• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.94-99
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• 2021

It was found that mixing patterns suddenly changed at an impeller rotation speed in a dished bottom vessel with dual Rushton turbines. Two isolated mixing regions like doughnuts rings generated at a low rotational speed and three isolated mixing regions generated at a higher speed. This phenomenon was observed at the mixing condition in transition area, where the power number with baffle was the same as that without baffle. We found a phenomenon in which the flow state in a dish-bottom agitation tank equipped with a two-stage Rushton turbine blade changes at a certain rotational speed. In the laminar flow region, the isolated stable donut rings were formed even when the rotational speed was changed, and no specific variation in the mixing pattern was observed. In the transition region, the two isolated thick unmixed donut rings do not change even if the rotation speed is changed in the flat bottom vessel, whereas in the dished bottom vessel, when the rotation speed is 450 rpm, the two isolated thick unmixed donut rings are changed to three isolated thin donut rings and then improved mixing. In the dished bottom vessel, in the range of Re=138~178, the isolated ring-shaped unmixed region appeared in three places and the size was also large. But in the flat bottom vessel, the isolated thick ring-shaped unmixed region appeared in two places in Re=116~176 and the size was also small. It appeared in two places, and the size was also small. The condition in which this phenomenon is observed is a transition region, and it was found that when the baffle plate is attached, the power number starts to increase compared to when the baffle plate is not present. In addition, when the mixing Reynolds number exceeded 300 and a slight turbulence was mixed in the flow state, the disconnection of these flow pattern was resolved and the mixture was completely mixed.

• Journal of Ginseng Culture
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• v.4
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• pp.59-102
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• 2022

Since there were only few countries that could find wild ginseng grown in nature, the culture of digging wild ginseng was only developed in a small number of countries. In a time when the orthodox head-Simmemani has disappeared, the tangible and intangible culture of Simmemani (wild ginseng digger) is disappearing more and more with the passage of time. So far, the conducted research on wild ginseng diggers was very partial and simplistic as follows: ① Research on the argot of Simmemani, ② Research on the customs of Simmemani, ③ Research on the change of customs of Simmemani, ④ Additional records through interview with Simmemani. Accordingly, no comprehensive study on the Simmemani culture has been done yet. This study supplements the historical materials that were not reflected in previous studies, and discuss on diverse subjects including the definition and classification of wild ginseng, the distribution of wild ginseng and Simmemani, interpretation of wild ginseng digging from a legal and social point of view, the organization responsible for the digging, determination of the date of entering the mountain, preparations, taboos, departure and entry into a mountain, religious events, psalmbook, dream interpretation, search and discovery of wild ginseng, digging, profit sharing, the amount of harvested wild ginseng, and the price of wild ginseng. In addition, Korean wild ginseng digging culture was comprehensively studied by attaching the photos and illustrations of historical documents with the psalmbook of the head-Simmemani.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1489-1503
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• 2022

Drone and sensor technologies are enabling digitalization of agricultural crop's growth information and accelerating the development of the precision agriculture. These technologies could be able to assess damage of crops when natural disaster occurs, and contribute to the scientification of the crop insurance assessment method, which is being conducted through field survey. This study was aimed to calculate lodged damage rate from the vegetation indices extracted by drone based RGB images for soybean. Support Vector Classifier (SVC) models were considered by adding vegetation indices to the Crop Surface Model (CSM) based lodged damage rate. Visible Atmospherically Resistant Index (VARI) and Green Red Vegetation Index (GRVI) based lodged damage rate classification were shown the highest accuracy score as 0.709 and 0.705 each. As a result of this study, it was confirmed that drone based RGB images can be used as a useful tool for estimating the rate of lodged damage. The result acquired from this study can be used to the satellite imagery like Sentinel-2 and RapidEye when the damages from the natural disasters occurred.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.276-280
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• 2021

The oxygen transfer rate at the liquid surface of the reciprocally shaking vessel was studied. The required power of the reciprocally shaking vessel was not proportional to the shaking frequency, unlike the rotational shaking vessel, and the liquid level suddenly fluctuated greatly at a certain frequency as the flow pattern in the vessel was a left and right wave flow different from that of the rotational shaking that has a rotational flow. The effect of the shaking frequency on the required power in the reciprocally shaking vessel was very complex, such as less power required than the rotational shaking vessel when the shaking frequency is more than 3 s-1, but the required power for the range of the generated rotational flow in the reciprocally shaking vessel could be correlated with the equation that was reported for the rotational shaking vessel. The kLa (mass transfer capacity coefficient) in the reciprocally shaking vessel also increased in a complex pattern because the required power for shaking was not consumed in a simple pattern, unlike kLa in the rotational shaking vessel, which increases linearly with increasing frequency. The kLa of the reciprocally shaking vessel was larger than the kLa of the rotational shaking vessel, and as the kLa value increased, the difference between them increased sharply. As a result, the oxygen transfer rate in the reciprocal motion was greater than that of the rotational motion, and could be correlated with the required power per unit volume.

• Journal of the Korean Regional Science Association
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• v.38 no.4
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• pp.3-17
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• 2022

This study aims to empirically analyze the impacts of the topographic characteristics of residential areas and the characteristics of land use and transportation on average trip distance of the senior citizens in Busan Metropolitan city. Multiple regression is conducted to accomplish the purpose of this study, and the conclusions and policy implications of the analysis are as follows. First, the average and standard deviation of the residential areas are significantly related to average trip distance of the senior citizens. Thus, urban transportation policies need to take account of the topographic characteristics of the residential areas. Second, average distance from the nearest subway station and density of bus stops have positive and negative association respectively. Mobility improvement polices for senior citizens should consider urban spatial structure and different approach processes to transportation facilities by modes. Third, mobility and residential environment improvement policies for senior citizens should take into account different sociodemographic characteristics by locations. This shows that the mobility convenience policy for senior citizens is more necessary than any other policy for administrative dong, where traffic access is relatively low and the single senior citizen population is concentrated.

• The Korean Journal of Coaching Psychology
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• v.5 no.1
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• pp.1-32
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• 2021

The purpose of this study was to investigate the effects of the online coaching program on improving eating habit behaviors. The online coaching program was based on the model of habit behaviors change process(Tak et al., 2019) and the success factors on improving eating habit behaviors(Choi et al., 2020), and previous research showing the effects of habit change. Participants were 20 adults, selected through telephone interviews over the age of 19 in the metropolitan area. They were divided into the experiment and control groups, and participated one-on-one coaching program. Data of 17 people were used for the final analysis, and weight, dietary habits, eating behaviors, dietary self-efficacy, self-regulation, and life satisfaction were measured at two times(pre and post). Results showed that there were significant interaction effects between time interval and groups for all the dependent variables except self-regulation and life satisfaction. In other words, there were significant changes in weight, dietary habits, eating behaviors, dietary self-efficacy in the experimental group between time interval, whereas there were no significant changes for the control group. Based on these results, the significance and practical implications, limitations of this research, and suggestions for further research were discussed.

• SUVANNABHUMI
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• v.2 no.1
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• pp.55-94
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• 2010

Even Faxian(法顯)'s Gaosengfaxianchuan (『高僧法顯傳』) and Iching(義淨)'s Nanhaijiguineifachuan (『南海寄歸內法傳』) are regarded as very important and useful documents to study the southeast asian buddhist culture, it is very difficult to grasp the contemporary state of those area because their descriptions are very brief and implicit. Therefore this essay aimed an in-depth reading their documents as original texts of modern understanding of those area, and tried to make a new views to approach the southeast asian buddhist culture by some more historically and concretely. At the early 5th century when Faxian(法顯) arrived, Buddhism was flourished in Sri Lanka. Because already a long time passed since the Saṇgha was schismatized into conservative and progressive at around the dominical year, he mentioned nothing about the conflict or disharmony of two orders. And the faith of Buddha tooth relic, which had been uprisen at 50 years ago from Faxian's visiting, was concretely established as a representative religion of Sri Lanka. According to his record, the carrying ritual of this Buddha tooth was performed very magnificently as similar with recent Korean Youngsan ceremony(靈山齋). In the mean time, it looks there were many sculptures of Buddha image made of precious stone of special product from Sri Lanka. The faith of Buddha-pāda(the Buddha's foot-prints) was also generalized at that time. The most famous monk of his contemporary Sir Lanka was Buddhaghosa, the author of Visuddhi-magga, but it is not sure that Faxian had met him. It can be suspected that the funeral in which Faxian participated could be belonged to him, or the Visuddhi-magga was writing at the peak during Faxian's staying. On the way to return to China, Faxian embarked an indigenous ship around Indonesia. It means there were no chinese trade ship which he can use. So the trade between china and southeast asia was advanced by south asian ships, and the chinese ships were not yet joined at that time so activity. And at least until that time, it looks there were no any remarkable buddhist movement in the southeast asian countries by where he stopped. In contrast, the southeast asian world which be seen by Iching had already experienced a lot of changes. He was impressed by the high quality buddhist culture of those area, and insisted to accept it to china. Further, he analyzed the sects of buddhism which were prevalent around the southeast asia in his contemporary time, and tried to make a good relationship with each native monks for learning from them. It looks the center of those exchanges may be Śrīvijaya of Indonesia. He also mentioned the situation of the late 7th century's Funan(扶南) in Cambodia. At that time, the buddhist Saṇgha was oppressed by newly rising Khmer(眞臘). On the other hand, he described the points of sameness and difference in detail between Indian and southeast asian buddhist culture in the field of ritual as like the practical use of garments, buddha images, and daily recited scriptures. There must be a lot of another aspects which this essay couldn't gather up or catch from these documents. Nevertheless, I hope this essay can help the researchers of this field and will wait for any advices and comments from them.

• The Journal of KAIRB
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• v.5 no.2
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• pp.51-58
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• 2023

Purpose: To validate the effectiveness of obtaining consent education on errors in the consent process and to develop the education program for researchers. Methods: From February 2019 to February 2022, a 30-minute, 1:1 face-to-face consent education developed using the ADDIE model was conducted on 78 nurses as principal investigators. An informed consent audit tool, which includes 6 items developed by Asan Medical Center Human Research Protection Center, was used to analyze errors in obtaining informed consent process. Data analysis was performed using the SPSS ver. 25.0, and the Mann-Whitney U-test and χ²-test were utilized to verify the difference in errors between the experimental and control groups. Results: The participants consisted of 42 in the experimental group and 36 in the control group, with no statistically significant difference between the 2 groups. Both 2 groups showed the highest frequency of documentation errors, followed by format errors, errors related to a suitability of investigator, participant, or participant's legally acceptable representative, witness and confidentiality issues. After education, there was a significant decrease in both format errors (p=0.002) and documentation errors (p<0.001) in the experimental group. The proportion of participants without any errors in all items was higher in the experimental group (35.7%) compared to the control group (5.6%), and this difference was statistically significant (p=0.001). Conclusion: The obtaining consent education program was found to be effective in reducing informed consent errors. This study emphasizes the importance of education, suggesting the need for its expansion and accessibility, as well as the necessity for all researchers conducting clinical studies to receive the obtaining consent education.

• Journal of Korean Society of Rural Planning
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• v.30 no.1
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• pp.57-66
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• 2024

This study aimed to develop a precise vegetation cover classification model for small streams using the combination of drone remote sensing and support vector machine (SVM) techniques. The chosen study area was the Idong stream, nestled within Geosan-gun, Chunbuk, South Korea. The initial stage involved image acquisition through a fixed-wing drone named ebee. This drone carried two sensors: the S.O.D.A visible camera for capturing detailed visuals and the Sequoia+ multispectral sensor for gathering rich spectral data. The survey meticulously captured the stream's features on August 18, 2023. Leveraging the multispectral images, a range of vegetation indices were calculated. These included the widely used normalized difference vegetation index (NDVI), the soil-adjusted vegetation index (SAVI) that factors in soil background, and the normalized difference water index (NDWI) for identifying water bodies. The third stage saw the development of an SVM model based on the calculated vegetation indices. The RBF kernel was chosen as the SVM algorithm, and optimal values for the cost (C) and gamma hyperparameters were determined. The results are as follows: (a) High-Resolution Imaging: The drone-based image acquisition delivered results, providing high-resolution images (1 cm/pixel) of the Idong stream. These detailed visuals effectively captured the stream's morphology, including its width, variations in the streambed, and the intricate vegetation cover patterns adorning the stream banks and bed. (b) Vegetation Insights through Indices: The calculated vegetation indices revealed distinct spatial patterns in vegetation cover and moisture content. NDVI emerged as the strongest indicator of vegetation cover, while SAVI and NDWI provided insights into moisture variations. (c) Accurate Classification with SVM: The SVM model, fueled by the combination of NDVI, SAVI, and NDWI, achieved an outstanding accuracy of 0.903, which was calculated based on the confusion matrix. This performance translated to precise classification of vegetation, soil, and water within the stream area. The study's findings demonstrate the effectiveness of drone remote sensing and SVM techniques in developing accurate vegetation cover classification models for small streams. These models hold immense potential for various applications, including stream monitoring, informed management practices, and effective stream restoration efforts. By incorporating images and additional details about the specific drone and sensors technology, we can gain a deeper understanding of small streams and develop effective strategies for stream protection and management.

• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.242-249
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• 2008

Recently, AVO analysis has been widely used in oil exploration with seismic subsurface section as a direct indicator of the existence of the gas. In the case of the deep reservoirs like the gas reservoirs in the East-sea, it is often difficult to observe AVO responses in CMP gathers even though the bright spots are shown in the stacked section. Because the reservoir becomes more consolidated as its depth deepens, P-wave velocity does not decrease significantly when the pore fluid is replaced by the gas. Thus the difference in Poisson's ratio, which is a key factor for AVO response, between the reservoir and the layer above it does not increase significantly. In this study, we analyzed the effects of Poisson's ratio difference on AVO response with a variety of Poisson's ratios for the upper and lower layers. The results show that, as the difference in Poisson's ratio between the upper and lower layers decreases, the change in the reflection amplitude with incidence angle decreases and AVO responses become insignificant. To consider the limitation of AVO responses shown in the gas reservoir in East-sea, the velocity model was made by simulation Gorae V structure with seismic data and well logs. The results of comparing AVO responses observed from the synthetic data with theoretical AVO responses calculated by using material properties show that the amount of the change in reflection amplitude with increasing incident angle is very small when the difference in Poisson's ratio between the upper and lower layers is small. In addition, the characteristics of AVO responses were concealed by noise or amplitude distortion arisen during preprocessing. To overcome such limitations of AVO analysis of the data from deep reservoirs, we need to acquire precisely reflection amplltudes In data acquisition stage and use processing tools which preserve reflection amplitude in data processing stage.