• Nuclear Engineering and Technology
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• v.44 no.5
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• pp.543-550
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• 2012

The decrease in the fracture toughness of ferritic steels in a reactor pressure vessel is an important factor in determining the lifetime of a nuclear power plant. A surveillance program has been in place in Korea since 1979 to assess the structural integrity of RPV steels. In this work, the surveillance data were collected and analyzed statistically in order to derive the empirical relationship between the embrittlement and strengthening of irradiated reactor pressure vessel steels. There was a linear relationship between the yield strength change and the transition temperature shift change at 41 J due to irradiation. The proportional coefficient was about $0.5^{\circ}C$/MPa in the base metals (plate/forgings). The upper shelf energy decrease ratio was non-linearly proportional to the yield strength change, and most of the data lay along the trend curve of the US results. The transition regime temperature interval, ${\Delta}T_T$, was less than the US data. The overall change from irradiation was very similar to the US results. It is expected that the results of this study will be applied to basic research on the multiscale modeling of the irradiation embrittlement of RPV materials in Korea.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.4
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• pp.69-81
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• 2020

Since airline safety depends significantly on the role of pilot, the importance of airlines' training qualified pilots and investing in the training program grows. This study aims to analyze the determinants of the commercial airline pilot competencies during the transition course. To this purpose, one-year training evaluation results of 215 new airline pilots in the JET transition course of Company K in 2019 are studied with correlation coefficient analysis, factor analysis, ANOVA, and regression analysis. Undergraduate major and Uljin-trained pilots show higher final-stage scores in PROC, AUTO, and CRM. Due to Uljin-trained pilots' higher first-stage scores, their score increase during the course is limited. Uljin-trained pilots' MANUAL scores in the final stage are lower than those of undergraduate major and overseas-trained pilots. Influence of trained location is found greater than English competency, undergraduate GPA, and ground school scores on commercial airline pilot competency evaluation scores during the program. The results will be useful in establishing scenario-based training focusing on different background to apply competency-based training and assessment.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.147-150
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• 2002

HPSL(High Pressure Sodium lamp)have attracted much attention in recent years, because they offer high luminous efficiency and very long life. Recently, AC-DC converters have been widely as power factor improvement circuits in the power conversion equipment An application of the ZVT-PWM(Zero Voltage Transition Pulse Width Modulation) boost converter, which has great advantage on miniaturization and high power density, to the power factor improvement circuit of the HPSL inverter are described to identify the power factor correction characteristics of the inverter. In this paper the series-parallel resonant inverter(electronic ballast) for driving a HPS lamp is discussed. Finally, a power factor corrector is cascaded in front of the electronic ballast. Consequently, a high power factor above 0.99 and low THD on the line current can be achieved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.1-10
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• 2009

Bus delay time is occurred as the result of traffic condition and important factor to predict bus arrival time. In this paper, transition probability matrixes between bus stops are made by using Markov Chain and it is predicted bus delay time with them. As the results of study, it is confirmed a possibility of adapting the assumption which it has same bus transition probability between stops through paired-samples T-test and overcame the limitation of exiting studies in case there is no scheduled bus arrival time for each stops with using bus interval time. Therefore it will be possible to predict bus arrival time with Markov Chain.

• Fashion & Textile Research Journal
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• v.21 no.6
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• pp.743-753
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• 2019

This study investigates differences in demographic characteristics, shopping orientation, perceived risk, and satisfaction after purchase among consumer types. This study classifies consumer types according to their channel transition behaviors between the online and offline channels with a focus on the steps of information research and buying decision in buying decision-making process. The four consumer groups are as follows: off-off type (offline research-offline purchase), on-on type (online research-online purchase), on-off type (online research-offline purchase) and on/off-off type (online and offline research-offline purchase), off-on type (offline research-online purchase) and on/off-on type (online and offline research-online purchase). Data were collected from adults over 20 years old who had bought clothes within one year. The questionnaire was carried out from July, 2019 using a professional internet research panel; in addition, 500 sets of useful data were analyzed by descriptive statistics, factor analysis, reliability analysis, chi-squared test, ANOVA and Duncan-test using SPSS 21.0. The findings showed significant differences among the classified consumer groups for consumer demographics, shopping orientation, perceived risk, and purchase after satisfaction. The results imply that consumers show a variety of channel transition behaviors based on demographic variables, shopping orientation, and perceived risk. Understanding and adapting to consumer purchase behaviors will allow company distribution channels to be effectively managed and eventually increase consumer satisfaction as well as company sales volume.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5902-5909
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• 2011

In this paper, we propose a new method to detect abrupt and gradual shot transitions of video data by using certainty factors. The abrupt transitions denotes cuts and the gradual transitions fade in, fade out, dissolve, horizontal wipes, vertical wipes, Barn Doors, and Iris Rounds. The suggested method first extracts representative features for each shot transition and determines corresponding shot transitions by integrating all the extracted features and inferring adequate transitions. To verify the performance of the proposed shot transition method, experimental results show that the suggested method can detect shot transitions more accurately than existing methods.

• Korean Institute of Interior Design Journal
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• v.23 no.6
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• pp.178-186
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• 2014

Recently, a lower levels space has turned into a mediating space where people can experience urban spaces directly and it has revitalized communication between the city and company and also it has changed itself newly. In addition, this space which is connecting interior and exterior spaces of company's buildings can attract people living in the downtown as shock-absorbing and transitional space and it is getting more important part in urban context these days. Through case studies of corporate office space planning characteristics derived lower levels and to provide direction for the lower levels of the corporate office space planning purposes of the present study. Therefore, I establish the concept of the public good corporate office space and transition space, the concept of transition through the first Theoretical Methods. I investigate the properties of the transition area is used as the target for completion of the current construction culture destination since 2000, winning the corporate office, I have been talking about the characteristics of the corporate office along the lower part of the last PPS assessment criteria to apply to the building. PPS by applying an assessment factor can be derived for building enterprise case studies and analysis of the results the following conclusions about the use of publicity and transition space. First, lower levels of corporate office space had been applied to the use and activity in a very important project characteristics. Second, corporate office space, lower levels of access and linkages are important. Finally, in terms of public characteristics transition space is a important characteristic for low-rise space of headquarter buildings.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.169.2-169.2
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• 2015

$VO_2$ is a well-known a metal-to-insulator-transition (MIT) material, accompanied with a first order structural phase transition near room temperature. Because of the structural phase transition and the MIT occur near a same temperature, there is an ongoing argument whether the MIT is induced by the structural phase transition. $VO_2$ exhibits a relatively weak anti-oxidization ability and can be oxidized to higher-valence oxides (e.g., $V_4$ $O_7$ or $V_2$ $O_5$) when annealed at a high temperature in an oxygen-rich atmosphere. We fabricated $VO_2$ films on $Al_2$ $O_3$ (0001) substrates using a DC magnetron sputtering deposition process with carefully control the $O_2$ percentage in an atmosphere. X-ray diffraction measurements from the films showed only (0l0) peaks with no extra peaks, indicating b-oriented films. The temperature-dependent local structural properties of $VO_2$ films were investigated by using in-situ X-ray absorption fine structure (XAFS) measurements at the V K edge. XAFS revealed that the structural phase transition was occurred nearly $70^{\circ}C$ for heating process and reproducible. Resistance measurements as a function of temperature (R-T) demonstrated that the resistance of $VO_2$ films was changed by a factor of 4 near $75^{\circ}C$ which was higher than $68^{\circ}C$ reported from a $VO_2$ bulk. We will discuss the MIT of $VO_2$ films, comparing with the local structural properties determined by XAFS measurements.

• Journal of Information Technology Services
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• v.23 no.3
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• pp.17-37
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• 2024

This study explores the tendency of corporations and organizations to continue with their current processes despite having incentives for better Information Technology (IT) innovation or transition. In this context, the study argues that organizations may struggle with 'outsourcing inertia,' a well-known concept referring to an organization's deficient adaptability to environmental changes, particularly defined here as the organization's slow adaptation to changes in outsourcing levels. To verify this, the study analyzes how key variables identified from existing IT Outsourcing (ITO) decision-making research and recent studies on cloud computing transitions actually affect a firm's transition intentions. In the process, this study investigates the moderating effect of a firm's outsourcing inertia, utilizing the Technology-Organization-Environment (TOE) framework and the Push-Pull-Mooring (PPM) model based on migration theory to propose a research model. The study aims to contribute to finding strategic approaches necessary for facilitating IT innovation and transition by understanding the impact of outsourcing inertia on the decision-making process related to IT outsourcing. It is important to note that the majority of domestic conglomerates own IT subsidiaries, which significantly influence the process of transitioning to cloud computing. Nevertheless, research on the impact of IT subsidiaries on cloud computing transition is relatively scarce. Based on this background, this study proposes that IT subsidiaries within domestic conglomerates can act as a significant mooring factor of organizational inertia in the decision-making process for adopting cloud computing. Through this, the study seeks to provide strategic insights for overcoming organizational inertia faced by IT subsidiaries during the cloud computing transition process.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.265-265
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• 2018