• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.116-123
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• 1999

A case of the axle gear box which was one of tile power transmission components of high speed train was supported by the bearings installed in axle and the reaction arm connected in bogie frame. Structural analyses of this case were executed for investigation the application of aluminum for weight reduction. The evaluations of the material strength, the thermal strength and deformation, and the stability of natural vibration were carried out according to computer simulation. It was found out that the steel case was safe from the structural failure. For the aluminum case, there was no worry about the vibration resonance and the static failure, but some efforts to reduce tile deformation of the bearing mounting part.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.183-186
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• 2008

필라멘트 와인딩으로 제작된 고체 모터 연소관의 파열특성을 확인하기 위한 해석 및 수압시험을 수행하였다. 본 연소관의 파손 요구조건으로서 운용 중 최대 예상압력(MEOP)의 1.5배 이상의 압력에서 실린더 파손이 일어나야함을 제시하였다. 해석 결과 연소관 내부의 압력이 2088psig 일 때 실린더 파손이 일어나는 것으로 나타났으며 수압시험을 수행하여 2200psig 수준에서 실린더가 파열됨을 검증하였다. 두 결과를 통하여 파열 요구조건을 만족하는 것을 알 수 있다.

• 항공우주기술
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• 제9권1호
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• pp.72-77
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• 2010

필라멘트 와인딩으로 제작된 고체 모터 연소관의 구조강성저하 평가 및 파열특성을 확인하기 위한 수압시험을 수행하였다. 본 연소관의 파손 요구조건으로서 운용 중 최대 예상압력(MEOP)의 1.5배 이상의 압력에서 실린더 파손이 일어나야함을 제시하였다. 해석 결과 연소관의 내부압력이 2088psig 일 때 실린더층의 섬유가 끊어지는 것으로 나타났으며 수압시험을 수행하여 2200psig 수준에서 실린더 부위가 파손됨을 검증하였다. 또한 제작 후 1년 정도 경과 후에도 강성저하가 없음을 알 수 있었다.

• 전기학회논문지P
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• 제59권2호
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• pp.154-157
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• 2010

In this paper, the Time-varying Failure Rates(TFR) of power distribution system components are extracted from the recorded failure data of KEPCO(Korea Electric Power Corporation) and the reliability of power distribution system is evaluated using Mean Failure Rate(MFR) and TFR. The TFR is approximated to bathtub curve using the exponential and Weibull distribution function. In addition, Kaplan-Meier estimation is applied to TFR extraction because of incomplete failure data of KEPCO. Also the reliability of the real power distribution system of Korea is evaluated using the MFR and TFR extracted from real failure data, respectively and the results of each case are compared with each other. As a result, it is proved that the reliability evaluation using the TFR is more realistic than MFR. In addition, it is presented that the application method at power distribution system maintenance and repair using the result of TFR.

• Structural Engineering and Mechanics
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• 제32권1호
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• pp.37-53
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• 2009

In this paper the problem of calculating the probability that the responses of a wind-excited structure exceed specified thresholds within a given time interval is considered. The failure domain of the problem can be expressed as a union of elementary failure domains whose boundaries are of quadratic form. The Domain Decomposition Method (DDM) is employed, after being appropriately extended, to solve this problem. The probability estimate of the overall failure domain is given by the sum of the probabilities of the elementary failure domains multiplied by a reduction factor accounting for the overlapping degree of the different elementary failure domains. The DDM is extended with the help of Line Sampling (LS), from its original presentation where the boundary of the elementary failure domains are of linear form, to the current case involving quadratic elementary failure domains. An example involving an along-wind excited steel building shows the accuracy and efficiency of the proposed methodology as compared with that obtained using standard Monte Carlo simulations (MCS).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.51-55
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• 1997

This study is devote to developing navigation filter for detecting sensor failure in multi-sensor navigation system. In multi-sensor navigation system, Kalman filter is generally used to fuse data of each sensors. Sensor failure is fatal in case that the sensor is used as external measurement of Kalman filter therefore detection and recovery of sensor failure is one the important feature of navigation filter. Generally each sensors have its specific feature in measuring navigational information. Fuzzy theory is proposed to detect external sensor failure and provide valid external measurement to Kalman filter avoiding filter divergence and instability. This idea is applied to Autonomous Underwater Vehicle(AUV) which has two navigation sensor i. e self contained inertial sensor and acoustic external sensor. 2 dimensional simulation result shows acceptable failure detection and recovery

• 대한안전경영과학회지
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• 제16권3호
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• pp.209-218
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• 2014

An accident related with elevators can cause death or serious injury of operators or passengers. This kind of a fatal accident is due to a failure of elevator. The reduction of failures of elevators is important to reduce the occurrence of elevator accident. Thus, this paper presents the results of analysis for the failure of elevators using the failure data of elevator. The results of analysis can be used to make a maintenance process of elevators.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.1154-1160
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• 2009

Cut slope failure is happened in various form by several causes. In this study, we searched causes of cut slope failure shortly, and we made a study of slope failure by excessive under cut. Under cutting slope does to add unstability. Thereby, cut slope failure can be happened on a large scale.

• 대한한방내과학회지
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• 제44권2호
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• pp.146-157
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• 2023

Restless leg syndrome is a nervous system disorder that causes an overpowering urge to move one's legs. Symptoms of restless leg syndrome usually worsen when one tries to fall asleep and can prevent sufficient sleep. Restless leg syndrome is common in patients with chronic kidney failure and can be caused or worsened by chronic kidney failure and hemodialysis. Various medications can treat restless leg syndrome, though the long-term use of medications can cause augmentation and adverse effects. In addition, the use of dopamine agonists is limited in patients with chronic kidney failure. This is because the dose of administration should be controlled for patients with chronic kidney failure, and the treatment effect has not been clearly proven. This study reports the case of a 56-year-old male diagnosed with chronic kidney failure complaining of uncomfortable leg sensations. The patient underwent Korean medicine treatment using Jakyakgamcho-tang. The IRLS, NRS, and AIS scores were evaluation tools during treatment. This study suggested significantly improved symptoms through the individual interventions of Jakyakgamcho-tang in a restless leg syndrome patient with chronic kidney failure.

• Clinics in Shoulder and Elbow
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• 제4권1호
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• pp.35-38
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• 2001

We experienced a rare case of deltoid compartment syndrome by the limb compression during altered consciousness including crush syndrome with myoglobinuric renal failure and report the reviews of those syndromes.