• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1416-1428
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• 2021

Pebble flow characteristics can be significantly affected by the configuration of pebble bed, especially for HTGR pebble beds. How to achieve a desired uniform flow pattern without stagnation is the top priority for reactor design. Pebbles flows inside some specially designed pebble bed with arc-shaped contraction configurations at the bottom, including both concave-inward and convex-outward shapes are explored based on discrete element method. Flow characteristics including pebble retention, residence-time frequency density, flow uniformity as well as axial velocity are investigated. The results show that the traditionally designed pebble bed with cone-shape bottom is not the most preferred structure with respect to flow pattern for reactor design. By improving the contraction configuration, the flow performance can be significantly enhanced. The flow in the convex-shape configuration featured by uniformity, consistency and less stagnation, is much more desirable for pebble bed design. In contrast, when the shape is from convex-forward to concave-inward, the flow shows more nonuniformity and stagnation in the corner although the average cross-section axial velocity is the largest due to the dominant middle pebbles.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.6
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• pp.552-560
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• 2008

In 1997, Korean government established the National Energy and Resources Plan, which targeted from 1997 to 2005 with strategic energy technology development. At the end of 2005, Korean government built a New National Energy and Resources Plan preparing for upcoming 10 years from 2006 until 2015 based on energy technology trees comparing with the previous plan, which based on the energy R&D projects. In this research, we prioritize the relative preferences and efficiency by an AHP/DEA CCR-I and BCC-I integrated model approach considering scale efficiency for well focused R&D and efficiency of developing Greenhouse Gas technologies as an extended research from a view point of econometrics as an extended research.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.293-298
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• 2012

The purpose of this study is performance validation of district heating apartments about heating energy consumption and analysis of energy consumption by unit characteristics. The heating energy consumption of the existing apartments was analyzed and the analyzed results will be used for energy saving technology development and policy making. The heating energy consumption data about total 78 apartment complexes, 56,910 units in Gangnam-Gu, Seoul, Korea were investigated from October, 2010 to April 2011. The analysis results are as follows; The mean heating energy consumption is 98[kWh/m2]. The energy consumption of Apgujung-Dong, Daechi-Dong is higher than that of mean valuse. The energy consumption deviation by deterioration, unit area, core type and regional group is very high. Specially, building deterioration casts a long shadow.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.1
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• pp.57-63
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• 2017

This study aimed at proposing a RD&D good practice policy guidelines for energy technology innovation in electric power industry, we identified the success factors on energy RD&D through representative case analysis such as energy RD&D demonstration project and strategy plan, technology road map, etc. Based on a successful case study, we have identified the key elements needed to suggest when setting a RD&D technology innovation policy framework for technological competitiveness in the power industry sector. We have presented guidelines for energy technology innovation direction from the full cycle perspective of RD&D. The energy RD&D innovation system that we have established is meaningful in that the implications are derived and reflected through the case analysis of developed countries. The results of this study are as follows; Enhancement of R&D investment performance, commercialization of research achievements, promotion of export industrialization of electric power industry, establishment of RD&D governance system of power energy, etc.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.15-23
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• 2008

The article deals with system technology of a new solar heating system which systematically combines exiting solar collector technology, auxiliary electrical water heating, floor heating system and well insulated construction method and its application of this system to apartment house heating system in the cold region, and also analyzed performance of the new system in terms of technical and economic feasibility. Results shows that energy efficiency approaches up to 50% of the energy consumption of local construction from 1980 to 1981. The implementation of "DQ technology" to floor heating system achieved from 79% to 85% of the energy-saving benefits comparing to other housing units which were supplied by the local district heating plant.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.112-113
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• 2007

We synthesize ZnO nanowires (NWs) doped with 3 wt% Ga on sapphire substrate using a hot-walled pulsed laser deposition (PLD) system named PLD in Furnace. A proprietary target rotating system is employed in the furnace to ensure the homogeneity of the deposition. The kinetic energy of the laser-ablazed ZnO is controlled for the optimization of NW formation. The physical properties of the resultant NWs are presented.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2026-2033
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• 2023

Due to Thailand's nuclear energy public acceptance problem, the understanding of nuclear energy public perception was the key factor affecting to re-consideration of the nuclear energy program. Thailand Institute of Nuclear Technology and its alliances together developed the classification model for the nuclear energy public perception from the big data comments on social media using Facebook using deep transfer learning. The objective was to insight into the Thailand nuclear energy public perception on Facebook social media platform using sentiment analysis. The supervised learning was used to generate up-to-date classification model with more than 80% accuracy to classify the public perception on nuclear power plant news on Facebook from 2009 to 2022. The majority of neutral sentiments (80%) represented the opportunity for Thailand to convince people to receive a better nuclear perception. Negative sentiments (14%) showed support for other alternative energies due to nuclear accident concerns while positive sentiments (6%) expressed support for innovative nuclear technologies.

• Korean Membrane Journal
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• v.9 no.1
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• pp.52-56
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• 2007

A proton exchange membrane was prepared by ${\gamma}-irradiation-induced$ grafting of styrene into poly(tetrafluoro-ethylene-co-perfluoropropyl vinyl ether) (PFA) and subsequent sulfonation reaction. The degree of grafting (DOG) increased with an increase in the absorbed dose. The prepared membranes showed high ion exchange capacity reaching 3.0 meq/g, which exceeded the performance of commercially available perfluorosulfonic acid membranes such as Nafion. The proton conductivity of PFA-g-PSSA membrane increased with the DOG and reached 0.17 S/cm for the highest sample at room temperature. The DMFC performance of the prepared membranes with 50% DOG was comparable to that of Nafion membrane.

• Journal of Radiation Industry
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• v.6 no.4
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• pp.289-297
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• 2012

Since Nafion is very expensive and shows the decreased fuel cell performance over $80^{\circ}C$ operating temperature, much work has been carried out in the search for cheaper membrane with high fuel cell performance. Radiation is known to be very useful for the preparation of the polymer electrolyte membranes since it can be effectively used for the introduction of ion conducting functional groups into the commercial film with high mechanical and chemical properties. Here, we summarize the our recent progress in the development of fuel cell membranes by utilizing radiation.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.29-34
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• 2014

Nanogels are internally cross-linked particles of sub-micrometer size made of hydrophilic polymers and are considered a distinct type of macromolecules, compared with linear and branched polymers or macroscopic gels. In this study, we studied a method of radiation induced synthesis of nanogels, which allows us to obtain tailored intra-molecularly crosslinked macromolecules of independently chosen molecular weight and dimensions. Thus, we report the possibility of applying the prepared nanogels using poly(acrylic acid) through electron beam irradiation for potential application as biomaterials. The nanogels were characterized by scanning electron microscopy (SEM). In addition, the size and zeta-potential of nanogels were measured by a particle size analyzer (PSA). The nanogels were prepared at an approximate size of 180 nm at 100 kGy and were spherical in shapes. The size of the nanogels decreased with increasing irradiation doses, and the absolute value of zeta potential increased with increasing irradiation doses.