• Journal of Chest Surgery
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• v.30 no.6
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• pp.553-558
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• 1997

Arterial allografts have known advantages over prosthetic vascular conduit for treatment of heart valvular disease, congenital heart disease and aortic disease. Cell viability may play a role in determining the longterm outcome of allografts. Endothelial cell is one important part in determining the allograft viability. To evaluate the viability of endothelial cells using current allograft preservation technique, porcine heart valve leaflets and arterial wall were subjected to collagenase digestion. Single endothelial cell suspension was labeled with GSA-PITC(Griffonia simplicifolia agglutininfluorescein isothiocyan te), a vascular, endothelial cell specific marker. The cell suspension was washed and incubated with Pl(Propidium iodide), which does not bind with viable cells, Endothelial cell viability was evaluated by calculating the percentage of GSA-FITC(+) and Pl(-) group using flowcytometric analysis. Allografts were treated with $4^{\circ}C$ antibiotic solo!ion for 24 hours for sterilization. After this, half of allografts were stored in $4^{\circ}C$ RPMI 1640 with HEPES buffer culture medium with 10% fetal bovine serum for 1 to 14 days(Group I). Another half of allografts were cryopreserved with a currently used technique (Group II). During the procurement and sterilization of arterial allografts, 22.8% and 24.4% of endothelial cell viability declined, respectively. In Group I, 11.9% of endothelial cell viability declined further steadily during 14 days of storage. In Group II, 13.7% of endothelial cell viability declined. These results show that largest loss of endothelial cell viability occurs during the nitial process. After 14 days of arterial allograft storage under $4^{\circ}C$ nutrient medium or cryopreservation, about 40% of endothelial cell viability is maintained. There were no differences between the endothelial cell viability from aortic valve leaflet, pulmonic valve leaflets, aortic wall and pulmonic wall.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.184-189
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• 2008

Effects of sucrose at different concentrations (0, 10, 20, and 30%, w/w) on steady and dynamic shear rheological properties of sweet potato starch (SPS) paste (5%, w/w) were investigated. The steady shear rheological properties of SPS-sucrose composites were determined from rheological parameters based on power law and Casson flow models. At 25$^{\circ}C$ all the samples showed pseudoplastic and thixoropic behavior with high yield stress. Consistence index (K), apparent viscosity (${\eta}_{a,100}$), and yield stress (${\sigma}_{oc}$) values of SPS-sucrose composites decreased with increasing sucrose concentration from 10% to 30%. The decrease of swelling power was observed at higher sucrose concentration (>20%) and the low swelling power yielded a lower K, ${\eta}_{a,100}$, and ${\sigma}_{oc}$ values. In temperature range of 25-70$^{\circ}C$, Arrhenius equation adequately assessed variation with temperature. Oscillatory test data showed weak gel-like behavior. Magnitudes of storage (G') and loss (G") moduli increased with an increase in sucrose concentration and frequency. The SPS-sucrose composite at 30% concentration closely followed the Cox-Merz superposition rule.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.457-470
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• 2019

This study aims to present the characteristics of marine physics, water quality, and sediment quality around offshore wind farm near the Gochang and Buan sea areas through the analysis of monitoring data. The relationships between suspended solid and wave height as well as suspended solid and flow velocity were analyzed. We found that Correlation Coefficient values of 0.61~0.69 between wave height and suspended solid, and suspended solid concentration reaches 75 mg/L or higher when wave height of more than 1m occurred in the spring (1 month). The water quality index (WQI) was used to identify the status of the water quality in the study area. Most of the measured points were rated first grade (very good). The variation of chlorophyll-a was relatively hight compared to the other criteria, indicating that it is a major factor affecting the quality index. In the sediment column, all heavy metals were detected below the Threshold Effects Level(TEL), and ignition loss and grain size show a positive correlation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.61-68
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• 2020

In this study, the international standard ISO TS 16774 Part 3 Test Method for Water (wash out) Resistance and KS F 4935 ｢Sealant Injection type for water leakage maintenance of adhesive flexible rubber asphalt series｣, which are standardized as a quality control method of injection type repair materials used for water leakage cracks in underground concrete structures, are currently used in Korea. As a result, considering the performance criteria of "mass change rate -0.1%" stipulated in KS F 4935, the remaining 13 types repair materials, excluding RG-2 of synthetic rubber and UG-1 of urethane, need to be reviewed for stabilization of the loss resistance due to the flow of ground water. The results of this study are determined to be available as a basic indicator for the selection of repair materials used for cracks in concrete structures. In addition, it is expected that the results of this study can be utilized as reference data that can be reflected in the improvement of the quality of repair materials that will be researched and developed later.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.561-577
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• 2021

The compacted bentonite buffer in a geological repository for high-level radioactive waste disposal is saturated due to groundwater inflow. Saturation of the bentonite buffer results in bentonite swelling and bentonite penetration into the rock discontinuities present around the disposal hole. The penetrated bentonite is exposed to groundwater flow and can be eroded out of the repository, resulting in bentonite mass loss which can affect the physical integrity of the engineered barrier system. Hence, the evaluation of buffer-rock interactions and coupled behavior due to groundwater inflow and bentonite penetration is necessary to ensure long-term disposal safety. In this study, the effects of the bentonite penetration and swelling on the physical properties of jointed rock mass were evaluated using the quasi-static resonant column test. Jointed rock specimens with bentonite penetration were manufactured using Gyeongju bentonite and hollow cylindrical granite rock discs obtained from the KAERI underground research tunnel. The effects of vertical stress and saturation were assessed using the P-wave and S-wave velocities for intact rock, jointed rock and jointed rock with bentonite penetration specimens. The joint normal and joint shear stiffnesses of each joint condition were inferred from the wave velocity results assuming an equivalent continuum. The joint normal and joint shear stiffnesses obtained from this study can be used as input factors for future numerical analysis on the performance evaluation of geological waste disposal considering rock discontinuities.

• Journal of Korean Society of Disaster and Security
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• v.14 no.4
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• pp.17-27
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• 2021

Streamflow prediction is a very vital disaster mitigation approach for effective flood management and water resources planning. Lately, torrential rainfall caused by climate change has been reported to have increased globally, thereby causing enormous infrastructural loss, properties and lives. This study evaluates the contribution of rainfall to streamflow prediction in normal and peak rainfall scenarios, typical of the recent flood at Piney Resort in Vernon, Hickman County, Tennessee, United States. Daily streamflow, water level, and rainfall data for 20 years (2000-2019) from two USGS gage stations (03602500 upstream and 03599500 downstream) of the Piney River watershed were obtained, preprocesssed and fitted with Long short term memory (LSTM) model. Tensorflow and Keras machine learning frameworks were used with Python to predict streamflow values with a sequence size of 14 days, to determine whether the model could have predicted the flooding event in August 21, 2021. Model skill analysis showed that LSTM model with full data (water level, streamflow and rainfall) performed better than the Naive Model except some rainfall models, indicating that only rainfall is insufficient for streamflow prediction. The final LSTM model recorded optimal NSE and RMSE values of 0.68 and 13.84 m³/s and predicted peak flow with the lowest prediction error of 11.6%, indicating that the final model could have predicted the flood on August 24, 2021 given a peak rainfall scenario. Adequate knowledge of rainfall patterns will guide hydrologists and disaster prevention managers in designing efficient early warning systems and policies aimed at mitigating flood risks.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.345-356
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• 2022

A severe flooding occured at a small urban catchment in Daejeon-si South Korea on July 30, 2020 causing significant loss of property (inundated 78 vehicles and two apartments) and life (one casualty and 56 victims). In this study, a retrospective analysis of the inundation event was implemented using a physically-based urban flood model, H12 with high-resolution data. H12 is an integrated 1-dimensional sewer network and 2-dimensional surface flow model supported by hybrid parallel techniques to efficiently deal with high-resolution data. In addition, we evaluated the impact of the flooding barriers which were installed after the flood disaster. As a result, it was found that the inundation was affected by a combination of multiple components including the shape of the basin, the low terrain of the inundation area located in the downstream part of the basin, and lack of pipe capacity to drain discharge from the upstream during heavy rain. The impact of the flooding barriers was analyzed by modeling with and without barriers on the high-resolution terrain input data. It was evaluated that the flood barriers effectively lower the water depth in the apartment complex. This study demonstrates capability of high-resolution physically-based urban modeling to quantitatively assess the past inundation event and the impact of the reduction measures.

• Journal of the Korea Society of Computer and Information
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• v.27 no.2
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• pp.171-177
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• 2022

In this paper, we propose a service method that can provide insight into multi-source agricultural data, way to cluster environmental factor which supports data analysis according to time flow, and curate crop environmental factors. The proposed curation service consists of four steps: collection, preprocessing, storage, and analysis. First, in the collection step, the service system collects and organizes multi-source agricultural data by using an OpenAPI-based web crawler. Second, in the preprocessing step, the system performs data smoothing to reduce the data measurement errors. Here, we adopt the smoothing method for each type of facility in consideration of the error rate according to facility characteristics such as greenhouses and open fields. Third, in the storage step, an agricultural data integration schema and Hadoop HDFS-based storage structure are proposed for large-scale agricultural data. Finally, in the analysis step, the service system performs DTW-based time series classification in consideration of the characteristics of agricultural digital data. Through the DTW-based classification, the accuracy of prediction results is improved by reflecting the characteristics of time series data without any loss. As a future work, we plan to implement the proposed service method and apply it to the smart farm greenhouse for testing and verification.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.107-117
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• 2019

This paper establishes and propagates the value of the play through the study of the transition process of the yesan play from 1920 to the present, presents an alternative through the unique theatricality of the region and aims to activate it. The theater divided the theater into Yecheon, Chungnam Theater Festival, and Youth Theater Festival, which are currently active, and focused on Yedang International Performing Arts Festival, which is the only one in Yesan. The details of the performance due to the loss of data were not specified as much as possible, but the contents of the yesan play before 1990 were reviewed using the eupji and Myeonji. It also starts with a lack of diversity in plays in the developing direction of Yesan. Children's plays should be dismissed for simple commercial purposes, or the value of traditional Korean plays should be compared to Western ones, to promote the development of local plays through the natural characteristics and the basis of traditional culture, and to sustain the continuity of extreme economic performance and performances through the development of repertoires. Infrastructure deployment can be cited. The in flow of specialized actors and the use of art administrators creates a stable theater environment and activates the reeducation of local actors to promote theatrical imagination. It is also an urgent task to develop a new theatrical form by introducing experimental theatrical methods of young artists in the overseas performance business of theater troupe Yechon. Finally, Yedang International Performing Arts Festival should be characterized and differentiated from other festivals.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.518-526
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• 2022

The extension of life expectancy due to modernization means an extension of the benefit time for elderly care and disease. However, compared to the increase in the elderly, the attitude of children toward parental responsibility is gradually weakening. These social phenomena bring alienation, hopelessness, and stress to life in old age, and the resulting sense of helplessness leads to suicidal thoughts or intentional death (suicide), becoming a social problem. The intentional death (suicide) of the elderly is a social phenomenon that often occurs around them, and the reality can be seen through the movie. In this study, the main character 'Soyoung' in the movie 'The Woman Who Kills' and the surrounding characters 'Song Old Man', 'Jongsu', and 'Jaewoo' in conversations with the elderly problem and death factors were analyzed in the Matrix. ), and then applied to the 'flow chart of problems in the elderly due to modernization' compiled by Byeong-Woo Lim (2019), to explore the factors of intentional death (suicide). As a result of the analysis, the four elderly were exposed to problems of the elderly such as disease, alienation and loneliness, poverty, and loss. (Suicide) was analyzed.