• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.57-64
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• 2003

The liquefaction potential of saturated sands under seismic loading conditions has been carefully considered by many investigations. Typical of these investigations is the laboratory determination of cyclic strength of sands by means of cyclic triaxial tests. This study was conducted to investigate the effects of the method of sample preparation on the liquefaction characteristics of remolded samples of saturated uniform sands. Cyclic triaxial tests were performed on saturated uniform sand compacted to the same density by 3 different procedures of pluvial compaction through air, pluvial compaction through water and vibratory compaction. It was validated that the cyclic stress ratio of remolded saturated uniform sands by different compaction procedures at the same density was very different.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.59-66
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• 2008

Korea Electric Power Research Institute in charge of the power IT project "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology" is performing system verification. Breaker Failure protection IED can operate protection activity by communicating with other IEDs such as T/L IED, owing to IEC 61850 international standard and digital substation automation system. Accordingly, IED testing process should be changed from the conventional way by electrical contact test on individual IED to system based testing method by network communication. This paper describes how to test BF IED based on substation automation system and testing procedures using UML, which is used to implement S/W design.

• Journal of Korean Society for Quality Management
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• v.49 no.1
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• pp.47-60
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• 2021

Purpose: This study proposes methods and procedures for evaluating imaging security systems quality of cabinet x-ray screening system to enhance performance certification technology. Also, conducted a comparative analysis of the literature of test-kit for imaging security quality evaluation. Methods: Comparative analysis of the test-kits and related documents for image quality assessment of cabinet x-ray screening equipment. This allows assessment items were selected and the methods for each assessment item were proposed. In addition, the configuration method of the assessment team was established by applying the technology readiness assessment(TRA). Results: Four of the assessment items were selected when estimate image quality by a comparative analysis of literature. For each assessment item, the evaluation method and minimum level of availability were determined. Finally, this paper proposes an imaging quality assessment of cabinet X-ray imaging security systems. Conclusion: Development of imaging security systems evaluation procedures for cabinet X-ray screening systems can be help improve performance certification of aviation security equipment.

• Journal of Korean Clinical Nursing Research
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• v.27 no.2
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• pp.179-186
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• 2021

Purpose: The purpose of our study was to identify the bleeding risk factors and to validate the safety of shortening the bed rest time after bone marrow examination in pediatric hemato-oncologic patients. Methods: From July 2019 to September 2020, 145 patients were enrolled from a single center. Medical records were reviewed retrospectively. Descriptive statistics were presented, and the data were analyzed using 𝑥²-test, Fisher's exact test, and a logistic regression. Results: After two hours of bed rest, most of the patients (91.7%) did not have bleeding complications, and only 8.3% of the patients had a minor bleeding. The rate of major bleeding complications, including hematoma, retroperitoneal hemorrhage rate was zero. The bleeding complications was frequently found on bilateral procedures than unilateral procedures and the difference were statistically significant (p<.05). Conclusion: Two hours of bed rest time after bone marrow examination could be safe and adequate in pediatric hemato-oncologic patients.

• Korean Journal of Child Studies
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• v.29 no.6
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• pp.163-176
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• 2008

The purpose of this study was to develop a standardized performance style Multiple Intelligences Test for preschoolers(MIT-P). A total of 270 preschoolers(3~5-years-old) participated in this study. Tools and procedures were developed to measure performance in 7 areas of multiple Intelligences(linguistic, mathematical, science, social, music, art and kinesthetic). The final test set included 138 items. Reliability of the MIT-P was relatively high(Cronbach alpha =.92). Intercorrelations among measures of the 7 areas indicated construct validity. Based on these results, the pilot study of MIT-P is considered adequate to form the basis of a new test that would help teachers and parents to identify children's strengths and weaknesses and may be useful for educational planning.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.108-117
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• 1998

Testing and evaluation was carried out to certify quality assurance of localized engine parts using accelerated mission test method, which has been used to verify qualification or substantiation of the developed engine, improved engine components and engineering changed parts since 1976. Because AMT is not a familiarized testing for quality assurance of engine and localized engine parts in korea, through this testing and evaluation, it is presented the concepts, test procedures and evaluation method of AMT and is proposed the possibility of execution AMT, as a tool for qualification or substantiation test of a development engine or components.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.124-127
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• 2004

This study is to investigate the bond characteristics of glass fiber reinforced polymer(GFRP) reinforcing bars in concrete by pullout test experimentally. Three different types of GFRP bars with different surface deformations were considered in this study. Also, standard deformed steel reinforcing bar with or without epoxy-coating were included for the comparisons of bond strength. All test procedures including specimens preparation, test apparatus and measuring devices were made according to the recommendation of CSA(Canadian Standards Association) Standard S806-02. From the test results, it was found that small surface indentations contributed to increase the bond strength of GFRP bar significantly. Based on the limited test results till now, the bond strength of GFRP bar with sand-coated deformation commercially available in foreign market is around $80\%$ of that of steel deformed bars.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.205.1-205.1
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• 2011

This study concerns a low head and kaplan turbine efficiency measurement using the acoustic scintillation flow meter(ASFM). The ASFM is one of absolute discharge measurement methods because it measures velocity-area of discharge with couples of transducers. This study shows that the highest efficiency of turbine is 87.7% and the efficiency is 85.8% in the rated output(600kW). The test result is reliable because the efficiency trend from this test is similar to the result of index test conducted in 1986. In this paper, the principle, measurement methods, application and test procedures of the test are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.220-223
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• 2007

Acoustic test of the payload fairing of Korea satellite launch vehicle was conducted to verify the performance of acoustic protection system installed inside the payload fairing. This paper briefly introduces the acoustic test procedures and its results. Overall 148 dB acoustic loads were exerted on the payload fairing structures which mated with the upper stage structure of the launch vehicle. In order to verify the increase of insertion loss by the acoustic protection system, two kinds of test were performed. One is conducted with acoustic protection system and the other without acoustic protection system. Internal acoustic loads as well as external ones were measured and the measured insertion losses were compared with the requirement. The results showed that the acoustic protection system increases the insertion loss by more than 6 dB above 125 Hz. They also indicated that some design modification of Helmholtz resonator array is required to increase the insertion loss at a cavity resonant frequency.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.48.1-48.1
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• 2011

In this presentation, We monitored weather data, such as global irradiance, ambient temperature, temperature of PV module, relative humidity and windspeed for 2 years, for determining accelerated test condition. then, we determined the temperature limit of accelerated test through weather data and FEM analysis. Detailed procedures will be summarized in this work. After analysing outdoor stress such as thermal stress, we decided main failure modes and mechanisms of PV module, especially solder joint of ribbon wire. we carried out the measurement of material properties such as thermal expansion coefficient for planning of accelerated test. we designed accelerated test based on FEM analysis results. we carried out thermal cycling test with 1 cell mini module for 3 months. We monitored the change of electrical performance every 1 week such as Voc, Isc, Pmax, etc. and then, we analized the ribbon wire/electrode intefaces. Detailed results will be summarized in this work.