• Journal of Medicine and Life Science
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• 제15권2호
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• pp.108-111
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• 2018

Extra-corporeal membrane oxygenation (ECMO) has the potential to rescue patients in cardiac arrest or respiratory failure. ECMO has two systems such as veno-arterial and veno-venous circulation. In cardiac arrest resulting from acute myocardial infarction, veno-arterial ECMO is mandatory for systemic circulation and oxygenation. A 75-year old female patient underwent primary coronary intervention for acute myocardial infarction. Despite successful revascularization, recurrent ventricular tachycardia and heart failure were progressing. We performed a veno-arterial ECMO through the femoral artery and vein, then the patient seemed to be stable clinically. However, laboratory studies, echocardiography, and vital signs indicated multi-organ failure and decreasing cardiac function. We found out an error that we performed veno-venous ECMO instead of veno-arterial ECMO. We added a femoral artery cannula and exchange the circuit system to veno-arterial ECMO. While the systemic circulation seemed to be recovered, the left ventricular function was decreased persistently. A hypovolemia resulting from pulmonary hemorrhage was occurred, which lead to ECMO failure. The patient died of cardiac arrest and multi-organ failure 23 hours after ECMO. Because the color of arterial and venous circuits represent the position and efficacy of ECMO, if unexpected or abnormal circuit colors are detected, prompt and aggressive evaluation for ECMO function is mandatory.

• Structural Engineering and Mechanics
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• 제63권6호
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• pp.799-808
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• 2017

Failure of a redundant long-span bridge is often described by innumerable failure modes, which make the structural system reliability analysis become a computationally intractable work. In this paper, an innovative procedure is proposed to efficiently identify the dominant failure modes and quantify the structural reliability for a long-span bridge system. The procedure is programmed by ANSYS and MATLAB. Considering the correlation between failure paths, a new branch and bound operation criteria is applied to the traditional stage critical strength branch and bound algorithm. Computational effort can be saved by ignoring the redundant failure paths as early as possible. The reliability of dominant failure mode is computed by FORM, since the limit state function of failure mode can be expressed by the final stage critical strength. PNET method and FORM for system are suggested to be the suitable calculation method for the bridge system reliability. By applying the procedure to a CFST arch bridge, the proposed method is demonstrated suitable to the system reliability analysis for long-span bridge structure.

• 한국해양공학회지
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• 제2권1호
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• pp.95-105
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• 1988

This paper describes the development of a reliability-based optimum design technique for such three dimensional tubular frames as off shore structures. The objective function is formulated for the structural weight. Constraints that probability of failure for the critical sections does not exceed the allowable probability of failure are set up. In the evaluation of the probability of failure, fatigue as well as buckling and plasticity failure are taken into account and the mean-value first-order second-moment method(MVFOSM) is applied for its calculation. In order to reduce the computing time required for the repeated structural analysis in the optimization process, reanalysis method is also applied. Application to two and three dimensional simple frame structures is performed. The influence of material properties, external forces, allowable failure probabilities and interaction between external forces on the optimum design is investigated.

• 품질경영학회지
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• 제23권3호
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• pp.93-101
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• 1995

We present a brief survey concerning the relations between mean residual life and failure rate. Change points of mean residual life and failure rate are known to be different in general and we explore such situations in this paper. A few parametric models which show bathtub-shaped failure rate are examined in details, including the shape of its corresponding mean residual life function. We give some graphical comparisons of trend changes of mean residual life and failure rate for various choices of parameters for each parametric model.

• Communications for Statistical Applications and Methods
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• 제23권6호
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• pp.467-478
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• 2016

The accelerated failure time model or accelerated life model relates the logarithm of the failure time linearly to the covariates. The parameters in the model provides a direct interpretation. In this paper, we review some newly developed practically useful estimation and inference methods for the model in the analysis of right censored data.

• 한국경영과학회지
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• 제25권4호
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• pp.45-54
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• 2000

Estimation Problems of parameters of the failure process and the repair effect in repairable systems are considered. We propose estimation procedures in repairable systems without preventive maintenances. The failure process is modeled by a proportional age reduction model (Brown, Mahoney, Sivazlian [5]) which is able to consider both aging and repair effects. Maximum likelihood method is used to estimate the repair effect and parameters of intensity function simultaneously. simulations are performed to evaluate the accuracy of estimators. A numerical example is also presented.

• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.761-769
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• 2002

Due to the large scale application of software systems, software reliability plays an important role in software developments. In this paper, a software reliability growth model (SRGM) is proposed. The testing time on the right is truncated in this model. The instantaneous failure rate, mean-value function, error detection rate, reliability of the software, estimation of parameters and the simple applications of this model are discussed .

• 한국신뢰성학회지:신뢰성응용연구
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• 제3권1호
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• pp.83-92
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• 2003

We studied the trend change of failure rate function and uncertainty of residual life function in terms of location of their trend change points. It is shown that the trend change of uncertainty of residual life takes place before the failure rate changes its trend. Like DIFR(IDFR) does not necessary implies IDMRL(DIMRL), we find the fact that DIFR(IDFR) does not always imply IDURL(DIURL) under certain conditions, through the exponentiated-weibull distribution.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.640-643
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• 1987

A probabilistic production costing model based on the economic load dispatch has been developed. Objective function is composed of fuel cost which is a function of generation output and the failure cost. Coefficients of the failure cost is determined from the known equivalent generation cost. The model is compared with other existing methodolgies and the excellent results are obtained.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.385.1-385.1
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• 2002

Cordyceps has been used as a tonic for replenishing vital function in Chinese traditional medicines. As an attempt to obtain fundamental data for the kidney function, MeOH Ex. and its hexane. ethyl acetate, butanol and water fractions of cultivated Cordyceps pruinosa on mercuric chloride induced renal failure rats were investigated. Urin volume. blood parameters(urea nitrogen. uric acid. creatinine) and urinary electrolytes content (natrium. potassium. chloride) were determined. MeOH extract and butanol fraction showed diuretic effect. (omitted)