• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.92-106
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• 1996

Imaginary grass field was assumed suitable as the representative one for simplified estimation of local drought, and a moisture balance booking model computing drought was developed with the limited numbers of its determining factors, such as crop coefficient of the field, reservoir capacity of the soil, and the beginning point of drought as defined by soil moisture status. The maximum effective rainfall was assumed to be the same as the available free space of soil reservoir capacity. The model is similar to a definite depth evaporation pan, which stores rainfall as much as the available free space on the water in it and consumes the water by evaporation. When the pan keeps water less than a certain defined level, it is droughty. The model simulates soil moisture deficit on the assumed grass field for the drought estimation. The model can assess the water requirement, drought intensity, and the index of yield decrement due to drought. The influencing intensity indices of the selected factors were 100, 21, and 16 respectively for crop coefficient, reservoir capacity, and drought beginning point, determined by the annual water requirements as influenced by them in the model. The optimum values of the selected factors for the model were respectively 58% for crop coefficient defined on the energy indicator scale of the small copper pan evaporation, 50 mm for reservoir capacity on the basis of the average of experimentally determined values for sandy loam, loam, clay loam, and clay soils, and 65% of the reservoir capacity for the beginning point of drought.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.3
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• pp.209-225
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• 1997

Daily rainfalls and evaporations from copper pan measured in Suweon from 1964 to 1996 were figured respectively so that past soil moisture deficits can be understood clearly at a glance in relation to the characteristics of weather. Past drought intensities in Suweon were computed on the basis of Oh's 50mm pan model estimating drought in terms of daily, monthly shortage of evapotranspiration and growthless time fraction. Yearly differences in drought seem to result mainly from yearly differences in rainfall distribution and intensity, because there is the periodical similarity in evaporation from year to year. The most intense drought continued from December, 1964 to June, 1965 for 190 days and the most frequent rainfalls were observed from June, 1989 to August, 1990 for 15 months. The applied Oh's drought estimation model was reinforced with figuring programs with a view to later application for other districts. Present economic value index of irrigation were distributed in the range of 120% to 210% of one season yield for spring chinese cabbage, calculated on the basis of 10 year's accumulation of its expectable future yield increase. Therefore, the same value can be invested for the installation of new irrigation system even only for spring chinese cabbage, if its depreciation period is 10 years.

• KAPE Magazine
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• s.144
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• pp.2-3
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• 2008

• Proceedings of the Korean Society of Crop Science Conference
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• 2002.10a
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• pp.55-55
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• 2002

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.133-138
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• 2006

To differentiate barley responses to drought and salt stress, barley seedlings at the second leaf stage were treated with 218 mM NaCl and 29.5% PEG6000 iso-osmotic to 218 mM NaCl for 6 days. Shoot fresh weight and leaf relative water content of barley seedlings were more reduced by drought compared to salt stress. Hydrogen peroxide content increased under both stress conditions, but its accumulation was more severe at 6 days after salt stress. The activity of ascorbate peroxidase, glutathione reductase (GR) and catalase (CAT) was enhanced until 4 days after salt stress. On the other hand, the activity of GR and CAT increased gradually until 6 days after drought. Among the amino acids measured in this study, the accumulation of glycine, arginine and GABA (${\gamma}-aminobutyric$ acid) was lower under salt stress than drought. However, considerably larger amount of proline was accumulated by salt stress. It is concluded that the antioxidant enzymes activity and amino acid content of barley seed-lings were differently regulated in response to the isoosmotic condition of salt and drought stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.8-16
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• 2015

The objective of this study was to evaluate the drought tolerance in maize seedling using leaf rolling. Nineteen maize resources, seven Nested Association Mapping parents lines, six Korean commercial cultivars, and six Southeast Asia commercial cultivars, were used to examine drought tolerance. The leaf rolling scores were measured on each leaf in three stress conditions with moderate drought (10%), severe drought (7%), and extreme drought (5%). Generally leaf rolling score of seedlings increased at the lower soil water potentials (5~7%). As a result, drought-tolerant cultivars showed lower leaf rolling score (below 2.5) than the drought sensitive cultivars (above 3.5). Nine varieties, NK4043, CML322, DK9955, NK4300, Ki11, DK8868, CML228, LVN99, and LVN10, have been selected for tolerance to drought stress. These results suggest that the leaf rolling score in maize seedling has been made available to indirect index for drought tolerance.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.914-924
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• 2018

The purpose of this study is to provide the basic data for the shoulder strengthening exercise by analyzing the% MVIC of the muscle activity in the shoulder rotator cuff by the difference of the stance posture and the anatomical plane. 8male subjects were randomly assigned to perform the shoulder rotation exercise 10 times on the frontal plane, the horizontal plane, the sagittal plane and the two legs stance posture, the one leg stance posture, the lunge posture. Measured muscle activity of supraspinatus, infraspinatus, teres minor, anterior deltoid, rectus abdominis, erector supinea, pectoralis major, lattisimus dorsi during exercise. A repetitive one-way ANOVA was performed using the SPSS 22.0 statistical program. First, during the external rotation on the frontal plane, the erector spinea was higher in the lunge posture than in the two legs stance posture and the one leg stance posture, And during the internal rotation on the frontal plane, the muscle activity of suprapinatus was higher in one leg stance posture than in the two legs stance posture and more so in the lunge posture. Second, during the external rotation on the horizontal plane, the muscle activity of deltoid anterior was higher in the one legs stance posture and in the lunge posture than in the two legs stance posture, and during the internal rotation on the horizontal plane, the muscle activity of infraspinatus was higher in the lunge posture than in the two legs stance posture and one leg posture, and the muscle activity of pectoralis major was higher in two leg stance posture than in the one legs stance posture and more so in the lunge posture. Third, during the external rotation on the sagittal plane, muscle activity of rectus abdominis was higher one leg stance posture in the lunge posture than in two leg stance posture. During the internal rotation on the sagittal plane, muscle activity of supraspinatus was higher one leg stance posture in the lunge posture than in two leg stance posture. And muscle activity of infraspinatus was higher in the lunge posture than in two leg stance posture, one leg stance. And muscle activity of Rectus abdominis was higher in the lunge posture and one leg stance posture than in the two legs stance posture. And muscle activity of Erector spinea was higher in the two legs stance postur and lunge posture than in the one leg stance posture. In conclusion, the differences in stance and shoulder anatomy have different effects on the muscle activity of the shoulder rotator exercises, and this is expected to be a more positive exercise program when applied to the shoulder strengthening exercise program.

• KCID journal
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• v.4 no.2
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• pp.48-61
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• 1997

Drought index calculation method using principal hydrological factors, such as precipitation amount and reservoir storage ratio, can estimate the duration and the intensity of drought. It is not easy to establish an universal criteria of drought, since th

• Journal of Life Science
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• v.12 no.5
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• pp.544-548
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• 2002

The object of this study was to investigate nitrogen fixation activity of rhizobium inoculated at seed coat when drought condition was applied in flowering period of soybean c.v. Samnamkong. The rhizobia used in this experiment were indigenous rhizobium, R2l4, RJl-29, USDA110 and USDA122. The experiment was done with 1/2000 Wagner pots in laboratory and greenhouse and was tested in completely randomized design with four replications. Nitrogen fixation activity in coventional culture was the highest in R2l4 and indigenous rhizobium among the five rhizobia strains. As given drought condition from flowering to maturity, nitrogen fixation activity was higher in R2l4 and RJl-29 than indigenous rhizobium. Leaf area and relative index (drought/convention) of pod weight were higher in USDA122, RJl-29 and R2l4 than indigenous rhizobium as given drought condition from flowering to maturity. High positive correlation was observed between nitrogen fixation activity of rhizobium and relative index(drought/convention) of pod weight. High negative correlation was observed between respiration of plant and relative index (drought/convention) of leaf area.

• Journal of the Korean association of regional geographers
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• v.11 no.4
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• pp.429-439
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• 2005

The propose of this study is to identify distributional characteristics of winter droughts through occurrence frequencies and to analyze synoptic characteristics on the sea level pressure fields and 500hPa levels in Korea. The regional distributions of winter droughts in occurrence frequency vary according to the monthly regional distributions of the variabilities of precipitation in Korea. In January and December, the eastern parts of Korea where the variabilities of precipitation show high, have high rate of drought frequencies, while the western parts have low rate of it. It means that the regional distribution of the drought frequencies in January and December shows the east-high and west-low pattern, In February the frequencies show the north-high and south-low pattern. In the distributions of the sea-level pressure and 500hPa level height anomalies, the positive anomalies appear around Korean Peninsula and Siberian high area, the negative anomalies on the Aleutian low area and the western parts of North Pacific Ocean during the drought period in January and February. The droughts appear when the inflow of warm and humid air from the south eastern parts blocked by the prevailing pressure patterns of the west-high and east-low. Therefore, the zonal wind of the Korean Peninsula is strong. The droughts of December reflect not only low frequencies of cyclone occurrence, also small inflow of warm and humid air from the southern parts stemming from positive anomalies over whole middle latitude of eastern parts of Asia including Korean Peninsula.