• Korean Architects
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• no.2 s.120
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• pp.79-100
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• 1979

• The Science & Technology
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• v.32 no.10 s.365
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• pp.68-70
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• 1999

독일 쾰른 출신의 예수회 선교사 아담 샬은 17세기 중ㆍ후반 중국에 서양천문학을 전해준 대표적 과학자이다. 1613년 로마신학교에 들어가 성직자로서의 교육을 받았고 1617년 신부가 되어 중국으로 파견되었다. 중국 이름이 탕약망인 이담 샬은 서양의 천문학 시헌력을 중국에 소개, 일식을 정확하게 예보하는 등 명성을 떨쳤다. 특히 그는 당시 중국에 억류되어 있던 조선조 인조의 세자인 소현세자와도 만나 서양의 과학기술괄련 물건들을 전하기도 했다.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.469-473
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• 1987

This paper presents a method to estimate p.d.f.(probability density function) of harmonic phasor voltage. Because the quantity of harmonics is not fixed, stochastic analysis of harmonics is needed. Because it is impossible to obtain p.d.f. of voltage from p.d.f. of current directly, the moments of voltage and current are used. Firstly, the moments of current is calculated from p.d.f. of current. Secondly, the moments of voltage are calculated from the moments of current using the linearity of the moments. Finally, p.d.f. of voltage is estimated from the moments of voltage using Gram-Charlier Type A Series. [1] The moments of the p.d.f. obtained by the series and of the true p.d.f. is same up to given finite moments. Because current and voltage of harmonics are represented as not instantaneous values but phasors, the estimated value can be compared with the measured value and harmonic phasor voltage can be analyzed when the p.d.f. of phase is nonuniform as well as uniform.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2454-2459
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• 2008

The objective of this paper is to find out the most effective injection angle for the purpose of deicing through SC/Tetra, a commonly used CFD software. Nowadays, vehicles are developed giving priority to an improved interior which emphasizes a pleasant environment and thermal comfort without decreasing the basic performance. Clear visibility is one of the most important phenomenon. The primary factors which affect the efficiency of deicing are 3D geometry of Defrost Nozzle, the inlet velocity and temperature of the flow and the injection angle. However in this paper, all these parameters are optimized by changing the injection angle. A wide range of injection angle from 5 degree to 50 degree have been considered for analysis. A very good defrosting performance has been achieved with 45 degree injection angle which can satisfy the condition of NHTSA.