• Magazine of the Korean Society of Agricultural Engineers
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• v.26 no.4
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• pp.52-65
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• 1984

In general precise estimation of hourly of daily distribution of the long-term run-off should be very important in a design of source of irrigation. However, there have not been a satisfying method for forecasting of stationar'y long-term run-off in Korea. Solving this problem, this study introduces unit-hydrograph method frequently used in short-term run-off analysis into the long-term run-off analysis, of which model basin was selected to be Sumgin-river catchment area. In the estimation of effective rainfall, conventional method neglects the Soil moisture condition of catchment area, but in this study, the initial discharge (qb) occurred just before rising phase of the hydrograph was selected as the index of a basin soil moisture condition and then introduced as 3rd variable in the analysis of the reationship between cumulative rainfall and cumulative loss of rainfall, which built a new type of separation method of effective rainfall. In next step, in order to normalize significant potential error included in hydrological data, especially in vast catchment area, Snyder's correlation method was applied. A key to solution in this study is multiple correlation method or multiple regressional analysis, which is primarily based on the method of least squres and which is solved by the form of systems of linear equations. And for verification of the change of characteristics of unit hydrograph according to the variation of a various kind of hydrological charateristics (for example, precipitation, tree cover, soil condition, etc),seasonal unit hydrograph models of dry season(autumn, winter), semi-dry season (spring), rainy season (summer) were made respectively. The results obtained in this study were summarized as follows; 1.During the test period of 1966-1971, effective rainfall was estimated for the total 114 run-off hydrograph. From this estimation results, relative error of estimation to the ovservation value was 6%, -which is mush smaller than 12% of the error of conventional method. 2.During the test period, daily distribution of long-term run-off discharge was estimated by the unit hydrograph model. From this estimation results, relative error of estimation by the application of standard unit hydrograph model was 12%. When estimating by each seasonal unit bydrograph model, the relative error was 14% during dry season 10% during semi-dry season and 7% during rainy season, which is much smaller than 37% of conventional method. Summing up the analysis results obtained above, it is convinced that qb-index method of this study for the estimation of effective rainfall be preciser than any other method developed before. Because even recently no method has been developed for the estimation of daily distribution of long-term run-off dicharge, therefore estimation value by unit hydrograph model was only compared with that due to kaziyama method which estimates monthly run-off discharge. However this method due to this study turns out to have high accuracy. If specially mentioned from the results of this study, there is no need to use each seasonal unit hydrograph model separately except the case of semi-dry season. The author hopes to analyze the latter case in future sudies.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.20-26
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• 2013

This study was conducted to improve the managing and storing methods of the seeds of Aralia cordata var. continentalis (Kitagawa) Y.C.Chu, to examine the viability and the germination ability of seeds with different storing conditions and methods, and to develop new ways to propagate and have better healthy seedling. Therefore, the germination rate, days required for germinating seeds, and early growth responses of Aralia cordata var. continentalis (Kitagawa) Y.C.Chu were investigated with different storing temperatures, durations and methods. The germination rate was higher in stratified storage than that in dry storage condition. The highest germination rate was with outdoor temperature at 30 days after stratified storage. The days required for germinating seeds were less than 10 days with the treatment of $25^{\circ}C$ and outdoor temperature in stratified storage. In dry condition, they were shorter with $4^{\circ}C$ and $25^{\circ}C$ than those with $-20^{\circ}C$ and outdoor temperature. Leaf number of seedling was higher in stratified storage compared to that in dry condition, while it was not clearly different according to storage temperatures and durations. Leaf length and leaf width of seedling was not difference among the treatment of storage methods, temperatures, and durations. Stem length of seedling was higher in stratified storage than those in dry condition, while root length was not clearly different among the treatments. It would be assumed that temperatures, methods and durations of storage could affect much to the germination rate and the early seedling growth response.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.263-268
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• 2007

This experiment was carried out to evaluate the effects of organic content and to select lodging resistance for six varieties in paddy field of Chungnam province from 2006 to 2007. In this experiment, plant height was increased at the high fertile field and dry matter rate (%) per fresh matter was decreased at the high fertile soil condition but dry matter rate (%) of spike was increased. The dry matter (DM) yield showed higher in Sunwoo barley (13,520kg/ha) and Youngyang barley (12,780kg/ha) at the high fertile field. Fresh yield was also high in Wooho barely (34,720kg/ha) and Youngyang barely (33,670kg/ha) at the high fertile field but yield in high and normal fertile soil condition was not difference. Total digestible nutrients (TDN) content of Youngyang barley and Yuyeon barley was high as 69.5%, 70.3%, respectively, at the high fertile soil condition. According to this result Soman barley and Youngyang barley might be recommendable for whole crop barely in lower organic content condition of paddy rice field and Wooho barley and Soman barley with the lodging resistance and high yield is suitable for paddy field with high organic content.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.119-126
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• 2011

This experiment was carried out to know adaptability and forage production and quality of sorghum, sorghum ${\times}$ sudangrass and sudangrass hybrids depend on drained condition at paddy field from 2007 to 2008 at Chungnam province. Growth, forage production and quality of sorghum, sorghum ${\times}$ sudangrass and sudangrass hybrids showed more well drained condition than poorly drained condition at paddy field. Among growth characteristics, 'SS405' hybrids were somewhat strong for waterlogging, then and good at stem diameter, disease resistance. The dry yield of 'SS405' hybrid at poorly drained paddy field was the highest as 12,938 kg per ha. Fresh yield of poorly drained paddy field was 52.7% compared to that of well drained paddy field. The dry matter yield of poorly drained paddy field was the lower as 66.4% than that of well drained condition. ADF (acid detergent fiber), NDF (neutral detergent fiber), CP (crude protein) and IVDMD (in vitro dry matter digestibility) in poorly drained paddy field were 90.3%, 100.6%, 85.7% and 89.6% level compared to well drained paddy field.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.144-155
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• 1994

Scanning electron micrography and Transmission electron micrography studies were performed on the surfaces of stem(coleoptiles) of rice and barnyardgrass under various cropping patterns at 5 days after seeding or transplanting. Stem surfaces of rice under dry condition possessed rodlet-like epicuticular waxes, trichomes, stomata and cork cell layer in both broadcast and drilled rice while barnyardgrass had only thread-like epicuticular waxes, but trichomes, stomata and cork cell layers were not found. However, rice under water condition has no rodlet-like waxes, stomata and cork cells, and barnyardgrass was similar to that under dry condition. On the other hand, those on stems of 8-day and 25-day transplanted rice were well arranged and developed compared with those of direct seeded rice. Electron micrography showed significant difference in thickness of outer epidermal cell walls of rice and barnyardgrass under dry, water and transplanting condition. Thickness of outer epidermal cell was greater in transplanted rice, dry direct seeded rice, water-direct seeded rice and barnyardgrass in descending order.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.98-102
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• 2001

We investigated the changes of chemical compositions during fermentation of salted anchovy by salting methods for the purpose of establishment of processing condition. Dehydration of anchovy meat occurred remarkably by dry salting compared with that by brine salting and salinity was higher in anchovy by brine salting than by dry salting. Dehydration and salinity were increased in more anchovy fermented at $20^{\circ}C$ than at $5^{\circ}C$. Total nitrogen content was lower in anchovy by brine salting than by dry salting. Amino nitrogen increased remarkably during fermentation of salted anchovy at $20^{\circ}C$, while increased slightly at$5^{\circ}C$. Amino nitrogen showed maximum value on 120 days in dry salting and on 30 days in brine salting at $20^{\circ}C$, respectively. The changes of VBN were similar to the changes of amino nitrogen. The brine salting accelerated hydrolysis of anchovy meat compared with that of dry salting at $20^{\circ}C$, and the hydrolysis were suppressed at $5^{\circ}C$, The POV increased rapidly in dry-salted anchovy than brine-salted anchovy. We suggested that the appropriate processing condition of salted anchovy is to ferment for 5-6 months at $5^{\circ}C$ by addition of $25\%$ salt after pre-salting of raw anchovy.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04a
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• pp.93-98
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• 1996

Friction and wear characteristics of metals in dry and boundary lubricated sliding conditions are observed experimentally using pin-on-disk and pin-on-plate type tribotesters. The motivation of this research is to investigate the effect of sliding history on the tribological behavior of metals. Cu and SM45C steel materials were used for the experiment. The results show that in dry condition the fictional behavior as well as wear of the specimens differed between uni-directional and bi-directional sliding conditions. The friction coefficient values, wear profile and optical micrograph of the wear track are presented.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.417-418
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• 2002

The dry sliding tribological characteristics were investigated using SiC particle-reinforced aluminum composites against semi-metallic frictional materials. The experimental results have indicated that, whether under the condition of continuous braking or not, the wear rates of SiC particle reinforced composites are much less than that of gray cast iron which is used as one of the common brake disk materials. At the same time, their frictional coefficients are about the same.

• Transactions on Electrical and Electronic Materials
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• v.7 no.5
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• pp.262-266
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• 2006

The insulation diagnostic test and the AC breakdown test were performed under off-line using the 3.3 kV class induction motor which have been served for 10 years. These tests were conducted in means of nondestructive and destructive test. In this paper, we compared the correlation between the nondestructive and destructive test. Furthermore we setup an experimental condition with moisture and compared the insulation characteristics between moist and dry sample. From the results of the nondestructive and destructive test, it was found that the second AC current, which is the previous step of insulation breakdown, suddenly increased at a point of around 8.5 kV. The insulation breakdown of moist sample occurred at 12-14 kV, which is 4-5 kV lower than dry sample.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.05a
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• pp.197-202
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• 2005

This study started to confirm and prove for the applicability of the dry-process waterproofing system to cover the defects of the wet-process waterproofing system according to weather circumstance, foundation condition and maintenance, etc. This process has triple combined waterproofing system using asphalt sheet, metal sheet, engineering plastic film. It is not influenced by the concrete's crack as the foundation of the roof according to the movement of the building because the waterproofing system is designed for maintaining good quality by absorbing the stress of contraction and expansion that is occurred by the variation of temperature. Ali components used in this process can be recycled environmentally. The superiority of this process proved and reconfirmed through with the investigation of about 130 fields, around 30,000nf for two years.