• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.691-694
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• 2006

So far, we have done much research improving quality of LCD TV. Recently, we have developed 26" WXGA LCD TV by advance fringe field switching (AFFS) technology with smooth and every scene realistic in color image that obtained from the amazing authentic color delivery, optical characteristic and fast response time. Our upgrade device has shown the brightness over 600nits (Color shift <0.015 and Transmittance ratio > 5.5%), gray to gray response time under 6ms, contrast ratio over 1200:1 and viewing angle over 178/178, respectively. And also, motion artifacts improved by fast response of LC with low viscosity, cell gap and dielectric constant.

• 대한기계학회논문집
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• 제18권9호
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• pp.2486-2493
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• 1994

Transient heat transfer characteristics in th radiant heating panel with heat diffusion fin were predicted by numerical analysis. Thermal behaviors of panel, such as temperature distributions in panel and convective and radiative heat fluxes in panel surface with advance of time, were obtained for several important parameters. The performance and thermal comfort of heating panel were studied and compared for various design conditions, such as pipe pitch, area ratio and thermal conductivity of optimal design of the new heating panels with heat diffusion fin. It was concluded that the efficient area ratio of heat diffusion fin is about 0.5, and the greater the thermal conductivity of fin is, the better the performance of panel is.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 추계학술대회논문집
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• pp.174-184
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• 1996

Two methods for cold extrusion processes to produce an axisymmetric steel gear blank are investigated for comparing each other. The "classical" forming method consisting of four operations is selected first to be simulated using the rigid-plastic finite element method and uses single-die presses. The other using a fully automated transfer headers can produce the final part without interannealing. The final products must be checked at the design criteria such as area reduction, the extrusion ratio and punch diameter to depth ratio, especially punch buckling by simulations. FEM analysis is performed mainly for strain distribution, both process sequences are proved to have proper charicteristics suitable for each production method in terms of maximum load. Those simulation results will provide good design criteria in the future work to advance the manufacturing process.

• 한국항공우주학회지
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• 제40권3호
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• pp.193-200
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• 2012

스키점프 공력 특성에 관한 자료 획득을 목적으로 전산 수치 해석을 수행하였다. 한국인의 체형을 고려한 인체 모델링 기법을 적용하였으며 해석 결과의 검증을 위해 기존 풍동실험 연구 결과를 비교 분석하였다. 다양한 비행 조건에서 공력 계수를 분석하여 최대 양항비를 나타내는 비행 자세를 발견하였다. 본 연구가 대한민국 스키점프 선수들의 비행 자세 교정과 국내 스포츠 과학 발전에 기여할 수 있을 것으로 기대한다.

• 한국분무공학회지
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• 제23권2호
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• pp.96-101
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• 2018

The purpose of this study is to investigate the effect of water injection on combustion characteristics of gasoline direct injection (GDI) engine with turbo-charger under low-load operating condition. The test engine used in this study has four-cylinder and 10.2 of compression ratio. In order to study the effect of water injection ratio on combustion characteristics, the water was injected into the intake port from 10% to 50%, based on fuel injection quantity. From the experiment, it revealed that the water injection induced the improvement of fuel economy because of the advance of spark-timing by the reduction of in-cylinder temperature. In addition, the water injection caused the prolong of extension of the ignition delay and slight increase of burn duration.

• 수산해양교육연구
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• 제27권4호
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• pp.1092-1098
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• 2015

Fishing population has been increasing with national income improvement and the five-day workweek in Korea. Recently commercial fishing facilities like pay fishing pond are emerging as demand of saltwater fishing increases, unlike the past when inland fishing was prominent. In order to do businesses, economic analysis should be done in advance. This study aimed to make an Economic analysis of Uljin pay-fishing place by estimating the cost and benefit, and calculating the rate of economic return. The results show the Uljin pay-fishing place's net present value of 3.5 billion won, internal rate of return of 14%, and benefit cost ratio of 1.16 at 5.5% social discount rate.

• 한국산업융합학회 논문집
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• 제3권4호
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• pp.369-378
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• 2000

Conventional fractal image compression methods have many problems in searching time for matching domain block. Proposed method is an improved method of Fisher's Quadtree Decomposition in terms of time, compression ratio, and PSNR. This method determines range block in advance using QR algorithm. First, input image is partitioned to $4{\times}4$ range block and then recomposition is performed from bottom level to specified level. As a result, this proposed method achieves high encoding and decoding speed, high compression ratio, and high PSNR than Fisher's Quadtree Decomposition method.

• 대한기계학회논문집A
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• 제24권6호
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• pp.1540-1546
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• 2000

Recently, force measurement systems are commonly used in many industrial fields and the precision of the measurement system is getting more important as the industry needs more precise tools and in struments to make high quality products. However, a high precision force measurement system is hard to make unless we know precisely the causes, quality and quantity of measurement errors in advance. In this work, many possible mechanical causes of measurement errors are reviewed including ratio of length to diameter of sensing part, radius of contact area, radius of bearing part, ratio of material properties and change of boundary conditions. Also, the measurement errors are analyzed by nonlinear finite element method and the nonlinear behavior of the errors are investigated. The results can be used to design force measurement systems and expected to be very useful especially for compact type load cells.

• Journal of Welding and Joining
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• 제28권6호
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• pp.28-34
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• 2010

This paper was described on investigation to prevent porosity in high speed MIG Welding of Al 6082-T6. Porosity measurement was carried out by using image analysis of micrographs with the help of an analysis software. The main parameter was arc length and torch progressive angle. The porosity ratio was increased as arc length was increased. The arc length was increased depending upon the output voltage. By proper selection of pulse waveform parameter, the stable arc of one pulse one drop was generated. The porosity ratio of optimum condition in one pulse one drop was lower than high voltage condition. When torch progressive angle was an angle of advance $10^{\circ}$, porosity ratio was minium.

• 한국주거학회논문집
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• 제10권4호
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• pp.63-70
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• 1999

The purpose of this study is to evaluate the outdoor environmental quality level at the improvement areas of residence and examine the changes of these areas where the improvement process has been performed. The indicators of outdoor space were examined for case study and several improvement areas were selected and analyzed in terms of these indicators. The improvement areas may be divided into two branch, one is a housing improvement area and the other is a multi-family housing area. The results of this study were as follows; 1) Land-use intensity in both cases was much higher than before. 2) Open space ratio in the housing improvement areas was not enough but in the multi-family housing areas was enough. 3) The road ratio in both cases was much higher. 4) Parking space was not enough to accomodate all the cars in projects. 5) Public facilities and green space did not exist in housing improvement areas but existed a little in multi-family housing areas. In order to improve the environmental quality level, the proper residential density such as dwelling density, open space ratio, land-use intensity should be planned in advance.