• Journal of the Korean Geotechnical Society
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• v.33 no.1
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• pp.57-65
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• 2017

During a construction of embankment, sub base, or retaining wall backfill, the speedy measurement of water content is necessary. In this study, a test method for field determination of water content of soil by the calcium carbide gas pressure (speedy water content measurement method) was evaluated for its reliability and accuracy. Dry oven and microwave oven methods were also used for water content measurement. In the test, weathered granite and Nakdong River sand in the site and kaolinite were used for water content measurement. The mass of 20, 22, 24, 26, 28, and 30 g of soil was respectively tested for 1, 3, and 5 min. The effect of each sample on water content was compared one another and analyzed. As the mass and testing time increased, the water content increased. The amount of soil was more important factor than testing time for the speedy water content measurement. In order to obtain similar result to that of dry oven method, 3 min of testing time with 24 g of soil was necessary for weathered granite classified as SM and 3 min with 30 g for Nakdong River sand classified as SP. For Nakdong River sand with 20-50% of kaolinite, the water content by speedy measurement increased as the clay content increased.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.123-128
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• 2002

Over the range(OTR) has been applied for cooking and ventilation functions especially in northern Amarica. Because flow rate and operating rpm of the double sided sirocco fan for ventilation are much higher and than the microwave oven system, the major noise source is the sirocco fm. Recently, the quiet fan development is one of very important issues for amenity. In this study, the noise source identification using multi-microphone array system was carefully carried out and numerical simulations for understanding the aerodynamic and aeroacoustic of the fan were peformed. The sound level of tonal noise is predicted with a good accuracy but that of the broadband shows some discrepancy. In order to reduce the broadband noise, the inlet region of sirocco fan have to be modified that the secondary flow should be suppressed. Based on these results, new low noise fan and OTR is now developing.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.384-389
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• 1997

Attempts were made to improve gelatinization, saccharification and panfrying processes for mass production of Nochi, a kind of traditional Korean rice cake. Gelatinization of waxy rice powder with 20-55% of moisture content were completed within a minute at 120$^{\circ}C$ or above by using the extrusion cooker. Among enzymes tested for liquefaction and saccharification of the gelatinized rice, in place of malt, BAN (0.53%)+${\beta}$-amlyase (4.27%) was the most suitable enzymes for the production of Nochi. Panfrying process of Nochi was drastically shortened by heating Nochi dough for 1 minute in a microwave oven and subsequently panfrying at 150$^{\circ}C$ for 7 minutes.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.410-416
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• 1997

Changes in sensory and physical characteristics of Wanjajeon (Korean pan fried meat balls) were investigated during chill storage for a hospital cook/chill foodservice system. Wanjajeon was cooked, stored at 2$^{\circ}C$ or 7$^{\circ}C$ for 4 weeks, and reheated by using a microwave oven. The physical characteristics such as texture, color and organoleptic properties were measured. The chewiness of Wanjajeon increased during 4 weeks of storage at both temperatures. Reheating of stored Wanjajeon resulted in a significant increase in the hardness and chewiness. The redness (a value) was significantly increased, while the lightness and yellowness (L and b values) were changed slightly. Sensory evaluation showed that Wanjajeon was acceptable for up to 3 weeks of storage at 2$^{\circ}C$ and to 2 weeks at 7$^{\circ}C$. The sample stored at 2$^{\circ}C$ was more acceptable than that of 7$^{\circ}C$ storage through the whole period.

• Journal of Korean Society for Quality Management
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• v.31 no.4
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• pp.226-238
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• 2003

Recently, The problems with which our country's company is confronted for business of manufacturing goods. This study set the hypothesis to develop the method that was analysis and application of A reliability evaluation method of environmental material for circuit components in Computer, Color TV, Monitor, Microwave oven, Electric Refrigerator, Automobile parts, other goods. Especially, this study emphasis on regulate export of the EU and North America that it's a environmental material's hazards problem. In this process, this study set the pattern of practical application. Therefore, this study emphasis on the application of A reliability evaluation method of environmental material and the use of other parameters by environmental reliability test data. The result of this study is as follows. 1) There is relationship between regulate material and technical protecting system. 2) Characteristics of hazard materials is operating a healthcare damage factor as well as regulate environmental factors.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.362-369
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• 2007

This study set the hypothesis to develop the method that was analysis and application of a reliability evaluation method of environmental material for the Computer, Color TV, Monitor, Microwave oven, Electric Refrigerator, Automobile parts, other goods. RoHS management and product reliability ensure method for the conservation of environment. Especially, this study emphasis on regulate export of the EU and North America that it's a environmental material problem. Therefore, this study emphasis on the application of a reliability ensure method of environmental material and the use of other parameter by environmental reliability test data. The result of this study is as follows. 1) There is relationship between regulate material and technical protecting system. 2) Characteristics of hazard material is operating a healthcare damage factor as well as regulate environmental factors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.223-226
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• 2004

It is net easy to predict the shrinkage rate of a plastic injection mold in its design process. The shrinkage rate should be considered as one of the important performances to produce the reliable products. The shrinkage rate can be determined by suing the CAE tools in the design produces. However, since the analysis can take minutes to hours, the high computational costs of performing the analysis limit their use in design optimization. In this study, the surrogate models based on the RSM is used in lien of the original models, facilitating design optimization.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.121-128
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• 2001

This study has been performed to investigate formability of non-vinyl PCM(pre-coated metal)sheet. First, physical test of PCM sheets were tested to evaluate finish coating characteristic of PCM. And then, test equipment was made for friction test and three non-vinyl PCM sheets were tested by straight pulling method. This paper provides the results of the friction tests showing the influence of sheet surface texture and process conditions. It was found that the influence of contact pressure and speed had an effect upon the level of friction. Also using tests, the scratch resistance of a series of polyester coating has been investigated. This investigation aims to clarify the process conditions that prevent the scratch of PCM to form the good electrical appliances such as microwave oven, air conditioner and refrigerator etc.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.99-99
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• 1993

혈액 및 생체시료 중 필수원소 혹은 독극성 원소의 극미량상분 정밀측정과 동위원소비율측정에 널리 사용되는 유도결합플라즈마 질량분석기(ICP-MS)의 기본원리를 소개하고 ICP-SM를 이용한 혈액중 낮은 ppb수준의 Cd, Hg 그리고 Pb의 정밀분석법을 소개한다. 혈액은 많은 양의 유기물을 포함하고 있으므로 digestion bomb에 질산과 과산화수소를 넣어 microwave oven에서 고온고압 상태로 분해시켜 많은 용액을 얻어 이 용액을 플라즈마에 주입시켜 분석한다. 그리고 수온은 tin(II) chloride 용액을 환원제로하여 생성시킨 수은원소증기를 membrane liquid-gas separator를 이용하여 뽑아내어 플라즈마에 주입시켜 낮은 ppt 수준의 검출한계를 얻는다. 또한 높은 정밀도와 정확도와 극미량 원소 측정에 사용되는 동위원소 회석법율 소개하고 실제 혈액분석에의 응용방법을 제시한다.

• Korean journal of food and cookery science
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• v.18 no.3
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• pp.365-371
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• 2002

This study was performed to find the changes in volatile sulfur compounds of garlic under various cooking conditions. The volatile sulfur compounds of garlic were identified with GC and GC/MS. The results of the study were summarized as follows : Chopped garlic boiled for 30min and 60min had more volatile sulfur compounds than that of fresh garlic, while 2-vinyl-4H-1,3-dithiin decreased by boiling. Whole garlic boiled for 30min and 60min had less volatile sulfur compounds than that of fresh garlic, while allyl methyl trisulfide diallyl trisulfide increased by boiling. Analyzing the change of volatile sulfur compounds under cooking methods, the order that showed more volatile sulfur compounds was as follows : grilling ＞ frying ＞ steaming ＞ boiling > microwave oven cooking > pressure cooking.