• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.37-44
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• 2002

In order to review the failure rate of PC monitor under normal environmental conditions, we experimented for various levels of each factors, e.g Power on/off, DPM mode, using voltage, Incoming Surge, Torque strength etc. According to the results of experiment and SN ratios we investigated that the causes of the failure for the horizontal output TR of monitor are Mode change, dispersion of Torque and $h_{FE}$ and these are critical effect. For the new reliability test we suggested that strengthened part tests In IQC branch, Torque change controls in the TR specification are necessary.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권8호
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• pp.414-418
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• 2001

Failure modes of Mo-tip FEA were investigated in detail as a preliminary study for the application of Mo-tip FEA to the CRT electron-gun as a cold cathode. It was identified that the destruction of Mo-tip FEA was originated from reflowing of arc-current during the spot-knocking process followed by secondary arc between gate electrode and cathode substrate. In order to prevent Mo-tip FEA from destruction due to arc-current, two kinds of methods were suggested, that is one is to provide the by-pass of the reflow current and the other is to install a current limiter in the path of gate connection line.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.118-121
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• 2002

Polyvinylidene di-fluoride (PVDF) film sensor appeared to be practically useful for the structural health monitoring of composite materials and structures. PVDF film sensors were either attached to or embedded in the graphite/epoxy composite (CFRP) samples to detect the fatigue damage at the bondline of single-lap joints or the tensile failure of unidirectional laminates. PVDF sensors were sensitive enough to detect and determine the crack front in linear location since composites usually produce very energetic acoustic emission (AE). PVDF sensors are extremely cost-effective, as flexible as other plastic films, in low profile as thin as a few tens of microns, and have relatively wide-band response, all of which characteristics are readily utilized for the structural health monitoring of composite structures. Signals due to fatigue damage showed a characteristics of mode II (shear) type failure whereas those from fiber breakage at DEN notches showed that of mode I (tensile) type fracture.

• 한국멀티미디어학회논문지
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• 제20권11호
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• pp.1793-1802
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• 2017

In the recent years, IT and Network Technology has rapidly advanced environment in accordance with the needs of the times, the usage of the smart learning service is increasing. Smart learning is extended from e-learning which is limited concept of space and place. This system can be easily exposed to the various security threats due to characteristic of wireless service system. Therefore, this paper proposes the improvement methods of smart learning system security by use of faults analysis methods such as the FTA(Fault Tree Analysis) and FMECA(Failure Mode Effects and Criticality Analysis) utilizing the consolidated analysis method which maximized advantage and minimized disadvantage of each technique.

• 산업경영시스템학회지
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• 제24권67호
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• pp.69-76
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• 2001

In order to review the failure rate of PC monitor under normal environmental conditions, we experimented for various levels of each factors, e.g. Power on/off, DPM mode, using voltage incoming Surge, Torque strength etc. According to the results of experiment and SN ratios we investigated that the causes of the failure for the horizontal output TR of monitor are Mode change, dispersion of Torque and $h_{FE}$ and these are critical effect. For the new reliability test we suggested that strengthened part tests in IQC branch, Torque change controls in the TR specification are necessary.

• 한국안전학회지
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• 제18권3호
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• pp.39-45
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• 2003

The failure mode of a pipe due to local wall thinning is increasingly more attention in the nuclear power plant industry. To assess the integrity of locally wall thinned pipe, it is necessary to perform many simulations under various conditions. Because the modeling for locally wall thinned elbow is more complicated than that of straight pipe the efficient modeling method for finite element analysis is necessary. In this study, the more simple efficient modeling method of three-dimensional finite element analysis for locally wall thinned elbow has been suggested and verified. And using the method, the failure mode of local wall thinned elbows that have different thinning lengths and circumferential angles is evaluated. From the results, we concluded that the collapse load of elbows has been decreased by the increase of wall thinning shape factors such as thinning lengths and circumferential angles.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1432-1435
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• 2005

We report failure mode observed in polymer EL blue devices, relating with life curve. The modes are analyzed by observing compositional and morphological variation using TEM-EDX, STM, and reverse engineering method as destructive ways, and also investigated mobility changes of hole and electron by measuring transient EL as a nondestructive way corresponding to life curve. We believe that the postulated failure modes in polymer EL devices can present right directions to obtain better performance, especially life time, of polymer devices in material and device structural designing points of view.

• 한국신뢰성학회지:신뢰성응용연구
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• 제10권2호
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• pp.123-135
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• 2010

Failure mode and effects analysis (FMEA) is a widely used technique to assess or to improve reliability of products or processes at early stage of development. Traditionally, the prioritization of failures for corrective actions is performed by evaluating risk priority numbers (RPN). In practice, due to insufficient evaluation criteria specific to related products and processes, RPN is not always evaluated properly. This paper reestablishes an effective methodology for prioritization of failure modes in FMEA procedure. Revised evaluation criteria of RPN are devised and a refined FMEA sheet is introduced. To verify the proposed methodology, it is applied to inspection processes of PCB products.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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• pp.601-606
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• 1998

In recent years, strengthening by steel plate, carbon fiber sheets, and carbon fiber laminate in spotlighted in order to repair and rehabilitation of R/C slabs. In this study, 3 method of rehabilitation are analyzed from the tests. Test parameters are the width of cracks, the method of repair and rehabilitation, the magnitude of pre-load. Deflection, failure load, strains of reinforcing bar, strains of sheet and plates are measured during tests. The failure mode and separption load analyzed from these measured data.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.769-774
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• 2000

The purpose of this study was to investigate the structural performance of reinforcement corrosion reinforced concrete beams strengthened with epoxy mortar system. Main test parameters are existence and the magnitude of the reinforcement corrosion and the reinforcing bar and the tensile reinforcement ratio of the specimens. eight beam specimens were tested to investigate the effectiveness of each test variables on maximum load capacity and failure mode. Test results showed that the ultimate moment of th specimens were higher tan the nominal moment and the flexural stiffness was increased about 2.5 times and the cracking moments occurred over 60% of the failure moment in comparison with same sized control beam. However, note that epoxy mortar may conduct member into brittle failure mode.