• 식물조직배양학회지
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• 제28권3호
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• pp.147-151
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• 2001

Explants of Lactuce sativa cultivar, chungchima, were co-cultivated with Agrobacterium tumefaciences LBA4404, EHA101 strains containing nptll gene and ferritin gene encoding iron storage protein from soybean for transformation. Through initial selection of regenerated explants by culturing on a kanamycin and carbenicillin containing MS medium, multiple shoots were obtained after 2 months of culture. For a complementary step of selection, putative transgenic shoots were transferred to 1/2 MS basal medium supplemented with 100 mg/L kanamycin and 500 mg/L carbenicillin. The selected shoots were tested with PCR analysis using nptll, ferritin specific primers whether ferritin gene was introduced to genome of the plants. These results confirmed that produced the specific PCR bands in the putative transgenic lines. Additionally the Northern blot showed that transcripts of ferritin gene were detected in mature leaf of the transgenic lines. These results suggest that ferritin gene be successfully integrated and transcribed in the putative transgenic lettuce plants.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 춘계학술발표논문집 1부
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• pp.257-260
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• 2010

In this paper, we propose the computation reduction methods of LSP(Line spectrum pairs) transformation that is mainly used in CELP vocoders. In order to decrease the computational time in real root method the characteristic of four proposed algorithms is as the following. First, scheme to reduce the LSP transformation time uses mel scale. Developed the second scheme is the control of searching order by the distribution characteristic of LSP parameters. Third, scheme to reduce the LSP transformation time uses voice characteristics. Developed the fourth scheme is the control of searching interval and order by the distribution characteristic of LSP parameters. As a result of searching time, computational amount, transformed LSP parameters, SNR, MOS test, waveform of synthesized speech, spectrogram analysis, searching time is reduced about 37.5%, 46.21%, 46.3%, 51.29% in average, computational amount is reduced about 44.76%, 49.44%, 47.03%, 57.40%. But the transformed LSP parameters of the proposed methods were the same as those of real root method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.465-469
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• 1997

In this paper, shape memory compsites are made by powder metallurgy. And then, an self-strengthening effect of the composites by shape memory effect above inverse transformation temperature A/sab f/ of TiNi alloy discussed. Moreover, TiNiCo/Al composite is made by using TiNiCo alloy as fiber. And it is discused aboutaffection of Co in the shape memory composite. The results of the intelligent properties of TiNi/Ai-radical shape memory composite, using SMA, by powder metallurgy are the tensile strength of TiNiCo wire is much higher than that of TiNi wire. and the strength of TiNiCo/Al composite is generally higher than that TiNi/Al composite.

• Journal of Ginseng Research
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• 제27권1호
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• pp.17-23
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• 2003

Agrobacterium-mediated transformation of American ginseng (Panax quinquefolius L.) with strain LBA 4404 containing a rice thaumatin-like protein gene is described. The selectable markers used were phosphinothricin acetyltransferase and hygromycin phosphotransferase genes. Epicotyl explants from seedlings were precultured for 5-7 days on Murashige and Skoog medium with ${\alpha}$-naphthaleneacetic acid and 2,4 dichlorophenoxyacetic acid at 10 ${\mu}$M and 9 ${\mu}$M, respectively (ND medium), prior to Agrobacterium infection. The explants were immersed in a bacterial suspension for 20 min. A post-infection co-culture period of 3-4 days was provided on ND medium. Selection for transformed calli was conducted on ND medium with 20 mg/L phosphinothricin followed by 100 mg/L hygromycin over an 8-month period. it transformation frequency of 24.8% was achieved at the callusing phase. The presence of the transgenes in calli was confirmed by Southern hybridization and polymerase chain reaction analysis. The expression of the thaumatin-like protein gene in ginseng calli was demonstrated by Western blot analysis. Somatic embryos were produced from both transgenic calli and suspension cultures, and plantlets were recovered that expressed the transgenic thaumatin-like protein gene.

• Journal of Plant Biotechnology
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• 제39권1호
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• pp.13-22
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• 2012

Plant regeneration has been optimized increasingly by organogenesis and somatic embryogenesis using a range of explants with tissue culture improvements focusing on factors, such as the age of the explant, genotype, media supplements and $Agrobacterium$ co-cultivation. The production of haploids and doubled haploids using microspores has accelerated the production of homozygous lines in Brassicaceae crop plants. Somatic cell fusion has facilitated the development of interspecific and intergeneric hybrids in sexually incompatible species of $Brassica$. Crop improvement using somaclonal variation has also been achieved. Transformation technologies are being exploited routinely to elucidate the gene function and contribute to the development of novel enhanced crops. The $Agrobacterium$-mediated transformation is the most widely used approach for the introduction of transgenes into Brassicaceae, and $in$ $vitro$ regeneration is a key factor in developing an efficient transformation method in plants. Although many other Brassicaceae are used as model species for improving plant regeneration and transformation systems, this paper focuses on the recent technologies used to regenerate the most important Brassicaceae crop plants.

• 한국재료학회지
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• 제12권4호
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• pp.308-316
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• 2002

The cavitation erosion behavior of wear-resistant hardfacing alloys such as Co-base Stellite 6, Fe-base Norem 02 and new Fe-base alloy were investigated up to 50 hours by using a 20kHz vibratory cavitation erosion test equipment. The crack, initiated easily at the interfaces between matrix and hard second phase, was repressed effectively in Stellite 6 because the matrix was hardened by phase transformation. For this reason, Stellite 6 showed an excellent cavitation erosion resistance compared to Norem 02. The phase transformation also occurred in Norem 02, but the increase of volume fraction of the interfaces caused the crack to be initiated frequently, thus resulting in a 1arge material loss. The matrix of NewAlloy was hardened effectively by vlongrightarrow$\alpha$' phase transformation and the volume fraction of the interfaces was very small compared to Norem 02. This caused the propagation of crack to the matrix to be repressed effectively. Therefore, NewAlloy showed a very excellent cavitation erosion resistance. It wasn't considered that the cavitation erosion resistance of NewAlloy was influenced the temperature of the bath filled with a distilled water up to $80^{\circ}C$.

• 대한금속재료학회지
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• 제49권1호
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• pp.46-51
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• 2011

Real-time formation of $L1_0$ phase of FePt nanoparticles in the gas phase during ultrasonic-spray pyrolysis is first discussed in the present study. Without any post heat treatment, $L1_0$ phase of FePt nanoparticles appeared at the temperature above $900^{\circ}C$ in the gas phase synthesis. X-ray diffractometry (XRD) and transmission electron microscopy (TEM) studies revealed that FePt nanoparticles less than 10 nm in size contained small volume of $L1_0$ fct phase. However, in other samples obtained at the temperature below $900^{\circ}C$, iron oxide phase co-existed and no evidence of phase transformation was found. Thus, it is anticipated that the time of flight of particles required for crystallization and phase transformation was extended according to the increase of the collision rate. Finally, magnetic properties represented by coercivity and saturation magnetization and functional groups on the particle surface were discussed based on VSM and FT-IR results.

• 대한치과기공학회지
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• 제37권4호
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• pp.235-242
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• 2015

Purpose: The aims of this study are compare with microstructure and mechanical properties of Co-Cr-Mo alloys fabricated by powder metallurgy(P/M) process and casting process respectively. Methods: Microstructure and micro-hardness were tested by SEM and Vickers Hardness Tester. The sintered specimen was produced by furnace-coolling after sintering, however the casting specimen were produced thru air-cooling and water-cooling after the casting. For observation of phase transformation during sintering, DSC analyzing was carried out. Results: Mean pore size of sintered Co-Cr-Mo alloy was $4.32{\mu}m$ and that of casting alloy was $1.63{\mu}m$. Hardness of sintered alloy was lower than water-quenched casting alloy. Conclusion: Proper sintering temperature of Co-Cr-Mo alloy was above $1,200^{\circ}C$ and pore size of casting specimen were finer than sintered specimen, but hardness were similar.

• 한국유통학회지:유통연구
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• 제7권1호
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• pp.105-127
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• 2002

본 연구는 마케팅 믹스의 사이버 전환 문제에 집중하여, 온라인 쇼핑몰을 조사표본으로 선정하고 실증 분석한 연구이다. 웹사이트에 나타난 기업특징, 웹사이트 기본기술, 커뮤니티 기술을 측정하여, 이들이 마케팅 믹스의 사이버 전환에 어떻게 영향을 미치는지 규명하였다. 실증분석 결과, 마케팅 믹스의 사이버 전환 수준은 웹사이트 기술의 영향을 받는다는 것이 검증되었다. 웹사이트 평가의 조사문항으로는 웹사이트에서의 기업특징 5항목, 웹사이트 기본기술 10항목, 커뮤니티 기술 12항목을 5점 척도로 하여, 국내 100hot.co.kr의 식품, 화장품, 보석/액세서리 3업종 123개 쇼핑몰 웹사이트를 대상으로 패널조사 하였다. 분석결과 원인변수는 기술, 상호작용, 연결, 기업특성, 도메인의 5개 요인으로 추출되었다. 연구결과는 두 가지로 요약할 수 있다. 첫째, 웹사이트에 나타난 기업특징, 웹사이트 기본기술 요소, 커뮤니티 기술 요소에서 상호 공통성이 있는 요소의 결합을 규명하였다. 즉, 기술, 상호작용, 연결, 기업특성, 도메인 요인이 추출되었다 둘째, 추출된 요인이 마케팅 믹스가 사이버 전환에 어느 정도 영향을 미치는지 검증하였다. 즉, 기술 요인과 상호작용 요인은 마케팅 4P 믹스 모두와 유의한 상관이 있는 것으로 밝혀졌다. 특히 유통믹스의 영향이 가장 높은 것으로 나타났다. 사이버 공간의 새로운 비즈니스 모델에서는 전통적인 4P 믹스를 적절히 전환하고, 고객관계 증진, 공유적 시장공간 창출, 상호연결에 초점을 두어야 할 것이며, 새로운 경영환경에서는 상호작용성과 연결성이 어떻게 활용되느냐에 따라 마케팅 성과가 달라질 것이다.

• 한국재료학회지
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• 제15권10호
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• pp.667-670
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• 2005

Binary skutterudite $CoSb_3$ compounds were prepared by the arc melting and hot pressing processes and their thermoelectric properties were investigated in the range from 300 to 600 K. Annealing effect was correlated to phase transformation and homogenization. Thermoelectric properties of the arc-melted and hot-pressed $CoSb_3$ were discussed and compared. Undoped intrinsic $CoSb_3$ prepared by the arc melting showed p-type conduction, while it showed metallic behavior with increasing measuring temperature. However, hot pressed specimens showed n-type conduction, possibly due to Sb evaporation. Thermoelectric properties were remarkably improved by annealing In vacuum and they were closely related to phase transformation.