• Tunnel and Underground Space
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• v.21 no.3
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• pp.174-180
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• 2011

An anisotropic version of Mohr-Coulomb failure criterion is proposed in order to provide a strength criterion for transversely isotropic rock. The concept of fabric tensor introduced by Pietruszczak & Mroz (2001) is employed to define the friction angle and cohesion as scalar functions of the fabric tensors. The anisotroy in these two strength parameters are calculated in association with the consideration of the relative rotation between the principal stress coordinate and the principal material triad. The critical plane on which the anisotropic function maximized is found by an optimization technique based on the Lagrange multiplier method. To demonstrate the performance of the anisotropic failure criterion, conventional triaxial tests on the samples having various inclinations of weakness plane are simulated and the resulting triaxial strength and dip angle of failure plane are discussed.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.11-19
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• 2014

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Those accidents can cause disastrous damages if explosiveness gets involved therein such as in weapon systems development. The subject of this paper is on how to incorporate safety requirements in the design of safety-critical systems. As an approach, a useful system structure using the method of design structure matrix (DSM) is studied while reflecting the need on systems safety. Specifically, the effects of system components failure are analyzed and numerically modeled first. Also, the system components are identified and their interfaces are represented using a component DSM. Combining the results of the failure analysis and the component DSM leads to a modified DSM. By rearranging the resultant DSM, a modular structure is derived with safety requirements incorporated. As a case study, application of the approach is also discussed in the development of a military UAV plane.

• Journal of Korean Critical Care Nursing
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• v.7 no.2
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• pp.34-44
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• 2014

Purpose: The purpose of this study was to determine the factors related to airway failure during endotracheal intubation among patients with and without predicted airway difficulty. Methods: Medical records were examined retrospectively. 329 patients who were admitted to the general ward and underwent endotracheal intubation were included. The incidence of airway failure in the two groups was investigated. Results: The group predicted to have airway difficulty consisted of 79 patients (24.0%) and the group without airway difficulty, 250 (76.0%). The number of cases of airway failure was 50 (15.2%). The factors that were associated with airway failure in the group with predicted airway difficulty were the jaw relaxation score, Cormack-Lehane score, and the device of the first endotracheal intubation attempt. The factors that were associated with the airway failure in the group predicted not to have airway difficulty were the induction agent, jaw relaxation score, Cormack-Lehane score, level of training of the personnel with the first endotracheal intubation success, and the device of the first endotracheal intubation attempt. Conclusion: The prediction of airway difficulty during endotracheal intubation was not effective; however, it was meaningful from the perspective of patient safety.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1618-1625
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• 2015

The reliability of catenary system is very important for uninterrupted train operation as it supplies electric power to train without redundant facilities. This paper provides a systematic approach to the reliability analysis of the catenary system based on FMECA procedures defined by global standards such as MIL Std 1692a and IEC 60812. Field failure data collected from the operation and maintenance of high-speed railway catenary system for 9 years are used to derive critical failure modes and to evaluate the criticality of the failure modes. Evaluation of the criticality are carried out by quantitative procedures defined by MIL Std 1692a and by criticality matrix defined by IEC 60812. FMECA results suggests that three critical failure modes should be checked carefully during maintenance work, which include strand break of dropper and voltage equalizing wire, power supply failure of feeder. Maintenance procedure of catenary system in order of importance is suggested too. These results can be applied to maintenance planning and design of catenary system to improve the reliability of electric railway system.

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.548-553
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• 2006

Background : Alcoholic ketoacidosis(AKA) is a metabolic disturbance that is caused by prolonged and excessive alcohol consumption. Though the prognosis is reportedly good, its outcome is unclear in some cases that are combined with multi-organ failure. There are few reports of an analysis of cases admitted to an intensive care unit(ICU) Method: Cases of AKA admitted to the ICU over the last 5 years were retrospectively analyzed. Severe AKA was characterized by multi-organ failure that required treatment in an ICU Results : All patients were males with a history of excessive alcohol consumption. Five of them (50%) mainly complained of gastrointestinal symptoms (nausea, vomiting, diarrhea), showing metabolic acidosis with an increased asmolar and anion gap. Rhabdomyolysis with acute renal failure was the most common combined organ failure. Mechanical ventilation was performed in 80%. Six patients died and 4 patients survived. In the surviving patients, the arterial blood gas analysis(ABGA) was normalized within 12 hours after admission. Conclusion : In severe AKA patients, rhabdomyolysis with acute renal failure was the most common complication. The mortality rate was high and death from shock occurred within 3 days.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.659-665
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• 2016

The limit equilibrium method (LEM) is commonly used for slope design and stability analysis because it is easy to simulate slope and requires short calculating time. However, LEM cannot adequately simulate ploughing failure in a footwall slope with a joint set dipping parallel with slope, e.g. bedding joint set. This study performed parametric study to analyze the influence factors on ploughing failure using UDEC which is a commercial two-dimensional DEM (Distinct Element Method)-based numerical program. The influence of joint structure and properties on stability of a footwall slope against ploughing failure was investigated, and the factor of safety was estimated using the shear strength reduction method. It was found that the stability of footwall slope against ploughing failure strongly relies on dip angle of conjugate joint, and the critical bedding joint spacing and the critical length of slab triggering ploughing failure are also affected by dip angle of conjugate joint. The results obtained from this study can be used for effective slope design and construction including reinforcement.

• Journal of Korean Critical Care Nursing
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• v.6 no.2
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• pp.51-64
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• 2013

Purpose: This study was to analyze adherence to self-care behaviors and identify factors affecting the adherence behaviors among inpatients with heart failure. Methods: A total 94 hospitalized inpatients from three hospitals participated in a survey. Data were collected using structured self-reported questionnaire from November 28, 2011 to March 31, 2013 and analyzed using frequency, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression. Results: The score of adherence to self-care behaviors among inpatients with heart failure was $26.02({\pm}8.84)$. Factors related to the adherence to self-care behaviors were living with spouse (t=-2.47, p=.019), functional state (t=2.18, p=.034), heart failure knowledge (r=-.49, p<.001), social support (r=-.35, p<.001), self-control (r=-.25, p=.016), and self-care confidence (r=-.24, p=.019). The factors affecting adherence to self-care behaviors were heart failure knowledge, self-care confidence, and social support. These factors explained 32% of the variance in adherence to self-care behaviors. Conclusion: The adherence to self-care behaviors with heart failure can be improved if heart failure knowledge, self-care confidence, and social support are improved. Therefore, developing a nursing intervention program for patient with heart failure that is considered these factors leads to improve quality of life and prevent readmission.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.451-461
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• 2016

The objective of this study is to illustrate the methods and procedures for estimating the failure probability of small fill dams subjected to earthquake events and to estimate the seismic failure probability of the Korean disaster risk fill dams where geotechnical information is not available. In this study, first of all, seismic failure probabilities of 7 disaster risk small fill dams, where geotechnical information is available, were evaluated using event tree analysis. Also, the methods and procedures for evaluating probabilities are illustrated. The relationship between dam height and freeboard for 84 disaster risk small dams, for which the safety diagnosis reports are available, was examined. This relationship was associated with the failure computation equation contained in the toolbox of US Army corps of engineers. From this association, the dam height-freeborard critical curve, which represents 'zero' failure probability, was derived. The seismic failure probability of the Korean disaster risk fill dams was estimated using the critical curve and the failure probabilities computed for 7 small dams.

• Tuberculosis and Respiratory Diseases
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• v.53 no.2
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• pp.234-237
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• 2002

A 77-year-old female was admitted 3 hours after intentionally ingesting 5g of aluminum ammonium sulfate ('Alum') powder dissolved in water. Gastric lavage with normal saline, activated charcoal chelation, and supportive therapies were performed. She showed a high anion gap metabolic acidosis, which rapidly progressed to multiple organ failure including ARDS. The patient subsequently progressed to a refractory shock which eventually led to death.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.209-215
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• 1993

A stability analysis program(CSLOP) which can obtain the factor of safety and the critical failure surface at the same time is developed from this study. In order to improve existing slice methods, the general slice method of Gussmann is applied to compute the factor of safety, and the constrained simplex algorithm proposed by Box is applied to systematically locate the critical failure surface in slopes. The proposed method is applied to two examples of circular and noncircular slope stability and the results are compared to previously published solutions. Constrained simplex method is recommended to improve slope stability programs which provide for an automatic search of the critical failure mechanisms.