• 한국대기환경학회지
• /
• 제29권1호
• /
• pp.1-9
• /
• 2013

Hazardous Air Pollutants (HAPs) are difficult to measure, analyze and assess for risk because of low ambient concentrations and varieties. Types of HAPs are Volatile organic compounds (VOCs), Polycyclic aromatic hydrocarbon (PAHs) and Aldehydes. HAP emissions from vehicles are a contributor to serious adverse health effects in urban areas. In this study, hazardous air pollutant emissions from road transport vehicles by Non-methane volatile organic compounds (NMVOC) weight fraction and PAHs emission factors are estimated in 2008. The top-five-most hazardous air pollutant emissions were estimated to toluene 864.3 ton/yr, acrolein 690.6 ton/yr, acetaldehyde 554.5 ton/yr, formaldehyde 498.7 ton/yr, propionaldehyde 421.6 ton/yr in 2008. The results for a cancer and non-cancer risk assessment of HAPs emissions show that the major cancer driver is formaldehyde and the non-cancer driver is acrolein.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권5호
• /
• pp.3169-3173
• /
• 2013

Background: Findings from previous published studies regarding the association of the XRCC3 Thr241Met polymorphism with glioma susceptibility have often been conflicting. Therefore, a meta-analysis including all available publications was carried out to make a more precise estimation of the potential relationship. Methods: By searching the electronic databases of Pubmed and Embase (up to April 1st, 2013), a total of nine case-control studies with 3,752 cases and 4,849 controls could be identified for inclusion in the current meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association. Results: This meta-analysis showed the XRCC3 Thr241Met polymorphism to be significantly associated with decreased glioma risk in the allelic model (Met allele vs. Thr allele: OR= 0.708, 95%CI= 0.631-0.795). Moreover, we also observed a statistically significant association between the XRCC3 Thr241Met polymorphism and reduced glioma risk in analyses stratified by ethnicity (Asian) and source of controls (hospital based) in the allelic model. Conclusions: Current evidence suggests that the XRCC3 Thr241Met polymorphism may be a risk factor for glioma development, especially in Asians.

• 대한안전경영과학회지
• /
• 제7권3호
• /
• pp.1-15
• /
• 2005

Recently in Korean Society, risk and safety has become a central discourse in not only the social and natural science but also political decision making. The efficient organizational management contributes to controlling the risk factors in the workplace. For the management is influenced and improved by the organizational culture, the alternatives more than simply improving the work environment or enforcing the education of safety on each workers are required. This study was the status of safety culture in organizational members(managers and workers, and specialist) including the attitude on the safety atmosphere and risk perception, and experiences, knowledges, motivation etc. For this part, the method of questionnaire and statistical analysis are mobilized. The degree of safety commitment of organization members appears relatively high (3.97 in five scale estimation), but there are variations in this results according to socio-demographic characteristics. At the same time, managers and professionals actively participation in the program related to safety than workers in production/sales. The higher income level and career is the more attention to the safety is. Based on this survey, we make an rough suggestion of several tasks to the policy -makers: improvement of communication on the risk and safety is required and in particular, the workers in the relatively low level in production/sales. The education system about safety which is, with one-side, provided by government or managers turns out to be inefficient. Rather, small group performance of the organizational members which they participate in the communication with interaction in the various discourse are able to provoke the safety mood in workplace.

• 응용통계연구
• /
• 제29권4호
• /
• pp.753-771
• /
• 2016

금융기관의 위험관리를 위한 중요한 도구로서 현재 VaR가 널리 사용되고 있다. 본 논문에서는 코퓰러 함수들을 이용하여 극단치이론과 GARCH 모형을 결합한 일변량분포로부터 구축한 다변량분포들을 바탕으로 코스피, 다우존스, 상하이 그리고 니케이 지수들로 구성된 포트폴리오의 VaR 추정과 그 성과에 관해 논의하였다. 사후검증 결과 전체적으로 볼 때 가우시안, t, 클레이톤, 프랭크 코퓰러를 사용한 t-분포의 오차항을 가진 변동성 모형들이 포트폴리오 VaR의 측정에 적합한 모형들로 나타났으며, 특히 프랭크 코퓰러의 경우에 가장 우수한 성과를 나타내었다.

• 응용통계연구
• /
• 제34권6호
• /
• pp.875-887
• /
• 2021

최대예상손실액(VaR)은 위험관리수단으로 금융에서 시장위험을 측정하는 대표적인 값이다. 본 논문에서는 다양한 자산으로 이루어진 고차원 금융자료에서 자산들 간의 의존성 구조를 잘 설명할 수 있는 성근 바인 코풀라를 이용한 VaR 추정에 대해서 논의한다. 성근 바인 코풀라는 정규 바인 코풀라 모형에 벌점화를 적용한 방법으로 추정하는 모수의 개수를 벌점화를 통해 축소하는 방법이다. 모의 실험 결과 성근 바인 코풀라를 이용한 VaR 추정이 더 작은 표본 외 예측오차를 줌을 살펴볼수 있었다. 또한 최근 5년간의 코스피 60개 종목을 바탕으로 실시한 실증 자료 분석에서도 성근 바인 코풀라 모형이 더 좋은 예측 성능을 보임을 확인할 수 있었다.

• Safety and Health at Work
• /
• 제12권2호
• /
• pp.174-183
• /
• 2021

Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.

• 한국환경보건학회지
• /
• 제49권1호
• /
• pp.1-10
• /
• 2023

Low-dose radiation exposure has received considerable attention because it reflects the general public's type and level of exposure. Still, controversy remains due to the relatively unclear results and uncertainty in risk estimation compared to high-dose radiation. However, recent epidemiological studies report direct evidence of health effects for various types of low-dose radiation exposure. In particular, international nuclear workers' studies, CT exposure studies, and children's cancer studies on natural radiation showed significantly increased cancer risk among the study populations despite their low-dose radiation exposure. These studies showed similar results even when the cumulative radiation dose was limited to an exposure group of less than 100 mGy, demonstrating that the observed excess risk was not affected by high exposure. A linear dose-response relationship between radiation exposure and cancer incidence has been observed, even at the low-dose interval. These recent epidemiological studies include relatively large populations, and findings are broadly consistent with previous studies on Japanese atomic bomb survivors. However, the health effects of low-dose radiation are assumed to be small compared to the risks that may arise from other lifestyle factors; therefore, the benefits of radiation use should be considered at the individual level through a balanced interpretation. Further low-dose radiation studies are essential to accurately determining the benefits and risks of radiation.

• 한국산업융합학회 논문집
• /
• 제26권2_2호
• /
• pp.315-325
• /
• 2023

Recently, various dynamic risk analysis methods have been suggested for estimating the risk index by predicting the possibility of accidents and damage. It is necessary to maintain and support the safety system for responding to accidents by continuously updating the probability of accidents and the results of accidents, which are quantitative standards of ship risk. In this study, when a LNG leakage that may occur in the LN G Fuel Gas Supply System (FGSS) room during LN G bunkering operation, a reliability physical model was prepared by the change in monitoring data as physical parameters to estimate the accident probability. The scenario in which LNG leakage occur were configured with FT (Fault Tree), and the coefficient of the covariate model and Weibull distribution was estimated based on the monitoring data. The possibility of an LNG leakage, which is the top event of FT, was confirmed by changes in time and monitoring data. A method for estimating the LNG leakage based on the reliability physical analysis is proposed, which supports fast decision-making by identifying the potential LNG leakage at the accident.

• 대한기계학회논문집B
• /
• 제38권12호
• /
• pp.971-974
• /
• 2014

심실보조장치는 심장질환자에게 심장이식까지의 가교로서 사용된다. 공압식 박동형 심실보조장치를 체내에 이식했을 때, 심실보조장치를 통과하는 혈류가 느려질 경우 혈전이 발생할 수 있기 때문에 박출량을 측정하는 것이 중요하다. 심실보조장치의 박출량을 측정하기 위해 각종 센서를 함께 이식할 경우, 감염의 위험성이 커지기 때문에 본 연구에서는 체외에서 측정할 수 있는 공압관 내 압력을 통해 심실보조장치의 상태를 추정하고자 한다. 체외실험을 통해 공압식 박동형 심실보조장치의 공압관 내 차동압력과 심실보조장치 박출량의 상관관계를 계산하였다. Pearson correlation coefficient r=0.623 으로 두 값의 상관관계가 높으며, 박출량 추정값과 측정값에서 오차가 있었지만 공기 분자의 이동에 따른 식을 개발하여 박출량 추정의 정확성을 높일 수 있을 것으로 보인다.

• 한국지능시스템학회논문지
• /
• 제26권6호
• /
• pp.452-457
• /
• 2016

본 논문은 택시 탑승 불안감을 감소시키고 승객의 만족도를 증가시키기 위하여 비콘 단말기를 사용한 택시안심이용시스템을 제안하였다. 먼저 택시 내부에 간편하게 장착 할 수 있는 USB형태의 저전력 비콘 단말기를 설계하였으며, 비콘 신호세기를 이용한 거리 및 위치 추정 방법을 제안하였다. 비콘 신호를 기반으로 동작하는 승객 및 운전자의 모바일 어플리케이션을 개발하였으며, 택시 승객의 상황 인식, 위치 측위, 위험 관리 및 알림 등을 수행하는 중앙관제실의 서버용 운영프로그램도 개발하였다. 또한 택시 승객의 상하차 및 거리 인식을 통하여 사고 위험 관리 방법도 제안하였다. 본 연구에서 제안한 방법들은 실제 실험을 통해 적용 가능성과 유용성을 검증하였다.