• 한국자동차공학회논문집
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• 제19권5호
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• pp.134-142
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• 2011

Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Exhaust pipes with circular fin were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NOx), carbon dioxide ($CO_2$) and carbon monoxide (CO). In addition, $O_2$ concentration in the exhaust was measured. The designs adopted in this study were about exhaust pipes with solid and hollow fins around them direct surface force measurement in water using a nano size colloidal probe technique. The direct force measurement between colloidal surfaces has been an essential topic in both theories and applications of surface chemistry. As particle size is decreased from micron size down to true Carbon nano Colloid size (<10 nm), surface forces are increasingly important. Nano particles at close proximity or high solids loading are expected to show a different behavior than what can be estimated from continuum and mean field theories. The current tools for directly measuring interaction forces such as a surface force apparatus or atomic force microscopy (AFM) are limited to particles much larger than nano size. This paper use Water and CNC fluid at normal cooling system of EGR. Experimental result showed all good agreement at Re=$2.54{\times}10^4$ by free convection and Re=$3.36{\times}10^4$ by forced air furnace.

• 한국광학회지
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• 제13권6호
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• pp.506-509
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• 2002

새로운 방법으로 간편하게 입체적으로 비디오 영상을 촬영할 수 있는 광학계를 설계하였다. 광학계의 전체 시야는 42$^{\circ}$이고 유효경은 22mm이다. 본 광학계를 비디오 카메라나 캠코더에 장착하여 정립 실상으로 입체 영상을 촬영하고 이를 입체 영상으로 재생할 수 있는 2중 무초점계 bi-ocular형이다. 광학계의 크기는 광로정을 광속분리기 및 평면경으로 접어서 compact하게 축소되었다. 광학계는 4개의 렌즈군으로 구성되며 각 렌즈군은 relay 렌즈 역할까지 겸하여 v근netting효과를 최소화하였기 때문에 전체 시야에 걸쳐 거의 광 손실 없이 영상을 정립 실상으로 비디오 카메라나 캠코더 렌즈에 전달하고 있다 전 시야에 걸쳐 양 쪽 눈에서 볼 수 있는 영상을 서로 수직한 방향의 편광자와 chopper를 이용하여 1초에 30개 이상 교대로 녹화한다. 재생할 때는 서로 수직한 방향의 편광자를 가진 입체시 안경을 쓰고 양쪽 눈으로 각각의 영상을 보게 되며 입체영화를 감상할 때와 같이 잔상효과로 인하여 연속적인 입체 동영상으로 감상할 수 있다.

• KIEAE Journal
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• 제3권3호
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• pp.19-25
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• 2003

The Address No.0 of Eco-friendly Architecture offers unique experience for those who visit the place to envisage the future architecture where nature, human and building exist in harmony. It is open to the general public including the students of elementary and secondary schools. This house has been built to provide opportunities for the general public to experience eco-friendly architecture. It's floor area is 42 pyung($140m^2$) and the overall site has the area of 180 pyung($600m^2$). The following illustrates some of its prominent features : ${\bullet}$ Remodeling of a traditional Korean residence ${\bullet}$ Application of passive solar systems ${\bullet}$ Use of clerestory windows and daylighting systems(washroom and machine room) ${\bullet}$ Operation of solar water heaters with flat plate collectors ${\bullet}$ Construction of Biotop(small ecological world) ${\bullet}$ Water circulation for Biotop by photovoltaic(150W) and wind power(400W) generation ${\bullet}$ Outdoor hot water supplied by all-glass evacuated solar tubes. Through this Address No.0 of Eco-friendly Architeture conclusions are as followings. 1. The array of tubes in collector has the best nice in that the number of tube is nine and the tilt angle is the latitude $+20^{\circ}$. 2. The thermal performance of the all-glass solar vacuum collector was excellent than of the flate-plate solar collector. 3. The adaption of new small wind power systems to buildings were proved to produce a profit if it is considered the expense of environment improvement and the wind speed increasing according to rise of building hight.

• 대한방사선기술학회지:방사선기술과학
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• 제4권1호
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• pp.55-62
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• 1981

This study was conducted, during the period of 20-30th, July in 1981, to survey measurement methods in thyroid uptake rate test in Seoul city. The results were summarized as follows: 1. For the great part of nuclear medcine department, a mount of radioiodine($^{131}I$) administrated to the patients was $50-100{\mu}Ci$ in thyroid uptake rate test. 2. Distribution of scintillation, counter with crystal size of $1\frac{1}{2}inch$ was 43%, 3inch(22%), 2.5inch(14%) and $2\frac{1}{2}inch$ was 7% in RAI uptake rate test. 3. When RAI uptake rate test was performed, distribution of collimator in use was flat field type collimator(78%) in general and cylindrical type collimator was 22%. 4. High voltage applied to the P-M tube was $900{\sim}1000V$(50%) and most units provided $3{\sim}15%$ of the window range for the $^{131}I$ peak $\gamma-ray$ energy. 5. Distribution on the use of neck phantom for measurements standard solution was 57% and distribution of b filter in use for room background counts and extrathyroidal tissue was 43% and 50%. 6. The distance between the counter and the source was 25cm(58%) in measuring radioactivity of standard solution, thyroid tissue and background radioactivity count. 7. The early uptake measurements(2, 4, 6 hours) are done after administration of the radioiodine dose and also 24-hour and 48-hour uptake measurements are done in routine test.

• 화훼연구
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• 제17권3호
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• pp.197-200
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• 2009

접목선인장 신품종 '고홍'은 진적색의 'DR' 계통을 모본으로 진적색의 '설홍'을 부본으로 2004년에 교배하여 개발되었다. 이 품종은 처음 기내에서 파종한 후 유묘를 무병삼각주에 접목하고 100 mL 시험관에 정식하여 6개월을 재배하였다. 2005년에 기외에서 접목한 후에 2008년까지 3회에 걸쳐 그 특성이 조사되었다. 구는 진적색의 편원형이며, 몸체에 8~10개의 결각이 있으며, 회색의 직립 가시를 가지고 있다. 구의 직경은 44.1 mm로 대조 품종 '설홍'에 비해 구가 크고 생육 속도도 빠르다. 지구 착생수는 평균 12.1개로 12.2개의 대조 품종 '설홍'과 유사하다.

• 화훼연구
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• 제19권4호
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• pp.248-250
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• 2011

비모란 선인장 '이홍' 품종은 진적색의 계통 'DR'을 모본으로 진적색의 '설홍' 품종을 부본으로 2005년 교배하여 개발되었다. 파종된 종자는 기내에서 접목되어 6개월 동안 100 mL 시험관에서 6개월 동안 자랐다. 2006년 재접목되어 온실에 정식되어 2009년까지 다양한 특징이 조사되었다. 편원형의 모양과 진적색의 구색을 가지고 있으며, 또한, 8-10개의 결각과 갈색의 직립형 가시를 가지고 있다. 온실에 정식 후 10개월째에 '이홍' 품종의 구직경은 44.0 mm였으며 '설홍' 품종에 비해 큰 편이었다. 자구수는 10개월째에 15.8개로 '설홍' 품종에 비해 많았으나 유의성은 없었다.

• 화훼연구
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• 제16권3호
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• pp.196-199
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• 2008

접목선인장 신품종 '다홍'은 흑적색의 '9508021'계통을 모본으로 진적색의 '진홍'을 부본으로 2002년에 교배한 후대이다. 2003년 기외에서 접목한 후에 2006년까지 3회에 걸쳐 그 특성이 조사되었다. 구는 진적색의 편원형이며, 가지자리에 같은 색의 자구가 모구하부에 정연히 착생된다. 또한 몸체에 8~10 결각이 있으며, 회색의 반직립 가시를 가지고 있다. 자구 착생수는 평균 13.6개로 10.4개의 대조품종 '진홍'보다 우수하였다.

• 화훼연구
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• 제18권4호
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• pp.291-294
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• 2010

접목선인장 신품종 '황운'은 해외 수출용 목적으로, 황색과 오렌지색을 가진 복색의 '황월' 품종을 모본으로 황색의 계통 '0111021'을 부본으로 교배하여 2008년에 개발되었다. 이 품종은 처음 기내에서 무병삼각주에 접목된 후 100 mL 시험관에 정식되어 6개월간 생육되었다. 2005년에 기외에서 접목한 후에 2008년까지 3회에 걸쳐 그 특성이 조사되었다. 구는 황색의 편원형이며, 몸체에 7~9개의 결각이 있으며, 갈색의 직립형 가시를 가지고 있다. 10개월간 재배되었을 때 구의 직경은 40.9 mm로 대조 품종 '후광'에 비해 구가 작고, 자구 착생수는 평균 22.3개로 '후광' 품종에 비해 우수하였다.

• ETRI Journal
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• 제41권1호
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• pp.23-31
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• 2019

Since the late 20th century, there has been rapid development in the display industry. Only 30 years ago, we used big cathode ray tube displays with poor resolution, but now most people use televisions or smartphones with very high-quality displays. People now want images that are more realistic, beyond the two-dimensional images that exist on the flat screen, and digital holography-one of the next-generation displaysis expected to meet that need. The most important parameter that determines the performance of a digital hologram is the pixel pitch. The smaller the pixel pitch, the higher the level of hologram implementation possible. In this study, we fabricated the world-smallest $3-{\mu}m$-pixel-pitch holographic backplane based on the spatial light modulator technology. This panel could display images with a viewing angle of more than $10^{\circ}$. Furthermore, a comparative study was conducted on the fabrication processes and the corresponding holographic results from the large to the small pixel-pitch panels.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.655-668
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• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.