• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.880-883
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• 1998

In this paper, sensitivity based approach to estimate BITC(bilateral interchange transfer capacity) considering the real power flow control function of FACTS device is presented. The real power flow setting of the FACTS device is adjusted so that it transfer the power flow from the first violation point of transmission capacity to other transmission lines in the power system, thus allowing more power to be transferred from the specified generator bus to the specified load bus. The transfer between the two bus locations is increased from this new operating condition until a violation of transmission capacity limits occurs or until the setting of the FACTS device can no longer be adjusted. The proposed algorithm is illustrated using examples of small and real life power system.

• Journal of Magnetics
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• 제10권2호
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• pp.48-51
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• 2005

The spin transfer induced magnetization switching has been reported to occur in magnetic multilayer structures whose scope usually consists of one stack of ferromagnetic / non-ferromagnetic / ferromagnetic (F / N / F) materials. In this work, it is shown that: 1) Copper used as a buffer layer between the free Co and the Au cap-layer can clearly increase the probability to get the spin transfer induced magnetization switching in a simple spin valve Co 11 / Cu 6/ Co 2 (nm); 2) Furthermore, when Ruthenium is simultaneously applied as a buffer layer on the Si-substrate, the critical switching currents can be reduced by $30\%$, and the absolute resistance change delta R $[{\Delta}R]$ of that stack can be enlarged by $35\%$. The enhancement of the spin transfer induced magnetization switching can be ascribed to a lower local stress in the thin Co layer caused by a better lattice match between Co and Cu and the smoothening effect of Ru on the thick Co layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.331-334
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• 2000

The organic electroluminescent(EL) device has gathered much interest because of its large potential in materials and simple device fabrication. We fabricated EL devices which have a blended single emitting layer containg poly(Nvinylcarbazole)[PVK] and poly(3-dodecylthiophene)[P3DoDT]. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer between polymer emitting layer and AI electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. Within the molar ratio 1:0, 2:1 and 1:1, the energy transfer was not saturated, which results in the not appearance of PVK emission in the blue region. In the voltage-current and voltage-light power characteristics of devices applied LiF layer, current and light power drastically increased with increasing with applied voltage. In the consequence of the result, the light power of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.54-55
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• 2011

To transfer the power wirelessly, the inverter converted DC power to a high frequency MHz-grade AC power. And the ECR devices for wirelessly transmitting the power are required. In this paper, the spiral-type ECR device and the high frequency inverter were designed. The operating frequency is approximately 1.2MHz. In addition, using a vector network analyzer, the 1.2MHz operating characteristics of the ECR device for wireless power transfer module are analyzed. It is performed and reviewed on validity of wireless power transfer technologies through experiments.

• Membrane and Water Treatment
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• 제1권2호
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• pp.159-169
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• 2010

The effect of external recycle on the performance of dialysis in countercurrent-flow rectangular membrane modules was investigated both theoretically and experimentally. Theoretical analysis of mass transfer in parallel-flow device with and without recycle is analogous to heat transfer in parallel-flow heat exchangers. Experiments were carried out with the use of a microporous membrane to dialyze urea aqueous solution by pure water. In contrast to a device with recycle, improvement in mass transfer is achievable if parallel-flow dialysis is operated in a device of same size with recycle which provides the increase of fluid velocity, resulting in reduction of mass-transfer resistance, especially for rather low feed volume rate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.463-466
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• 2002

In order to examine the possibility of using a cavity as a passive device for reduction of skin friction and heat transfer, an intensive parametric study over a broad range of the cavity depth and length at different Reynolds numbers is performed for both laminar and turbulent boundary layers in the present study. Direct and large eddy simulation techniques are used for turbulent boundary layers at low and moderate Reynolds numbers, respectively. for both laminar and turbulent boundary layers over a cavity, a flow oscillation occurs due to the shear layer instability when the cavity depth and length are sufficiently large and it plays an important role in the determination of drag and heat-transfer increase or decrease. For a cavity sufficiently small to suppress the flow oscillation, both the total drag and heat transfer are reduced. Therefore, the applicability of a cavity as a passive device for reduction of drag and heat transfer is fully confirmed in the present study. Scaling based on the wall shear rate of the incoming boundary layer is also proposed and it is found to be valid in steady flow over a cavity.

• 전기학회논문지P
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• 제58권3호
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• pp.276-284
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• 2009

In this paper, we develop the image transfer remote maintenance monitoring system for hand held device which can compensate defects of human mistake. The human mistakes always happen when the worker communicate information each other to check and maintenance the equipment of the power plant under bad circumstance such as small place and long distance in power plant. A worker couldn't converse with other when in noisy place like Power plant. So, we make some hand device for handy size and able to converse in noisy place. The developed system can have improvement of productivity through increasing plant operation time. And developed system is composed of advanced H/W(hard ware) system and S/W(soft ware)system. The H/W system consist of media server unit, communication equipment with hand held device, portable camera, mike and head set. The advanced s/w system consist of data base system, client pc(personal computer) real time monitoring system which has server GUI(graphic user interface) program, wireless monitoring program and wire ethernet communication program. The client GUI program is composed of total solution program as pc camera program, and phonetic conversation program etc.. We analyzed the required items and investigated applicable part in the image transfer remote maintenance monitoring system with hand held device. Also we investigated linkage of communication protocol for developed prototype, developed software tool of two-way communication and realtime recording skill of voice with image. We confirmed the efficiency by the field test in preventive maintenance of plant power.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.447-448
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• 2012

With wireless power transfer the of ECR device the designed with a high-frequency and high frequency AC power to the device that may enter the high-frequency switching inverter to be possible. In this paper, is designed to 2MHz switching frequency by using ECR device capable of 2MHz Class ${\Phi}_2$ inverter was designed as a wireless power transmission.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.165-170
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• 2004

The purpose of this work was to assess and quantify the beneficial effects of long-term gas exchange, at varying frequencies, for the development of a vibrating intravascular lung assistance device (VIVLAD), for patients suffering from acute respiratory distress syndrome (ARDS). The experimental design and procedure have been applied to the construction of a new device for assessing the effectiveness of membrane vibrations. An analytical solution has been developed for the hydrodynamics of flow through a bundle of sinusoidally vibrated hollow fibers, with the intention of gaining insight into how wall vibrations might enhance the performance of the VIVLAD. As a result, the maximum oxygen transfer rate was reached at the maximum amplitude and through the transfer of vibrations to the hollow fiber membranes. The device was excited by a frequency band of 7Hz at various water flow rates, as this frequency was the 2nd mode resonance frequency of the flexible beam. 675 hollow fiber membranes were also bundled, within the blood flow, into the device.

• 현장농수산연구지
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• 제26권2호
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• pp.25-30
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• 2024

This study was conducted to develop the hanging type circular-patterned system that at maximizing the spatial efficiency of strawberry cultivation to increase yields, while also reducing labor and improving energy efficiency. The system consists of a cultivation bed units, longitudinal moving device, bed lifting device, front and rear transfer devices, lateral transfer device, nutrient supply device, and control unit. Performance testing revealed that the operational motor for longitudinal movement should have a torque of at least 0.1Nm based on the design weight and traction force of the cultivation bed unit. The power consumption required to move one cycle was calculated to be approximately 149Wh when performing harvesting or maintenance tasks for all 10 cultivation beds. Vibration angles measured during bed movement showed that the lateral transfer resulted in a roll angle ranging from -0.62° to 0.68° and a pitch angle ranging from -3.79° to 5.26°. For longitudinal transfer, the roll angle ranged from -3.37° to 3.36°, and the pitch angle ranged from -0.45° to 0.49°.