• The Journal of Internal Korean Medicine
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• v.29 no.4
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• pp.1115-1122
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• 2008

Chronic renal failure (CRF) is defined as a permanent reduction in glomerular filtration rate (GFR) sufficient to produce detectable alterations in well-being and organ function. This usually occurs at GFR below 25 ml/min. In this report, is a 75-year-old woman who had back pain and diarrhea as chief complaints. She was diagnosed with CRF on March. 2008. is a 62-year-old man who had whole body weakness, anorexia and dyspepsia as chief complaints. He was diagnosed with CRF on 2008. We used herbal enteroclysis solution. which consists of Radix et Rhizoma Rhei. Concha Ostreae and Radix Glycyrrhizae or Radix Salviae Miltiorrhizae. Herbal enteroclysis was done for 15 min once a day. Enteroclysis solution was controlled at 37-39 $^{\circ}C$ and inserted 15-20cm depth for intubation. We found the patient's BUN, creatinine and GFR were improved through enteroclysis. In both and , the patient's BUN and creatinine decreased, and GFR increased favorably. This result suggests that herbal enteroclysis used for CRF is effective in clinical therapy.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1357-1365
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• 2011

Reliability analysis-based maintenance system has the merit than elapsed time-based preventive maintenance system. First, it is possible to active handling of rolling stocks failures. In the past, Failure handling activities began when after increase failures rapidly. But if we can continuous manage of reliability than changing of failure tendency can know more quickly. Second, It is possible to using maintenance resources effectively. We can look forward to cost reduction to distributing of much less failures parts's maintenance resources. KORAIL builds reliability system called KTX-RCM for operating high-speed rolling stocks. But existing rolling stocks have not reliability system from the past. Fortunately, KORAIL started ERP system called KOVIS at 2007. KOVIS includes maintenance data for reliability analysis. So in this study analysis failure data for getting reliability number about existing passenger car. And we desire to maintenance connection plan.

• Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.187-193
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• 2014

One of the hottest challenges in automotive industry is related to weight reduction in sheet metal forming processes, in order to produce a high quality metal part with minimal material cost. Stamping is the most widely used sheet metal forming process; but its implementation comes with several fabrication flaws such as springback and failure. A global and simple approach to circumvent these unwanted process drawbacks consists in optimizing the initial blank shape with innovative methods. The aim of this paper is to introduce an efficient methodology to deal with complex, computationally expensive multicriteria optimization problems. Our approach is based on the combination of methods to capture the Pareto Front, approximate criteria (to save computational costs) and global optimizers. To illustrate the efficiency, we consider the stamping of an industrial workpiece as test-case. Our approach is applied to the springback and failure criteria. To optimize these two criteria, a global optimization algorithm was chosen. It is the Simulated Annealing algorithm hybridized with the Simultaneous Perturbation Stochastic Approximation in order to gain in time and in precision. The multicriteria problems amounts to the capture of the Pareto Front associated to the two criteria. Normal Boundary Intersection and Normalized Normal Constraint Method are considered for generating a set of Pareto-optimal solutions with the characteristic of uniform distribution of front points. The computational results are compared to those obtained with the well-known Non-dominated Sorting Genetic Algorithm II. The results show that our proposed approach is efficient to deal with the multicriteria shape optimization of highly non-linear mechanical systems.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.89-96
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• 2020

Solar lamp systems may not operate normally in the event of some system or controller failure due to internal or external factors, in which case secondary problems occur, which may cost the system recovery. Thus, when these errors occur, a technology is needed to recover to the state it was in before the failure occurred and to enable re-execution. This paper designs and implements a system that can recover the state of the system to the state prior to the time of the error by using the Watchdog Timer within the controller if a software error has occurred inside the system, and it also proposes a technology to reset and re-execution the system through a separate reset circuit in the event of hardware failure. The proposed system provides stable operation, maintenance cost reduction and reliability of the solar lamp system by enabling the system to operate semi-permanently without external support by utilizing the automatic recovery and automatic reset function for errors that occur in the operation of the solar lamp system. In addition, it can be applied to maintain the system's constancy by utilizing the self-operation, diagnosis and recovery functions required in various high reliability applications.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.368-376
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• 2005

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under thermal and mechanical loadings. In this study, for EPDM(ethylene-propylene diene monomer) rubber conventionally used as a radiator hose material the aging behaviors of the skin part due to thermo-oxidative and electro-chemical stresses were nondestructively evaluated. Through the thermo-oxidative aging test, it was shown that the surface hardness IRHD(International Rubber Hardness Degrees) of the rubber increased with a considerable reduction of failure strain. On account of the penetration of coolant liquid into the skin part the weight of rubber specimens degraded by electro-chemical degradation(ECD) test increased, whereas their. failure strain and IRHD hardness decreased largely. The penetration of coolant liquid seemed to induce some changes in inner structure and micro hardness distribution of the rubbers. Consequently, EPDM rubbers degraded by thermo-oxidative aging and ECD could be characterized nondestructively by micro-hardness and chemical structure analysis methods.

• Structural Engineering and Mechanics
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• v.62 no.5
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• pp.567-576
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• 2017

Structural failures are undesirable events that devastate the construction industry resulting in loss of life, injury, huge property loss, and also affect the economy of the region. Roof truss failures occur mainly due to excessive loading, improper fabrication, deterioration, inadequate repair, etc. Although very rare, a roof truss may even fail due to inappropriate location of supports. One such case was reported from the recent failure of a steel roof truss used in an indoor stadium at Kargil in India. Kargil region, being mountainous in nature, receives heavy snowfall and hence the steel roof trusses are designed for heavy snow loads. Due to inappropriate support location, the indoor stadium's steel roof truss had failed under heavy snow load for which it was designed and became an interesting structural engineering problem. The failure observed was primarily in terms of yielding of the bottom chord under the supports, leading to partial collapse of the roof truss. This paper summarizes the results of laboratory tests and analytical studies that focused on the validation of the proposed remedial measure for rehabilitating this distressed steel roof truss. The study presents the evaluation of (i) significant reduction in strength and stiffness of the distressed truss resulting in its failure, (ii) desired recovery in both strength and stiffness of the rectified truss contributed by the proposed remedial measure. Three types of models i.e., ideal truss model, as build truss model and rectified truss model were fabricated and tested under monotonic loading. The structural configuration and support condition varied in all the three models to represent the ideal truss, distressed truss and the rectified truss. To verify the accuracy of the experimental results, an analytical study was carried out and the results of this analytical study are compared with the experimental ones.

• Journal of IKEEE
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• v.24 no.2
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• pp.385-391
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• 2020

Overcurrent and abnormal voltages in the distribution system can cause not only burden of power plant but also damage to customers. As a result, researches related to the distribution automation have been widely conducted by utilizing a real time digital simulation to improve the reliability of power supply through rapid failure handing, reduction of power failure intervals and failure recovery. However, the distribution automation systems using the real time digital simulator are expensive and limited to verify actual hardwares. Therefore, in this paper, an external hardware devices was developed based on the distribution system analysis results of the digital simulator. And real-time simulation and functional verification are implemented by the real feeder remote terminal units used in distribution automation. The effectiveness of the proposed system is verified through several experiments.

• Journal of the Korean Society for Nondestructive Testing
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• v.7 no.2
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• pp.42-47
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• 1988

The off-axis tensile strength of the unidirectional carbon fiber reinforced plastic and the residual strength of impact damaged CFRP were measured and compared with the stress wave factor (SWF) of the specimens. The SWF values were measured to be decreased with the strength reduction in both cases and found to be useful for the nondestructive strength evaluation of unidirectional CFRP. The failure behaviour of the unidirectional CFRP during off-axis tensile testing was also monitored by acoustic emission(AE) method. The AE energy release showed the characteristic feature depending on the off-axis angle and this result was analyzed to be caused by the difference of the expected failure mode depending on the off-axis angle. The failure mode of CFRP was found to be analyzed by investigation of the peak amplitude distribution of AE.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.1-5
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• 2016

A bicycle is one of the most popular sporting goods in view of a sport activity and a human health. Metallic materials such as steel, aluminum, etc. were mainly used to the bicycle fork in the past. Nowadays, the carbon fiber reinforced composite materials are widely used to the manufacturing of a bicycle fork to reduce the weight and to increase the efficiency. Safety is a most important design parameter of a bicycle fork even if the weight and cost reduction are important. Bicycle failure may happen at the critical spot of a bicycle fork and cause the accident. In this paper, the composite bicycle fork will be analyzed to secure the safety and detect a critical spot by using the finite element method with Tsai-Wu failure criterion. The stress data were obtained for the laminated composites with various number of plies and fiber orientation under the bending load. Thus, design concept of a bicycle fork was proposed to secure the safety of a bicycle. The finite element analysis results show that the connection area between a steer tube and a fork blade is critical spot, and 75 or more layers of 0 degree are needed to secure the safety of a bicycle fork.

• Journal of Yeungnam Medical Science
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• v.31 no.1
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• pp.38-42
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• 2014

Cardiovascular beriberi is caused by thiamine deficiency and usually presents as high cardiac output failure associated with predominantly right-sided heart failure and rapid recovery after treatment with thiamine. Because of its rarity in developed countries, the diagnosis can often be delayed and missed. We recently experienced a case of cardiovascular beriberi with pulmonary hypertension which successfully treated with thiamine infusion. A 50-year-old man with chronic heavy alcoholics was refered to our department for dyspnea with mental change. Echocardiography showed marked right ventricular (RV) dilatation and flattening of the interventricular septum with a D-shaped deformation of the left ventricle. Moderate tricuspid valve regurgitation was found and estimated RV systolic pressure was 52 mm Hg. Because of his confused mentality and history of chronic alcohol intake, neurological disorder due to thiamine deficiency was suspected and intravenous thiamine was administered and he continuously received a daily dose of 100 mg of thiamine. Follow up echocardiography showed marked reduction of RV dilatation and improvement of a D-shaped deformation of the left ventricle. He finally diagnosed as cardiovascular beriberi on the basis of dramatic response to intravenous thiamine. Thiamine deficiency can cause reversible pulmonary hypertension, and can still be encountered in the clinical setting. Thus high index of suspicion is critically needed for diagnosis.