• Journal of Life Science
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• v.31 no.8
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• pp.745-754
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• 2021

Deterioration of the immune function weakens the body's resistance to various infections, leading to a series of diseases. Immunomodulatory biomaterials have been used to reduce the side effects of immunosuppressants or to enhance immunity. Agarwood is the aromatic resinous portion of Aquilaria trees that has been traditionally used as a medicinal herb for the treatment of various diseases. Although previous studies have shown that agarwood can improve the body's immunity, evidence for this claim is still lacking. In this study, the immune-enhancing effects of the agarwood methanol extracts of Aquilaria malaccensis Lamk were evaluated in a RAW 264.7 macrophage model. Based on the results, the agarwood extracts markedly enhanced phagocytosis in the absence of cytotoxicity. The agarwood extract-treated RAW 264.7 cells exhibited the typical morphology of activated macrophages, which are spindle-shaped with elongated filopodia. Agarwood extract also significantly increased the production of nitric oxide (NO), which is associated with the increased expression of inducible NO synthase. Moreover, the secretion and expression levels of cytokines, such as tumor necrosis factor-α and interleukin (IL)-1β and IL-6, were increased by agarwood treatment. Notably, these are also associated with a mitogen-activated protein kinase signaling pathway. Taken together, our findings provide scientific evidence that agarwood has potential immune-enhancing effects in vitro.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.10-21
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• 2021

This study analyzed how external variables, such as the supply policy of shared bicycles and the spread of infectious diseases, affect the demand for shared bicycle use in the COVID-19 era. In addition, this paper presents a methodology for more accurate predictions. The Seasonal Auto-Regulatory Integrated Moving Average with Exogenous stressors methodology was applied to capture the effects of exogenous variables on existing time series models. The exogenous variables that affected the future demand for shared bicycles, such as COVID-19 and the supply of public bicycles, were statistically significant. As a result, from the supply volume and COVID-19 outbreak according to the scenario, it was estimated that approximately 46,000 shared bicycles would be supplied by 2022, and the COVID-19 cases would continue to be at the current level. In addition, approximately 32 million and 45 million units per year will be needed in 2021 and 2024, respectively.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.61-72
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• 2018

In this study, applicability of the decentralized water supply system were investigated by the high flux evaluation using ceramic membrane with combined pretreatment process. A) filtration process increased the transmembrane pressure of 1.4 kPa and 89.5 kPa on 2 and $5m^3/m^2{\cdot}d$ of filtration flux, respectively, the physical backwashing recovery rate were less than 28.6%. The (B) Coag./Floc. - Sedi. combined process with 4 mg / L of A-PAC showed that the transmembrane pressure increased to within 6 kPa, the physical backwashing recovery rate was over 37.9 % higher than (A) Filtration process. (C) Coag./Floc. combined process showed an increase of transmembrane pressure compared with (B) Coag./Floc. - Sedi. combined process, physical backwashing recovery rate was over 84%. As a result of the membrane fouling analysis using the resistance in series model, the combined pretreatment process showed that the cake resistance (Rc) was more than 92% at membrane filtration flux of $2m^3/m^2{\cdot}d$. In the (C) Coag./Floc. combined process, cake resistance(Rc) was over 86% on high flux conditions. The coagulation floc contained in influent was removed by the membrane, and the cake layer formed with the removed floc was identified as reversible fouling resistance which could be recovered by physical backwashing. The decentralized water supply system, which has the limitation of site area and installation space, is considered to could be operation of high flux of ceramic membrane by applying (C) Coag./Floc. combined process without sedimentation process.

• The Journal of Korean Philosophical History
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• no.32
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• pp.371-394
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• 2011

Buddhism have affected Korea traditional education very much. Sam Guk Yu Sa is a book which includes the public disposition grounded on world view of Buddhism. In the wide scope, the public disposition relates to their cultivating education. This paper reviewed cultivating education grounded on John Dewey "experience-learning" model about the Buddhistic public disposition appearing in Sam Guk Yu Sa. "Meaning-experience" as "adult-becoming" appearing in Sam Guk Yu Sa shows a strong characteristic of cultivating education when we see on a creative horizon in the Buddhistic world. Dewey-Deleuze's cultivating education which modernizes the theory of John Dewey meets at the place of the public disposition and three fables of Sam Guk Yu Sa grounded on the Buddhistic world. This could open possibility to interpret the cultivating theory of Korea traditional thought and western educational theory with interdigitation. Fables of Sam Guk Yu Sa dealt with growth and maturity of the public from Buddhist monk to folk wishes to achieve Bulgukto(佛國土; the land with Buddha) through the process of cultivating education which leads to "impulse-observation-knowledge-determination." In these series of process for "adult-becoming," life itself possesses characteristic of cultivating theory. In this respect, fables of Sam Guk Yu Sa shows Korea traditional cultivating theory and can be a role of a discourse book for cultivating educational theory which could relate to western educational theory.

• Korean Journal of Metals and Materials
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• v.49 no.11
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• pp.882-892
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• 2011

The influence of rhenium (Re) and ruthenium (Ru) addition on the solidification and solute redistribution behaviors in advanced experimental Ni-base superalloys has been investigated. A series of model alloys with different levels of Re and Ru were designed based on the composition of Ni-6Al-8Ta and were prepared by vacuum arc melting of pure metallic elements. In order to identify the influence of Re and Ru addition on the thermo-physical properties, differential scanning calorimetry analyses were carried out. The results showed that Re addition marginally increases the liquidus temperature of the alloy. However, the ${\gamma}^{\prime}$ solvus was significantly increased at a rate of $8.2^{\circ}C/wt.%$ by the addition of Re. Ru addition, on the other hand, displayed a much weaker effect on the thermo-physical properties or even no effect at all. The microsegregation behavior of solute elements was also quantitatively estimated by an electron probe microanalysis on a sample quenched during directional solidification of primary ${\gamma}$ with the planar solid/liquid interface. It was found that increasing the Re content gradually increases the microsegregation tendency of Re into the dendritic core and ${\gamma}^{\prime}$ forming elements, such as Al and Ta, into the interdendritic area. The strongest effect of Ru addition was found to be Re segregation. Increasing the Ru content up to 6 wt.% significantly alleviated the microsegregation of Re, which resulted in a decrease of Re accumulation in the dendritic core. The influence of Ru on the microstructural stability toward the topologically close-packed phase formation was discussed based on Scheil type calculations with experimentally determined microsegregation results.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.469-486
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• 2021

Vietnam is a country where the largest number of Korean companies have branched out, and calibers who can speak Vietnamese are on great demands. In the multicultural classroom, students of Vietnamese background occupy the first or second largest composition among students with multicultural backgrounds; therefore, if teachers can teach in Vietnamese, the positive effects can be promising. This study presents and evaluates a Vietnamese language class developed and operated for the first time in Korea by a university to raise prospective teachers' global-multicultural competences. Two series of the classes were conducted during two vacations of 2018, and 20 students participated. As a results, the groups showed a significant increase in the global-multicultural competences; About 95 percent of the participants demonstrated improvement in the competences. The participants stated opinions: the classes should expand to offer opportunities for many other students who may want to acquire Vietnamese; the participants had better understandings of the Vietnamese cultures, envisioned their role as a Vietnamese speaker and suggested extended opportunities for contacts with Vietnamese cultures. The study hopes that other universities apply the educational model and the case study and that, as a result, teachers can contribute to building harmonious Korean-Vietnamese relations using Vietnamese.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.85-91
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• 2021

The DAPA (Defense Acquisition Program Administration) has been operating the DQ mark certification since 2012 to certify the superior technology and quality of munitions. On the other hand, the current DQ mark certification can not directly provide DQ mark certification to software because it is impossible to verify the quality of software alone. Therefore, this study analyzed domestic/overseas software quality evaluation/certification standards to find a way to verify the quality of software in the DQ mark certification. Among them, the method of applying the GS certification according to the international standard ISO/IEC 25000 series to the DQ mark certification was suggested as an improvement plan, and DQ mark certification verified the quality of software and provided certification. An attempt was made to expand the certification scope of DQ mark certification. This paper proposes that the DQ mark can be given to the system software by introducing GS certification to the DQ mark certification. To this end, an improved procedure for omitting the factory audit and verification by submitting a GS certificate for product evaluation is proposed. This is expected to increase defense exports using the granted DQ mark and improve the quality of defense software products through GS certification.

• Knowledge Management Research
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• v.22 no.4
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• pp.135-155
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• 2021

With the emergence of various types of social media and the diversification of their roles, it has become essential for marketers to understand how different types of social media influence consumers' purchase decisions differently and derive more detailed strategies by social media types. This study classifies social media into two types-expression-focused social media and relationship-focused social media-and investigates the relationship between consumer purchases and social media mentions by type. Using the Seoul bike-sharing data and time-series data for social media mentions, we apply the VAR model with Exogenous Variables (VARX). We find that the increase of product mentions in expression-focused social media positively affects both the number of new customers (customer acquisition) and the number of shared bike rentals, while that in relationship-focused social media negatively affects the number of new customers only. In addition, as new customers increase, the product mentions in both types of social media increase. On the other hand, the number of bike rentals has no significant effect in increasing social media mentions regardless of type. This study contributes to the social media and sharing economy literature and provides managerial implications for establishing sophisticated social media marketing in bike-sharing businesses.

• Korean Journal of Remote Sensing
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• v.38 no.3
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• pp.299-309
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• 2022

Recently, The sea water temperature around Korean Peninsula is steadily increasing. Water temperature changes not only affect the fishing ecosystem, but also are closely related to military operations in the sea. The purpose of this study is to suggest which model is more suitable for the field of water temperature prediction by attempting short-term water temperature prediction through various prediction models based on deep learning technology. The data used for prediction are water temperature data from the East Sea (Goseong, Yangyang, Gangneung, and Yeongdeok) from 2016 to 2020, which were observed through marine observation by the National Fisheries Research Institute. In addition, we use Long Short-Term Memory (LSTM), Bidirectional LSTM, and Gated Recurrent Unit (GRU) techniques that show excellent performance in predicting time series data as models for prediction. While the previous study used only LSTM, in this study, the prediction accuracy of each technique and the performance time were compared by applying various techniques in addition to LSTM. As a result of the study, it was confirmed that Bidirectional LSTM and GRU techniques had the least error between actual and predicted values at all observation points based on 1 hour prediction, and GRU was the fastest in learning time. Through this, it was confirmed that a method using Bidirectional LSTM was required for water temperature prediction to improve accuracy while reducing prediction errors. In areas that require real-time prediction in addition to accuracy, such as anti-submarine operations, it is judged that the method of using the GRU technique will be more appropriate.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.3
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• pp.187-193
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• 2022

In the Yeongdong region of Gangwon-do, coastal areas are important resources in terms of cultural, social and economic aspects. However, the coast of Gangwon-do is experiencing severe erosion, and it is concerned that its adverse effects will gradually increase. In this study, coastline changes of Yangyang and Gangneung in Gangwon-do were tracked and analyzed over a long period of time. In order to build time series image data, aerial photos from the 1940s to the present were mainly used, and data from CORONA satellite, which operated from the 1960s to the early 1970s, were collected and used together. Using 51cm resolution ortho image and 2m resolution Digital Elevation Model(DEM) as reference, ground control points were selected to perform geometric correction on the aerial photos and CORONA images. Subsequently, Canny edge detector applied to these images to extract the coastlines. As a result of analyzing the extracted and vectorized coastlines by overlaying them in chronological order, erosion and deposition occurring around the artificial structures and on the nearby beaches were observed. In this study, the effect of seasonal variation, tide, and various coastal management including the beach filling were not considered. Because coastal erosion is greatly affected by geographic factors, each local government must find its own solution. Continuous research and local data accumulation are required.