• Title/Summary/Keyword: Core Factor

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CORE-JET BLENDING EFFECTS IN ACTIVE GALACTIC NUCLEI UNDER THE KOREAN VLBI NETWORK VIEW AT 43 GHZ

  • Algaba, Juan-Carlos;Hodgson, Jeffrey;Kang, Sin-Cheol;Kim, Dae-Won;Kim, Jae-Young;Lee, Jee Won;Lee, Sang-Sung;Trippe, Sascha
    • Journal of The Korean Astronomical Society
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    • v.52 no.2
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    • pp.31-40
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    • 2019
  • A long standing problem in the study of Active Galactic Nuclei (AGNs) is that the observed VLBI core is in fact a blending of the actual AGN core (classically defined by the ${\tau}=1$ surface) and the upstream regions of the jet or optically thin flows. This blending may cause some biases in the observables of the core, such as its flux density, size or brightness temperature, which may lead to misleading interpretation of the derived quantities and physics. We study the effects of such blending under the view of the Korean VLBI Network (KVN) for a sample of AGNs at 43 GHz by comparing their observed properties with observations obtained using the Very Large Baseline Array (VLBA). Our results suggest that the observed core sizes are a factor ~ 11 larger than these of VLBA, which is similar to the factor expected by considering the different resolutions of the two facilities. We suggest the use of this factor to consider blending effects in KVN measurements. Other parameters, such as flux density or brightness temperature, seem to possess a more complicated dependence.

A Study on the Development of Evaluation Indicators for the Proposals of National Defense Core-Technology R&D Projects (국방핵심기술 연구개발의 제안서 평가를 위한 평가지표 개발에 관한 연구)

  • Kim, Chan-Soo;Cho, Kyu-Kab
    • IE interfaces
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    • v.21 no.1
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    • pp.96-108
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    • 2008
  • This paper proposes the systematic design approach for developing the evaluation indicators that evaluate the candidate proposals in the national defense core-technology R&D projects. To improve the validity and fairness of the evaluation indicators, the existing evaluation process in a military and a public sector are surveyed and also the existing evaluation system of the core-technology R&D programs for the national defense is analysed and discussed. A new system for the evaluation indicators is designed by using the axiomatic design, factor analysis and the analytic hierarchy process. It is expected that the proposed evaluation indicators contribute to enhance the fairness and the reliability of the evaluation process for the proposal of the national defense core-technology R&D projects.

An Empirical Study on Decision Criteria of Core Banking System Redevelopment Project (은행 기간시스템 전면 재개발 의사결정 기준에 대한 실증적 연구)

  • Lee, Kyung-Jo;Rhew, Sung-Yul;Kim, Sung Kun
    • Journal of Information Technology Applications and Management
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    • v.19 no.4
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    • pp.19-39
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    • 2012
  • Korean core banking system has been redeveloped twice in the last 30 years with big-bang method, but still needs innovation to meet everlasting business changes. The objective of this study is to identify which decision criteria lead to replacement decision of core baning system in spite of its huge investment and accompanying business risk. For the study, we conducted a survey to 64 decision makers working in banks and IT service companies, and analysed the data using factor analysis and multi-regression analysis method of SPSS. As a result, we extracted statistically valid decision model with 4 major decision criteria, which are IT external, IT internal, IT ecology and Executive's will factor. Among them, we concluded only IT internal and IT ecology criteria give significant influence over the replacement decision of existing core banking system.

Balanced Forward-Flyback Converter for High Efficiency and High Power Factor LED Driver (고효율 및 고역률 LED 구동회로 위한 Balanced Forward-Flyback 컨버터)

  • Hwang, Min-Ha;Kang, Jeong-Il;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.5
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    • pp.492-500
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    • 2013
  • A balanced forward-flyback converter for high efficiency and high power factor using a foward and flyback converter topologies is proposed in this paper. The conventional AC/DC flyback converter can achieve a good power factor but it has the high offset current through the transformer magnetizing inductor, which results in a large core loss and low power conversion efficiency. And, the conventional forward converter can achieve the good power conversion efficiency with the aid of the low core loss but the input current dead zone near zero cross AC input voltage deteriorates the power factor. On the other hand, since the proposed converter can operate as the forward and flyback converters during switch turn-on and turn-off periods, respectively, it cannot only perform the power transfer during an entire switching period but also achieve the high power factor due to the flyback operation. Moreover, since the current balanced capacitor can minimize the offset current through the transformer magnetizing inductor regardless of the AC input voltage, the core loss and volume of the transformer can be minimized. Therefore, the proposed converter features a high efficiency and high power factor. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a prototype of 24W LED driver are presented.

The Impact of Grit on University Student's Core Competency in Dental Hygiene Students

  • Park, Soo-Auk;Cho, Young-Sik
    • Journal of dental hygiene science
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    • v.19 no.3
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    • pp.170-180
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    • 2019
  • Background: Recently, competency-based education has been reorganized in the dental hygiene curriculum. In education, non-cognitive factors are emphasized. Grit, the non-cognitive ability to persevere to achieve an individual's long-term goals, is emerging. This study aims to identify the degree of grit and core competencies in students and to investigate the relationship between them and the factors that affect these core competencies. Methods: This study was conducted using 350 dental hygiene students who were randomly assigned a structured questionnaire to complete. The final analysis included 321 students. The survey contents evaluated grit, core competencies, and general characteristics. The difference in the degree of grit and core competencies in conjunction with the general characteristics of the subjects was analyzed using the t-test/Mann Whitney U-test and the ANOVA/Kruskal-Wallis H test. Multiple regression analysis was then conducted to determine the factors affecting the core competencies of the subjects. Results: The difference of 'grit' according to general characteristics was statistically significant in 'major satisfaction', 'relationship', 'perceived academic achievement', 'grade point average (GPA)'. The difference in 'core competency' according to general characteristics was statistically significant in 'grade', 'department selection', 'major satisfaction', 'relationship', 'perceived academic achievement', 'GPA'. Among the sub-areas of 'grit', 'perseverance of effort' showed a high correlation with 'core competency' and was statistically significant. As a result of regression analysis, 'major satisfaction', 'perceived academic achievement' and 'grit' of dental hygiene students had a statistically significant influence on 'core competency'. Meanwhile, 'GPA' was not seen to be statistically significant in 'core competency'. Conclusion: Grit, a non-cognitive factor, had a statistically significant effect on core competency, while the effects on GPA, a cognitive factor, were not statistically significant. Among the sub-factors of grit, 'perseverance of effort' had a statistically significant effect on 'problem-solving competency' and 'academic competency', which are 'core competency' sub factors.

The Influence of the Car Master's Recognized Core Capability level in Achieving Customer Satisfaction: Emphasis on Mediating Effect of Moment of Truth Quality (카마스터의 지각된 핵심역량 수준이 고객만족에 미치는 영향: 고객접점(MOT)품질의 매개효과를 중심으로)

  • An, Seong-Beom;Song, In-Am;Hwang, Hee-Joong
    • Journal of Distribution Science
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    • v.11 no.4
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    • pp.37-49
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    • 2013
  • Purpose - This research identifies the meaning of the core capability level of Car Master and the reason why its service at the Moment of Truth should be demonstrated through empirical cases. It can be seen that this study differs from existing research because it proposes that the recognized core capability level to achieve customer satisfaction should focus on the mediating effect of Moment of Truth quality. This paper examines the effect of Car Master's recognized core capability level on customer satisfaction by using the variables mentioned above. Moreover, this study uses regression analysis to verify that the mediating effect of Moment of Truth quality on Car Master's capability level achieves customer satisfaction. Research design, data, and methodology - First, we present evidence that could apply to Car Master's recognized core capability level by detailing the relationship between customer satisfaction and a structuring factor for Car Master's core capability level. Our proposed research model observes the relationship between the structuring factor of core capability and customer satisfaction. Second, we had an opportunity to define how the core capability and Moment of Truth quality affect customer satisfaction by performing empirical analysis on the partial mediating effect of Moment of Truth quality at a recognized core capability level and Moment of Truth quality affecting customer satisfaction. Results - First, the results indicate that Car Master's recognized core capability level (product professionalism, marketing skill, and reliability) positively affects customer satisfaction. Second, the results show that an ability to listen and a sense of dedication positively affect customer satisfaction, and are among the Moment of Truth quality factors; but performance capability, which is one of the Moment of Truth quality factors, does not positively affect customer satisfaction. These results clearly differ from prior studies focused on Moment of Truth quality and consumer satisfaction. Third, the results show that Moment of Truth quality has a partial mediating effect in terms of the impact of Car Master's recognized core capability level in achieving consumer satisfaction. Conclusions - This research indicates that the company will be able to expand if they investigate and show an interest in more training and education for Car Master. The study verified that outstanding Car Masters show differentiated performance on customer satisfaction at the Moment of Truth in various instances. Thus, we believe that this is the time for a discussion on systematic and empirically recognized core capability levels and the Moment of Truth quality. The study on Car Master's recognized core capability level offers suitable solutions for Car Masters to respond to customers at the Moment of Truth. Further, this study emphasizes the importance of service as a critical factor having a direct relationship with the company's success and failure and contributing to building trust with the customer. Thus, an investment in continuous education and training for Car Master will help the growth of the business.

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A Study on Core Collection through Circulation Statistics of Books in an Academic Library (대학도서관 단행본 대출이력통계를 통한 집중장서에 관한 연구)

  • Yang, Ji-Ann;Nam, Young Joon
    • Journal of the Korean Society for Library and Information Science
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    • v.50 no.3
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    • pp.429-453
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    • 2016
  • This study analyzes circulation patterns of books with checkout transaction count by 11 subject areas, 5 positions, and 5 divisions with a Use Factor developed by Bonn in an Academic Library. 20% of the loan books occupies more than half of circulation and these are regarded as core collection. It proposes a 'Loan books 20/50 rule' that 20% core collection accounts for 50% of its circulation. It analyzes the proportion of core collection from the aspect of each subject area with a use factor, monthly change trend and loan period. It also defines 'book usage' considering checkout frequency of each title and loan period. Circulation patterns of core collection are compared and analyzed in terms of both checkout frequency and book usage. Core collection occupies about more than half of both total checkout transactions and total book usages and they all show a Power Law distribution.

Analyses of on-the-fly generation of spectral superhomogenization factors for multigroup whole core calculation employing pin-wise slowing-down solutions

  • Seungug Jae;Han Gyu Joo
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.1084-1096
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    • 2023
  • On-the-fly(OTF) generation of Spectral Superhomogenization(SSPH) factors is analyzed in the multigroup(MG) whole core calculation employing pin-wise continuous energy(CE) slowing-down solutions. The motivation for the work is to avoid the huge computing time required for the generation of a parametrized SSPH factor library(PSSL) which is used to resolve the angular dependency of MG resonance cross sections, and also to exploit the advantage of flexible choice of a MG structure by using CE slowing-down solutions. Two pin-wise CE slowing-down methods, the equivalent Dancoff cell method and the shadowing effect correction method, are evaluated with the OTF SSPH method. The effectiveness of the OTF SSPH method is examined for various simplified and realistic core problems with various MG structures. It is demonstrated that the computing time overhead of this method is negligible whereas the solution accuracy is considerably enhanced.