• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.1
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• pp.1-7
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• 1988

Prediction performances by Einstein's equation of diffusivity, Peskin's model, Three-Equation model, Four-Equation model and Algebraic Stress Model, have been compared by analyzing twophase (air-solid) turbulent jet flow. Turbulent kinetic energy equation of dispersed phase was solved to investigate effects of turbulent kinetic energy on turbulent diffusivity. Turbulent kinetic energy dissipation rate of particles has been considered by solving turbulent kinetic energy dissipation rate equation of dispersed phase and applying it to turbulent diffusivity of dispersed phase. Results show that turbulent diffusivity of dispersed phase can be expressed by turbulent kinetic energy ratio between phases and prediction of turbulent kinetic energy was improved by considering turbulent kinetic energy dissipation rate of dispersed phase for modelling turbulent diffusivity. This investigation also show that Algebraic Stress Model is the most promising method in analyzing gas-solid two phases turbulent flow.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.188-193
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• 1998

This paper describes static and dynamic weak point analysis of spindle systems to eliminate high concentrated bending point on spindle and improve total stiffness of spindle systems. The weak point analysis is based on the evaluation of bending curves of spindles. For static weak point analysis the bending curve is derived from static deflection curve and for dynamic weak point analysis it is derived from the mode shape curves in consideration of the transfer function at exciting point. The validity of the weak point search methodology is verified by comparison of the static deflection, the natural frequency and the dynamic compliance between the original and the improved spindle.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.15-20
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• 2001

This paper presents the experimental study of the static stiffness for the BT shank(7/24 long taper) and the HSK tool shank(1/10 short taper) in the main spindle taper of machine tool. The static stif71ess test was performed under different experimental conditions. It is turned out that the effective axial drawing force is larger than 6kN in the 7/24 test tool shank and BkN in the 1/10 test tool shank. As a test result, considering that the actual drawing force of the machining center is about 1300k2f and axal drawing force 12kN is equivalent amount as a 1220kgf, it is turned out that 1/10 test tool shank superior to 7/24 test tool shank in the static stiffness.

• 정보화사회
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• s.125
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• pp.50-57
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• 1998

미국 상무부에서 ‘98. 4월 발표한 "부상하는 디지털경제"(The Emerging Digiral Economy)는 정보기술을 기반으로 하는 디지털경제가 향후 미국 경제의 주축이 되어 미국을 이끌어 갈 것으로 예측하고 있다.

• The Science & Technology
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• v.32 no.8 s.363
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• pp.30-31
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• 1999

지난 91년 한국과학재단의 지원으로 서울대 수원캠퍼스에서 창립된 농업 생물신소재연구센터는 10개 대학 25명의 교수를 주축으로 활발한 연구활동을 계속하고 있다. 이 연구센터는 탄수화물 신소재연구부, 무공해 생물농약연구부, 천연풍미료 및 색소연구부 등 3개 기초연구부서를 두고 있는데 그동안 대표적인 연구로는 충치에 해롭지 않고 당뇨병에도 유해하지 않은 분자 올리고당을 개발했다.

• Journal of the Korean association of regional geographers
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• v.17 no.2
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• pp.150-166
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• 2011

This study aims to investigate the differences of synoptic characteristics and frontal structures over East Asia according to the main path types of water vapor flux (WVF) of 850hPa surface in cases of the heavy rainfall in the south coastal region of Korea during the Changma season (June and July), In the cases of type A in which the main path of WVF is running from the South china Sea via the South china to the South Sea of Korea, the North Pacific subtropical anticyclone (NPSA) expands to the South China and strong cyclones appear in the Yellow Sea. In cases of type B and C in those the main paths of WVF are running from the South China Sea via the Western Pacific Ocean near Taiwan to the South Sea and from the Western North Pacific Ocean to the South Sea respectively, tropical cyclones appear frequently near Taiwan and the NPSA shifts northward. In the case of type D in which the main path of WVF appear only near the South Sea, strong cyclones appear near the Yellow Sea. In all cases upper jets are intensified in the northern part of the heavy rainfall region and low-level jets appear near the main paths of WVF. In the view of frontal structure, deep active-type of the Changma front is identified in most cases of all types. In this point the Changma season is different from the Baiu season in Western Japan where many cases of shallow active-type of the Baiu front appear.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.405-406
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.597-598
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.293-294
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• 2012

• 산업보건소식
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• no.8
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• pp.18-19
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• 1984

당 협회는 10 개 지부와 5 개 산업보건센터를 주축으로 하여 산업보건사업을 추진하고 있다. 지부는 그 지역내의 노동부 지방사무소, 사입장, 관련 대학 및 특수검진기관과 협력하여, 보건관계자 직무교육, 근로자 건강진단, 작업환경측정 등의 업무를 수행하고 있다. 이달부터 지역산업보건의 중추인 각 지부를 순방하여 그 활동상을 소개하기로 한다.