 고전분형(高澱粉型)으로 분류(分類)되었으며 전이성(轉移性)(당(糖))과 비전이성(非轉移性) 동화산물(전분(澱粉))의 비(比)가 수기충전속도(受器充塡速度)와 관련되고 고당형(高糖型)이 생산효율이 높을 것으로 예상된다. 5. 군락구조(群落構造)의 각생산계층내의 균등도(均等度)가 클수록 곡실생산의 효율성이 높다는 가설(假說)을 제시(提示)하고 다수성(多收性) 및 안전성(安全性)과 관련(關聯)하여 검토(檢討)하였다. 6. 엽위별(葉位別) 엽신(葉身)의 N.P.K. 잔존률양상(殘存率樣相)이 진흥(振興)에서는 상부잔존형(上部殘存型)으로, IR667은 중앙부(中央部) 잔존형(殘存型)으로 구분(區分)되어 생산구조 보전형식(保存型式)의 원인(原因)으로 해석되었다. 7. 기관별(器管別) N.P.K 농도(濃度)와 함량분포비율(含量分布比率)에 의(依)하여 IR667은 엽초중심형으로 진흥(振興)은 엽신중심형(葉身中心型)으로 분류(分類)되었다. 8. 동일품종내(同一品種丙)에서 N.P간(間) N.P.K 각양분내(各養分內)에서 품종간(品種間) 수(穗)로의 전이율(轉移率)이 큰 경우 엽신잔존율(葉身殘存率)도 크다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1119-1120
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• 2007

Nano-sized metal patterns were successfully fabricated on flexible PET substrate using nanoimprint lithography. 70nm line and space PMMA resist pattern was formed on PET substrate without residual layer by 'artial filling effect' and 20nm thin Cr metal layer was deposited by e-beam evaporation. Then, PMMA resist was selectively removed by acetone and 70nm narrow Cr pattern was formed.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 춘계학술발표회 초록집
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• pp.24-25
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• 2007

Nano-sized metal patterns were successfully fabricated on flexible PET substrate using nanoimprint lithography. 70nm line and space PMMA resist pattern was formed on PET substrate without residual layer by "partial filling effect' and 20nm thin Cr metal layer was deposited by e-beam evaporation. Then, PMMA resist was selectively removed by acetone and 70nm narrow Cr pattern was formed.