• 전기학회논문지
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• 제57권4호
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• pp.576-581
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• 2008

Electricity Market in Korea can't provide locational price signal through energy price because energy market is CBP(Cost Based Pool) using uniform price. Generators don't want to locate in a densely populated load area(like the metropolitan area). Because they are paid more fixed cost in metropolitan area. This situation has loss and congestion occurred in power system. However energy market without price signal can't lead generator to the metropolitan. So, market participants should be provided price signal through the transmission price instead of energy price. This paper proposes transmission pricing method considering reliability cost in order to offer price signal. Also, it proposes the method to allocate the transmission cost to each transmission line user through a fair and a reasonable manner. The transmission price is decided by the reliability value of each line. If a transmission line of high reliability value is broke, users using that line will get a loss and a discomfort. So, it is fair that users using a transmission line of high reliability value pay more than the other users. Also, it is reasonable that a transmission line owner get paid more form users using that line.

• 대한금속재료학회지
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• 제50권10호
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• pp.721-728
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• 2012

This paper evaluates the reliability of creep rupture life under service conditions of Alloy 617, which is considered as one of the candidate materials for use in a very high temperature reactor (VHTR) system. A Z-parameter, which represents the deviation of creep rupture data from the master curve, was used for the reliability analysis of the creep rupture data of Alloy 617. A Service-condition Creep Rupture Interference (SCRI) model, which can consider both the scattering of the creep rupture data and the fluctuations of temperature and stress under any service conditions, was also used for evaluating the reliability of creep rupture life. The statistical analysis showed that the scattering of creep rupture data based on Z-parameter was supported by normal distribution. The values of reliability decreased rapidly with increasing amplitudes of temperature and stress fluctuations. The results established that the reliability decreased with an increasing service time.

• The Journal of Korean Physical Therapy
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• 제34권5호
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• pp.234-241
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• 2022

Purpose: The Cardiac Rehabilitation scale (INCR scale) is a verified measure worldwide. The scale measures the extent to which cardiac rehabilitation meets the various needs of the participating patients and determines how education related to heart disease and rehabilitation satisfies their preferences. The current study applied the INCR scale to verify and develop it for use in Korea by conforming to Korean culture and language. Methods: The Korean version of the INCR scale was created after a six-step process in accordance with the international questionnaire translation law. The Korean version of the INCR scale was assessed in 45 cardiac rehabilitation patients (29 males, 16 females). Internal consistency was verified using Cronbach's alpha. Test-re-test reliability and interrater reliability were verified using the intraclass correlation coefficient (ICC). Content validity was selected to verify the validity. Results: The content validity index of the Korean version of the INCR scale was high, with an average of 0.93. Cronbach's Alpha for Internal consistency also revealed high reliability of 0.89 in all 10 categories. The interclass correlation coefficient of the test-re-test and interrater reliability scores were 0.95 and 0.81, respectively. Conclusion: Our results indicate that the Korean version of the INCR scale would be instrumental in the clinical setting to determine the knowledge, educational needs, and preferences of patients participating in cardiovascular disease and cardiac rehabilitation.

• 마이크로전자및패키징학회지
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• 제12권1호
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• pp.9-16
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• 2005

This paper presents the development of new anisotropic conductive adhesives with enhanced thermal conductivity for the wide use of adhesive flip chip technology with improved reliability under high current density condition. The continuing downscaling of structural profiles and increase in inter-connection density in flip chip packaging using ACAs has given rise to reliability problem under high current density. In detail, as the bump size is reduced, the current density through bump is also increased. This increased current density also causes new failure mechanism such as interface degradation due to inter-metallic compound formation and adhesive swelling due to high current stressing, especially in high current density interconnection, in which high junction temperature enhances such failure mechanism. Therefore, it is necessary for the ACA to become thermal transfer medium to improve the lifetime of ACA flip chip joint under high current stressing condition. We developed thermally conductive ACA of 0.63 W/m$\cdot$K thermal conductivity using the formulation incorporating $5 {\mu}m$ Ni and $0.2{\mu}m$ SiC-filled epoxy-bated binder system to achieve acceptable viscosity, curing property, and other thermo-mechanical properties such as low CTE and high modulus. The current carrying capability of ACA flip chip joints was improved up to 6.7 A by use of thermally conductive ACA compared to conventional ACA. Electrical reliability of thermally conductive ACA flip chip joint under current stressing condition was also improved showing stable electrical conductivity of flip chip joints. The high current carrying capability and improved electrical reliability of thermally conductive ACA flip chip joint under current stressing test is mainly due to the effective heat dissipation by thermally conductive adhesive around Au stud bumps/ACA/PCB pads structure.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권3호
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• pp.166-173
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• 2009

The reliability of hafnium oxide gate dielectrics incorporating lanthanum (La) is investigated. nMOSFETs with metal/La-doped high-k dielectric stack show lower $V_{th}$ and $I_{gate}$, which is attributed to the dipole formation at the high-k/$SiO_2$ interface. The reliability results well correlate with the dipole model. Due to lower trapping efficiency, the La-doping of the high-k gate stacks can provide better PBTI immunity, as well as lower charge trapping compared to the control HfSiO stacks. While the devices with La show better immunity to positive bias temperature instability (PBTI) under normal operating conditions, the threshold voltage shift (${\Delta}V_{th}$) at high field PBTI is significant. The results of a transconductance shift (${\Delta}G_m$) that traps are easily generated during high field stress because the La weakens atomic bonding in the interface layer.

• Physical Therapy Rehabilitation Science
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• 제5권3호
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• pp.155-161
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• 2016

Objective: This study aimed to investigate the reliability and validity of a personal computer-based muscle viewer (PC-BMW) compared with that of a portable ultrasound (P-US) for measuring upper trapezius (UT) and transversus abdominis (TrA) muscle thickness at rest and during contraction. Design: Observational inter-rater reliability study. Methods: Fifty-five healthy participants (25 men, 30 women) participated in this study. PC-BMW and P-US were randomly measured at the UT and TrA muscles. Two examiners randomly obtained the images of all participants in 3 test sessions lasting 2 days. Intra-class correlation coefficients (ICCs), standard error of measurement, contraction ratio, and correlation were used to estimate reliability and validity. Pearson's correlation coefficients were used to analyze the relationship between muscle thickness measures taken from PC-BMW and P-US. Results: The intra-rater reliability ICCs of UT and TrA muscle thickness for the PC-BMW were >0.995, indicating excellent reliability. Inter-rater reliability ICCs for the PC-BMW ranged from 0.963 to 0.987. The P-US also exhibited high reliability. A high correlation was found between the measurements of the two muscles in PC-BMW and P-US (p<0.01). Conclusions: PC-BMW provides clear and excellent images, is pocket-sized and less expensive than a conventional ultrasound imaging system. PC-BMW can be utilized variously and has the advantage of rehabilitative ultrasound imaging. More research is needed to evaluate the utility of PC-BMW for rehabilitation.

• 한국신뢰성학회지:신뢰성응용연구
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• 제8권3호
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• pp.125-134
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• 2008

Global Positioning System(GPS) is prospects item of information infrastructure with internet. Global Positioning System module made by domestic have high technology, but its international competitive power is very weak because of reliability. In this paper, we compare domestic products with foreign advanced products exactly, and confirm excellence of domestic products.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.682-687
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• 2005

High quality power supplying of power distribution system in electric railway system is the important function. Power feeding system is complicated witch is compose with distribution line, circuit break, protection facilities and so on. Among this components, role of substation is most important for elevation of reliability in electric power system. Therefore, the enhanced reliability considering the preventive inspection, repair work, replacement is necessary. In this study, a proposed the enhanced reliability method through a calculation of fault probability in power feeding system.

• 마이크로전자및패키징학회지
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• 제22권3호
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• pp.1-7
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• 2015

In this study, properties of Pb-free solders for automotive electronics parts were discussed. Lead-free solders for electronics became important after RoHS (Restriction of the use of certain Hazardous Substances) to avoid environmental pollution. Also the growing electronic rate in automotive parts and ELV (End-of Life Vehicles) make Pb-free solder for automotive electronics to be inevitable trend. Definitely, Pb-free solder for automotive electronics should have good wettability, basic strength, but need more reliability than other solders, since it has harsh condition like high temperature, humidity and engine vibration. Thus, shear strength test, thermal shock, drop test and many others are needed to ensure the high reliability. This study describes the properties and requirements of Pb-free solders for automotive electronics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.328-333
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• 2004

With the introduction of KTX, in my view it is necessary to secure the reliability of high-speed trains, make them stabilized at the earliest moment possible, and completely digest them as our own system for the purpose of being second to none in the area of railroad business. I am going to study in this thesis through analysis of train failures by help of MKBSF calculation, breaking from the convention in maintaining the high-speed trains, in order to establish and apply the computerized system called as RCM (Reliability Centered Maintenance), foster manpower in charge of the reliability maintenance, and realize the scientific and efficient maintenance covering the whole field of maintenance. Depending on how efficiently and scientifically we can perform the maintenance activities, we will be able to not only reduce the maintenance cost but also ensure the railroad security, and as a natural consequence improve the railroad image much better.