• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.36-36
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• 2007

$R_2O_3$(R=Bi, B)-RO(R=Ba, Zn)를 주성분으로 하는 Pb-free유리프리트에 높은 굴절률을 가지고 있는 $TiO_2$ filler를 첨가하여 PDP용 백색유전체를 제조하였다. $TiO_2$ type, 함량에 따른 백색유전체로의 반사율 및 유전 특성을 조사하였다. 백색유전체를 소성한 결과 rutile과 anatase를 중량비로 75:25로 혼합하여 $520^{\circ}C$에서 소성한 경우 밀도 및 수축율의 변화를 거의 나타나지 않았다. 그러나 $TiO_2$함량이 15wt.%를 혼합하여 첨가했을 경우 반사율은 높고 접합특성 또한 우수하였다. 또한, 유전상수는 $TiO_2$첨가량이 증가함에 따라 증가하는 경향을 나타내었다.

• Journal of Mushroom
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• v.5 no.1
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• pp.34-38
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• 2007

The white-colored and the dark gray-colored mutants were frequently happened in cultivated areas of Pleurotus ostreatus (Wonhyeong-neutari). These caused conflicts between farmers and spawn companies. Our studies were conducted to elucidate the mechanism of mutagenesis. The results from the studies would provide valuable informations that could be used to prevent the color-related mutation, and also will be applied in breeding programs of P. ostreatus. Oyster mushroom variety, Wonhyeong-neutari, is somatic hybrid of Pleurotus and has genetic makers for arginine, ornithine, proline, riboflavine. Genetic markers analysis of monospore isolates derived from color mutants show identical tendency with that of Wonhyeong-neutari, these results indicate that color mutants were derived from Wonhyeongneutari. Twenty-one and four homokaryons were selected from the white-colored mutant MGL 2205 and gray-colored ASI 2029. All 34 F1 hybrids derived from the white-colored mutant MGL 2205 produce white-color fruiting bodies, indicating that the white color trait is heritable. In the first generation hybrids between the white-colored MGL 2205 and the gray-colored ASI 2029, all 16 hybrids produced pigmented fruiting bodies. Homokaryons isolated from the hybrid MGL 2205 X ASI 2029 were mated with homokaryon tester strains derived from MGL 2205. By these result, we could assumed that white color trait is a heritable character which is controlled by more than one recessive gene.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.245-250
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• 1999

Plantlets derived from leaf blade-segment culture of a variegated tobacco (Nicotiana tabacum L. cv. BY-4) that was induced by a heavy-ion ($^{14}N$) beam irradiation to proembryos, were characterized. When explants from both white and green sections of leaves of the variegated plant were cultured on MS medium containing 0.1 mg/L NAA and 1.0 mg/L BAP, the white sections yielded only white shoots, whereas the green sections generated approximately 47.2% green, 37.4% white and 15.4% variegated shoots. In the F1 generation of a green tobacco derived from the leaf blade-segment culture, the segregation ratio of green to white was 1,651:54. Furthermore, reciprocal crosses showed that all of the progenies was green, indicating that the variegation is not maternally inherited. When the signal intensity of photosynthesis genes was determined by DNA gel blot analysis using the variegated leaves derived from green sections of variegated leaves, there were more of the rbcL, psbA, 16S rDNA and 23S rDNA chloroplast genes in the white sections than the chloroplast genes in wild type and green sections of the variegated plants.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.198-198
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• 2003

LED(Light Emitting Diode)는 전기 신호를 빛으로 신호를 보내고 받는데 사용되는 반도체의 일종으로 가정용 가전제품, 리모컨, 전광판, 각종 자동화 기기등에 사용된다. 3색광 백색 LED는 soft-UV 또는 blue 빛을 내는 device 와 RGB 형광체로 이루어져 있다. 현재 연구중인 3색광 백색 LED는 InGaN 또는 GaN 이 RGB 형광체를 여기 시키는것이 대부분이다. 이러한 경우에 유기물과 무기물 형과체가 백색광을 구현하기 위해 사용된다. 유기물의 경우에는 lift-time 이 짧고, 무기물의 경우에는 유해원소인 S, Cd등이 포함되기 때문에 환경오염이 야기된다. 이러한 단점을 보완하기 위해 진화 최적방법을 이용하여 alkali earth borosilicate ((Eu,Mg,Ca,Sr,Ba)$_{x}$ $B_{y}$ S $i_{z}$ $O_{d}$ ) 계열에 $^{Eu3+}$을 도핑하여 고효율 형광체를 합성하였다.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.111-120
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• 1997

The characteristics of monosporous isolates of winter mushroom [Flammulina velutipes (Curt. ex Fr.)] were investigated to obtain useful breeding materials. Within monokaryons from cultivars which have a white colored fruitbody showed narrow genetic variation, while domestic strains which have a brown colored fruitbody showed wide variation. The mating type of the white strains was A1A2B1B2 genotype, but that of the domestic brown strains were A3A4B3B4. In intra-crossing, the genetic stability of dikaryons mated by monokaryons from white strain was less than that of parents. While in brown strain, dikaryons with high yield and color variation were obtained.

• The Korean Journal of Mycology
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• v.43 no.4
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• pp.231-238
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• 2015

Genome-wide reanalyzed data of 25 Flammulina strains were compared against the reference genome (KACC42780) to establish a genome-wide single nucleotide polymorphism (SNP). The rate of mapping differences between the strains reflected in the strain variation in its result. Genome-wide SNPs distribution divided into types of homozygous SNP and heterozygous SNP moreover all of the strains demonstrated a wide variation in all of the regions. In the further study of topological relationship between the collected strains, phylogenetic tree was separated into 3 major groups. Group I contained F. velutipes var. related strains of ASI 4062, 4148, 4195. Group 2 contained strains that are different species of ASI 4188 F. elastica, ASI 4190 F. fennae, and ASI 4194 F. rossica. The other 19 strains F. velutipes were classified as a single group. However, further experiment to discriminate its genetic relationship between the white group and brown group did not verify its validity. The inferred tree exhibited a phylogenetic relationship between Korea white fruitbody forming strains of ASI 4210, 4166, 4178 and Japan white fruitbody forming strains of ASI 4209, 4167 confirmed to be genetically closely related.

• Journal of the Korean Ceramic Society
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• v.40 no.12
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• pp.1170-1176
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• 2003

We developed an evolutionary optimization process involving a genetic algorithm and combinatorial chemistry (combi-chem), which was tailored exclusively for tile development of LED phosphors with a high luminescent efficiency, when excited by soft ultra violet irradiation. The ultimate goal of our study was to develop oxide red phosphors, which are suitable for three-band white Light Emitting Diodes (LED). To accomplish this, a computational evolutionary optimization process was adopted to screen a Eu$^{3+}$-doped alkali earth borosilicate system. The genetic algorithm is a well-known, very efficient heuristic optimization method and combi-chem is also a powerful tool for use in an actual experimental optimization process. Therefore the combination of a genetic algorithm and combi-chem would enhance the searching efficiency when applied to phosphor screening. Vertical simulations and an actual synthesis were carried out and promising red phosphors for three-band white LED applications, such as Eu$_{0.14}$Mg$_{0.18}$Ca$_{0.07}$Ba$_{0.12}$B$_{0.17}$Si$_{0.32}$O$_{\delta}$, were obtained.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.237-245
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• 1996

Esterase isozyme band patterns were compared between the wild strain and commercial strain of Flammulina velutipes. Monospores were isolated from wild strain. ASI4019 and their mating types were determined. We investigated the relationship between pigmentation on the plate and fruitbody color to understand genetic relationship among F. velutipes strains. Dikaryotic strains mated between nonpigmenting strains produced white fruitbodies. However dikaryon obtained from mating between nonpigmenting monokaryon and brown pigmenting monokaryon produced brown fruitbody as the dikaryon obtained from mating of brown pigmenting monokaryons. The white fruitbody from wild strain was distinguished from that of commercial strain. When the nonpigmenting wild monokaryon was mated with commercial monokaryon, pale brown mushroom was produced. The BC1F1 was obtained by mating the above mentioned $F_1$ with commercial monokaryon. Fruitbody color of BC1F1 shared two types; one strain with all pale brown fruitbodies, and the other strain with separated eight pale brown and two mixed type involving pale brown and white fruitbodies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.755-759
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• 2008

For the development of a new white dielectric layer in plasma display panel, different $TiO_2$ types as a filler was add to the $Bi_2O_3$-BaO-ZnO glass matrix. The reflectance and dielectric constant of dielectric have been investigated as a function of the mixing content (rutile and anatase), and sintering temperature. The reflectance of dielectric sintered at the 520$^{\circ}C$ appeared most highly and suitable in terms of the adhesion and reflectance of the soda-lime glasses. Also, the thermal expansion coefficient of dielectric was found to be $85.6\times10^{-7}/K$, which was similar to that of the soda-lime glasses. Especially, the dielectric constants were not increased with increasing of $TiO_2$ filler contents.

• Korean Journal of Optics and Photonics
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• v.4 no.4
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• pp.420-427
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• 1993

Dielectric thin film mirrors are embedded in multimode and single-mode fibers by a fusion splicing technique. The fibers with $45{\circ}$ angled embedded mirrors serve as ultra-compact directional couplers with low excess optical loss of 0.2 dB for multimode and 0.5 dB for single mode at 1.3 ${\mu}m$ and excellent mechanical properties. The reflectance is wavelength dependent and strongly polarization depencient. Far-field scans of the reflected output power measured with a white-light source show a pattern which is almost circularly symmetric with aspect ratio of 1.09 at 5% of the peak power. The splitting ratio in a multimode coupler measured with a diode laser source is much less dependent on input coupling conditions than in conventional fused biconical-taper couplers, indicating that these couplers are less susceptible to modal noise occuring in optical fiber communication systems. Spectral properties of multilayer internal mirrors normal to the fiber axis have been investigated experimentally, and a matrix analysis has been used to explain the results.