• Clean Technology
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• v.27 no.2
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• pp.146-151
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• 2021

Pure and Sm ion doped BiVO₄ catalysts were synthesized using a conventional hydrothermal method and characterized by XRD, DRS, SEM, and PL. We also examined the activity of these materials on the photocatalytic decomposition of rhodamine B under visible light irradiation. The doping of Sm ion into BiVO₄ catalyst changed the ms-BiVO₄ crystal structure into the tz-BiVO₄ crystal structure in the low synthesis temperature. Light absorption analysis using DRS showed that all the catalysts displayed strong absorption in the visible range of the electromagnetic spectrum regardless of Sm ion doping. In addition, an amorphous morphology was shown in the pure BiVO₄ catalyst, but the morphology of the BiVO₄ catalyst doped with Sm ion was changed into an ellipse shape and also the particle size decreased. In the photocatalytic decomposition of rhodamine B, Sm ion doped BiVO₄ catalyst showed higher photocatalytic activity than the pure BiVO₄ catalyst. In addition, the Sm3-BVO catalyst doped with 3% Sm ion showed the highest photocatalytic activity, as well as the highest formation rate of OH radicals (•OH) and the highest PL peak. This result suggests that the formation rate of OH radicals produced in the interface between the photocatalyst and water is well correlated with the photocatalytic activity.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.679-684
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• 2011

Branched polypropylenes (LCB-PP) with a long chain branch were prepared by the solid-state and molt-state reaction. Divinylbenzene (DVB), 1,4-benzenediol (RES), and furfuryl sulphide (FS) were used as branching agents of fabricate LCB-PP/silicate composites. Chemical structures, thermal properties, and rheological properties of the LCB-PP were determined by FT-IR, DSC, TGA, and dynamic rheometer (ARES). The chemical structure of the LCB-PP was confirmed by the existence of =C-H stretching peak of the branching agent at $3100cm^{-1}$. From DSC and TGA results, the melting reaction was more effective than the solid state reaction in the manufacture of LCB-PP, which was additionally certified by rheological properties. Based on rheological properties, FS was the best for branching efficiency of PP. Compared to PP, LCB-PPs indicated an increase of complex viscosity in the low frequency and shear thinning tendency, and G'-G" plot represented an increase in elasticity and the heterogeneousness in a melt state. Rheological properties of LCB-PP/silicate composites were observed with the silicate content. When 5 wt% silicate was added in LCB-PP, distinct changes in the shear thinning and the slope of G'-G" plots were observed.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.327-335
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• 2021

In this study, we sought to investigate how animal-assisted therapy using therapy dogs affects the relationship between children's self-esteem and age. The subjects of the study were 20 children in the lower grades of elementary school in I City who were recommended by a school social worker and their homeroom teacher, and 10 control groups of 10 experimental groups were selected. From October 1st to December 17th, 2019, the program conducted an animal-mediated treatment program once a week for 50 minutes for 12 sessions. Using SPSS 20.0 for verification, the experimental and control groups were analyzed by performing pre- and post-relationship calm scale measurements of self-esteem and age. As a result, first, the overall self-esteem of the experimental group (Z = -2.75, p<.05), the self-esteem at home (Z = -2.02, p<.05), and the academic self-esteem (Z = -2.06, p<. 05) shows a statistically significant difference. Second, significant differences were shown in overall peer relationships(Z=-3.83, p<.05), scrupulosity(Z=-2.68, p<.05), and empathy(Z=-2.81, p<.05) in the experimental population. Therefore, in this study, it was confirmed that animal-assisted therapy using therapy dogs had a positive effect on the relationship between children's self-esteem and age.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.371-379
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• 2021

The personality education of the existing university is mainly focused on occupational ethics education or basic education, but the purpose and method of the personality education program is changed in preparation for the 4th industry and the related occupational personality education program is needed. In Korea, however, there is a lack of research on the development of educational programs for occupational personalities that Health care workers should have. Therefore, this study aims to confirm the effect by developing and applying a program for occupational personality education for Health care workers required for the 4th Industrial Revolution based on case-based learning. In this study, general cases and occupational cases were developed, and research tools were developed to verify the effectiveness of the occupational personality education program. The program developed in this study was provided four times for 52 students in the second and third grades college and university. This study was performed with a single group pre-post design. The data were analyzed by means of mean, standard deviation, and paired t-test. By applying the program developed in this study, accountability, honesty, consideration, collaboration, communication, and competency were improved. This confirmed the positive effect of vocational character education

• Clean Technology
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• v.26 no.4
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• pp.311-320
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• 2020

In this study, the photocatalytic degradation of rhodamine B (RhB), methyl orange (MO) and methylene blue (MB) was carried out under visible light irradiation using CdS and CdZnS/ZnO photocatalysts prepared by a simple precipitation method. This study focused on examining the effect of physicochemical properties of dye and photocatalyst on the reaction pathway of photocatalytic degradation. The prepared photocatalysts were characterized by XRD, UV-vis DRS and XPS. Both the CdS and CdZnS/ZnO photocatalysts exhibit an excellent absorption in the visible light and the UV light regions. It was observed that the photocatalytic degradation of MO proceeds via the same reaction mechanism on both the CdS and CdZnS/ZnO photocatalysts. However, the photocatalytic degradation of RhB and MB was found to proceed through a different reaction pathway on the CdS and CdZnS/ZnO catalysts. It is interesting to note that MB dimer was formed on the CdS catalyst at the beginning of the photocatalytic reaction, while the MB monomer was degraded during the overall photocatalytic reaction on CdZnS/ZnO. The above results may be mainly ascribed to the difference of band edge potential of the conduction band in the CdS and CdZnS/ZnO semiconductors and the adsorption property of dye on the catalysts.

• Journal of Korea Water Resources Association
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• v.54 no.8
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• pp.553-566
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• 2021

River confluence is often characterized by shear layer and the associated strong mixing. In natural rivers, the main channel and its tributary can be separated by the shear layer using contrasting colors. The shear layer can be easily observed using aerial images from satellite or unmanned aerial vehicles. This study proposes a low-cost identification method extracting geographic features of the shear layer using RGB aerial image. The method consists of three stages. At first, in order to identify the shear layer, it performs image segmentation using a Gaussian mixture model and extracts the water bodies of the main channel and tributary. Next, the self-organizing map simplifies the flow line of the water bodies into the 1-dimensional curve grid. After that, the curvilinear coordinate transformation is performed using the water body pixels and the curve grid. As a result, the shear layer identification method was successfully applied to the confluence between Nakdong River and Nam River to extract geometric shear layer features (confluence angle, upstream- and downstream- channel widths, shear layer length, maximum shear layer thickness).

• Tunnel and Underground Space
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• v.32 no.2
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• pp.131-143
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• 2022

The lunar exploration autonomous vehicle operates based on the lunar topography information obtained from real-time image characterization. For highly accurate topography characterization, a large number of training images with various background conditions are required. Since the real lunar topography images are difficult to obtain, it should be helpful to be able to generate mimic lunar image data artificially on the basis of the planetary analogs site images and real lunar images available. In this study, we aim to artificially create lunar topography images by using the location information-based style transfer algorithm known as Wavelet Correct Transform (WCT2). We conducted comparative experiments using lunar analog site images and real lunar topography images taken during China's and America's lunar-exploring projects (i.e., Chang'e and Apollo) to assess the efficacy of our suggested approach. The results show that the proposed techniques can create realistic images, which preserve the topography information of the analog site image while still showing the same condition as an image taken on lunar surface. The proposed algorithm also outperforms a conventional algorithm, Deep Photo Style Transfer (DPST) in terms of temporal and visual aspects. For future work, we intend to use the generated styled image data in combination with real image data for training lunar topography objects to be applied for topographic detection and segmentation. It is expected that this approach can significantly improve the performance of detection and segmentation models on real lunar topography images.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.29-35
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• 2022

This paper proposes a fuel cell education framework installed on a Metaverse environment, which is to reduce the burden of education costs and improve the effect of education or learning. This Meta-Fuel cell platform utilizes the Unity 3D Web and enables not only theoretical education but also hands-on training. The platform was designed and developed to accommodate a variety of unit education contents, such as ppt documents, videos, etc. The platform, therdore, integrates ppt and video demonstrations for theoretical education, as well as software content "STACK-Up" for hands-on training. Theoretical education section provides specialized liberal arts knowledge on hydrogen, including renewable energy, hydrogen economy, and fuel cells. The software "STACK-Up" provides a hands-on practice on assembling the stack parts. Stack is the very core component of fuel cells. The Meta-Fuelcell platform improves the limitations of face-to-face education. It provides educators with the opportunities of non-face-to-face education without restrictions such as educational place, time, and occupancy. On the other hand, learners can choose educational themes, order, etc. It provides educators and learners with interesting experiences to be active in the metaverse space. This platform is being applied experimentally to a education project which is to develop advanced manpower in the fuel cell industry. Its improvement is in progress.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.597-608
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• 2022

Remotely sensed data have been used in various fields, such as disasters, agriculture, urban planning, and the military. Recently, the demand for the multitemporal dataset with the high-spatial-resolution has increased. This manuscript proposed an automatic image matching algorithm using a deep learning technique to utilize a multitemporal remotely sensed dataset. The proposed deep learning model was based on High Resolution Net (HRNet), widely used in image segmentation. In this manuscript, denseblock was added to calculate the correlation map between images effectively and to increase learning efficiency. The training of the proposed model was performed using the multitemporal orthophotos of the National Geographic Information Institute (NGII). In order to evaluate the performance of image matching using a deep learning model, a comparative evaluation was performed. As a result of the experiment, the average horizontal error of the proposed algorithm based on 80% of the image matching rate was 3 pixels. At the same time, that of the Zero Normalized Cross-Correlation (ZNCC) was 25 pixels. In particular, it was confirmed that the proposed method is effective even in mountainous and farmland areas where the image changes according to vegetation growth. Therefore, it is expected that the proposed deep learning algorithm can perform relative image registration and image matching of a multitemporal remote sensed dataset.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.3
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• pp.179-189
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• 2022

Ice and water droplets rise and fall above the freezing altitude under the effects of strong updrafts and downdrafts, grow into hail, and then fall to the ground in the form of balls or irregular lumps of ice. Although such hail, which occurs in a local area within a short period of time, causes great damage to the agricultural and forestry sector, there is a paucity of domestic research toward predicting hail. The objective of this study was to introduce Land-Atmosphere Modeling Package (LAMP) hail prediction and measure its performance for 50 hail events that occurred from January 2020 to July 2021. In the study period, the frequency of occurrence was high during the spring and during afternoon hours. The average duration of hail was 15 min, and the average diameter of the hail was 1 cm. The results showed that LAMP predicted hail events with a detection rate of 70%. The hail prediction performance of LAMP deteriorated as the hail prediction time increased. The radar reflectivity of actual cases of hail indicated that the average maximum reflectivity was greater than 40 dBZ regardless of altitude. Approximately 50% of the hail events occurred when the reflectivity ranged from 30~50 dBZ. These results can be used to improve the hail prediction performance of LAMP in the future. Improved hail prediction performance through LAMP should lead to reduced economic losses caused by hail in the agricultural and forestry sector through preemptive measures such as net coverings.