• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.19-32
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• 2021

In this study, evaluation and consideration of domestic/overseas design, construction, and quality control performed by the authors on the deep cement mixing method were performed, and improvements for the development of the DCM method were suggested in the future. As a result of this study, it was found that the cross-sectional area correction for strength is required during the laboratory test of mix proportion, and caution is required because the extrapolation method may lead to different results from the actual one. Applicable design methods should be selected in consideration of both the improvement ratio and the type of improvement during design, and it was confirmed that the allowable compressive strength to which the safety factor was applied refers to the standard value for stability review and not the design parameters. In the case of the stress concentration ratio, rather than applying a conventional value, it was possible to perform economical design by calculating the experimental and theoretical stress concentration ratio reflecting the design conditions. In the case where pre-boring is expected during construction, if the increased water content is not large compared to the original, there were cases where a major problem did not occur even if the result that did not consider the increase in water content was used. In addition, it was confirmed that when the ratio of the top treatment length to the improved length is high, a small amount of design cement contents per unit length can be injected during construction. In the case of quality control, it was evaluated that D/4~2D/4 for single-axis and D/4 point for multi-axis were optimal for coring of grouting mixtures. As an item for quality control, it is judged that the standard that considers the TCR along with the unconfined compressive strength of grouting mixtures is more suitable for the domestic situation.

• 한국노년학
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• v.40 no.1
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• pp.1-21
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• 2020

The purpose of this study is to examine that basic pension entitlement affects the subjective well-being(SWB) of the elderly. For controlling unobserved heterogeneity, we used fixed effects model for longitudinal data. The data used for this study is KLoSA from 2006 to 2016. The research results are as follows. SWB of non-basic pensioners was higher than for basic pension beneficiaries. Second, when the demographic variables were controlled, SWB of the basic pension recipients was higher then that of non-beneficiaries. Third, the factors affecting SWB were economic satisfaction, marital status, family financial support, employment status, subjective health status, daily life restrictions, gender, and age. Fourth, the effect of basic pension on SWB was positive at the lowest income quartile. The results of this study shows that the basic pension system has a positive effect on the SWB of elderly despite the low benefit level. Therefore, it is necessary to expand the basic pension system to solve poverty problems and improve the quality of life for the aged. Also, various aspects of social support for the low-income vulnerable elderly are needed. Lastly, It was suggested that the benefit level of the basic pension should be raised to have a substantial effect on the low-income class, which is a key policy subject.

• Journal of the Korea Society for Simulation
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• v.31 no.3
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• pp.35-44
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• 2022

In this study, we analyze and forecast quantum computer technology trends. Previous research has been mainly focused on application fields centered on technology for quantum computer technology trends analysis. Therefore, this paper analyzes important quantum computer technologies and performs future signal detection and prediction, for a more market driven technical analysis and prediction. As analyzing words used in news articles to identify rapidly changing market changes and public interest. This paper extends conference presentation of Cha & Chang (2022). The research is conducted by collecting domestic news articles from 2019 to 2021. First, we organize the main keywords through text mining. Next, we explore future quantum computer technologies through analysis of Term Frequency - Inverse Document Frequency(TF-IDF), Key Issue Map(KIM), and Key Emergence Map (KEM). Finally, the relationship between future technologies and supply and demand is identified through random forests, decision trees, and correlation analysis. As results of the study, the interest in artificial intelligence was the highest in frequency analysis, keyword diffusion and visibility analysis. In terms of cyber-security, the rate of mention in news articles is getting overwhelmingly higher than that of other technologies. Quantum communication, resistant cryptography, and augmented reality also showed a high rate of increase in interest. These results show that the expectation is high for applying trend technology in the market. The results of this study can be applied to identifying areas of interest in the quantum computer market and establishing a response system related to technology investment.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.427-439
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• 2021

This study surveyed the recognition on the Korean education for specific purposes targeting student-teachers majoring Korean language education in a Cyber University located in Seoul. 50 among 57 students taking the class participated in this survey. The participants were the students-teachers interested in Korean education for the mission purposes and took the class during the second term in 2020. At the end of the term they participated in this survey. 6 items were objective and 4 items were narrative. Among the narrative ones, one was excluded from analysis. The objective items were investigated by descriptive statics and the narrative items were analyzed with qualitative approach. As a result, most of the participants preferred the combined textbooks with others such as the ones for general and mission purposes rather than the bibles only. They had positive opinions on using the bibles, but proposed that the bibles themselves are not the best choice for improving communicative competence and the text combination is the better choice because of the difficulty of the bibles, the lack of teachers' competence, and the learners' needs. However, while taking this class, they became to be aware of the possibilities of the bibles as textbooks, to possess the concern about the mission areas, to consider the possibilities of application and the educational methods in it, and to reflect the ways for self development. This study suggested several points as follows: the development of diverse textbooks according to situations and learners, two directions of teacher education and the cooperative works, and the necessities of the related departments and classes with mission purposes.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.303-312
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• 2022

Bridges across waterways act as interference factors, that reduce the navigable water area from the perspective of navigation safety. To analyze the safety navigational width of ships navigating bridges across waterways, the optimal traffic distribution based on AIS data was investigated, and ships were classified according to size through k-means clustering. As a result of the goodness-of-fit analysis of the clustered data, the lognormal distribution was found to be close to the optimal distribution for Incheon Bridge and Busan Harbor Bridge. Also, the normal distributions for Mokpo Bridge and Machang Bridge were analyzed. Based on the lognormal and normal distribution, the analysis results assumed that the safe passage range of the vessel was 95% of the confidence interval, As a result, regarding the Incheon Bridge, the difference between the normal distribution and the lognormal distribution was the largest, at 64m to 98m. The minimum difference was 10m, which was revealed for Machang Bridge. Accordingly, regarding Incheon Bridge, it was analyzed that it is more appropriate to present a safety width of traffic by assuming a lognormal distribution, rather than suggesting a safety navigation width by assuming a normal distribution. Regarding other bridges, it was analyzed that similar results could be obtained using any of the two distributions, because of the similarity in width between the normal and lognormal distributions. Based on the above results, it is judged that if a safe navigational range is presented, it will contribute to the safe operation of ships as well as the prevention of accidents.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.429-433
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• 2022

We analyzed both current local policies and in-depth survey data to find out a way to provide job opportunity and income source to local young people in so-called job guarantee system. The young generation in current Korean society has been experiencing both growth without employment and severe economic inequality at the same time, though they should have taken part actively in social development. Their rights for work and survival have also been threatened and losing hope for the future is an widespread symptom in this generation. Kwangju metropolitan city(KMC) has been supporting certain amount of case income and job experience to young people in Kwangju through a local government policy called Kwangju Young Generation Job Experience Dream Service. In spite of high level of satisfaction from the participants, limitations such as below average job performance level of participants and a barrier in the transition to regular position still remain. This study hopes that a case of Kwangju gives pragmatic insights for a realizable path to expanding universal welfare through assuring job opportunity to the young generation in local area.

• Journal of Internet of Things and Convergence
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• v.8 no.3
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• pp.11-20
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• 2022

Corporations operate within long term strategy. The Chief Executive Officer (CEO) makes decisions and has responsibility for all executive activities which affects the corporate performance. If the CEO makes strategic choices through reasonable decision making, it could affect corporate performance and corporate's rise and fall. So the CEO's decision making is very important. As rapid change in the digital technology environment happened, through digital transition, corporations have been working on increasing corporate performance by practical and academic methods. However prior research was restricted to CEO's affect on organization, innovation or innovative activities and there is a lack of research linking CEO's characteristics to digital transition and corporate performance. As the digital age is coming, research on how CEO's characteristics affect digital transition and corporate performance is direly needed. From the case of domestic Big Data corporation RSN Co. ltd's digital transition success, understanding characteristics of CEO, digital transition and corporate performance through prior researches, and developing research model and research proposition was set. Research was performed on RSN co. ltd's case analysis, and how characteristics of CEO's matter on digital transformation and corporate performance. As a result of the proposition, when the CEO conjugates digital technology, the corporation was able to successfully complete digital transition and it also affects corporate performance. Also, this research's other point is that CEO's may have limits on thoughtful decision making. It is judged that it is necessary to try an empirical study in the future.

• Journal of the Korean GEO-environmental Society
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• v.24 no.2
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• pp.5-12
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• 2023

In this study, the amount of heaving soil and the heave characteristics of the heaving soil generated at the actual site were quantitatively analyzed through DCM laboratory test construction. By reproducing a series of construction processes of the DCM method in a large-scale soil tank close to the actual site, the amount of heaving soil was predicted and the elevation characteristics such as elevation, diffusion range, diffusion angle and amount of elevation of the heaving soil were evaluated. As a result of the laboratory test construction, the actual elevation in terms of similarity within the DCM improvement section is 0~8.18m, and an average of 3.50m is observed. The actual diffusion range of the heaving soil converted to the similarity ratio is distributed from 28.0 to 38.0m on the left and right sides of the improvement section. The total amount of heaving soil calculated by the SUFFER program based on the results of the laboratory test construction is 19,901m³. Compared with the injected slurry amount of 16,992m³, the amount of heave compared to the injected amount is analyzed as 85.4%. The diffusion angle of DCM heaving soil, which analyzed the results of DCM laboratory test construction with the SUFFER program, is measured to be 30.0~38.0° at a depth of 50.0m, and is evaluated as an average of 34.0°. On the other hand, based on the DCM laboratory test construction and the analysis results using the program performed in this study, the amount of heaving soil at the DCM depths of 40.0m and 60.0m is predicted.

• Korean Journal of Culture and Social Issue
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• v.22 no.4
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• pp.675-693
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• 2016

As North Korean Youths are getting bigger, many psychologists have focused on them academically. But earlier studies showed many mistakes which have to be solved quickly. So the purposes of the present study are to set as the main problems as follows: Key issues and research direction for the Young North Korean defectors as research participants, issues and research direction for the objectivity of the Young North Korean defectors' psychological states, issues and research direction for the Young North Korea defectors' life in South Korea. Results as follows; First, there is no enough understanding of the research subjects and no consistency among the research results, and second, most of the researchers have no objective understanding of the research subjects' psychological states, and finally, most of the researchers have a 'adaptation model' strongly. So we have to have a more proper and objective stance for the Young North Korea defectors' life in South Korea.

• Journal of the Korean GEO-environmental Society
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• v.24 no.1
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• pp.5-14
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• 2023

In this study, the load transfer characteristics of the base and skin of drilled shafts were analyzed and the load sharing ratio was calculated by performing a load transfer large-scale model test and three-dimensional numerical analysis considering the similarity of drilled shafts, which is the design target. From the linear behavior of drilled shafts shown in the large-scale model test and 3D numerical analysis results, the skin load transition curve for the design conditions of this study was proposed by Baquelin et al., and the base load transition curve was proposed by Baquelin et al. For the horizontal load transition curve, the formula proposed by Reese et al. was confirmed to be appropriate. The test value was slightly larger than the numerical analysis value for the axial load at the rock socketing, but the load sharing ratio at the rock socketing increased, on average, about 27.8% as the vertical load increased. The analysis value of the vertical settlement of the pile head under the vertical load was evaluated to be slightly smaller than the test value, and the maximum vertical settlement of the pile head in the model test and analysis maximum vertical load was 10.6 mm in the test value and 10.0 mm in the analysis value, and the maximum vertical settlement value at the base of the pile was found to be a test value of 2.0 mm and an analysis value of 1.9 mm. The horizontal displacement at the head of the column (ground surface) and the head of the pile during the horizontal load was found to agree relatively well with the test value and the analysis value. As a result of the model soil test, the horizontal load measured at the maximum horizontal displacement of 38.0 mm was evaluated to be 24,713 kN, and the horizontal load in the numerical analysis was evaluated to be 26,073 kN.