• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.35-46
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• 2023

The transplanting period limit considering the rice yield in the Dague region, the inland plains of Gyeongsangbuk-do, was estimated to be July 15^th for early and mid-maturing rice and July 5^th for mid-late maturing rice. However, as the transplanting time was delayed, the characteristics of rice starch changed significantly. In the case of early and mid-maturing rice varieties, the starch granule size increased as the transplanting time was delayed; the opposite tendency was observed for mid-late maturing varieties. In all mature rice types, the late transplanting resulted in a longer pasting time and a higher pasting temperature. In addition, the peak viscosity, breakdown, and gelatinization temperature were significantly lowered, the relative crystallinity degree decreased, and the setback was significantly increased. In the case of Ilpum, a mid-late maturing rice variety, the distribution of amylopectin short chains tended to increase when rice was transplanted on June 30^th.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.32-40
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• 1992

Many studies have been carried out on the graft finishing in order to improve the quality of silk fiber. Various vinyl monomers, for instance, styrene, methylmethacrylate, 2-hydroxyeth-ylmethacrylate and methacrylamide, have been used practically up to date. Among these monomers, methacrylamide has been applied as the most favourable monomer onto silk fibers in recent years. The polymerization mechanism about styrene- and methylmethacrylate-grafted silk fiber has been studied by many researchers. They proposed that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sites were varied by the types of monomer and initiator as well as by the reaction condition. In general. there is another Opinion that monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization, which has not been proved experimentally yet More than 10 years have been passed since methacrylamide was applied on the silk fiber, and at the present time most finishings are being achieved by methacrylamide. However, no attention has been paid to the polymerization mechanism of the methacrylamide-treated silk fiber yeL In this paper, the treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator. The polymerization mechanism of the methacrylamide-treated silk fibers was investigated and analyzed on the basis of the results of infrared spectroscopy, amino acid analysis and scanning electron microscopy. From the results of these instrumental analyses, it can be suggested that polymerization mechanism about the methacrylamide-treated silk fibers is not performed by graft polymerization which has been accepted generally in styrene and methylmethacrylate-grafted silk fibers. The different mechanism is supposed to be due to the difference in monomer types, initiator types and treatment conditions.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.267-273
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• 2000

Temperature-associated emergence patterns for a hydropsychid caddisfly, Hydropsyche kozhantschikovi, were studied from the Wangsuk creek in Kyonggi-do from April to June in 1999. Emerging adults were quantitatively collected by pyramidshaped emergence traps. Water temperature was hourly monitored in 1999. The emergence began at April 15 when the daily mean water temperature rose to ca. $10^{\circ}C$: it rapidly increased and peaked in ca. 10 days, and continued to May 25, lasting 40 days since the starting date. The average number of emerged adults was $35.8\;inds./m^2$ and their sex ratio was male (M) : female (F) = 1 : 2.04. The emergence of males was ca. 2 days earlier than that of females. Daily, the emergence was a bigeminans pattern representing the major peak (66.7%) just after dark ($19:00{\sim}21:00$) and theminor peak (11.1%) just before dawn ($05:00{\sim}07:00$). According to our degree dayaccumulation (DD) model, it respectively required 453.89DD (M: 440.48DD and F: 473.97 DD), 615.71DD (M: 610.18DD and F: 622.09DD), and 820.24DD (M: 828.25DD and F: 804.71DD) to begin, to reach the peak, and to finish the emergence.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.1
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• pp.55-71
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• 1990

The purpose of this study is to find out the basic data for irrigation plans of red pepper and radish during the growing period, such as total amount of evapotranspiration, coefficent of evapotranspiration at each growth stage, the peak stage of evapotranspiration, the maximum ten day evapotranspiration , optimum irrigation point, total readily available moisture and intervals of irrigation date. The plots of experiment were arranged with split plot design which were composed of two factors, irrigation point for main plot and soil texture for split plot, and three levels ; irrigation point with pH1.7-2.0, pF2.1-2.4 and pF2.5-2.8, at soil texture of sandy soil, sandy loam and silty clay for both red pepper and radish, with two replications. The results obtained are summarized as follows. 1.1/10 exceedance probability values of maximum total pan evaporation during growing period for red peppr and radish were shown as 663.6 mm and 251.8 mm. respectively, and those of maximum ten day pan evaporation for red pepper and radish, 67.1 mm and 46.9 mm, respectively. 2.The time that annual maximum of ten day pan evaporation can he occurred, exists at any stage between the middle of May and the late of August for red pepper, and at any stage between the late of August and the late September for radish. 3.The magnitude of evapotranspiration and its coefficient for red pepper was occurred large in order of pF1.7-2.0 pF2.1-2.4 and pF2.5~2.8 in aspect of irrigation point and the difference in the magnitude of evapotranspiration and of its coefficient between levels of irrigation point was difficult to be found out due to the relative increase in water consumption resulted from large flourishing growth at the irrigation point in lower water content for radish. In aspect of soil texture they were appeared large in order of sandy loam, silty clay and sandy soil for both red pepper and radish. 4.The magnitude of leaf area index was shown large in order of pF2.1-2.4, pF2.5-2.8, and pFl.7-2.0, for red pepper and of pF2.5-2.8, pF2.1-2.4, pFl.7-2.0 for radish in aspect of irrigation point, and large in order of sandy loam, silty clay, sandy soil for both red pepper and radish in aspect of soil texture 5.1/10 exceedance probability value of evapotranspiration and its coefficient during the growing period for red pepper were shown as 683.5 mm and 1.03, respectively, while those of radish, 250.3 mm and 0, 99. respectively. 6.The time that the maximum evapotranspiration of red pepper can be occurred is in the middle of August around the date of ninetieth to hundredth after transplanting, and the time for radish is presumed to be in the late of September, around the date of thirtieth to fourtieth after sowing. At that time, 1/10 exceedance probability value of ten day evapotranspiration and its coefficient for red pepper is assumed to be 81.8 mm and 1.22, respectively, while those of radish, 49, 7 mm and 1, 06, respectively. 7.Optimum irrigation point for red pepper on the basis of the yield of raw matter is assumed to be pFl.7-2.0 for sandy soil, pF2.5-2.8 for sandy loam, and pF2.1-2.4 for silty clay. while that for radish is appeared to be pF2.5-2.8 in any soil texture used. 8.The soil moisture extraction patterns of red pepper and radish have shown that maximum extraction rates exist at 7 cm deep layer at the beginning stage of growth in any soil texture and that extraction rates of 21 cm to 35 cm deep layer are increased as getting closer to the late stage of growth. And especially the extraction rates have shown tendency to be greatest at 21cm deep layer from the most flourishing stage of growth for red pepper and at the last stage of growth for radish. 9.The total readily available moisture on the basic of the optimum irrigation point become 3.77-8.66 mm for sandy soil, 28.39-34.67 mm for sandy loam and 18.40-25.70 mm for silty clay for red pepper of each soil texture used but that of radish that has shown the optimum irrigation point of pF2.5-2.8 in any soil texture used. 12.49-15.27 mm for sandy soil, 23.03-28.13 mm for sandy loam, and 22.56~27.57 mm for silty clay. 10.On the basis of each optimum irrigation point. the intervals of irrigation date at the growth stage of maximum consumptive use of red pepper become l.4 days for sandy soil, 3.8 days for sandy loam and 2.6 days for silty clay, while those of radish, about 7.2 days.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.3
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• pp.41-56
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• 1989

The purpose of this study is to find out the basic data for irrigation plans of garlic and cucumber during the growing period, such as total amount of evapotranspiration, coefficients of evapotranspiration at each growth stage, the peak stage of evapotranspiration and the maximum evapotranspiraton, optimum irrigation point, total readily available moisture, and intervals of irrigation date. The plots of experiment were arranged with split plot design which were composed of two factors, irrigation point for main plot and soil texture for split plot, and three levels ; irrigation points with pP 1.7-2.1, pP 2.2-2.5, pP 2.6-2.8, for garlic and those with pP 1.9, pF 2.3, pP 2.7, for cucumber, soil textures of silty clay, sandy loam and sandy soil for both garlic and cucumber, with two replications. The results obtained are summarized as follows 1.There was the highest significant correlation between the avapotranspiration of garlic and cucumber and the pan evaporation, beyond all other meteorological factors considered, as mentioned in the previous paper. Therefore, the pan evaporation is enough to be used as a meteorological index measuring the quantity of evapotranspiration. 2.1/10 probability values of maximum total pan evaporation during growing period for garlic and cucumber were shown as 495.8mm and 406.8mm, respectively, and those of maximum ten day pan evaporation for garlic and cucumber, 63.8mm and 69.7mm, respectively. 3.The time that annual maximum of ten day pan evaporation can be occurred, exists at any stage between the middle of May and the late of June(harvest period) for garlic, and at any stage of growing period for cucumber. 4.The magnitude of evapotranspiration and of its coefficient for garlic and cucumber was occurred in the order of pF 1.7-2.1>pF 2.2-2.5>pF 2.6-2.8 and of pF 1.9>pF 2.3>pF2.7 respectively in aspect of irrigation point and of sandy loam>silty clay>sandy soil in aspect of soil texture for both garlic and cucumber. 5.The magnitude of leaf area index was shown in the order of pF 2.2-2.5>pF 1.7-2.1>pF 2.6-2.8 for garlic and of pF 1.9>pF 2.3>pF 2.7 for cucumber in aspect of irrigation point, and of sandy loam>sandy soil>silty clay in aspect of soil texture for both garlic and cucumber. 6.1/10 probability value of evapotranspiration and its coefficient during the growing period for garlic were shown as 391.7mm and 0.79 respectively, while those of cucumber, 423.lmm and 1.04 respectively. 7.The time the maximum evapotranspiration of garlic can be occurred is at the date of thirtieth before harvest period and the time for cucumber is presumed to be at the date of sixtieth to seventieth after transplanting, At that time, 1/10 probability value of ten day evapotranspiration and its coefficient for garlic is presumed to be 65.lmm and 1.02 respectively, while those of cucumber, 94.8mm and 1.36 respectively. 8.In aspect of irrigation point, the weight of raw garlic and cucumber were increased in the order of pF 2.2-2.5>pF 1.7-2.1>pF 2.6-2.8 and of pF 1.9>pF 2.3>pF 2.7 respectively. Therefore, optimum irrigation point for garlic and cucumber is presumed to be pF 2.2-2.5 and pF 1.9 respectively, when the significance of yield between the different irrigation treatments is considered. 9.Except the mulching period of garlic that soil moisture extraction patterns were about the same, those of garlic and cucumber have shown that maximum extraction rate exists at 7cm deep layer at the beginning stage after removing mulching for garlic and at the beginning stage of growth for cucumber and that extraction rates of 21cm to 35cm deep layer are increased as getting closer to the late stage of growth. 10.Total readily available moisture of garlic in silty clay, sandy loam, sandy soil become to be 18.71-24.96mm, 19.08-25.43mm, 10.35- 13.80mm respctively on the basis of the optimum irrigation point with pF 2.2-2.5, while that of cucumber, 11.8lmm, 12.03mm, 6.39mm respectively on the basis of the optimum irrigation point with pF 1.9. 11.The intervals of irrigation date of garlic and cucumber at the growth stage of maximum consumptive use become to be about three and a half days and one and a half days respectively, on the basis of each optimum irrgation point.

• Korean Journal of Ichthyology
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• v.11 no.1
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• pp.46-51
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• 1999

Age, hatching date and growth in length of juvenile Limanda yokohamae were determined by analysis of microstructure in otoliths. Monthly samples were collected by a beach seine in the shallow water off Gaduk-do from January to December, 1998. The juveniles were collected between February and April. Mean total length was $22.6{\pm}1.77\;mm$ ($\pm$SD) in February, $23.6{\pm}3.86\;mm$ in March, and $38.2{\pm}8.38\;mm$ in April. The core of otoliths ranged from 18 to $21\;{\mu}m$ in diameter and the growth increments were deposited concentrically from the hatching mark. The secondary growth layer began to appear at the 48 to 56-th increment. It indicates that L. yokohamae larvae may be completed the metamorphosis at this time of ca. 52 d after hatching, and moved into the shallow water for demersal stage. The hatching date calculated from the number of daily increments was between late November and early January, showing a peak in December. The total length (L, mm) was related to otolith radius (R, ${\mu}m$); L=0.055 R+5.81 ($r^2=0.88$). The growth in total length was represented by the Gompertz growth curve; $L_t=3.39e^{4.51(1-e^{-0.0067t})}$ ($r^2=0.81$). Daily growth rate was 0.35 mm/d at the age of 70 d and increased up to 0.55 mm/d at the age of 120 d.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.467-478
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• 2009

The super-geomagnetic storms called 2003 Halloween event globally occurred during the period of 29 through 31 which are the following days when the solar flares of X18 class exploded on 28 October 2003. The S4 index from GPS signal strength and the peak electron density ($NmF_2$) from GPS tomography method are analyzed according to the date. The occurrences of the cycle slip and scintillation in the GPS signals are 1,094 and 1,387 on 28 and 29 October, respectively and these values are higher than 604 and 897 on 30 and 31 October. These mean the ionospheric disturbances are not always generated by the period of geomagnetic storm. Therefore, GPS S4 index is useful to monitor the ionospheric disturbances. Behaviors of ionospheric electron density estimated from GPS tomography method are analyzed with the date. At UT = 18 hr, the maximum $NmF_2$ is shown on 28 October. It agrees with $NmF_2$ variation measured from Anyang ionosonde, and the GPS signal are better condition on 30 and 31 October than 28 October. In conclusion, GPS signal condition is relation with geomagnetic activities, and depend upon the variation of the electron density. We will study the long-term data to examine the relationship between the GPS signal quality and the electron density as the further works.

• Journal of Life Science
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• v.30 no.10
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• pp.844-850
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• 2020

Disaster-related extreme weather is rapidly increasing due to climate change. In Korea, typhoons accompanied by rainfall usually approach in August and September, causing great damage. The purpose of this study is to find a gene that regulates the heading date of rice in order to avoid loss of harvest from climate change and typhoons. Cheongcheong/Nagdong doubled haploid (CNDH) was used as the plant material to investigate the location of heading-related genes using QTL and sequence analysis by cloning the gene. In the distribution chart, the heading dates, culm lengths, panicle lengths, numbers of panicles, and 1,000-grain weights all have normal distributions. QTL analysis found 13 contigs on chromosome 8. One QTL, named qHd8, was detected on chromosome 8. The range at qHd8 was approximately 7.7 cM, with RM72 and RM404 markers near the peak. There were 13 contigs and 1 ORF. Protein sequence analysis showed that rice was similar to Os08g0341700, AtSFH13, and AtSFH7 proteins. Os08g0341700, which is involved in signal transduction, is similar to phosphatidylinositol transfer-like protein II, and complete information is not available, but it is believed to play a role in the phosphatidylinositol-specific signaling pathway related to Sec14P.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.170-177
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• 2007

The objectives of this study were to select early, late, and abundant flowering trees of black locust from domesticated and introduced cultivars, and prediction of flowering period by calculation of accumulated temperature in spring. Four cultivars (Debreceni-2, Pusztavacs, Jaszkiseri, and Rozsaszin AC) from Hungary and a cultivar from Beijing, China, were introduced, propagated by seed and planted in a seed orchard. For domesticated black locust, 63 cultivars from 10 locations throughout the country were selected and propagated by root cutting. Criteria for selection of domesticated cultivars were abundant flowering, long flowering period, or abundant nectar production with, if possible, straight stems. Accumulated temperature was calculated from data of a nearby weather station by accumulating daily maximum temperature minus 5 degree Celsius from January 1 up to the date reaching 880 degrees. Daily mean temperature was also used to calculate accumulated temperature up to the date reaching 450 degrees. The percentages of two-year and three-year-old flowering trees propagated by root cutting were higher than that of trees propagated by seeds, while four-year-old trees all flowered regardless of propagation methods. Among the domesticated cultivars, all the cultivars from Ganghwa showed abundant flowering with highest nectar production of 6.5 ul per flower, which was 100% more than other domesticated cultivars and 50% more than Debreceni-2 cultivar with highest nectar production among the introduced cultivars from Hungary. At the end of the eight years of observations, two trees of Debreceni-2 cultivars and a tree from Beijing, China were selected for early flowering trees which flowered 2 to 3 days earlier than average trees, while a tree of Debeceni-2 and three trees from Bejing were selected for late flowering trees which flowered 2 to 3 days later than average trees. It is possible to extend the flowering period of black locust by 4 to 6 days by planting early and late flowering cultivars together. Abundant flowering trees were unable to be selected due to severe damages by leaf gall midges which killed many trees and reduced the crown size of the remaining trees in the seed orchard, and which were first found in Korea in 2001 and now damaging most of the black locust forests in Korea. The prediction of flowering period by accumulated temperature indicated that black locust flowered to a peak when accumulated daily maximum temperature reached 880 degrees Celsius, and when daily mean temperature reached 450 degrees.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.170-170
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• 2022

Grain filling traits of rice were traced to determine the critical temperature that ceased grain filling process, from the late transplanted temperate rice varieties in the field conditions of2020 and 2021. The tested three varieties were transplanted six times with four target heading dates of 20 Aug. (control), 10 Sep., 20 Sep. and 30 Sep. Nine times of sampling were made from a week after heading with three replicates for each treatment. Development of grain filling percentage, grain dry weight and milled rice weight demonstrated sigmoid curves in the first and second transplants of 2020, and in the first to third transplants of 2021. The three grain filling traits in the 2020 third transplants and in the 2021 fourth transplants initially increased with the progress of grain development, and reached the peaks at certain time points, then decreased thereafter. Non-linear regression analyses, performed for the traits in the transplants that showed sigmoid curves except control, indicated that 95% of the final data (95% FD) was attained when the seven-day moving temperature (Sd-MovT) was 8.4-9.6℃, which excluded the cases when the temperature before the dates of 95% FD was lower than that on the dates of 95% FD. Sd-MovT on the date of peak data was 8.5-9.8℃ in the 2020 third transplants and 6.9-8.3℃ in the 2021 fourth transplants. Grain development was observed when seven-day mean temperature (Sd-MT) from 35 to 41 days after heading date was 9.4-10.8℃ in the 2020 third transplants and 10.1-11.9℃ in the 2021 fourth transplants. But Sd-MT of 8.7-9.1℃ in 2020 and 6.9-7.6℃ in 2021, at 42-48 days after heading, resulted in no progress of grain development. Overall, Sd-MovT at the point of stagnated grain development appeared in the range of 6.9-9.8℃. The lowest Sd-MT that showed the progress of grain development was 9.4-9.5℃ and the highest Sd-MT that showed no grain development was 9.1℃, both of which appeared in Odae and Haiami of the 2020 third transplants Therefore it is concluded that critical temperature for the grain development of temperate rice in natural conditions exists between 9.1℃ and 9.5℃.