• Title/Summary/Keyword: Quantitative-Risk-Analysis

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Risk Analysis for Installation Types of Pressure Safety Valve used in the High-pressure Gas Facility (고압가스 사용시설 내 안전밸브 설치유형별 리스크 분석)

  • Kim, Myung-Chul;Woo, Jeong-Jae;Lee, Hyung-Sub;Baek, Jong-Bae
    • Journal of the Korean Society of Safety
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    • v.32 no.4
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    • pp.129-136
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    • 2017
  • This study investigated the probability of possible accident through qualitative and quantitative analysis of the pressure safety valve types installed in facilities using high pressure gas to compare the installation domestic and foreign pressure safety valve standards sought the safety characteristics and safety improvement direction accordingly. The three types are the case where the shut-off valve is not installed at the front of the PSV (Case A), If a shut-off valve is installed at the front of the PSV for inspection (Case B) and If a shut-off valve is installed in front of PSV (C.S.O), PSV is installed in parallel (Case C). Three types of cases were compared with FTA and HAZOP. The results of study of the possible accidents due to over-pressure safety valve installation type, used in a high-pressure gas facilities was shows in the following order Case B > Case A > Case C. The results of analysis through FTA was in order to protect the reservoir for the possible occurring of accident the safety valve installation is depend on its type. In the FTA analysis, defects in the device itself which attached to the storage tank as a substitute for analysis of the probability of operator mistakes was Case B with as high as $2.01{\times}10^{-6}$. Depending on the type of installation analysis of Case B in order to ensure safety is prohibited to install shut-off valve and believes that mandatory regulations are needed. Rationally installing of pressure safety valve in the high pressure using facilities will be expected to improve the industrial safety from severe accidents such as high-pressure gas fire explosion.

Study on the Selection and Application of a Spatial Analysis Model Appropriate for Selecting the Radon Priority Management Target Area (라돈 우선관리 대상 지역 선정에 적합한 공간분석모형의 선정 및 활용에 관한 연구)

  • Nam Goung, Sun Ju;Choi, Kil Yong;Hong, Hyung Jin;Yoon, Dan Ki;Kim, Yoon Shin;Park, Si Hyun;Kim, Yoon Kwan;Lee, Cheol Min
    • Journal of Environmental Health Sciences
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    • v.45 no.1
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    • pp.82-96
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    • 2019
  • Objective: The aims of this study were to provide the basic data for establishing a precautionary management policy and to develop a methodology for selecting a radon management priority target area suitable for the Korean domestic environment. Methods: A suitable mapping method for the domestic environment was derived by conducting a quantitative comparison of predicted values and measured values that were calculated through implementation of two models such as IDW and RBF methods. And a qualitative comparison including the clarity of information transmission of the written radon map was carried out. Results: The predicted and measured values were obtained through the implementation of the spatial analysis models. The IDW method showed the lowest in the calculated mean square error and had a higher correlation coefficient than the other methods. As results of comparing the uncertainty using the jackknife concept and the concept of error distance for comparison of the differences according to the model interpolation method, the sum of the error distances showed a modest increase compared with the RBF method. As a result of qualitatively comparing the information transfer clarity between the radon maps prepared with the predicted values through the model implementation, it was found that the maps plotted using the predicted values by the implementation of the IDW method had greater clarity in terms of highness and lowness of radon concentration per area compared with the maps plotted by other methods. Conclusions: The radon management priority area suggests selecting a metropolitan city including an area with a high radon concentration.

Clinical Implications of Focal Mineral Deposition in the Globus Pallidus on CT and Quantitative Susceptibility Mapping of MRI

  • Hyojin Kim;Jinhee Jang;Junghwa Kang;Seungun Jang;Yoonho Nam;Yangsean Choi;Na-young Shin;Kook-Jin Ahn;Bum-soo Kim
    • Korean Journal of Radiology
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    • v.23 no.7
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    • pp.742-751
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    • 2022
  • Objective: To assess focal mineral deposition in the globus pallidus (GP) by CT and quantitative susceptibility mapping (QSM) of MRI scans and evaluate its clinical significance, particularly cerebrovascular degeneration. Materials and Methods: This study included 105 patients (66.1 ± 13.7 years; 40 male and 65 female) who underwent both CT and MRI with available QSM data between January 2017 and December 2019. The presence of focal mineral deposition in the GP on QSM (GPQSM) and CT (GPCT) was assessed visually using a three-point scale. Cerebrovascular risk factors and small vessel disease (SVD) imaging markers were also assessed. The clinical and radiological findings were compared between the different grades of GPQSM and GPCT. The relationship between GP grades and cerebrovascular risk factors and SVD imaging markers was assessed using univariable and multivariable linear regression analyses. Results: GPCT and GPQSM were significantly associated (p < 0.001) but were not identical. Higher GPCT and GPQSM grades showed smaller gray matter (p = 0.030 and p = 0.025, respectively) and white matter (p = 0.013 and p = 0.019, respectively) volumes, as well as larger GP volumes (p < 0.001 for both). Among SVD markers, white matter hyperintensity was significantly associated with GPCT (p = 0.006) and brain atrophy was significantly associated with GPQSM (p = 0.032) in at univariable analysis. In multivariable analysis, the normalized volume of the GP was independently positively associated with GPCT (p < 0.001) and GPQSM (p = 0.002), while the normalized volume of the GM was independently negatively associated with GPCT (p = 0.040) and GPQSM (p = 0.035). Conclusion: Focal mineral deposition in the GP on CT and QSM might be a potential imaging marker of cerebral vascular degeneration. Both were associated with increased GP volume.

A Study of Proper Escape way interval by QRA on Single bored double track tunnel (정량적 위험도 분석을 이용한 복선철도터널에서의 적정 대피통로 간격 산정을 위한 연구)

  • Roh, Byoung-Kuk;Lee, Ho-Suk;Song, Myung-Kyu;Choo, Seok-Yeon
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.371-376
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    • 2007
  • This paper describes a study to determine proper escape way interval for the design phase of single bored double track tunnel. Among many methods which determine escape way interval, we choose a QRA(Quantitative Risk Analysis) method. But a different method must be chosen differ from other country because of special design situation of Korea. So, it is necessary to develop a method which considers a special design condition of Korea. Because fire accidents of railway tunnel are a rare event, simulated situation can be produced by CFD simulation and evacuation analysis simulation. However, it is generally difficult to estimate of fatalities from these methods, so a concept of FED is introduced to estimate of fatalities. Quantification process provides effective results for practical design stage and the result were employed in design.

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Extension of Rating Curve for High Water Level using Monte Carlo Simulation (MCS를 이용한 고수위 수위-유량관계곡선의 연장에 관한 연구)

  • Moon, Young-Il;Kim, Jong-Suk;Yoon, Sun-Kwon
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.683-686
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    • 2008
  • Flood damage has been increased due to the abnormal climate and extreme rainfall. So, quantitative and qualitative hydrologic data should be improved in oder to enhance accuracy of hydrologic forecast. However, research regarding hydrologic data have not been thorough enough. Therefore, in this study, monte carlo simulation was applied to rainfall runoff model to improve the reliability of runoff analysis and risk analysis. Rainfall-Stage-Discharge curve was developed as a consequence of MCS and it is possible to get correct rating curve for high water level.

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A Comparative Study on the Methods of Consequence Estimation in Fire and Explosion Hazards (화재 및 폭발재해의 강도 산정에 관한 비교 연구)

  • 김구회;백종배;고재욱
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.87-93
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    • 1993
  • Many methods to assess hazards caused by the risks increased with the growth of petrochemical industry. The manual of International Atomic Energy Agency which was much more applied to quantitative analysis of the real situation and the CPQRA is introduced to verify the theoretical background of this manual. Than other methods, as a result, we can see that this manual, which is simple to use and requires a little information, shows similar results to those of calculation by numerical formula. Also, the program code of this manual was materialized and if it is possible to obtain adequate parameters to our circumstance, the manual will be quite useful in early risk analysis.

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Feasibility Study of Fine Dust Removal Technology in Construction Site (건설현장 미세먼지 제거기술의 타당성 분석)

  • Kim, Kyoon-Tai
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.120-121
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    • 2019
  • The construction industry is known to be one of the representative industries that generate fine dust. Therefore, reducing the amount of fine dust generated in construction sites is very important for the overall fine dust management. Based on this, this study proposed the concept of fine dust measurement and removal technology combined with advanced technologies such as drones and IoT. The qualitative, quantitative and risk elimination effects that can be expected when applying the proposed technique are analyzed. We will verify the effectiveness of the proposed concept through system development and field application, and evaluate specific economic feasibility through cost analysis. The proposed concept will be validated through system development and field application and evaluated specific economics through cost analysis.

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Knowledge and Beliefs of Malaysian Adolescents Regarding Cancer

  • Al-Naggar, Redhwan Ahmed;Jillson, Irene Anne;Abu-Hamad, Samir;Mumford, William;Bobryshev, Yuri V.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1097-1103
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    • 2015
  • Background: Few studies have explored the knowledge and attitudes of adolescents toward cancer prevention and treatment. This lack of research and its potential utility in the development of new educational initiatives and screening methods, or the reconstruction of existing ones, provided the impetus for this study. The primary research aim was to assess secondary school student knowledge of cancer and determine whether or not they possessed basic knowledge of cancer symptoms, risk factors, and treatments and to determine the relationship between cancer knowledge and key demographic factors. Materials and Methods: The Management and Science University conducted a cross-sectional study analyzing responses through cross-tabulation with the socio-demographic data collected. Results: The findings of our quantitative analysis suggest that Malaysian youth generally possess a moderate knowledge about cancer. Quantitative analyses found that socioeconomic inequalities and bias in education present as important factors contributing to cancer awareness, prevention, and treatment among Malaysian adolescents. Conclusions: The findings indicate that Malaysian youth generally possess a moderate knowledge about cancer but the current deficiencies in initiatives directed to cancer awareness continue to hinder the improvement in prevention of cancer among Malaysian adolescents.

The Effect Analysis of COVID-19 vaccination on social distancing (코로나19 백신접종이 사회적 거리두기 효과에 미치는 영향분석)

  • Moon, Su Chan
    • Journal of the Korea Convergence Society
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    • v.13 no.2
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    • pp.67-75
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    • 2022
  • The purpose of this study is to present an appropriate management plan as a supplement to the scientific evidence of the currently operated distancing system for preventing COVID-19. The currently being used mathematical models are expressed as simultaneous ordinary differential equations, there is a problem in that it is difficult to use them for the management of entry and exit of small business owners. In order to supplement this point, in this paper, a method for quantitatively expressing the risk of infection by people who gather is presented in consideration of the allowable risk given to the gathering space, the basic infection reproduction index, and the risk reduction rate due to vaccination. A simple quantitative model was developed that manages the probability of infection in a probabilistic level according to a set of visitors by considering both the degree of infection risk according to the vaccination status (non-vaccinated, primary inoculation, and complete vaccination) and the epidemic status of the virus. In a given example using the model, the risk was reduced to 55% when 20% of non-vaccinated people were converted to full vaccination. It was suggested that management in terms of quarantine can obtain a greater effect than medical treatment. Based on this, a generalized model that can be applied to various situations in consideration of the type of vaccination and the degree of occurrence of confirmed cases was also presented. This model can be used to manage the total risk of people gathered at a certain space in a real time, by calculating individual risk according to the type of vaccine, the degree of inoculation, and the lapse of time after inoculation.

Association between diets and mild cognitive impairment in adults aged 50 years or older

  • Kim, Kyoung Yun;Yun, Jung-Mi
    • Nutrition Research and Practice
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    • v.12 no.5
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    • pp.415-425
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    • 2018
  • BACKGROUND/OBJECTIVE: As aging progresses, the number of patients with cognitive impairment also increases. Cognitive function is not generally correlated with diet, and there is debate over that association. Thus, the present study aimed to investigate the association between dietary intake and cognitive function among adults aged 50 years or older. SUBJECTS/METHODS: Between July 2017 and March 2018, 324 adults aged over 50 years from Gwangju Sun-Han hospital participated in a dietary survey. The frequency of food intake and related information were collected using a semi-quantitative food frequency questionnaire (SQ-FFQ) and determining the mini-mental state examination (MMSE) level for 276 participants. The association between dietary intake and cognitive function was assessed by performing logistic regression analysis. RESULTS: Depending on the MMSE score, the participants' age, education level, inhabitation status, medications, alcohol consumption, sleep duration, physical activity, and short geriatric depression scale score were significantly different (P < 0.05). Moreover, those participant characteristics were associated with either decreased or increased odds ratios (OR) for the risk of mild cognitive impairment (MCI). Based on analysis of the participants' intake of 112 detailed food items, which were categorized into 20 food types, intakes of cooked white rice (< 2 times/day compared with ${\geq}3$ times/day) (P < 0.05), properly cooked rice with other grains and legumes (P < 0.001), fruits (P < 0.05), milk (low fat and normal) (P = 0.044), liquid-type yogurt (P = 0.019), and curd-type yogurt (P = 0.015) were found to significantly decrease the OR for the risk of MCI. CONCLUSIONS: Associations were significant between the risk of MCI and the intake of certain food types. Specifically, a moderate intake of cooked white rice and an adequate intake of whole grains, fruits, milk, and dairy products were associated with reduced risks of MCI among adults aged over 50 years.