• Proceedings of the KIEE Conference
• /
• 1999.07a
• /
• pp.489-491
• /
• 1999

본 연구에서는 경부고속철도 수익관리시스템 구축방안 연구의 일환으로 철도에 수익관리기법을 도입의 타당성과 그 효과를 검토하기 위하여 현재의 철도에서 사용되고 있는 예약체계, 운임체계 및 좌석할당 방법을 분석하였다. 지금까지 널리 사용되고 있는 여러 가지 수익관리기법을 적용하기 위한 조건을 제시하였으며, 예약실적자료를 사용하여 그 효과를 계산하였다.

• Proceedings of the KIEE Conference
• /
• 1999.07a
• /
• pp.86-88
• /
• 1999

An analysis of temperature distribution in transformer is necessary for cooling design. But, it is very difficult to make that analysis because of the complicated structure of transformer. Particulary. if it is asymmetry, 3 dimensional analysis is required. This paper presents the 3-dimensional analysis technique of temperature distribution in transformer using a commercial CFD program FLUENT and the applied results in a simple model.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.61-64
• /
• 2001

Demand for development of 154kV Less-Flammable Power transformer is now increasing greatly instead of a oil-immersed transformer for preventing disasters and Less-flammability of substations. The most important point in developing Less-flammable transformer is cooling system. This paper describes the study on cooling characteristic of Less-flammable transformer.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.687-688
• /
• 2011

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2012.07a
• /
• pp.30-33
• /
• 2012

• Applied Biological Chemistry
• /
• v.48 no.2
• /
• pp.166-172
• /
• 2005

In order to prepare liqueur of Acanthopanax koreanum, changes in major constituents by soaking below 0.5 cm size dried sample 700 g in 10 l of $15{\sim}95%$ spirit solution for 70 days were investigated. Color b was increased according to lower ethanol concentration and longer soaking periods. Extract was increased gradually with soaking periods, and the content was $0.6{\sim}0.7%$ (w/v) with stem, $1.0{\sim}1.5%$ (w/v) with root. Eleutheroside B and E were extracted rapidly within 20 days of soaking, moreover were increased according to ethanol concentration within 15% to 70%. Acantoic acid was extracted rapidly $2.8{\sim}22.6\;{\mu}g/ml$ with stem, and $560{\sim}1,700\;{\mu}g/ml$ with root within 5 to 10 days. For preparation of liqueur of Acanthopanax koreanum, it is necessary to soak more portion of dried root with $60{\sim}80%$ ethanol concentration for $30{\sim}50$ days, and then to blend after aging for 13 weeks.

• Journal of the Korean Chemical Society
• /
• v.38 no.7
• /
• pp.485-495
• /
• 1994

Several new symmetric and asymmetric homo and hetero dinuclear complexes of the type $[Cl(dppp)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$ and $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$(M,M'= Mo or W; phen = 1,10-phenanthroline; dppp = 1,3-bis(diphenylphosphino)propane; pyz = 1,4-pyrazine) were synthesized in three-steps starting from $[M(NO)_2Cl_2]_n(M = Mo, W)$. The final products were purified by eluting it through silica gel column ($2{\times}20$ cm) with acetone as the eluent. Characterization of these complexes and some related complexes was accomplished through UV-vis., $^1H$-NMR, $^{13}C$-NMR and IR spectroscopies as well as elemental analysis. The infrared spectra indicate that the NO groups occupy cis-positions of the octahedral. The $^1H$ and $^{13}C-NMR$ data for the new compounds revealed a dimeric structures with bridged pyz.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.304-307
• /
• 2008

In order to evaluate the effect of permanent softening behavior on springback prediction, 2D-draw bending simulations were compared with experiments for friction stir welded DP590 steel sheets. To account fur the nonlinear hardening behavior, the combined isotropic-kinematic hardening law was utilized with and without considering the permanent softening behavior during reverse loading. Also, the non-quadratic orthotropic yield function, Yld2000-2d, was used to describe the anisotropic initial-yielding behavior of the base sheet while anisotropic properties of the weld zone were ignored for simplicity.

• Electronics and Telecommunications Trends
• /
• v.26 no.5
• /
• pp.14-28
• /
• 2011

모바일 혁명과 빅데이터(big data) 시대에 접어들면서 사용자 중심의 자연스러운 인터페이스와 정보검색에 대한 요구가 늘어가고 있다. 모바일 환경에서의 쉽고 자연스러운 검색을 위해 음성인식 기술을 이용한 음성검색 서비스가 대세를 이루고 있으며 대화형 검색 서비스로 발전하게 될 것이다. 음성 대화 서비스의 주요 응용 분야인 음성검색 및 외국어 교육 서비스에서의 자연어 음성인식 기술 역할 및 사용자 경험을 바탕으로 하는 선순환 구조의 인식 성능 개선에 대해 소개한다. 또한 두 응용분야에서의 국내외 개발동향을 소개하고 실제 개발 사례를 통해 무제한급 자연어 음성인식 기술에 기반한 음성 대화 서비스의 가능성을 살펴본다.

• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.962-967
• /
• 2003

Recently, environmental pollution has become a serious problem in industry, and many researches have been done in order to preserve the environment. The coolant, which promotes lubrication, cooling and penetration, contains chlorine, sulfur and phosphorus to improve the machining efficiency. These additives, which move around into the air during machining, pollute working. Therefore, many researches on how to reduce the amount of coolant during machining have been carried out. However, to reduce even small amount of coolant causes high temperature of a workpiece and it brings thermal defects. In this study, the experiments of wet & dry grinding using cooling methods (using coolant only, mist and compressed cold air only) are performed to solve the problem of environmental contamination and to get a better surface integrity of a workpiece by comparing surface roughness, roundness and residual stress.