• Title, Summary, Keyword: risk assessment

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Development of Integrated Method and Tool for Railway Risk Assessment (철도 위험도 통합 평가 방법 및 도구 개발)

  • Han, Sang-Hoon;Ahn, Kwang-Il;Wang, Jong-Bae;Lee, Ho-Joong
    • Proceedings of the KSR Conference
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    • pp.1132-1139
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    • 2006
  • Railway risk is evaluated by a method of linking event trees and fault trees as the general PSA(Probabilistic Safety Assessment) model for the risk assessment of complex systems. Accident scenarios causing undesirable events are modeled by event trees comprised of several accident sequences. Each branch located in the accident progression of the event tree is modeled by an fault tree or can be represented by some value too simply. We usually evaluate the frequency of the whole sequence by adding them after calculating the frequency of each sequence at a time. However, since there are quite a number of event trees and fault trees in the railway risk assessment model, the number of sequence to evaluate increases and preparation for the risk assessment costs much time all the more. Also, it may induce errors when analysts perform the work of quantification. Therefore, the systematic maintenance and control of event trees and fault trees will be essential for the railway risk assessment. In this paper we introduce an integrated assessment method using one-top model and develop a risk assessment tool for the maintenance and control of the railway risk model.

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Development of the Risk Assessment Systems for Management of Sunken Ships (침몰선박의 관리를 위한 위해도 평가시스템 개발)

  • Choi, H.J.;Lew, J.M.;Kim, H.;Lee, S.H.;Kang, C.G.
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.8 no.4
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    • pp.193-202
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    • 2005
  • Marine risk assessment considers events such as collision/grounding, sinking/capsize, fire/explosion and flooding, developing relationships between their causes and effects. In addition, risk assessment of previously sunken ships are also necessary since they continuously have possibility for further oil spill or can cause other marine accidents. The objective of this paper is to develop the risk assessment systems for sunken ships to prevent oil spill and further marine causalities in order to preserve safe and clean oceans around Korea peninsula. The risk assessment systems for sunken ships comprise of database management sub-system for sunken ships, qualitative risk assessment sub-system, quantitative risk assessment sub-system, and cost-benefit analysis subsystem.

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Comprehensive Assessment on Risk Factors using Fuzzy Inference in Decommissioning Process (퍼지추론을 이용한 해체공정 중 리스크 요인의 통합 평가)

  • Lim, Hyeon Kyo;Kim, Hyunjung
    • Journal of the Korean Society of Safety
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    • v.29 no.4
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    • pp.184-190
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    • 2014
  • Decommissioning process of nuclear facilities consist of a sequence of problem solving activities, because there may exist not only working environments contaminated by radiological exposure but also industrial hazards such as fire, explosions, toxic materials, and electrical and physical hazards. Therefore, not a few countries in the world have been trying to develop appropriate counter techniques in order to guarantee safety and efficiency of the process. In spite of that, there still exists neither domestic nor international standard. Unfortunately, however, there are few workers who experienced decommissioning operations a lot in the past. As a solution, it is quite necessary to utilize experts' opinions for risk assessment in decommissioning process. As for an individual hazard factor, risk assessment techniques are getting known to industrial workers with advance of safety technology, but the way how to integrate those results is not yet. This paper aimed to find out an appropriate technique to integrate individual risk assessment results from the viewpoint of experts. Thus, on one hand the whole risk assessment activity for decommissioning operations was modeled as a sequence of individual risk assessment steps which can be classified into two activities, decontamination and dismantling, and on the other, a risk assessment structure was introduced. The whole model was inferred with Fuzzy theory and techniques, and a numerical example was appended for comprehension.

Risk of Material Misstatement in the Stage of Audit Planning: Empirical Evidence from Vietnamese Listed Enterprises

  • NGUYEN, Hoan;NGO, Thi Kieu Trang;LE, Thi Tam
    • The Journal of Asian Finance, Economics, and Business
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    • v.7 no.3
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    • pp.137-148
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    • 2020
  • The purpose of this study is to investigate factors influencing risk assessment of material misstatement in Vietnamese enterprises listed on stock market. Expert interview method was conducted to discover the scales for three variables including information system, trademark, and risk assessment of material misstatement. Survey method was used to examine the impacts of eight factors on risk assessment of material misstatement. Data is collected from 317 auditors who have excellent experience in auditing financial statements of companies listed on stock market. Then, data is processed by descriptive statistics, reliability analysis, factor extracted analysis, correlative regression analysis, and analysis variance of residual change. The research findings showed that business characteristic, stakeholder pressure, and economic environment have positive relationships with risk assessment of material misstatement. Three variables including operation control and monitor, control environment, and information system negatively affect to risk assessment. Specially, business characteristic and information system, which are elements in internal control, have strongest impact on risk assessment. One the other hand, assessment of internal control plays an important role not only in the audit plan stage but also throughout the stages of the audit implementation and ending. Therefore, appropriate solutions are proposed to carry out all audit stages.

An Objective Method of Risk Assessment Based on Stochastic Modelling (확률 기반의 위험등급평가 객관화 방안)

  • Shin, Sang-Sik;Lee, Kil-Soo;Cho, Heung-Gi
    • Journal of the Korean Society for Quality Management
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    • v.41 no.3
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    • pp.465-474
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    • 2013
  • Purpose: To provide a variety of stable military supplies, risk should be avoided or removed. This paper aims to provide an objective method of risk assesment for risk matrix to evaluate risk level. Methods: According to previous results of risk assesment through risk matrix, some parameters and probability density functions, which include characteristics of military supplies, are selected and Risk matrix is modelled based on that. Results: Results show that a proposed method can evaluate objectively risk level through the stochastic modelling and provide well-balanced risk assessments by categorizing into 3 levels such as high, middle and low level risk. Conclusion: A current risk assessment method includes substantial subjectivity of risk assessment and as a problem about military supplies comes up, we can not show any appropriate evidences for decision of risk assessment. We propose an objective scheme employing stochastic modelling with parameters and probability density functions.

A study on Risk Assessment Procedure for the Structural changes of Navigable Airspaces (공역의 구조적 변경에 따른 위험평가 절차 연구)

  • Kim, Do-Hyun;Kim, W.Y.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.20 no.1
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    • pp.13-18
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    • 2012
  • 'Navigable airspace' means an airspace at and above the minimum safe flight level, including airspace or flight procedures needed for safe takeoff and landing. Airspace may be established as needed and may be abolished, and in some cases may be limited to airspace management. These are absolutely based on risk assessment. Safety is the state in which the risk of harm to persons or of property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management. 'Risk' is the assessed potential for adverse consequences resulting from a hazard and 'Risk assessment' involves consideration of both the frequency and the severity of any adverse consequence. This paper proposed 'risk assessment procedure' for the structural changes of Navigable Airspaces through literature reviews relevant to manuals on airspace management and risk management.

Occupational Health Policies on Risk Assessment in Japan

  • Horie, Seichi
    • Safety and Health at Work
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    • v.1 no.1
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    • pp.19-28
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    • 2010
  • Industrial Safety and Health Law (ISH Law) of Japan requires abnormalities identified in evaluations of worker health and working environments are reported to occupational physicians, and employers are advised of measures to ensure appropriate accommodations in working environments and work procedures. Since the 1980s, notions of a risk assessment and occupational safety and health management system were expected to further prevent industrial accidents. In 2005, ISH Law stipulated workplace risk assessment using the wording "employers shall endeavor." Following the amendment, multiple documents and guidelines for risk assessment for different work procedures were developed. They require ISH Laws to be implemented fully and workplaces to plan and execute measures to reduce risks, ranking them from those addressing potential hazards to those requiring workers to wear protective articles. A governmental survey in 2005 found the performance of risk assessment was 20.4% and common reasons for not implementing risk assessments were lack of adequate personnel or knowledge. ISH Law specifies criminal penalties for both individuals and organizations. Moreover, under the Labor Contract Law promulgated in 2007, employers are obliged to make reasonable efforts to ensure employee health for foreseeable and avoidable risks. Therefore, enterprises neglecting even the non-binding provisions of guidelines are likely to suffer significant business impact if judged to be responsible for industrial accidents or occupational disease. To promote risk assessment, we must strengthen technical, financial, and physical support from public-service organizations, encourage the dissemination of good practices to reduce risks, and consider additional employer incentives, including relaxed mandatory regulations.

Comparative Study of Probabilistic Ecological Risk Assessment (PERA) used in Developed Countries and Proposed PERA approach for Korean Water Environment (확률생태위해성평가(PERA) 선진국 사례분석 및 국내수계에 적합한 PERA 기법 제안)

  • An, Youn-Joo;Nam, Sun-Hwa;Lee, Woo-Mi
    • Journal of Korean Society on Water Environment
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    • v.25 no.4
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    • pp.494-501
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    • 2009
  • Probabilistic Ecological risk assessment (PERA) is extensive approach to qualify and quantify risk on the multi species based on species sensitivity distribution (SSD). As a while, deterministic ecological risk assessment (DERA) considers the comparison of predicted no-effect concentration (PNEC) and predicted exposure concentration (PEC). DERA is used to determine if there is potential risk or no risk, and it doesn't consider the nature variability and the species sensitivity. But PERA can be more realistic and reasonable approach to estimate likelihood or risk. In this study, we compared PERA used in developed countries, and proposed PERA applicable for the Korean water environment. Taxonomic groups were classified as "class" level including Actinopterygill, Branchiopoda, Chlorophyceae, Maxillapoda, Insects, Bivalvia, Gastropoda, Secernentea, Polychaeta, Monocotyldoneae, and Chanophyceae in this study. Statistical extrapolation method (SEM), statistical extrapolation method $_{acutechronicratio}$ ($SEM_{ACR}$) and assessment factor method (AFM) were used to calculate the ecological protective concentration based on qualitative and quantitative levels of taxonomic toxicity data. This study would be useful to establish the PERA for the protection of aquatic ecosystem in Korea.