• Journal of the Mineralogical Society of Korea
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• v.32 no.2
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• pp.79-86
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• 2019

The white aluminum phases in acid mine drainage usually precipitates when mixed with stream waters with relatively high pH. The minerals in white precipitates play important roles in controlling the behavior of heavy metals by adsorbing and coprecipitation. By the phase transition of these minerals in white precipitates, dissolution and readsorption of heavy metals may occur. This study was conducted to obtain preliminary information on the phase transition of the mineral phases in white precipitates. In this study, the mineral phase changes in the white precipitates collected from the stream around Dogye Mining Site over time were investigated with different pH values and temperatures. White precipitates consist mainly of basaluminite, amorphous $Al(OH)_3$ and a small amount of $Al_{13}$-tridecamer. During aging, the incongruent dissolution of the basaluminite occurs first, increasing the content of the amorphous $Al(OH)_3$. After that, pseudoboehmite is finally precipitated following the precursor phase of pseudoboehmite. At $80^{\circ}C$, this series of processes was clearly observed, but at relatively low temperatures, no noticeable changes were observed from the initial condition with coexisting basaluminite and amorphous $Al(OH)_3$. At high pH, the desorption of $SO{_4}^{2-}$ group in basaluminite was initiated to promote phase transition to the pseudoboehmite precursor. Over time, the solution pH decreases due to the dissolution and phase transition of the minerals, and even after the precipitation of pseudoboehmite, only the particle size slightly increased but no clear cystal form was observed.

• Korean Journal of Cognitive Science
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• v.33 no.1
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• pp.77-93
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• 2022

Previous studies have reported that a plausible reference point has a greater anchoring effect than an extreme reference point. It is also known that the anchoring effect decreases when the individual's level of knowledge related to a given item is high. However, there has been no study examining the interaction of the plausibility of the reference point and the difficulty of the given question. Therefore, in this study, the effect of the reference plausibility and the difficulty of the questions on the anchoring effect were examined. The relationship between the response confidence and the anchoring effect was also examined. To do so, easy and difficult questions, plausible and extreme reference points were selected through preliminary research. The experiment was conducted following the 'standard anchoring task procedure'. As results, the extremity of the reference point and the difficulty of the question affected the size of the anchoring effect respectively. The difficulty of the question also affected the confidence of the response. Specifically, when a plausible reference point was presented and when a difficult question was presented, the anchoring effects were increased. In addition, the lower the confidence in one's performances, the greater the influence of the reference point when an extreme reference point was presented. These results show that the plausibility of the given reference point and the difficulty of the item have different effects on the magnitude of the anchoring effect and the degree of confidence. The results of this study support the attitude change perspective regarding the anchoring effect, which suggests that the anchoring effect varies depending on the characteristics of the reference point and the individual's knowledge.

• Journal of the Korean Society of Radiology
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• v.16 no.6
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• pp.787-797
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• 2022

The purpose of this study was to confirm the reduction of pain and symptom relief of Parkinson's disease by vertically stimulating the spine through the application of a mechanical bed capable of thermal and massage stimulation. For this purpose, after confirming the segmental motion of the spine due to the use of a medical combination stimulation bed for Parkinson's disease patients, VAS, ODI, gait ability, and spiral drawing tests were performed, and the relationship between the variables was identified. In the 10-day visual analog scale and evaluation of low back pain dysfunction, the average trend of decreasing after bed use was confirmed. For walking ability, a decrease in the moving time and an increase in the moving distance were observed. In the spiral drawing test, the mean test time after using bed was significantly lower than before. As a result, it suggested the possibility of using it as an auxiliary method for recovery and pain relief of Parkinson's disease patients due to spinal segmental movement with mechanical heating and massage. However, this study is a preliminary study, and there is a small number of subjects, so additional research is needed that considers the number and condition of future subjects in detail.

• Korean Journal of Culture and Social Issue
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• v.28 no.4
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• pp.717-748
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• 2022

This study was conducted to develop and validate the social media anxiety and anger scale(SAACS), which measures emotions, especially anxiety and anger that can be contagioned to individuals, through posts and comments on social conflicts in social media. A literature search was conducted on social conflicts in social media, 12 factors(anxiety and anger about gender, crime, generation, wealth gap, politics, region) were selected. Then questions were developed after looking into previous literature and reviewing community posts and comments, and 105 preliminary questions were selected. Following the results of exploratory and confirmatory factor analysis for people aged 20 to 39 age group, SAACS was revised to 12 factors(anxiety and anger about gender, crime, generation, wealth gap, politics, and region) and 48 questions. When verifying the validity, the SAACS had a significant level of correlation with the SNS addiction tendency scale, Rosenberg self-esteem scale, Korean aggression questionnaire(K-AQ), and the state-trait anxiety inventory(STAI-X). SAACS showed no significant correlation with Korean emotional contagion scale(K-ECS). Finally, based on the results, the implications of this study and suggestions for future studies were discussed.

• Analytical Science and Technology
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• v.19 no.3
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• pp.255-262
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• 2006

In this study, we attempted to evaluate the sorptive loss of VOC upon their contact with different material surfaces including clothing pieces. For the purpose of this study, we developed a method to evaluate such loss by employing a filter holder pack in the thermal desorption line of the GC/FID system. The calibration curves of different aromatic VOCs including benzene, toluene, and xylene were made by loading them at different quantities through the analytical line. A series of experiments were conducted repetitively to draw calibration data sets for all three materials covering glass fiber, cotton, and nylon. The results were then compared in terms of both material types and of VOC types. The extent of sorptive loss increased in a highly systematic manner across different materials such as glass fiber, cotton, and nylon. The patterns of sorptive loss also increased gradually across VOC type such toward in the direction of increasing molecular weights: benzene, toluene, and xylene. According to this experimental study, it is concluded that sorptive behavior of pollutint compounds like VOC can be controlled by the combined effects of both chemical properties and material characteristics.

• 한국노년학
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• v.29 no.1
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• pp.215-230
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• 2009

In this study, we compared Korean retirees' retirement wealth adequacy with their subjective recognition and examined determinants affecting the retirement wealth adequacy. The data were drawn from the 2007 Korean Retiree Survey carried out by the Korean Investors Education Foundation. The major results of this study were as follows. The analysis suggested that Korean retirees(age 50 and over) were not well prepared financially. When using their assets(except for their residence), only 23.2% had accumulated enough wealth to meet their expenses for the remainder of their life. 25.7% of retirees subjectively considered themselves to be adequately covered. The comparison results showed that 23.8% of retirees' subjective recognition was not in accord with the estimation results. One of the most troubling groups is the 12.9% of retirees who were in the inadequacy group even though they considered themselves to be in the adequacy group. Retirement wealth adequacy determinants were quite different between objective adequacy and subjective recognition. Household income and ownership of a residence have positive effects on the retirement wealth adequacy. Also, the importance of retirement planning to retirement wealth adequacy is statistically confirmed. Based on these findings, This research suggests private retirement planning and political implications for retirees and preretired households.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.671-680
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• 2022

This study evaluated the consistency between the web-based and paper-based mibyeong and cold-heat pattern questionnaire, the Korean medicine-based tool for diagnosing and classifying health status. First, a web-based survey was conducted on 72 ordinary people; subsequently, a paper-based survey was conducted after a certain time interval. The equivalence between the web-based and paper-based surveys was evaluated on the basis of the consistency between scores using the Intraclass Correlation Coefficient (ICC) and Bland-Altman methodology. The mibyeong questionnaire showed high reliability for the web-based and paper-based surveys (ICC=0.95, 95% CI 0.92 - 0.97), and the cold-heat pattern questionnaire showed high reliability for both cold syndrome (ICC=0.98, 95% CI 0.96 - 0.99) and heat syndrome (ICC=0.9, 95% CI 0.83 - 0.93). The difference in average scores between the two survey methods was -0.25 for the mibyeong survey, -0.17 for the cold syndrome, and 0.11 for the heat syndrome, showing a similar pattern. Among the respondents, 84% showed positive satisfaction with the web-based survey, and 80% preferred the web-based survey. Overall, this study confirmed the reliability and feasibility of the web-based survey methods for the mibyeong and cold-heat pattern questionnaire. This could be a useful tool for the follow-up of subjects in long-term cohort studies.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.275-283
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• 2023

The progressive wear of teeth is a physiologic process of aging, but excessive wear can lead to occlusal disharmony, tooth sensitivity and pulp exposure, decreased masticatory efficiency, and aesthetic problems. It should be treated by evaluating the cause of tooth wear and establishing a stable centric relation with appropriate vertical dimension of occlusion and occlusal plane. The present case report successfully rehabilitated a full-mouth case of a severely worn dentition with the use of digital facebow transfer and virtual articulator.

• Journal of Industrial Convergence
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• v.21 no.11
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• pp.13-27
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• 2023

This study aims to contribute to the reduction of the failure rate and social costs resulting from business failures by analyzing factors that affect the insolvency of social enterprises, as the role of social enterprises is increasing in our economy. The data used in this study were classified as normal and insolvent companies among social enterprises (including prospective social enterprises) that were established between 2009 and 2018 and received credit guarantees from credit guarantee institutions as of the end of June 2022. Among the collected data, 439 social enterprises with available financial information were targeted; 406 (92.5%) were normal enterprises, and 33 (7.5%) were insolvent enterprises. Through a literature review, eight non-financial factors commonly used for insolvency prediction were selected. The cross-analysis results showed that four of these factors were significant. Logistic regression analysis revealed that two variables, including corporate credit rating and the personal credit rating of the representative, were significant. Financial factors such as debt ratio, sales operating profit rate, and total asset turnover were used as control variables. The empirical analysis confirmed that the two independent variables maintained their influence even after controlling for financial factors. Given that government-led support and development policies have limitations, there is a need to shift policy direction so that various companies aspiring to create social value can enter the social enterprise sector through private and regional initiatives. This would enable the social economy to create an environment where local residents can collaborate to realize social value, and the government should actively support this.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.445-471
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• 2023

Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.