• Journal of Korea Water Resources Association
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• v.39 no.5 s.166
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• pp.395-403
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• 2006

This study suggests the use of a simple method, called the unit concentration response function(UCRF) for predicting travel time and dispersion of pollutants with the minimum information of study area instead of numerical models which are widely used In the Previous studies. However, the numerical models require time-consuming, tedious effort, and many data sets. So we derive the UCRF using some components such as travel time, peak concentration, and passage time of pollutant etc. We use the regression equation for the estimations of components which were developed from the investigations of many river basins in USA. This study used the regression equaiton for the UCRF to the accident of Dichloromethane leak into the Nakdong River occurred on June 30, 1994 and applied the UCRF for the predictions of travel time and dispersion. The predictions were compared with the results by QUAL2E model. The results by the regression equaiton and QUAL2E model had a good agreement between observed and simulated concentrations. Therefore, the regression equation for the UCRF which can simply estimate travel time and concentration of pollutants showed its applicability for the ungaged basin.

• Journal of Conservation Science
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• v.7 no.2
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• pp.80-85
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• 1998

The structure, dimensions, condition and other characteristics of the Koryo Buddhist Canon (the Koreana Tripitaka) Printing Wood Blocks stored at the Haein-sa Monastery were surveyed to obtain basic data needed for the conservation of the Wood Blocks. The dimensions of the Wood Blocks Were measured and we could figured out the blueprint designed at the time of the carving the Wood Blocks. The dimensions of the wooden board were as follows: width, 8'chi'('cun' in Chinese, 24 cm);thickness, 1 'chi' (3 cm); length, 2'cha' ('chi' in Chinese) and 3 'chi' (68 cm) or 2 'cha' and 6 'chi' (78 cm). The dimensions of the end pieces were as follows: width, 1 'chi' and 5 'fun' (4.5 cm; thickness, 1 'chi' and 4 'fun' (4 cm); length, 8 'chi' and 2-4 'fun' (24.6-25.2 cm). There were 6 types of metal strips and the length of the nails employed was 1 'chl' (3 cm). Investigation on the differences in the length of the wood Blocks and the shapes of the metal strips will be of interest. Since we surveyed only small portion of the Wood Blocks. the result may be different if entire Wood Blocks were examined. The data acquisition of the entire Wood Blocks will be the basis to the conservation of the Wood Blocks.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.255-263
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• 2015

Biological invasion of alien plants is considered to be one of the most serious threats to biodiversity in riparian zones. The effects of two invasive alien plants, Sicyos angulatus and Paspalum distichum var. indutum, on the flora and community structure of the riparian vegetation were investigated at 22 sites at streams in Korea. Sicyos angulatus has invaded the central Korean Peninsula. This alien plant has caused problems to stream managers because of its aggressive vining growth. It had suppressed native vegetation such as trees, shrubs and tall grasses on bank slope and higher floodplains. Paspalum distichum var. indutum has become more widespread in the southern part of Korea. This invasive plant has shallow rhizomes and creeping, extensively branched stolons. It forms a dense mat over lotic or slowly-flowing water and threatens submerged and short emergent hydrophytes. In order to control the introduction and expansion of alien plants, limitation of artificial disturbances and appropriate alien plant management are needed in riparian areas.

• Applied Microscopy
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• v.28 no.2
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• pp.215-224
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• 1998

To investigate ultrastructural changes on the adrenal glands of the developmental rats, tissues were collected at 20 days of gestation, at birth, 7 days, 15 days and 30 days after birth and studied by electron microscope. In the medulla of adrenal gland of the rat, two types of granules were observed at ultrastructural level. The one were adrenaline $(123\sim200nm)$ and the others were noradrenaline ($177\sim279nm$ of long axis, $124\sim194$ of short axis). Adrenaline granules were characterized by presence of round or spherical with low or moderate electron density. The granules showed a wide lucent or clean halo between the contents and the limiting membrane. On the other hand noradrenaline granules were characterized by the presence of irregular shape with high electron density. This granules showed a wide lucent between the contents and limiting membrane. These two types of granules were co-existed in one cell in the late gestation and at birth, but after that two types of cells were clearly observed. The different sizes and numbers of granules were observed with ages.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.44-52
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• 1996

Sensory properties of cooked rice were affected by the varieties and growing environments of the rice. Moistness, cohesiveness, and adhesiveness of cooked rice were highly and positively correlated each other, whereas firmness was negatively correlated with these attributes. Sixty rice samples which differed in varieties and/or growing environments were divided into four groups based on their textural properties through principal component analysis and cluster analysis. Quality type I showed the highest values for moistness, cohesiveness, and adhesiveness, and the lowest values for firmness of cooked rice. On the other hand, quality type IV showed just the opposite values. There was no significant difference among rice starches in amylose content (P<0.05). A17 (type III) and A09 (type IV) had higher blue values for starch and amylopectin than the other samples (type I and II). On the amylogram, these samples showed lower values for breakdown and higher values for setback than the other samples. Average degree of polymerization, average chain length, and average number of chains for amylose and amylopectin were 597-878 and 2660-3140, 140-230 and 17-19, and 3.1-4.9 and 140-170, respectively.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.412-423
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• 2018

In this study, we investigated the distribution and habitat of Tscherskia triton from 2014 to 2016 in Jeju Island. Nine individuals of T. triton were observed and captured from four habitat sites. Most of the habitats were of the natural and rural type, and urban type coexisted in some of the areas. The natural type of habitat comprised of forests, shrubs, and grasslands. The habitat of T. triton ranged vertically from 102 m in lowland to 742 m in a mountainous area and was not observed in altitude over 1,000 m. Small brooks, dry streams or wetlands were found to be located nearby the habitat of T. triton. The T. triton was distributed mainly in areas with natural vegetation and artificial plantation in company with the upper story vegetation on the ground of intact or incomplete layer structure, or the area with the relatively large distribution of shrubs and long grassland. The presence of roads and forest paths in these habitats suggested that the T. triton can thrive in areas with human disturbance. The designation of Halla Mountain National Park in Jeju Island as a conservation area prevents damage or loss of the habitat due to any artificial development. However, frequent human disturbances occurring in grassland is tolerated by small mammals. Therefore, in order to help T. triton maintain a stable population density, it is essential that various types of the habitat should be conserved in the middle mountain areas and the grasslands in lowlands should be well protected.

• Korean Journal of Child Education & Care
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• v.19 no.1
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• pp.59-73
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• 2019

Objective: The purpose of this study was to investigate the moderating effect of mothers' play support beliefs on the relation between mothers' insecure attachment and children's playfulness. Methods: The research participants of this study include 254 children aged 3 to 5, who attended kindergartens and day care centers located in Seoul, Gyeonggi and Chung-cheong, and their 254 mothers. For data analyses, descriptive statistics, Pearson's correlation and hierarchical multiple regression were conducted using SPSS 23.0 program. Results: First, there was negative association between mothers' insecure attachment and play support beliefs. Social spontaneity and expression of joy were negatively related to mothers' insecure attachment. However, mothers' play support beliefs showed positive associations with children's playfulness, particularly including children's physical spontaneity and expression of joy. In addition, mothers' play support beliefs moderated the relation between mothers' insecure attachment and children's expression of joy. However, the beliefs did not moderate the relation between mothers' insecure attachment and other playfulness traits. Conclusion/Implications: The findings of the present study indicate that mothers' understanding of the importance of play may buffer the adverse effect of mothers' insecure attachment on children's capabilities of expressing their sense of pleasure.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.147-157
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• 2019

This study aimed to evaluate skeletodental characteristics of patient with maxillary lateral incisor agenesis (MLIA) in mixed dentition. It involved the children in early mixed dentition who visited Pusan National University dental hospital for orthodontic purposed and had intact primary canines. 38 children with MLIA and 38 controls with the same chronological age satisfying the inclusion criteria were selected. The craniofacial structures and dental arch dimensions of the MLIA were evaluated using model & cephalometric analysis and compared to controls. The rate of unilateral MLIA was high in male and the rate of bilateral MLIA was high in female. In model analysis, the width / length ratio of maxillary anterior portion of the MLIA group were higher and arch perimeter of the maxilla of the MLIA group were smaller than those of the control group (p = 0.003, 0.04). Cephalometric analysis showed that there were no significant differences in terms of skeletal, dental analysis. In soft tissue profile, nasolabial angle was larger in MLIAs than in controls (p = 0.039). Considering these skeletodental characteristics of MLIA, early diagnosis and proper management is highly recommended to minimize the possibility of functional defect.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.115-125
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• 2021

This study surveyed the population ecology of Acheilognathus chankaensis (Pisces: Acheilognathinae) in the vicinity of the Churyeongcheon (Stream) and Seomjingang (River) in Jeonbuk, Korea, from February 2006 to May 2007. The survey found the habits mainly in the slow-flowing waters having sand, mud, and gravel bottoms. Age groups estimated by the standard length-frequency distribution of the population indicated that the one-year-olds were 30-46 mm long, the two-year-olds were 47-58 mm long, the three-year-olds were 59-68 mm long, and the four-year-olds were longer than 69 mm. The gonadosomatic index (GSI) and the ratio of ovipositor length/standard length were the highest in March (♀: 12.9%, ♂: 5.0%) and in April (46.3%), respectively. The ratio of mature egg diameters that were 1.6 mm was highest in May (13.2%). The comprehensive analysis of spawning characteristics showed that the spawning season was from March to June with water temperatures in 11.5-22.5℃, and the sex ratio of female:male was 1:1.13. The fecundity in the ovaries and the number of mature eggs were 318±174.5 (50~583) and 220±139.2 (50~406), respectively. The size of the mature eggs was 2.04±0.110 mm on the long axis and 1.55±0.100 mm on the short axis for the study period. Gut contents of A. chankaensis were mainly phytoplankton such as the genera Fragilaria, Synedra, Navicular, Cymbella (Bacillariophyceae), and Cosmarium (Chlorophyceae).

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.57-63
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• 2022

On April. 2016, the anadromous icy goby caught at Shinbong-cheon, Tongyeong shi, Gyeongsangnam-do transported to the laboratory of Korea Institute of Ocean Science and Technology (KIOST) and observed spawning behavior and egg development and larvae. In aquarium, males make the nest under stone and waiting female entering. Fertilized eggs attached under the stone in the nest. Male protected the fertilized eggs until hatching. The size of the club-shaped eggs were 3.2~3.4 mm in the major axis and 0.6~0.8 mm in minor axis (n=10). The eyed eggs were hatched after 168 hrs in a range of water temperatures (18.0~20.0℃). The total lengths of newly hatched larvae were 4.1~4.4 mm (n=5) and these larvae had 32~33 (12~13+20) myotomes and transparent oval yolk. Three days after hatching, the pre-larva (4.9 mm in total length) has opening mouth and rectum. Post-larva with 5.2 mm total length have melanophore on air bladder, rectum, base of membranous caudal fin and 9~10 melanophores ventral row on the tail.