• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.187-200
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• 2013

In this paper, we deal with the problem of deciding a hedging volatility for ATM plain options when we hedge those options based on geometric Brownian motion. For this, we study the relation between hedging volatility and hedge profit&loss(P&L) as well as perform Monte Carlo simulations and real data analysis to examine how differently hedge P&L is affected by the selection of hedging volatility. In conclusion, using a relatively low hedging volatility is found to be more favorable for hedge P&L when underlying asset prices are expected to be range bound; however, a relatively high volatility is found to be favorable when underlying asset prices are expected to move on a trend.

• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.34-40
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• 2014

Since the global economic crisis in year 2008, the world civil helicopter market has been growing recently. According to the market outlook in the next decade, the demand of civil helicopter will be driven by the demand of Private & Corporate, Oil & Gas, Off-shore and EMS(Emergency Medical Service) usages. On the other side, the demand of military market will be driven by the modification and upgrading for life extension or performance enhancement than the new helicopter development for replacing old models. To summarize these situations, the demand of MRO(Maintenance, Repair & Overhaul) market has also been on the rise because of the demand due to above several usages in civil side and the life-extension in military side. Through the MRO market analysis for characteristics, developmental trends and a supply chain, this paper describes that the potential of MRO business is considerably large as a propulsive power of domestic helicopter industry. And also, it proposes the construction direction of MRO network because the domestic industry must make the developmental awareness and reliability a stepping-stone towards own helicopter.

• The Journal of Pediatrics of Korean Medicine
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• v.32 no.4
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• pp.141-162
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• 2018

Objectives The purpose of this study is to provide evidence of traditional Korean medicine treatment in children and adolescents by reviewing previous studies published in the journal of pediatrics of Korean medicine. Methods We have reviewed clinical studies of children and adolescents in the journal of pediatrics of Korean medicine from 2008 to 2017. Results Eighty-seven clinical studies of children and adolescents were reviewed. Total number of patients were 1644 in the studies. Among these, top 5 most commonly reported diseases in children and adolescents were atopic dermatitis, growth, autism, juvenile idiopathic arthritis and obesity. The most common intervention to treat those was taking herbal medicine. Most of the clinical studies showed effectiveness of this approach in treating children and adolescents. Conclusions More double-blinded randomized controlled clinical trials of Korean medicine interventions treating children and adolescents are needed to establish evidence-based treatment.

• Korean Journal of Metals and Materials
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• v.47 no.11
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• pp.699-706
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• 2009

Deformation behavior of pure aluminum during equal channel angular pressing (ECAP) was simulated using a three-dimensional version of the finite element method in conjunction with a constitutive model based on the dislocation density and cell evolution. The three-dimensional finite element analyses for the prediction of microstructural features, such as the variation of the dislocation density and the cell size with the number of ECAP, are reported. The calculated stress and strain and their distributions are also investigated for the route Bc ECAP processed pure aluminum. The results of finite element analyses are found to be in good agreement with experimental results for the dislocation cell size. Due to the accumulation of strain throughout the workpiece and an overall trend to saturation in cell size, a decrease of the difference in cell size with the number of passes (1~4) was predicted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.455-460
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• 2020

The governments of Korea, China, and Japan have operated comprehensive research institutes for railway technologies. Korea Railroad Research Institute (KRRI), China Academy of Railway Sciences Corporation Limited (CARS), and Railway Technical Research Institute (RTRI) are representatives of comprehensive railway research institutes in each country. KRRI was found to be the most advanced in the quantitative competitiveness of patents. In terms of qualitative competitiveness, KRRI has strength in civil engineering, whereas RTRI has strength in electricity. KRRI was found to have the greatest efforts in securing competitiveness in overseas property rights. By comparing the publication of papers, CARS published the most papers. On the other hand, from 2015, KRRI showed an upward trend and published the most papers. By examining the impact of the papers by the citation, KRRI was found to have higher competitiveness than the other two institutions. In the future, it will be necessary to perform big data analysis on patents and papers of the three organizations, derive the key research areas and promising technology areas for each institute, and establish a mid-to-long-term development plan for railway technology based on scientific evidence.

• Journal of Cadastre & Land InformatiX
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• v.49 no.2
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• pp.67-82
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• 2019

The purpose of this study is to analyze the issues and perceptions of smart cities. First, based on the big data analysis platform, big data analysis on smart cities were conducted to derive keywords by year, word cloud, and frequency of generation of smart city keywords by time. Second, trend and flow by area were analyzed by reclassifying major keywords by year based on meta-keywords. Third, emotional recognition flow for smart cities and major emotional keywords were derived. While U-City in the past is mostly centered on creating infrastructure for new towns, recent smart cities are focusing on sustainable urban construction led by citizens, according to the analysis. In addition, it was analyzed that while infrastructure, service, and technology were emphasized in the past, management and methodology were emphasized recently, and positive perception of smart cities was growing. The study could be used as basic data for the past, present and future of smart cities in Korea at a time when smart city services are being built across the country.

• Journal of Korea Water Resources Association
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• v.53 no.spc1
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• pp.743-753
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• 2020

In this study, research trends in the water resources in Korea were analyzed to present regional customization and optimal operation management of groundwater resources. Detailed classification fields were determined in the water and groundwater resources. Through the analysis of examples and trends of research related to water resources and underground water resources, three improvements were presented: securing sites for long-term observable research area, evaluating water resources based on spatial units, and not reflecting the characteristics of watersheds in acts and ordinances. The research results of this study are expected to be the basis for policy judgment in determining the groundwater management policy after the group of groundwater management policy makers at the research site can identify the requirements.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.119-131
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• 2007

Design build (DB) is a construction project delivery system which has become one of the favored ones and the growth of DB by the public agencies has been steadily increasing. DB can be viewed as an evolutionary project delivery system, since DB project team members collaborate on work with each other, keep seeking cost effective and innovative alternatives that meet the construction needs of the project. Thus DB outperformed others in delivery speed, cost saving, and turnover quality. In Korea, DB projects likewise have steadily increased that it is needed to analyze characteristics of DB delivery system in Korea. For that purpose, this research would offer an analysis of characteristics of DB delivery system in Korea using system dynamics model with investigating the public market trend, comparing DB performance to DBB, and analyzing questionnaire survey.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.21-29
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• 2020

The Topic Modeling research, the methodology for deduction keyword within literature, has become active with the explosion of data from digital society transition. The research objective is to investigate research trends in D.N.A.(Data, Network, Artificial Intelligence) field using DTM(Dynamic Topic Model). DTM model was applied to the 1,519 of research projects with SW·A.I technology classifications among ICT(Information and Communication Technology) field projects between 6 years(2015~2020). As a result, technology keyword for D.N.A. field; Big data, Cloud, Artificial Intelligence, extended keyword; Unstructured, Edge Computing, Learning, Recognition was appeared every year, and accordingly that the above technology is being researched inclusively from other projects can be inferred. Finally, it is expected that the result from this paper become useful for future policy·R&D planning and corporation's technology·marketing strategy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.74-79
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• 2016

The Seoul Metropolitan Subway, which started operating in 1974, plays a major role in transporting 7,289 thousands passengers daily. This trend of a steadily increase in passengers from 2012 has increased the congestion rate because of the limited capacity and time. To solve this problem, Seoul city is consistently working on improving the subway facilities, such as the construction of a detour path. This project, however, has only a slight effect on improving the congestion rate and is too expensive to construct the facilities. Hence, this study suggests The Congestion Standardization System based on the IoT for improving the subway congestion rate. Based on the system, the expected effect analysis was performed, which resulted in a decrease in ride passengers from 34 to 20. In addition, this expected effect analysis shows that the number of subway vehicles can increase from 20 to 24. The suggested system will have a significant effect on the efficiency of the management system.