• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.97-104
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• 2004

MIRD-type Korean adult male phantom, 'KMIRD' was constructed to calculate Korean-specific dosimetric quantities for radiation protection consideration. The external shape of KMIRD was based on national physical standard data of Korean. KMIRD has thicket trunk than MIRD5 and arm models divided from trunk. The height and weight of the KMIRD are 171 cm and 63.8 kg. ICRP23 data were referred to constitute organs and tissues of KMIRD. However nine organs were constructed based on Korean reference data provided by Radiation Health Research Institute. In the present study, the MCNPX2.3 Monte Carlo transport code was combined with KMIRD to calculate dose conversion coefficients for photon in the energy range from 0.05 to 10 MeV. The simulated irradiation geometries are broad parallel photon beams in AP, PA, LLAT and RLAT direction. Absorbed dose conversion coefficients were compared with data calculated with MIRD5, MIRD-type phantom based on ICRP23 reference man. In some organs, the discrepancies between two phantoms amount up to nearly 30%. The effective doses conversion coefficients of KMIRD are lower than those of MIRD5. The dose discrepancies between two MIRD-type phantoms ate because of physical differences between Korean and Western, also geometric differences between two phantoms. KMIRD should be revised using the full set of Korean reference data of all organs. The developed MIRD-type Korean adult male phantom can be applied to dose assessment of internal exposure.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2002.11a
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• pp.191-194
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• 2002

매체 순환식 연소(Chemical-Looping Combustion, CLC)는 금속 산화물(산소공여매체, oxygen carrier)의 산소를 이용하여 화석연료를 산화(연료 연소 공정)시키고, 환원된 금속을 다시 산화(매체 산화 공정)시키는 간접적인 연소 공정의 하나이다. 이 방식은 온실효과의 주발생원인 $CO_2$를 원천적으로 회수할 수 있고, 또한 화염이 없는 상태에서 연소반응이 진행됨으로 thermal NOx의 발생을 미연에 방지할 수 있어 고효율의 환경친화적인 연소공정이다.(중략)

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.219-221
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• 2009

In this paper, we present stereoscopic conversion based on movie shot information. To overcome the low stereoscopic quality of automatic stereo conversion technologies, the usage of the shot type is expected to provide more satisfactory stereoscopic perception. In general, movie clips are produced with a variety of shot techniques such as long shot, closeup shot, medium shot, etc. Each shot has its own characteristics that can be utilized during the conversion process. Furthermore, description sceme for shot and camera information is presented in XML. XML shot editor generates XML shot data. and conversion module parses such data and converts 2D image into stereoscopic image.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.5C
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• pp.522-529
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• 2002

MMIC circuits in whole receiver system was fabricated based on GaAs pHEMT technology. And a V-band downconverter module was fabricated by integrating these circuits. The downconverter module consists of a LO drive power amplifier which generates 24dBm output power, a low noise amplifier(LNA) which shows 20 dB small signal gain, an active parallel feedback oscillator which generates 1.6 dBm output power, and a cascode mixer which shows over 6dB conversion gain. The good conversion gain performance of our mixer made no need to attach any IF amplifier which grows conversion gain. Measured results of the complete downconverter show a conversion gain of over 20 dB between 57.5 GHz and 61.7GHz without IF amplifier.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.4
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• pp.355-363
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• 2014

Thermal shock or overheating of WGS catalyst for SEWGS system during hydrogen pre-treatment can cause reactivity decay of the catalyst. To select appropriate pre-treatment condition, temperature profiles of catalyst bed (or outside fluidized particle bed of bed insert) during pre-treatment were measured and then CO conversions of those catalysts during WGS reaction were also measured and compared. Drastic overheating of catalyst took place when we reduce catalyst at fixed bed condition and these catalysts showed low CO conversion during WGS reaction. On the contrary, there was no overheating of catalyst at fluidized bed condition not only physical mixing case but also bed insert case. Spring type bed insert showed acceptable CO conversion even at low WGS content. Consequently, feasibility of high CO conversion without decay of reactivity of catalyst and holding the WGS catalyst inside the SEWGS reactor as tablet shape were confirmed using spring type bed insert.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.990-1000
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• 2012

In this paper, we propose an algorithm that creates three-dimensional (3D) stereoscopic video from two-dimensional (2D) video encoded by H.264 instead of using two cameras conventionally. Very accurate motion vectors are available in H.264 bit streams because of the availability of a variety of block sizes. 2D/3D conversion algorithm proposed in this paper can create left and right images by using extracted motion information. Image type of a given image is first determined from the extracted motion information and each image type gives a different conversion algorithm. The cut detection has also been performed in order to prevent overlapping of two totally different scenes for left and right images. We show an improved performance of the proposed algorithm through experimental results.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.237.2-237.2
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• 2010

Although oscillating water column type wave energy devices are nearing the stage of commercial exploitation, there is still much to be learnt about many facets of their hydrodynamic performance. The techniques of Computational Fluid Dynamics (CFD) are applied to simulate a wave energy conversion device in free surface such as waves. This research uses the commercially available ANSYS CFX computational fluid dynamics flow solver to model a complete oscillating water column system with savonius turbine incorporated at the rear bottom of the OWC chamber in a three dimensional numerical wave tank. The purpose of the present study is to investigate the effect of an average wave condition on the performance and internal flow of a newly developed direct drive turbine (DDT) model for wave energy conversion numerically. The effects of blade angle and front lip shape on the hydrodynamic efficiency are investigated. The results indicated that the developed models are suitable to analyze the water flow characteristics both in the chamber and in the turbine. For the turbine, the numerical results of torque were compared for the all cases. The results of the testing have also illustrated that simple changes to the front wall aperture shape can provide marked improvements in the efficiency of energy capture for OWC type devices.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.1
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• pp.25-33
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• 1998

We have studied the reduction of NO by propane over perovskite-type oxides prepared by malic acid method. The catalysts were modified to enhance the activity by substitution by substitution of metal into A or B site of perovskite oxides. In addition, the reaction conditions, such as temperature, $O_2$ concentration, space velocity have been studed. In the $LaCoO_3$ type catalyst, the partial substitution of Ba, Sr into A site enhanced the catalytic activity in the reduction of NO. In the $La_{0.6}Sr_{0.4}Co_{1-x}Fe_xO_3(x=0 \sim 1.9)$ catalyst, the partial substitution of Fe into B site enhanced the conversion of NO, but excess amount of Fe decreased the conversion of NO. The surface area and catalytic activity of perovskite catalysts prepared by malic acid method showed higher values than those of solid reaction method. In the $La_{0.6}Sr_{0.4}Co_{1-x}Fe_xO_3$ catalyst, the conversion of NO increased with increasing $O_2$ concentration and contact time. The introduction of water into reactant feed decreased the catalytic activity.

• The Journal of Korean Medicine
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• v.22 no.3
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• pp.31-41
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• 2001

Objectives : This study was performed to investigate the effects of Cordyceps Sinensis (CS) and Cordyceps Militaris (CM) on anti oxidation in the livers of ${CCl_4}-treated$ rats. Methods : Hepatotoxicity in rats was induced by carbon tetracWoride. $CCl_4-induced$ rats were administered with the extract of CS and CM. Results : In vitro, CS and CM didn't affect levels of lipid peroxide and the activities and type conversion ratio of xanthine oxidase. However, hydroxyl radicals and DPPHL radicals were decreased. In vivo, in the ${CCl_4}-treated$ rats, lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were increased but superoxide dismutase was decreased. After CS and CM were administered to ${CCl_4}-treated$ rats, levels of lipid peroxide, the activities and type conversion ratio of xanthine oxidase and superoxide radicals were decreased but superoxide dismutase was increased. Conclusions : These results suggest that CS and CM decrease the activities of free-radical-generating enzymes which form lipid peroxide and increase the activities of oxygen free radical scavenging enzymes.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.167-180
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• 1999

Cervus elaphus, being known to reinforce Kidney, have tested to study the effects concerning damages of brain tissue induced by lipid peroxidation. In vitro, the level of lipid peroxide in brain tissue was decreased proportinally according to dose by Cervus elaphus extract solution for aqua-acupuncture (CESAA). It was much more decreased, when lipid peroxidation was induced with Fe(II). And, it was seen proportinally decrease according to the dose of CESAA on xanthine oxidase activities and type conversion ratio. However, I can not find special changes about aldehyde oxidase activities. And, I had observed the effects of CESAA on damages of rat's brain following ischemia and reflow. Before ischemia was caused, CESAA was applied 0.2 ml per 250 g through femoral vein in ischemia and reflow group and normal sailine was applied in normal group. Ischemia was caused by cervical artery's clamp for 30 min and reflowed by clamp remove after 15 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. However, they were decreased when CESAA was pre-appllied. However, it could not seen special changes on aldehyde oxidase activities, either. In conclusion. CESAA recovers the damage of brain due to ischemia and reflow by decreasing the lipid peroxidation through decreasing of xanthine oxidase activies and type conversion ratio.