• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.142-145
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• 2005

The life expectancy of a transformer largely depends on the temperature-rise it experiences. If the temperature-rise exceeds limits specified in the design standards, the aging of insulating materials is accelerated and the capability of the cooling medium is deteriorated. Consequently, applicable limits for the temperature-rise are essential in designing the transformer and the coolers, demanding the estimation of the transformer's thermal behavior. In order to analyze the temperature characteristics of the transformer, numerical analysis by way of the commercial CFD code has been carried out, and temperature-rise testing to verify computed results was performed. The results obtained in this study show that there is a good agreement between computed outcomes and experimental outcomes.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.1-7
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• 2006

A numerical investigation was performed to determine the effect of airfoil on the optimum flap height using NACA0015 Wells turbine. The five double flaps which have 0.5% difference were selected. A Navier-Stokes code, CFX-TASCflow, was used to calculate the flow field of the Wells turbine. The basic feature of the Wells turbine is that even though the cyclic airflow produces oscillating axial forces on the airfoil blades, the tangential force on the rotor is always in the same direction. Geometry used to define the three dimension numerical grid is based upon that of an experimental test rig. This paper tries to disign the double flap of Wells turbine with the numerical analysis.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.321-328
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• 2004

Since National Geographic Information System was started, topographic maps have been made with computer aided editing of digital map, instead of etching map-size negative film. topographic mapping system's necessity is growing more and more, because digital map has changed into Ver.2.0 which include attributes of feature. On the basis of the previous study for analyzing correlation between the digital map feature code and the 1/5,000 topographic map specifications and trying to develop fundamental modules which will play a core role in topographic mapping system, in this study, we apply some 1/5,000 digital maps Ver.2.0 to topographic mapping system have implemented and try to analyze the result.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.289-295
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• 2015

By adopting a 2D time-dependent wave code, we investigate how mode-converted waves at the Ion-Ion Hybrid (IIH) resonance and compressional waves propagate in 2D density structures with a wide range of field-aligned wavenumbers to background magnetic fields. The simulation results show that the mode-converted waves have continuous bands across the field line consistent with previous numerical studies. These waves also have harmonic structures in frequency domain and are localized in the field-aligned heavy ion density well. Our results thus emphasize the importance of a field-aligned heavy ion density structure for ultra-low frequency wave propagation, and suggest that IIH waves can be localized in different locations along the field line.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.174-174
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• 2004

It is necessary to perform the radionuclide inventory assessment for the disposal of low and intermediate radioactive waste containers. The $\gamma$ nuclide analyzer can be used for the assessment of containers. However, if the radioactivity in the containers is extremely low or high, radionuclide inventory of the containers can not be evaluated properly. Also, gamma scanning method is time consuming and has economical burden to the utilities.(omitted)

• Annual Conference on Human and Language Technology
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• 1989.10a
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• pp.191-196
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• 1989

한글 문서화일을 작성할 때 한글코드로서 일반적으로 많이 사용되는 것은 2 Byte 완성형 코드와 2 Byte 조합형 코드이다. 이 두 코드체제는 각각 내제된 장점이 있으며 이로 인하여 많은 논란이 되어 왔으나, 두 코드체제를 이용하여 작성되는 한글 문서 화일은 여전히 늘어나고 있는 것이 현 실정이다. 이러한 배경에서 한글 문서화일의 코드변환에 관해서는 계속 연구되어 왔고 현재 여러종류의 변환프로그램이 실용화되어 있다. 본 논문에서는 기존의 변환프로그램에서 한글 문서화일을 화일 단위로 변환시키는 것을 표시난 (tag field) 개념을 도입하여 디스크 단위로 변환시킬 수 있도록 개선된 변환프로그램을 제시하였다. 아울러 코드변환시 변환이 필요한 화일을 쉽게 찾을 수 있도록 한글 문서화일에 대하여 그 작성 코드의 종류를 표시할 수 있는 DOS 명령어를 제시하였다.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.44.1-44.1
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• 2015

We set up a project to make spectrometers for single dish observations of the Korean VLBI Network (KVN), a new future multi-beam receiver of the ASTE (Atacama Submillimeter Telescope Experiment), and the total power (TP) antennas of the Atacama Large Millimeter/submillimeter Array (ALMA). Traditionally, spectrometers based on ASIC (Application-Specific Integrated circuit) and FPGA (Field-Programmable Gate Array) have been used in radio astronomy. It is, however, that a Graphics Processing Unit (GPU) technology is now viable for spectrometers due to the rapid improvement of its performance. A high-resolution spectrometer should have the following functions: poly-phase filter, data-bit conversion, fast Fourier transform, and complex multiplication. We wrote a program based on CUDA (Compute Unified Device Architecture) for a GPU spectrometer. We measured its performance using two GPU cards, Titan X and K40m, from NVIDIA. A non-optimized GPU code can process a data stream of around 2 GHz bandwidth, which is enough for the KVN spectrometer and promising for the ASTE and ALMA TP spectrometers.

• Journal of Korea Multimedia Society
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• v.23 no.6
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• pp.765-771
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• 2020

To enable AI(artificial intelligence) to realize visual emotions, it attempts to create music centered on color, an element that causes emotions in paintings. Traditional image-based music production studies have a limitation in playing notes that are unrelated to the picture because of the absence of musical elements. In this paper, we propose a new algorithm to set the group of music through the average color of the picture, and to produce music after adding diatonic code progression and deleting sound using median value. And the results obtained through the proposed algorithm were analyzed.

• Journal of computational fluids engineering
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• v.16 no.1
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• pp.42-47
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• 2011

In this paper, various operating parameters of stream reforming process from methane in stream reformer and preconverter for MCFC is studied by numerical method. Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). The hydrogen production is tested with different wall temperature and different reactor shapes. The calculated results of the concentration of hydrogen in stream reformer are very well consistent with experimental results. This numerical study gives the design reactor wall temperature condition and size of reactor to satisfy the required fuel conversion.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.628-629
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• 2009

A variety of technologies have already been developed to capture energy from the ocean waves, this one is simple to construct. Rather then looking at the surface waves, the technique used lets the waters current beneath the waves directly drive the rotors. The novel ocean wave energy convertor consists of savonius rotor which is mounted in the ocillating water column (OWC) chamber. This study investigates the performance of a 3 blade and 5 bladed savonius rotor under same wave condition using commercial CFD code. Initially the performance analysis of savonius type turbine have been carried out with conventional three bladed curved rotors. From the experieneces of the simulations, 5 bladed savonius rotor have been developed and studied. Performace caracteristics of the 5 bladed savonius rotor has been evaluated and the results obgtained are comopared with the conventional three bladed curved rotors.