• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.890-896
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• 2012

This study was conducted to evaluate soil erosion risk with a standard unit watershed in the upper Upper Nakdong River Basin according to soil characteristics and landuse using the spatial soil erosion map. The study area is $3,605.6km^2$, which consists of 2 subbasins, 35 standard unit watersheds (Andong basin 18, Imha basin 17). As a evaluation of soil erosion potential using the spatial soil erosion map, total annual soil loss and soil loss per area estimated $2,013{\times}10^3Mg\;yr^{-1}$ (Andong basin 979, Imha basin 1,034) and $6.1Mg\;ha^{-1}yr^{-1}$ (Andong basin 6.0, Imha basin 5.2), respectively. 54.2% of soil loss was originated from Arable land (Andong basin 49.0%, Imha basin 59.0%), and the area of regions, graded as higher "Moderate" for annual soil loss, was $201.7km^2$ (Andong basin 84.9, Imha basin 116.8). Average soil loss per area of unit watersheds by classification according to soil dominant parent material types ranked "Sedimentary rock group" > "Mixed group" > "Metamorphic rock group" > "Igneous rock group". In conclusion, the results of this study inform that the classification of soil parent material type would be effective for soil erosion analysis and interpretation in the Upper Nakdong River Basin.

• Journal of Korean Society of Steel Construction
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• v.24 no.5
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• pp.503-510
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• 2012

High performance, high strength steels were developed and used in steel structures recently. Since the newly developed high strength steels posses different toughness, weldability, yield strength ratio, etc. in compare with conventional structural steels, it is requred to investigate the applicability of the design strength of fillet weld specified in the existing design codes. The comparison of the design strengths of various codes from domestic and overseas shows quite a difference. Test results for fillet weld strengths were collected and statistically analysed. Each of yield strength, tensile strength of parent material and tensile strength of weld metal was selected as a main parameter for each estimation equation respectively. All the estimation equations yield almost same values for each type of steel regardless the type of main parameter selected. Considering the behaviour of fillet welded joints and for practical purposes, it is proposed that the equation with tensile strength of parent material is to be used in design codes. The comparison with the proposed nominal strengths of fillet welds shows that the existing design codes could lead to an uneconomical result for low strength steels and lie on an unsafe side for high strength steels.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.191-194
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• 1992

The tomb of the king Muryung, the 25th king of ancient Baegje dynasity in Korea, was proved to be constructed about 1500 years ago. The Physico-chemical characteristics were determined in order to investigate the pedogenic process for tomb soils. Clay and silt content inclosed down to 30~40cm soil depth. The increase of clay was 13.4% in the 10cm surface soil and the estimated time for 1% increase of clay in the profile was about 112 years. There were great changes in chemical properties in the 10cm surface soil, and considerable accumiration of salts and increase of catiom exchange capacity(CEC) down to 30cm depth. The alteration of primary minerals and formation of clay minerals were great in the 10cm surface soil and considerably reconized down to 50~60cm. The result suggested that the development of soil profile from the tomb parent material for the period was 10cm under the forest environment in Korea. The parent material of tomb soil was considered to be transported greyish green clored diorite from other place.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.490-498
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• 2010

Isotianil is a fungicide which has prevention effects against rice blast disease. In order to register this new pesticide, the series of toxicity data on animal testing were reviewed to evaluate its hazards to consumers and to determine its acceptable daily intake. Isotianil was almost excreted by urine and feces. It has low acute oral toxicity while has no skin toxicity and ocular irritation. Its skin sensitization was evaluated as slight. Genotoxicity of parent compound and metabolite was negligible. Chronic toxicity tests on rats and dogs showed changes of hematology, clinical biochemistry and liver weight. It had no reproductive and teratogenic effects. The estimation of Acceptable Daily Intake(ADI) is based on the lowest no-observed adverse effect level (NOAEL). The lowest NOAEL of 2.83 mg/kg bw/day was found in the twelve-months rats study. The NOAEL was based on increased liver weight and treatment-related effect on clinica chemistry finding at the nest higher dose level of 2.83 mg/kg bw/day. Therefore, it is considered appropriated to apply an uncertainty factor of 100 to the NOAEL 2.83 mg/kg bw/day from the rat study, resulting in an ADI of 0.028 mg/kg bw/day.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.9-15
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• 1995

This study was carried out to investigate the effects of the optimal fertilizer application levels and planting space at different seeding parts on Chinese yam from 1992 to 1993. The results obtained was as follows： The earlist day to emergence was 42~56 days at tuber section, 37~46 days at an aerial tuber, and 50~56 days at an exposed parent material. in turn. The days to emergence were delayed by increasing fertilizer application levels. In the growth of the under-ground parts, vine length was increased in a tuber section, aerial tuber, and an exposed parent material in turn. The tuber section by 60${\times}$20cm at planting space, 56-56-64 Kg/10a at fertilizer application levels was appeared to be good growth among underground parts. As planted close, the growth of tuber section was decreased. The totoal yield was appeared to be increased about 19% in a tuber section planted as 30${\times}$20cm compared with 60${\times}$20cm. In an exposed parent ma-terial, the planting space, 30${\times}$15cm, was increased 10% compared with 45${\times}$15cm, and in an aerial tuber, the planting space, 10${\times}$10cm, was increased about 10% comparing 30${\times}$10cm. Fertilization level(N-$P_2O_2K_2O$) in 56-56-64Kg/10a was increased 39 to 47% comparing 28-28-32 Kg/10a. And the heavy dressing and the close planting space were appeared to be produced the highest yield. In considering commercial quality, the optimal combination between seeding parts and planting space is recommended to improve commercial qualities and high yield.

• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.37-42
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• 1976

In this study, an effort was made to find out more effective methods for vegetation establishment on denuded forest land along Cheon Bo Mountains, This area has serious sheet erosion as a major erosion process and parent material is granite gneiss which is known as one of the most erosive materials. Lespedeza bicolor, Arundinella hirta and Robinia pseudoacacia were used as ground cover species. Seeding methods were open broadcast seeding and broadcast seeding with straw mulch, dill seeding with 10cm and 20cm width, and spot seeding with 20cm and 30cm diameter. 1. On slopes less than 30 degrees, broadcast seeding method with straw mulch was the most effective way to establish vegetation cover. 2. On steep slopes more than 30 degrees, 10cm drill seeding method was more effective than the other methods. 3. Soil Texture has an influence on vegetation establishment governing soil moisture condition. Coverage and fresh weight were increased with the fine material qantity in soil. 4. In process of year, coverage was increased with fresh weight. On the other hand, survival decreased.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.84-91
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• 2010

We built multi-purpose large triaxial testing system that can test and evaluate various geotechnical design parameters such as shear strength, deformation modulus and stress-strain behaviour for large diameter granular materials, which are the most commonly used construction materials in the railway, road embankments. The details of the built testing system and the results obtained from static triaxial test carried out for gneiss ballast material are discussed within the scope of this paper. Ballast is hardly saturated and is confined at low overburden pressure, since the depth is shallow and the permeability is very high. Herein we ascertained that the confining pressure can effectively be controlled by vacuum. The rational trend could be checked up through triaxial test results such as shear strength, deformation, and particle breakage. And the shear strength envelope could be non-linearly represented with the parent rock strength, confining pressure of the triaxial test and proper parameters.

• Journal of the Korea Society of Computer and Information
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• v.24 no.8
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• pp.151-158
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• 2019

In this paper, we conducted a study to understand the impacts of safety behavior, safety and health delivery and communication, which should be managed for the establishments' safety and health control on occupational safety and health policy satisfaction to utilize that as a material for preparing policy support and preventive measures. For this purpose, we conducted a statistic analysis with 2,970 establishments, utilizing the material, "2015 Occupational Safety and Health Company Survey". As a result, in the manufacturing industry, it turned out in the establishments with more than 300 workers, safety behavior, safety and health delivery and communication of the cooperative firm of the prime contractor were high. In addition, it turned out that safety behaviors had the biggest impact on occupational safety and health policy satisfaction in the manufacturing industry and safety and health delivery and communication had the biggest impact on occupational safety and health policy satisfaction in the construction industry and other industries. As for the relationship between companies, it turned out that safety behaviors had the biggest impact on that between the parent company and a cooperative firm of a prime contractor while safety and health delivery and communication on that between the prime contractor and the subcontractor. Through the results of this study, it is necessary to build up safety and health behavior and safety and health delivery and communication systems for the characteristics of the company, and it is expected that the effect of the safety and health control will increase when policy support is made accordingly.

• Journal of Electrochemical Science and Technology
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• v.12 no.2
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• pp.246-256
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• 2021

Mo,Cu-doped CeO₂ (CMCuO) nanopowders were synthesized by the nitrate-fuel combustion method aiming to improve the electrical and electrochemical properties of its Mo-doped CeO₂ (CMO) parent by the addition of copper. An electrical conductivity of ca. 1.22·10^-2 S cm^-1 was measured in air at 800℃ for CMCuO, which is nearly 10 times higher than that reported for CMO. This increase was associated with the inclusion of copper into the crystal lattice of ceria and the presence of Cu and Cu₂O as secondary phases in the CMCuO structure, which also could explain the increase in the charge transfer activities of the CMCuO based anode for the hydrogen and carbon monoxide electro-oxidation processes compared to the CMO based anode. A maximum power density of ca. 120 mW cm^-2 was measured using a CMCuO based anode in a solid oxide fuel cell (SOFC) with YSZ electrolyte and LSM-YSZ cathode operating at 800℃ with humidified syngas as fuel, which is comparable to the power output reported for other SOFCs with anodes containing copper. An increase in the area specific resistance of the SOFC was observed after ca. 10 hours of operation under cycling open circuit voltage and polarization conditions, which was attributed to the anode delamination caused by the reduction of the Cu₂O secondary phase contained in its microstructure. Therefore, the addition of a more electroactive phase for hydrogen oxidation is suggested to confer long-term stability to the CMCuO based anode.

• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.185-197
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• 1991

The purpose of this study is to explore family relations of the Elderly influencing adjustment of the Elderly. The Sample was selected from elderly women who are older than 65years living in Seoul. Total sample consisted of 324 elderly women(married women 155, widow 169) finally selected datum sources. Factor analysis, frequency distribution, percentile, Anova, Pearson's Correlation and Stepwise multiple regression were used to take statistics. The main resluts were as follows: 1. The score of the adjustment of urban elderly woman was normal. 2. General characteristic variables such as age, self-reported health, financial status and supply of living expenses have turned out to be significant on the adjustment of the elederly women. 3. General satisfaction of married life, among the subordinate dimensions of the aging Couple relationships, has influence of the adjustment of the elderly women. 4. Among the old parent-Adult children relationships, subjective solidarity and consensual solidarity have influence on the adjustement of the aged. Besides the above two solidarity, objective solidarity has influence on the adjustment, in the case of widow. 5. Among the grandmother-grandchildren relationships, discipliner relations and material provider relations have influence on the adjustment of the married old women. Besides the above two solidarity, surrogate parenting relation have influence on the adjustment, in the case of widow.