• 대한전기학회논문지
• /
• 제32권2호
• /
• pp.59-64
• /
• 1983

This paper deals with the transient energy method of transient stability analysis of multi-machine power system by improving the transfer conductance, the kinetic energy and the critical transient energy. The tranfer conductance is considered more correctly, the generators of system are seperated to two states (critical and the rest state)and the correction term of critical transient energy (to reference point) is added. This analysis is performed by digital computer simulation and the application of this method to two model systems has shown its superiority to other available methods.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.606-609
• /
• 1999

We fabricated white light-emitting diode which have a mixed single emitting layer containing poly(N-vinylcarbazole), trois(8-hydroxyquinoline)aluminum and poly(3-hexylthiophene) and investigated the emission properties of it. It is possible to obtain a blue light from poly(N-vinylcarbazole). green light from tris(8-hydroxyquinoline)aluminum and red light from poly(3-hexylthiophene). The fabricated device emits white light with slight orange light. We think that the energy transfer in a mixed layer occurred from PVK to Alq₃ and P3HT resulted in decreasing the blue light intensity from PVK. We find that the efficiency of the white light electroluminescent device can be improved by injecting electron more effectively and blue light need to improve the color purity of white light.

• 한국해양공학회지
• /
• 제2권2호
• /
• pp.130-137
• /
• 1988

This thesis introduced that character of a treatment technique for a mading synthetic resin Hifiow-Ring. The material system of packings make an experiment air$NH_{3}$/air$H_{2}SO_{4}$, $SO_{2}$-air/NaOH, $NH_{3}$-air/$/H_{2}SO_{4}$ under general conditions. Lattices packing compared with conventional packings was proved low pressure loss and high separation efficiency for high loading per trans unit. And an inflow materal tested for absorption and rectification, it made an experiment under a range regular temperature, low energy and small amount of money. That made possible in simple equation, volume material tranfer coefficient$\beta_{L}$ . a by absorption or $\beta_{V}$ .a calculated in all range loading. The peculiarity pressure loss $\Delta\;P/NUT_{ov}$ for Hiflow-ring contributed to a fall cost of energy, a grade number of a vacuum rectification and absorption calculation.

• 한국태양에너지학회 논문집
• /
• 제25권1호
• /
• pp.45-55
• /
• 2005

In the summer, the irradiated solar heat gain through the roof has an effect on the thermal environment of the top floor units of apartment houses. This paper investigated the differences of the indoor air temperature, globe temperature and thermal comfort index between the top floor unit and the middle floor unit by measuring them at the sample units on the condition that all the openings of the units are opened. The purpose of this paper is to provide quantitative data about the irradiated solar heat gain during the summertime through the roof of an apartment house and these data to be the source to reevaluate the appropriate roof insulation efficiency. From this study, we obtained three brief results as follows. Indoor air temperature difference between the two sample units shifts a day. Indoor air temperature at the top floor unit is $0{\sim}1.8^{\circ}C$ higher than that of the middle floor unit from 12:00 p.m. to 12:00 a.m. and $0{\sim}2.8^{\circ}C$ lower from 12:00 a.m. to 12:00 p.m. The evaluation of the indoor thermal comfort index and the globe temperature shows similar results as the indoor air temperature measuring. Results of this experiment verified the actual existence of indoor air temperature difference between the top floor unit and the middle one and this difference comes from the heat storage of the roof.

• 한국재료학회지
• /
• 제2권4호
• /
• pp.279-284
• /
• 1992

고분해능 전자에너지손실 및 자외선광전자 분광법을 사용하여 단결정 NbC(111)면의 산소횹착을 연구하였다. NbC(111) 표면에는 산소가 원자 및 분자상태로 흡착되었다. 산소원자는 3-fold hollow site에 흡착되며 진동수는 548c$m^{-1}$이었다. 산소분자의 신축진동수는 968c$m^{-1}$로서 기체상태인 산소분자의 진동수보다 크게 낮았으며, 산소분자의 흡착으로 일함수가 증가하였다. 이는 NbC(111) 기판으로부터 산소분자의 2p${pi}_g$ 궤도로 전자가 이동하였음을 보여주는 증거이다.