• Nuclear Engineering and Technology
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• v.29 no.4
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• pp.348-359
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• 1997

This paper reviews cooling aspects of the diverter system in Tokamak fusion devices with primary emphasis on the critical heat flux (CHF) issues for oater-cooled designs. General characteristics of four (4) coolant options for diverter cooling gases, oater, liquid metal, and organic liquid - are discussed first, focusing on the comparison of advantages and disadvantages of those options. Then results of recent studies on the high-heat-flux CHF of water at subcooled high-velocity conditions are reviewed to provide a general idea on the feasibility of the water-cooled diverter concept for future Tokamak fusion reactors. Water is assessed to be the most viable and practical coolant option for diverters of future experimental Tokamaks.

• Journal of the Korean Electrochemical Society
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• v.13 no.3
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• pp.181-185
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• 2010

Polyaniline-ionic liquid composite was prepared and investigated its physical and electrochemical properties. The quasi-solidification was presented in imidazolium-based ionic liquid (1-methly-3-propylimidazolium iodide, PMI-I) containing above 30 wt% of polyaniline (emeraldine base), which exhibited around 80% decrease of conductivity compared to pristine ionic liquid, resulting in fibril structure trough ${\pi}-{\pi}$ self-assembled of imidazolium aromatic ring of ionic liquid on polyaniline framework.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.60-63
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• 2007

최근, 핸드폰은 일상생활의 필수품이 되었다. 특히 카메라가 장착된 핸드폰은 개인홍보와 오락요소로의 대표적인 도구로 사용된다. 나아가 양안카메라가 적용된 핸드폰은 사용자에게 입체감을 전달할 것이며, 입체감은 보다 효과적인 개인홍보 및 오락성을 제공할 것이다. 핸드폰은 휴대가 용이하지만 제한된 표시소자의 크기 및 해상도로 인하여 입체시 구현 시 사용자에게 손실된 정보 및 낮은 임장감을 제공한다. 이에 본 연구는 기존의 입체시 구현에 대한 구속조건들을 분석하고 핵심 요인을 산출하여, 핸드폰 환경에서의 최적의 입체시 구현을 위한 새로운 구속조건의 범위를 정량화하였다. 대표적인 구속조건으로는 수평, 수직 시차량이 고려되었다. 본 연구의 결과는 핸드폰용 양안카메라의 제작공차 및 효과적인 시차영상 제작을 위한 기준을 제시한다. 연구에 사용된 제품으로는 QVGA해상도(320*240) 및 2.8' 크기의 표시소자인 PDA폰이며, 입체시에 대한 구속조건을 정량화하기 위하여 수직, 수평이동이 가능한 지그를 사용하여 실험의 정확성을 높였다. 피실험자는 10명이며 남자 7명, 여자 3명으로 구성되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1656-1659
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• 2008

The reflective type color filter for the liquid crystal displays (LCD) was produced using cholesteric liquid crystal monomers whose phase is characterized by the unique optical features of selective reflection. Periodic micrometer scale hemi-spherical photoresist (PR) patterns were formed on glass substrates by thermal reflow method after photolithography. Cholesteric color filter films for red, green and blue light reflections were then produced and the viewing angle dependence was investigated and compared with that of reflected light on the non-patterned substrates.

• Journal of Environmental Impact Assessment
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• v.20 no.1
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• pp.49-59
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• 2011

The results of comparing $PM_{10}$ concentration between 'Namsan' and 'Yongsan-gu' air quality monitoring stations show similar values with averaged concentration in the whole Seoul. The correlation factors in both sites were 0.865, 0.828 in 2005, 2006, respectively. For 'Bukhansan' and 'Gangbuk-gu' air quality monitoring stations, different from the results mentioned above, they showed clear differences as altitude changes. PM10 concentration in 'Bukhansan' monitoring stations was 10 ${\mu}g/m^3$ lower than 'Gangbuk-gu' monitoring station which is located near the ground. Also, averaged PM10 concentration in 'Bukhansan' and 'Gangbuk-gu' monitoring stations was lower than that in the whole Seoul. When comparing $NO_2$ concentration between 'Namsan' and 'Yongsan-gu' monitoring stations, $NO_2$ concentration in 'Namsan' monitoring station was lower than 'Yongsan-gu' monitoring station. For $NO_2$ concentration in 'Bukhansan', 'Gangbuk-gu' and 'the whole Seoul', there were the same pattern in 'Gangbuk-gu' and the 'the whole Seoul' and low values in 'Bukhansan' monitoring station. The correlation factors of $NO_2$ concentration in 'Bukhansan' and 'Gangbukgu' was 0.525, 0.549 in 2005, 2006, respectively, which stands for low correlationship.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.87-100
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• 2018

Fast economic growth and urbanization of China have been causing air pollution not only over its domestic but transboundary atmosphere. Recent high fine particle pollution episodes in China made the government move toward more stringent air pollution control policies - which are mostly fuel switching and emissions control. In this research, we tried to understand characteristics of Chinese emissions and their change by analyzing its emissions inventory by year, sector, and region. From the inter-comparison of existing bottom-up emission inventories, we found relatively good agreements (<20% difference) for $SO_2$ and $NO_x$, but 30% or more discrepancies for some pollutants. Inter-comparison with top-down $NO_x$ emissions estimates also showed 20~50% differences by year. The regional distribution and inter-annual changes of emissions revealed different stages of energy/fuel mix and policy penetration. Early increase of pollutants emissions in the eastern part of China might give strong influences to the Korean peninsular in early 2000s but, more stringent control in that region would help improving air pollution in Korea in near future.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.520-528
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• 2015

The piezoelectric-hydraulic actuator is a hybrid device that consists of a hydraulic pump driven by a piezo-stack coupled to a conventional hydraulic cylinder. The actuator is of compact size, but can produce a moderate energy output. Such hybrid actuators are currently being researched and developed in many industrialized countries due to the requirement for high performance and compact flight systems. In a previous study, we designed and manufactured a unidirectional hybrid actuator. However, the blocking force was not as high as expected. Therefore, in this study, we redesigned the pump chamber and hydraulic cylinder and also improved the system by removing the air bubbles. Two different types of piezo-stacks were used. In order to achieve bidirectional capabilities in the actuator, commercial solenoid valves were used to control the direction of the output cylinder. Experimental testing of the actuator in unidirectional and bidirectional modes was performed to examine performance issues related to driving frequency, bias pressure, reed valve thickness, etc. The results showed that the maximum blocking force was measured as 970.2N when the frequency was 185Hz.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.22-28
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• 2013

Xo2276 is a putative transcription activator-like effector (TALE) in Xanthomonas oryzae pv. oryzae (Xoo). Xo2276 was expressed with a TAP-tag at the C-terminus in Xoo cells to enable quantitative analysis of protein expression and secretion. Nearly all TAP-tagged Xo2276 existed in an insoluble form; addition of rice leaf extracts from a Xoosusceptible rice cultivar, Milyang23, significantly stimulated secretion of TAP-tagged Xo2276 into the medium. In a T3SS-defective Xoo mutant strain, secretion of TAPtagged Xo2276 was blocked. Xo2276 is a Xoo ortholog of Xanthomonas campestris pv. vesicatoria (Xcv) AvrBs3 and contains a conserved DNA-binding domain (DBD), which includes 19.5 tandem repeats of 34 amino acids. Xo2276- DBD was expressed in E. coli and purified. Direct in vitro recognition of Xo2276-DBD on a putative target DNA sequence was confirmed using an electrophoretic mobility shift assay. This is the first study measuring the homologous expression and secretion of Xo2276 in vitro using rice leaf extract and its direct in vitro binding to the specific target DNA sequence.

• Molecules and Cells
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• v.38 no.1
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• pp.89-94
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• 2015

The shape and activity of mitochondria are tightly regulated by fusion and fission processes that are essential for maintaining normal cellular function. However, little is known about the involvement of mitochondrial dynamics in the development of the immune system. In this study, we demonstrate that mitochondrial dynamics play a role in the differentiation and migration of immature dendritic cells (imDCs). We show that mitochondrial elongation is induced during GM-CSF-stimulated differentiation of bone marrow progenitors to imDCs accompanied by upregulation of mitochondrial fusion proteins. These processes precede the changes in mitochondrial morphology and connectivity that occur during differentiation. Mfn2 and OPA1, but not Mfn1, are transcriptionally upregulated during differentiation; however, knockdown of Mfn2 and OPA1 does not induce any change in expression of CD11c, CDC80, or CD86. Notably, knockdown of Mfn2 or OPA1 by siRNA in imDCs significantly reduces CCR7 expression and CCL19-mediated migration. These results suggest that the mitochondrial fusion-related proteins Mfn2 and OPA1 are upregulated during bone marrow progenitor differentiation and promote the migration of imDCs by regulating the expression of CCR7.

• Korean Journal of Remote Sensing
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• v.26 no.1
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• pp.39-45
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• 2010

This study used the keypoint observed simultaneously on two images and on twodimensional intensity image data, which was obtained along with the two point clouds data that were approached for automatic focus among points on terrestrial LiDAR data, and selected matching point through SIFT algorithm. Also, for matching error diploid, RANSAC algorithm was applied to improve the accuracy of focus. As calculating the degree of three-dimensional rotating transformation, which is the transformation-type parameters between two points, and also the moving amounts of vertical/horizontal, the result was compared with the existing result by hand. As testing the building of College of Science at Konkuk University, the difference of the transformation parameters between the one through automatic matching and the one by hand showed 0.011m, 0.008m, and 0.052m in X, Y, Z directions, which concluded to be used as the data for automatic focus.