• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.265-272
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• 2023

Lignocellulosic biomass is essential to pretreatment because of having rigid structures and a lot of lignin. Among methods of pretreatment, using THF solvents has the advantage of being easy to reuse. THF (Tetrahydrofuran) used as a co-solvent with water or ionic solvent that is inexpensive and can remove lignin over a wide range of reaction conditions. NaOH (Sodium hydroxide) has been demonstrated to preferentially solvate lignin from cellulose. Thus, NaOH was used as a pretreatment co-solvent for the fractionation of lignin by destroying the ether bond to amend for hydrolysis and expand the surface area of cellulose and hemicellulose. In this experiment, lignin was removed by the NaOH/THF co-solvent pretreatment process to characteristics for the pretreatment and obtain the optimal levulinic acid conversion yield through the acid catalyst conversion process. the NaOH/THF co-solvent system was conducted in various ratios of co-solvent under a total of 16 conditions. And the temperature was 180 ℃ during to 60 mins. The optimum condition of co-solvent is NaOH 5 wt%/THF 90:10(v/v%), 76.8% glucan content was obtained through this co-solvent pretreatment, and 90.1% lignin was removed. In the acid catalyst conversion process, which is a subsequent pretreatment process, the experiment was conducted under the conditions of 30 to 90 min of reaction time and 160 ℃ to 200 ℃ reaction temperature. The optimum condition of acid catalyst conversion process is 60min reaction time under of 180 ℃, and it obtained 84.7% of levulinic aicd conversion yield.

• Journal of the Society of Disaster Information
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• v.7 no.1
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• pp.32-42
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• 2011

Many researches have been conducted to evaluate the performance of modified asphalt concrete mixtures. The research was conducted to estimate the laboratory mechanical characteristics of Elvaloy-modified asphalt concrete mixture. To achieve its intended objective, indirect tensile test and resilient modulus test were performed. The rest results revealed that indirect tensile strengths and resilient moduli of the Elvaloy-modified asphalt concrete mixture were higher than those of the conventional dense-graded. As a result, within the limits of the tests conducted in this research, it is predicted that the performance and stability of the Elvaloy-modified asphalt concrete mixture are better than that of the conventional dense-graded one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.557-566
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• 2018

Shopping malls have been developed to increase sales revenue and attract visitors. This study focused on the sense of the outdoor characteristics of these shopping malls by comparing open and enclosed types of shopping malls in common spaces in LA and Korea through case study analyses. This research through case studies will form the foundation of comfortable shopping mall space design. The results are the follows. 1. Enclosed shopping malls tend to provide large indoor space to create a sense of outdoors. 2. The common space of enclosed shopping malls is developed through space expansion with horizontal and vertical connections that appear in different combinations depending on the space constraints and contexts. 3. The architectural planning of enclosed shopping malls are largely dependent on the concept of everyday life portrayed in the identity of each space, which usually involve the inclusion of sizable atriums to host indoor sports or special performances.

• International Journal of Highway Engineering
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• v.8 no.3 s.29
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• pp.89-103
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• 2006

This study develops the tire/pavement noise measuring trailer that can minimize the effect of various environmental noise and evaluate road noise characteristics without regard to time and spots. As literature reviews, it is examined into road noise characteristics and case studies of various CPX Trailer, and made a development plan of device. Based on these, HEART CPX Trailer is developed and conduct experiments for verification of the semi-anechoic chamber suitability, precision and field application of device. In the result of the experiment for verification of semi-anechoic chamber suitability, we can make sure that it is suitable and reliable among frequency bands. In the test of repetition measurement, we can verify excellent measurement accuracy among speeds and microphone's locations. In case of field tests using HEART CPX Trailer, it is founded that the result is similar to CPB test result carried out by Chung-Ang university in 2003. It can be concluded caused that the effect of environmental noise in and around the road including mechanical noise of a tow car was excluded. This paper confirmed and suggested that HEART CPX Trailer is suitable for evaluation of real road noise characteristics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.266-266
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• 2004

광통신 커넥터 핵심 부품인 페룰(Ferrule)은 광통신의 주요한 커넥터 부품으로 사용되며 슬리브내에서 페룰을 서로 맞대어 광섬유론 정렬하는데 사용이 된다. 광섬유의 맞대기가 정확하고 광학 특성에 영향을 주지 않도록 하기 위해서는 페룰의 외경과 표면의 초정밀 가공이 주요한 품질 특성이 된다. 페룰은 고경도 난삭재의 소구경 세라믹 재질이며 이의 가공을 위해서는 다이아몬드 연삭숫돌을 이용한 무심연삭(centerless grinding) 장치를 사용한다.(중략)

• Proceedings of the Korean Institute of Interior Design Conference
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• 2003.05a
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• pp.54-58
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• 2003

The purpose of this study is to clarify the daily living activities of the elderly with dementia and user oriented spatial needs of the staff in the common space of nursing home in Japan. Data was taken from six units of the 2 skilled facilities. The results revealed as follows; 4 types of elderly activities were founded, and physical environmental characteristics affected residents' space usage. And it was perceived like as living oriented space, social interaction space, facility space, staff oriented space. Conclusively it was suggested to plan dining space as semi-private space, day corner as semi-public space.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.49-54
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• 2004

Recently residential-commercial buildings are being built more like residential-oriented apartments and also as deluxe residential houses targeting at the high-income bracket that is seeking for high Qualify of life. The important factors to provide a pleasant environment for residential-commercial buildings are both common space shared by occupants and the quality of service and the conveniences. These have already become prominent as important factors when choosing a residence. This research manipulates the characteristics of commonly shared space, being an important factor of amenity, in the residential-commercial buildings recently built for sale so that a reference to planning of common space in residential-commercial buildings can be provided for the future.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2008.11a
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• pp.132-133
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• 2008

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.95-96
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• 2010

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2010.05a
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• pp.101-102
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• 2010