• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.63-81
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• 2021

In this study, we investigated the tide-induced flow patterns near the ocean outfall of the Jeju and Bomok Wastewater Treatment Plants (WTP) in Jeju Island by using measurements of Acoustic Doppler Current Meter (ADCP) and a numerical experiment with inserting passive tracer into a regional ocean model. In late spring of 2018, the ADCP measurements showed that tidal currents dominate the flow patterns as compared to the non-tidal components in the outfall regions. According to harmonic analysis, the dominant type of tides is mixed of diurnal and semi-diurnal but predominantly semidiurnal, showing stronger oscillations in the Jeju WTP than those in the Bomok WTP. The tidal currents oscillate parallel to the isobath in both regions, but the rotating direction is different each other: an anti-clockwise direction in the Jeju WTP and a clockwise in the Bomok WTP. Of particular interest is the finding that the residual current mainly flows toward the coastline across the isobath, especially at the outfall of the Bomok WTP. Our model successfully captures the features of tidal currents observed near the outfall in both regions and indicates possibly high persistent pollutant accumulation along the coasts of Bomok.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.203-215
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• 2022

The study is to investigate research trends and knowledge structures in the Smart Farm field. To achieve the research purpose, keywords and the relationship among keywords were analyzed targeting 104 Korean academic journals related to the Smart Farm in KCI(Korea Citation Index), and topics were analyzed using the LDA Topic Modeling technique. As a result of the analysis, the main keywords in the Korean Smart Farm-related research field were 'environment', 'system', 'use', 'technology', 'cultivation', etc. The results of Degree, Betweenness, and Eigenvector Centrality were presented. There were 7 topics, such as 'Introduction analysis of Smart Farm', 'Eco-friendly Smart Farm and economic efficiency of Smart Farm', 'Smart Farm platform design', 'Smart Farm production optimization', 'Smart Farm ecosystem', 'Smart Farm system implementation', and 'Government policy for Smart Farm' in the results of Topic Modeling. This study will be expected to serve as basic data for policy development necessary to advance Korean Smart Farm research in the future by examining research trends related to Korean Smart Farm.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.835-842
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• 2022

This study is aimed to evaluate the effects of a synthetic MR technique in reducing metal artifacts. In the experiment, the in-plane and through-plane images were acquired by applying a synthetic MR technique and a high-speed spin echo technique to a phantom manufactured with screw for spinal surgery. The area of the metal artifact was compared. The metal artifacts were measured by dividing the signal-loss and the signal pile-up areas, and the area of the final artifact was calculated through the sum of the two. As a result, the metal artifacts were relatively reduced when the synthetic MR techniques were applied to both in-plane and through-plane. Comparing by sequence, the in-plane T1 images decreased by 23.45%, T2 images by 20.85%, PD images by 19.67%, and FLAIR images by 22.12%. Also, in the case of the through-plane, the T1 image decreased by 62.95%, the T2 image decreased by 73.93%, the PD image decreased by 74.68%, and the FLAIR image decreased by 66.43%. The cause of this result is that when the synthetic MR technique is applied, the distortion is due to the signal pile-up and does not occur and the size of the entire metal artifact is reduced. Therefore, synthetic MR technique can very effectively reduce metal artifacts, which can help to increase the diagnostic value of images.

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.129-142
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• 2022

This study evaluates a program developed for a high school-university linked class. The program combines maker education and smart clothing technology, which has great potential. First, in the preparation stage, the dyeing design course incorporates the contents of previous studies on smart clothing and maker education. Second, in the development stage, a program was developed to make emotional eco-bags by applying the transfer dyeing technique using transfer paper for inkjet printers and smart clothing technology using conductivity thread and LED bulbs. Third, in the implementation stage, the class was offered to 17 high school students who want to major in clothing and textiles. Lastly, the class was evaluated. The program had a 4.95 satisfaction level as measures on a five-point scale. Furthermore, this paper suggested an advanced program with Lilypad Arduino. In conclusion, through this study, it was confirmed that the emotional eco-bag development program applied with conductive yarn and transfer dye could more easily produce smart clothing technology, thereby expanding the thinking of high school students regarding the clothing major.

• Journal of the Korean Institute of Gas
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• v.26 no.5
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• pp.1-9
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• 2022

Selection of a suitable artificial lift is important in terms of efficient operation and economics for oil production. In general, process of well design includes the selection of artificial lift, but the oil recovery could be enhanced by use of hybrid system combined with two types of artificial lift method according to reservoir condition for oil production. Electric submersible pump (ESP), as a presentative artificial lift method, is a manner for supplying the pressure in the lower part of oil well by using of a multi-stage centrifugal pump with an electric energy. However, there is a disadvantage that has a limit to the application period because of mechanical defection on ESP. Accordingly, it is possible to reduce the shutdown time of production well by applying the ESP/Gas lift hybrid system, which is to switch to a gas lift when an ESP is defective. This study describes the effect of ESP/gas lift hybrid system compared with ESP method for a onshore horizontal well locating in the of Permian basin, USA. As a result of study, ESP/gas lift hybrid system could make more effective productivity than ESP method. Also, we quantitatively predicted how much economic benefit would be obtained when the hybrid system was applied in the production well.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.155-160
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• 2022

The debate of South-North transboundary rivers must be expanded from the existing cooperation in water resources towards cooperation within ecosystem conservation. Regarding the Han and Imjin rivers confluence water system, the nature of the estuarine ecosystem must be conserved considering the aspect of climate change. Furthermore, the agenda of maintaining continuous inter-Korean communication and cooperation should focus on ecosystem conservation, including conserving migratory species that inhabit both Koreas. Notably, within the Han and Imjin rivers confluence, transboundary rivers are abundant legally protected species such as Grus vipio, Anser fabalis, Anser cygnoides, Platalea minor, Lutra lutra, Prionailurus bengalensis which suggests a strong need for a debate regarding habitat conservation. This study analyzed the ecosystem conditions and environmental aspects within the confluence of Han and Imjin rivers. In addition, this study provided step wise approach of ecosystem conservation that consider conditions for potential direct inter-Korean cooperation. The inter-Korean cooperation mentioned in this study will be developed into legitimate cooperation once the results from monitoring the ecosystem of transboundary rivers, awareness raising are exchanged.

• Journal of Wetlands Research
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• v.25 no.3
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• pp.213-219
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• 2023

The wetland ecosystem has a key role in climate change and can capture and store carbon long-term as blue carbon. Currently, the Republic of Korea and People's Republic of China are preparing for the UNESCO World Natural Heritage Phase II inscription, and cross-border cooperation among the two Koreas and the People's Republic of China is expected in term of the coastal wetland in the Yellow Sea region. However, there is a lack of research on the importance of coastal wetland in the Yellow Sea region for migratory bird habitats, roosting sites, feeding grounds, and stop-over sites. Thus, this study focused on the coastal wetland of the Yellow Sea region, including the southwestern coastal wetlands in the Republic of Korea, the Yancheng National Nature Reserve in the People's Republic of China designated as UNESCO World Natural Heritage, and the Mundok Migratory Bird Reserve in the Democratic People's Republic of Korea, which is listed on the Tentative List. The cooperation for ecosystem conservation between the two Koreas and China was analyzed. The importance of coastal wetlands in the Yellow Sea region as habitats for migratory birds, roosting sites, feeding grounds, and stop-over sites, significant characteristics of Yellow Sea coastal wetlands, and conditions for cooperation among three countries, were analyzed. The direction of ecosystem conservation cooperation for coastal wetlands in the Yellow Sea region in this study will be developed into Pan-Yellow Sea conservation.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.173-183
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• 2011

Gabensis village is one of the biggest village In the Wampar Local Level Government area within the Huon Gulf District of Morobe Province with a population of around 3,000. The major staple food is banana which is well complemented by minor staples yam, cassava, Singapore/Chinese taro and sweet potato. Apart from gardening for own consumption, the villagers engage in selling of vegetables, garden staples, cocoa beans, coconuts, timber, chicken, fish and pig meat to supplement their livelihood. Livestock like pigs and chickens are also kept for meat and for commercial purpose. Bettlenut which was once one of the main cash crops has now been overtaken by cocoa due to a disease that had attacked almost the entire bettlenut tree population in the area. Even though the Wau-Bulolo highway cuts through the village and all have access to transport infrastructure, the majority of the population still encounter problems in communication due to poor telecommunication coverage. On average most people earn not more than K50 per week due to constrains in production and marketing among others. Gabensis village has the potential to develop a tourism industry given its natural attraction of Lake Wanam. Beside there is also the natural eel farming and the fish pond at the nearby Potsie village. These natural attractions pose huge tourism potential for the community. As part of government services delivery and development, education and health issues is very much important in the community however there is lack of infrastructural development and poor service delivery especially in the area of health. However, the responsibility is on the community to organize themselves to realize that potential. A well developed agro-ecotourism investments would have positive spillover effects to the community thus contributing towards improving the livelihoods of the many farming families.

• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.35-46
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• 2011

The effects of organic calcium agent(ECa) tree-spray on the mineral nutrition concentration of petiole and fruit skin and quality in grapevines were studied. The calcium concentration of petiole and fruit skin at harvest in 'Campbell Early' by tree-spray after flowering 14days of calcium agent were increased significantly in calcium chloride 0.4%, ECa 250X and MCa 500X compared to control. The calcium concentration of petiole and fruit skin at harvest by ECa tree-spray after 7 days and 14 days flowering were increased significantly compared to control and 21 days after flowering treatment. Also, The calcium concentration of petiole and fruit skin at harvest by tree-spray of ECa 250X and 125X after flowering were increased significantly compared to control and 500X treatment. Fruit quality, fruit cluster weight, cracking fruit and Bitter rot occurrence by ECa tree-spray of treatment time and concentration different showed no difference between control. Phytotoxicity by tree-spray of ECa concentration different not occur to leaf and fruit.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.621-628
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• 2022

The most realistic way to reduce noise outside the building, such as road traffic noise and aircraft noise, is to strengthen the sound insulation performance at the sound collecting points such as balconies, windows, and exterior walls of each building. However, in light of the reality that shading devices outside buildings are not yet widely used, there are not many studies on sound insulation performance improvement using external windows and window devices such as louvers and blinds. In particular, external blinds can not only block the inflow of strong sunlight in the morning and evening from the outside of the building, but also target the sound insulation effect that blocks the peak noise that occurs during commuting hours. In this study, a study was conducted to improve sound insulation performance against external noise by using an external electric blind (EEB), which is one of the most efficient window and door external shading devices. Various sound insulation performance tests were conducted while changing the configuration of external electric blinds developed for light blocking purposes. Through this, it was verified that an additional sound insulation performance of 6 dB can be obtained by installing an external electric blind compared to the reduction performance of general windows.