• 제목/요약/키워드: risk function

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

  • 박서영;강인석;김창학;손창백
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2001년도 학술대회지
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    • pp.519-524
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    • 2001
  • 국내·외적으로 건설공사의 리스크관리에 대한 중요성은 더욱 커져가고 있지만, 합리적인 리스크인자의 구축방법과 개별 리스크인자의 분석 및 정량화가 용이하지 않기 때문에 실무적 운용이 가능한 리스크분석시스템을 구축한 경우는 극히 미흡한 실정이다. 본 연구에서는 전문가의 주관적 판단과 언어적 변량을 이용하여 리스크를 정량화하기 위한 퍼지분석방법을 제시한다. 본 퍼지분석방법은 건설공사의 리스크인자를 발생확률 발생강도, 발생빈도로 구분하여 평가하게 함으로서 그 적용성과 정확성을 높일 수 있도록 하였고, 언어적 변량을 이용하여 리스크를 정량화하기 때문에 복잡한 자료의 구축과 분석시간을 단축하였으며, 그 적용이 매우 쉽다는 장점을 갖게 된다.

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Risk Assessment in Finland: Theory and Practice

  • Anttonen, Hannu;Paakkonen, Rauno
    • Safety and Health at Work
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    • 제1권1호
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    • pp.1-10
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    • 2010
  • The Finnish risk assessment practice is based on the Occupational Safety and Health (OSH) Act aiming to improve working conditions in order maintain the employees' work ability, and to prevent occupational accidents and diseases. In practice there are hundreds of risk assessment methods in use. A simple method is used in small and medium sized enterprises and more complex risk evaluation methods in larger work places. Does the risk management function in the work places in Finland? According to our experience something more is needed. That is, understanding of common and company related benefits of risk management. The wider conclusion is that commitment for risk assessment in Finland is high enough. However, in those enterprises where OSH management was at an acceptable level or above it, there were also more varied and more successfully accomplished actions to remove or reduce the risks than in enterprises, where OSH management was in lower level. In risk assessment it is important to process active technical prevention and exact communication, increase work place attraction and increase job satisfaction and motivation. Investments in OSH are also good business. Low absenteeism due to illness or accidents increases directly the production results by improved quality and quantity of the product. In general Finnish studies have consistently shown that the return of an invested euro is three to seven-old. In national level, according to our calculations the savings could be even 20% of our gross national product.

무기체계 시험업무에 대한 리스크 관리 표준 프로세스 연구 (A Study on Standard Process of Risk Management for Defense Systems Test Works)

  • 나태흠;허동은;김영민;이주연
    • 한국군사과학기술학회지
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    • 제27권3호
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    • pp.364-374
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    • 2024
  • Today, risks created by uncertainty must be managed for successful project execution. From this perspective, applying a risk management process is very important for successful defense systems test works. This paper describes 'the implentation of risk management process for test work' carried out by DTERI's process improvement activities. In this study, the concept of risk management process, and details of the risk management process are examined through PMBOK and ISO/IEC/IEEE 15288, CMMI. After that, we defined 'Standard Process for Risk Management' of defence systems test works. And, we describe 'Risk Management Function' of DTERI's Project Management System(PMS) and the risk management process of DTERI. Finally, the effectiveness of the risk management standard process is verified through quantitative analysis.

Better Estimators of Multiple Poisson Parameters under Weighted Loss Function

  • Kim, Jai-Young
    • 한국국방경영분석학회지
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    • 제11권2호
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    • pp.69-82
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    • 1985
  • In this study, we consider the simultaneous estimation of the parameters of the distribution of p independent Poisson random variables using the weighted loss function. The relation between the estimation under the weighted loss function and the case when more than one observation is taken from some population is studied. We derive an estimator which dominates Tsui and Press's estimator when certain conditions hold. We also derive an estimator which dominates the maximum likelihood estimator(MLE) under the various loss function. The risk performances of proposed estimators are compared to that of MLE by computer simulation.

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Seismic risk assessment of intake tower in Korea using updated fragility by Bayesian inference

  • Alam, Jahangir;Kim, Dookie;Choi, Byounghan
    • Structural Engineering and Mechanics
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    • 제69권3호
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    • pp.317-326
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    • 2019
  • This research aims to assess the tight seismic risk curve of the intake tower at Geumgwang reservoir by considering the recorded historical earthquake data in the Korean Peninsula. The seismic fragility, a significant part of risk assessment, is updated by using Bayesian inference to consider the uncertainties and computational efficiency. The reservoir is one of the largest reservoirs in Korea for the supply of agricultural water. The intake tower controls the release of water from the reservoir. The seismic risk assessment of the intake tower plays an important role in the risk management of the reservoir. Site-specific seismic hazard is computed based on the four different seismic source maps of Korea. Probabilistic Seismic Hazard Analysis (PSHA) method is used to estimate the annual exceedance rate of hazard for corresponding Peak Ground Acceleration (PGA). Hazard deaggregation is shown at two customary hazard levels. Multiple dynamic analyses and a nonlinear static pushover analysis are performed for deriving fragility parameters. Thereafter, Bayesian inference with Markov Chain Monte Carlo (MCMC) is used to update the fragility parameters by integrating the results of the analyses. This study proves to reduce the uncertainties associated with fragility and risk curve, and to increase significant statistical and computational efficiency. The range of seismic risk curve of the intake tower is extracted for the reservoir site by considering four different source models and updated fragility function, which can be effectively used for the risk management and mitigation of reservoir.

The Relationship between Alcohol Consumption and Diabetes in Korean Adults

  • Gi Tae Kim;Jae Woong Sull
    • 대한의생명과학회지
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    • 제29권3호
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    • pp.159-167
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    • 2023
  • The prevalence of diabetes continues to increase worldwide, and the problem is also important in Korea, and about 14% of Korean adults have diabetes. Alcohol consumptions are increasing rapidly around the world and are recognized as one of the major problems in the country. Alcohol consumption is an environmental factor previously known to be associated with the risk of developing diabetes. Alcohol consumption can cause problems in the endocrine system and gastrointestinal function, and oxidative stress of acetaldehyde, an ethanol metabolite, can damage beta cells in the pancreas. In the present study, we found the effect of alcohol intake on fasting blood sugar and the difference between men and women in the risk of diabetes according to alcohol intake. In men, the high-drinking group had a higher risk of diabetes than the non-drinking group (OR, 1.41; P=0.058). In women, the Moderate-drinking group had a lower risk of diabetes compared to the non-drinking group (OR, 0.42; P=0.039). The high-drinking group had a higher risk of diabetes than the non-drinking group (OR, 2.97; P=0.034). The group that consumed more than the WHO's daily alcohol intake risk standard tended to have a higher risk of diabetes than the group that did not (OR, 5.48; P=0.001). This study suggest that moderate alcohol consumption reduce the risk of developing diabetes, and high alcohol consumption increase the risk of developing diabetes.

Poisson분포를 이용한 도시가스 화재 폭발사고의 발생 예측프로그램 및 사회적 위험기준에 관한 연구 (Study on Predictable Program of Fire.Explosion Accident Using Poisson Distribution Function & Societal Risk Criteria in City Gas)

  • 고재선;김효;이수경
    • 한국화재소방학회논문지
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    • 제20권1호
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    • pp.6-14
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    • 2006
  • 가스로 인한 화재 및 폭발사고의 예측 가능한 프로그램을 구체화하고, 적절한 사회적 위험기준을 제시하기 위하여 최근 11년간의 가스사고 데이터베이스를 분석하였다. 먼저 동일유형의 가스사고 발생가능 성을 판단할 수 있는 Poisson 분석 방법을 적용하기 위해 3개의 사고유형, 즉 누출, 폭발, 화재로 구분하여 총 16개 항목으로 나누어서 적용하였다. 그 결과, 시공 작업 부주의-폭발-배관의 항목의 사고발생반도가 가장 작았으며, 배관연결부이완부식-누출-배관의 경우는 가장 높은 빈도를 나타내었다. 따라서 이에 대한 적절한 가스사고 대응책이 마련되어야 할 것이다. 또한 치명적인 가스사고의 추세와 합리적인 위험정책에 대한 지침을 결정하기위해 D. O. Hagon 방정식과 회기직선식을 이용하여 F.N 곡선의 누적사망자의 최소 및 최대점에 대응시켜 허용가능영역을 설정하였다. 향후 가스사고에 대한 신뢰성 있는 분석을 위해서는 가스로 인한 화재 폭발사고에 대한 데이터베이스를 지속적으로 확충보완을 시켜야 되며, 이를 위한 표준 코드화 작업이 요구된다.

Safety analysis to derive safety requirement in the railway system

  • Joung, Eui-Jin;Shin, Kyung-Ho;Kim, Yong-Gyu
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.383-386
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    • 2006
  • The safety of the railway system is important because the system is a mass transit system and the results of the accident are inconceivable. The railway system is operated by train operation system such as train control system. So the train control system requires safety critical characteristics. In the European railway, ETCS (European Train Control System) project has been finished to accomplish the interoperability of each national railway signaling system. According to the interoperability degree, ETCS levels are suggested. As the highest level, ETCS level 3 suggests a radio communication. Also recently urban railway system is operated by driverless and automatic train control system. In this circumstance, more safety is required than before in the railway system. In order to accomplish the safety of a system, the requirements considering safety have to be suggested. The requirement is a set of several functions such as general function, environment, safety etc. For the safety critical system, safety function is more important than any other functions. The safety functions are deduced by safety analysis. In order to perform the safety analysis, the system hazards have to be identified and then risk analysis for each hazard should be performed. The risk is related to the frequency and the severity of each hazard. And then countermeasures for each risk have to be prepared. The summary of the countermeasures is about a kind of safety functions in a system. In this paper, the safety functions for a train control system are presented according to the above procedure.

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주관적 기억감퇴를 가진 노인에서 백질 변화와 인지기능 장애의 관련성 (Relationship between White Matter Changes and Cognitive Dysfunction in the Elderly with Subjective Memory Complaint)

  • 신은영;정한용;김양래;이소영;김신겸
    • 생물정신의학
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    • 제18권3호
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    • pp.141-147
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    • 2011
  • Objectives The purpose of this study is to evaluate the relationship between the severity of white matter changes (WMC), risk factors and cognitive domains, including executive function profiles. Method Forty nine subjects over 55 years with subjective memory complaints were assessed with MRI and neuropsychological tests. The WMC were assessed by MRI T2-FLAIR images and divided into 3 groups of mild vs. moderate vs. severe and 2 groups of mild-moderate vs. severe by using Mantyla's criteria and Fazeka's criteria. The risk factors were examined in hypertension, heart disease history and chemistry Lab. Medical conditions which affect to cognitive dysfunction and definite dementia were also excluded. Results Comparing 3 groups, hypertension was identified as a risk factor of the WMC. Comparing 2 groups, total cholesterol and LDL were identified for as the risk factor of WMC. The severity of WMC was significantly associated with cognitive disturbances and their main effect on cognition was working memory and inhibition. Conclusion The risk factors of the WMC in the elderly were hypertension, hyperlipidemia. The severity of WMC appears to be associated with executive dysfunction in the elderly.

구매가격 변동시 위험을 고려한 재고모형 (Risk-averse Inventory Model under Fluctuating Purchase Prices)

  • 유석천;박찬규;정욱
    • 한국경영과학회지
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    • 제35권4호
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    • pp.33-53
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    • 2010
  • When purchase prices of a raw material fluctuate over time, the total purchasing cost is mainly affected by reordering time. Existing researches focus on deciding the right time when the demand for each period is replenished at the lowest cost. However, the decision is based on expected future prices which usually turn out to include some error. This discrepancy between expected prices and actual prices deteriorates the performance of inventory models dealing with fluctuating purchase prices. In this paper, we propose a new inventory model which incorporates not only cost but also risk into making up a replenishment schedule to meet each period's demand. For each replenishment schedule, the risk is defined to be the variance of its total cost. By introducing the risk into the objective function, the variability of the total cost can be mitigated, and eventually more stable replenishment schedule will be obtained. According to experimental results from crude oil inventory management, the proposed model showed better performance over other models in respect of variability and cost.