• Asia-Pacific Journal of Atmospheric Sciences
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• v.54 no.4
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• pp.545-561
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• 2018

Over the North East Asia, extreme anomalous precipitation were observed in 2013 and 2014. During 2013 summer the precipitation was found to be higher (two standard deviation) than the climatological mean of the region; whereas during 2014, which was a borderline El Ni?o year, precipitation was found to be lower (one standard deviation). To understand the differences of these two anomalous years the Global/Regional Integrated Model system (GRIMs) has been used. The study found that low landsurface temperature and high sea-surface temperature over ocean caused a smaller land-sea contrast of surface temperature between East Asia and North West Pacific Ocean in 2014, which could have caused an eastward shift of mean monsoon circulation in that year compared to the circulation in 2013. Due to a change in the lower level circulation and wind field over East Asia the evaporation and moisture transport patterns became very different in those two years. In 2013, this study found high latent heat flux over Eastern China, which implies an increased surface evaporation over that region, and the moisture transported to the north by the mean monsoon circulation; whereas, there was no correlated transport of moisture to the North East Asia during 2014. The precipitable water over North East Asia has a stronger correlation with the latent heat flux over southern land region than that from Ocean region in the eastern side in both the years. A new approach is proposed to estimate the sub-grid scale hydrometeors from GRIMs, overestimated in the existing model.

• Informatization Policy
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• v.27 no.4
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• pp.47-66
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• 2020

The rapid development of artificial intelligence technologies such as machine learning and deep learning is expanding its impact in the public administrative and public policy sphere. This paper is an exploratory study on policy decision-making in the age of artificial intelligence to design automated configuration and operation through data analysis and algorithm development. The theoretical framework was composed of the types of policy problems according to the degree of problem structuring, and the success and failure cases were classified and analyzed to derive implications. In other words, when the problem structuring is more difficult than others, the greater the possibility of failure or side effects of decision-making using artificial intelligence. Also, concerns about the neutrality of the algorithm were presented. As a policy suggestion, a subcommittee was proposed in which experts in technical and social aspects play a professional role in establishing the AI promotion system in Korea. Although the subcommittee works independently, it suggests that it is necessary to establish governance in which the results of activities can be synthesized and integrated.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.29-45
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• 2022

This study aims to analyze how the public perceive the climate change in South Korea. The climate change has been highlighted due to its social and environmental impact on future society during decades. In recent, the outbreak of COVID-19 alerted the causal relationship between diseases and the climate change and forced decision-makers to cope with possible future epidemics. Along with the social and political importance of the climate change, the perception and actions of the public also become significant. Thus, this study analyzes the trends in the public perception of climate change before and after the COVID-19, using social media big data from March 1, 2019 through February 28, 2022. The results show that the negative perception dominated the public's perception, but a little positive perception implies that numerous policies on the climate change may help the public convert their negative perception to the positive. This study may help the decision-makers develop future policies and strategies on the climate change and carbon neutrality by considering the demand-side perception, such as South Korean perception.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.39-44
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• 2022

The advent, course, and possible consequences of the COVID-19 pandemic are now the focus of global attention. From whichever side the geopolitical centers of influence might view it, the problem of the coronavirus concerns all world leaders and the representatives of all branches of science, especially physicians, economists, and politicians - virtually the entire population of the planet. The uniqueness of the COVID-19 phenomenon lies in the uncertainty of the problem itself, the peculiarities and specifics of the course of the biological processes in modern conditions, as well as the sharp confrontation of the main political players on the world stage. Based on an analysis of scientific research, the article describes the profile of the emotional concept of "anxiety" in Russian linguoculture. Through monitoring the headlines of Russian media reports in the "COVID-19" section of Google News and Mail News news aggregators dated August 4-6, 2021, the study establishes the quantitative and qualitative characteristics of the alarm-generating news products on coronavirus in the Russian segment of the Internet and interprets the specifics of media information about COVID-19. The level of mass media criticism in Russia is determined through a phone survey. It is concluded that coronavirus reports in online media conceptualize anxiety about the SARS virus and the COVID-19 disease as a complex cognitive structure. The media abuse the trick of "magic numbers" and emotionally expressive words in news headlines, which are perceived by mass information consumers first and typically uncritically.

• Clinics in Shoulder and Elbow
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• v.26 no.4
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• pp.373-379
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• 2023

Background: The purpose of this study was to determine the association between smoking and clinical outcomes of hook plate fixation for acute acromioclavicular (AC) joint injuries. Methods: This study retrospectively investigated 82 patients who underwent hook plate fixation for acute AC joint dislocation between March 2014 to June 2022. The patients were grouped by smoking status, with 49 in group N (nonsmokers) and 33 in group S (smokers). Functional scores and active range of motion were compared among the groups at the 1-year follow-up. Coracoclavicular distance (CCD) was measured, and difference with the uninjured side was compared at initial injury and 6 months after implant removal. Results: No significant differences were observed between the two groups in demographic factors such as age and sex, as well as parameters related to initial injury status, which included time from injury to surgery, the preoperative CCD difference value, and the Rockwood classification. However, the postoperative CCD difference was significantly higher in group S (3.1±2.6 mm) compared to group N (1.7±2.4 mm). Multivariate regression analysis indicated that smoking and the preoperative CCD difference independently contributed to an increase in the postoperative CCD difference. Despite the radiographic differences, the postoperative clinical outcome scores and active range of motion measurements were comparable between the groups. Conclusions: Smoking had a detrimental impact on ligament healing after hook plate fixation for acute AC joint dislocations. This finding emphasizes the importance of smoking cessation to optimize reduction maintenance after AC joint injury. Level of evidence: III.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.19-29
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• 2012

We made a regression analysis on the early IPO of venture capital investments in Korean IPO market. First, we found that it was likely to shorten the period to IPO in companies which were fast growing with a good operating cash flow, but these companies had a higher possibility of the earning management. Second, companies with more assets and larger size of the board of directors did not take companies public any earlier. Third, a better corporate governance also had no impact on the time period to IPO in the newly public firms. The findings above clearly show that venture-backed companies in Korea pursue the tendency of an early IPO. This phenomenon was much clearer when the companies were invested in by multiple venture capital firms than by a single investor. In general, venture capital firms invest in companies which are fast growing and which have a good operating cash flow. On the other side, venture capitals make investee companies go public earlier by manipulating operating earnings, so that they themselves may exit early. In conclusion, this research has shown that venture capitals in Korea do not play a positive role in the corporate transparency. This is the paradox of venture capital investment and this also shows the current status of Korean venture capital firms.

• The Korean Journal of Applied Statistics
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• v.29 no.3
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• pp.409-424
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• 2016

This study analyzed the causal relationship among factors that influence the purchase intensions for individual pensions which have a growing importance as a financial means after retirement. For this purpose, structural equation modeling based on the survey data (N = 928) was conducted to analyze psychological factors and financial factors comprehensively. According to empirical results of the structural equation, in the case of non-subscribers of individual pensions, potential longevity and coping efficacy influenced the purchase intensions for individual pensions fully mediated by fear and worry about longevity. Trust in insurers and risk tolerance directly influenced the purchase intensions for individual pensions. These show that trust in insurers is the most important factor in purchase intensions for individual pensions. Also, only trust in insurers give a direct impact on individual pensions in the case of individual pension subscribers. Longevity-related emotional side is expected to help in marketing activities that target potential customers signing individual pensions. In addition, trust in insurers has the greatest impact on new and additional subscriptions that represent critical efforts to improve trust in insurers.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.57-65
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• 2022

This study simulated the shock wave propagation through the tamping material between explosives and hole wall at blasting works and verified the effect of tamping materials. The Arbitrary Lagrangian-Eulerian(ALE) method was selected to model the mixture of solid (Lagrangian) and fluid (Eulerian). The time series analysis was carried out during blasting process time. Explosives and tamping materials (air or water) were modeled with finite element mesh and the hole wall was assumed as a rigid body that can determine the propagation velocity and shock force hitting the hole wall from starting point (explosives). The numerical simulation results show that the propagation velocity and shock force in case of water were larger than those in case of air. In addition, the real site at blasting work was modeled and simulated. The rock was treated as elasto-plastic material. The results demonstrate that the instantaneous shock force was larger and the demolished block size was smaller in water than in air. On the contrary, the impact in the back side of explosives hole was smaller in water, because considerable amount of shock energy was used to demolish the rock, but the propagation of compression through solid becomes smaller due to the damping effect by rock demolition. Therefore, It can be proven that the water as the tamping media was more profitable than air.

• Information Systems Review
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• v.24 no.4
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• pp.41-54
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• 2022

Despite the recent rapid advancement of science and technology, we have been experiencing the decline in productivity since the 2000s. This study aims to investigate the decline at both industry and firm levels, by looking at the emergence and growth of large firms such as Amazon, Alphabet, and Apple and M&A trends. Following the results of previous studies, our results show that productivity at industry level has decreased since the 2000s. Particularly, in the period after 2011, the deterioration of allocative efficiency due to the large firms and the decline in the growth rate of surviving firms in the industry with low ratio of large firms contributed to the productivity decline. On the other hand, our analysis at firm level demonstrates that the productivity of firms that acquired IT firms improved over the entire period. While M&As have a positive impact on productivity, M&As with a demand-side motive such as market penetration and expansion of channels have a relatively larger impact than the ones for production or operation efficiency. Our results also suggest that the higher the proportion of large firms in a specific industry, the lower the productivity of individual firms in the same industry. Overall, given that the industry's structural changes for digital transformation tends to strengthen the growth of large firms, our findings have significant implications by empirically identifying the relationships of the emergence of large firms, the acquisition of IT/Non-IT firms, and motivations for M&As to firm/industry productivity.

• Tunnel and Underground Space
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• v.21 no.5
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• pp.394-405
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• 2011

In this paper, we applied coupled non-isothermal, multiphase fluid flow and geomechanical numerical modeling using TOUGH-FLAC coupled analysis to study the complex thermodynamic and geomechanical performance of underground lined rock caverns (LRC) for compressed air energy storage (CAES). Mechanical stress in concrete linings as well as pressure and temperature within a storage cavern were examined during initial and long-term operation of the storage cavern for CAES. Our geomechanical analysis showed that effective stresses could decrease due to air penetration pressure, and tangential tensile stress could develop in the linings as a result of the air pressure exerted on the inner surface of the lining, which would result in tensile fracturing. According to the simulation in which the tensile tangential stresses resulted in radial cracks, increment of linings' permeability and air leakage though the linings, tensile fracturing occurred at the top and at the side wall of the cavern, and the permeability could increase to $5.0{\times}10^{-13}m^2$ from initially prescribed $10{\times}10^{-20}m^2$. However, this air leakage was minor (about 0.02% of the daily air injection rate) and did not significantly impact the overall storage pressure that was kept constant thanks to sufficiently air tight surrounding rocks, which supports the validity of the concrete-lined underground caverns for CAES.