• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.291.2-291.2
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• 2013

Growth behavior of b-Ga2O3 nanowires (NWs) on sapphire(0001) substrates during radio-frequency magnetron sputtering is reported. Upon fabrication, flat thin films grew initially, subsequent to which, NW bundles were formed on the surface of thin film with increasing film thickness. This transition of the growth mode occurred only at temperatures greater than ${\sim}450^{\circ}C$. The b-Ga2O3 NWs were grown through the self-catalytic vapor-liquid-solid mechanism with self-assembled Ga seeds. Secondary growth of NWs, which occurred from the sides of primary NWs resulting in branched NW structures, was also observed. Finally, the room temperature photoluminescence properties of as-grown and annealed b-Ga2O3 NW samples were investigated.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.57-61
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• 2000

We investigated the levels of glutathione (GSH) and its oxidized form (GSSG) in 24 cell lines derived from various plant species to understand the antioxidative mechanism in plant cell cultures. The total glutathione content was 98$\pm$27 $\mu$g/g cell fresh wt, showing a slight difference in plant species. The average contort of GSH and GSSG was 72$\pm$20 and 26$\pm$10 $\mu$g/g cell fresh wt, respectively. The average GSH content in plant cell lines occupies approximately 73% in total glutathione. During the suspension cultures of Scutellaria baicalensis, one of the plant species we tested, the GSH content decreased in proportion to the cell growth during the exponential growth stage, showing the low level at the stationary growth stage (84 $\mu$g/g cell fresh wt), whereas the GSSG content increased to the stationary growth stage (31 $\mu$g/g cell fresh wt). The results suggested that the ratio of GSH and GSSG should be involved in the cell growth and antioxidative mechanism in cultured cells.

• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.83-87
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• 2008

Tension wood, a specialized tissue developed in the upper side of the leaning stem and drooping branches of angiosperm, is an attractive experimental system attractive for exploring the development and the biochemical pathways of the secondary cell wall formation, as well as the control mechanism of the carbon flux into lignin, cellulose, and hemicellulose. However, the mechanism underlying the induction and the development of the tension wood is largely unknown. Recently, several researchers suggested the possible roles of the plant growth hormones including auxin, gibberellin, and ethylene mainly based on the expression pattern of the genes in this specialized tissue. In addition, expressed sequence tag of Poplar and Eucalyptus provide global view of the genetic control underlying the tension wood formation. However, the roles of the majority of the identified genes have not yet been clearly elucidated. The present review summarized current knowledge on the biosynthesis of tension wood to provide a brief synopsis of the molecular mechanism underlying the development of the tension wood.

• Journal of Korea Technology Innovation Society
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• v.3 no.2
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• pp.94-110
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• 2000

This article prospects the patterns of technological innovation in the steel industry and suggests the directions of technological innovation in Korean steel industry. Technological innovation patterns can be analysed through technological trends, innovation-inducing mechanism, and innovators' relationships. In the technological trends, direct coupling of manufacturing processes, lasting growth of mini-mill, and the importance of technological integration are prospected. In the innovation-inducing mechanism, while production system will be specialized, the development of new steel materials and environment-friendly technological innovation will be accelerated. In the innovators' relationships, steel industry faces more complex competition and new forms of inter-firm cooperation including M&A, joint venture, and joint R&D. In order to cope with such changes in the technological innovation patterns, Korean steel industry need to establish core competence based on technological innovation through a great leap in R&D investment, the production of high value-added products, the development of new generation steel technologies, strategic joint R&D, comprehensive technological cooperation, and government's active support.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.655-661
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• 1999

${\beta}$-SiC formation mechanism in Si melt-C-SiC system with varying in size of carbon source was investigated. A continuous reaction sintering process using Si melt infiltration method was adopted to control the reaction sintering time effectively. It was found that ${\beta}$-SiC formation mechanism in Si melt-C-SiC system was directly affected by the size of carbon source. In the Si melt-C-SiC system with large carbon source ${\beta}$-SiC formation mechanism could be divided into two stages depending on the reaction sintering time: in early stage of reaction sintering carbon dissolution in Si melt and precipitation of ${\beta}$-SiC was occurred preferentially and then SIC nucleation and growth was controlled by diffusion of carbon throughy the ${\beta}$-SiC layer formed on graphite particle. Furthmore a dissolution rate of graphite particles in Si melt could be accelerated by the infiltration of Si melt through basal plane of graphite crystalline.

• Journal of Information Processing Systems
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• v.6 no.1
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• pp.107-120
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• 2010

The Internet has been growing at unprecedented rates. The problem of an address shortage could act as a barrier on this growth. In principle, a new Internet standard, IPv6 solves the problem of the address shortage because it has a very large address space. But IPv6 is not yet compatible with the IPv4 and during the IPv4-to-IPv6 transition period IPv4 address will continue to be in demand. Thus for quite some time, the problem of IP address shortage will persist. To solve the problem, we propose the mechanism of secure IP address trading. This mechanism is based on the Resource PKI (RPKI). The RPKI is the working item of IETF. This proposed mechanism maximizes the trust of IP address trading using RPKI.

• Development and Reproduction
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• v.4 no.2
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• pp.137-145
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• 2000

The regulatory mechanisms of the initiation and the formation of ovarian follicles during fetal stage of mammals are largely unknown. In addition to the gonadotropins secreted from pituitary, various growth factors, and steroid hormones are believed to be involved in the differentiation and initiation of growth of primordial follicles consisting of primordial germ cells migrated from yolk sac and streamed cells from mesonephric somatic cells. In human, primordial follicles that have already initiated differentiation at fetal stage undergo either folliculogenesis to ovulate or atresia after growth. Some of primordial follicles remain without growth for 50 years or longer. The objective of this paper is to review the mechanism of the formation, growth arrest, and initiation of primordial follicles in human fetal and neonatal ovaries.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.398-404
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• 2003

Most previous researches for the hybrid composite materials such as FRMLs(Al/AFRP, Al/GFRP) have evaluated the fatigue delamination behavior using the traditional fracture mechanism. However, most previous researches have not generally been firmed yet. Because delamination growth behavior in hybrid composite should be consider delamination growth rate, $dA_D$/da using the delamination shape factors, fs instead of traditional fracture mechanic parameters. The major purpose of this study was to evaluate the relationship between delamination shape factor, fs and delamination growth rate, $dA_D$ . And a propose parameter on the delamination aspect ratio, b/a. The details of the study are as follow : 1) Relationship between crack length, a and delamination width,b. 2) Relationship between delamination aspect ration, b/a and delamination area rate,($(A_D)_{N}(A_D)_{ALL}$. 3) Variation of delamination growth rate, $dA_D/da$ was attendant on delamination shape factors, $fs_1$, $fs_2$, $fs_3$. The test results indicated the delamination growth rate depends on delamination shape factors.

• Journal of The Korean Association For Science Education
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• v.13 no.3
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• pp.327-333
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• 1993

The purpose of this study was to investigate children's ideas about growth of plants and their conceptural change after instruction to apply SPACE (Science Processes And Concepts Exploration) Learning strategy. For this study, a total of 55 students from infants to 5th grade were sampled. Data were obtained by the individual interview procedure and summarized by using network analysis. The major results of this study were as follows : 1. A very small number of students responded reforming or reorganisation of materials about the mechanism of germination and growth inside the seeds. 2. Almost all students confused between conditions necessary for germination and growth. Water and sunlight were mentioned by many students, while air and temperature were mentioned by a few students as the condition. 3. Some of the students showed that growth occurs continuously. Many students explaned occurence of growth about Plants related to the night, monning, or evening. 4. With the explaning about the necessary conditions for caterpillar growth, students mentioned conditions related in terms of human experience. 5. Many young childrens showed tendency of the egocentric and human-centered view of the world. Students scientific concepts increased significantly with age. Many students conceptions depend on the context-specificity ideas.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.44-44
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• 2003

Growth mechanism of carbon nanotubes(CNTs) synthesized by chemical vapor deposition is abided by two growth modes. These growth modes are classified by the position of activated catalytic metal particle in the CNTs. Growth mode can be also affected by interaction between substrate and catalytic metal and induced energy such as thermal and plasma. We studied the reaction of catalytic metal to the substrate and growth mode of CNTs. Various substrates such as Si(100), graphite plate, coming glass, sapphire and AAO membrane are used to study the relation between catalytic metal and substrate in the synthesis of CNTs. For catalytic metal, thin film was deposited on various substrate via sputtering technique with a thickness of ∼20nm and magnetic fluids with none-sized particles were dispersed on AAO membrane. After laying process on AAO membrane, it was dried at 80$^{\circ}C$ for 8 hour. Synthesizing of CNTs was carried out at 900$^{\circ}C$ in NH3/C2H2 mixture gases flow for 10minutes.