• 대한수학회논문집
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• 제23권1호
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• pp.141-151
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• 2008

In this paper, we derive the nonlinear equation for European option pricing containing liquidity risk which can be defined as the inverse of the partial derivative of the underlying asset price with respect to the amount of assets traded in the efficient market. Numerical solutions are obtained by using finite element method and compared with option prices of KOSPI200 Stock Index. These prices computed with liquidity risk are considered more realistic than the prices of Black-Scholes model without liquidity risk.

• 아태비즈니스연구
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• 제12권1호
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• pp.135-149
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• 2021

Purpose - I analyzes risk-to-performance evaluated in the market using data from sale and lease back. Specifically, I analyze from the perspective of financial institutions that purchase sale and lease back based on the cases of investment by ship investment companies and acquisition of ships. Design/methodology/approach - I use 49 sale and lease back data from 2017 to 2019 for empirical analysis. Findings - The main results of this paper are as follows. First, after sale and lease back of domestic ships, the average amount of sales by the leased shipping company is 25.1 billion won, the average amount of investment by the purchased financial institution is 14.6 billion won (60%) and the average length of the ship is nine years. In ship finance, sale and lease back is deemed to be appropriately used as a means of restructuring for a large amount of money. Second, the main risk factor for sale and lease back of domestic ships is credit risk and can be measured in VaR in practice. As a result of the empirical analysis, the average credit risk burden ratio is 9%. As a major risk factor, low creditworthiness of restructuring companies is the key. Third, as a result of measuring the profitability of financial institutions that purchase sale and lease back of domestic ships at a net current price, it has an average value of 300 million won, but the deviation by case is very large. Fourth, the risk adjusted performance of sale and lease back of domestic ships is 0.54 on average compared to the total risk capital, and 0.52 compared to the stock-risk capital, and as with profitability earlier, the deviation of each case is very large and misaligned. In order to boost the sale and lease back market for large and long-term assets, in order to overcome low profitability as a prerequisite for future participation of commercial purchased financial institutions, it is expected that purchase decisions based on expectations versus risk will be necessary. Research implications or Originality - The results of this paper are expected to broaden the understanding of sale and lease back and foster the ability to assess long-term risk and performance. Based on this, it is believed that rapid restructuring of companies through sale and lease back of large amounts of long-term assets will greatly increase the utility of the domestic financial market.

• Journal of Preventive Medicine and Public Health
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• 제35권3호
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• pp.255-262
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• 2002

Objectives : To investigate the fetal cholesterol levels and related factors in a rural adult population. Methods : 3,207 adults(1,272 men and 1,935 women) were examined in 1997 Their heights, weights, and fasting serum total cholesterol levels were measured, and their body mass indices were calculated. A questionnaire interviewing method was used to collect risk factor data. Results : The mean value of total cholesterol were 190.5 mg/dl, and 198.8 mg/dl, and the age-adjusted prevalence rates for hypercholesterolemia (above 240 mg/dl) were 13.7% and 10.2%, in men and women, respectively. From simple analyses, age, educational level, coffee intake, amount of meat and food intake, waist circumference, waist-hip circumference ratio(WHR), and body mass index(BMI) were significant risk factors in men (p<0.05) relating to serum total cholesterol levels. In women, age, educational level, hypertension history, diabetes history, herbal drug history, amount of feed intake, alcohol consumption, waist circumference, WHR, BMI, and menopausal status were significant risk factors (p<0.05). In multiple linear regression analyses, waist circumference (p<0.01), BMI (p<0.01), and coffee intake (p<0.05) proved to be significant risk factors in men. Whereas, menopausal status (p<0.01), BMI (p<0.01), herbal drug history (p<0.01), amount of food intake (p<0.05), waist circumference (p<0.05), and alcohol consumption (p<0.05) were significant risk factors in women. Conclusions : The significant risk factors, for both men and women, relating to the serum total cholesterol were waist circumference and BMI. Thus, for the reduction of serum total cholesterol level, it is recommended that health education for the control of obesity should be implemented.

• 한국안전학회지
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• 제14권4호
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• pp.120-125
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• 1999

This study evaluated the effect of the accidents caused by fire, explosion, and toxic gas release by using SuperChems, quantitative hazardous material release modeling software, which estimates the potential area of damage. According to the loss severity, the appropriate risk management principles can be applied. Risk management is divided into the two methods which are risk control and risk financing. Risk control includes risk avoidance, risk spreading and diversification, and risk reduction. Risk financing includes risk retention and risk transfer. The results of this study can help the related company determine the appropriate reserve fund and the amount to be insured against the third party losses according to the estimated loss severity.

• The Plant Pathology Journal
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• 제28권2호
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• pp.172-184
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• 2012

An infection risk model for Phytophthora blight on chili pepper was developed to estimate the first date of disease occurrence in the field. The model consisted of three parts including estimation of zoosporangium formation, soil water content, and amount of active inoculum in soil. Daily weather data on air temperature, relative humidity and rainfall, and the soil texture data of local areas were used to estimate infection risk level that was quantified as the accumulated amount of active inoculum during the prior three days. Based on the analysis on 190 sets of weather and disease data, it was found that the threshold infection risk of 224 could be an appropriate criterion for determining the primary infection date. The 95% confidence interval for the difference between the estimated date of primary infection and the observed date of first disease occurrence was $8{\pm}3$ days. In the model validation tests, the observed dates of first disease occurrence were within the 95% confidence intervals of the estimated dates in the five out of six cases. The sensitivity analyses suggested that the model was more responsive to temperature and soil texture than relative humidity, rainfall, and transplanting date. The infection risk model could be implemented in practice to control Phytophthora blight in chili pepper fields.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2021년도 제64차 하계학술대회논문집 29권2호
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• pp.41-44
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• 2021

In this paper, we propose a monitoring system that can monitor gas leakage concentrations in real time and forecast the amount of gas leaked after one minute. When gas leaks happen, they typically lead to accidents such as poisoning, explosion, and fire, so a monitoring system is needed to reduce such occurrences. Previous research has mainly been focused on analyzing explosion characteristics based on gas types, or on warning systems that sound an alarm when a gas leak occurs in industrial areas. However, there are no studies on creating systems that utilize specific gas explosion characteristic analysis or empirical urban gas data. This research establishes a deep learning model that predicts the gas explosion risk level over time, based on the gas data collected in real time. In order to determine the relative risk level of a gas leak, the gas risk level was divided into five levels based on the lower explosion limit. The monitoring platform displays the current risk level, the predicted risk level, and the amount of gas leaked. It is expected that the development of this system will become a starting point for a monitoring system that can be deployed in urban areas.

• Safety and Health at Work
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• 제7권3호
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• pp.251-255
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• 2016

Background: Building demolition can lead to emission of dust into the environment. Exposure to silica dust may be considered as an important hazard in these sites. The objectives of this research were to determine the amount of workers' exposure to crystalline silica dust and assess the relative risk of silicosis and the excess lifetime risk of mortality from lung cancer in demolition workers. Methods: Four sites in the Tehran megacity region were selected. Silica dust was collected using the National Institute for Occupational Safety and Health method 7601 and determined spectrophotometrically. The Mannetje et al and Rice et al models were chosen to examine the rate of silicosis-related mortality and the excess lifetime risk of mortality from lung cancer, respectively. Results: The amount of demolition workers' exposure was in the range of $0.085-0.185mg/m^3$. The range of relative risk of silicosis related mortality was increased from 1 in the workers with the lowest exposure level to 22.64/1,000 in the employees with high exposure level. The range of the excess lifetime risk of mortality from lung cancer was in the range of 32-60/1,000 exposed workers. Conclusion: Geometric and arithmetic mean of exposure was higher than threshold limit value for silica dust in all demolition sites. The risk of silicosis mortality for many demolition workers was higher than 1/1,000 (unacceptable level of risk). Estimating the lifetime lung cancer mortality showed a higher risk of mortality from lung cancer in building demolition workers.

• 한국건설관리학회논문집
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• 제4권1호
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• pp.122-130
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• 2003

최근 건설공사가 대형화$\cdot$특수화$\cdot$다양화됨에 따라 시공 중에 돌발적인 사고의 발생 가능성이 높아지고 있으며, 사고발생 시에는 막대한 경제적 손실과 인적피해를 수반하여 그 사회적 충격도 커지고 있다. 이러한 우연한 사고의 발생으로 인한 손실에 대비하여 일부 공공공사에 대하여 의무적으로 건설공사보험(Contractor's all risks insurance policy : CAR, 이하 공사보험)에 가입하도록 관련법에서 규정하고 있다. 이처럼 공사보험이 위험관리의 주요 수단으로 활용되고 있으나, 공사보험요율의 적정성 및 공평성에 대하여 많은 문제가 제기되고 있다 이에 본 연구에서는 첫째, 보험요율의 적정성을 검토하고 수급자의 공사수행 위험도를 평가하여 공사보험요율에 반영할 수 있는 할인$\cdot$할증 제도의 적용방안을 제시하고 둘째 이 제도를 적용하기 위해 수급자의 공사수행 위험도를 평가하기 위한 항목의 개발방향을 제시하였다. 마지막으로 공사위험의 특성을 고려하여 보험요율 결정과정을 합리적으로 진행하기 위해 건설공사와 관련된 기술전문가와 보험관련 전문가로 구성된 위험평가 팀의 활용방안에 대하여 제시하였다.

• 융합정보논문지
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• 제12권4호
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• pp.111-118
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• 2022

본 연구는 감사위험에 대한 감사인의 반응에 대해 분석한 논문이다. 구체적으로 감사위험은 당기 재무제표의 수정금액으로 측정하였고, 감사인의 반응은 차기 감사시간의 증감률로 측정하였다. 회사의 재무제표 작성능력이 부족하거나 이익조정 금액이 클수록 감사인의 수정금액도 커질 것이기 때문에 수정금액을 감사인이 인식한 회사의 감사위험으로 볼 수 있으며, 감사인은 감사계획 시 감사위험을 고려할 것이기 때문에 차기 감사시간의 증감률로 감사인의 반응을 측정하였다. 한편 감사위험에 대한 감사인의 반응은 직급에 따라 다를 것이다. 회계감사는 품질관리검토자, 업무수행이사, 그리고 등록공인회계사 등이 팀을 이뤄 수행하지만 감사계획을 수립하고 감사품질을 관리하는 감사인이 현장에서 감사실무를 수행하는 감사인보다 감사위험에 대해 보다 민감하게 반응할 것으로 예상된다. 분석결과, 당기 재무제표의 수정금액이 일정수준 이상으로 크면 감사인은 이를 유의한 감사위험으로 인식하여 차기의 감사투입시간을 증가시키며, 이는 주로 리더 역할을 담당하는 감사인들에 의해 발생한다는 사실을 발견하였다.

• 대한토목학회논문집
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• 제13권2호
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• pp.141-149
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• 1993

수력에너지 생산량은 추계학적인 저수지 유입량에 지배되므로 전력량 판매 계약에는 이를 반영하여 합리성을 보장해야 할 필요가 있다. 본 연구에서는 유입량의 신뢰도별로 저수지조작(貯水池操作)을 수행하여 최적 신뢰도 및 이에 따른 최적 전력 판매계약량을 결정하는 방법을 제시하였다. 목적함수에는 전력생산량이 신뢰도를 벗어나는 위험에 대한 손실함수를 도입하고, 손실계수의 범위를 제시하였다. 여기서 손실은 계약량을 공급하지 못할 경우 지불해야 할 벌칙량을 의미하고 신뢰도는 저수지 유입량에 대한 초과 확률과 같고, 이 때 확률밀도함수는 대수정규분포를 5% 유의수준에서 채택하였다. 최적의 신뢰도를 결정하기 위하여 오목함수 범위에서 황금비 조사 기법을 썼으며, 신뢰도별 최대 수력 에너지를 얻기 위해 증분 동적계획 기법으로 저수지 조작을 수행하였다. 본 연구의 적용대상으로 대청 다목적댐 및 수력발전소를 택하여 손실계수, 최적 신뢰도 및 계약 발전량을 구하였다.