• Title/Summary/Keyword: failure case

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A Study on the Failure Behavior of the Reinforced Earth Wall Structures according to the Deformed Types of the Face (전면부 변형형태에 따른 보강토 벽체 구조물의 파괴거동에 관한 연구)

  • 김준석;이상덕
    • Journal of the Korean Geotechnical Society
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    • v.15 no.4
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    • pp.167-173
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    • 1999
  • In this paper the failure behavior of the reinforced earth retaining wall structures according to the deformed types of the face was studied by model test using carbon rods. In model test the behavior of the face for the model of the reinforced earth wall was divided into three cases : the displacement of the top part(case 1), the lateral displacement(case 2) and the displacement of the lower part (case 3). The photographic method was applied to examine the failure line of the deformed wall with the naked eye. The failure line shows a parabolic shape for case 1, a large circular arc for case 2 and a logarithmic spiral for case 3 in the experimental results. The design failure line for the coherent gravity structure hypothesis was most similar to the failure line for the case of the lower part displacement.

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Development of uncertainly failure information for FFTA (FFTA(Fuzzy Fault Tree Analysis)에 의한 불확실한 고장정보 연구)

  • 정영득;박주식;김건호;강경식
    • Journal of the Korea Safety Management & Science
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    • v.3 no.2
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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.

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A CONSTRUCTION PROCESS IMPROVEMENT MODEL USING CONSTRUCTION FAILURE INFORMATION

  • Yongseok Jeon;Chansik Park
    • International conference on construction engineering and project management
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    • 2005.10a
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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.

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Bond properties of steel and sand-coated GFRP bars in Alkali activated cement concrete

  • Tekle, Biruk Hailu;Cui, Yifei;Khennane, Amar
    • Structural Engineering and Mechanics
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    • v.75 no.1
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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.

Percutaneous OxyRVAD in a Patient with Severe Respiratory Failure and Right Heart Failure: A Case Report

  • Ga Young Yoo;June Lee;Seok Beom Hong;Do Yeon Kim
    • Journal of Chest Surgery
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    • v.57 no.3
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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.

Burst Prediction of Hoop Winding Composite Case with Metal Liner (금속라이너를 가진 후프 와인딩 복합재 연소관의 파열예측)

  • Han, Houkseop;Kim, Hyung-kun;Lee, Young-won
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.5
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    • pp.78-83
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    • 2015
  • In the composite case, the first ply failure is considered total failure of the case. When the case is constructed by filament winding over a metal liner, the first ply failure does not necessarily mean total failure of the case. In this study, we compared the results through finite element analysis and burst test to predict the burst pressure of the hybrid case (filament-wound composite case with metal liner). Through it predicts the burst pressure of the hybrid case, we can determine the thickness of the metal liner and composite.

Recovery of complete left bundle branch block in dilated cardiomyopathy after optimal heart failure treatment: a case report

  • Geum Ko;Jae-Geun Lee
    • Journal of Medicine and Life Science
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    • v.21 no.3
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    • pp.112-116
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    • 2024
  • Complete left bundle branch block (CLBBB) is a significant cardiac conduction abnormality often associated with dilated cardiomyopathy (DCM). This case report highlights the improvement in CLBBB and symptom relief through reverse cardiac remodeling in a patient diagnosed with DCM following an optimized heart failure treatment regimen consisting of an angiotensin-converting enzyme inhibitor, beta-blocker, and mineralocorticoid receptor antagonist. This case highlights the potential of electrical remodeling and conduction system improvement in patients with DCM receiving optimized medical therapy.

A Study on FMEDA Process for SIL Certification : A Case Study of a Flame Scanner (SIL 인증을 위한 FMEDA 프로세스 연구 : 화염검출기 사례를 중심으로)

  • Kim, Sung Kyu;Kim, Yong Soo
    • IE interfaces
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    • v.25 no.4
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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.

Review of Applicability of Analysis Method based on Case Study on Rainfall-Induced Rock Slope Failure (강우에 의한 암반사면 파괴 해석 사례 연구를 통한 해석방법 적용성 검토)

  • Jung, Jahe;Kim, Wooseok
    • The Journal of Engineering Geology
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    • v.27 no.3
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    • pp.267-274
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    • 2017
  • Behavior of rock mass depend on the mechanical properties of intact rock and geometrical property of discontinuity distributed in rock mass. In case of rock slope, particularly, location of slope failure surface and behavior after failure are changed due to discontinuities. In this study, two 3D slope stability analysis methods were developed for two different failure types which are circular failure and planar failure, considering that failure type of rock slope is dependent on scale of discontinuity which was then applied to real rock slope to review the applicability. In case of circular failure, stable condition was maintained in natural dry condition, which however became unstable when the moisture content of the surface was increased by rainfall. In case of planar failure, rock slope become more unstable comparing to dry condition which is attributable to decrease in friction angle of discontinuity surface due to rainfall. Viewing analysis result above, analysis method proved to have well incorporated the phenomenon occurred on real slope from the analysis result, demonstrating its applicability to reviewing the slope stability as well as to maintaining the slope.

Acute Respiratory Failure during Splanchnic Nerve Block in COPD Patient (만성폐색성 폐질환 환자에서의 내장신경차단중 발생한 급성호흡부전)

  • Chang, Won-Young;Choe, Kun-Chun
    • The Korean Journal of Pain
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    • v.4 no.2
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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.

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