• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.140-148
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• 2018

As the global warming causing desertification increase, there is growing concern about damage of crops. It was to investigate how the treatment with hydrogen peroxide before leaf development affects the growth and yield of sorghum for minimizing a damage of crops to drought. The germination experiment was conducted at alternating temperature of $25^{\circ}C/20^{\circ}C$(12 hr/12 hr) under water stress condition of 0 ~ -0.20 MPa adjusted with PEG solution containing 0 and 10 mM $H_2O_2$. In order to know the effect of foliar application of hydrogen peroxide on the growth of sorghum, 10 mM hydrogen peroxide was treated to leaves at 3-leaf stage of sorghum growing in greenhouse conditions. Seed germination rate was increased by 20% in hydrogen peroxide treatment as compared to the Control. under water stress conditions (-0.15 ~ -0.20 MPa). The length of seedlings was also on the rise by the hydrogen peroxide treatment. In the greenhouse pot experiment, the morphological characteristics (plant height, stem diameter, leaf length, and leaf number) and physiological characteristics (chlorophyll content, chlorophyll fluorescence (Fv/Fm), stomatal conductance) were higher in the plants treated with hydrogen peroxide under the drought stress condition than those of plants of $H_2O$ treatment. Experiment conducted with the soil moisture gradient system showed that the foliar application of hydrogen peroxide increased photosynthetic ability of sorghum plant with respect to SPAD value and stomatal conductance and rooting capacity (root weight and root length) under drought condition. Generally, hydrogen peroxide treatment in sorghum increased the tolerance to drought stress and maintained better growth due to ameliorating oxidative stress.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.254-260
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• 2015

Changes of the growth, quality and physiological response of Chinese cabbage cv 'Chunkwang' in response to five different temperature treatments based on climate change scenario were investigated during the growing season. The treatments consisted of normal year temperature $-2.0^{\circ}C$ (I), normal year temperature (II; Control group), normal year temperature $+2.0^{\circ}C$ (III), normal year temperature $+4.0^{\circ}C$ (IV), and normal year temperature $+6.0^{\circ}C$ (V). Regarding fresh weight, number of leaves, and leaf area were high in group IV, and V before the head formation stage, but it has decreased during the later growth period. Rate of frangibleness sympton was the highest in group V as 85.7%, and it was decreased in group IV (64.3%), group III (28.6%), group II (14.3%), and group I (7.1%). Regarding photosynthetic rate, group III, IV, and V showed relatively high photosynthetic rate at 20 DAP but it was reduced dramatically during the later growth period. Transpiration and stomatal conductance showed the similar trend with the photosynthetic rate. When comparing the chlorophyll fluorescence reaction of each treatment group at 50 DAP, Fv/Fm in group I was highest as 8.04 among all treatment groups and the lowest in group IV as 7.15.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.171-178
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• 2008

We have found the clusters of tiny spiny puffball-like mushrooms growing gregariously in fairy ring (arcs) rimmed by a zone of darker green grass in the golf courses. Macroscopic as well as microscopic characters were examined for the morphology of fruiting body. Exoperidium is thin and densely spiny with minute fibrillae at early stage. The connivent spines were soft and quite persistent. In age, the fibrillae scrumble away with a powdery coating, which leaves white endoperidium becoming pale brown. It's interior was white and fleshy at first, but turns into an olive-colored dust as the gleba, the spore-producing tissue, develops to maturity and loaded with olive-brown spore mass. Then, distinct apical pore developed on the endoperidium. Rudimentary subgleba(sterile base) was narrow, chambered, delineated from the gleba by a membrane in young material. These characters suggested this fungus is a Vascellum, a member of the family Lycoperdaceae. The shapes of the spores were globose, echinulate, $3{\sim}3.5{\mu}m$ in diameter, thick-walled, and olive brown. Capillitial threads were $8-9{\mu}m$ wide, mostly colorless in KOH solution and thin-walled, which designated as "paracapillitium". This is an another character that distinguishes this mushroom from Lycoperdon spp. The spines developed on exoperidium were characteristically connivent; their apices joined together in a point, leaving a space below, which gives the appearance of vault to each group of usually 5 to 6 fibrillae. Based on the above characters, this fungus is identified as Vascellum curtisii (Berkeley). The characters distinguishable this from Lycoperdon pulcherrimum, and Vascellum pretense are discussed in detail. Control trial was also attempted. Strong vertical raking(SVR) followed by applying 500x detergent solution (Spark, Aekyung Co. Seoul) resulted in excellent control over any other treatments. In this plot, fruiting body was not developed throughout the end of mushroom growing season.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.22-28
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• 2001

An optimum seeding date for carrots growing in Jeju was determined. In early growth stage, the number of leaves was more in Hyang-yang #2 cultivar (HY2) than that in the others, meanwhile that of Hukjun 5 chon (H5) and Shinhukjun 5 chon (S5) was higher in the latter half of the growing season. The weight of leaves was greater in HY2 until 2 months after seeding, but thereafter drastically increased and resulted significant difference at harvest in S5. The length of roots was greater in H5 and S5 than in HY2 when seeded on July 17 and measured after September 13, but it was similar in all cultivars when seeded on August 1 and later. The diameter of the roots was greatest in HY2, regardless of seeding dates, meanwhile no difference was found among other cultivars. The weight of roots was greatest in HY2 when seeded on July 17, August 1 or later, meanwhile it was greater in H5 after November, when seeded on August 15. The percentage of roots cracked was 20, 15, and 10% respectively for HY2, S5 and H5. The percentage of roots branched was 0.3% in HY2. The percentage of roots cracked or branched was much higher when seeded on August 1 than on July 17, and was high (40%) in HY2 and S5, compared to H5 when seeded on August 15. The content of sucrose, glucose and fructose increased until 110 days after seeding in all cultivars, but fructose and glucose contents decreased in about 135 days after seeding, but sucrose contents increased continuously even after 135 days. Sucrose content increased and fructose and glucose contents decreased in S5, but this trend was reversed after late November. Sugar contents was different among the cultivars seeded on August 15, while sucrose content decreased and glucose and fructose contents increased with time. The content of ${\beta}$-carotene was more than 12,000 IU in all cultivars, but decreased in 170 days after seeded on July 17. The content was highest in HY2 and followed by S5 and H5 in order. It was not different among the cultivars in 170 days after seeding on August 1, but was higher in S5 than the other cultivars in 170 days after seeded on late and decreased with seeding date.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.2
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• pp.96-101
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• 2021

This study was conducted to determine the effect of horse manure compost application on Italian ryegrass (IRG) yield and volcanic ash soil characteristics. Because the number of horses in Korea is growing, the amount of horse manure is growing. Jeju island, where about 55 % of the horses live, is composed of volcanic ash soil. This study was conducted for about 7 months. Sowing was conducted on October 2019. Harvesting was conducted at heading stage(2020.5.). Five treatments were established based on the horse manure compost composition. These were 100 % chemical fertilizer (CF), the combination of 50 % horse manure and 50 % chemical fertilizer (combination), horse manure with 50 % nitrogen (HM 50 %), horse manure with 100 % nitrogen (HM 100 %), and horse manure with 150 % nitrogen (HM 150 %). The plant height and dry matter yield were investigated to determine the forage yield and the soil characteristics of pH, total nitrogen, available phosphate, and organic matter were analyzed. The plant heights in the CF, combination, and HM 150 % treatments were 147.8 cm, 144.3 cm, and 147.1 cm respectively (Table 2). Dry matter yield in the CF treatment was about 23,807 kg/ha, which tended to be the highest dry matter yield. HM 150 % and the combination treatment were about 18,804 and 18,455 kg/ha, respectively, which tended to be the highest dry matter yield of the treatments amended with horse manure compost. The dry matter yield of the HM 100 % and HM 50 % treatments was about 15,801 kg/ha and 14,446 kg/ha, respectively (Table 2). The pH of the surface soil tended to increase after the experiment. The soil pH of the HM 150 % treatment was significantly higher than the soil pH of the other treatments. The pH was affected by the amount of horse manure compost, with a pH of 8.1. The available phosphate in the treatments in which horse manure compost was added was higher than the available phosphate in the CF treatment. And the available phosphate in the HM 150 % treatment was significantly higher than the available phosphate in the other treatments (p < 0.05)(Table 3). These results suggest that 50 % horse manure should be applied to IRG as the basal fertilizer and the remaining 50 % should be chemical fertilizer as the top fertilizer. This can provide the proper IRG dry matter yield with less effect on volcanic ash soil.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.225-246
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• 2010

The family environment children are exposed to growing up greatly influences their future potential and achievements. Previous findings show that changes in family structure during childhood, particularly those resulting from divorce or death, cause lasting negative consequence that affect the child physically, psychologically, economically, and socially. Unfortunately, single-parent households are becoming increasingly common in Korea, nearly doubling to more than a million cases in the last two decades. Existing domestic and international studies of this area tend to focus on the short-term effects of growing up in a single-parent household. In addition, these studies group their samples in ways that result in findings that may be too broad or are not necessarily an accurate representation of the subjects. This study attempts to address some of these shortcomings by focusing on the long-term effects of how changes in family structure early in children's lives affect achievement during their transition to adulthood. In addition, it takes into account the development cycle the child is in at the time of family restructuring, and what kind of long-term effects result from that. In this analysis, we find that there are several cases of statistically significantly differences in domain achievement depending on the developmental stage the child was in when the parental divorce or death occurred. The findings indicate that changes in family structure during the infant/toddler period influence health condition and depression, while changes in family structure during middle-childhood and adolescence do not. Meanwhile, changes in family structure during any point in the developmental stages have negative effects on educational attainment, with the severity of these negative effects depending on when the family changes occur. The negative effect on educational attainment is most prominent when a change in family structure occurs during the infant/toddler period, followed by adolescence, then middle-childhood.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.473-481
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• 2023

Pinus densiflora is a fixed-growth coniferous species that elongates its shoot once a year and finishes growing in early summer. However, it may produce additional shoots in the same year in response to external stimuli, called abnormal shoot growth. This study investigated the effects of open-field summer warming and drought on the abnormal shoot growth of P. densiflora seedlings. In March 2022, two factorial combinations were constructed, including two temperature treatments (control and 4℃ increase) and two precipitation treatments (control and drought), with five replicates for each combination. The temperature treatment was performed for 87 days from May 14 to August 8, 2022, and the precipitation treatment was performed for 33 days from May 14 to June 15, blocking 100% of the ambient rainfall. The abnormal shoot occurrence rate and leaf unfolding stages were measured in November, and the shoot and root collar diameter growth rates were calculated by comparing the seedling height and root collar diameter measured in August(after the cessation of treatment) and October(after the end of growing period) with the initial values (i.e., May 2022). The abnormal shoot occurrence rate significantly increased under the warming treatment, showing a 410.6% increase in the warming plots (38.4%) compared to the control plots (7.5%). There was no significant difference in the shoot and root collar diameter growth rate regarding warming and drought treatments. Abnormal shoots may have been affected by high temperatures by inducing early transition to the next ontogenetic stage.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.77-82
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• 1979

Wilting and transpiration charactistics of Panax ginseng leaves were investigated at two temperature levels. Water potential and water absorption characteristics of leaf segments were also observed. Soybean leaves were compared. 1. Ginseng leaves were thiner, higher in water content and lower in dehydration rate. But time required to reach permanent wilting point (pwp) was less than half of that of soybean leaves because water content at pwp was about two times higher (80% of initial water for ginseng and 50% for soybean leaves). The time was shorter under high air temperature. 2. Transpiration rate was about a quater of soybean leaves and lower at $33^{\circ}C$ than $23^{\circ}C$, indicating that ginseng leaves are less tolorant to high air temperature. 3. Ginseng leaf segment showed smaller water free space but greater water deficit and little difference in was absorption rate. 4. Water potential of leaves measured by liquid immersion method was lower than that of soybean leaves. 5. Above results strongly suggest that ginseng plants are more susceptible to water stress. Thus greater light intensity during leaf growing stage (April to June) is recommendable to increase stomate frequency resulting greater transpiration rate and high temperature tolerance during July and August. Abundant water around roots seems to be beneficial as long as oxygen is not limited in rhizosphere.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.3
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• pp.43-64
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• 2011

Objectives: The purpose of this study was to provide the nutritional education data of the fruit and vegetable eating habits and dietary fiber intake of male and female high school students in the Daegu area. Methods: A survey was conducted on 300 male/female students from four general high schools in the City of Daegu, and the survey included questions ongeneral characteristics, dietary habits, eating behavior patterns and dietary intake. A 24-hour recall method was used for the dietary intake, and the surveyed dietary intake information was analyzed using the Computer Aided Nutritional analysis program (CAN 3.0)--dietary fiber intake, in particular. The data was analyzed using the SPSS window 12.0 program. Results: The average ages of boys and girls were 16.8- and 15.6-years old, respectively. A classification based on BMI showed the following: the low-weight student group was comprised of 10.3% boys and 31.6% girls; the normal-weight group 68.4% boys and 67.5% girls; and the overweight group 21.3% boys and 0.9% girls, whereby showing a significant difference between boys and girls. Vegetable intake showed the following: the ratio of the response of 'taking it once a day' was more than 70%, which showed the low frequency of fruit intake; the ratio of 'taking it more than five times a week' was 53.0% for boys and 68.4% for girls, which showed a higher intake frequency for girls over boys; and the daily dietary fiber per 1,000kcal was 7.1g for boys and 8.2g for girls, whereby showing a significant difference between boys and girls. The meals that contributed most to dietary fiber intake were the school meals, whereas the dietary fiber intake rate through breakfast was the lowest among the three daily meals. The food groups that contributed to dietary fiber intake were vegetable, grains and flavoring matters for boys and vegetable, grains and fruits for girls. Conclusions: In order to increase the daily dietary intake for growing adolescents, who are in an important stage for building the foundation of health, it's recommended that, in addition to the supplement for insufficient dietary fiber through a regular breakfast consisting of high dietary fiber content foods, nutrition-related education about the effects of dietary fiber on the human body be conducted.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.16-27
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• 2011

Embryo is a very early stage of the development of multicellular organism such as animals and plants. It is an important research target for studying ontogeny because the fundamental body system of multicellular organism is determined during an embryo state. Researchers in the developmental biology have a large volume of embryo image databases for studying embryos and they frequently search for an embryo image efficiently from those databases. Thus, it is crucial to organize databases for their efficient search. Hierarchical clustering methods have been widely used for database organization. However, most of previous algorithms tend to produce a highly skewed tree as a result of clustering because they do not simultaneously consider both the size of a cluster and the number of objects within the cluster. The skewed tree requires much time to be traversed in users' search process. In this paper, we propose a method that effectively organizes a large volume of embryo image data in a balanced tree structure. We first represent embryo image data as a similarity-based graph. Next, we identify clusters by performing a graph partitioning algorithm repeatedly. We check constantly the size of a cluster and the number of objects, and partition clusters whose size is too large or whose number of objects is too high, which prevents clusters from growing too large or having too many objects. We show the superiority of the proposed method by extensive experiments. Moreover, we implement the visualization tool to help users quickly and easily navigate the embryo image database.