• 한국진공학회지
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• 제6권1호
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• pp.1-8
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• 1997

SUS 316 합금의 노출 조건에 따른 오염 과정과 구조를 x-ray photoelectron spectroscopy실험을 통해 보았다. SUS표면에 부착된 오염 물질은 주로 metal-oxide, metal-H-oxide, CO, COH, 그리고 CxHy임을 보았다. 오염 물질의 층별 형성 구조는 $C_xH_y$/CO(COH)/metal-H-oxide/metal-oxide가 SUS합금 위에 있는 형태이다. 오염 과정은 주로 금속 구성물의 산화와 $C_xH_y$의 흡착과정 두 가지에 의해서 이루어지는 것을 볼 수 있 었다. 초고진공 환경에서는, 오염은 주로 산화층 형성에 의한 것으로 노출 시간이 증가함에 따라 산화층의 두께가 계속 증가하였다. 고진공 또는 높은 압력 환경에서는 노출 초기에 대 부분의 산화층이 형성되고, 노출 시간의 증가에 대해서는 주로 $C_xH_y$에 의한 오염이 계속 증 가하였다. 스테인레스 표면 안에 깊이 분포하고 있는 metal-oxide의 농도는 지수형으로 감 소하는 형태의 분포를 가지며 그 두께는 대기 노출된 시료의 경우 광전자의 평균자유행로 규모로 형성되는 것을 보았고, 특히 Fe-oside가 Cr-oxide를 덮고 있는 표면 편석 현상이 보 였다.

• Journal of Welding and Joining
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• 제34권1호
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• pp.75-81
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• 2016

This study applied laser surface melting process using CW(Continuous wave) Yb:YAG laser and cold-work die steel SM45C and investigated microstructure and hardness. Laser beam speed, power and beam interval are fixed at 70 mm/sec, 2.8 kW and $800{\mu}m$ respectively. Depth of Hardening layer(Melting zone) was a minimum of 0.8 mm and a maximum of 1.0 mm that exceeds the limit of minimum depth 0.5 mm applying trimming die. In all weld zone, macrostructure was dendrite structure. At the dendrite boundary, Mn, Al, S and O was segregated and MnS and Al oxide existed. However, this inclusion didn't observe in the heat-affected zone (HAZ). As a result of interpreting phase transformation of binary diagram, MnS crystallizes from liquid. Also, it estimated that Al oxide forms by reacting with oxygen in the atmosphere. The hardness of the melting zone was from 650 Hv to 660 Hv regardless of the location that higher 60 Hv than the hardness of the HAZ that had maximum 600 Hv. In comparison with the size of microstructure using electron backscatter diffraction(EBSD), the size of microstructure in the melting zone was smaller than HAZ. Because it estimated that cooling rate of laser surface melting process is faster than water quenching.

• 한국가스학회지
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• 제24권5호
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• pp.39-46
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• 2020

본 논문에서는 파이프라인에서 사용되는 API 5L 철강의 중심선 편석에 대해 다루고자 한다. Mn/S와 Nb 그리고 C는 파이프 두께 방향으로의 중심선에서 편석되는 요소로 알려져 있다. Mn은 일반적으로 긴 점성상을 이루는 S를 동반한다. 중심선의 미세조직은 MnS와 산소를 포함한 Nb/Ti로 구성되어 있는데 이 중심선 지역의 편석효과를 OM, SEM/EDS 및 마이크로비커스 경도기로 분석하였다. Mn, Nb 및 C는 오스테나이트가 페라이트 또는 마르텐사이트로 변태하는 것을 억제시키는 원소이다. 이러한 원소들은 마르텐사이트의 한 종류인 베이나이트 미세조직을 만들 수 있는데 이는 용융 및 열처리에서 얻어지는 중심선과 매트릭스 간의 원소 편석과는 다르다.

• Journal of Ginseng Research
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• 제35권4호
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• pp.399-412
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• 2011

Little is known about the genetics or genomics of Panax ginseng. In this study, we developed 70 expressed sequence tagderived polymorphic simple sequence repeat markers by trials of 140 primer pairs. All of the 70 markers showed reproducible polymorphism among four Panax species and 19 of them were polymorphic in six P. ginseng cultivars. These markers segregated 1:2:1 manner of Mendelian inheritance in an $F_2$ population of a cross between two P. ginseng cultivars, 'Yunpoong' and 'Chunpoong', indicating that these are reproducible and inheritable mappable markers. A phylogenetic analysis using the genotype data showed three distinctive groups: a P. ginseng-P. japonicus clade, P. notoginseng and P. quinquefolius, with similarity coefficients of 0.70. P. japonicus was intermingled with P. ginseng cultivars, indicating that both species have similar genetic backgrounds. P. ginseng cultivars were subdivided into three minor groups: an independent cultivar 'Chunpoong', a subgroup with three accessions including two cultivars, 'Gumpoong' and 'Yunpoong' and one landrace 'Hwangsook' and another subgroup with two accessions including one cultivar, 'Gopoong' and one landrace 'Jakyung'. Each primer pair produced 1 to 4 bands, indicating that the ginseng genome has a highly replicated paleopolyploid genome structure.

• 교육시설 논문지
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• 제22권3호
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• pp.21-29
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• 2015

Jinhae's educational facilities had been located in the most integrated area at the beginning. As Jinhae's spatial layout has been in a rapid growth by constructing new towns and experiencing major consolidations over years, it was argued that this morphological transformation inevitably brought to the change of the characteristics of educational facilities' arrangement. In this reason, a number of studies have discussed the ways of how they have been settled down from the beginning of Jinhae. However, they did not take into an account of both the first consolidation happened in 1985 and the second one in 2013. This paper therefore aims to investigate how Jinhae's urban structure has been transformed between the two consolidations from a syntactical perspective, and then to interpret characteristics of educational facilities arrangement accordingly. This study finds out that when Jinhae experienced the first consolidation, educational facilities were occupied in highly segregated areas in terms of both global and local integration values. However, their locations turned out to be more intelligible after the second consolidation. This suggests that they have a significant effect on the process of urban growth at local level. Although the educational facilities particularly in Pungho and Ungchun are in highly integrated spaces at global level, they are still less intelligible.

• 한국재료학회지
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• 제23권11호
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• pp.649-654
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• 2013

The effect of interstitial elements on the ductile-brittle transition behavior of austenitic Fe-18Cr-10Mn-2Ni alloys with different nitrogen and carbon contents was investigated in this study. All the alloys exhibited ductile-brittle transition behavior because of unusual low-temperature brittle fracture, even though they have a faced-centered cubic structure. With the same interstitial content, the combined addition of nitrogen and carbon, compared to the sole addition of nitrogen, improved the low-temperature toughness and thus decreased the ductile-brittle transition temperature (DBTT) because this combined addition effectively enhances the metallic component of the interatomic bonds and is accompanied by good plasticity and toughness due to the increased free electron concentration. The increase in carbon content or of the carbon-to-nitrogen ratio, however, could increase the DBTT since either of these causes the occurrence of intergranular fracture that lead to the deterioration of the toughness at low temperatures. The secondary ion mass spectroscopy analysis results for the observation of carbon and nitrogen distributions confirms that the carbon and nitrogen atoms were significantly segregated to the austenite grain boundaries and then caused grain boundary embrittlement. In order to successfully develop austenitic Fe-Cr-Mn alloys for low-temperature application, therefore, more systematic study is required to determine the optimum content and ratio of carbon and nitrogen in terms of free electron concentration and grain boundary embrittlement.

• 건축역사연구
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• 제20권1호
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• pp.77-93
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• 2011

Across the culture of Western Europe, dichotomy based on the visual sense has evolved. They believed eyes and ears requiring a distance related in recognition, are more developed than any other human senses in human body. Dominant position, as a condition to using a perspective, the eye has been just concentrated in the development of optical sight. But developed a variety of modern media, highlighting the importance of the other perception, it makes dichotomy to the expansion of perception over the single function of visuality. Recently, Guille Deleuze and Merleau-Ponty try to recover the sense of tactility segregated in skin from body keeping eyes for distance. By the result, the activity can be happened by being connected to the body rather than to eye in the space between the subject and object. From the phase of recognition where the human body tries to identify the object in the space considering a time, it will be changed for the subject to the phase of structure vice versa. Visual tactility is to eliminate the distance between subject and object. If the visual tactility is to erase the distance different from the visual in dichotomy, it will be occurred to having a tension and makes new relationship to work trying to move the subjective point of view in object. Like this evidence in analysis of architecture, it can be easy to find the Korean architecture rather than western architecture in terms of emphasizing the time and space. The fact, architecture of Lee Dynasty had been preserved and consisted basic form and style over the centuries makes us assume that visual tactility was considered as well as the visual sense. This study will be intensive in terms of visual and tactile inherent in the subject and how it is being connected to the movement in the space and time.

• 한국실내디자인학회논문집
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• 제25권3호
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• pp.11-20
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• 2016

The aim of this study is to analyze the organization of ithe internal space of Usonian houses that were designed by Frank Lloyd Wright between the 1930s and the 1950s. The Space Syntax Program was used to analyze spatial structure of these Usonian houses. The research range has been done on 9 case studies of Usonian house floor plans, which were designed from the 1930s to the 1950s. The shape of unit floor plans of Usonian house are usually in various L types, - types and transformed types etc.. The research results are as follows : 1) The service space(Kitchen etc.)is located at the center of house and it plays a role in separating the private space(bedroom etc.) and public space(living room etc.). 2) All of the bedrooms of Usonian houses have common characteristic : they are connected by a galley(corridor). 3) The organization of the inside space of most of these houses showed a tendency segregation space. 4) The galley inside space of Usonian house is the most integrated space in the house 5) The living room of the 1930s houses was analyzed as segregation space but it of 1940s and 1950s houses was analyzed as integration space 6) Although bedrooms are connected by galley, which is the highest integrated space of the inside space, this space is analyzed as a segregated space.

• Current Research on Agriculture and Life Sciences
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• 제2권
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• pp.42-55
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• 1984

The direction of scientific researches on tree improvement and forest management in several universities and research institutes in Japan can be summarized as follows: They put a great emphasis on sugi, Cryptomeria japonica and cypress, Chamaecyparus oblusa which are two major conifer species largerly planted in the Japanese forestry. In the research of sugi, a great concern has been made in evaluating inheritance of forest tree, quantitative characters and genetic parameter of growth, and in breeding for resistance to diseases and insects and to all the natural calamities. Interaction between environmental conditions and genetic nature of tree can be concerned factors in relation with forest damage, together with silvicultural conditions and pest infestation. Selfing hybrids of $F_1$ made from crossing twisted-leaf sugi, defomity leaf type and midori sugi, normal leaf type segregated the normal needle, twisted needle, green leaf and albino leaf type. It seemed that separation of many defomity individuals can be governed by two dominant complementary genes and from the near loci of which it was detected lethal genes. 52% of Japanese forestry is occupied by the small forest landowners like Korean forestry. This made difficulty for forest improvement such as progressive afforestation and for capital accumulation form forestry. The Forest Corporation was established at first in 1959 to aming at productive forestry structure and forest management, and afforestation. For these purpose, 35 Forest Corporations are at moment operating throughout Japan. However, investment in forestry business becomes less attractive since the wage in forest production duction increased in higher trend. than timber price. Therefore, an artifical afforestation becomes yearly decreased. At present. the self-sufficient rate of timber production in Japan is about 35%, and so a great effort is being made to increase self-sufficient rate of timber production.

• 대한금속재료학회지
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• 제47권7호
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• pp.440-446
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• 2009

Co base superalloys have been widely used for the parts of gas turbine due to their excellent strength, thermal fatigue, oxidation resistance and weldability at high temperature. In this study, directional solidifications were carried out at various solidification rates, including $0.5{\sim}300{\mu}m/s$ in the Co base superalloy FSX-414. The cellular interface were formed at a low solidification rate, $1{\mu}m/s$, and the dendritic interface was found at higher solidification rates, $5{\sim}300{\mu}m/s$. As the spacing of dendrite structure decreased, the size and spacing of eutectics decreased. Dendrite arm spacing decreased with increasing solidification rates and temperature gradient. It was interesting to find the $M_{23}C_{6}$ eutectic microstructure formed between $\gamma$ dendrites. Composition analysis showed that Cr and W were segregated severely between the dendrites, which resulted in the formation of Cr-rich $M_{23}C_{6}$ and W-rich MC carbides.