• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.17-21
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• 2012

The periodic technical vehicle inspection is to prevent the accident through the finding and fixing the defects of the vehicle. The periodic technical vehicle inspection in Korea was studied for assessing the adequacy of the inspection frequency. The inspection frequencies of many countries including EU, USA and Japan were compared. The average mileages by the vehicle usage and type were represented. The warranty period and recommended replacement period of parts of the domestic auto makers was studied. Currently, the inspection frequency for the periodic technical vehicle inspection in Korea is appropriate. The pass-fail rate and the cost-benefit analysis for the periodic technical inspection in Korea will be needed in the decision making process for the inspection frequency.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.3
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• pp.95-101
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• 2000

In this paper, an improved method for magnetic inspection to detect surface of a conductor is presented. The presented method is based on the technique of ECP(Electric Current Perturbation), which is to measure the variation of current flow due to defects with a magnetic sensor. The inspection performance is improved by using high frequency current behaviors in order to concentrate the current near the defect and employing the resonant frequency of a search coil as an operating frequency. By analytical results and experiments of the test specimens, the feasibility of the inspection method is shown.

• Structural Engineering and Mechanics
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• v.64 no.3
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• pp.347-352
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• 2017

The poor maintenance practice increases the possibility of system failure. Subsequently, the consequences of failure fall on the aspects of output, safety and healthy, environmental integrity, system quality, and customer satisfaction. Conditionbased maintenance is seen as a potential strategy to improve performance. Whereby, the key success factor of this maintenance strategy is identified as the system inspection. This study aims to investigate the association between system breakdown rate and frequency of inspection. A mixed method approach is implemented by distributing questionnaire and interviewing for data collection. Subsequently, descriptive analysis, correlation analysis and regression are adopted to analyse the collected data from 100 respondents and the results are validated with interview data of 10 interviewees. The research result establishes significant relationship between the system breakdown rate and the frequency of inspection. Additionally, the result of regression analysis confirms that the frequency of inspection is the significant predictor of system breakdown rate. Planning of accurate inspection frequency is crucial to secure the system performance. Hence, the research signifies the importance to carry out regular inspection towards the building systems and components. As a recommendation, the maintenance personnel should assess the risk criticality of the building systems. Then, continuously monitor the condition of critical building systems; regularly inspect the condition of non-critical building systems and randomly inspect all of them.

• Journal of the Korean Society of Safety
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• v.22 no.6
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• pp.35-40
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• 2007

As a way of improving the safety of the chemical facilities, the risk based-inspection(RBI) was executed for the facilities of the applied petrochemical plant using KS-RBI Ver. 3.0 program developed based on the API-581 based resource document(BRD). From an evaluation result of KS-RBI program, we could find the evaluation of the process safety management(PSM) for the applied plant, risk of the applied process, risk of static facilities and pipes, and the demage mechanism of the facilities. Also, we could suggest a proper inspection plan(frequency and method of inspection) using the calculated risk and the status of the facilities. Therefore, the applied plant could be achieved a reduced inspection cost by an extension of inspection frequency, improved productivity, improved reliability of the facilities, and a computerized history management.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.9-18
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• 2000

This study includes noise automatic inspection system for washing machine auto-transmission one of modern home necessary. We effort to find and certificate sound noise source by sound power and sound intensity, and apply to frequency analysis in vibration related sound noise. still more we have been studying to data acquisition and programming for MS VisualBasic version 5.0. System component is below. 1) Pentium PC or data acquisition. 2) DSO for noise acquisition. 3)S/W for comparison and decision. 4) I/F Board for data communication. Wave form data through the DSO are converting to ASCII code data. The ASCII code through binary converting S/W. Finally we will making noise monitoring system and automatic inspection system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.41-45
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• 2006

The fabrication process of fiber placement system of carbon fiber reinforced plastic (CFRP) requires real time process control and reliable inspection to ensure quality by preventing defects such as delamination and void. Therefore, novel non-contact inspection technique is required during the non-destructive evaluation in a fiber placement system. For the inspection of delamination in CFRP, various methods to receive laser-generated ultrasound were applied by using piezoelectric transducer, air-coupled transducer, wavelet transform and scanning laser ultrasonic technique. Laser-generated ultrasound was received with a conventional piezoelectric sensor in contacting manner. Then signal characteristics due to defects were analyzed to find a factor for detecting defects. Air-coupled transducer was used for reception of laser-generated guided wave using linear slit array in order to generate high frequency guided wave. And line scan technique was used to confirm the capability of on-line application. The high frequency component of laser-generated guided wave received with piezoelectric sensor disappeared after propagating through delamination region. Nevertheless, it was failed to receive high frequency guided wave in using air-coupled transducer. The first peak of the frequency spectrum under 100kHz in the delamination region is higher than in the sound region. By using this feature, the line scanned frequency data were acquired in fully non-contact generation and reception of ultrasound. This method was proved as useful technique for detecting delamination in CFRP.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.603-612
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• 2009

The bogie hunting sensor detects accelerations of a bogie. It transmits those accelerations using frequency modulated signal to the TCMS(Train Control and Management System) electronics for functional processing. TCMS decide undesirable bogie hunting and high speed instability with frequency modulated signal. The bogie hunting sensor is essential component for safety driving of high speed train. The bogie hunting sensor's quality inspection before sensor is installed on bogie is very important. Therefore it is required equipment for exact inspection of train bogie hunting sensor. This study is about development of Bogie Hunting sensor's inspection equipment that we can improve Bogie Hunting sensor's quality. Accordingly, I suppose that this thesis will be utilized to improve the bogie hunting sensor's quality thru exact inspection.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.13-19
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• 2006

As a way of improving the safety of the facilities, the risk based-inspection (RBI) was executed for the chemical facilities by using K-RBI program, which has been developed based on the API-581 based resource document (BRD). As the result of the evaluation, we found the level of the process safety management (PSM) for the applied plant, quantitative risk of the applied process, risk of static facilities and pipes, and the damage mechanism of the facilities. Thus, we could suggest a proper inspection frequency using the calculated risk of the process and the status of the facilities. The applied plant achieved a reduced inspection cost by an extension of the inspection frequency, improved productivity, improved reliability of the facilities, and a computerized history management.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1345-1348
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• 2003

The Ferrule for the Optical Communication Connector is the product to set the optical ares of an optical fiber very precisely. Therefore, it is required high expectations such as high dimensional precision and new including flaws. Up to new the optical instrument has been used for the defeat and shape inspection of the ferrule, but in the paper we examined the detectable defeat and expectation by using Resonant Ultrasound Spectroscopy(RUS). The RUS is the measurement which is to excite specimen and to inspect the difference at natural frequency pattern between acceptable specimen and specimen which has some defeats. We analyzed the difference of natural frequency pattern in the experiment using Spectrum Analyzer. And we compared the results in the experiment with those in the simulation from the explicit finite elements code, Nastran.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1177-1183
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• 2013

In this paper, the analysis of inspection period bases on reliability is suggested in the field of traction power system. Even though there are several maintenance models, the most commonly used maintenance assessment has been focused on time based maintenance in real traction power systems. The maintenance intervals are selected on the basis of long-time experience. It ensures high availability and exact planning of staff. Reliability centered maintenance, which evaluates criticality and severity of each failure mode, achieves the operation, maintenance, and cost-effective improvement that will manage the risks of equipment. This paper deals with electrification in railway inspection frequency and applied reliability based inspection frequency instead of constant intervals. The distribution function of failure rate in traction power system belongs to Weibull function. Also, the fault data and the number of installed equipments for electrifications are collected. The failure history is investigated and classified in detail. Though these complicated procedures, it contribute to extend equipment lifetime and to reduce maintenance costs.