• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.37-40
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• 2008

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.213-219
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• 2010

MCU(Micro Controller Unit) used for the automobiles has been required for improving of the safety and high reliability. Also, the necessity of high performance MCU equipped with high fuel-efficiency has been risen according to increased requests of high fuel-efficiency and improving the occupants safety with the development of intelligent vehicles and future vehicles. The MPC5554 32-bit embedded controller, made by Freescale Semiconductor, specialized in the part of the power train provides the high reliability, fast interrupt process and real-time control. In This paper, the investigation on IPMSM using MPC5554 has been performed. Also SVPWM(Space Vector Pulse Width Modulation) is implemented to the servo system.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.71-74
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• 2007

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate vibration and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.766-770
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• 2011

In this paper, we describe the failure analysis and representation test method that applied high frequency transformer for SMPS through analysing insulation resistance, frequency characteristic, CT analysis, Q-factor atc. And we study the judgement method that a high frequency transformer affects to other beside parts in different condition or environment. According to this method, we devise a plan for the field failure prevent and propose the securing product reliability of high frequency transformer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.348-348
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• 2005

High capacitance MLCC has been enabled through the use of nickel electrodes to produce thinner layers at acceptable costs. High capacitance MLCC devices offer significant advantages to electrolytics such as tantalum and aluminum ; Lower ESR for high frequency applications. Non-polarized. Many process improvement have enabled this technology Higher dielectric constants Thinner dielectric and electrode layers through BME More accurate layer construction. This study is high capacitance MLCC electrical propertics. reliability, Analysis on DOE(Design Of Experiment) of the electical propertics.

• Journal of Applied Reliability
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• v.6 no.2
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• pp.105-113
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• 2006

• Korean Journal of Child Studies
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• v.29 no.5
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• pp.13-30
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• 2008

This study aimed to examine the reliability and validity of a diagnostic instrument to be used to measure the developmental level of very young children (aged birth through 36 months) and to screen young children at risk. The subjects of this study were 861 young children. Data were analyzed by item response distribution, item discrimination, reliability, and validity of the scale. Items reflected the developmental level of each age group. Overall internal consistency was relatively high (Cronbach's ${\alpha}=.90{\sim}.95$), and test-retest (after 2 weeks) reliability was high. Content validity was examined by a panel of experts in the related field. The construct validity as well as the concurrent validity of this instrument was also established.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.625-628
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• 2011

Dynamic sensor network(DSN) technology which is based on swarming flight type air node offers analyzed and acquired information on target data gathered by air nodes in rotation flight or 3 dimension array flight. Efficient operation of dynamic sensor network based on air node is possible when problems of processing time, data transmission reliability, power consumption and intermittent connectivity are solved. Delay tolerant network (DTN) can be a desirable alternative to solve those problems. DTN using store-and-forward message switching technology is a solution to intermittent network connectivity, long and variable delay time, asymmetric data rates, and high error rates. However, all processes are performed at the bundle layer, so high power consumption, long processing time, and repeated reliability technique occur. DSN based on swarming flight type air node need to adopt store-and-forward message switching technique of DTN, the cancelation scheme of repeated reliability technique, fast processing time with simplified layer composition.

• Journal of the Korean Ceramic Society
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• v.29 no.7
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• pp.517-524
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• 1992

For the present study two alumina bodies were prepared. The sinter-aid alumina body(SAA) was made by conventional sinter-process using sintering additives of TiO2 & MgO/CaO and the reaction-bonded alumina (RBA) made from Al-Al2O3 mixed powder. A comparison was made between those two bodies and this investigation seeks to evaluate their microstructure, physical properties and material's reliability as well as their fracture behaviour. In spite of its considerable microstructural densification accompanied by sintering shrinkage, SAA is largely inferior to RBA in fracture strength. However, SAA shows a somewhat higher m-value than RBA in respect to the material's reliability, the Weibull modulus(m). RBA, which has high fracture strength, shows much longer lifetime under static loading than SAA. Though, as with m of fracture strength, the reliability(mt) of lifetime prediction in RBA is less high than of SAA.

• Journal of the Korean Home Economics Association
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• v.36 no.6
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• pp.95-108
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• 1998

This study is the second study which was aimed to validate the Infant/ Toddler Environment Rating Scale(ITERS). The test-retest reliability included 10 infant/toddler classes among 30 national/public and private child care centers in Inchon city which had been observed in the first validation study. The Spearman's correlation coefficient for test-retest reliability was ranged from .52 to .84. In addition, two raters observed 10 family day care centers in Inchon city, where two observers independently rated each centers on the ITERS during a single visit. The Spearman's correlation coefficient for interrater reliability was ranged from.72 to .99 For the second measure of content validity, experts who were working in day care centers and who were graduate students, lecturers, or professors majoring child studies rated the appropriateness of each ITERS items for the provision of high-quality programs for infants and toddlers, using a 1(low) to 5(high) scale. The mean rating was ranged from 2.52 to 4.52. In sum, when the rating scores were analyzed by the type of child care centers, national/public child care centers have better quality than private or family child care centers.