• Journal of Korea Port Economic Association
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• v.39 no.1
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• pp.115-129
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• 2023

This study analyzed the risk spillover of BDI on shipping company stock prices through the Copula-CoVaR method based on daily data from January 4, 2010, to October 31, 2022. The main empirical analysis results and policy implications are as follows. First, copula results showed that there was a weak dependence between BDI and shipping company stock prices, and PAN, KOR, and YEN were selected as the most fitting model for dynamic Student-t copula, HMM was selected as the rotated Gumbel copula, and KSS was selected as the best model. Second, in the results of CoVaR, it was confirmed that the upside (downside) CoVaR was significantly different from the upside (downside) VaR in all shipping companies. This means that BDI has a significant risk spillover on shipping companies. In addition, as for the risk spillover, the downside risk is generally lower than the upside risk, so the downside and upside risk spillover were found to be asymmetrical. Therefore, policymakers should strengthen external risk supervision and establish differentiated policies suitable for domestic conditions to prevent systematic risks from BDI shocks. And investors should reflect external risks from BDI fluctuations in their investment decisions and construct optimal investment portfolios to avoid risks. On the other hand, investors propose that the investment portfolio should be adjusted in consideration of the asymmetric characteristics of up and down risks when making investment decisions.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.223-242
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• 2023

This study analyzes the spillover effects of returns and volatility between the commodity market and the maritime freight market across various frequency domains (short-term, medium-term, long-term). The key findings of the study can be summarized as follows. First, from the perspective of returns, a high linkage is observed in the short-term between the commodity and maritime freight markets, with the metal commodities market playing a particularly significant role in information transmission effect of return series. Second, in terms of volatility, the total connectedness increases from the short- to the long-term, with substantial long-term risk transmission effects observed especially in the BDI, BDTI, agricultural, and energy commodity markets. Notably, during major global events such as the U.S.-China trade war, COVID-19, and the Russia-Ukraine conflicts, a marked increase in the risk transmission effect in the energy commodities market was identified.

• The Science & Technology
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• no.9 s.412
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• pp.9-11
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• 2003

은하계도 '약육강식' 장면 촬영 성공/ 아기들의 요람사 원인은 자궁으로 되돌아가는 꿈 때문/ 스트레스, 암세포 전이 촉진/ 녹차 항암효과, 생각보다 탁월/ 과학 · 의학 전공자가 예술 · 법학 전공자보다 장수/ "집안에서는 무조건 금연해야"/ 레이저 대신 태양광선으로 수술/ 넥타이 죄어 매면 녹내장 위험 증가/ 생각만으로 움직이는 휠체어 개발/ 크고 선명할수록 보기 어렵다/ 운동중 수분 과음하면 사망 위험

• Journal of Korea Port Economic Association
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• v.34 no.2
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• pp.31-50
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• 2018

This study implemented an empirical analysis of education and training for dangerous goods and hazardous materials handlers on the Busan New Port terminals and hinterland logistics centers using a Structural Equation Modeling (SEM) in combination with the formative model and reflective model, from the viewpoint of the supply chain. An effect size analysis was also conducted. The results of the empirical analysis show that Training Environment and the Atmosphere of Education have a positive influence on the Educational Expectation of hazardous material handlers, and the Educational Expectation has a positive influence on the Education and Training Program and Transfer of Education Training. Likewise, the Education and Training Program has a positive influence on the Transfer of Education Training and Result of Education and Training. Furthermore, the Transfer of Education Training has a positive influence on the Result of Education and Training. The Result of Education and Training has a positive influence on the Present State of hazardous material management. According to the results of the effect size analysis, the following parameters represented a great effect: the Atmosphere of Education to the Education Expectation, the Education Expectation to the Education and Training Program, the Transfer of Education Training to the Result of Education and Training, and the Result of Education and Training to the Present State of Dangerous Goods Management. The results of this study provided various suggestions for related practices.

• Journal of Convergence for Information Technology
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• v.10 no.4
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• pp.46-54
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• 2020

This study aims to develop and analyze the performance of a selective option straddle strategy based on forecasted volatility to improve the weakness of typical straddle strategy solely based on negative volatility risk premium. The KOSPI 200 option volatility is forecasted by the SVM model combined with the asymmetric volatility spillover effect. The selective straddle strategy enters option position only when the volatility is forecasted downwardly or sideways. The SVM model is trained for 2008-2014 training period and applied for 2015-2018 testing period. The suggested model showed improved performance, that is, its profit becomes higher and risk becomes lower than the benchmark strategies, and consequently typical performance index, Sharpe Ratio, increases. The suggested model gives option traders guidelines as to when they enter option position.

• Korean journal of communication and information
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• v.72
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• pp.52-91
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• 2015

The purpose of this study is to examine the effects of attribute agenda-setting and priming through content analysis and a survey about Particulate Matter($PM_{10}$ & $PM_{2.5}$) using both promotional news and general news. The study results were as follows. First, promotional news and general news were found to showcase similar cognitive attributes. Second, the results did not show a significant relationship between highlighted attributes in media coverage and the public's salient attributes, but media attributes had been generally reflected in the public's perception because the public was highly aware of the importance of all media attributes. Third, the recognition of the public's attribute importance affected the direction of public opinion, which resulted in the acceptance of priming effects. Meanwhile, the recognition of the public's attribute importance towards economic damage, international cooperation, individual response, and the recognition of promotional news had affected risk perception. Furthermore, the recognition of promotional news and involvement appeared to have an interaction effect on risk perception.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.963-964
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• 2010

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.49-59
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• 2012

Recently, various alternatives for safety and efficiency of commercial vehicles have been considered, and one of the new alternatives is the application of a digital tachograph. In Korea, the installation of a digital tachograph to commercial vehicles was regulated from 2011 and Korea Transportation Safety Authority developed e-TAS to analyze the monitoring data from digital tachographs installed in the order of 100 commercial vehicles. This study performs the potential impact analysis of the DTG installation, which includes a trend of dangerous driving, a trend of traffic accidents and cost-effective analysis, a trend of fuel consumption and cost-effective analysis, a cost-effective analysis of social benefits using e-TAS data. Depending on the frequency of dangerous driving, the participants are divided into three groups; high-dangerous group, average-dangerous group and low-dangerous group. The high-dangerous driving group shows lower km/liter than the low-dangerous driving group by 15% for buses and taxis and by 30% for trucks. About $CO_2$ emission, the difference becomes bigger; 25%, 25% and 42% for buses, taxis and trucks, respectively. Although this study is a short-term period analysis, the methodology will be applicable for the long-term period analysis with larger data.

• 한국벤처창업학회:학술대회논문집
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• 2016.04a
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• pp.166-168
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• 2016

본 연구는 인터넷 접속 환경이 유선에서 무선으로 급속히 전환되고 인터넷에 접속할 수 있는 시간과 공간의 제약이 없어지면서 인터넷 중독자 문제가 많은 사회문제를 야기하고 있는 시점에서 인터넷 중독자수 예측 및 중독자 치료 프로그램의 효과를 분석하기 위한 연구이다. 청소년을 대상으로 통계청 추정인구와 공공분문의 통계자료를 바탕으로 중독자 예측 및 회복효과 측정 프로그램을 개발하여 분석하였다. 연구결과 스마트기기의 보급의 확대의 영향으로 청소년 인터넷 중독자 수는 점차 증가하다가 청소년 인구감소의 영향으로 2016년을 기점으로 감소하는 것으로 분석되었다. 중독예방과 치료를 위한 예산 증가 시나리오 분석 결과 인터넷 중독 잠재적 위험과 고위험군에서 모두 효과가 있는 것으로 분석되었고 중독 다음 단계로 전이 되는 것을 예방하는 효과가 있는 것으로 나타났다. 특히 인터넷 중독 고위험 사용자의 전문치료 수준을 강화했을 경우 그 효과가 큰 것으로 나타났다.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.119-133
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• 2020

Fama asserted that in an efficient market, we can't make a trading rule that consistently outperforms the average stock market returns. This study aims to suggest a machine learning algorithm to improve the trading performance of an intraday short volatility strategy applying asymmetric volatility spillover effect, and analyze its trading performance improvement. Generally stock market volatility has a negative relation with stock market return and the Korean stock market volatility is influenced by the US stock market volatility. This volatility spillover effect is asymmetric. The asymmetric volatility spillover effect refers to the phenomenon that the US stock market volatility up and down differently influence the next day's volatility of the Korean stock market. We collected the S&P 500 index, VIX, KOSPI 200 index, and V-KOSPI 200 from 2008 to 2018. We found the negative relation between the S&P 500 and VIX, and the KOSPI 200 and V-KOSPI 200. We also documented the strong volatility spillover effect from the VIX to the V-KOSPI 200. Interestingly, the asymmetric volatility spillover was also found. Whereas the VIX up is fully reflected in the opening volatility of the V-KOSPI 200, the VIX down influences partially in the opening volatility and its influence lasts to the Korean market close. If the stock market is efficient, there is no reason why there exists the asymmetric volatility spillover effect. It is a counter example of the efficient market hypothesis. To utilize this type of anomalous volatility spillover pattern, we analyzed the intraday volatility selling strategy. This strategy sells short the Korean volatility market in the morning after the US stock market volatility closes down and takes no position in the volatility market after the VIX closes up. It produced profit every year between 2008 and 2018 and the percent profitable is 68%. The trading performance showed the higher average annual return of 129% relative to the benchmark average annual return of 33%. The maximum draw down, MDD, is -41%, which is lower than that of benchmark -101%. The Sharpe ratio 0.32 of SVS strategy is much greater than the Sharpe ratio 0.08 of the Benchmark strategy. The Sharpe ratio simultaneously considers return and risk and is calculated as return divided by risk. Therefore, high Sharpe ratio means high performance when comparing different strategies with different risk and return structure. Real world trading gives rise to the trading costs including brokerage cost and slippage cost. When the trading cost is considered, the performance difference between 76% and -10% average annual returns becomes clear. To improve the performance of the suggested volatility trading strategy, we used the well-known SVM algorithm. Input variables include the VIX close to close return at day t-1, the VIX open to close return at day t-1, the VK open return at day t, and output is the up and down classification of the VK open to close return at day t. The training period is from 2008 to 2014 and the testing period is from 2015 to 2018. The kernel functions are linear function, radial basis function, and polynomial function. We suggested the modified-short volatility strategy that sells the VK in the morning when the SVM output is Down and takes no position when the SVM output is Up. The trading performance was remarkably improved. The 5-year testing period trading results of the m-SVS strategy showed very high profit and low risk relative to the benchmark SVS strategy. The annual return of the m-SVS strategy is 123% and it is higher than that of SVS strategy. The risk factor, MDD, was also significantly improved from -41% to -29%.