• Title/Summary/Keyword: risk frequency

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A Study on Safety Improvement for Packaged Hydrogen Refueling Station by Risk Assessment (위험성 평가를 통한 패키지형 수소충전소 안전성 향상에 관한 연구)

  • KANG, SEUNGKYU;HUH, YUNSIL;MOON, JONGSAM
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.6
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    • pp.635-641
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    • 2017
  • In this study, the components of packaged hydrogen filling station were analyzed and risk factors were examined. Risk scenarios were constructed and quantitative risk assessments were conducted through a general risk assessment program (phast/safeti 7.2). Through the risk assessment, the range of damage according to accident scenarios and the ranking that affects the damage according to the risk factors are listed, and scope of damage and countermeasures for risk reduction are provided. The quantitative risk assessment result of the packaged hydrogen filling station through this task will be used as the basic data for improving the safety of the packaged filling system and preparing safety standards.

Development of Fuzzy Model for Analyzing Construction Risk Factors (건설공사의 리스크분석을 위한 퍼지평가모형 개발)

  • Park Seo-Young;Kang Leen-Seok;Kim Chang-Hak;Son Chang-Bak
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.519-524
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    • 2001
  • Recently, our construction market recognizes the necessity of risk management, however the application of practical system is still limited on the construction site because the methodology for analyzing and quantifying construction risk and for building actual risk factors is not easy. This study suggests a risk management method by fuzzy theory, which is using subjective knowledge of an expert and linguistic value, to analyze and Quantify risk. The result of study is expected to improve the accuracy of risk analysis because three factors, such as probability, impact and frequency, for estimating membership function are introduced to quantify each risk factor.

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The Influence of Customer's Perceived Risk on Perception of Value (Focused on Family Restaurants in Seoul) (외식 고객의 지각된 위험이 가치인지에 미치는 영향 (서울 지역의 패밀리레스토랑을 대상으로))

  • Yoon, Tae-Hwan;Kim, Young-Jin;Choi, Sung-Man
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.6
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    • pp.919-925
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    • 2007
  • The purpose of this study was to investigate the influence of customers' perceived risks on their perception of value at family restaurants in Seoul. Frequency analysis, reliability analysis, factor analysis, multiple-regression analysis were employed to analyze the data. The customers' perceived risk were divided into 6 factors. Three of the perceived risk factors(financial, time, performance risk) negatively(-) influenced the perception of value. In particular, 'financial risk' was the most negative. However, 3 factors(physical risk, psychological risk, social risk) didn't have significant influence on perceived risk. As a result, customers of family restaurants appear to perceive various risks, and these risks have significant impacts on their perception of value. Therefore, food-service corporations need to reduce customers' perceived risks, possibly by various and efficient pricing-policies, discount, price-bundling, using coupon, effective physical evidence and offering unique compensation.

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A Study on Risk Assessment and Risk Mitigation Measures of Liquefied Chlorine Leak (액화염소 누출의 위험도 분석 및 위험경감조치에 대한 연구)

  • Lee, Ju-Youn;Chon, Young-Woo;Hwang, Yong-Woo;Lee, Ik-Mo
    • Journal of the Korea Safety Management & Science
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    • v.20 no.1
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    • pp.1-9
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    • 2018
  • As the chemical industry becomes more advanced, the awareness of chemical accidents is rising, and legal systems for chemical safety management are strengthened. In this study, quantitative risk assessment of liquid chlorine leak was conducted. Risk assessment was performed in the order of frequency analysis, consequence analysis, and risk calculation. The individual risk was presented in the form of contour lines. The social risk was expressed by the FN curve. The risk of day and night was in an unacceptable area, so it was required to mitigate risk. Therefore in-building, which could trap the pool, was selected as a risk mitigation measure. As a result of the cost benefit analysis, it was concluded that this measure should be reasonably implemented.

A Study on the Risk Analysis of Construction Method (건축공법 내부 리스크 분석에 관한 연구)

  • Yoon, Yer-Wan;Yang, Keek-Young
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.4
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    • pp.131-135
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    • 2002
  • The purpose of this study was to Identification the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of Construction field. So we rearrange the individual item of inspection list to match the Risk factor. This inspection list usually has the difference of importance because this list is not made by Method which is not focused on Method. Therefore, To find the difference of these importance, We surveyed this matter by doing interview of specialist group. To find the application of field and the possibility of measurement of Risk status, We tested Risk occurring frequency and it's strength by checking the level of Risk. The results of this study were as follows; Each Method Check List made out through the rearrangement of Construction Inspection list which used in construction company. To solve and compensate the matter which happened by changing the each Method Check List to each General Inspection List, we added the each Method Check List by checking the importance of check list of each process. By doing this, The Check List for finding Risk level of Method was created by using the check list of each Method.

Seasonal Variation of Acute Stroke;Hospital Based Study

  • Yun, Sang-Pil;Jung, Woo-Sang;Moon, Sang-Kwan;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup
    • The Journal of Korean Medicine
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    • v.29 no.2
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    • pp.1-6
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    • 2008
  • Objectives: This study aimed to investigate the seasonal variation in stroke types, ischemic stroke subtypes, stroke risk factors and Sasang constitutions. Methods: 226 patients with acute stroke within 14 days onset were included, who were admitted to Kyunghee Oriental Medical Center from November 2005 to October 2006. The year was subdivided into four parts: spring (March-May); summer (June-August); fall (September-November); and winter (December-February). Stroke types, ischemic stroke subtypes, stroke risk factors and Sasang constitutions in the four groups were examined. Results: Ischemic stroke was most frequent in summer, whereas hemorrhagic stroke was most frequent in winter. There was no significant difference in seasonal variation of stroke. The frequency of ischemic heart disease among stroke risk factors was significantly high in spring (p=0.031). The frequency of hypertension, diabetes mellitus, atrial fibrillation, and hyperlipidemia did not differ among seasons. There was no significant difference in Sasang constitution among seasons. Frequency of small vessel occlusion was highest in summer. Large artery atherosclerosis was frequent in spring and summer,but seasonal variation of ischemic stroke subtypes did not show statistical difference. Conclusion: Acute stroke demonstrates seasonal characteristics according to stroke types, ischemic stroke subtypes, risk factors for stroke, and Sasang constitutions. These results have important clinical implications in stroke prevention.

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The Risk Analysis and Stability Estimation of Ship Collision Protection of Myodo-Gangyang Suspension Bridge (묘도-광양간 현수교의 선박충돌 방지공의 위험도 분석 및 안정성 평가)

  • Chang, Yong-Chai;Park, Ki-Chul;Kim, Kyung-Taek
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.2
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    • pp.127-133
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    • 2009
  • The suspension bridge between Myodo and Gwangyang is located in the main navigation channel to Gwangyang Harbor. So, there is need for the collision protection against large vessels. In this paper, the method of risk analysis and non-linear numerical analysis are conducted to consider the ship collision effects. The results of risk analysis, the annual frequency of collapse is more than the acceptable frequency 0.0001. Therefore, as a ship collision protection, island protection with concrete block quay wall is planned. The ship collision force on the pylon is less than the lateral capacity of pylon from the nonlinear numerical analysis.

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The MMP-2 -735 C Allele is a Risk Factor for Susceptibility to Breast Cancer

  • Yari, Kheirollah;Rahimi, Ziba;Moradi, Mohamad Taher;Rahimi, Zohreh
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6199-6203
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    • 2014
  • Background: The expression of MMP genes has been demonstrated to be associated with tumor invasion, metastasis and survival rate for a variety of cancers. The functional promoter polymorphism MMP-2 C-735T is associated with decreased expression of the MMP-2 gene. The aim of present study was to detect any association between MMP-2 C-735T and susceptibility to breast cancer. Materials and Methods: The MMP-2 C-735T polymorphism was studied in 233 women (98 with breast cancer and 135 healthy controls). All studied women were from Kermanshah and Ilam provinces of Western Iran. The MMP-2 C-735T polymorphism was detected using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The frequencies of MMP-2 CC, CT and TT genotypes in healthy individuals were 59.3, 38.5 and 2.2%, respectively. However, in breast cancer patients, only CC (71.4%) and CT (28.6%) genotypes were observed (p=0.077). In patients the frequency of the MMP-2 C allele was significantly higher (85.7%) compared to that in controls (78.5 %, p=0.048). The presence of C allele of MMP-2 increased the risk of breast cancer by 1.64-fold [OR=1.64 (95%CI 1.01-2.7, p=0.049)]. The frequency of MMP-2 C allele was also higher in patients ${\leq}40$ years (88.9%) than those aged ${\geq}41$ years (67.5%, p=0.07). In addition, the frequency of MMP-2 C allele tended to be higher in patients with a family history of cancer in first-degree relatives (76.6%) compared to that without a family history of cancer (67.3%, p=0.31). Conclusions: Our findings indicate that the C allele of MMP-2 C-735T polymorphism is associated with increased risk of breast cancer. Also, the MMP-2 C allele might increase the risk of young onset breast cancer in our population.

Risk Model Development for PWR During Shutdown (원자로 정지 동안의 위해도 모델 개발)

  • Yoon, Won-Hyo;Chang, Soon-Heung
    • Nuclear Engineering and Technology
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    • v.21 no.1
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    • pp.1-11
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    • 1989
  • Numerous losses of decay heat removal capability have occurred at U during stutodwn while its significance to safety is needless to say. A study is carried out as an attempt to assess what could be done to lower the frequency of these events and to mitigate their consequences in the unlikely event that one occurs. The shutdown risk model is developed and analyzed using Event/Fault Tree for the typical pressurized water reactor. The human cognitive reliability (HCR) model, two-stage bayesian approach and staircase function model are used to estimate human reliability, initiating event frequency and offsite power non-recovery probability given loss of offsite power, respectively. The results of this study indicate that the risk of a Pm at shutdown is not much lower than the risk when the plant is operating. By examining the dominant accident sequences obtained, several design deficiencies are identified and it is found that some proposed changes lead to significant reduction in core damage frequency due to loss of cooling events.

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Performance Evaluation of Deep Neural Network (DNN) Based on HRV Parameters for Judgment of Risk Factors for Coronary Artery Disease (관상동맥질환 위험인자 유무 판단을 위한 심박변이도 매개변수 기반 심층 신경망의 성능 평가)

  • Park, Sung Jun;Choi, Seung Yeon;Kim, Young Mo
    • Journal of Biomedical Engineering Research
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    • v.40 no.2
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    • pp.62-67
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    • 2019
  • The purpose of this study was to evaluate the performance of deep neural network model in order to determine whether there is a risk factor for coronary artery disease based on the cardiac variation parameter. The study used unidentifiable 297 data to evaluate the performance of the model. Input data consists of heart rate parameters, which are SDNN (standard deviation of the N-N intervals), PSI (physical stress index), TP (total power), VLF (very low frequency), LF (low frequency), HF (high frequency), RMSSD (root mean square of successive difference) APEN (approximate entropy) and SRD (successive R-R interval difference), the age group and sex. Output data are divided into normal and patient groups, and the patient group consists of those diagnosed with diabetes, high blood pressure, and hyperlipidemia among the various risk factors that can cause coronary artery disease. Based on this, a binary classification model was applied using Deep Neural Network of deep learning techniques to classify normal and patient groups efficiently. To evaluate the effectiveness of the model used in this study, Kernel SVM (support vector machine), one of the classification models in machine learning, was compared and evaluated using same data. The results showed that the accuracy of the proposed deep neural network was train set 91.79% and test set 85.56% and the specificity was 87.04% and the sensitivity was 83.33% from the point of diagnosis. These results suggest that deep learning is more efficient when classifying these medical data because the train set accuracy in the deep neural network was 7.73% higher than the comparative model Kernel SVM.