• The Korean Journal of Ecology
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• v.19 no.4
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• pp.321-328
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• 1996

The profile and concentration of monoterpene metabolites in the leaf and stem of Artemisia princeps var. orientalis were quantified, and seasonal variation in monoterpenes of Artemisia plant was investigated. Samples were taken from five sites at the campus of Kyungnam University during maturing season. Monoterpenes in leaf and stem were analyzed using gas chromatography-mass spectrometry (GC-MS). The major constituents of A. princeps var. orientalis in both the leaf and stem were 21 monoterpenes.$ {\alpha}-pinene,\;{\beta}-pinene,\;{\beta}-myrcene$, dl-limonene, naphthalene and unknown monoterpenes with 5.49 and 16.27 of retenstion time were present in high concentrations of compounds identified on the leaf and stem of A. princeps var. orientalis. The cmounts of total monoterpenes of leaf were from two to five times higher than stem and rapidly decreased with the time, while that of stem was constnat except early spring. Most of the high percentage of monoterpenes in the leaf were those with later retention time. These results indicated that monoterpenes yields are considered to be more variable than monoterpene composition in responding to the time in both the leaf and stem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.227-233
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• 2014

This experiment was undertaken to develop triple cropping systems for winter cereal crops for forage, early maturing rice and oats, and to select a winter forage crop in order to determine rice transplanting time at paddy fields in the southern region. Also, the productivity and feed value of the resulting forage crops were examined. When winter cereal crops used for forages are first harvested at the early maturing rice transplanting period, and again harvested during the winter forage crop harvesting period, the fresh yield and dry matter yield of rye were 32.0, 42.3 ton/ha and 5.8, 16.5 ton/ha, respectively, demonstrating higher yields than other winter crops. The early maturing rice, 'Jopyeong', transplanted on June 4 had a lower percentage of ripened grain compared to those transplanted on May 6, and milled rice yield transplanted on June 4 was also decreased by 22%. Thus, the results showed that early transplanting was profitable. Regarding the oats grown during the fall cropping season, the heading date for the oats sown first was on October 10, but the heading was not observed in those sown later. Dry matter yield and TDN yield of the second sowing was less than 50% compared to the first. Consequently, rye may be the most suitable winter forage crop for triple cropping systems. Early transplanting of 'Jopyeong' after rye harvesting before April 30 in addition to timely sowing of oats in the fall season would be profitable for rice and forage production using triple cropping systems in the southern region.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.298-308
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• 1988

This study was carried out to get infirmation for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in Japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effentive ripening.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.309-314
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• 1988

This study was carried out to get information for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5 days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effective ripening.

• FLOWER RESEARCH JOURNAL
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• v.26 no.4
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• pp.195-201
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• 2018

The plant morphological and chromosome characteristics of 'Bonanza', 'Coral Candy' and 'Purple Crystal', a formolongi-Asiatic (FA) interspecific hybrid species bred at the National Institute of Horticultural Science, Rural Development Administration (RDA), were investigated in this study. The flowering time of these species were found to have some variation. 'Bonanza' flowers in the middle to late June (medium-late maturing cultivar), 'Coral Candy' in the mid of June (medium maturing cultivar), and 'Purple Crystal' was observed to be in early June (early maturing cultivar). The flowering direction of all three cultivars are upward facing flowers and having a weak fragrance. The height of the plants was recorded in the range between 101.0 cm ('Purple Crystal') to 142.3 cm ('Bonanza'), thus they are able to develop cut flowers with excellent stem elongation. Flower diameters of 'Bonanza' (17.1 cm) and 'Coral Candy' (16.9 cm) were classified to be large sized flowers. On the other hand, 'Purple Crystal' had a narrow flower diameter (12.3 cm) with an outer petal width of more than 4.0 cm. Leaf length was observed for 'Bonanza' (15.7 cm), 'Coral Candy' (19.7 cm), and 'Purple Crystal' (11.1 cm). Chromosome analysis was done using FISH technique. Results revealed that all three cultivars were observed as triploids (2n=3x=36). FISH analysis also showed 5S/45S rDNA of 'Bonanza', 'Coral Candy' and 'Purple Crystal' as 4/11 loci, 4/12 loci, and 4/11 loci, respectively. The results of the FISH analysis are useful as markers to distinguish cultivars, since the patterns of rDNA observed on the remaining chromosomes are significantly different except FISH patterns of chromosome #3.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.47-55
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• 2020

This study was conducted to evaluate the flowering characteristics of 22 soybean (Glycine max Merrill) varieties of North Korea and classify the flowering group by the flowering date. The flowering date and the days required for flowering with the different planting times on May 31, June 19, June 30, July 3, and July 4 were investigated at the agricultural experimental field of Korea University for three years from 2017 to 2019. The flowering date and the days for flowering of "Yeonpungkong", an early maturing soybean cultivar of Korea, were July 18 and 48 days, respectively, at the planting time of May 31, those of "Daewonkong", a mid-late maturing cultivar, were July 30 and 60 days, respectively. Based on the flowering dates of "Yeonpungkong" and "Daewonkong", North Korean soybean varieties were classified into six flowering groups. Eight North Korean soybean varieties had the flowering dates earlier than "Yeonpungkong", including "Brekkhat" classified into the early flowering group. The range of flowering date was July 2 to 15 at planting time of May 31. Twelve North Korean soybean varieties had flowering dates similar to or later than "Daewonkong", including "Chang Dan Bac Mok" classified into the mid-late flowering group. The range of flowering date was July 24 to 30 at the planting time of May 31. For flowering response to environmental stimulus, all of the mid-late flowering varieties of North Korea responded to "photosensitive or day-length" for flowering reaction. The early flowering varieties were divided by "photosensitive" response and "temperature" response variety.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1101-1109
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• 2004

Experimental measurements of flame structure and soot characteristics were performed fur ethene inverse diffusion flames (IDF). IDF has been considered as the excellent flow field to study the incipient soot because soot particle do not experience the oxidation process. In this study, LIF image clarified the reaction zone of IDF with OH signal and PAH distribution. laser light scattering technique also identified the being of soot particle. To address the degree of soot maturing, C/H ratio and morphology of soot sample were investigated. From these measurements, the effect of flow residence time and temperature on soot inception could be suggested, and more details on soot characteristic in the IDF was determined according to fuel dilution and flame condition. The fuel dilution results in a decrease of temperature and enhancement of residence time, but the critical dilution mole fraction is existed for temperature not to effect on soot growth. Also, the soot inception evolved on the specific temperature and its morphology are independent of the fuel dilution ratio of fuel.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.17-23
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• 1987

The purpose of this study was to evaluate the sealing properties of endodontic cavity filling materials according to the time intervals after filling. Access cavities were prepared in extracted human premolar or molar teeth and filled with caviton, zinc oxide eugenol cement, zinc oxide eugenol cement with a base of gutta percha stopping and gutta percha stopping. After filling at the intervals of immediate, 2 days and 2 weeks the teeth were immersed for 2 weeks in 1% methylene blue solutions. Longitudinal sections were obtained from approximately center of teeth and the depth of dye penetration into the access cavities were observed by 10${\times}$macrolens. The following results were obtained. I. All the materials experimented showed varying depth of dye penetration. 2. Of the material tested, caviton showed the best marginal sealing qualities regardless of the time intervals after filling and the sealing properties of the gutta percha stopping was the worst. 3. Both in zinc oxide eugenol cement and zinc oxide eugenol cement with a base of gutta percha stopping, the fillings allowed to mature for 2 days in normal saline solution showed the best sealing properties and those with no maturing time revealed the worst sealing qualities. 4. The sealing qualities of zinc oxide eugenol cement with a base of gutta percha stopping revealed slightly lower depth of dye penetration than that of zinc oxide eugenol cements.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.512-516
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• 2013

Pear cultivar 'Sinhwa' (Pyrus pyrifolia var. culta Nakai) was originated from a cross between 'Niitaka' and Whasan' with the aims of improving the fruit quality and the traits of cultivation and of early maturing more than 'Whasan' cultivar at Pear Research Station of National Institute of Horticultural & Herbal Science, Rural Development Administration in 1995. 'Sinhwa' was preliminarily selected in 2004 and named in 2009. The tree shows vigorous growth habit and semi-spread characters like 'Niitaka'. Furthermore, it has a sufficient and well upkeep of the flower bud, so it can be more easily cultivated in orchards. In the flower characteristics, flowering time of 'Sinhwa' is $11^{th}$ April like as maternal parent 'Niitaka'. Also 'Sinhwa' has short of pollen grains, so it is need above two pollinizer cultivars. 'Sinhwa' is highly resistant to black leaf spot (Alternaria kikuchiana) and relatively strong to pear scab (Venturia nashicola) in field condition. The optimum harvest time is around Sep. $15^{th}$ in Naju, which is ahead of 'Whasan' about 10 days in the harvest period. The fruit shape is oblate and fruit skin color is yellowish-brown during harvesting time. The average weight of fruit is 627 g, and the soluble solids content is $13.0^{\circ}Brix$. The flesh is very soft and juicy, and renders good eating quality. Shelf life is about 30 days under the room temperature condition.