• Journal of Aerospace System Engineering
• /
• v.7 no.1
• /
• pp.8-18
• /
• 2013

Recently, the advanced condition monitoring methods such as the model-based method and the artificial intelligent method have been applied to maximize the availability as well as to minimize the maintenance cost of the aircraft gas turbines. Among them the non-linear GPA(Gas Path Analysis) method and the GA(Genetic Algorithms) have lots of advantages to diagnose the engines compared to other advanced condition monitoring methods such as the linear GPA, fuzzy logic and neural networks. Therefore this work applies both the non-linear GPA and the GA to diagnose AE3007 turbofan engine for an aircraft, and in case of having sensor noise and bias it is confirmed that the GA is better than the GPA through the comparison of two methods.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2003.11a
• /
• pp.52-59
• /
• 2003

It is only possible through the image analysis of borehole wall and the core recovered from borehole constructed in rock mass that the real information about geologic characteristics in rock mass is directly obtained in primary research. Monitoring apparatus with multi-functional utility has implemented and applied in-situ condition for finding the geologic condition of target area. But, this apparatus is very expensive to be applied at the risk of loss during monitoring and cause hard work for moving them to the determined position. This paper shows the underground imaging from the borehole information obtained by a borehole camera with the simple utility and low cost enough to investigate the characteristics of borehole wall. Monitoring for this has been done in open-pit mine located at the northeastern part of Fukuoka Prefecture in Japan, and finally the three dimensional imaging of geological discontinuity was discussed relative to the field condition.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1380-1381
• /
• 2008

By applying the digital sub-station, the change of various protect and measuring equipments has been applying. This paper is analyzed that the development of GIS partial discharge condition monitoring equipment is suited to the electricity IT technology and digital sub-station. It's constitution apply to be able to suit the data to high rank for GIS partial discharge condition monitoring equipment that is suited digital sub-station and Watch-dog module that be able to monitor the inner communication of the GIS partial discharge equipment. And then it also be able to apply of GIS partial discharge equipment when digital sub-station is applied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.369-372
• /
• 2004

The characteristics of antimony implants are relatively well-known. Antimony has lower diffusion coefficient, shorter implantation range, and smaller scattering as compared with conventional dopants such as phosphorous and arsenic. It has been commonly used in the doping of buried layer in Bi-CMOS process. In this paper, characteristics and appropriate condition of monitoring in antimony implant beam tuning using $Sb_2O_3$ were investigated to get a reliable process. TW(Thema Wave) and Rs(Sheet Resistance) test were carried out to set up condition of monitoring for stable operation through the periodic inspection of instruction condition. The monitoring was progressed at the point that the slant of Rs varied significantly to investigate the variation of instruction accurately.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.1
• /
• pp.209-214
• /
• 2011

A method to detect rotor mass imbalance, which is one of the typical faults of wind turbine, is presented for effective condition monitoring of wind turbine. Dynamic analysis for a three-bladed horizontal-axis wind turbine was carried out with adding mass to a blade for inflicting the rotor mass imbalance. It has been found that the added mass induce a resulting centrifugal force to nacelle and this leads to a transverse (relative to the rotor axis) oscillation of the nacelle. It has been also found that the amplitude of the oscillation is almost linearly increased as the added mass is increased.

• Nuclear Engineering and Technology
• /
• v.49 no.3
• /
• pp.632-637
• /
• 2017

Even though the potential for an accident in nuclear power plants is very low, multiple emergency plans are necessary because the impact of such an accident to the public is enormous. One of these emergency plans involves a robotic system for investigating accidents under conditions of high radiation and contaminated air. To develop a robot suitable for operation in a nuclear power plant, we focused on eliminating the three major obstacles that challenge robots in such conditions: the disconnection of radio communication, falling on uneven floors, and loss of localization. To solve the radio problem, a Wi-Fi extender was used in radio shadow areas. To reinforce the walking, we developed two- and four-leg convertible walking, a floor adaptive foot, a roly-poly defensive falling design, and automatic standing recovery after falling methods were developed. To allow the robot to determine its location in the containment building, a bar code landmark reading method was chosen. When a severe accident occurs, this robot will be useful for accident condition monitoring. We also anticipate the robot can serve as a workman aid in a high radiation area during normal operations.

• Journal of Drive and Control
• /
• v.18 no.1
• /
• pp.24-30
• /
• 2021

There is an increasing interest in condition-based maintenance for the prevention of economic loss due to failure. Moreover, immense research is being carried out in related technologies in the field of construction machinery. In particular, data-based failure diagnosis methods that employ AI (machine & deep learning) algorithms are in the spotlight. In this study, we have focused on the failure diagnosis and mode classification of reduction gear of excavator's travel device by using the AI algorithm. In addition, a remote monitoring system has been developed that can monitor the status of the reduction gear by using the developed diagnosis algorithm. The failure diagnosis algorithm was performed in the process of data acquisition of normal and abnormal under various operating conditions, data processing and analysis by the wavelet transformation, and learning. The developed algorithm was verified based on three-evaluation conditions. Finally, we have built a system that can check the status of the reduction gear of travel devices on the web using the Edge platform, which is embedded with the failure diagnosis algorithm and cloud.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.687-688
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.181-182
• /
• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.75-76
• /
• 2013