• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2015-2020
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• 2011

Key set the current non-urban rail power failure of equipment to operate the railway will generate a lot of problems. I know in advance the ideal of power equipment to prevent the failure to derive an efficient replacement cycle for the power equipment monitoring and diagnosis of the condition can become necessary to develop a system. In order to determine the status of the power plant during operation and behavior of the partial discharge current state data, regular monitoring and inspection requirements also stamp the basic current, voltage, temperature and humidity should be identified.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1386-1390
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• 2007

This paper presents the equipment condition monitoring technology for the process or the equipment using statistical techniques. The equipment condition monitoring system consists of an empirical model to estimate the expected sensor values of process variables and a diagnose model to detect the abnormal condition and to identify the root source of the problem. The empirical model is constructed by the analysis of historic data. The diagnose model uses the sequential probability ratio test (SPRT) technique. The monitoring system was tested with real operating data acquired from the Reactor Coolant Pump Seal in the Nuclear Power Plant. It can detect the system degradation or failure at the early stage since it is able to catch the subtle deviation of process variables from normal condition.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.6
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• pp.261-266
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• 2021

Nuclear power plants in Korea were designed and evaluated based on the NRC's Regulatory Guide 1.60, a design response spectrum for nuclear power plants. However, it can be seen that the seismic motion characteristics are different when analyzing the Gyeongju earthquake and the Pohang earthquake that has recently occurred in Korea. Compared to the design response spectrum, seismic motion characteristics in Korea have a larger spectral acceleration in the high-frequency region. Therefore, in the case of equipment with a high natural frequency installed in a nuclear power plant, seismic performance may be reduced by reflecting the characteristics of domestic seismic motions. The failure modes of the equipment are typically structural failure and functional failure, with an anchorage failure being a representative type of structural failure. In this study, comparative analyses were performed to decide whether to consider the inelastic behavior of the anchorage or not. As a result, it was confirmed that the seismic performance of the anchorages could be increased by considering the inelastic behavior of an anchorage.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.79-87
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• 2024

In a previous study, the suitability for use of inspection equipment was evaluated at temperatures outside the quality assurance range. The quality assurance operating temperature of the safeguards equipment is 0~+40℃, and previous studies have confirmed the performance of the safeguards equipment for temperatures ranging from -40~+70℃. The scintillator-based verification equipment showed a shift in the centroid channel and a change in the count rate in all temperature ranges, and the semiconductor-based safeguards equipment generated Leakage Current and equipment failure. In this study, a retrofit was performed applying a vacuum housing to the safeguards equipment (Inspector-2000-based inspection equipment), and performance evaluation was performed at a low temperature and snowy site, and it was confirmed that the same performance was observed as the measurement results at room temperature.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.227-232
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• 2004

The failure of geogrids can be defined as an excessive creep strain which causes the collapse of slopes and embankments. In this study, the accelerated creep tests were applied to two different types of polyester geogrids, at 75, 80, 85$^{\circ}C$ by applying 50% load of ultimate tensile strengths using a newly designed test equipment which is allowed the creep testing at higher temperatures. And then the creep curves were shifted and superposed in the time axis by applying time-temperature supposition principles. In predicting the lifetimes of geogrids, the underlying distribution for failure times were determined based on identification of the failure mechanism. The results indicate that the conventional procedures with the newly designed test equipment are shown to be effective in prediction of the lifetimes of geogrids with shorter test times. In addition, the predicted lifetimes of geogrids having different structures at various creep strains give guidelines for users to select the proper geogrids in the fields.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.69
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• pp.1-12
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• 2001

In this paper, the consumable concurred spare parts requirement determination problem of newly procured equipment systems is considered. The problem is formulated as the operational availability maximization problem with any given fund limitation. the that the failure of a part follows a Poisson process and part failure rate is constant in spite of the decrease of number of equipments during operational period, an analytical method is developed to obtain spare part requirements using the generalized Lagrange multipliers method, The numerical examples show that analytic solution is mostly equal to the realistic solution obtained from simulation regardless of assumptions about part failure rate. It is expected that the analytical method developed in the paper can be effectively used to make a budget for provisioning the concurrent spare parts of newly procured equipment system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.223-230
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• 2004

It is growing the application of the removal ground anchor with tension force for earth retaining constructions in the downtown. Nowadays, we can find the compression dispersion anchor on many site. But, it is occur some probelems in behabior of anchors because of impossible to tense p.c strand uniformly with existing equipment due to different length of p.c strand. So we tried to tense each p.c strand uniformly with auto back equipment in-situ test. This study compared and analyzed apply to elastic theory in-situ test results of an existing equipment with those of auto back equipment. As a result of the test, It has been proved that differences of tension force in the existing equipment increases with increasing the number of p.c strand. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground. So it has been proved that auto back equipment is necessary.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.121-126
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• 2017

EES System support to maximize equipment efficiency by providing real-time information of main equipment which has a significant effect on product quality and productivity, and to prevent equipment failure by detecting equipment abnormality in advance. Smart Equipment Engineering System(S-EES) integrates the activities performed at equipment that are the core of production activities and manages them by system so as to maximize the efficiency of equipment and raise the quality level of products to one level. In other words, when the product is put into the equipment, the recipe is downloaded through the RMS, the recipe is set to the optimal condition through R2R(process control), and the system detects and controls the abnormality of the equipment during operation through the FDC function in real time it means. In this way, we are working with the suitable recipe that matches the lot of product, detecting the abnormality of the equipment during operation, preventing the product from being defective, and establishing a system to maximize the efficiency through real-time equipment management. In this study, we review the present status and problems of equipment management in actual production lines, collect the requirements of the manufacturing line for the PCB line, design and develop the system, The measurement model was studied.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.647-652
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• 2008

Railway signal system has been more complex, larger and required high reliability. So, maintenance by experience must be changed to optimize maintenance program or introduced systematic method for estabilish new maintenance program. In this paper, we introduced the maintenance period decision method which are Age based method and Block replacement method based on the failure distribution for the equipment. So, we allocated optimum maintenacne period for the railway signal equipment using block replacement method.

• Journal of the Korean Data and Information Science Society
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• v.21 no.1
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• pp.109-119
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• 2010

FRACAS (Failure Reporting, Analysis and Corrective Action System) is intended to provide management visibility and control for reliability and maintainability improvement of hardware and associated software by timely and disciplined utilization of failure and maintenance data to generate and implement effective corrective actions to prevent failure recurrence and to simplify or reduce the maintenance tasks. This process applies to acquisition for the design, development, fabrication, test, and operation of military systems, equipment, and associated computer programs. This paper shows the FRACAS development process and developed FRACAS system for a defense equipment.