• 한국지반공학회논문집
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• 제15권4호
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• pp.167-173
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• 1999

본 논문에서는 전면부 변형형태에 따른 보강토옹벽의 파괴거동을 탄소봉 모형 실험장치를 이용하여 실험적으로 연구하였다. 실험에서는 모형 보강토 벽체의 전면판 변형 형태를 상부변형, 수평변형, 하부변형 등 3종류로 나누어 실시하였다. 변형된 벽체의 파괴선을 육안으로 확인하기 위하여 사진촬영 기법을 이용하였다. 실험결과 상부변형의 조건일 경우 파괴선은 포물선의 형태를,수평이동의 조건일 경우 파괴선은 매우 큰 원호의 형태를 보였으며, 하부변형의 조건일 경우 파괴선은 직선화된 대수나선형태를 보였다. 현재 설계에 많이 사용되고 있는 복합중력식 설계법의 가상파괴선은 하부변형 조건의 파괴선과 가장 유사한 형태를 보였다.

• 대한안전경영과학회지
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• 제3권2호
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• pp.113-121
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• 2001

Today, facilities are composed of many complex components or parts. Because of this characteristics, the frequency of failures is decreasing, but the strength of failures is increasing; therefore, the failure analysis about many complex components or parts was needed. In the former research about Fault Tree Analysis, failure data of similar facilities have been used for forecasting about target system or components, but in case that the system or components for forecasting failure is new or qualitative and quantitative data are given simultaneously, there are many difficulty in using Fault Tree Analysis with this incorrect failure data. Therefore, this paper deal with the Fault Tree Analysis method which be applied with Fuzzy theory in above case. In case that , therefore, if there is no the correct failure data, it is represented a system or components as qualitative variable. subsequently, it converted to the quantitative value using fuzzy theory, and the values used as the value for failure forecast.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1065-1069
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• 2005

The construction failures can be decreased through continuous improvement of construction process based upon the information of construction failures. Herein, the information of construction failures can be utilized as the key factor for identifying and enhancing various ineffective construction processes that can prevent failures. This research proposes a process model for the continuous improvement of construction processes by using construction failure information. Extensive reviews and analyses of literatures related to construction failures are performed to investigate its definition, type, cause, and lessons learned. This research adapts process modeling methodology and case-based reasoning for the development of the proposed CIMCP(continuous improvement model of construction process), and then suggests its framework that contains modules of case retrieval, case index, and case adaptation.

• Structural Engineering and Mechanics
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• 제75권1호
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• pp.123-131
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• 2020

The bond performance of glass fibre reinforced polymer (GFRP) bars and that of steel bars embedded in Alkali Activated Cement (AAC) concrete are analysed and compared using pull-out specimens. The bond failure modes, the average bond strength and the free end bond stress-slip curves are used for comparison. Tepfers' concrete ring model is used to further analyse the splitting failure in ribbed steel bar and GFRP bar specimens. The angle the bond forces make with the bar axis was calculated and used for comparing bond behaviour of ribbed steel bar and GFRP bars in AAC concrete. The results showed that bond failure mode plays a significant role in the comparison of the average bond stress of the specimens at failure. In case of pull-out failure mode, specimens with ribbed steel bars showed a higher bond strength while specimens with GFRP bars showed a higher bond stress in case of splitting failure mode. Comparison of the bond stress-slip curves of ribbed steel bars and GFRP bars depicted that the constant bond stress region at the peak is much smaller in case of GFRP bars than ribbed steel bars indicating a basic bond mechanism difference in GFRP and ribbed steel bars.

• Journal of Chest Surgery
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• 제57권3호
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• pp.319-322
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• 2024

Venovenous extracorporeal membrane oxygenation (VV ECMO) is often used in cases of severe respiratory failure, especially in patients considered for lung transplantation. However, because many lung diseases can ultimately result in right heart failure, the treatment of secondary right heart failure can present a challenge when the patient is already under VV ECMO support. In such cases, an oxygenated-right ventricular assist device (OxyRVAD) can be used. OxyRVAD is designed to maintain anterograde blood flow and prevent right ventricular distension. Moreover, the pulmonary arterial cannula can be inserted percutaneously. We report a case in which percutaneous OxyRVAD was successfully implemented to manage right heart failure in a patient with respiratory failure who was on VV ECMO.

• 한국추진공학회지
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• 제19권5호
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• pp.78-83
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• 2015

복합재 연소관은 적층구조이므로 한 층이 손상되면 손상이 진전되어 전체 연소관의 파손이 발생한다. 금속재 라이너 위에 복합재를 와인딩하면 한 층이 손상되어도 전체 연소관의 파손이 발생되지는 않는다. 본 연구에서는 금속재 연소관에 후프 와인딩한 하이브리드 연소관의 파열압력을 예측하기 위해 유한요소해석과 연소관의 파열시험을 통하여 결과를 비교하였으며, 하이브리드 연소관의 파열압력 예측을 통하여 알루미늄 라이너의 두께를 결정하고 복합재료의 적층두께를 결정함으로써 하이브리드 연소관 설계에 사용할 수 있다.

• 산업공학
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• 제25권4호
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• pp.422-430
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• 2012

In this article, we introduced the estimation method by 'Safety Integrity Level'(SIL) for the criterion of safety assurance and performed a case study on a flame scanner. SIL requires probabilistic evaluation of each set of equipment used to reduce risk in a safety related system. FMEDA(Failure Modes, Effects and Diagnostic Analysis) method is widely used to evaluate the safety levels and provides information on the failure rates and failure mode distributions necessary to calculate a diagnostic coverage factor for a part or a component. Basically, two parameters resulting from FMEDA are used for SIL classification of the device : SFF(Safe Failure Fraction) and PFD(Probability of Failure on Demand). In this case study, it is concluded that the flame scanner is designed to fulfill the condition of SIL 3 in the aspect of SFF and PFD.

• 지질공학
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• 제27권3호
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• pp.267-274
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• 2017

암반은 암석재료 자체의 역학적 성질과 암반내에 분포하는 불연속면의 기하학적 특징에 의해 그 역학적 특성이 좌우된다. 암반사면의 경우에는 불연속면에 의해 특히 파괴면의 위치와 파괴후의 거동 등이 달라진다. 본 논문에서는 불연속면의 규모에 따라 암반사면의 파괴형태가 달라지는 점을 고려하여, 원호파괴와 평면파괴 안정해석을 위한 2개의 3D 해석방법을 개발하고 실제 사면에 적용하여 그 적용성을 검토하였다. 결과, 원호파괴의 경우, 자연건조상태에서는 안정하지만 강우에 의해 표층 함수비가 증가하면 불안정해지는 해석 결과를 얻었다. 평면파괴의 경우도 강우에 의해 불연속면 자체의 마찰각이 감소하는 영향에 의해 건조상태보다 불안정해지는 결과가 나타났다. 이상의 해석 결과로부터 실제 사면에서의 현상을 잘 반영하는 것으로 보아, 개발된 해석방법이 사면안정성 검토 또는 유지관리의 목적으로 적용가능하다고 판단된다.

• The Korean Journal of Pain
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• 제4권2호
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• pp.200-204
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• 1991

Neurolytic splanchnic nerve block is a relatively safe and effective method for the relief of intractable pain caused by upper abdominal cancer. We have experienced a case of severe acute respiratory failure during splanchnic nerve block under control of X-ray fluoroscopy. We think that the most likely cause of the acute respiratory failure was an asthmatic attack due to anxiety and dyspnea from the injury or stimulation of the diaphragm and pleura in this case.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2002년도 춘계학술대회
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• pp.89-95
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• 2002

This paper considers the problem of estimating paramaters of the bivariate exponential distribution with a loaction parameter for a two-component shared parallel system using component data from system-level life test terminated at the time of the prespecified number of system failure. In the system-level life testing, there are three patterns of failure types; 1) both component failed 2) both component censored 3) one is failed and the other is censored. In the third case, we assume that the failure time might be known or unknown. The maximum likelihood estimators are obtained for the case of known/unknown failure time when the other component is censored.