• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.2
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• pp.130-137
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• 2016

Non-destructive testing methods for composite materials (e.g., carbon fiber-reinforced and glass fiber-reinforced plastic) have been widely used to detect damage in the overall industry. This study detects defects using optical infrared thermography. The transient heat transport in a solid body is characterized by two dynamic quantities, namely, thermal diffusivity and thermal effusivity. The first quantity describes the speed with thermal energy diffuses through a material, whereas the second one represents a type of thermal inertia. The defect detection rate is increased by utilizing a lock-in method and performing a comparison of the defect detection rates. The comparison is conducted by dividing the irradiation method into reflection and transmission methods and the irradiation time into 50 mHz and 100 mHz. The experimental results show that detecting defects at 50 mHz is easy using the transmission method. This result implies that low-frequency thermal waves penetrate a material deeper than the high-frequency waves.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.18 no.1
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• pp.1-10
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• 2022

Currently, there is no technical standard and regulation for seismic analysis of non-nuclear safety piping. Accordingly, ASME Sec.III ND, a standards applied to safety class 3 piping, is applied. However, the technical standard applied for other than seismic analysis is ASME B31, which leads to controversy. In this study, the feasibility of applying ASME B31E was confirmed by reviewing rulescomparing technical standards, and evaluating piping allowable stress margins. The evaluation revealed that applying ASME B31.1 as a technical standard is too conservative compared to ASME Sec.III ND. On the other hand, ASME B31E (issued at the request of the industry) clearly presents the technical standards for seismic analysis of ASME B31 piping, and shows a similar level of conservatism compared to ASME Sec.III ND. It is expected to reduce the controversy over technical standards for seismic analysis of non-nuclear safety piping by applying ASME B31E.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.2
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• pp.131-136
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• 2024

This paper deal with a method for calculating the continuity of Korea Augmentation Satellite System (KASS), which was completed in Korea in December 2023, and a plan to respond in the event that a continuity hazard situation occurs during operation. For this purpose, the International Civil Aviation Organization (ICAO) Satellite Based Augmentation System (SBAS) continuity standards, Wide Area Augmentation System (WAAS), and European Geostationary Navigation Overlay Service (EGNOS) continuity cases are examined in this paper. According to the measures recommended by the ICAO, when the number of continuity risks exceeds a certain level and the level drops drastically, various mitigation operations by country are implemented. Through this, if KASS does not meet ICAO continuity standards in the future, such measures can be referred to. In addition, this paper computes the short-term KASS continuity during the test broadcast period. Although continuity does not meet the ICAO standards, although this test period is too short, further meaningful analysis in the future is required. Additionally, this paper carried out an analysis of the timing and period to systematically calculate the meaningful value of continuity.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2527-2538
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• 2011

The Reliability started for MILitary purposes during World War II in 1942, getting more important for maintenance, safety, etc in modern society. As technologies develop, also international standards for measuring the reliability is advancing. RAMS activities for maintenance, safety verification is material to national railroad. And for this, it needs quick response for the changes of standards. Even now standards are upgrading for developing electronic technologies. Therefore analysis of failure rate's trend about such standards is judged necessary. So We submit a this paper for comparative analysis of changing process standards according to development of electronic technologies and reliability. At first, we compared actual usage ratio of standards for understanding the current state of usage. Based of these state of usage, discuss the major standard. And then, introduced reliability standards's trend, calculation method of failure rate and difference of failure rate calculation standard according to march of time. In this paper, used standards are MIL-HDBK-217F, Telcodia, etc.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1015-1021
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• 2016

Structures, systems, and components (SSCs) important to safety of nuclear facilities shall be designed, fabricated, erected, and tested to quality standards commensurate with the importance of the safety functions. Although SSC classification guidelines for nuclear power plants have been well established and applied, those for research reactors have been only recently established by the International Atomic Energy Agency (IAEA). Korea has operated a pool-type research reactor (the High Flux Advanced Neutron Application Reactor) and has recently exported another pool-type reactor (Jordan Research and Training Reactor), which is being built in Jordan. Korea also has a plan to build one more pool-type reactor, the Kijang Research Reactor, in Kijang, Busan. The safety classification of SSCs for pool-type research reactors is proposed in this paper based on the IAEA methodology. The proposal recommends that the SSCs of pool-type research reactors be categorized and classified on basis of their safety functions and safety significance. Because the SSCs in pool-type research reactors are not the pressure-retaining components, codes and standards for design of the SSCs following the safety classification can be selected in a graded approach.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.45-49
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• 2009

This study is to prepare a reasonable basis for the improvement of the electrical safety management regulation. The standards in domestic and foreign countries for the application of new and renewable energy facilities and other devices are analyzed. Other regulations excluding the electrical safety fields and wide surveys are also carried out. Consequently, it is asked that the classification between normal and self electrical facilities should be clear and deregulation for small businesses has to be followed. This study is showed that standards investigates of receiving equipment below 600V above 75kW, eletrical safety manager employment of manufacturing industry and Mid-night electric power. And, it is showed that consignment permission and Consignment inspection periodic relaxation about wind development equipment below 1,000kW, consignment of Technical Development equipment for new and renewable energy below 250kW.

• Journal of the Korean housing association
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• v.13 no.2
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• pp.47-53
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• 2002

The purposes of this study actually measure to the dimension and the quality of material play equipment's examine whether they meet safety standards or not, and intend to offer basic data to present proper safety standards concerning the dimension of play equipment in the end. The subjects for this study were 59 outdoor playgrounds, 30 among them located in apartment sites and the remainder did in residential districts. The time of actual measurement was in June 1999, and June 2000. Data were analyzed into frequency, percentage, mean, and standard deviation by using SPSSWIN program. The main results were as follows.: First, more than half of playgrounds were assessed for being traffic hazards due to the adjacent streets. And they were hardly equipped with the toilet and drinking water facilities, but were almost equipped with the shade of a tree and benches. Second, it was caused in inconvenience of children's use and difficulty of play equipments'management, since the quality of play equipments materials was consisted of wood or metal. Third, the standards for swing and slide were established in detail and actual measurement's results were suitable to standards'value as well, whereas the standards for seesaw and climber were not in detail and they did not design or install suitably.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.89-95
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• 2017

This study aimed to compare the primary heating energy consumption of regional apartment houses based on the enhanced thermal insulation performance of building envelope standards. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the southern region, the largest regional difference in primary heating energy consumption, is $10.3kWh/(m^2{\cdot}year)$. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the central region is $8.0{\sim}8.5kWh/(m^2{\cdot}year)$ and that of the Jeju region is $0.5kWh/(m^2{\cdot}year)$. These energy consumption differences do not result in building energy efficiency ratings changing. The building energy efficiency ratings have the possibility to be changed.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2000.11b
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• pp.149-153
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• 2000

This study purposed to suggest basic data for establishing safety standards of play equipments by measuring actually the playground facilities which were installed at the playground and examining whether they were suitable to the standards or not. The results which investigated 59 outdoor playground locating in Taegu were as follow. As it examined in this study, the standards for swing and slide were established detailly and actual measurement's results were suitable to standards' value as well. Also the standards for seesaw and climber were not in detail and they were intend to design or install unsuitably in outdoor playground for children.

• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.48-54
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• 2017

This paper presents the motorcycle inspection standards development on the vehicle identification, engine and transmission, tyres and wheels, steering and suspension, and brake system. 187 real-world motorcycles are visually and mechanically inspected according to the developed inspection standards. The non-compliance rate of the vehicle identification is 20.3% and main causes are insecure, damaged, and not clearly visible number plate. The non-compliance rate of the brake system is 15.5% and main cause is failing to meet the brake performance requirements. The motorcycle inspections standards are improved reflecting 187 cases of real-world motorcycle inspection results.