• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1011-1013
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• 2003

대개의 Nd형 레이저 광소자는 $^4F_{5/2}$의 준위로 펌핑하여 양자효율이 떨어지며, 소모적 열의 발생으로 마이크로칩 레이저의 높은 펌핑 밀도에 의한 열발생을 유도한다. 그러나 $^4F_{5/2}$ 준위로의 직접 펌핑은 소모적 열발생을 획기적으로 줄일 뿐 아니라 이로 인한 레이저 발진 효율의 증가를 가능하게 하였다. Nd:LSB 마이크로칩 레이저의 경우 공진기 구성에 따라 6-11%의 기울기 효율이 상승하였다.

• Aerospace Engineering and Technology
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• v.4 no.2
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• pp.94-100
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• 2005

The geostationary satellite propulsion system has thermistors which can measure liquid propellant temperature at tanks, pipes and etc. In the satellite propulsion system with several tanks, the propellant in the tanks is moved by temperature change and this temperature pattern is constant. In this paper, the temperature change pattern of KOREASAT 1 propulsion system is compared and the prediction study of pressurant inflow using temperature change of geostationary satellite propulsion system is described.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.52-53
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• 2003

다이오드 레이저의 개발과 발달에 의해 고출력의 다이오드 펌핑 고체 레이저(DPSSL, Doode-Pumped Solid State Laser)가 개발되었고 다양한 분야에서 그 응용성이 증가하고 있다. 고출력 레이저 발생의 경우에 펌핑에 의한 레이저 매질 내부의 열 발생이 중요하게 대두되고, 이러한 열로 인해 레이저 빔의 왜곡이 생겨나 빔질이 저하된다. 레이저 빔질의 개선은 가우시안(Gaussian) 분포를 따르는 빔에 대해 기술하고 있는 광학 공식들과 직접적인 산업현장에서의 유용성 때문에 매우 중요한 문제가 된다. (중략)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.473-487
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• 1995

A loud speaker-driven zero-c.o.p. thermoacoustic refrigerator where an automotive catalytic converter is utilized as a stack has been fabricated and investigated experimentally. Without any heat exchangers at both ends of stack(and thus with zero c. o. p.), temperatures on the stack are measured and various heat transfer rates are calculated from the measured temperatures. Temperatures on the stack have been also calculated numerically using a finite difference method. The measured temperatures are in fair agreement with the calculated temperatures for lower frequency than 300Hz, however, the former deviates from the latter considerably for higher frequency. Two types of c. o. p. have been defined as appropriate to the experiment. While the nominal c. o. p. is zero(the condition in which the pumped heat flow rate in the pore exactly cancels the axial heat conduction down the stack), the true c. o. p. is found to be about 0.14 for 300Hz from the experiments.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.204-209
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• 1990

The temperature variation at a laser rod center induced by high repetetion rate pumping was measured by counting the number of inteference frigne shift and found to be consistent with the theoretical value obtained from heat diffusion equation. The spatial homogeneity and energy transfer rate of flashlamp pumping by the single elliptical reflector plated with gold were evaluated by measuring interference fringes oever the cross section of a Nd:YAG laser rod.

• The Journal of Korean Association of Computer Education
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• v.12 no.5
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• pp.87-94
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• 2009

This paper presents a Web-based interactive and adaptive learning system that helps students learn the pumping lemma for the family of regular languages. Our system allows the students to proceed with their learning according to their individual differences through Web-Based Instruction and gives them opportunities for the interaction so that they can practice exercise related to the learning and gain feedbacks on the results of the exercises immediately. Especially, the system provides adaptive scaffolding that helps learners understand each step for the proof of the pumping lemma. Unlike existing systems that support learning the pumping lemma, the proposed system defines possible errors in advance and provides appropriate messages for corresponding errors. In addition, the system allows the learners to decompose a string into three parts so that they can understand the pumping lemma precisely.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.5-10
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• 2005

The geostationary satellite propulsion system has thermistors which can measure liquid propellant temperature at tanks, pipes and etc. In the satellite propulsion system with several tanks, the propellant in the tanks is moved by temperature change and this temperature pattern is constant. In this paper, the temperature change pattern of KOREASAT 1 propulsion system is compared and the prediction study of pressurant inflow using temperature change of geostationary satellite propulsion system is described.

• Journal of the KSME
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• v.49 no.9
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• pp.22-27
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• 2009

자기냉동 방식은 자석 혹은 자기장을 이용하여 열 에너지 및 엔트로피를 펌핑하고자 하는 노력이다. 이 글에서는 어떻게 자기장을 효과적으로 이용하여 냉동 시스템을 구성할 수 있는지 알아보겠다.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.199-203
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• 1990

원자와 강력한 빛이 상호작용을 하면 섭동이론으로 취급되지 않는 형광선들이 나타나게 된다. Nd:YAG 레이저로 펌핑된 색소레이저를 열 파이프 오븐에 발생시킨 Na 원자 기체의 D1 및 D2 흡수선에 입사시켜 Na 원자를 공명여기 시켰다. 그결과 빛 싸인 원자 모델에서 예측한 7개의 형광선을 얻었고 이들 형광선에 대한 입사광의 세기 및 detuning에 의한 효과에 대해 논의 검토하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.05a
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• pp.120-120
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• 1996