• Journal of radiological science and technology
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• v.30 no.4
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• pp.381-389
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• 2007

The purpose of this study is investigation of radiation dose in CT scan. Data were collected from various references and organizations. Doses measured by CT scanners of each medical organization were analyzed and they were calculated through the examination protocol. The results are as follows : 1. $CTDI_W$ value per 100mAs measured by Head Phantom was the highest in <4-slice MDCT scanner> of 24.20 mGy. $CTDI_W$ values were significantly different among scanner generations(p < 0.01). 2. $CTDI_W$ value per 100 mAs measured using body phantom was the highest in <4-slice MDCT scanner> of 13.58 mGy and the $CTDI_W$ values were significantly different among scanner generations(p < 0.01). 3. When contrast medium was not used, the highest scanner was <16 slice MDCT> of $818.83\;mGy{\codt}cm$ in exposure dose in brain scan(p < 0.05). When the contrast medium was used, the highest scanner was <4 slice MDCT> and its average was $1,460.77\;mGy{\cdot}cm$(p < 0.1). 4. When the contrast medium was not used, the highest scanner was <16-slice MDCT> of $521.63\;mGy{\cdot}cm$ on average in terms of the exposure dose in chest inspection(p<0.05). when the contrast medium was used, the highest scanner was found in 8 slice MDCT scanner and its average was $1,174.70\;mGy{\cdot}cm$. There was no statistically significant difference among scanners. 5. When the contrast medium was not used, the highest scanner was <16-slice MDCT> and its average was $856.27\;mGy{\cdot}cm$ in exposure dose on the abdomen-pelvis(p<0.05). when the contrast medium was used, the highest scanner was <16-slice MDCT> and its average was $1,720.64\;mGy{\cdot}cm$ on average (p < 0.05). 6. When the contrast medium was not used, the highest scanner was <8-slice MDCT> and its average was $612.07\;mGy{\cdot}cm$ in exposure dose in liver inspection(p < 0.05). when the contrast medium was used, the highest scanner was <8-slice MDCT scanner> and its average was $2,197.93\;mGy{\cdot}cm$ in exposure dose(p < 0.1). seventy six point two percent of medical facilities were in risk of radiation exposure while the number of phase was three to four times in their dose inspection of contrast medium.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.283-289
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• 1986

To establish a suitability grouping system of paddy soils for multiple cropping of rice with other upland crops, the study was carried out after a few basic experiments. In succession to the results on basic experiment prior, the suitability system proposed and the results of application mentioned in this report were summarized as follows; 1. The factors of soil properties in the system were productivities represented by soil texture and drainage class, as well as salinity of surface and sub-soil pH of chemical properties were considered together with slope, warmth index, ground water table, parent materials etc. of soil physical or environmental conditions. The weights of the factors were combined with multiplicatively and additively so as the total marks of ideal soil to be 100. The system was composed with 5 suitability classes; over 91 mark is class I, under 60 mark class V, and each 10 point interval between classes. The limiting factors "P" (in the case that Physical properties or Productivity marks under 24), "S" (Surface slope less than 15) and "C" (Chemical condition below 15) etc. were appended up to two kinds to the classes except a part of soils in class I. 2. The areas where the warmth index exceed 110 in Yeongnam were 19% for class I, 22.7% for class II, 44.7% for class III, 11.5% for class IV, and 2.1% for class V. The rates in class I and II were slightly more than those of the whole country. 3. The points of each soil gained by the system had a positive correlation ($r=.922^{**}$) with the potential productivities.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.661-676
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• 2017

This study suggests a new method not only to produce the 1 km-resolution seasonal prediction but also to improve the seasonal prediction skill of temperature over South Korea. This method consists of four stages of experiments. The first stage, EXP1, is a low-resolution seasonal prediction of temperature obtained from Pusan National University Coupled General Circulation Model, and EXP2 is to produce 1 km-resolution seasonal prediction of temperature over South Korea by applying statistical downscaling to the results of EXP1. EXP3 is a seasonal prediction which considers the effect of temperature changes according to the altitude on the result of EXP2. Here, we use altitude information from ASTER GDEM, satellite observation. EXP4 is a bias corrected seasonal prediction using genetic algorithm in EXP3. EXP1 and EXP2 show poorer prediction skill than other experiments because the topographical characteristic of South Korea is not considered at all. Especially, the prediction skills of two experiments are lower at the high altitude observation site. On the other hand, EXP3 and EXP4 applying the high resolution elevation data based on remote sensing have higher prediction skill than other experiments by effectively reflecting the topographical characteristics such as temperature decrease as altitude increases. In addition, EXP4 reduced the systematic bias of seasonal prediction using genetic algorithm shows the superior performance for temporal variability such as temporal correlation, normalized standard deviation, hit rate and false alarm rate. It means that the method proposed in this study can produces high-resolution and high-quality seasonal prediction effectively.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.413-425
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• 2017

This manuscript describes the relationship between climate change and forest growth, forest species, carbon stocks, and tree mortality. 1) In the aspect of forest growth, the growth of major coniferous species, including Pinus densiflora, had a negative correlation with temperature. On the other hand, major deciduous oak species, including Quercus variabilis and Quercus mongolica, had a positive correlation with temperature. 2) When considered in the aspect of the forest species distribution, various models commonly showed a decrease in the distribution of coniferous species and an increase in oak species due to climate change in the medium to long term. 3) From the carbon stock perspective, there was a difference in the estimation according to the status of forest management. Most of Korean forests will mature to become over-matured forest after year 2030 and are estimated to produce approximately 410 million ton forest biomass until 2090 with the current cutting regulations for sustainable forest management announced by the Korean Forest Service. 4) In the forest mortality, the mortality rate of the major coniferous species showed a clear tendency to increase higher temperatures while it decreased for the oak species with no verification of statistical significance. Moreover, the mortality of the subalpine coniferous species was projected to progress rapidly. considering the overall impacts described above, there should be a management strategy for coniferous species that are relatively vulnerable to climate change. Moreover, a sustainable forest plan in the aspect of ecosystem services, carbon sequestration and storage, which is linked to global issues such as Sustainable Development Goals, ecosystem services and negative emission.

• Journal of Embryo Transfer
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• v.20 no.1
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• pp.25-33
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• 2005

This study is a part of research that development of effective genetic resources preservation system using the in vitro spermatogenesis, in vitro insemination and culture system. We aimed for establishment of in vitro culture system with in vitro activated porcine oocytes. The porcine oocytes were matured for 48 hours in $TCM199+10\%$ FCS and activated with $7\%$ ethanol. The activated oocytes were cultured for 7 days in $TCM199+10\%$ FCS or $NCSU23+0.4\%$ BSA medium. The activated oocytes were not developed to the blastocyst stage in $TCM199+10\%$ FCS medium. However in $NCSU23+0.4\%$ medium, those were developed to blastocyst with $3\%$ of treated oocytes. We extended maturation duration of porcine follicular oocytes fur 48, 52, 56, 60, 64, 68, and 72 hours and activated with $7\%$ ethanol and cultured using $NCSU23+0.4\%$ BSA medium. The six percents of activated oocytes were developed to blastocyst in 48 hours and $10\%$ in 52 hours with comparatively low rates suggested to be not fully activated by regenerated MPF. Maturation durations from 56 hours to 68 hours supported to develop upto $11.9\~18.3\%$ of blastocysts. However the developmental rate was declined to $7.2\%$ at 72 hours of maturation duration because of cytoplasmic deterioration. The assumed time window for activation will be $56\~68$ hours of maturation duration. When the matured oocytes were activated with electric pulse of 1, 1.2, 1.4, 1.6, 1.8 and 2.0kV/cm for $80{\mu}s$, although appling the electric current once was not enough for activation, appling twice with 1.6kV/cm for $80{\mu}s$ was shown the highest developmental rate with $11.3\%$. When those were compared with activating methods, $15.7%$ of blastocyst rate was obtained in the $7\%$ ethanol. That was higher than those in electric pulse with $9.5\%$ and calcium ionophore method with $5.8\%$. In this experimental condition, the $7\%$ ethanol treatment was the most effective method for activating porcine oocytes.

• Journal of Aquaculture
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• v.6 no.1
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• pp.29-46
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• 1993

In order to determine the optimum digestible energy to protein (DE/P) ratio in diets for Korean rockfish, Sebastes schlegeli, $45\%$ and $40\%$ protein diets with graded levels of DE/P ratio were fed to average 36g and 80g fish, respectively. The DE/P ratios in the $45\%$ protein diets ranged from 7.4 to 10.0 kcal/g protein, while those in the $40\%$ protein diets varied between 7.5 and 8.9 kcal/g protein. Both in the $45\%$ and $40\%$ protein diets, the changes in the DE/P ratios did not affect either the daily weight gain or the feed efficiency. However daily protein retention, daily energy retention, nutrient utilization and chemical composition in carcass varied depending on the DE/P ratios. Thus based on these parameters as criteria, the optimum DE/P ratio for both the $40\%$ and $45\%$ protein diets, estimated to be about 8 kcal/g protein. DE/P ratios more than 8 kcal/g protein, led to the deposition of a large amount of body fat, especially in the viscera. Any protein-sparing effect was not observed with the increase of the energy content in the diets. Apparent digestibility coefficients determined by the indirect method, using $Cr_2O_3$ as an indicator, were around $90,\;98\%\;and\;70\%$, for protein, lipid and digestible carbohydrate respectively, without any distinct differences between the diets.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.33-49
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• 2016

The study area, located in Sinam-ri, Ulsan, in the southeastern part of the Korean Peninsula, is mainly composed of hornblende granite (ca. 65 Ma). Fracturing and reactivation of a fault striking ENE-WSW was strongly controlled by the intrusion of a mafic dyke (ca. 44 Ma), which behaves as a discontinuity in the mechanically homogeneous pluton, increasing the instability of the basement in this area. A geometric and kinematic study undertaken to interpret the faults and fractures was performed in a trench excavated almost perpendicular to the orientation of the dyke. The analysis of structural elements, such as dykes, veins, and faults, is used to infer the deformation history and to determine the paleostress orientations at the time of formation of the structures. The deformation history established based on this analysis is as follows: (1) NNE-SSW, E-W, ENE-WSW, and NE-SW trending fractures had already developed in the pluton before dyke intrusion; (2) felsic dykes intruded under conditions of σ_Hmax oriented N-S and σ_Hmin oriented E-W; (3) mafic dykes intruded under conditions of σ_Hmax oriented E-W and σ_Hmin oriented N-S; (4) dextral reactivation of the main fault associated with the development of hydrothermal quartz veins under conditions of σ_Hmax oriented E-W and σ_Hmin oriented N-S; (5) sinistral reactivation of the main fault and high-angle normal faults under conditions of σ_Hmax oriented NE-SW and σ_Hmin oriented NW-SE; and (6) dextral reactivation of the main fault and NE-SW low-angle reverse faults under conditions of σ_Hmax oriented NW-SE and σ_Hmin oriented NE-SW. These results are consistent with the tectonic history of the Pohang-Ulsan block in the southeastern part of the Korean Peninsula, and indicates the tectonic deformation of the southern area of the Ulsan fault bounded by Yangsan fault was analogous to that of the Pohang-Ulsan area from the Cenozoic. This work greatly aids the selection of sites for critical facilities to prevent potential earthquake hazards in this area.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.77-93
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• 2000

Field survey on the spatio-temporal distribution of water quality and chlorophyll a concentration, and the environmental factors on the variation of phytoplankton biomass were carried out at the 23 stations for four seasons in the Shiahae, southwestern coast of Korean Peninsula from February to October in 1995. I made an analysis on biological factor as chlorophyll a concentration as well as environmental factors such as water temperature, salinity and nutrients; ammonia, nitrite, nitrate, dissolved inorganic nitrogen, phosphate, N/P ratio, silicate and Si/P ratio. The waters in the Shiahae were not stratified due to the tidal mixing and high velocity of tidal current. And the high productivity in photic layer were supported by high nutrients concentration from freshwater on lands and bottom waters The low depth of transparency in the Shiahae had a bad influence upon primary production and marine biology. In Shiahae had a sufficient nutrients for primary production during a year. Especially dissolved inorganic nitrogen and silicate were high, the other side, phosphate was low. The source of nutrients in summer and silicate supply depend on input of freshwater from lands, the other side, dissolved inorganic nitrogen and phosphate were depend on rather supplied from bottom layer by the mixing and input of seawater from outside than input of freshwater from lands. Phosphate seemed to become a limiting nutrient for the primary production at all area of Shiahae in winter and at the northern parts in other seasons. However, dissolved inorganic nitrogen seemed to do it at the southern parts in other seasons except winter. Silicate didn't become a limiting nutrient for diatoms in Shiahae. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, it was controlled by the combination of the several environmental factors, especially of nitrogen, phosphorus and the physical factors such as light intensity. [Spatio-temporal distribution, Seasonal fluctuation, Nnutrients, Chlorophyll a, Environmental factors, Nutrient source, Limiting Nutrient, Light, Shiahae] .

• Journal of Nutrition and Health
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• v.16 no.3
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• pp.209-215
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• 1983

In high sodium societies, the incidence in blood pressure with childhood growth is more abrupt than the rate of rise in low sodium populations. Thus, it appears that a lower level of dietary sodium intake is required to correct established hypertension and to prevent its appearance In present work, an investigation was made to estimate the correlation between urinary sodium, potassium and creatinine excretion, weight, height, upper arm circumference, blood pressures and the number of heart rate. Sixty- four children aged 12-16 years (41 boys and 23 girls) were measured. Twenty -four-hour urinary sodium and potassium excretion averaged 132.8 mEq and 42.1 mEq in boys, 126.4 mEq and 41.3 mEq in girls. Twenty- four -hour urinary creatinine excretion averaged 795.7 mg and 744.3mg in boys and girls, respectively. Systolic and diastolic blood pressure were 117.6mmHg and 49.7mmHg in boys, 95.5mmHg and 58.2mmHg in girls. Systolic blood pressure correlated positively weight, height and urinary creatinine but diastolic blood pressure correlated positively with upper arm circumference and negatively with urinary potassium. It was concluded that urinary sodium does not explain the blood pressure.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.340-356
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• 2018

Purpose: This study was conducted to develop a nutrition quotient (NQ) to assess overall dietary quality and food behaviors of Korean adults. Methods: The NQ was developed in three steps: item generation, item reduction, and validation. Candidate items of the NQ checklist were derived from a systematic literature review, expert in-depth interviews, statistical analyses of the Korea National Health and Nutrition Examination Survey (2010 ~ 2013) data, and national nutrition policies and recommendations. A total of 368 adults (19 ~ 64 years) participated in a one-day dietary record survey and responded to 43 items in the food behavior checklist. Pearson's correlation coefficients between responses to the checklist items and nutritional intake status of the adults were calculated. Item reduction was performed, and 24 items were selected for a nationwide survey. A total of 1,053 nationwide adult subjects completed the checklist questionnaires. Exploratory and confirmatory factor analyses were performed to develop a final NQ model. Results: The 21 checklist items were used as final items for NQ. Checklist items were composed of four factors: nutrition balance (seven items), food diversity (three items), moderation for the amount of food intake (six items), and dietary behavior (five items). The four-factor structure accounted for 41.8% of the total variance. Indicator tests of the NQ model suggested an adequate model fit (GRI = 0.9693, adjusted GFI = 0.9617, RMR = 0.0054, SRMR = 0.0897, p < 0.05), and item loadings were significant for all subscales. Standardized path coefficients were used as weights of the items. The NQ and four-factor scores were calculated according to the obtained weights of the questionnaire items. Conclusion: NQ for adults would be a useful tool for assessing adult dietary quality and food behavior. Further investigations of adult NQ are needed to reflect changes in their food behavior, environment, and prevalence of chronic diseases.