• Development and Reproduction
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• v.5 no.1
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• pp.39-45
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• 2001

Black rockfish Sebastes schlegeli is one of scopaenid fish giving birth to yolk-sac larvae and distributed around the coast of Korea and Japan, and is one of main species which is cultured in Korea. The difffrentiation of thyroid gland and the changes of thyroid hormones (THs) concentrations in the whole body during early development of this species were examined and the relationship between thyroid gland and their growth will be presented. Total length (TL) and body weight (BW) of the larva at the parturition were 6.3${\pm}$0.1 mm and 3.6${\pm}$0.1 mg, respectively. The larvae transformed to juvenile after 30th day after parturition. According to Hoshiai(1977), they had gown into stage Fl (TL 13.2${\pm}$0.9 mm, BW 46.5${\pm}$1.5 mg) at 50th day. The thyroid gland of black rockfish was first observed histologically in hatching larvae in mother fish. The larvae just after parturition have 1${\sim}$3 of the thyroid follicles diffrentiated between basibranchial bone and ventral aorta, at the base of the first gill arch. In this time, thyroid follic1e number (TFN),thyroid follicle diameter (TFD) and thyroid cell height (TCH) were 1.6${\pm}$0.8 pieces/inds., 18.1${\pm}$0.6 ${\mu}$m and 4.1${\pm}$0.2 ${\mu}$m, respectively. TFN and TFD at 50th day were increased to 32.5${\pm}$6.9 pieces/inds. and 41.5${\pm}$1.7 ${\mu}$m, respectively. These results indicate that they are related to the growth of black rockfish during early development. However, TCH indicates that the activity of thyroid gland appearedat special day, eg. 5, 20 and 50th day, suggesting that TCH may have some role in the physiological activity. L-thyroxine (T$_4$)concentration decreased sharply to 10 days after parturition, and at 25th day (metamorphosis stage) increased markedly to 3.44${\pm}$0.93ng/g fish. After this time, T$_4$ concentration decreased at 35th day, but then increasedagain to the highest concentration, 5.63${\pm}$0.70ng/g fish. 3,5,3'-triiodo-L-thyronine (T$_3$) concentration declined sharply from just after pafurition (4.96${\pm}$1.90 ng/g fish) to 5th day (0.30${\pm}$0.07 ng/g fish). However T$_3$ concentration increased markedly to 0.95${\pm}$0.11 ng/g fish at 30th day and then did not significantly change until 45th day, increased also sharply to 1.67${\pm}$0.23 ng/g fish at 50th day.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.118-127
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• 1985

The grain temperature is a crucial factor determining the deterioration rate of stored grain. Therefore, it is used to be predicted in order to evaluate the various stored methods rapidly and inexpensively. In this study, a mathematical model was developed to simulate the temperatures of grain stored in a cylinderical bin. It was formulated for the two dimensional heat transfer by the finite difference method. Then, it was verified statistically using the actual test deta and the predicted. The changes of grain temperature were analyed using the simulated data of one year for a safe stoarge and the following results were obtained: 1. Simulation model developed by the finite difference method was validated with the actual and the predicted grain temperatures and it's result showed that it could predict the grain temperature of storage bin reasonably well. 2. Grain temperature near the wall of storage bin were changed with $6-7^{\circ}C$ higher then average atmospheric temperature from June to September. Therefore, the parts of stored grain near the wall is supposed to be deteriorated fast. 3. When the dimension of bin diameter is about the same as the bed height, the changes of grain temperature of radial direction was higher than the verticals. 4. The predicted temperature showed that the grain temperature of which were from the end of April to mid October were higher than the safe storage limit at Yusung, Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.166-172
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• 2002

The top shell, Omphalius pfeifferi capenteri meat vacuum-packed in can (diameter$\times$height, 74.1mm$\times$50.7mm) were heated at 115$^{\circ}C$ up to $F_0$ values of 5 min, 10 min, 15 min and 20 min, and the changes in food components were studied. After 14 days storage at 37$^{\circ}C$ and 55$^{\circ}C$, no growth of microorganism and panelling were recognized from the canned meats which were sterlized at 115$^{\circ}C$ with $F_0$ value of S min and over. In the case of proximate composition of the canned meats, the moisture content decreased with the increase of $F_0$ value, while crude protein increased. The increase of volatile basic nitrogen content, pH and degree of browning and the decrease of mineral, total amino acid, free amino acid, trimethylamine oxide, total creatinine contents and yields were observed during thermal processing, In sensory evaluation on color, texture and taste in the canned meats, no significant difference was observed among a boiled sample and the canned meats heated at re value of 10 min and below. But, in the canned meats heated at $F_0$ value of over 15 min, its sensory scores decreased with the increase of $F_0$ value. From these results, the reasonable $F_0$ value for preparation of the heat-treated top shell meats was in the range of 5$\~$10 min.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.237-246
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• 2020

Recently, as high resolution satellites data have been serviced, frequent DSM (Digital Surface Model) generation over urban areas has been possible. In addition, it is possible to detect changes using a high-resolution DSM at building level such that various methods of building change detection using DSM have been studied. In order to detect building changes using DSM, we need to generate a DSM using a stereo satellite image. The change detection method using D-DSM (Differential DSM) uses the elevation difference between two DSMs of different dates. The D-DSM method has difficulty in applying a precise vertical threshold, because between the two DSMs may have elevation errors. In this study, we focus on the urban structure change detection using D-nDSM (Differential nDSM) based on nDSM (Normalized DSM) that expresses only the height of the structures or buildings without terrain elevation. In addition, we attempted to reduce noise using a morphological filtering. Also, in order to improve the roadside buildings extraction precision, we exploited the urban road network extraction from nDSM. Experiments were conducted for high-resolution stereo satellite images of two periods. The experimental results were compared for D-DSM, D-nDSM, and D-nDSM with road extraction methods. The D-DSM method showed the accuracy of about 30% to 55% depending on the vertical threshold and the D-nDSM approaches achieved 59% and 77.9% without and with the morphological filtering, respectively. Finally, the D-nDSM with the road extraction method showed 87.2% of change detection accuracy.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.629-636
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• 2021

The purpose of this study was to identify the effects of mammo pad made of different kinds of materials on the reduced inconvenience and compression pains of patients to examine plausible interchangeability of existing pads made of single kind of material, and to examine the changes in pains of patients taking mammography and various factors therein. The high-hardness and highly-elastic mammo pressure pads, capable of replacing existing mammo pad of "H" company, were manufactured, and the display quality of mammography obtained from respective mammo pad were compared to each other to appraise the availability of manufactured mammo pad. In addition, 200 patients, who came to a general hospital in Seoul, were selected as subjects for the survey employing a questionnaire which was distributed to the subjects from December 2018 to March 2020 to identify the factors involved with the mammo pad of patients while taking mammography. The results of mammography obtained from both of the existing and newly manufactured mammo pad revealed appropriate display qualities fell within the range of clinical criteria. Besides, the factors associated with changing compression pains of patients taking mammography were analyzed wherefrom the general factors in the following order of age, height, and BMI index appeared, while the experiential and female factors appeared as in the following order: presence of menstruation, experience of child-birth, experience of breast feeding, menopause, grade of breast, shape of breast, and experience of mammography. In conclusion, the following factors comprising the age, experience of breast feeding, experience of mammography, and menopause rendered approximately 54% of power of explaining the degree of changing pains during mammography. Regarding the changes in compression pains while taking mammography, the increasing experience of mammography of patients rendered approximately 0.26 times more at the intermediate range of compression pains and approximately 0.14 times more at the range of severe pains.

• Journal of Environmental Impact Assessment
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• v.30 no.3
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• pp.141-154
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• 2021

In this study, the effect of the restoration of Yaksa stream and the construction of an apartment complex by the urban renewal project in the Yaksa district of Chuncheon on air quality in the surrounding area was evaluated using computational fluid dynamics (CFD) model simulations. In orderto compare the impact of the project, wind and pollutant concentration fields were simulated using topographic data in 2011 and 2017, which stand for the periods before and after the urban renewal project, respectively. In the numerical experiments, the scenarios were set to analyze the effect of the construction of the apartment complex and the effect of stream restoration. Wind direction and wind speed data obtained from the Chuncheon Automated Synoptic Observing System (ASOS) were used as the inflow boundary conditions, and the simulation results were weighted according to the frequencies of the eight-directional inflow wind directions. The changes in wind speed and NO_X concentration distribution according to the changes in building and terrain between scenarios were compared. As a result, the concentration of NO_X emitted from the surrounding roads increased by the construction of the apartment complex, and the magnitude of the increase was reduced as the result of including the effect of stream restoration. The concentration of NO_X decreased around the restored stream, while the concentration increased significantly around the constructed apartment complex. The increase in the concentration of NO_X around the apartment complex was more pronounced in the place located in the rear of the wind direction to the apartment complex, and the effect remains up to the height of the building. In conclusion, it was confirmed that the relative arrangement of apartment complex construction and stream restoration in relation to the main wind direction of the target area was one of the major factors in determining the surrounding air quality.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.46-58
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• 2022

This study analyzed the documentation trend of garden components such as plants, infrastructure, unit facilities, and structures, based on 188 measurement drawings of 94 old houses in a report on the documentation of the national folklore cultural heritage. The findings are as follows. First, it was found that plants and structures continuously appeared as the subject of measurement drawings, while infrastructure was often omitted. It was confirmed that unit facilities, which are smaller than other components, were frequently excluded from the documentation subject as well due to frequent changes such as movement, loss, and expansion. Second, the level of expression in measurement drawings showed different aspects for each component. The unit facilities showed a large change over time with respect to the level of documentation, and the level of documentation was somewhat polarized, particularly toward the latter stage. This suggests that the level of documenting the drawings limited to specific facilities improved, but the overall level of drawings did not improve, such as a lack of diversification of expression techniques suitable for various unit facilities. On the other hand, it was confirmed that the level of documenting the drawings for plants, infrastructure and structures did not change to a significant degree, implying that no improvements were made to the expression of components. Third, as for the technique of detailed expression, in the case of plants, vegetation status was prepared without distinction of old or protected trees that have historical value. Above all, there was no record of the vegetation structure that could help grasp the vegetation landscape of the outer area. As for the infrastructure, there was no consistent expression technique to systematically convey topographic changes such as the height and slope of the land. In addition, since there was no subtype classification defined for unit facilities and structures, there was no subject or method of documentation. This study is meaningful in that it expanded the category of documentation, which has been concentrated on buildings in old houses, to gardens, and called attention to the need for documenting the gardens for the preservation and management of old houses as an integration of the building and outer area.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.222-238
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• 2024

Coniferous species in subalpine ecosystems are known to be highly sensitive to climate change. Therefore, it is becoming increasingly important to monitor community and population dynamics. This study monitored 37 plots within the distribution area of Abies koreana on Mt. Jirisan for a period of eight years. We analyzed the importance value, density of living stems, mortality rate, recruitment rate, basal area, DBH (diameter of breast height) class distribution, and tree health status. Our results showed changes in the importance value based on the tree stratum, with A. koreana decreasing by 3.6% and Tripterygium regelii increasing by 2.5% in the tree layer. Between 2015 and 2023, there were 149 dead trees/ha (17.99% mortality rate) and 12 living trees/ha (1.02% recruitment rate) of A. koreana. The decrease in basal area was attributed to a decrease in the number of living trees. Tree mortality occurred in all DBH classes, with a particularly high decline in the <10 cm class (65 trees/ha reduced). In terms of changes in tree health status, the population of alive standing (AS) type trees, initially consisting of 539 trees/ha, has been transformed into alive standing (AS), alive lean (AL), and death standing (DS), accounting for 69.7%, 0.5%, and 13.8%, respectively. Meanwhile, DS-type trees have transitioned into dead broken (DB) and dead fallen (DF) types. This phenomenon is believed to be caused by strong winds in the subalpine region that pull up the rootlets from the soil. Further research on this finding is recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.17
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• pp.115-133
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• 1974

This study was done on the metabolism of chemical components during the seed development of ginseng. The changes of the chemical components were inspected in the following periods: from the early stage of flower organ formation to flowering time, from the early stage of fruiting to maturity, during the moisture stratification before sowing. From flower bud forming stage to meiosis stage, the changes in the fresh weight, dry weight, contents of carbohydrates, and contents of nitrogen compounds were slight while the content of TCA soluble phosphorus and especially the content of organic phosphorus increased markedly. From meiosis stage to microspore stage the fresh and dry weights increase greatly. Also, the total nitrogen content increases in this period. Insolub]e nitrogen was 62-70% of the total nitrogen content; the increase of insoluble nitrogen seems to have resulted form the synthesis of protein. The content of soluble sugar (reducing and non-reducing sugar) increases greatly but there was no observable increase in starch content. In this same period, TCA soluble phosphorus reached the maximum level of 85.4% of the total phosphorus. TCA insoluble phosphorus remained at the minimum content level of 14.6%. After the pollen maturation stage and during the flowering period the dry weight increased markedly and insolub]e nitrogen also increased to the level of 67% of the total nitrogen content. Also in this stage, the organic phosphorus content decreased and was found in lesser amounts than inorganic phosphorus. A rapid increase in the starch content was also observed at this stage. In the first three weeks after fruiting the ginseng fruit grows rapidly. Ninety percent of the fresh weight of ripened ginseng seed is obtained in this period. Also, total nitrogen content increased by seven times. As the fruits ripened, insoluble nitrogen increased from 65% of the total nitrogen to 80% while soluble nitrogen decreased from 35% to 20%. By the beginning of the red-ripening period, the total phosphoric acid content increased by eight times and was at its peak. In this same period, TCA soluble phosphorus was 90% of total phosphorus content and organic phosphorus had increased by 29 times. Lipid-phosphorus, nucleic acid-phosphorus and protein-phosphorus also increased during this stage. The rate of increase in carbohydrates was similar to the rate of increase in fresh weight and it was observed at its highest point three weeks after fruiting. Soluble sugar content was also highest at this time; it begins to decrease after the first three weeks. At the red-ripening stage, soluble sugar content increased again slightly, but never reached its previous level. The level of crude starch increased gradually reaching its height, 2.36% of total dry weight, a week before red-ripening, but compared with the content level of other soluble sugars crude starch content was always low. When the seeds ripened completely, more than 80% of the soluble sugar was non-reducing sugar, indicating that sucrose is the main reserve material of carbohydrates in ginseng seeds. Since endosperm of the ripened ginseng seeds contain more than 60% lipids, lipids can be said to be the most abundant reserve material in ginseng seeds; they are more abundant than carbohydrates, protein, or any other component. During the moisture stratification, ginseng seeds absorb quantities of water. Lipids, protein and starch stored in the seeds become soluble by hydrolysis and the contents of sugar, inorganic phosphorus, phospho-lipid, nucleic acid-phosphorus, protein phosphorus, and soluble nitrogen increase. By sowing time, the middle of November, embryo of the seeds grows to 4.2-4.7mm and the water content of the seeds amounts to 50-60% of the total seed weight. Also, by this time, much budding material has been accumulated. On the other hand, dry stored ginseng seeds undergo some changes. The water content of the seeds decreases to 5% and there is an observable change in the carbohydraes but the content of lipid and nitrogen compounds did not change as much as carbohydrates.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.278-283
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• 2003

This study was carried out to examine the nitrogen removal rate of a subsurface-flow treatment wetland system which was constructed on floodplain of the Kwangju River from May to June 2001. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm in depth was filled with crushed granite with about $15{\sim}30\;mm$ in diameter and a middle layer of 10cm in depth had pea pebbles with about 10 mm in diameter. An upper layer of 5 cm in depth contained course sand. Reeds (Phragmites australis) were transplanted on the surface of the system. They were dug out of natural wetlands and stems were cut at about 40 cm height from their bottom ends. Water of the Kwangju River flowed into it via a pipe by gravity flow and its effluent was funneled back into the river. The height of reed stems was 44.2 cm in July 2001 and 75.3cm in September 2001. The number of stems was increased from $80\;stems/m^2$ in July 2001 to $136\;stems/m^2$ in September 2001. Volume and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged 40.0 and $39.2\;m^3/day$, respectively. Hydraulic detention time was about 1.5 days. Average nitrogen uptake by reeds was $69.31\;N\;mg/m^2/day$. Removal rate of $NO_3-N$, $NH_3-N$, T-N averaged 195.58, 53.65, and $628.44\;mg/m^2/day$, respectively. Changes of $NO_3-N$ and $NH_3-N$ abatement rates were closely related to those of wetland temperatures. The lower removal rate of nitrogen species compared with that of subsurface-flow wetlands operating in North America could be attributed to the initial stage of the system and inclusion of two cold months into the six-month monitoring period. Increase of standing density of reeds within a few years will develop both root zones suitable for the nitrification of ammonia and surface layer substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increment in the nitrogen retention rate.