• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.337-337
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• 2017

Accurate and optimal water supply to cereal crop is critical in growing stalks and producing maximum yields. Excessive soil moisture may cause nutrient deficiencies and oxygen deficiency. Excessive soil water during crop growth stages results in decrease of yields. In Korea, the largest agricultural lands are paddy fields. Recently, upland crops are cultivated in paddy field soils to reduce overproduced rice in Korea. In order to success this policy, it is necessary to fully understand crop response to excessive soil moisture condition from paddy field soils. Adzuki bean is one of major legumes which provide protein in daily diet. Adzuki bean has been well know its weakness to excessive soil moisture condition, In order to obtain optimal yields of adzuki bean from paddy field cultivation, it is necessary to understand response of adzuki bean under different soil moisture conditions. This study investigated characteristics of growths, yields and response degree of water stress from adzuki bean. Three cultivars were selected for this study; Chungju, Hongeon, and Arari. All adzuki beans were cultivated in a paddy field which was divided into three sections with different soil moistures. The paddy field was located in Milyang, Gyeongsangnam during 2016. One section of the paddy field had the greatest average soil moisture content as 35.1% during adzuki bean cultivation (very poor). The second greatest soil moisture section had 32.6% (somewhat poor) and the smallest soil moisture section had 28.9% of soil moisture (somewhat well). During cultivation of three cultivar adzuki beans, soil moisture contents and groundwater levels were monitored. All the characteristics of growth and yield components were measured; height, thickness, 100 seed weights etc. Stress index values were calculated by Stress Day Index (SDI). All cultivars had the greatest yields from somewhat well section. Chungju had the greatest yields throughout all three sections compared to other cultivars. Chungju had 81% greater yield than Hongeon which had the smallest yield from somewhat well section. Arari set in middle from all sections. However there was no significant differences yields from very poor and somewhat poor sections. Leaf SPAD values tended to decrease and stable carbon isotope values increased as soil moisture increased. However, Chungju had no difference across different soil moistures in SPAD and stable carbon isotope values, while Hongeon had the greatest differences across sections. These trends followed by SDI values. Chungju had the smallest SDI values compared to other cultivars, which meant that Chungju was the strongest tolerance against excessive soil moisture than other cultivars. All three cultivars showed severe decrease of yields from very poor and somewhat poor sections. Arari and Hongeon showed great decrease from somewhat well section compared to yields from upland soil. These two cultivars may not be proper cultivating in paddy fields. In conclusion, adzuki bean is very sensitive to soil moisture condition and detailed soil managements are required to obtain optimal yields of adzuki bean from paddy field cultivation.

• Progress in Medical Physics
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• v.16 no.4
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• pp.176-182
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• 2005

Stereotactic radiosurgery (SRS) is a technique to deliver a high dose to a target region and a low dose to a critical organ through only one or a few irradiation. The SRS must be planned exactly. Currently the surgery plan is peformed by trial and error method. There are many questions about the reliability and reproducibility of the plan result. This study Improve each step of the Oh's method based on heuristic target shaping to obtain the better result. The target was reconstructed using cylinders with same height and the neighbored cylinders were combined according to the difference of each center and diameter. Then, spheres were packed within each cylinders by the packing rules. Two virtual targets were used to compare this method with Oh's method. As a result, the numbers of isocenter were successfully reduced - more than $35\%$ and $26\%$ - without serious differences of proscription isodose to tumour volume ratio (PITV) and maximum dose to proscription dose ratio (MDPD). This technique using cylinder piling and sphere packing will be a helpful tool to planner in stereotactic radiosurgery.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.49-54
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• 2000

It is important to identify modifiable risk factors for breast cancer, because the breast cancer is one of the major causs of mortality among women. Some reported that obesity is a risk factor for breast cancer, but the results are not constant. Many risk factors are related to the duration of estrogenic stimulation of the breast. In general, early menarche and late menopause are positive risk factors. Human breast cancer has different characteristics according to the status of menopause(premenopause and postmenopause). In premenopausal women, about 60% of circulating estrogen is from the ovaries in the form of estradiol, and the remaining 40% is estrogen formed primarily in the adipose(fat) tissue via aromatization of androstenedion from the adrenal glands. After menopause this adipose cell production of estrone is the main source of estrogens and the level of estrone is maintained approximately at premenopausal levels. This study was undertaken to determine the role of body size and body mass index by status of menopause in development of breast cancer using retrospective case/control study. From March 1991 to February 1997 at the Wonkwang University Hospital, the breast cancer cases(n=72) and controls(n=86) were selected. By statistical analysis method, regression analysis, paired T-test and multiple logistic regression were done to estimate the influenced factors same as height, weight, BMI, age at menarche and age at menopause. The following results were obtained : 1. In premenopausal women, age at menarche was showed comparatively high correlation coefficients and BMI was described prominently highly in postmenopause. 2. At the results of multiple regression analysis, age at monarch, BMI and weight were showed as significant variables. In this method, critical factor ($R^2$) was 0.054. 3. Paired samples T-test was undertaken to test mean difference between two groups of cases and controls. The result of test performance showed a significant difference. 4. In comparison with women whose weight less than 50 kg, the ORs for the upper 5th group was 1.82(95% confidence interval). The heaviest women had a higher risk(OR=1.14, 95% confidence interval $1.12{\sim}1.31$, p=0.005). Higher body mass index was significantly associated with increased risk of premenopausal breast cancer (OR=1.01, 95% confidence interval $1.08{\sim}l.18$, p=0.05).

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.483-497
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• 2016

Unmanned Aerial Vehicle (UAV) imagery are being assessed for analyzing within field spatial variability for agricultural precision management, because UAV imagery may be acquired quickly during critical periods of rapid crop growth. This study refers to the derivation of barley and wheat growth prediction equation by using UAV derived vegetation index. UAV imagery was taken on the test plots six times from late February to late June during the barley and wheat growing season. The field spectral reflectance during growing period for the 5 variety (Keunal-bori, Huinchalssal-bori, Saechalssal-bori, Keumkang and Jopum) were measured using ground spectroradiometer and three growth parameters, including plant height, shoot dry weight and number of tiller were investigated for each ground survey. Among the 6 Vegetation Indices (VI), the RVI, NDVI, NGRDI and GLI between measured and image derived showed high relationship with the coefficient of determination respectively. Using the field investigation data, the vegetation indices regression curves were derived, and the growth parameters were tried to compare with the VIs value.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.71-82
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• 2003

The shortest path problems(SPP) are critical issues in the military logistics such as the simulation of the War-Game. However, the existing SPP has two major drawbacks, one is its accuracy of solution and the other is for only one solution with focused on just link cost in the military transportation planning models. In addition, very few previous studies have been examined for the multi-shortest path problems without considering link capacity reflecting the military characteristics. In order to overcome these drawbacks, it is necessary to apply the multi-shortest paths algorithm reflecting un-expected military incidents. This study examines the multi-shortest paths in the real networks using Shier algorithm. The network contains both military link capacity and time-based cost. Also, the modes are defined as a platoon(group) rather than unit which is used in most of previous studies in the military logistics. To verify the algorithm applied in this study. the comparative analysis was performed with various sizes and routes of network which compares with Dijkstra algorithm. The major findings of this study are as follows ; 1) Regarding the unique characteristics of the military transportation plan, Shier algorithm, which is applied to this study, is more realistic than Dijkstra algorithm. Also, the time based concept is more applicable than the distance based model in the military logistics. 2) Based on the results from the various simulations of this study the capacity-constraint sections appeared in each scenarios. As a consequence, the alternatives are necessary such as measures for vulnerable area, improvement of vehicle(mode), and reflection of separated-marching column in the military manuals. Finally. the limits and future research directions are discussed : 1) It is very hard to compare the results found in this study. which is used in the real network and the previous studies which is used in arbitrary network. 2) In order to reflect the real military situations such as heavy tanks and heavy equipment vehicles. the other constraints such as the safety load of bridges and/or the height of tunnels should be considered for the future studies.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.25-31
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• 2008

Information on daily maximum air temperature is important in predicting the status of plants and insects, but the uneven and sparse distribution of weather stations prohibits timely access to the data in regions with complex topography. Since cumulative solar irradiance plays a critical role in determining daily maximum temperature on any sloping surfaces, derivation of a quantitative relationship between cumulative solar irradiance and the resultant daily maximum temperature is a prerequisite to development of such estimation models. Air temperatures at 8 sideslope locations with similar elevation and slope angle but aspect, circumventing a cone-shaped, grass-covered parasitic volcano (c.a., 570 m diameter for the bottom circle and 90m bottom-to-top height), were measured from June to December in 2007. Daily maximum temperatures from each location were compared with the average of 8 locations (assumed to be the temperature measured at a "horizontal reference" position). The temperature deviation at all locations increased with the day of year (or sun elevation) from summer solstice to winter solstice. Averaged over the entire period, the south facing location was warmer by $1^{\circ}C$ in daily maximum temperature than "horizontal reference" and the north facing location was cooler by $0.8^{\circ}C$ than the reference, resulting in the year round average south-north temperature difference of $1.8^{\circ}C$. In November, both south and north facing slopes showed the greatest deviation of $+2.0^{\circ}C$ and $-1.3^{\circ}C$, respectively in daily maximum temperature at monthly scale. On a daily scale, the greatest deviation was +3.8 and $2.7^{\circ}C$ at the south and north slope, respectively. The cumulative solar irradiance (on the slope for 4 hours from 11:00 to 15:00 TST) explained >60% of the variance in daily maximum temperature deviations among 8 locations, suggesting a feasibility of developing an estimation model for daily maximum temperature over complex topography at landscape scales.

• Journal of Biosystems Engineering
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• v.12 no.3
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• pp.30-41
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• 1987

The geometrical shape of a plow bottom may be the most important factor affecting the performance of a plow for a given soil and operating conditions. There are various designs of the Jaenggi (Korean plow) available commercially, which may be different from each other and from the plow (Western plow) in respect to the shape and performance. This study was intended to investigate the geometrical characteristics of Jaenggi. The coordinate digitizer equipped with 3 potentiometers was designed and manufactured for measurement of the shape of curved plane of moldboard and share. The digitizer was connected to a microcomputer having the data acquisition system. This device was used to analyze the plow bottoms of 5 differently-made Jaenggis and one cylindrical plow. The results of the study are summarized as follows: 1. It was possible to measure easily and quickly the curved plane of plow bottom and to plot the view on three major plans using the coordinate digitizer electrically connected to a microcomputer system. 2. The shape of five Jaenggi bottoms analyzed could be characterized by the cutting angle having the range of $33-42^{\circ}$, the maximum share-lift angle of $41-50^{\circ}$, and the setting angle of moldboard wing of $46-70^{\circ}$. The most critical difference of the shape factors between the Jaenggi and the plow was found in the maximum share-lift angle, the former was more than twice as much as the latter. 3. The analysis of the shape of Jaenggi bottoms showed that the share projections on 3 major plans had a varied triangle, which was quite different from that of plow bottom. Especially, it was analyzed that the shape of furrow slice for the Jaenggi had a skewed rectangle, leaving a considerable height of the ridge at the furrow bottom. 4. The dihedral angle was similar range of $30-85^{\circ}$ for the all bodies investigated, but the directional angle was somewhat different from each other. The difference in directional angle was $5^{\circ}$ for the plow, $20^{\circ}$ for the Jaenggi A and $30^{\circ}$ for the Jaenggi B. 5. Area of the spherical representation region was 0.0328 for the plow, 0.1194 for the Jaenggi A and 0.1716 for the Jaenggi B. This may indicate that the plow came close to a working surface and the Jaenggi A and the Jaenggi B departed from a working surface to a somewhat greater extent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.163-172
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• 1987

Results obtained from this study conducted to find the effect of wind-break net on reducing cold wind damage in the eastern coastal cold wind damaged area are summarized as follows. The rice critical safe heading date was up to Aug. 10 in the eastern coastal area, which the frequency of gale Aug. 10 to Sep. 10 is high. The frequencies of westries and cold wind from sea were 25%, respectively, in this area. The effects of wind-break net on reducing wind verocity were 26.9, 34,6% with raising air temperature of 0.4-0.7$^{\circ}C$ and water temperature of 0.3-0.5$^{\circ}C$. The effect of wind-break net was up to 10 time's distance of wind-break net's height from wind-break net. The installation of wind-break inhanced to rice growth, so showed the heading date earlier by 2-5days and increased culm length, no.of panicles per hill and no. of spiklets per panicle. The yield decrease in this area was due to sterilization, poor ripening and light 1,000 grain weight. The yields showed 20-28% increase by installation of wind-break net. The effect of wind-break net was most in the installation plot with wind-break net against cold wind from sea and westries installed in the panicle formation stage.

• Korean Journal of Environmental Agriculture
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• v.17 no.2
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• pp.122-126
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• 1998

This experiment was conducted to verify the responses of major crop species to saline stress.To determine the saline tolerance of crop species, sevral crop species were cultivated under sand-culture system using Hoagland's nutrient solution whit 200mM NaCl. The crop species showing saline tolerance were cotton(Gossypium indicum), maize(Zea mays), barely(Hordeum vulgare), and wheat(Triticum aestivum) but perilla (Perilla frutescens) and leguminous crops, mung bean(Phaseolus radiatus), azuki bean(Phaseolus angularis) and soy bean(Glycin max) showed very por tolerance. One the typical symptom was the darkening of leaf color due to increase of chlorophyll concentration.Among of the plant families, Fabaceae was the most susceptible but crop species belonging to Poaceae were more proper for cultivating on reclaimed tidal land in the course of desalinazation. It was suggrsted that the crop species belonging to Fabaceae, a sensitive family to soil salinity, must be cultivated when the soil salinity decreased below 10ds/m. To know the critical salinity level for crop growth,salinity of saline soil collected from reclaimed tidal land was adjusted from 10.0ds/m tp41.7ds/m with tap water. It was suggested that the ECs of the soil in which the plant height of each crop spicies was reduced to 50% of control plant were 22.6 and 21.7 ds/m in rice, barley, corn, mung bean, and soy bean,respectively.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.786-796
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• 2008

This study examined the influence of the nutrient intake status, dietary habit, and academic stress of elementary school children on their academic achievement. Two-hundred and twenty-four fifth-graders in Bucheon-si, Gyeonggido were surveyed. The study included the 24 hr-recall, anthropometric measurement, assessment of stress level and academic achievement. The subjects were normal in height, weight and Rohrer index, but higher percentage of underweight was seen in girls and vice versa in boys. The overall nutrient intake and dietary habits were fairly good, but Ca and folate intake was less than 75% KDRIs and dietary habits of boys were inferior. Academic stress level of all the subjects was not high. In terms of academic performance and its relations with nutrient intake, the more the amount of nutrient intake, the higher the academic performance. Especially, it was true for the energy, protein, phosphorus, potassium, zinc, polyunsaturated fatty acids, and n-6 fatty acid intakes (p < 0.05). The overall academic performance was higher for those who eating-out less frequently. Children with higher comprehensive dietary habit scores have shown better academic performance (p < 0.05). Less stress implied to those shown higher academic achievement while those with relatively poor academic performance showed high stress level since their grade did not improve as much as they anticipated. In conclusion, the academic achievement was higher for those who have a better nutritional status, better dietary habits, and lower stress levels. Therefore, it is critical for nutritionists, parents, and teachers to improve the nutritional status and dietary habits as well as to help them manage their stress levels, which will eventually contribute to an enhanced academic performance.