• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.25-34
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• 2017

Offshore plants should be managed at a high level of safety condition. Because the offshore plant has cramped space and has difficult access when a fire occurred, a fire can be critical to the plants. LED lighting can reduce the risk of fire by its lower energy consume suitable to intrinsic safety and lower heat radiation that can reduce the possibility of ignition. Also LED has a long lifetime. Though LED luminaire has various advantages for offshore plants, an international standard for the luminaire has not provided because it is new technology. Because there is no international and domestic standard specially provided for the LED luminaire, a guideline is required for developing the LED light and for the future establishment of an international standard. This study was conducted to develop the guideline for LED luminaire for offshore plants. Firstly, relevant standards were analyzed for the guideline. Then we found that there are editorial differences between international standards and domestic standards. So the guideline was developed based on international version and the differences between the domestic and international standard were provided to let Korean developers recognize the differences.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.45-53
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• 2000

The optimum operation of domestic wastewater treatment plant can give influence on operational cost and future expansion in Korea where has 93 operational domestic wastewater treatment plants. Also, the study on optimum operation can reduce operation cost and budget of municipalities whom have responsibility of wastewater treatment plant operation. In this study, 9 domestic wastewater treatment plants which can represent 93 plants in Korea have been selected and operational data are gathered. The collected data are inputted to computer simulator based on IAWQ's Activated Sludge Model No.1 and optimum operation methods are developed. Also, the electric power for aeration which has large portion of overall operation cost are calculated based on design and operation conditions and these are compared. In this study, it was found that design wastewater characteristics are 1.6 times higher than those of daily maximum except for E plant and that estimation methods for design wastewater characteristics have to be improved. Based on computer simulation, we found there is no need to operate all aeration tanks due to weak influent overall power for aeration can be reduced to about 43% of design one.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.10
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• pp.1171-1176
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• 2009

This paper provides how to establish an integrated plan for LE (life extension) and MD (modernization) of aged hydropower plants. The methodology is developed through review of overseas/domestic LE/MD histories, investigation of the previous overseas methodologies and consideration of domestic practices. The methodology includes reviews of the various factors such as condition, operation and maintenance history, up-to-date technology, and economic benefit. In order to establish the life extension/modernization plan, the methodology is applied to the domestic aged hydropower plants. Finally, priority rankings and draft practice plans for LE/MD are derived.

• Korean Journal of Pharmacognosy
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• v.28 no.1
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• pp.15-20
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• 1997

This study was carried out to investigate the antioxidative activities of domestic plants grown in the area of Kangwon-do province. Through the examination of methanol extracts from 15 plants for radical scavenging effects using DPPH method, the extracts from Pinus densiflora Sieb. et Zucc. And Euphorbia humifusa Willd. Showed strong antioxidative activity. Because of its highest antioxidative activity among 15 domestic plants, radical scavenging effects of four different extract compartments from leaves of P.densiflora, n-Hexane, EtOAc, BuOH and $H_2O$ extracts. Were examined by DPPH method. Antioxidative activities of EtOAc and BuOH extracts were similar or even higher than that of natural (tocopherol) or synthetic antioBfdants (BHA) , suggesting that major fraction for the antioxidative activity of P. densiflora was the EtOAc and BuOH extract compartments.

• Fire Science and Engineering
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• v.28 no.5
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• pp.14-22
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• 2014

Hydrocarbon fires and explosions in petrochemical plants have occurred repeatedly every year. But domestic law of fire protection system is insufficient for the worst case scenario. In this study, we analyzed domestic and foreign standards of fire protection system in petrochemical plants and surveyed firefighting equipment of 32 petrochemical plants in ulsan petrochemical complex. Finally, it is necessary to design fire water supply based on the worst case scenario in petrochemical plants and firefighting equipment such as fixed water spray system, elevated monitor nozzle, water curtain, large amount foam monitor system should be installed for the worst case scenario in petrochemical plants.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.589-605
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• 2012

This study was conducted to identify allelopathic effect of Ganghwa domestic Artemisia spp., named Sajabalssuk and Ssajuarissuk, for various receptor plants including clover (Trifolium repens L.), alfalfa (Medicago sativa L.), lawn grass (Zoysia japonica Steud.), dandelion (Taraxacum platycarpum Dahlst.), and dahurianpatrinia (Patrinia scabiosaefolia Fisch. ex Trevir). Receptor plants were treated with the aqueous and essential oil extract of Artemisia plants. In consequence, their allelopathic effects were evaluated by measuring seed germination rates, seedling growth, and dry weights of the receptor plants. The seed germination and seedling growth of the receptor plants were inhibited by all treatments of both aqueous and essential oil extracts of the Artemisia plants, and, in addition, the inhibitory effects were increased according to the higher concentration. Among the donor plants, A. $sp.^*III$ showed most effective allelopathic effect. Comparing the alleopathic effect among the receptor plants, seed germination was most inhibited in lawn grass while inhibitory effect of seedling growth was comparatively higher in dandelion. Although inhibitory effects were comparatively lower, the allelopathic effects of Artemisia plants were identified in clover and alfalfa since the seedling growth of these plants were inhibited more than 70%. Thus, in result, Ganghwa domestic Artemisia spp. could be possibly used for weed control since natural products of the plants showed inhibitory effects on seed germination and seedling growth of various receptor plants.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.8
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• pp.1172-1180
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• 2017

This study analyzed competition in peak load plants between CCGT and GT instead of competition between base and peak load plants like in previous studies. In common overseas power markets, CCGT and GT claim certain market shares as peak load plants with the latter boasting a high utilization rate as reserve plants. In South Korea, however, there has been no introduction of GT in the market that opened in 2001 with no analysis cases of GT's economy as a peak load plant. The current power market of South Korea is run on the cost-based pool, which allows for no price spikes. Since the capacity payment criteria for compensations for missing money are set based on GT generators, the power market uses GT generators as marginal plants. The purposes of this study were to analyze the competitive edge of GT generators as peak load plants in the domestic power market of South Korea and identify the causes of GT's failure in market entry, thus assessing the adequacy of market signals in the domestic power market.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.91-91
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• 2022

Popcorn grains are consumed around 10,000 tons per year, in South Korea. It is consumed in amusement parks, movie theaters and snacks. The size of the popcorn processed market in Korea is estimated to be 3.6 billon won per year. So, the popcorn grain market has good prospects. On the other hand, domestic grain is at the level of 1 %, which is less domestic production than the size of the market. Maize Research Institute has developed domestic varieties in order to increase the use of domestically produced grains. The Oyrunpopcorn variety which was commonly distributed is a preferred cultivar because it has a good popping rate compared to imported grains. In addition, 'G-Popcom', 'Oyrun #2' and 'Kichan Popcorn' were developed, which diversified the choice of the farmers. Yield per unit area is important to improve farmers' income. At present, domestic grain production is traded at 5,000 won/kg, so if the yield improves, a high farmer^ income is expected. Therefore, this study compared the growth characteristics and yield according to the appropriate sowing time and plant density to improve the yield of domestically grown popcorn. We used 'Oryunpopcorn', for this research. Agronomic characteristics were compared by sowing times April 23, May 22 and June 22. The 100 seeds weight were 15.9g, 17.7g and 15.0g, respectively. Kernel weight planted in May 22 is the highest value. Yield per 10a were 414kg, 434kg and 296kg, respectively. It shows the yield planted in May 22 was higher than other trials. Therefore, the sowing time to increase the kernel weight and yield is appropriate for planting in mid-May. The number of plants in planting density trial was 5,700 plants, 4,700 plants and 4,000 plants in 10a area. Plant height at each trial were 221 cm, 214cm and 218cm, respectively. It was the highest height in 5,700 plants trials. The 100 kernel weight were 14.8g, 15.9g and 16.5g, respectively. Low planting density trial indicated high kernel weight. Yield per 10a was 415kg, 357kg and 314kg, respectively. It was higher at high density trial than other experimental plots. Therefore, appropriate sowing time was in mid-May and planting density was 5,700 plants/10a in order to increase the yield of popcorn in South Korea. This study will be useful for farmer's income to use the domestic cultivars.

• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.370-378
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• 2019

In the recent years, various studies have presented stable and economic methods for increased regulations and compliance in sewage treatment plants. In some sewage treatment plants, the effluent concentration exceeded the regulations, or the effluent concentration was manipulated. This indicates that the process is currently inefficient to operate and control sewage treatment plants. The operation and control method of sewage treatment plant is mathematically dealing with a physical and chemical mechanism for the anticipated situation during operation. In addition, there are some limitations, such as situations that are different from the actual sewage treatment plant. Therefore, it is necessary to find a more stable and economical way to enhance the operational and control method. AI (Artificial Intelligence) technology is selected among various methods. There are very few cases of applying and utilizing AI technology in domestic sewage treatment plants. In addition, it failed to define specific definitions of applying AI technologies. The purpose of this study is to present the application of AI technology to domestic sewage treatment plants by comparing and analyzing various cases. This study presented the AI technology algorithm system, verification method, data collection, energy and operating costs as methods of applying AI technology.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.640-646
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• 2018

Biomass-fired power plants produce electricity and heat by burning biomass in a boiler. However, one of the most serious problems faced by these plants is severe corrosion. In biomass boilers, corrosion comes from burnt fuels containing alkali, chlorine, and other corrosive substances, causing boiler tube failures, leakages, and shorter lifetimes. To mitigate the problem, various approaches implying the use of additives have been proposed; for example, ammonium sulfate is added to convert the alkali chlorides (mainly KCl) into the less corrosive alkali sulfates. Among these approaches, the high temperature corrosion prevention technology based on ammonium sulfate has few power plants being applied to domestic power plants. This study presents the results obtained during the co-combustion of wood chips and waste in a circulating fluidized bed boiler. The aim was to investigate the characteristics of pollution load in domestic biomass power plants with ammonium sulfate injection. By injecting the ammonium sulfate, the KCl content decreased from 68.9 to 5 ppm and the NOx were reduced by 18.5 ppm, but $SO_2$ and HCl were increased by 93.3 and 68 ppm, respectively.