• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.143-143
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• 2022

Precipitation plays an essential role in water resources management and disaster prevention. Therefore, the understanding related to spatiotemporal characteristics of rainfall is necessary. Nowadays, highly accurate precipitation is mainly obtained from gauge observation systems. However, the density of gauge stations is a sparse and uneven distribution in mountainous areas. With the proliferation of technology, satellite-based precipitation sources are becoming increasingly common and can provide rainfall information in regions with complex topography. Nevertheless, satellite-based data is that it still remains uncertain. To overcome the above limitation, this study aims to take the strengthens of machine learning to generate a new reanalysis of precipitation data by fusion of multiple satellite precipitation products (SPPs) with gauge observation data. Several machine learning algorithms (i.e., Random Forest, Support Vector Regression, and Artificial Neural Network) have been adopted. To investigate the robustness of the new reanalysis product, observed data were collected to evaluate the accuracy of the products through Kling-Gupta efficiency (KGE), probability of detection (POD), false alarm rate (FAR), and critical success index (CSI). As a result, the new precipitation generated through the machine learning model showed higher accuracy than original satellite rainfall products, and its spatiotemporal variability was better reflected than others. Thus, reanalysis of satellite precipitation product based on machine learning can be useful source input data for hydrological simulations in ungauged river basins.

• Wind and Structures
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• v.39 no.2
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• pp.125-140
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• 2024

The simulation of non-stationary wind velocity is particularly crucial for the wind resistant design of slender structures. Recently, some data-driven simulation methods have received much attention due to their straightforwardness. However, as the number of simulation points increases, it will face efficiency issues. Under such a background, in this paper, a time-varying coherence matrix decomposition method based on Diagonal Proper Orthogonal Decomposition (DPOD) interpolation is proposed for the data-driven simulation of non-stationary wind velocity based on S-transform (ST). Its core idea is to use coherence matrix decomposition instead of the decomposition of the measured time-frequency power spectrum matrix based on ST. The decomposition result of the time-varying coherence matrix is relatively smooth, so DPOD interpolation can be introduced to accelerate its decomposition, and the DPOD interpolation technology is extended to the simulation based on measured wind velocity. The numerical experiment has shown that the reconstruction results of coherence matrix interpolation are consistent with the target values, and the interpolation calculation efficiency is higher than that of the coherence matrix time-frequency interpolation method and the coherence matrix POD interpolation method. Compared to existing data-driven simulation methods, it addresses the efficiency issue in simulations where the number of Cholesky decompositions increases with the increase of simulation points, significantly enhancing the efficiency of simulating multivariate non-stationary wind velocities. Meanwhile, the simulation data preserved the time-frequency characteristics of the measured wind velocity well.

• Applied Biological Chemistry
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• v.17 no.1
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• pp.42-48
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• 1974

Hot air thin layer drying method was studied for red pepper, Capsicum annum var. longum as the whole and cut pod states, at various temperature and air velocities. Drying curve of whole pod showed a settling down period followed by the first and second falling rate periods. By lowering the drying temperature, the first falling rate period approached to a constant rate one. Cut drying curve had simple falling rate period and also cut drying method could effectively shorten the drying time. Drying rate constant, k, was varied with time for both the drying methods and the plots of k vs. time in two methods sugested the different drying mechanisms. When an average k was taken as a constant value, the following equations; $M-M_e/M_o-M_e=e^{-0.118t}$ and $M-M_e/M_o-M_e=e(-0.342t^{0.128})$ were applicable for whole and cut drying, respectively.

• Korean Journal of Medicinal Crop Science
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• v.28 no.5
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• pp.339-346
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• 2020

Background: Cnidium officinale Makino have been used in traditional medicine in Northeast Asia. Although gamma-ray mutagenesis has been used to develop breeding resources with novel characteristics, research on the radiation sensitivity of C. officinale Makino is limited. Hence, the optimal gamma-ray dosage for mutation breeding in C. officinale Makino was investigated. Methods and Results: Seedstocks were exposed to doses of gamma rays (5 Gy - 50 Gy), and subsequently planted in a greenhouse. After 30 days of sowing, the survival rates and growth decreased rapidly at doses above 20 Gy, while all individuals died at 50 Gy. The median lethal dose (LD₅₀) was 25.65 Gy, and the median reduction doses (RD₅₀) for plant height, number of stems, and fresh weight were 12.81, 9.32, and 23.26 Gy, respectively. Post-irradiation levels of malondialdehyde (MDA), peroxidase (POD), and chlorophyll in the aerial parts of the plant were quantified using spectrophotometry. Relative to the controls, the levels of MDA and POD increased, while the level of chlorophyll decreased at doses ≥ 10 Gy, indicating cellular damage. Conclusions: A dose of 20 Gy was found to be optimal for mutation breeding in C. officinale Makino.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.279-283
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• 2004

This experiment was carried out at paddy field (commercial silty loam soil) in the southwestern Korea. Pungsannamulkong, a determinate growth habit, was a relatively high yielding and late maturing cultivar, and Han­namkong, a semi determinate growth habit, was a relatively low yielding and early maturing cultivar. Seeds were sowed at two plants and with a planting density of $70{\times}10cm$ on May 26, 2003. Fertilizer was applied prior to planting at a rate of 3.0-3.0-3.4g $(N-P_2O_5-K_2O)\;per\;m^2$ by all basal fertilizations. Experimental design was a randomized complete block with three replications. Seed yield was higher in Pungsannamulkong by 362g per $m^2$ than in Hannamkong of 260g per $m^2$ Also, the number of pod, number of seed, and number of seed per pod were greater in Pungsannamulkong than in Hannamkong. The number of leaves per $m^2$ showed similar with two soybean cultivars up to August 24 but thereafter it decreased in Hannamkong. The leaf area up to August 4 increased in Hannamkong higher than in Pungsannamulkong, but after that time, Pungsannamulkong had greater leaf area than Hannamkong. The shoot and leaf dry matter of two soybean cultivars from June 23 to August 4 were similar but thereafter, Pungsannamulkong had a significantly greater than Hannamkong. Crop growth rate (CGR), relative growth rate (RGR) and net assimilate rate (NAR) for Punsannamulkong were relatively higher than Hannamkong but leaf area ratio (LAR) and specific leaf weight (SLW) showed higher in Hannamkong. Most of leaves distributed in the ranges of 80-90cm and 60-70cm from the soil surface in Punsannamulkong and Hannamkong, respectively. Pods of Punsannamulkong ranged 10-80cm from the soil surface and most of pods were distributed at 40-50cm. Photosynthetic rate at the flowering stage showed a significant difference between cultivars in the upper most leaf position. There was no significant difference of the photosynthetic rate at $7^{tn}$ leaf at the flowering stage, and the uppermost and 7th leaf position at the seed development stage between two soybean cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.291-297
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• 1984

The peanut, unlike other plants, has three distinct steps in the reproductive process. These are the flowers, the peg and the fruit. This research was designed in the field to determine the difference of fruiting habit for each of plant types of peanut (Arachis hypogaea L.) in peanut culture limiting region. Eight cultivars representing four plant types, i.e., Virginia, Spanish, Valencia and Shinpung types. Number of pegs per plant produced in order of Spanish, Valencia, Virginia, Shinpung, Virginia type. The Virginia small seed type produced the most pods per plant. The shinpung type showed more percentage of matured pod than other types and early pot-set habit. Distribution of mature pods for each of branch positions to total mature pods occupied 63% on two cotyledonary branchs, 34% on 3rd to 5th branchs, 3% on over 6th branchs. Shinpung type was considered more favorable plant type than other types for breeding of early maturing high yielding variety because of early pot-set and high percentage of mature pod.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.239-244
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• 2010

The purpose of this study was to identify mungbean (Vigna radiata L.) cultivars with appropriate characteristics for labor saving culture (whole crop feeding and combine harvesting), and to investigate seed quality in the southern South Korea. Cultivar Dahyeon exhibited strong lodging resistance, excellent disease tolerance, and greater pod numbers per plant resulting in higher yield. Cultivar Owool and Keumseong, the two most common mungbean cultivars in Korea, exhibited lower yield than Dahyeon due to weaker disease tolerance or lower pod numbers per plant. Cultivar Samgang demonstrated higher seed starch content, Jangan, Nampyeong, and Keumseong exhibited higher crude protein content, and Sohyeon exhibited higher vitexin and isovitexin contents. However, no statistical differences were found among the cultivars in crude fat content. Unsaturated fatty acid ranged from 51.8 to 57.2%, with saturated fatty acid ranging from 36.2 to 40.3%. We detected five unsaturated fatty acids including linoleic acid (36.1 to 38.6%), linolenic acid (10.3 to 14.7%), and oleic acid (2.7 to 4.6%), and seven saturated fatty acids including palmitic acid (28.7 to 30.9%), stearic acid (2.9 to 4.1%), and arachidic acid (1.5 to 3.7%). There were significant differences between the cultivars in amylogram properties of seeds: the Nampyeong cultivar exhibited a lower gelatinization temperature; Dahyeon was higher in peak viscosity and breakdown; and Sohyeon, Nampyeong, and Dahyeon were lower in setback.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.478-482
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• 2001

This experiment conducted to know physiological characteristics and stress effect on different growth stage of soybean by night illumination. Soybean variety, Shinpaldalkong 2, Keumjungkong and Muhankong were treated by night illumination with 20~30 Lux (0.05~0.08W m$^{-2}$ , 0.24~0.36 $\mu$㏖ S$^{-1}$ m$^{-2}$ ) for 15 days at six different growth stage, seedling, pre-floral initiation, post-floral initiation, pod filling and seed ripening stage. Night illumination delayed flowering to 2~8 days compared to control. Delay of flowering by night illumination severely effected at the pre-floral initiation stage. Stem length was increased all the night illumination treatments except the pod filling stage. Number of nodes in Shinpaldalkong 2 and Keumjungkong 1 were increased until before post-floral initiation stage but in Muhankong were increased until after post-floral initiation stage by night illumination treatments. Number of pods were decreased all the night illumination treatments except seedling stage compared with control. Yield decreased all the treatments and severe the loss rate degree showed the order of prefloral initiation, post-floral initiation, seedling and flowering stage.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.97-105
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• 2014

Peperite exposed along the Dajeonsa basalt in Mt.Juwang, Cheongsong emerged as a consequence of the simultaneity of volcano-sedimentary sequences. This study aims to classify peperites as morphological characteristics and infer the formation process by the field investigation, image analysis, X-Ray Diffractometer and polarization microscope for the magma-sediment interaction mechanism and paleoenvironment. As a result of the field investigation globular(fluidal) peperite is the representative feature at the bottom of Dajeonsa basalt, sub-angular peperite at the middle and irregular peperite at the top. Peperite domains range from sheet and pod or feeder conduit. Although the study that the morphologies of peperite are controled by the sorts of sediment and lava or magma has tended to center around the peperite, the study addresses not single mechanism but the multi-stage mechanism because Mt.juwang peperite, under the same conditions, varies in shapes and sizes and also the ratio of sediments that show the most change of the peperite affects to the formation of peperite.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.189-194
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• 1988

To clarify the varietal differences of resistance to complete flooding, physiological characteristics in relation to flooding resistance in each growth stage of rice plants, the present study was carried out. The rate of survival after flooding at seeding stage of rice plants of the cultivar 'FR 13A' and Ind. X Jap. cultivars were 91.8% and 33.8% to 40%, respectively, while the Japonica varieties were completely dead. The tolerant varieties which has higher rate of survival showed the higher $O_2$ release, the higher catalase activity and lower peroxidase activity according to flooding treatment. Japonica type varieties showed the higher elongation of plant during flooding, lower recovery of flooding damage and the abrupt decrease of yield according to the increase of flooding periods in comparision to Ind. X Jap. crossed varieties when they were flooded at the active tillering stage. When rice plants were flooded at the booting stage, Ind. X Jap. crossed varieties had the higher photosynthesis, respiratory rate, root oxidizing power, ethylene evolution and lower yield reduction in comparision to japonica varieties.varieties.