• Title/Summary/Keyword: risk analysis and evaluation

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Risk Assessment for Performance Evaluation System of Hydrogen Refueling Station (수소충전소 성능평가 장비 안전성 평가 연구)

  • KANG, SEUNGKYU;LEE, DONGHOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.3
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    • pp.232-239
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    • 2022
  • This study performed qualitative and quantitative risk assessment of equipment for evaluating the protocol of hydrogen refueling stations and suggested measures to improve safety. Hazard and operability study was performed for qualitative risk assessment, and Hy-KoRAM was used for quantitative risk assessment. Through a qualitative risk assessment, additional ventilation devices were installed, simultaneous venting of the storage container was prohibited, and the number of repeated refilling of the evaluation equipment was identified to manage the number of fillings of the container. Through quantitative risk assessment, the area around the device was set as a restricted area when evaluating the station, and measures were suggested to reduce the frequency of accidents.

A Study of the Risk Analysis Technique Optimization in the Pre-Project Evaluation Phase of the Development Projects (개발사업 사전평가단계에 적용하는 위험분석기법 최적화 연구)

  • Kim, Han;Kim, Seon-Gyoo
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.517-520
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    • 2008
  • The city refreshing development projects in the domestic recently have been performed under leading of public institution laying stress on new city and existing urban district. These development projects are still staying in safety control level despite risk factor management at preliminary estimation stage has been more important factor to success and add value creation. Understanding inaccurately about various risk analysis techniques that can analyze risk factors and the insufficient application of step that can analysis technique s could make projects more difficult. Therefore, this research suggests the more effective methods for risk analysis that can control the risks in the pre-project evaluation stage.

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Credit Risk Evaluations of Online Retail Enterprises Using Support Vector Machines Ensemble: An Empirical Study from China

  • LI, Xin;XIA, Han
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.8
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    • pp.89-97
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    • 2022
  • The e-commerce market faces significant credit risks due to the complexity of the industry and information asymmetries. Therefore, credit risk has started to stymie the growth of e-commerce. However, there is no reliable system for evaluating the creditworthiness of e-commerce companies. Therefore, this paper constructs a credit risk evaluation index system that comprehensively considers the online and offline behavior of online retail enterprises, including 15 indicators that reflect online credit risk and 15 indicators that reflect offline credit risk. This paper establishes an integration method based on a fuzzy integral support vector machine, which takes the factor analysis results of the credit risk evaluation index system of online retail enterprises as the input and the credit risk evaluation results of online retail enterprises as the output. The classification results of each sub-classifier and the importance of each sub-classifier decision to the final decision have been taken into account in this method. Select the sample data of 1500 online retail loan customers from a bank to test the model. The empirical results demonstrate that the proposed method outperforms a single SVM and traditional SVMs aggregation technique via majority voting in terms of classification accuracy, which provides a basis for banks to establish a reliable evaluation system.

Risk Analysis System in Fuzzy Set Theory (퍼지 집합론을 이용한 위험분석 시스템)

  • 홍상우
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.13 no.21
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    • pp.29-41
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    • 1990
  • An assessment of risk in industrial and urban environments is essential in the prevention of accident and in the analysis of situations which are hazardous to public health and safety. The risk imposed by a particular hazard increases with the likelihood of occurence of the event, the exposure and the possible consequence of that event. In a traditional approach, the calculation of a quantitative value of risk is usually based on an assignment of numerical values of each of the risk factors. Then the product of the values of likelihood, exposure and consequences called risk score is derived. However vagueness and imprecision in mathematical quantification of risk are equated with fuzziness rather than randomness. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the area of systems safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique based on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.

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Development of Risk-Appearance Frequency Evaluation Model for Railway Level-Crossing Accidents (철도건널목 사고 위험도-발생빈도 평가모델 개발)

  • Kim, Min-Su;Wang, Jong-Bae;Park, Chan-Woo;Choi, Don-Bum
    • Journal of the Korean Society of Safety
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    • v.24 no.3
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    • pp.96-101
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    • 2009
  • In this study, a risk-appearance frequency evaluation model for railway level-crossing accidents is developed with the frequency estimation based on the accident history. It follows the worldwide common safety management approach and reflects the operation conditions and accident properties of the domestic railway system. The risk appearance frequency evaluation process contains a development of accident scenarios by defining the system configurations and functions, and a frequency estimation of hazardous events based on the accident history. The developed model is verified with the accident history during 5 years('03-'07) for 3 hazardous events: 'Being trapped in level crossing(Hl)', 'Crossing during warning signal(H2)' and 'Breaking through/detouring the barrier(H3)'. This risk appearance frequency evaluation model will be combined with a consequence evaluation model so as to offer full risk assessment for the railway accident. The accident risk assessment will contribute to improving the safety management of the railway system.

Developing an Evaluation Tool of RFID-based Traceability Systems

  • Kim, Jin-Baek
    • The Journal of Fisheries Business Administration
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    • v.39 no.3
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    • pp.1-23
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    • 2008
  • Recently, traceability systems are introduced as a new food safety information system. To trace food products efficiently, they must have an automatic identification capability at the individual product level. This capability can be gained through RFID technology. But there is not yet any performance evaluation tool on RFID-based traceability systems (RFID-TS). This study developed an evaluation tool of RFID-TS. To develop the tool, this study considered the objective and the components of RFID-TS as their performance constructs. According to Churchill's paradigm, the tool was established through two stages. The final evaluation tool consisted of four constructs (risk, operational benefits, IS (information system), and network) and nine sub-constructs. Among the four constructs, risk and IS were found as the most important performance constructs through regression analysis. Among the nine sub-constructs, service (which belonged to the IS construct) and economic risk (which belonged to the risk construct) were found as the most important performance sub-constructs.

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Comparison of Relative Risk before and after SEMI S2-93A Implementation: Using a Semiconductor Plant in a Taiwan's Science Park as an Example

  • Tien, Shiaw-Wen;Chung, Yi-Chan;Tsai, Chihj-Hung;Hwang, Guo-Ji
    • International Journal of Quality Innovation
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    • v.6 no.1
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    • pp.58-73
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    • 2005
  • The objective of this study is to evaluate the equipment risk before and after SEMI S2-93A implementation, thus providing a guideline for safety improvement. Semiconductor Plant A located in Taiwan's Hsinchu Science Based Industrial Park with 147 manufacturing machines was used for risk assessment. This study was carried out in three steps. First, a preliminary hazard analysis was conducted. A detailed process safety evaluation was conducted (Hazard and Operability Study, HAZOP); and finally, the equipment risk comparison before and after Semiconductor Equipment Manufacturing Instruction (SEMI S2-93A) implementation. The preliminary hazard analysis results showed high risk in 21.77% of the manufacturing machines under risk assessment at Plant A. The largest percentage existed in the Diffusion Department. The machine types specified by the hazardous work site review and inspection according to Article 26 of Labor Inspection Regulation (the machines that use such chemicals as, $SiH_4$, HF, HCL, etc. and that are determined to be highly hazardous through preliminary hazard analysis) were added to the detailed process analysis and evaluation. In the third part of this evaluation, the machines at Plant A used for detailed process safety assessment were divided into two groups based on the manufacturing data before and after 1993. The severity, possibility, and actual accident analysis before and after SEMI S2-93A implementation were compared. The Semiconductor Equipment Manufacturing Instruction (SEMI S2-93A) implementation can reduce the severity and possibility of hazard occurrence.

ISO14971:2019 Detailed Analysis and Periodic Safety Update Report Establishment Method for the Single Use Medical Device - Focusing on Medical Device Regulation 2017/745 requirements (일회용 의료기기에 적용을 위한 ISO 14971:2019 분석과 Periodic Safety Update Report 작성 방법 - Medical Device Regulation 2017/745 요구사항 중심으로)

  • Sang Min, Park;Gyu Ha, Ryu
    • Journal of Biomedical Engineering Research
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    • v.44 no.1
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    • pp.1-10
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    • 2023
  • With the announcement of MEDICAL DEVICE REGULATION 2017/745 (MDR) on April 5 2017, medical device manufacturers shall apply ISO 14971:2019 (3rd) revised in December 2019. However, there is not much related information and guidance available to medical device manufacturers, especially single use medical device. Risk management process basically follow 5 steps which are Risk Analysis, Risk Evaluation, Risk Control, Evaluation of overall residual risk and post-production activities. The purpose of this study is to provide a guidance of from risk analysis with Failure Mode and Effects Analysis (FMEA) table to overall residual risk evaluation for the single use medical device and to reflect it in a Periodic Safety Update Reports (PSUR) to satisfy with MDR requirements with single use medical device which are widely used and manufactured FDA class 2 or CE class IIb as examples. For this study, single use medical device manufacturer can adopt ISO 14971:2019 in accordance with MDR requirements and it can be extended to the PSUR. But there are still limitations to adopt to the all-single use medical device especially high class, private device and implantable device. So, Competent Authority (CA) shall publish more guidance for the single use medical device.

THREE-STAGED RISK EVALUATION MODEL FOR BIDDING ON INTERNATIONAL CONSTRUCTION PROJECTS

  • Wooyong Jung;Seung Heon Han
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.534-541
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    • 2011
  • Risk evaluation approaches for bidding on international construction projects are typically partitioned into three stages: country selection, project classification, and bid-cost evaluation. However, previous studies are frequently under attack in that they have several crucial limitations: 1) a dearth of studies about country selection risk tailored for the overseas construction market at a corporate level; 2) no consideration of uncertainties for input variable per se; 3) less probabilistic approaches in estimating a range of cost variance; and 4) less inclusion of covariance impacts. This study thus suggests a three-staged risk evaluation model to resolve these inherent problems. In the first stage, a country portfolio model that maximizes the expected construction market growth rate and profit rate while decreasing market uncertainty is formulated using multi-objective genetic analysis. Following this, probabilistic approaches for screening bad projects are suggested through applying various data mining methods such as discriminant logistic regression, neural network, C5.0, and support vector machine. For the last stage, the cost overrun prediction model is simulated for determining a reasonable bid cost, while considering non-parametric distribution, effects of systematic risks, and the firm's specific capability accrued in a given country. Through the three consecutive models, this study verifies that international construction risk can be allocated, reduced, and projected to some degree, thereby contributing to sustaining stable profits and revenues in both the short-term and the long-term perspective.

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A Study on the Risk Assessment System for Human Factors (휴먼에러를 중심으로 한 위험요인 도출 방법론에 관한 연구)

  • Jung, Sang Kyo;Chang, Seong Rok
    • Journal of the Korean Society of Safety
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    • v.29 no.3
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    • pp.79-84
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    • 2014
  • Human error is one of the major contributors to the accidents. A lot of risk assessment techniques have been developed for prevention of accidents. Nevertheless, most of them were interested in physical factors, because quantitative evaluation of human errors was difficult quantitatively. According to lack of risk assessment techniques about human errors, most of industrial risk assessment for human errors were based on data of accident analysis. In order to develop an effective countermeasure to reduce the risk caused by human errors, a systematic analysis is needed. Generally, risk assessment system is composed of 5 step(classification of work activity, identification of hazards, risk estimation, evaluation and improvement). This study aimed to develop a risk identification technique for human errors that could mainly be applied to industrial fields. In this study, Ergo-HAZOP and Comprehensive Human Error Analysis Technique were used for developing the risk identification technique. In the proposed risk identification technique, Ergo-HAZOP was used for broad-brush risk identification. More critical risks were analysed by Comprehensive Human Error Analysis Technique. In order to verify applicability, the proposed risk identification technique was applied to the work of pile head cutting. As a consequence, extensive hazards were identified and fundamental countermeasures were established. It is expected that much attention would be paid to prevent accidents by human error in industrial fields since safety personnel can easily fint out hazards of human factors if utilizing the proposed risk identification technique.