• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권6호
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• pp.2118-2138
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• 2014

Risks are involved in all phases of the software life cycle, and due to these risks, software can face various problems that can cause different negative outcomes and sometimes, in extreme cases, the failure of the software. Most of these risks lie in the legacy software migration process. These risks can create many problems, and in the worst case they can lead to the failure of the migration project. This paper explores different types of risk analysis methods such as CRAMM, CORAS, OCTAVE and VECTOR. After comparing these methods, the two suitable methods were chosen, namely, OCTAVE and VECTOR. Based on the use of these two methods, the project suggests an enhanced EOV method for risk analysis in the migration of legacy software.

• 대한안전경영과학회지
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• 제9권1호
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• pp.65-76
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• 2007

The likelihood of failure for the stress corrosion cracking (SCC) of caustic cracking, which affect to a risk of facilities, was analyzed through the risk based-inspection using API-581 BRD. We found that SCC of the caustic cracking was occurred above 5 % NaOH concentration, and the technical module subfactor (TMSF) was maximized for above 50 % concentration. The heat traced and monitoring were not sensitive to the TMSF with NaOH concentration and temperature. But the steam out was more of less affect minimum value of the TMSF. Also, the inspection number, the inspection effectiveness, and the year since inspection were very sensitive to the TMSF with NaOH concentration and temperature. Therefore, the plan of next inspection will be established with compositively considering those at once.

• 한국가스학회지
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• 제12권2호
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• pp.25-31
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• 2008

최근 들어 도시가스사업자들이 안전관리의 수준을 더욱 향상시키기 위하여 정량적 평가(Quantitative assessment)에 기초한 위험 관리(risk management)를 많이 고려하고 있는 상황이다. 이 논문은 천연가스 배관의 정량적 위험평가의 절차에 초점을 맞췄으며, 이를 위하여 European Gas Pipeline Incident Data Group과 BG Transco의 자료를 사용한 사고발생빈도의 계산방법, 화재에 의한 사고피해영향 분석방법, 개인적 위험(Individual Risk)과 사회적 위험(Societal Risk)의 계산 방법을 체계적으로 제시하였다. 또한 국내 집단 에너지공급사업용 고압배관의 시범적용을 통하여 개인적 위험과 사회적 위험 기준을 제시하였다. 제시된 정량적 위험평가 절차는 고압배관 설계, 시공 및 변경 등의 위험관리에 유용할 것으로 판단된다.

• 대한안전경영과학회지
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• 제8권2호
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• pp.61-70
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• 2006

The likelihood of failure by the corrosion of high temperature $H_2S/H_2$, which affect to a risk of facilities, was analyzed through the risk based-inspection using API-581 BRD. We found that the corrosion rate was increased as temperature and $H_2S$ concentration were increased. Also, the technical module subfactor(TMSF) was increased as an used you increased, material thickness decreased, inspection number decreased, and inspection effectiveness increased. In these conditions, the maximum value of TMSF was not varied, but the TMSF was sensitively varied at low temperature for high concentration of $H_2S$.

• 한국지능시스템학회논문지
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• 제25권2호
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• pp.174-179
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• 2015

동적 위치제어 시스템(Dynamic Positioning System)의 위험성과 신뢰성 평가에 FMEA(Failure Mode and Effect Analysis)를 적용하고 있으나, 해양 프로젝트가 가진 특징으로 인해 다음과 같은 한계를 가진다. 1) SCADA(Supervisory Control and Data Acquisition) 시스템을 통해 수집되는 고장 데이터의 일부는 환경의 영향으로 인한 오작동이나 단순한 센서고장으로 인해 생성되는 데이터를 포함하고 있으므로 불완전하고 신뢰할 수 없다. 따라서, FMEA의 세 가지 변수인 심각도(Severity), 발생빈도(Occurrence), 검출빈도(Detection)의 평가는 전문가 지식에 근거한다. 2) 전문가들의 주관적인 판단에 전적으로 의존할 경우 위험 요소들을 정밀하게 평가하기 어렵다. 3) 위험 요소들 사이의 상대적인 중요도는 고려되지 않아 위험우선순위가 명료하게 표현되지 않는다. 4) 서로 다른 고장모드에 대해 동일한 위험 우선순위 값을 가질 경우 상대적인 중요도를 판단하기 어렵다. 이러한 문제점을 극복하고 기존의 FMEA의 효과를 높이기 위해, Fuzzy-FMEA를 제안하고, 선박/해양 프로젝트의 동적 위치제어 시스템의 FMEA 문서에 적용하였다. 본 논문은 DP FMEA, DP FMEA 입증 시험서(DP FMEA Proving Trials)에 나타낸 전문가 지식을 퍼지 모델로 구현하여 FMEA 위험우선순위(RPN; Risk Priority Number)에 위험요소들의 상대적인 중요성을 포함시켰다. 제안한 방법은 해양 프로젝트의 동적 위치제어 시스템의 기계 및 전장 장비에 적용하여 기존의 FMEA와 비교하였다.

• Industrial Engineering and Management Systems
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• 제14권4호
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• pp.379-391
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• 2015

Several risk assessment techniques have been presented and investigated in previous research, focusing mainly on the failure mode and effect analysis (FMEA). FMEA can be employed to determine where failures can occur within industrial systems and to assess the impact of such failures. This research proposes a novel methodology for hazard analysis and risk assessments that integrates FMEA with the bow-tie model. The proposed method has been applied and evaluated in a real industrial process, illustrating the effectiveness of the proposed method. Specifically, the bowtie diagram of the critical equipment in the adopted plant in the case study was built. Safety critical barriers are identified and each of these is assigned to industrial process with an individual responsible. The detection rating to the failure mode and the values of risk priority number (RPN) are calculated. The analysis shows the high values of RPN are 500 and 490 in this process. A global corrective actions are suggested to improve the RPN measure. Further managerial insights have been provided.

• Archives of Pharmacal Research
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• 제10권4호
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• pp.245-249
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• 1987

Cardiovascular disease is at present the leading cause of deth in the United States and other in dustrilized countries. A major contributing factor of cardiovascular disease is essential hypertension. Untreated, essential hypertension is considered a risk factor for sudden death due to myocardial infarctions, as well as a risk factor for cerebral vascular disease, renal failure and congestive heart failure. During the last decade, significant progress has been made in the basic knowledge of the pathogenesis of hypertension as well as in the development of new antihypertensive drugs.

• 대한족부족관절학회지
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• 제23권1호
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• pp.18-23
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• 2019

Purpose: This study compared and analyzed the risk factors that affect a wound healing group and healing failure group. Materials and Methods: From 2010 to 2018, 39 patients who had suffered a single toe amputation were evaluated retrospectively. The patients were divided into two groups (wound healing group and healing failure group - within at least 3 months following the amputation). Regarding the possible risk factors, age, gender, Wagner and Brodsky classifications, duration of diabetes mellitus, whether the patient had peripheral arterial occlusive disease (PAOD) or cardiovascular disease, body mass index, HbA1c, total cholesterol, estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), smoking, and alcohol were investigated. Results: The mean duration of diabetes mellitus was 140 months in the healing group and 227 months in the healing failure group, and the duration of diabetes was significantly longer in the failure group (p=0.009). A significant difference in eGFR was observed between the two groups ($59.17mL/min/1.73m^2$ in the healing group and $31.1mL/min/1.73m^2$ in the failure group) (p=0.022). Sixteen patients with PAOD were found, all 10 patients in the healing failure group were PAOD patients. Conclusion: To reduce the additional complications in single toe amputation patients, the underlying disease and appropriate treatment are the most important factors. In addition, a more proximal level of amputation also should be considered in cases of patients with PAOD, high BUN and low eGFR, and patients with long-term diabetes.

• 한국농공학회지
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• 제28권3호
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• pp.69-78
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• 1986

This studies were established to find out the characteristics of frequency distributiom for the number of occurrence and magnitude, probable flood flows according to the return periods, design floods, and design frequency factors for the studying basins in relation to the risk levels which can be correlated with design return period and the life of structure in the non-annual exceedance series. Eight watersheds along Han, Geum, Nak Dong and Seom Jin river basin were selected as studying basins. The results were analyzed and summarized as follows. 1. Poisson distribution and Exponential distribution were tested as a good fitted distributions for the number of occurrence and magnitude for exceedance event, respectively,at selected watersheds along Han, Geum, Nak Dong and Seom Jin river basin. 2.Formulas for the probable flood flows and probable flood flows according to the return periods were derivated for the exponential distribution at the selected watersheds along Han, Geum, Nak Dong, and Seom Jin river basin. 3.Analysis for the risk of failure was connected return period with design life of structure in the non-annual exceedance series. 4.Empirical formulas for the design frequency factors were derivated from under the condition of the return periods identify with the life of structure in relation to the different risk levels in the non-annual exceedance series. 5.Design freguency factors were appeared to be increased in proportion to the return periods while those are in inverse proportion to the levels of the risk of failure. Numerical values for the design frequency factors for the non-annual exceedance series ware appeared generally higher than those of annual maximum series already published by the first report. 6. Design floods according to the different risk levels could be derivated by using of formulas of the design frequency factors for all studying watersheds in the nor-annual exceedance series.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.569-581
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• 2020

Since the dehydration packages of offshore plant deal directly with oil & gas, there is a great risk of fire and explosion during operation. Therefore, this study performed risk assessment through HAZard & OPerability (HAZOP) for solid desiccant dehydration package that can remove water component of natural gas in offshore floating liquefied natural gas (LNG) production facilities below 0.1 ppmv. The risk matrix was determined by dividing the likelihood and the severity into five levels separately by asset, life, environment and reputation. The piping & instrumentation diagram (P&ID) of the dehydration package was divided into 9 nodes. Total 22 deviations were assessed in consideration of the adsorption and desorption conversion cycle. A risk assessment based on deviations revealed 14 major hazards. Three representative types of hazards were open/close failure of the control valve, control failure of the heater, and abnormal operation of the regeneration gas cooler. Finally, we proposed the installation of additional safety devices to improve safety against these major hazards, such as safety instrumented functions, alarms, etc.