• Nuclear Engineering and Technology
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• v.39 no.2
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• pp.103-110
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• 2007

The High Temperature Gas-cooled Reactor (HTGR) possesses inherent safety features and is recognized as a representative advanced nuclear system for the future. Based on the success of the HTR-10, the long-time operation test and safety demonstration tests were carried out. The long-time operation test verifies that the operation procedure and control method are appropriate for the HTR-10 and the safety demonstration test shows that the HTR-10 possesses inherent safety features with a great margin. Meanwhile, two new projects have been recently launched to further develop HTGR technology. One is a prototype modular plant, denoted as HTR-PM, to demonstrate the commercial capability of the HTGR power plant. The HTR-PM is designed as $2{\times}250$ MWt, pebble bed core with a steam turbine generator that serves as an energy conversion system. The other is a gas turbine generator system coupled with the HTR-10, denoted as HTR-10GT, built to demonstrate the feasibility of the HTGR gas turbine technology. The gas turbine generator system is designed in a single shaft configuration supported by active magnetic bearings (AMB). The HTR-10GT project is now in the stage of engineering design and component fabrication. R&D on the helium turbocompressor, a key component, and the key technology of AMB are in progress.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.399-407
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• 2011

This study analyzes the performance of hybrid power systems combining a solid oxide fuel cell (SOFC) and a gas turbine (GT). Research focus is given to the influence of the size-dependent gas turbine performance on hybrid system performance. Three hybrid systems adopting different gas turbines (kW, sub-MW, multi-MW classes) are designed. As the gas turbine power increases (i.e. as the gas turbine performance enhances), the gas turbine power portion increases and the hybrid system efficiency increases. The hybrid system shows efficiency improvement over the SOFC only system even in the case where the gas turbine net power is nearly zero. The increase of gas turbine pressure ratio contributes to the net hybrid system power output in all of the three cases, while system efficiency is almost independent on the pressure ratio.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.243-249
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• 2011

Carotenoids were found in high levels in both muscle and tunic samples, with the highest and lowest values observed in March and January, respectively. The average values in muscle (GM) and tunic (GT) harvested in Geoje were 49.1 mg/100g and 56.7 mg/100g, respectively, whereas those in muscle (TM) and tunic (TT) harvested in Tongyeong were 42.0 mg/100g and 50.2 mg/100g, respectively. The total phenol contents of the tunic were not significantly different (P < 0.05) between sampling area and month. We investigated the antioxidative activities of the carotenoids against linoleic acid peroxidation [1,1-diphenyl-2-picrylhydrazyl (DPPH)] and hydroxyl radicals as well as their reducing power. The DPPH radical scavenging activity was 7.6-13.5% in GM, which is relatively weak, whereas it was 21.1-29.9% in GT, 9.6-12.4% in TM and 19.3-24.1% in TT. In comparison to ${\alpha}$-tocopherol, the carotenoids were found to have strong inhibitory effects against linoleic acid peroxidation, and exhibited strong hydroxyl radical scavenging activities and reducing power at 120 ${\mu}g/mL$ of each sample.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.269-275
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• 2005

The engine cooling system for a medium duty V6, 4.5 L diesel engine was modeled with a commercial code, GT-Cool in order to investigate the effect of controllable electric pump on the cooling performance and the fuel economy. The simulation results of the cooling system model with mechanical coolant pump were validated with experimental data. Two different types of electric pumps were implemented into the cooling system model and PID control for electric pump operation was incorporated into the simulation study. Based on the simulation result with electric pump, conventional thermostat hysteresis was modified to reduce pump operation for additional improvement of fuel economy, and then the benefit of electric pumps with modified thermostat hysteresis on fuel economy was demonstrated with the simulation. The predicted result indicates that the cooling system with electric pump and modified thermostat hysteresis can reduce pump power consumption by more than $99\%$ during the FTP 74 driving cycle.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.14-14
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• 2004

• Proceedings of the Safety Management and Science Conference
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• 2004.11a
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• pp.47-51
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• 2004

Facility layout for enterprise's competitive power strengthening and construction of offensive manufacture line and direction presentation for design of production management system that is new by operation improvement according to S company. In enterprise in JIT(Just in Time) system of leading persons affecting in productions among a lot of habitat factor analyze. It is that through equipment Layout among those factors enterprise my problem improve and serves enterprise's absolute ability cultivation. Even if it is JIT production main point that affect to apply the modular production to productive system among at equipment Layout, lot size, bottleneck session etc. worker's multi-function anger, change of demand factor and productive capacity add. 'S' Through enterprise's example, I wish to establish Korean medium and small enterprises' manufacturing industry style equipment Layout model by taken place effect interpretation.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1040-1049
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• 2010

The strengthened regulations for atmospheric emissions from ships have caused a necessity of new, alternative power system in ships for the low pollutant emissions and the high energy efficiency. Recently, new kinds of propulsion power system such as fuel cell system, which use hydrogen as an energy source, have been sincerely considered. The purpose of this work is to predict the performance of methanol fueled SOFC/GT hybrid power system and to analyze the influence of operating temperature of stack, current density of stack, pressure ratio of turbine, temperature effectiveness of recuperator, turbine inlet temperature.

• Journal of radiological science and technology
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• v.38 no.4
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• pp.451-461
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• 2015

In megavoltage (MV) radiotherapy, delivering the dose to the target volume is important while protecting the surrounding normal tissue. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) using an edge block in megavoltage X-ray imaging (MVI). We used an edge block, which consists of tungsten with dimensions of 19 (thickness) ${\times}$ 10 (length) ${\times}$ 1 (width) $cm^3$ and measured the pre-sampling MTF at 6 MV energy. Various radiation therapy (RT) devices such as TrueBeam$^{TM}$ (Varian), BEAMVIEW$^{PLUS}$ (Siemens), iViewGT (Elekta) and Clinac$^{(R)}$iX (Varian) were used. As for MTF results, TrueBeam$^{TM}$(Varian) flattening filter free(FFF) showed the highest values of $0.46mm^{-1}$ and $1.40mm^{-1}$ for MTF 0.5 and 0.1. In NPS, iViewGT (Elekta) showed the lowest noise distribution. In DQE, iViewGT (Elekta) showed the best efficiency at a peak DQE and $1mm^{-1}DQE$ of 0.0026 and 0.00014, respectively. This study could be used not only for traditional QA imaging but also for quantitative MTF, NPS, and DQE measurement for development of an electronic portal imaging device (EPID).

• Journal of Energy Engineering
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• v.25 no.1
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• pp.122-130
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• 2016

This study is a numerical study using commercial simulation program GT-Power on 1.5MW diesel engine for power generation. Performance comparison has done for diesel operation with dual fuel operation for different engine load(50%, 75%, 100%) using the target engine model with additional gas injection system. Effect of using Hi-sene, which is actually being used in island area, instead of diesel was also studied. As a result, under 60% natural gas with diesel condition, BSFC was increased by 32% without modifying system. There was almost no change for natural gas/Hi-sene condition compared with natural gas/diesel condition. Decrease of burned fuel fraction was the main reason of these phenomena. After optimizing system, BSFC was improved by 2%.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.93-100
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• 1995

This study was undertaken to determine whether administration of a standardized gindeng extract at 300 mg.$d^1$ for 8 weeks could enhance maximum aerobic and anaerobic exercise capabilities and whether any changes of such effects can be occurred when exercise training was added. Forty-one male university students were randomly divided into four groups as ginseng-untrained (GU, n=10), ginseng-trained (GT, n=10), placebo-untrained (PU, n=10), and placebo-trained (PT, n=11). The trained groups underwent 8 weeks of aerobic exercise at 65% of individual's maximum oxygen consumption ($Vo_2$ max) for 30 min.$d^1$, 3d.$wk^1$. Prior to and at the end of experiment, $Vo_2$ max, anaerobic power (AP), anaerobic capacity (AC), and leg muscle strength were determined and some physiological parameters related to $Vo_2$ max were measured. Initially, all subject groups did not differ in average $Vo_2$ max (range 45.9 to 47.9 ml/.kg-1.min-1). After 8 weeks, the $Vo_2$ max increased significantly from the initial level by 12.6% in group GU, 14.5% in group PT, and 24.5% in group GU which was significantly higher than group GU but not group PT. Changes in all measured parameters related to $Vo_2$ max were similar among the subject groups except group PU. Both the AP and the AC were significantly increased in all subject groups (range +3.6 to +13.1% above initial for the AP and +4.4 to) 8.955 above initial for the AC) but the higher changes were found for the AP in groups PT and GU, and for the AC in grouts PT, when compared with group PU. No significant differences in the two anaerobic variables were observed between group GT and the other groups of subjects. Leg strength was also significantly enhanced over group PU in groups PT, GU and GT. There were no significant differences among the latter three subject groups. As a result of these findings, it was concluded that under the conditions of this study ginseng administration at the prescribed dose exhibited the training-like effects on $Vo_2$ max as well as anaerobic power and leg muscle strength but no clear synergistic action on these physical fitness variables occurred when both g inseng administration and exercise training were combined.