• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1159-1161
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• 1993

This paper may be presented the carrier oscillation properties for the varistor fabricated by a new method of three-composition seed grain, in order to analyze the behavior of carriers at the its equivalent circuit model. The oscillation phenomena of carriers appeared from current-voltage characteristics under knee voltage is shown by the transient flow of non trapped carriers group in the trap level of intergranular layer, surface state and/or depletion layer. However, Current oscillation phenomena is hardly shown in the high electric field. The injected carriers from both electrodes are directly flowed from the conduction band of forward biased grain through the intergranular layer into the reverse biased grain, because the trap level in the electric field above the knee voltage is mostly filled.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.32-37
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• 1994

This experiment was conducted to obtain the basic information for the increase ofgermination percent by the seed diameter, specific gravity, different grain filling period and stratification in Bupleurum falcatum seeds. The seed size of B.falcatum ranged from 2.0 to 3.9mm in diameter, The large seed showed the higher germinability, The optimum specific gravity of salt selection for seed screening was 1.05 resulting in screening out seeds with high germinability over 70%.The seeds needed grain filling period for 60 days or longer after flowering to keep high germinability The optimum period of stratification treatment to promote seed germination was about 80 days.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.293-297
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• 2000

Multiseeding with (100)/(100) grain junctions of top-seeded melt growth (TSMG) processed YBCO superconductors was studied. The effect of the number of seeds and the distance between two seeds on the levitation forces and the trapped magnetic fields of the TSMG-processed YBCO samples was investigated. Multiple seeding shortened the processing time for the fabrication of TSMC-processed YBCO superconductors. The large magnetic field was trapped at the grain junction when two seeds was placed without spacing, while the amount of the magnetic field decreased when the seed distance increased. This is attributed to the increased amount of the residual melt phases around the grain junctions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.4
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• pp.245-250
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• 2000

This study was conducted to analyze the responses of some agronomic traits to the different cultural environments and relations among the agronomic traits for selecting sesame varieties with higher cultural stabilities. The indexes for stability parameters measured were coefficient of variability, heritabilities, genetic correlations and path coefficients of agronomic traits according to locations and years in Korea. The heritabilities of agronomic traits showed different by locations and years. Number of seeds per capsule and 1000 seeds weight showed higher heritabilities, but stem length and seed weight per plant showed relatively lower heritabilities. Average heritabilities of some agronomic traits in 1998 were comparatively higher than those of 1999. Of six areas, Jinju area showed biggest coefficient of yield variability in 1998-1999. Iksan and Taegu areas showed higher heritabilities in 1998, but Iksan and Jinju areas showed lower heritabilities in 1999. Genetic correlations were slightly higher than corresponding phenotypic correlations. Stem length showed positive genetic correlation with the number of capsules per plant, and seed weight per plant and the number of capsule per plant showed positive genetic correlation with seed weight per plant. On the analysis of path coefficients, stem length and number of capsules effected highly on grain yield. Great regional variations were observed on the effects of agronomic traits on grain yield. Higher direct effects of stem length on grain yield were observed at Suwon, Chungwon, Taegu, Jinju and Naju areas, but in Iksan area was observed higher direct effect of the number of capsules per plant on grain yield in 1998. In 1999, higher direct effect of stem length on grain yield was observed at Chungwon and Suwon areas. Iksan and Taegu areas were also observed higher direct effect of the number of capsule per plant on grain yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.429-433
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• 2001

This study was carried out to investigate the occurrence and characteristics of off-type rice plant according to agronomic conditions. The occurrence density of the off-type rice plant in farmer's paddy field was greater as the years of self-produced seed use increased, and in the direct sowing paddy field it was twice as much as in the transplanting paddy field. When the long-grain red rice and the short-grain red rice in the cultivated field of cultivar were artificially sown, in the direct sowing on a flooded paddy surface culture rather than in the machine transplanting culture the off-type rice plant occurred much more, the culm length was longer, and the number of productive culm per plant increased. These characteristics were more conspicuous in the long-grain red rice than in the short-grain red rice. In the transplanting farmer's paddy fields, the off-type rice plant that occurred outside of the hills of the cultivar rice ranged 0 to 6%. Whereas in was 70.6 to 91.9% when the long-grain red rice and short-grain red rice were artificially sown. Therefore, it was assumed that most of the off-type rice plants occurred in the farmer's paddy fields was caused by seed contamination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.211-215
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• 1983

Thirty eight varieties with high uniformity and clearance in grain quality among 70 colored soybeans collected from nation-wide provinces were investigated for their seed morphological and agronomic traits. As for seed morphological traits, grain volumetric size, grain weight, grain length, grain thickness, . hilum length and width were studied on the tendency of statistical dispersion and variations. As a result, four groups could be classified on the basis of 100 grains weight, so as small, medium, large, and super large groups, Also, as for agronomic traits, among others, the tendency of setting in flowering date, maturing date, yield components, and stem weight, stem length were studied on the basis of statistical inter-relationships between above mentioned characteristics. From the above, bigger variations were detected in weighing characters of soybean plants than in duration characters. And the flowering and maturing days showed significant relationships to the stem length, stem weight, also stem length and stem weight to the grain yield.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.119.2-120
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• 2003

Seed-borne fungal pathogens on rice seeds were investigated in order to evaluate their effect on rice grain quality. Rice seeds of two cultivars, Ilmibyeo and Daesanbyeo were collected from 27 areas of Korea and the fungal parasites on seeds were isolated by using a blotter method. Isolation frequency and number of species were varied from collection areas of seed samples. A total 13 species of fungi were identified from the seeds. Among them, Altemana alternata was the most frequent over the country. Bipoiaris oryzae most commonly from Gyeongbuk and Jeonbuk, Alternaria padwickii from Jeonbuk, and Nigrospora oryzae from Choongnam. However Bipolaris. oryzae, Alternaria padwickii, and Nigrospora oryzae were the most frequently isolated fungi from Gyeongbuk and Jeonbuk, and Chungnam, respectively. B. oryzae, A. alternata, A. padwickii, and N. oryzae were dominants on Ilmibyeo showing 10.3％, 10.2％, 5.2％, and 5.2％ infection rate, respectively. While, N. oryzae, A alternata, and Cladosporium sp. were most frequently isolated fungi from Deasanbyeo revealing 15.1％, 9.6％, and 7.5％ infection rate, respectively. These fungi inhabiting on hulls or endosperms of rice seed might be considered as potential factors decreasing rice grain quality. Further investigation of the fungi on grain rice quality are undergoing.

• Journal of Powder Materials
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• v.17 no.1
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• pp.13-22
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• 2010

The unique features of spark plasma sintering process are the possibilities of a very fast heating rate and a short holding time to obtain fully dense materials. $\beta$-SiC powder with 0, 2, 6, 10 wt% of $\alpha$-SiC particles (seeds) and 4 wt% of Al-B-C (sintering aids) were spark plasma sintered at $1700-1850^{\circ}C$ for 10 min. The heating rate, applied pressure and sintering atmosphere were kept at $100^{\circ}C/min$, 40 MPa and a flowing Ar gas (500 CC/min). Microstructural development of SiC as function of seed content and temperature during spark plasma sintering was investigated quantitatively and statistically using image analysis. Quantitative image analyses on the sintered SiC ceramics were conducted on the grain size, aspect ratio and grain size distribution of SiC. The microstructure of SiC sintered up to $1700^{\circ}C$ consisted of equiaxed grains. In contrast, the growth of large elongated SiC grains in small matrix grains was shown in sintered bodies at $1750^{\circ}C$ and the plate-like grains interlocking microstructure had been developed by increasing sintering temperature. The introduction of $\alpha$-SiC seeds into $\beta$-SiC accelerated the grain growth of elongated grains during sintering, resulting in the plate-like grains interlocking microstructure. In the $\alpha$-SiC seeds added in $\beta$-SiC, the rate of grain growth decreased with $\alpha$-SiC seed content, however, bulk density and aspect ratio of grains in sintered body increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.427-434
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• 2014

This study aimed to investigate the effects of pre-harvest sprouting (PHS)-damaged grains of rice on seed viability, germination percentage and seedling emergence rate. As comparing the seed lots of same cultivar 'Hopum' with different PHS percentages, seed lot with 8% PHS (high PHS percentage) showed 30% lower germination than that with 1% PHS (low PHS percentage). The difference of seedling emergence rate and seed viability percentages between the two seed lots was consistent with that of germination percentage. PHS-damaged brown rice was observed protruded embryo, discolored endosperm and fungi infected grains. PHS grains were classified into two groups, PHS-I showing endosperm discoloration in one third of a grain and PHS-II in more than half of a grain. The seed lot with high PHS percentage had much more PHS-II grains than that of low PHS percentage. PHS-II grains showed remarkably lower germination percentage than PHS-I grains and got severely moldy during germination test. In laboratory experiment, morphological changes and re-germination ability of seeds which dried after germination by soaking were tested. Sprouted seeds of 3mm shoot length showed half discolored endosperm and had a strong resemblance with PHS-II grains. Re-germination percentage of 3mm sprouted seeds sharply decreased than 2 mm sprouted seeds. Sprouted seeds which were treated for accelerated-aging (AA) for 24hr at $45^{\circ}C$ were significantly reduced in re-germination percentage compared to that of non-AA-treated sprouted seeds. These results indicate that PHS with over 3mm shoot length can severely damage not only grain appearance but also seed viability, germination percentage and seedling emergence rate. Therefore, we conclude that larger difference of germination percentage or seedling emergence rate between seed lots having smaller difference of PHS percentage might be caused by accelerated seed deterioration in PHS-damaged rice grains.

• Korean Journal of Materials Research
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• v.22 no.4
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• pp.190-194
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• 2012

The formation of high-quality polycrystalline silicon (poly-Si) on relatively low cost substrate has been an important issue in the development of thin film solar cells. Poly-Si seed layers were fabricated by an inverse aluminum-induced crystallization (I-AIC) process and the properties of the resulting layer were characterized. The I-AIC process has an advantage of being able to continue the epitaxial growth without an Al layer removing process. An amorphous Si precursor layer was deposited on Corning glass substrates by RF magnetron sputtering system with Ar plasma. Then, Al thin film was deposited by thermal evaporation. An $SiO_2$ diffusion barrier layer was formed between Si and Al layers to control the surface orientation of seed layer. The crystallinity of the poly-Si seed layer was analyzed by Raman spectroscopy and x-ray diffraction (XRD). The grain size and orientation of the poly-Si seed layer were determined by electron back scattering diffraction (EBSD) method. The prepared poly-Si seed layer showed high volume fraction of crystalline Si and <100> orientation. The diffusion barrier layer and processing temperature significantly affected the grain size and orientation of the poly Si seed layer. The shorter oxidation time and lower processing temperature led to a better orientation of the poly-Si seed layer. This study presents the formation mechanism of a poly seed layer by inverse aluminum-induced crystallization.