• Journal of Korea Water Resources Association
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• v.48 no.9
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• pp.757-768
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• 2015

Recently, climate change has affected short time concentrated local rainfall and unexpected heavy rain which is increasingly causing life and property damage. In this research, arithmetic average analysis, weighted average analysis, and principal component analysis are used for predicting flood risk. This research is foundation for application of predicting flood risk based on annals of disaster and status of urban planning. Results obtained by arithmetic average analysis, weighted average analysis, and principal component analysis using many factors affect on flood are compared. In case of arithmetic average analysis, each factor has same weights though it is simple method. In case of weighted average analysis, correlation factors are complex by many variables and multicollinearty problem happen though it has different weights. For solving these problems, principal component analysis (PCA) is used because each factor has different weights and the number of variables is smaller than other methods by combining variables. Finally, flood risk assessment considering flood control ability and urban environment risk in former research is predicted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.543-548
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• 2017

This paper examines the effects of strong corporate governance for listed companies in accessing capital markets from the point of view of the weighted average cost of capital. Results found that corporate governance had a significant negative(-) relation to the weighted average cost of capital. This finding is consistent with previous research and implies that the higher shareholder ownership and foreign ownership have confidence in the financial information of the company, and therefore, risk is reduced for investors. This results in lower expected rates of return and companies will pay a lower cost of capital. Second, tax evasion had a positive effect(+) on the weighted average cost of capital. The low quality of corporate accounting information is expected to increase tax avoidance. Accordingly, this results in increased risk. If the required rate of return is high in its impact,it leads to increased capital costs. In addition, corporate governance and tax avoidance factors showed a negative affect (-) on the weighted average cost of capital. Corporate governance plays an important role in tax avoidance and the weighted average cost of capital, and strong corporate governance reducesthe impact on tax avoidance. In addition, the weighted average cost of capital in capital markets showed the reducing effect.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.503-510
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• 2016

The paper suggests to measure the risk of pedestrians inside urban railway stations. The level of risk is calculated in manner of both an average risk and average weighted risk of 9 different facility inside urban railway stations. Based on these level of risk, top 10 stations are chosen out of all the stations operated by Seoul Metro and Seoul Metropolitan Rapid Transit Cooperation (SMRT). In order to alleviate the level of risk, countermeasures for those risks are surveyed for 60 experts who are now involved in safety issues in those 2 railway operation companies. A countermeasure survey for the accidents is done into 2 ways. One is to lower the probability of making accidents and the other is to alleviate the consequence for accidents. The effectiveness of those alternatives is surveyed between 1 to 5 yardsticks and converted into one value for each alternative.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1065-1074
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• 2011

During several decades, many researchers in the field of finance have studied Value at Risk (VaR) to measure the market risk. VaR indicates the worst loss over a target horizon such that there is a low, pre-specified probability that the actual loss will be larger (Jorion, 2006, p.106). In this paper, we compare conditional copula method with two conventional VaR forecasting methods based on simple moving average and exponentially weighted moving average for measuring the risk of the portfolio, consisting of two domestic stock indices. Through real data analysis, we conclude that the conditional copula method can improve the accuracy of portfolio VaR forecasting in the presence of high kurtosis and strong correlation in the data.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.73-82
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• 2013

The main objective of this study was to evaluate Representative Concentration Pathways (RCP) scenarios-based flood risk at a Si-Gun level. A bias correction using a quantile mapping method with the Generalized Extreme Value (GEV) distribution was performed to correct future precipitation data provided by the Korea Meteorological Administration (KMA). A series of proxy variables including CN80 (Number of days over 80 mm) and CX3h (Maximum precipitation during 3-hr) etc. were used to carry out flood risk assessment. Indicators were normalized by a Z-score method and weighted by factors estimated by principal component analysis (PCA). Flood risk evaluation was conducted for the four different time periods, i.e. 1990s, 2025s, 2055s, and 2085s, which correspond to 1976~2005, 2011~2040, 2041~2070, and 2071~2100. The average flood risk indices based on RCP4.5 scenario were 0.08, 0.16, 0.22, and 0.13 for the corresponding periods in the order of time, which increased steadily up to 2055s period and decreased. The average indices based on RCP8.5 scenario were 0.08, 0.23, 0.11, and 0.21, which decreased in the 2055s period and then increased again. Considering the average index during entire period of the future, RCP8.5 scenario resulted in greater risk than RCP4.5 scenario.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.12a
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• pp.74-74
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• 2004

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.147-153
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• 2017

The mortality rate in industrial accidents in South Korea was 11 per 100,000 workers in 2015. It's five times higher than the OECD average. Economic losses due to industrial accidents continue to grow, reaching 19 trillion won much more than natural disaster losses equivalent to 1.1 trillion won. It requires fundamental changes according to industrial safety management. In this study, We classified the risk of accidents in industrial complex of Ulju-gun using spatial analytics and data mining. We collected 119 data on accident data, factory characteristics data, company information such as sales amount, capital stock, building information, weather information, official land price, etc. Through the pre-processing and data convergence process, the analysis dataset was constructed. Then we conducted geographically weighted regression with spatial factors affecting fire incidents and calculated the risk of fire accidents with analytical model for combining Boosting and CART (Classification and Regression Tree). We drew the main factors that affect the fire accident. The drawn main factors are deterioration of buildings, capital stock, employee number, officially assessed land price and height of building. Finally the predicted accident rates were divided into four class (risk category-alert, hazard, caution, and attention) with Jenks Natural Breaks Classification. It is divided by seeking to minimize each class's average deviation from the class mean, while maximizing each class's deviation from the means of the other groups. As the analysis results were also visualized on maps, the danger zone can be intuitively checked. It is judged to be available in different policy decisions for different types, such as those used by different types of risk ratings.

• Journal of Digital Convergence
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• v.3 no.1
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• pp.115-148
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• 2005

This study is intended to suggest a more reasonable and practical method of estimating discount & capitalization rate for valuation of closely-held culture content business, that is, to modify the Buildup Summation Model(which is recommended for the closely-held business by the NACVA) by adopting the weighted ratings in the CT Project Investment Evaluation of the Korea Culture Contents Association to risk factors of the Buildup Summation Model. This method is ease to apply for closely-held culture content business and has advantages in applying the weighted rates based on the characteristics of respective culture contents. And it can make up for the Weighted Average Cost of Capital (WACC) which shows generally low discount rates.

• Journal of Navigation and Port Research
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• v.31 no.2
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• pp.151-157
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• 2007

After World Trade Center's Terror in 2001 and promulgating Maritime Transportation Security Act (MTSA, 2002) and Security and Accountability For Every Port Act (SAFE Port Act, 2006) in the United States, most of the attention on security of international transportation including marine carrier and facility has focused increasingly. Inspection stations in foreign seaport terminal including Busan, South Korea, have been installed by Container Security Initiative (CSI) and Customs Trade Partnership against Terrorism (C-TPAT). The inspection station, however, may directly and indirectly affect delay of truck turnaround time in the seaport, especially high and severe level of security. This paper was analysed a risk for the additional average delay of truck turnaround time incurring by the inspection station under the all level of security, C-TPAT and CSI. As a result of this risk analysis, the higher weighted inspection time based on raising security level, the less number of trucks to be inspected, which will derive high delay in the inspection station.

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.681-691
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• 1994

The American Conference of Governmental Industrial Hygienists (ACGIH) has proposed a threshold limit value (TLV) for benzene of 0.1 ppm. Individuals representing the American Petroleum Institute (API)and the Chemical Manufacturers Association (CMA) have argued that 1) the risk assessment by Rinsky .et al. which ACGIH partially relied upon for its proposed TLV overestimates the risk; however, at the exposures levels of interest - (e.g., 0.1 to 1.0 ppm) for establishing a benzene TLV, the Rinsky et al. assessment provides lower estimates of leukemia risk than most others; 2) ACGIH should not use the Dow study for direct observational evidence of leukemia risk associated with low-level benzene exposure because of confounding exposure; however, it is unlikely that confounding exposures played a role in the excess of leukemia demonstrated in the study, and the Dow cohort was exposed to an average benzene concentration of about 5.5 ppm benzene for 7.11 years (31:1.5 ppm-years), while some of the individuals in the study who died from leukemia were exposed to an average of only 1.0 ppm without the opportunity for highpeak exposures; 3) the Occupational Safety and Health Administration (OSHA) established an 8-hour time-weighted average (TWA) of 1.0 ppm in 1987, and there is no new evidence that would justify reducing the TWA below that level; however, the OSHA TWA of 1.0 ppm was based on economic feasibility and the level of excess risk remaining at 1.0 ppm, i.e., 10 excess leukemia deaths per 1000 workers over an occupational lifetime (45 years) according to OSHA's preferred estimate leaves behind I risk considered significant by OSHA. In addition, chromosomal studies among workers and in animals exposed to benzene indicate that low-level exposure, i.e., 1.0 ppm, is associated with elevated Cytogenetic damage. On the basis of adverse health effects data alone, in this author's opinion, it would be poor science and poor public health policy to establish a benzene TLV greater than 0.1 ppm.