• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.53-69
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• 2020

The increase of the impermeable area due to industrialization and urban development distorts the hydrological circulation system and cause serious stream drying phenomena. In order to manage this, it is necessary to develop a technology for impact assessment of stream drying phenomena, which enables quantitative evaluation and prediction. In this study, the cause of streamflow reduction was assessed for dam and weir watersheds in the five major river basins of South Korea by using distributed hydrological model DrySAT-WFT (Drying Stream Assessment Tool and Water Flow Tracking) and GIS time series data. For the modeling, the 5 influencing factors of stream drying phenomena (soil erosion, forest growth, road-river disconnection, groundwater use, urban development) were selected and prepared as GIS-based time series spatial data from 1976 to 2015. The DrySAT-WFT was calibrated and validated from 2005 to 2015 at 8 multipurpose dam watershed (Chungju, Soyang, Andong, Imha, Hapcheon, Seomjin river, Juam, and Yongdam) and 4 gauging stations (Osucheon, Mihocheon, Maruek, and Chogang) respectively. The calibration results showed that the coefficient of determination (R²) was 0.76 in average (0.66 to 0.84) and the Nash-Sutcliffe model efficiency was 0.62 in average (0.52 to 0.72). Based on the 2010s (2006~2015) weather condition for the whole period, the streamflow impact was estimated by applying GIS data for each decade (1980s: 1976~1985, 1990s: 1986~1995, 2000s: 1996~2005, 2010s: 2006~2015). The results showed that the 2010s averaged-wet streamflow (Q95) showed decrease of 4.1~6.3%, the 2010s averaged-normal streamflow (Q185) showed decreased of 6.7~9.1% and the 2010s averaged-drought streamflow (Q355) showed decrease of 8.4~10.4% compared to 1980s streamflows respectively on the whole. During 1975~2015, the increase of groundwater use covered 40.5% contribution and the next was forest growth with 29.0% contribution among the 5 influencing factors.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.261-268
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• 2015

The aim of this study was to examine the effects of high energy diet on growth 26mon, 28mon, and 30mon in Hanwoo at different ages. High energy diet required not only an amount of concentrate on days of fattening periods but also induced cost for the management. We hypothesized that high energy diet was able to reduce a fattening period to reach a certain quality grade. A $2{\times}3$ factorial arrangement (High energy, control vs 26, 28, 30month endpoints) in a completely random design was used to feed 48 Hanwoo steers. Four steers were fed in same pen and 12 pens were used for treatment. Blood was drawn from each steers on every other months during early, middle, and final fattening periods. Over all ADG and feed efficiency were not different between high energy and control diet (P > 0.05). Dry matter intake was induced 30 mo-old early and final fattening periods at high energy diet. Serum glucose concentration were increased (P < 0.05) at 30 and 26month old steers. Marbling scores were greater at 30 month old than 26 and 28 month old Hanwoo steers. Carcass weight of Hanwoo steers were greater at 30 mon-old groups than other groups. These result indicated that high energy diet (+3% TDN) and slaughter endpoint collectively contribute to the observed quality grade compositional differences among three final fattening periods of Hanwoo steers.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.3
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• pp.202-208
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• 2010

Purpose: This study was aimed to evaluate the effect of rhPMP-2 coated implants on alveolar ridge augmentation in dogs. Materials and methods: Six Beagle dogs were used in this study. Six 8.0 mm long anodized surface titanium implants were placed 5 mm into the mandibular alveolar ridge following 6 month of healing period after extraction. Each animal received three implants coated with rhBMP-2 and three uncoated control implants using the randomized split-mouth design. Radiographic examinations were undertaken immediately at implant placement (baseline), at weeks 4 and 8 after implant placement. The amount of bone augmentation was evaluated by measuring the distance from the uppermost point of the coverscrew to the marginal bone. Implant Stability Quotient (ISQ) values were measured immediately at implant placement and 8 weeks after implant placement. For the statistical analysis, Man-Whitney ranksum test and Wilcoxon signed rank test of SPSS 12.0 software were used (P=.05). Results: The BMP group exhibited radiographic vertical bone augmentation about $0.6{\pm}0.7$ mm at 8 weeks later while controls showed bone loss about $0.4{\pm}0.6$ mm. There was significant difference among the rhBMP-2 group and controls in bone level change (P<.05). The ISQ values were significantly higher in the BMP-2 group than the control group at 8 weeks later (P<.05), while there was no significant difference at surgery. Conclusion: Within the limitation of this study, the rhBMP-2 coated on anodized implant could stimulate vertical alveolar bone augmentation, which may increase implant stability significantly on completely healed alveolar ridge.

• Journal of agricultural medicine and community health
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• v.39 no.4
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• pp.240-255
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• 2014

Objective: The purpose of this study was to identify the correlates of bone mineral density of Korean adults. Methods: This study was based on the data from the 2010-2011 Korean National Health and Nutrition Examination Survey (KNHANES, 2010~2011) V. Among 8,473 subjects of the survey, who were adults 19 years old or over with bone mineral density data, the current study excluded those whose data include a missing study variable or the response of 'I don't know', and finally analyzed the data of 5,986 subjects (2,692 males and 3,294 females). This study employed the following statistical methods of analysis: t-test, analysis of variance (ANOVA), and hierarchical multivariate linear regression analysis. Results: In multivariate analysis, in the case of men, the significant associated factors in bone mineral density were age, education level, body mass index (BMI), waist circumference, total muscle mass, exercise, and weight control; in the case of women, the significant associated factors in bone mineral density were age, education level, economic activity, BMI, total muscle mass, exercise, weight control. fat intake, uptake female hormone, menopause, and age of menarche. Conclusion: For both sexes, the strongest modifiable factor in influencing bone mineral density was total muscle mass. Therefore, to prevent osteoporosis and promote health, active health education and interventions such as regular exercise for total muscle mass increase should be implemented from an early growth period.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.93-108
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• 1998

This study investigated science textbooks used from 1906 to 1915 in Korea, which is often neglected in previous researches. By doing so, more practical and specific understanding of the science education during that period can be made. It was based on the historical achieves "School Textbook List"(Vol. $4{\sim}9$) which was published by the Ministry of Education and the Government General of Chosen and other sources. The results and conclusions of the research are as follow; (1) The science textbooks which have been used from 1906 to 1915 in Korea can be categorized into three different tapes of books, either written in Chinese, or in Japanese, or in Korean. The names of science textbooks were Nature Study, Physics, Chemistry, Natural History, Hygienics, Physiology, Zoology, Botany, Astronomy, Physiography, Mineralogy, Geology. These names were much broader than those in curriculum settled by the government and rather correspond to the names of science textbooks in curriculum which settled by private schools. Therefore those science textbooks had been mainly used in private schools. Moreover almost all of the science textbooks published in Korea have started to appear after 1906. Since then many schools were newly opened and the number of students increased. It is possible to say that substantial science education in Korea established after 1906. (2) Science textbooks from 1906 to 1915 printed in Korea were controlled in their use by the Ministry of Education and the Government General of Chosen. They were the main means of government regulations, supported by Private School Ordinance, Regulations for Official Examination of textbooks in 1908 and Law of Publication in 1909. According to the result of official examination, as the time went by under the Japanese ruling of Korea, the increasing number of science textbooks were getting banned. While the science textbooks had enjoyed more freedom than the other textbooks from the control by inspection of the Government General of Chosen, the situation has been significantly changed as Japan started to intensity the control of all kinds of textbooks in Korea. Although there were a lot of copied science textbooks, 62 science textbooks printed in Korea, 72 Japanese science textbooks were used in Korea, and 40 Korean were to be engaged in science education compiling and copying science textbooks. There developments in science textbooks alone suggest that there were enormous amount of potentials in Korean science education at that time. However, all of these effects and progresses were destroyed when the sovereign authority of Korea was lost to Japan in 1910.

• Journal of Radiation Protection and Research
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• v.38 no.2
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• pp.68-77
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• 2013

Derived Investigation levels(DILs) were calculated to protect the workers from the effects of both radiological hazard and chemical toxicity by uranium intake. Investigation Levels(ILs) of committed effective dose of 2 mSv $y^{-1}-6$ mSv $y^{-1}$ and uranium concentration of 0.3 ${\mu}g$ $g^{-1}$ in kidney, based on Korean Nuclaer Safety Act, Korean Occupational Safety and Health Act and current scientific studies of uranium intake were assumed. DILs of radiological hazard and chemical toxicity were then calculated based on the concentration of uranium in air of workplace, the lung monitoring and urine analysis, respectively. As a result, in case of the nuclear fuel fabrication plant where 3.5% enriched uranium is handled, derived investigation level(DIL) for the control of the concentration of uranium in the air of workplace assumed with 15-min acute inhalation was 0.6 mg $m^{-3}$ for all types of uranium. DILs for the control of the average concentration of uranium in air of workplace, assuming an 8-hour workday, were 15.21 ${\mu}g$ $m^{-3}$ of Type F uranium, 0.41-1.23 Bq $m^{-3}$ and 0.13-0.39 Bq $m^{-3}$ for Type M and Type S uranium, respectively. DILs for the lung monitoring assumed with a period of 6-month interval were 0.37-1.11 Bq and 0.39-1.17 Bq in acute and chronic inhalation for Type M, respectively and 0.30- 0.91 Bq and 0.19-0.57 Bq in acute and chronic inhalation for Type S, respectively. Since a detection limit of typical germanium detector for the measurement of 235U activity is 4 Bq, DILs calculated for the lung monitoring were not appropriate. DILs for urine analysis, for which an interval was assumed to be 1 month, were 14.57 ${\mu}g$ $L^{-1}$ based on chemical toxicity after acute inhalation. In addition, acute and chronic inhalation of Type M were calculated 2.85-8.58 ${\mu}g$ $L^{-1}$ and 1.09-3.27 ${\mu}g$ $L^{-1}$ based on the radiological hazard, respectively.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.2
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• pp.131-138
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• 2003

Purpose: We analyzed our malignant peripheral nerve sheath tumor (MPNST) cases to find out their oncologic results following by each treatment modalities. Materials and Methods: Thirty four patients with MPNST were registered in Korea Cancer Center Hospital from Feb. 1986 to Nov. 1996. Seventeen cases were male and 17, female. Average age was 41 years (range 18 to 74). Location of the tumor was as follows; 17 in lower extremity, 11 upper extremity, 4 trunk, and 2 retroperitoneum. Following the AJC classification, stage IA were 2 cases, stage IIA 2, stage IIB 6, stage III 16 and stage IV 8. Twenty six patients took operations and adjuvant chemotherapy and/or radiation therapy, 3 operation only and 3 adjuvant chemotherapy or radiation therapy. Average follow up period was 33.5 months (5.6 to 146.1). Kaplan-Meiyer method was done for survival curve, and log rank test for comparison analysis. Results: Fourteen cases were continuous disease free, 2 no evidence of disease, 2 alive with disease and 14 dead of disease states at final follow up. Actual 5-year and 10-year survival rates were 53.5%, 35.7%. Local recurrence rate after operation was 24.1%. 5-year survival rates of stage I/II/III were 100/85.7/55.9% and 2-year survival rate of stage IV was 14.3% (p=0.04). In 21 cases operated with stage II-III, wide margin (15cases) had 76.0% 5-year survival rate, and marginal or intralesional marigin (6cases) had 40.0%. The actual 5-year survival rate of the group which were done 4 or more cycles chemotherapy (8cases) was 71.4% and the actual 3-year survival rate less than 4cycles chemotherapy (6cases) was 83.3% (p=0.96). In 19 cases operated with stage II-III and which had no radiotherapy, marginal or intralesional margin (5cases) had 3 cases of local recurrences (60.0%), though wide margin (14cases) had 4 cases recurrences (28.6%). There was no local recurrence in 8cases which had pre-or post-operative radiotherapy. Conclusions: Surgical margin is an important factor in local recurrence. Resection margin has a tendency to influence the survival despite insufficient statistical significance. Conventional chemotherapy has no defnite statistical sigficance in the effect on local control and survival. Preoperative and postoperative radiotherapy has some positive effect on local control.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.376-382
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• 2014

This work was conducted to investigate the variation of growth and yield among three generations ($TC_0$, $TC_1$, and $TC_2$) in the field cultivation of virus-free sweetpotato (Ipomoea batatas) plants. Virus-free generations of three cultivars ('Matnami', 'Shinhwangmi', and 'Yeonhwangmi') were cultivated with $75{\times}25cm$ planting density on May 20th, covered with black vinyl film. At 30 days after planting, vine growth in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, and vine length in $TC_0$ showed the highest growth among treatments. At harvesting time after 120 days, vine diameter, number of node, and number of branch in $TC_0$, $TC_1$, and $TC_2$ were more increased than farmer's plant, but were not statistically significant. Fresh weight of shoot in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant, but was not statistically significant among generations or cultivars. Number of tuber per plant and mean weight of tuber in $TC_0$ and $TC_1$ showed significant increasement, but that in $TC_2$ did not show significant difference as compared to the farmer's plant. Weight of tuber per plant in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. Marketable yield, percentage of marketable tuber, and percentage of small tuber (40 to 200g) in $TC_0$, $TC_1$, and $TC_2$ was significantly increased as compared to the farmer's plant. The large tuber over 300g showed the lowest percentage in $TC_0$. Marketable yield in $TC_2$ was significantly decreased as compared to $TC_0$, and was not significantly different as compared to the farmer's plant. Marketable yield in 'Matnami' was highest among cultivars. From this results, Farmers are required to renew every three years to maintain the yield and quality of virus-free plants. However, the exchange period of virus-free plants is desirable to renew every 2 or 3 years according to the degree of virus reinfection.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.275-280
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• 2015

The objective of this study was to investigate the effect of drip irrigation level on soil salinity and growth of broccoli (Brassica oleracea L. var. italica) at the 'Saemangeum Reclaimed Tidal Land' from April to June, 2015. Drip irrigation was conducted at 1.5, 3.0 and $6.0mm{\cdot}day^{-1}$ level for reduction of resalinization in the plastic vinyl house using 10cm spacing drip irrigation tape. At harvesting stage, the average EC of surface soil was $10.9dS{\cdot}m^{-1}$ for $1.5mm{\cdot}day^{-1}$, $11.5dS{\cdot}m^{-1}$ for $3.0mm{\cdot}day^{-1}$ and $5.1dS{\cdot}m^{-1}$ for $6.0mm{\cdot}day^{-1}$ and was significantly reduced by 52~56% in $6.0mm{\cdot}day^{-1}$ treated plot compared to those in 1.5 and $3.0mm{\cdot}day^{-1}$ plots. The fresh bud weights of 1.5, 3.0 and $6.0mm{\cdot}day^{-1}$ treatment plots were 60.9, 129.1 and $371.3g{\cdot}plant^{-1}$, respectively. The estimated soil EC for 50% yield reduction was $7.6dS{\cdot}m^{-1}$ and the desalinization depth by drip irrigation was 30~40cm in soil profile. The total amount of drip irrigation water was estimated to be 422mm and the daily drip irrigation level was $6.0mm{\cdot}day^{-1}$ for the prevention of resalinization during the broccoli growing period at the 'Saemangeum Reclaimed Tidal Land'. Our results suggested that drip irrigation shows effectiveness on the lowering the soil salinity according to the drip irrigation quantity but it needs more research on this study because dynamics of salts in soil can vary with many factors such as soil physico-chemical properties and seasonal climate.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.301-307
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• 2015

High quality transplants are critical for success in crop production. Increasing numbers of growers purchase their transplants from specialized transplant producers instead of growing their own transplants. A drawback of purchasing transplants is the risk of deterioration to transplants during transportation from transplant producers to the growers. This study evaluates the influence of temperature on the quality of grafted tomatoes transplants (Solanum lycopersicum cv. Super Doterang), in order to propose optimum temperature condition for the transportation of grafted tomato transplants. Grafted tomato transplants with visible flower trusses were exposed to different air temperature ($10^{\circ}C$, $25^{\circ}C$, or $40^{\circ}C$) for 2, 4, or 6 hours. After treatment, the NDVI (Normalized Difference Vegetation Index) values of tomato transplants treated at 25 and $40^{\circ}C$ were lower than that at $10^{\circ}C$. The root fresh weight was lowest at $40^{\circ}C$. After transplanting, the transplants that were exposed to the air temperature of $40^{\circ}C$ exhibited chlorosis and blight on lower leaves. The degree of damage on leaves was severer as the high temperature exposure time was longer. The temperature conditions during the transportation also influenced the growth, flowering and fruit set of tomatoes after transplanting. The fruit number and weight of first truss was lowest at $40^{\circ}C$ for 6 hours. Accordingly, it is recommended that the temperature during the transportation should be controlled and kept at the range from 10 to $25^{\circ}C$ even though the period is short (within as six hours) in order to maintain the quality of transplants.