• Membrane and Water Treatment
• /
• 제8권2호
• /
• pp.137-147
• /
• 2017

A water treatment utility in South Korea operates a large system of pressurized hollow fiber membrane (PHFM) modules. The optimal selection of membrane module for the full scale plant was critical issue and carried out using Risk-based Life Cycle Cost (RbLCC) analysis based on the historical data of operation and maintenance. The RbLCC analysis was used in the process of decision-making for replacing aged modules. The initial purchasing cost and the value at risk during operation were considered together. The failure of modules occurs stochastically depending on the physical deterioration with usage over time. The life span of module was used as a factor for the failure of Poisson's probability model, which was used to obtain the probability of failure during the operation. The RbLCC was calculated by combining the initial cost and the value at risk without its warranty term. Additionally, the properties of membrane were considered to select the optimum product. Results showed that the module's life span in the system was ten years (120 month) with safety factor. The optimum product was selected from six candidates membrane for a full scale water treatment facility. This method could be used to make the optimum and rational decision for the operation of membrane water purification facility.

• 한국건축시공학회지
• /
• 제19권5호
• /
• pp.439-448
• /
• 2019

아파트 프로젝트는 사업성패에 영향을 미치는 요인은 매우 다양하다. 그러나 분양단가가 결정되고, 분양이 시작된 이후에는 사업에 가장 큰 영향을 미치는 요인은 분양 후 1개월간의 초기분양률이다. 일반적으로 사업주체는 경제상황, 주택시장의 동향, 사업지 인근의 주택가격 등 다양한 자료에 의해 초기분양률을 예측한다. 그러나 이러한 요인들을 초기분양률과 연계하여 정량적으로 계산하는 것은 매우 어렵다. 따라서 본 연구는 실제 수행된 아파트 프로젝트의 분양결과 자료를 이용하여 초기분양률 예측 회귀모델을 제안하는 것을 목적으로 한다. 본 연구를 위해 기존 분양실적자료 수집, 영향요인들의 상관관계 분석, 초기분양률 예측 회귀모델 작성을 진행한다. 본 연구의 결과는 아파트 프로젝트의 사업성 분석 시 초기 분양률 예측을 위한 기초자료로 활용되며, 사업 리스크 모델 개발의 핵심 자료로 활용된다.

• 산업기술연구
• /
• 제25권B호
• /
• pp.99-106
• /
• 2005

The planning phase of construction project success or failure of the enterprise decision the 1st dangerous duration which occurs very there is a possibility of making with the phase which is important, of construction project in life cycle most many risk. But the risk management from planning phase well does not become accomplished is the actual condition from existing construction project. Consequently, it classifies the risk event from project initial planning phase of construction project from this study which probably is substantial risk event the possibility of accomplishing from a planning phase successfully in order to be.

• 한국안전학회지
• /
• 제35권2호
• /
• pp.61-66
• /
• 2020

As asbestos-containing buildings are getting older, asbestos deconstruction works are increasing. As a result, accident risks such as falls, cuts, electric shocks, and suffocation are increasing. Existing studies are mostly about health management and institutional policy research and there is little research on work risk. So workplace risk assessments that are easily applicable in the field are required to be applied. Sealing is the first process of asbestos deconstruction and is the first step to ensure worker's safety. Job Safety Analysis(JSA) and Checklist were used to identify the risk factors and to calculate the level of the risk. By comparing the two risk assessment tools, it was figured out that the JSA is appropriate for the initial process and change of work procedure while Checklist is appropriate for repetitive work. Because the sealing process is sort and simple, it is unlikely to cause serious injury. But since the risk of falling and cuts are exist, safety education and supervision are necessary to maintain a safe working environment.

• 대한수학회보
• /
• 제48권2호
• /
• pp.325-334
• /
• 2011

In this paper we consider the discrete time delayed renewal risk model. We investigate what will happen when the distribution function of the discounted proper deficit is asymptotic in the initial surplus. In doing this we establish several lemmas regarding some related ruin quantities in the discrete time delayed renewal risk model, which are of significance on their own right.

• 한국항해항만학회지
• /
• 제38권4호
• /
• pp.327-333
• /
• 2014

해상에서의 충돌사고 예방을 위한 충돌회피 원칙 및 각종 항법 등을 규정하고 있는 국제해상충돌예방규칙은 선박 간 충돌회피를 위한 초기대응 기준에 대해 대부분 선박 운항자 경험 및 주관적 판단에 의해 결정하도록 명시되어 있다. 그러나 초임 해기사나 학생들은 선박 운항 환경을 종합적으로 판단할 수 있는 경험 및 능력이 부족하므로, 충돌방지를 위한 최소한의 정량적인 초동조치 기준을 제시해 줌으로써 충돌사고를 효과적으로 예방할 수 있을 것으로 사료된다. 본 연구에서는 해상충돌예방규칙 및 기존 충돌위험 관련 연구 동향을 분석하였으며, 다양한 승선경력을 가진 선박 운항자들을 대상으로 설문을 실시하여 선박 간 조우관계에 따라 주관적으로 판단하는 최소 안전 이격거리와 초기대응의 개시 거리 및 변침각도를 조사하였다. 이러한 분석 결과를 기초로 선박 조우 관계별 충돌회피를 위한 초기 동작이 필요한 거리, 안전 이격거리 및 변침각도를 제시한다. 초기대응 기준은 해양사고 예방뿐만 아니라 점진적인 운항 기술의 향상에 기여할 것이다.

• 대한임상독성학회지
• /
• 제18권1호
• /
• pp.34-41
• /
• 2020

Purpose: This study evaluated aggressive hyperbaric oxygen therapy (HBOT) by understanding various exposure routes of acute carbon monoxide (CO) poisoning, the risk factors causing acute cardiovascular, and neurological toxicity caused by poisoning. Methods: A retrospective study was conducted based on the medical records of 417 acute CO poisoning patients who visited the emergency care unit from March 2017 to August 2019. The exposure routes, HBOT performance, age, sex, medical history (hypertension, diabetes mellitus, ischemic heart disease, heart failure), intentionality, loss of consciousness (LOC), intake with alcohol or sedatives, and initial test results (carboxyhemoglobin (COHb), troponin-I, electrocardiography, echocardiography, brain MRI) were examined. Comparative analysis of the clinical information was conducted between the groups that showed acute cardiovascular toxicity and neurological toxicity, and groups that did not. Results: Among 417 patients diagnosed with acute CO poisoning, 201 cases (48.2%) were intentional, and charcoal briquette was the most common route (169 patients (40.5%)). Two hundred sixteen cases (51.8%) were accidental, and fire was the most common route (135 patients (32.4%)). The exposure route was more diverse with accidental poisoning. Three hundred ninety-nine patients were studied for acute cardiovascular toxicity, and 62 patients (15.5%) were confirmed to be positive. The result was statistically significant in intentionality, LOC, combined sedatives, initial COHb, HTN, and IHD. One hundred two patients were studied for acute neurological toxicity, which was observed in 26 patients (25.5%). The result was statistically significant in age and LOC. Conclusion: Active HBOT should be performed to minimize damage to the major organs by identifying the various exposure routes of CO poisoning, risk factors for acute cardiovascular toxicity (intentionality, LOC, combined sedatives, initial COHb, HTN, IHD), and the risk factors for acute neurological toxicity (age, LOC).

• 한국안전학회지
• /
• 제31권5호
• /
• pp.141-148
• /
• 2016

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. Especially, in case of the SIL allocation method without determining of quantitative tolerable risk, the additional review is needed to check whether it is suitable or not is required. In this study, the quantitative risk reduction model based on the safety integrity allocation results of railway platform screen door system using Risk Graph method has been examined in order to review the suitability of quantitative risk reduction according to allocated safety integrity level.

• 해양환경안전학회지
• /
• 제22권3호
• /
• pp.259-267
• /
• 2016

The study performs a risk analysis on container ship accidents using accident data collected over the six years from 2006 to 2011, presents the resulting risk level, and suggests three risk mitigation measures to reduce the overall risk, for the safer operation of container ships. More specifically, starting from the initial accident of collision, we developed 13 different accident scenarios using event tree analysis based on which the overall risk level was obtained and presented as a FN curve. Since diverse human factors are the main cause of most of the ship accidents, our study focuses on the effect of reducing human causes on the resulting risk level. For the research we considered the injuries for the calculation of fatality with the help of MAIS. The results show that collision was the main type of accident, accounting for 62 % of all accidents, and the measures employed were proven to be effective in the sense that the risk level was much lowered and the average number of fatalities was also reduced. With more data accumulated, more precise risk level will be calculated with which the practical risk mitigating measures will be also developed. For future study, economic loss and environmental damage as consequences need to be considered.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.451-458
• /
• 2013

This research documents the initial findings and recommendations for developing a risk management tool to assess and quantify the risks associated with the construction of the next generation of nuclear power plants. The proposed tool builds upon the Construction Industry Institute's International Project Risk Assessment (IPRA) Best Practice. This paper provides an overview of the investigation to assess the unique risk elements pertaining to nuclear power plant construction and documents the preliminary findings from historical project performance data to better understand the function and use of the IPRA's Relative Impact value.