• Korean Journal of Environmental Agriculture
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• v.23 no.3
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• pp.123-127
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• 2004

In many organisms, trehalose has been Down as an energy source and a protectant against various environmental stresses such as desiccation, freezing, heat and osmotic pressure. Previously, we have isolated and characterized the genes encoding trehalose-6-phosphate synthase (ZrTPS1) and trehalose-6-phosphate phosphatase (ZrTPS2) from one of the most osmotolerant yeasts, Zygosaccharomyces rouxii. We have also generated transgenic plants by co-introduction of ZrTPS2 and ZrTPS2 into potato plant (ZrTPS2-2A-ZrTPS1 plant) in an attempt to metabolically engineer trehalose in the transgenic plant using the foot-and-mouth disease virus(FMDV) 2A system and to generate drought resistant crop plants. In this research, we assayed previously generated the ZrTPS2-2A-ZrTPS1 plant biofunctionally by drought treatment, and measured the amount of trehalose in the ZrTPS2-2A-ZrTPS1 transgenic plants. The ZrTPS2-2A-ZrTPS1 transgenic plant showed strong drought resistance in spite of little or no accumulation of transgenic in he transgenic plant compared with control plant.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.133-140
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• 2017

The performance prediction software developed in this paper is a process analysis tool that enables one to foretell the behavior of processes when certain conditions of operation are altered. The immediate objective of this research is to predict the process characteristics of combined heat and power plant under varying operating conditions. A cogeneration virtual power plant that mimics the mechanical performance of the actual plant was constructed and the performance of the power plant was predicted in the following varying atmospheric conditions: temperature, pressure and humidity. This resulted in a positive outcome where the performance of the power plant under changing conditions were correctly predicted as well as the calorific value of low calorific gas fuel such as shale gas and PNG. The performance prediction tool can detect the operation characteristics of the power plant through the performance index analysis and thus propose the operation method taking into consideration the changes in environmental conditions.

• Journal of Power System Engineering
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• v.9 no.1
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• pp.5-13
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• 2005

Acoustic emission(AE) is defined as the transient elastic waves thar are generated by the rapid release of energy. The advantage of AE is that very early crack growth can be detected well before a highly stressed component may fail. At present, an exact diagnosis is the most reliable means for determining the soundness of structures during power plant operations. AE monitoring has been applied successfully in power plants to determine mechanical problems, pressure vessel integrity and external valves leaks, vacuum leaks, the onset of cavitation in pumps and valves, the presence of flow(or no flow) in piping and heat exchange equipment, etc. Acoustic emission(AE) technology has recently strengthened its application base, and practitioners' understanding of the technique's fundamentals. This paper introduces the methods of a survey and assessment on AE monitoring applications in nuclear, fossil and hydraulic power plant. The main objective of this paper was to obtain information on various applications of AE technology in power plant.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.1
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• pp.25-33
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• 2019

In the plant industry, the share of equipment accounts for 45 ~ 75%, which is very high. It is a traditional plant centered on processes and reactions like petroleum and chemical plants. Renewable energy generation plants such as wind power generation and solar power generation are equipment-centric plants. Equipment-centric plants are very important not only in the EPC phase but also in the operation and management phase. The procurement of equipment for plant operation and management can be divided into make and buy. Make is a method of producing equipment itself, and buy is a method of procuring equipment from the outside. The procurement method of the equipment directly affects the plant operation and management cost. In this study, the decision making of equipment procurement method for plant operation and management is defined as 4 phase. Each phase is selection of procurement decision-making objects, technology strategy perspective, finance perspective, and production perspective. In detail, we defined selection process of procurement decision-making objects and technology strategy perspective process. We will contribute to the enhancement of the competitiveness of the plant operation and management area by carrying out researches on the process and application examples of financial and production perspectives in the future.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.237-268
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• 2021

As variable renewable sources rapidly increase due to the Energy Transition plan, integration cost of renewable sources to the power system is rising sharply. The increase in variable renewable energy reduces the capacity factor of existing traditional power capacity, and this undermines the efficiency of the overall power supply, and demand resources are drawing attention as a solution. In this study, we analyzed how much electric vehicle demand resouces, which has great potential among other demand resources, can reduce power supply costs if it is used as a flexible resource for renewable generation. As a methodology, a stochastic form of power system optimization model that can effectively reflect the volatile characteristics of renewable generation is used to analyze the cost induced by renewable energy and the benefits offered by electric vehicle demand resources. The result shows that virtual power plant-based direct control method has higher benefits than the time-of-use tariff, and the higher the proportion of renewable energy is in the power system, the higher the benefits of electric vehicle demand resources are. The net benefit after considering commission fee for aggregators and battery wear-and-tear costs was estimated as 67% to 85% of monthly average fuel cost under virtual power plant with V2G capability, and this shows that a sufficient incentive for market participation can be offered when a rate system is applied in which these net benefits of demand resources are effectively distributed to consumers.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.1
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• pp.47-56
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• 2015

Energy consumption in buildings is currently a real problem. That is why both assessment of energy performance and effective energy management including renewable energy system are essential. Thus, this paper focuses on a case study to analyze the energy performance and cooling & heating energy saving of a large scale shopping store in Daejeon city. The reference building is simulated by using TRNSYS dynamic simulation tool to examine its annual energy consumption. For annual energy analysis of building, one year energy consumption is surveyed in the field. The related study is carried out in large scale shopping store to investigate the energy consumption and energy use trend of heating, cooling, hot water, lighting, ventilation, equipments and other. The evaluation of energy performance of the geothermal heat pump system installed in a large scale shopping store is also analyzed by TRNSYS tool. From simulation results, it evaluated that the geothermal heat pump system is effective energy savings method in large scale shopping store.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.13-29
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• 2016

In this study, we analyzed the causes of major faults in the biogas plant through the case of gas engine failure when cogenerating electricity and heat using biogas as a fuel in the actual sewage treatment plant and suggested countermeasures. Hydrogen sulfide in the biogas entering the biogas engine and water caused by intermittent malfunction of the water removal system caused intercooler corrosion in the biogas engine. In addition, the siloxane in the biogas forms a silicate compound with silicon dioxide, which causes scratches and wear of the piston surface and the inner wall of the cylinder liner. The substances attached to the combustion chamber and the exhaust system were analyzed to be combined with hydrogen sulfide and other impurities. It is believed that hydrogen sulfide was supplied to the desulfurization plant for a long period of time because of the high content of hydrogen sulfide (more than 50ppm) in the biogas and the hydrogen sulfide was introduced into the engine due to the decrease of the removal efficiency due to the breakthrough point of the activated carbon in the desulfurization plant. In addition, the hydrogen sulfide degrades the function of the activated carbon for siloxane removal of the adsorption column, which is considered to be caused by the introduction of unremoved siloxane waste into the engine, resulting in various types of engine failure. Therefore, hydrogen sulfide, siloxane, and water can be regarded as the main causes of the failure of the biogas engine. Among them, hydrogen sulfide reacts with other materials causing failure and can be regarded as a substance having a great influence on the pretreatment process. As a result, optimization of $H_2S$ removal method seems to be an essential measure for stable operation of the biogas engine.

• Journal of Radiation Protection and Research
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• v.20 no.4
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• pp.245-253
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• 1995

The effects of a simultaneous application of KCl and lime on the root uptake of $^{54}Mn,\;^{60}Co,\;^{85}Sr\;and\;^{137}Cs$ by rice, soybean, Chinese cabbage and radish were investigated through 2 years' greenhouse experiments. At their early growth stages, a mixed solution of the radionuclides was applied to the water or soil surfaces of the culture boxes filled with an acidic loamy-sandy soil for the upper 20cm and $83g/m^2$ of fertilizer KCl and $200g/m^2$ of slake lime were applied to the surfaces. Distribution of radioactivities among plant parts and change in uptake pattern with plant species were not, on the whole, significantly affected by the application. It reduced effectively soil-to-plant transfer factors of $^{85}Sr\;and\;^{137}Cs$ for rice, of all for Chinese cabbage and of $^{54}Mn,\;^{60}Co,\;and\;^{137}Cs$ for radish without their growth inhibition. In rice, $^{85}Sr$ showed the highest decrease $({\sim}60%)$ while, in Chinese cabbage and radish, $^{54}Mn$ did $({\sim}80%)$. The exprimental results can become valuable reference data to establish countermeasures against a radioactive contamination of farm-land during plant growth.

• Journal of IKEEE
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• v.25 no.2
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• pp.267-272
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• 2021

Recently, attention has been focused on renewable energy and carbon neutrality to resolve fossil energy depletion and environmental problems. In addition, high-rise urban buildings and an increase in building energy are rapidly increasing. There are many restrictions on installing solar power in urban areas. In addition, as buildings become taller, a lot of low-light environments in which shade is formed occur. Therefore, in this study, we intend to develop a power plant capable of generating electric power in an outdoor low-light environment and indoor lighting environment. The power plant in a low-light environment used a dye-sensitized solar cell. A unit cell and a 20cm×20cm module were manufactured, and the electrical characteristics of the power plant were measured using light sources of LED, halogen lamp, and 3-wavelength lamp. The photoelectric conversion efficiency of the unit cell was 17.2%, 1.28%, 19,2% for each LED, halogen lamp, and 3-wavelength lamp, and the photoelectric conversion efficiency of the 20cm×20cm module was 10.9%, 8.7%, and 11.8%, respectively. In addition, the maximum power value of the module was 13.1mW, 15.7 mW, and 14.2 mW for each light source, respectively, confirming the possibility of power generation in a low-light environment

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.2
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• pp.86-92
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• 1993

The variation of the esterase isozyme, germination rate, chemical composition and digestibility of field bean(G1ycine soja S. and Z.) were estimated. The results are as follows; 1. The banding patterns of the esterase isozyme in field bean were varied with the tissue and habitat. 2. The enzyme activity of the Est-I, Est-2, Est-3 and Est-4 in field bean showed a high value compared with the other enzyme. 3. The range of germination temperature in field bean was 10-40C and the optimum germination temperature was 25- 38^{\circ}C.$. 4. The crude protein(CP) contents was 19.9% in the whole plant, 27.8% in the leaf and 45.9% in the seed, the cellulose contents was 29.5% in the whole plant, 23.0% in the leaf and 13.8% in the seed, the neutral detergent fiber(NDF) was 62.6% in the whole plant, 47.9% in the leaf and 47.9% in the seed and the acid detergent fiber(ADF) was 44.5% in the whole plant, 28.4% in the leaf and 28.4% in the seed, respectively. 5. The digestibility of the field bean was 44.1% in the whole plant, 49.6% in the leaf and 75.1% in the seed, NDF was 26.2% in the whole plant 46.2% in the leaf, ADF was 29.0% in the whole plant, 47.7% in the leaf and 58.0% in the seed and Cellulose was 48.7% in the whole plant, 58.0% in the leaf and 70.2% in the seed, respectively. 6. Total digestible nutrients(TDN) of the field bean was 47.4% in the whole plant, 51.5% in the leaf and 70.2% in the seed, respectively. The digestible energy(DE) value was 2.1 kcal/g in the whole plant, 2.27 kcal/g in the leaf and 3.10 kcal/g in the seed and the metabolizable energy(ME) value was 1.72 kcal/g in the whole plant, 1.86 kcal/g in the leaf and 3.23 kcal/g in the seed, respectively.