• Nuclear Engineering and Technology
• /
• 제33권6호
• /
• pp.596-604
• /
• 2001

This paper quantitatively presents the effects of important factors of the probabilistic safety assessment (PSA) of safety-critical digital systems. The result which is quantified using fault tree analysis methodology shows that these factors remarkably affect the system safety. In this paper we list the factors which should be represented by the model for PSA. Based on the PSA experience, we select three important factors which are expected to dominate the system unavailability. They are the avoidance of common cause failure, the coverage of fault tolerant mechanisms and software failure probability. We Quantitatively demonstrate the effect of these three factors. The broader usage of digital equipment in nuclear power plants gives rise to the safety problems. Even though conventional PSA methods are immature for applying to microprocessor-based digital systems, practical needs force us to apply it because the result of PSA plays an important role in proving the safety of a designed system. We expect the analysis result to provide valuable feedback to the designers of digital safety- critical systems.

• 한국항공운항학회지
• /
• 제25권4호
• /
• pp.195-203
• /
• 2017

Around 70% of domestic aircraft accidents in helicopter aircraft. The causal factors of the helicopter accidents are identified as human factors. People have focused mostly on unsafe acts to prevent the accident. The accidents should be analysed on human factors to reduce accident. The unsafe acts can be managed effectively if the latent failures were identified through the HFACS. This paper is to introduce about the latent failure classified by the HFACS and provide the analysis regarding the latent failure of the helicopters by the aviation safety advisors through the interviews.

• 벤처창업연구
• /
• 제12권1호
• /
• pp.25-31
• /
• 2017

본 연구는 벤처기업의 부실요인을 파악한 것이다. 이를 위해 기술보증기금에서 기술보증을 받은 벤처기업 중 최근 3개년 간 보증사고가 발생한 210개 기업을 대상으로 한 사례분석을 통하여 부실사유를 분석하였다. 부실사유 분석방법은 다음과 같다. 우선 기업의 재무자료를 활용하여 성장성과 수익성을 기준으로 4개의 유형을 분류하였다. 이후 사고기업의 보증사고발생보고서를 토대로 부실요인을 분석하였다. 보증사고발생보고서란 보증사고가 발생하면 기보에서 직접 기업을 방문하여 그 부실이 이르게 된 원인이나 향후 재기 가능성을 파악한 보고서이다. 분석결과, 374건의 부실요인들이 도출되었으며 벤처기업들이 부실화되어 사업실패에 이르는 가장 큰 이유로 관련 산업 또는 전반적인 경기악화(79건), 주요 납품처의 계획변경, 도산 등으로 수주 감소 취소(54건), 매출채권회수부진(31건), 가격경쟁, 주요 납품처의 요구 등에 따른 제품가격 동결 하락(24건), 국내 또는 해외 원자재의 가격 상승(21건) 등의 순으로 나타났다. 또한 본 연구에서 새롭게 도출된 부실요인으로 앞에서 주기로 표시한 주요 납품처와 관련된 Risk가 있으며 그 외에 일본원전 사고 개성공단 가동중단 소송 등 돌발 악재 발생, 기술개발사업화의 지연, 비효율적 관리로 고비용 저효율 구조 등이 있다.

• 한국지반공학회논문집
• /
• 제18권2호
• /
• pp.23-37
• /
• 2002

절취 사면에서의 파괴는 사면의 내부 또는 외부 요인들의 결합에 의해 발생한다. 내부 요인은 사면 자체의 지질 또는 형상 조건과 관련된 파괴 요인이며, 외부 요인은 자연적 또는 인위적으로 사면에 가해지는 파괴 요인이다. 각 요인에 의한 사면 파괴에 기치는 영향의 정도는 사면을 구성하는 지반 조건에 따라 다르며, 사면의 거동 특성에 의해 제어된다. 이 연구에서는 사면의 지반 조건을 거동 특성에 따라 구분하는 기준으로 토층심도율(SR), 블록크기비(BR) 및 암석강도를 사용하였다. 이런 기준에 의하면 사면의 지반 조건은 불연속체적 절리 암반과 연속체적 토상 지반, 파쇄 암반, 괴상 암반으로 구분된다. SFi-system은 이와 같이 구분된 지반 조건에 따라 내부 파괴 요인과 외부 파괴 요인을 평가함으로써 사면 파괴 지수(SFi)를 결정하는 평가 시스템이다. 이 평가 시스템을 실제적으로 사면에 적용한 결과, 사면 파괴 지수는 사면 파괴의 가능성 및 규모와 밀접한 관련이 있음을 보여준다. 따라서 SFi-system은 사면의 파괴 예측과 그 특성 분석을 위한 효과적인 도구로 사용될 수 있다.

• 한국초등과학교육학회지:초등과학교육
• /
• 제36권4호
• /
• pp.439-446
• /
• 2017

The purpose of this study was to compare Grit, failure tolerance and psychological well-being between elementary science gifted and general students. The subjects of this study were 48 science gifted students and 70 general students in the 5th and 6th grade of elementary school in Gyeonggi province. The results of this study were as follows: First, Grit, failure tolerance and psychological well-being of science gifted students were higher than those of the general students, there was a statistically significant difference. Second, science gifted students showed higher correlation between grit and failure tolerance, grit and psychological well-being than general students. Grit of science gifted students had a positive correlation with all sub-factors of academic failure tolerance and psychological well-being. In general students, there was a positive correlation with all sub-factors of Grit, academic failure tolerance, and psychological well-being except for the emotion sub-factor of academic failure tolerance. Thirdly, as a result of the regression analysis on the elements of failure tolerance affecting the Grit, science gifted students showed emotional factor but general students had behavioral factors. Also, as a sub-factor of psychological well-being on Grit, both science gifted and general students showed autonomy.

• 성인간호학회지
• /
• 제27권2호
• /
• pp.242-250
• /
• 2015

Purpose: To evaluate heart failure knowledge and adherence to self-care behaviors, and to identify factors affecting adherence to self-care behaviors among Korean patients with heart failure. Methods: Correlational research using the European Heart Failure Self-care Behavior Scale, the Duke Activity Status Index, the Dutch Heart Failure Knowledge Scale, the New York Heart Association Functional Classification, and the Medical Outcomes Study Social Support Survey was conducted. A total of 280 outpatients with heart failure responded to the five questionnaires. Results: The mean scores for self-care adherence and heart failure knowledge were $31.98{\pm}6.81$ and $8.78{\pm}2.53$, respectively, indicating lower adherence and knowledge than those previously reported. Subjects with lower functional status, more social supports, and greater knowledge of heart failure are more likely to adhere to prescribed regimens. Conclusion: Nurses should focus on patient education and support to improve their adherence to self-care behaviors.

• Journal of Korean Neurosurgical Society
• /
• 제61권3호
• /
• pp.415-423
• /
• 2018

Objective : To identify the perioperative factors associated with instrument failure in patients undergoing a partial corpectomy with instrumentation (PCI) for spinal metastasis. Methods : We assessed the one hundred twenty-four patients with who underwent PCI for a metastatic spine from 1987 to 2011. Outcome measure was the risk factor related to implantation failure. The preoperative factors analyzed were age, sex, ambulation, American Spinal Injury Association grade, bone mineral density, use of steroid, primary tumor site, number of vertebrae with metastasis, extra-bone metastasis, preoperative adjuvant chemotherapy, and preoperative spinal radiotherapy. The intraoperative factors were the number of fixed vertebrae, fixation in osteolytic vertebrae, bone grafting, and type of surgical approach. The postoperative factors included postoperative adjuvant chemotherapy and spinal radiotherapy. This study was supported by the National Research Foundation grant funded by government. There were no study-specific biases related to conflicts of interest. Results : There were 15 instrumentation failures (15/124, 12.1%). Preoperative ambulatory status and primary tumor site were not significantly related to the development of implant failure. There were no significant associations between insertion of a bone graft into the partial corpectomy site and instrumentation failure. The preoperative and operative factors analyzed were not significantly related to instrumentation failure. In univariable and multivariable analyses, postoperative spinal radiotherapy was the only significant variable related to instrumentation failure (p=0.049 and 0.050, respectively). Conclusion : When performing PCI in patients with spinal metastasis followed by postoperative spinal radiotherapy, the surgeon may consider the possibility of instrumentation failure and find other strategies for augmentation than the use of a bone graft for fusion.

• 지식경영연구
• /
• 제15권3호
• /
• pp.1-12
• /
• 2014

It is tried to draw the failure traits of leadership by extracting leadership parts from previous failure studies and including some parts which mention failure leadership among leadership-related books. All of 5 patterns are drawn through total 13 types of study data. From 'insensitive to change' and authoritarianism which is mentioned 8 times in such 13 studies, to 'interpersonal problem', which is mentioned five times, traits which are mentioned at least five times are selected. There are drawn 5 traits including ${\Delta}$ authoritarianism ${\Delta}insensitive$ to change ${\Delta}lack$ of executive ability ${\Delta}populism$ and ${\Delta}interpersonal$ problem. As being examined in these 5 types of failure traits, the failure of leadership is ultimately happened because of communication heading for the inside without any communication(exchange) to the outside. That is, it is understood that authoritarian leaders don't perceive change correctly but make a wrong communication (populism) or break down communication. Additionally, the executive ability is to perform actually one's idea and to be achieved through incessant communication with members. Compared with other various studies to draw failure factors, these leadership traits have something in common. In the previous researches conducted the study of general failure factors, ${\Delta}adherence$ to preexisting business and resistance to change ${\Delta}unfeasible$ expansion strategy ${\Delta}blind$ faith in successful technology and innovation and ${\Delta}insufficiency$ to grasp competitor(consumer) are pointed out as the failure factors. It is deemed that these are happened because organizational management is headed for the inside without any communication (exchange) to the external environments. Matters unfolded through this paper until now are an attempt to apply the failure knowledge to a leadership part which is an individual field in business administration. It is considered that this study will be complemented through additional case study or quantitative analysis in the future.

• 정보과학회 논문지
• /
• 제42권4호
• /
• pp.468-474
• /
• 2015

기업은 프로젝트의 중요성을 인지하고 프로젝트의 실패요인을 찾아 위험을 미연에 방지하여 프로젝트의 성공율을 높이기 위해 노력해야 한다. 이것은 급변하는 외부의 변화에 신속히 대응하기 위해 필요하다. 선행연구에서도 이러한 프로젝트의 성공요인 및 실패요인에 대한 연구가 다양하게 수행되었으나, 대부분 설문조사와 샘플링 통계분석으로 연구가 수행되어 데이터의 객관성과 정량적 분석에 한계를 갖고 있었다. 따라서 본 연구에서는 프로젝트의 실패요인 분석을 객관적인 프로젝트의 평가보고서인 감리결과보고서에서 프로젝트의 문제를 발견하고 개선권고사항을 제시하는 부분의 텍스트를 도출하여 텍스트 마이닝을 수행하였다. 텍스트 마이닝에 적용한 알고리즘은 분류 성능이 우수한 NaiveBayes, SMO, J48 알고리즘이다. 실험은 10배 교차검증을 수행하였고 정확률과 재현율로 평가하였다. 도출된 텍스트에서 프로젝트의 실패요인을 분석하여 프로젝트 수행에 활용될 수 있도록 하였다.

• 한국IT서비스학회지
• /
• 제6권3호
• /
• pp.251-272
• /
• 2007

Although Enterprise Systems (ES) have promised major strategic benefits and process improvements from business and technology integration, their implementation has been plagued by a high failure rate and difficulty in realizing the promised benefits. For the purpose of understanding implementation failures, previous studies have focused on identifying critical success factors (CSFs) for information systems implementation. However, there has been little research on how these CSFs actually lead to successful results. In this study, based on process theory, we examined the process of ES implementation by explaining how the factors of ES implementation influence each other and how interaction among them produces results. Based on a failure case, we then developed a process model of ES implementation thus allowing us to explain the process of ES implementation. The proposed model facilitated an understanding of how repeating patterns of ES failure can be reversed. This model can be used for guiding new ES implementation projects.