• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.117-122
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• 2008

The apartment will be much more convenient than the other one in the application of green technologies, providing the merits by mass production. For example, pre-manufactured building materials can be effectively adapted to the formation of buildings. Recently, the form of double-enveloped window system has been developed for the purposed of minimizing energy loss occurred around windows. On the other hand, the expansion of balcony area was legalized and thus, a visual buffer area does not exist any more. All-glass window wall on apartment houses without a balcony produces pretty harmful area with direct sunbeam. A various types of glass can be applied to the window system and it plays a critical role in the determination of inner visual environment. For the purpose of verifying the potential of its daylighting, a mock-up model has been constructed and tested. The refurbished version of conventional window shows its illuminated characteristics. Clear and Low-e glass have been adapted for window area and daylighting ratio has been compared in both test cells.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.336-339
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• 2009

In this paper, such as battery power or solar energy and fuel cells generated from Renewable energy sources, high voltage to low voltage DC-DC Converter for converting the design of the study. System consists of low voltage ($24{\sim}28$ [VDC]) and Boosts the voltage (270 [VDC]) for a 3 [kW] DC-DC converter and control circuit is configured as, Power switch the ST Tomson's Automotive low voltage high current MOSFET switches STE250NS10S (temperature 250A) was applied to the two parallel. Also, Controller's processor used ATMEGA128, and Gate Drive applies and composed Photo Coupler TLP250. development. Input voltage (24V) and output voltage (270V) for Conversion in the H-bridge converter topology of the circuit output side power and voltage to control the implementation of the Phase shift angle control applied. And, 3kW of power to pass appropriate specification of the secondary side as interpreted by the high frequency transformer, and the experimental production and analysis of the experiment

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.1-15
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• 2020

Nuclear power plants in South Korea are operated to cover the baseload demand. Hence they are operated at 100% rated power and do not deploy power tracking control except for startup, shutdown, or during transients. However, as the contribution of renewable energy in the energy mix increases, load follow operation may be needed to cover the imbalance between consumption and production due to the intermittent nature of electricity produced from the conversion of wind or solar energy. Load follow operation may be quite challenging since the operators need to control the axial power distribution and core reactivity while simultaneously conducting the power maneuvering. In this paper, a systems engineering approach for multi-physics load follow simulation of APR1400 is performed. RELAP5/SCDAPSIM/MOD3.4/3DKIN multi-physics package is selected to simulate the Korean Advanced Power Reactor, APR1400, under load follow operation to reflect the impact of feedback signals on the system safety parameters. Furthermore, the systems engineering approach is adopted to identify the requirements, functions, and physical architecture to provide a set of verification and validation activities that guide this project development by linking each requirement to a validation or verification test with predefined success criteria.

• New & Renewable Energy
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• v.18 no.4
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• pp.64-69
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• 2022

Double-sided photovoltaic (PV) modules have received significant attention in recent years as a technology that can achieve higher annual energy production rates than single-sided modules. The shingled technology is a promising method for manufacturing high-density and high-power modules. These modules are divided by laser and joined with electrically conductive adhesives. The output efficiency of the divided cells depends on the division pattern and the electrode pattern, making it important to understand the output characteristics. In this study, the output characteristics of large-area double-sided light-receiving shingled cells with different split patterns and electrode patterns were investigated. The M6 size, with 6 divisions in the electrode pattern, had the highest efficiency when using 142 front fingers and 146 rear fingers. The M10 size, with 7 divisions, had the highest output when using 150 fingers equally in the front and rear. The M12 size, also with 7 divisions, showed the highest output characteristics when using 192 front fingers and 208 rear fingers.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.31-40
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• 2014

The Korean government made the 2nd Energy Basic Plan to achieve 11% of new and renewable energies distribution rate until 2035 as a response to cope with international discussion about greenhouse gas emission reduction. Renewable energies include solar thermal, photovoltaic, bioenergy, wind power, small hydropower, geothermal energy, ocean energy, and waste energy. New energies contain fuel cells, coal gasification and liquefaction, and hydrogen. As public and private investment to enhance the distribution of new and renewable energies, it is necessary to clarify the economic effects of the new and renewable energies sector. To the end, this study attempts to apply an input-output analysis and analyze the economic effects of new and renewable energies sector using 2012 input-output table. Three topics are dealt with. First, production-inducing effect, value-added creation effect, and employment-inducing effect are quantified based on demand-driven model. Second, supply shortage effects are analyzed employing supply-driven model. Lastly, price pervasive effects are investigated applying Leontief price model. The results of this analysis are as follows. First, one won of production or investment in new and renewable energies sector induces 2.1776 won of production and 0.7080 won of value-added. Moreover, the employment-inducing effect of one billion won of production or investment in new and renewable energies sector is estimated to be 9.0337 persons. Second, production shortage cost from one won of supply failure in new and renewable energies sector is calculated to be 1.6314 won, which is not small. Third, the impact of the 10% increase in new and renewable energies rate on the general price level is computed to be 0.0123%, which is small. This information can be utilized in forecasting the economic effects of new and renewable energies sector.

• Advances in Energy Research
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• v.4 no.2
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• pp.121-146
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• 2016

This study is concerned with the analysis of two renewable technologies for electric energy production: wind energy and photovoltaic energy. The two technologies were assessed and compared by economic point of view, by using selected indicators characterized by a clear calculation approach, requirement of information easy to be collected, clear, but even complete, interpretation of results. The used economic indicators are Levelized Cost of Energy, $CO_2$ abatement cost and fossil fuel saving specific cost; these last two specifically aimed at evaluating the different capabilities that renewable technologies have to cut down direct $CO_2$ emissions and to avoid fossil fuel extraction. The two technologies were compared also from the environmental point of view by applying Life Cycle Assessment approach and using the environmental impact categories from the Eco-indicator'95 method. The economic analysis was developed by taking into account different energy system sizes and different geographic areas in order to compare different European conditions (Italy, Germany and Denmark) in term of renewable resource availability and market trend. The environmental analysis was developed comparing two particular types of PV and wind plants, respectively residential and micro-wind turbine, located in Italy. According to the three calculated economic indicators, the wind energy emerged as more favorable than PV energy. From the environmental point of view, both the technologies are able to provide savings for almost all the considered environmental impact categories. The proposed approach, based on the use of economic and environmental indicators may be useful in supporting the policies and the decision making procedures concerned with the promotion and use of renewables, in reference to the specific geographic, economic and temporal conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.593-602
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• 2020

Recently, as research on smart farms has been actively conducted, systems for efficiently cultivating crops have been introduced and various energy systems using renewable energy such as solar, geothermal and wind power generation have been proposed to save the energy. In this paper, we propose a new and renewable energy convergence system for crops that provides energy independence and improved crop cultivation environment. First, we present LPWA-based communication node and gateway for ICT-based data collection. Then we propose an integrated monitoring server that collects energy data, crop growth data, and environmental data through a communication node and builds it as big data to perform optimal energy management that reflects the characteristics of the environment for cultivating crops. The proposed system is expected to contribute to the production of low-cost, high-quality crops through the fusion of renewable energy and smart farms.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.432-437
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• 2022

In this study, strawberries were grown during the two cultivation periods (first: 2020-2021, second: 2021-2022) to analyze the effect of the external light environment and growing degree days (GDD) on crop production. The temperature and humidity during day in a greenhouse in each cultivation period were similarly managed. At night, there was a statistical difference in temperature and humidity in the greenhouse between two periods. The accumulated solar radiation during the first cultivation period was high in September and October. Since January, the accumulated solar radiation during the second cultivation period was high. In the second cultivation period, the initial yield was small because the accumulated solar radiation and GDD was small. But accumulated yields and potential maximum yields in second cultivation period were larger than yields in the first cultivation period as the accumulated solar radiation and GDD increased. The sugar contents of strawberry decreased as GDD increased.

• Korean Chemical Engineering Research
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• v.43 no.3
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• pp.331-343
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• 2005

Development of hydrogen station system is an important technology to commercialize fuel cells and fuel cell powered vehicles. Generally, hydrogen station consists of hydrogen production process including desulfurizer, reformer, water gas shift (WGS) reactor and pressure swing adsorption (PSA) apparatus, and post-treatment process including compressor, storage and distributer. In this review, we investigate the R&D trends and prospects of hydrogen station in domestic and foreign countries for opening the hydrogen economy society. Indeed, the reforming of fossil fuels for hydrogen production will be essential technology until the ultimate process that may be water hydrolysis using renewable energy source such as solar energy, wind force etc, will be commercialized in the future. Hence, we also review the research trends on unit technologies such as the desulfurization, reforming reaction of fossil fuels, water gas shift reaction and hydrogen separation for hydrogen station applications.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.180-185
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• 2014

Due to the larger and high-speed vessels recently constructed, output and speed of the engines for propulsion or power generation is increasing. These high-power and high-speed engine of the ship is becoming as a major contributor causing excessive noise and vibration. Other fittings as well as equipment installed on board, it makes equipment failure or other defect by resonance. This causes a lot of M/H(Man Hour) for repairs and the reliability of the company is invading even be negative because the clients give much comment. Thus, it's being studied for any fittings installed on board to maintain the safe operation and to prevent any problem during the performance in any operating conditions. In this study, it was investigated to solve these problems for the supports of the various fittings for easy installation-related support that each type of intensity and shape and manufacturing method using structural analysis program(DNV Nauticus Hull 3D Beam). Namely, it would be applied to the very large crude carriers in consideration of mechanics of materials of the support equipment by providing the fact that dynamics analysis of the structural characteristics of the equipment and the support of the production installation is easy and productivity can be high standards for geometry and thereby to simplify the analysis task to design changes at the same time and to minimize the reinforcement for the supports.