• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1215-1219
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• 2009

In this study, the performance of solar assisted hybrid heat pump system with cloud cover were analyzed by using experimental method in spring season. It was consisted of concentric evacuated tube solar collector, heat medium tank, heat storage tank, heat pump, and so on. As a result, the solar radiation should be maintained over $4.1\;MJ/m^2$ in order to operate solar heating system for heating. Solar heat of collector wasn't affected by ambient temperature, but cloud cover has a big effect to collector efficiency. In addition, the collector efficiency is about 50-60%, and solar fraction is 40% for this system.

• Journal of Power Electronics
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• 제6권2호
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• pp.178-185
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• 2006

Recently, the demand for the development of high quality and high-speed laser printers and efficient power utilization has required. Among complicated electro-mechanic devices in laser printers, the toner-fusing unit consumes above 90[%] of all electrical energy needed for printing devices. Therefore, the development of a more effective energy-saving toner fusing process becomes a significant task in great demand. Generally, there are several ways to implement a fusing unit. Among them this paper presents a new induction heating method. The proposed induction heating method enables the increase of coupling coefficient between heating coil and heat roller which also increases total energy transfer efficiency. Therefore, the proposed IH (Induction Heating) inverter system provides very fast W.U.T. (Warm UP Time) as well as higher efficiency. Through experimental results, the proposed control system is verified.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 하계학술발표대회 논문집
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• pp.104-104
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• 2007

• Macromolecular Research
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• 제10권4호
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• pp.194-203
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• 2002

In resin infusion process(RIP), the fiber and the resin are in contact with each other for an impregnation step and often results in flow-induced defects such as poor fiber wetting and void formation. Resin flow characteristics in transverse direction and process modeling for woven fabric were studied, and the process modeling was applied to the manufacturing of hybrid composite materials. This study also considered the compressibility of woven fabrics in a series of compression force, and it was fitted well to an elastic model equation. Void formation was varied with the processing conditions in the stage of manufacturing composites using RIP. It was concluded from this study that proper combination of pressure build-up and dynamic heating condition makes important factor for flow-induced composite processing.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권3호
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• pp.133-139
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• 2003

In this paper, a new control scheme of Class-E inverter for Induction Heating (IH) Jar applications with clamped voltage characteristics using Pulse-Frequency-Modulation (PFM) is introduced. To reduce the voltage stress of switch, the proposed PFM control scheme doesn't need any auxiliary circuit in comparison to a family of Active Clamped Class-E (ACCE) inverter. It can decrease voltage stress of switch through modulation of switching frequency. The Class-E inverter using the proposed control scheme has the advantage of not only the same output power when it is compared with a Hybrid-Active Clamped Class-E (Hybrid-ACCE) inverter but also Zero-Voltage-Switching (ZVS), which are characteristics of conventional Class-E and ACCE inverter. The control principles and analysis of proposed method are explained in detail and its validity is verified through simulation and experimental results.

• 한국주조공학회지
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• 제35권6호
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• pp.141-146
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• 2015

Aluminum-based hybrid parts were fabricated through a compound casting process with Al or Cu inserts which can be used for applications requiring high conductivity. Because the interface stability between the insert and the aluminum matrix is important, the effects of process variables on the interfacial adhesion strength were investigated. Additions of Cu and Mg to Al melt were found to enhance the adhesion strength, though the melt fluidity was slightly deteriorated when a small amount of Mg was added. An isothermal heating process after casting further improved the strength. However AlCu intermetallic compounds formed and their thickness increased during the heating process. As a result, deterioration in the interfacial adhesion strength was observed after an excessive annealing treatment.

• 한국결정학회지
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• 제9권1호
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• pp.44-47
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• 1998

가정용 2.45GHz 마이크로파 오븐을 사용하여 A1 금속분말과 SiO2 분말간에 SHS방법에 의하여 산화/환원 반응을 통한 Al2O3 분말과 Si분말간의 복합체를 얻을 수 있었다. 분말간의 반응을 일으키기 위한 온도까지 승온시키기 위하여는 SiC 분말을 susceptor로 이용한 마이크로파 복합가열(Microwave Hybrid Heating)방법을 사용하여 분당 100℃의 승온 속도로 가열하였으며 반응은 850℃ 근처에서 일어났으며 가열 속도는 반응이 시작되면서 분당 200℃ 이상의 온도상승이 일어나면서 원하는 반응을 얻을 수 있었다.

• The Korean Journal of Ceramics
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• 제6권1호
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• pp.15-20
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• 2000

Thick inorganic-organic hybrid films were prepared on ITO-coated glass substrates by the electrophoretic sol-gel deposition of polyphenylsilsesquioxane particles. The morphology of the deposited films changed from the aggregate of the spherical particles to monolith by heat treatment at temperatures higher than $200^{\circ}C$. Transparency of the films was significantly improved accompanied by the morphological change of the particles. The degree of the morphological change was governed by two factors; maximum heat treatment temperature and heating rate. Transparent thick films of ca. 3$\mu\textrm{m}$ in thickness were obtained only by heat treatment at $400^{\circ}C$ for 2h with rapid heating from room temperature to $400^{\circ}C$. These films obtained were strongly adhered to the ITO-coated glass substrates and has a very smooth surface.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.50-58
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• 2010

Experimental study on the operating characteristics of a solar hybrid heat pump system according to indoor setting temperature were carried out during spring and winter season. The system was consisted of a concentric evacuated tube solar collector, heat medium tank, heat storage tank, and heat pump. As a result, the heating load was increased by 21.1% when the indoor setting temperature rose by 2oC for the same ambient temperature. Besides, the spring season had good outdoor conditions compared to the winter season, therefore the heating load was reduced and heat gain by collector increased, relatively. In case of the winter season, the solar fraction was shown less than 10% because the heat losses of system and space increased considerably. The solar fraction decreased significantly as the indoor setting temperature increased.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.89-94
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• 2008

In this study it was evaluated that hybrid air conditioning and ventilation system to reduce energy consumption and keep on comfortable indoor environment in an underground shopping center. Room temperature by hybrid HAVC system was controled as $1.8{\sim}2.1^{\circ}C$ low and indoor humidity was controled as $4.1{\sim}5.0%RH$ low, and response was fast in $2.0{\sim}2.5$ times compared with conventional system. And also transportation efficiency of hybrid HVAC system was improved in about 27%, and total energy consumption rate of hybrid HVAC system is decreased in 16% compared with conventional system.