• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.5-16
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• 2012

In the case of using the soil materials created by cutting in-situ ground directly without adjusting particle size, it is recommendable to seek the compaction property or material constant required for filling design or density control through indoor test, and many studies on this subject have been carried out during that time. The researches conducted during that time, however, were focused on the mixed materials with different diameters that exist in a natural condition. There has been no study conducted using coal fly ash that is by-product of the thermal power plant that is actively considered as the building materials. Therefore, this study was aimed at implementing compaction test and examining the basic engineering property in order to explore the influence of crushing the particles through compacting the admixture of crushed stone and coal fly ash produced from thermal power plant on its engineering property, and then the impact of the admixture volume of each material on compaction property and material property by conducting the One-Dimensional Compression Test. As result of compaction test, the optimum moisture ratio of coal fly ash was shown to be approx. 23%. As result of compaction test in accordance with the mixed ratio of coal fly ash and crushed stone under the same compaction energy and moisture ratio, dry unit weight tended to drop when the mixed ratio of coal fly ash exceeded 30%, while it reached approx. $1.81gf/cm^3$ when the mixed ratio was 30%. As result of One-Dimensional Compression Test in accordance with the mixed ratio of crushed stone and coal fly ash, the change in void ratio by particle crushing was at the highest level in the case of coal fly ash 100%, while the lowest level in the case of crushed stone 100%. In the case of mixed materials of crushed stone and coal fly ash, compression index was at the lowest level in case of coal fly ash 30%, and therefore this ratio of mixed material was judged to be the most stable from an engineering aspect.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.67-74
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• 2012

PURPOSES: In this study the influence factors related to abrasion resistance of interlocking concrete block have been evaluated, and comparisons between various domestic and foreign abrasion test methods was also accomplished. METHODS: The modified rotational cutting method suggested in ASTM C 944 was applied. Surface materials with different types of fine aggregate such as crushed sand, sea sand, and mixture of crushed and sea sand were tested to compare the aggregate effect for abrasion resistance. RESULTS: The different surface mixtures with various W/C ratios, mortar and fly ash ratios have been investigated for functional and economical considerations. CONCLUSIONS: This study had obtained reliable results by changing diamond blade of rotating cutter. Therefore, in order to improve the abrasion resistance of interlocking concrete block for road, a new mix design was proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.427-427
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• 2007

The global applications of aspherics surfaces will expand rapidly on the electronics, optical components, communications, aerospace, defense, and medical optics devices etc. Especially, Asymmetric aspheric prism lens is one of the important parts in HMD(Head Mounted Display) because it affects dominantly on the optical performance of HMD. The mold core is the most important device to produce the plastic lenses by injection molding method. In this study, the mold cores for asymmetric aspheric prism lens were processed using fly-cutting method which is kind of the ultra precision processing and form accuracy and surface roughness of the cores were measured.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.3
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• pp.65-70
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• 2007

Generally, the core component of small precise optical device demands high accuracy of manufacturing processes. Although, the geometry of it is simple, the manufacturing technique to materialize is categorized as the ultra-precision machining and it must be done with the specialized machines and by the trained operator. Typical examples of small precise optical device are laser printer and phone camera. As a core part of laser printer, polygon mirror is used in laser scanning unit(LSU). It couldn't be fabricated with conventional machine but specified machine for polygon mirror machining. In this study, Polygon mirror with 16 surfaces was manufactured in the process of ultra-precision fly-cutting with Al material and investigated optimum machining conditions in terms of feedrate, pitch per cycle and depth of cut. Owing to process of polishing has bad influence on reflection angle, surface roughness, $R_{max}$=10nm, and form error, $Ra={\lambda}/10({\lambda}=632nm)$, are prerequisites for polygon mirror.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.749-760
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• 2007

The purpose of this study was to evaluate the microbiological quality of non-heat-processed foods and the effects of HACCP implementation. Here, cabbage salad and cucumber&onion salad were selected and we investigated HA(Hazard Analysis) by checking microbiological quality, time and temperature, pH, and water activity at each processing stage. Thus, the receiving of spices and dressings, washing and sterilizing, cutting, cooking, and serving stages were all considered CCPs. Before implementing HACCP, microbial analysis showed that standard plate counts and coliform counts were higher than standard levels in most of the raw ingredients of each menu, as well as during the production process. The microbiological quality of the utensils and employee's hands used during cooking indicated levels requiring direct management. Evaluations of falling bacteria-in the foodservice establishment work areas ranged from $2{\sim}12CFU/plate$. However, after HACCP implementation, microbiological levels improved to standard levels fly sanitation education. Also, the number of falling bacteria were lower than before implementing HACCP. Therefore, it is essential the foodservice operations make efforts to implement HACCP, so that microbiological hazard levels are lowered and hygienic status improved.

• Fashion & Textile Research Journal
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• v.9 no.3
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• pp.270-277
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• 2007

Buddhist temples and halls signify paradise on earth. Buddhist sutras refer to paradise as a place where flowers fall down like snow, fragrance and music fill the air, flowers blossom and butterflies fly. The Kkot Mun of Buddhist temples are an essential part of the creation of this paradise and are ornamented with elaborate sculptures of flowers and animals. The ornamentation of the Kkot Mun is truly admirable for its artistry and beauty. Although the Kkot Mun is an element of Korean traditional Buddhist architecture, it could also be applied to costume work. I thought the characteristic elements of the Kkot Mun for the costume work were the flower, the lattice and the transparent effect that was made with the lattice and Dagjongee. I used the technique of strap cutting, strap twisting and cut-out for the lattice of Kkot Mun and flower making, knitting, cut-out and quilting for the flower of Kkot Mun. I represented the transparent effect of Kkot Mun with the lapped materials. I selected six remarkable Kkot Mun of Korean temples, revised shapes of these and made six costume works. These six costume works would be the suggestion of costume design if an element of Korean traditional architecture was applied to modern costume making.