• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.235-239
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• 2002

A novel ultra-narrow linewidth DFB laser in the extended FBG ring cavity having kHz linewidth is presented. The method of linewidth compression was realized by introducing an extended fiber ring cavity into the cavity between the external FBG and the Bragg grating inside a DFB laser diode. Optimum optical feedback control was achieved by using an optical circulator and a variable optical attenuator to prevent mode hopping induced by spatial hole burning. To prove the validity of the proposed scheme, a self-heterodyne measurement set-up with fiber delay line of 63 km was utilized for the ultra-narrow linewidth measurement. A 3 dB linewidth of less than 3 kHz was demonstrated, which is resolution limited performance. This linewidth is equivalent to 3 dB linewidth of 2$\times$10$^{-8}$ nm.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.803-806
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• 2003

This paper presents a detailed study of the extended Kalman filter for estimating the rotor speed of an IM drive. The general structure of the Kalman filter is reviewed and the various system vectors and matrices are defined. By including the rotor speed as a state variable, the EKF equations are established from a discrete two axis model of the three-phase induction motor using the software MATLAB/Simulink, simulation of the EKF speed estimation algorithm is carried out for an induction motor drive with direct self control. The investigations show that the EKF is capable of tracking the actual rotor speed provided that the elements of the covariance matrices are properly selected.

• Journal of Korean Society for Quality Management
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• v.41 no.2
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• pp.277-288
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• 2013

Purpose: This study aims to analyze the success factors of information systems and the moderating effect of individual factors in mandatory environment. Methods: In order to test the model, a questionnaire survey is delivered from salespersons of an insurance company in Seoul, Korea. 200 questionnaires are finally analyzed. Structural Equation Modeling (SEM) is adopted to analyze the data and Smart PLS 2.0 is used for examining the moderator effect. Results: The extended model proposed in this paper adopted individual factors and examined their moderator effect among constructs. An empirical test is carried out accordingly in order to test the model proposed in this paper. The results reveal that individual factors (i.e. Computer Self-Efficacy, Anxiety, Personal Innovativeness in IT) have a significant moderating effect on individual performance in the environment of mandatory information system usage. Conclusion: This paper extended the research field of information system success model to information systems in mandatory environment regarding differences of individual factors.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.185-194
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• 2018

The purpose of this study was to investigate the structural relationship between environmental factors, personal factors, ease of use, usefulness and behavioral intention of delivery application by applying the extended Technology Acceptance Model (TAM). An online survey was conducted based on a self-administered questionnaire to a selected sample who had an experience of using delivery application at least once. The survey was conducted in September, 2017. The data obtained was analyzed using SPSS 24.0 for windows and AMOS 24.0. The findings of the study showed that among environmental factors, social influence had a significant effect on perceived usefulness and perceived ease of use and facilitating conditions had a significant effect on perceived ease of use only. Among personal factors, anxiety had a significant effect on perceived usefulness, while innovation had a significant effect on perceived ease of use. Both of perceived usefulness and perceived ease of use had a significant effect on behavioral intention. This study suggests the importance of environmental and personal factors for increase of behavioral intention of delivery application.

• Korea Journal of Hospital Management
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• v.11 no.4
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• pp.37-62
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• 2006

This study investigates the antecedents of knowledge sharing behavior focusing on the individual level factors in an assumption that the behavior is initiated from the individual level decisions. A hypothesis that the relation between personality trait and behavior is mediated by the social-cognitive constructs contained in the Theory of Planned Behavior(TPB) is tested. For the study, we suggest a TPB extended model that extends original TPB model by including conscientiousness facet of FFM(Five Factor Model). This study uses a cross-sectional design. Data were collected from a self-reported survey on 197 nurses in a tertiary hospital. The results showes a significant positive relationship between the conscientiousness facet of FFM and knowledge sharing behavior. In the TPB extended model, the conscientiousness facet has significant direct effects on all the constructs of original TPB model. Of the TPB exogenous constructs, the social norm construct alone has a significant effect on intention and the perceived behavioral has a direct significant effect on the knowledge sharing behavior. These results confirm the importance of conscientiousness in predicting knowledge sharing behavior and clarify the characteristics of knowledge sharing behavior as a contextual, job oriented behavior in a workplace. We conclude that personality trait as conceptualized in the FFM needs to be integrated into TPB model in explaining the knowledge sharing behavior. Based on these results theoretical and practical implications are discussed.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.60.1-60.1
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• 2015

High energy photons and mechanical energy produced by the process of star formation result in copious FIR molecular and atomic lines, which are important coolants of the system. Photons thermally or mechanically induced could dissociate water in the dense envelope to change relative abundances among the species of O, OH, and H2O. Here we analyze OH emission lines toward embedded young stellar objects (YSOs) observed as part of the Herschel open time key program, 'Dust, Ice, and Gas In Time (DIGIT)' in order to study the physical conditions of associated gas and the energy budget loaded on the OH line emission. According to our analysis of the Herschel/PACS spectra, OH emission peaks at the central spaxel in most of sources, but several sources show spatially extended emission structures. In the extended emission sources, the distribution of OH emission is correlated with that of [OI] emission and extended along the outflow directions. Considering the diversity of source properties, ratios between detected OH lines are relatively constant among sources. In addition, each OH line has strong correlation with bolometric luminosity. In order to determine the physical conditions of YSOs, we adopt several methods for the analysis of the OH lines: rotational diagram, non-LTE LVG analysis, and a 2-D PDR code. From the simple LVG analysis, we find that the thermal solution with the dense ( > $10^7cm^{-3}$) and warm ( ~ 100 K) OH gas reproduces the ratios of detected OH lines. However, our self-consistent PDR 2-D model, which can deal with the IR-pumping effect from the central protostar as well as the warm dust in situ, cannot fit the observational results, suggesting that an irradiated shock model is necessary for a better interpretation.

• Structural Engineering and Mechanics
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• v.68 no.3
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• pp.299-312
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• 2018

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.105-112
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• 1998

In this paper, we propose a ESP(Extended Scan Path) architecture for multi-board testing. The conventional architectures for board testing are single scan path and multi-scan path. In the single scan path architecture, the scan path for test data is just one chain. If the scan path is faulty due to short or open, the test data is not valid. In the multi-scan path architecture, there are additional signals in multi-board testing. So conventional architectures are not adopted to multi-board testing. In the case of the ESP architecture, even though scan path is either short or open, it doesn't affect remaining other scan paths. As a result of executing parallel BIST and IEEE 1149.1 boundary scan test by using the proposed ESP architecture, we observed that the test time is short compared with the single scan path architecture. By comparing the ESP architecture with single scan path responding to independency of scan path, test time and with multi-scan path responding to signal, synchronization, we showed that the architecture has improved results.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.407-417
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• 2010

In Basel II compliance, internal rating systems are allowed for banks to enhance the self control and the validation of the system are getting more important. The validation methods are composed of qualitative test and quantitative test, three basic standards of which are discriminatory power, stability and calibration. The aim of this article is to review the quantitative tests for calibration and find a new method for it. These methods for discrimination between forecasted PD and observed PD include binomial test, chi square test, Brier score, traffic lights approach, normal test and extended traffic lights approach. We introduce a modified extended traffic lights approach considering asset correlations.

• The Journal of Information Systems
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• v.26 no.3
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• pp.313-337
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• 2017

Purpose Financial technology, also known as FinTech, is conceptually defined as a new type of financial service which is combined with information technology and other traditional financial services like payments, investments, financing, insurance, asset management and so on. Most of the studies on FinTech services have been conducted from the viewpoint of technical issues or legal and institutional studies, and few studies are conducted from the health belief perspectives and security behavior approaches. In this regard, this study suggest an extended information protection behavior model. Design/Methodology/Approach The Health Belief Model (HBM), the Protection Motivation Theory (PMT), and the Technology Threat Avoidance Theory (TTAT) were employed to identify constructs relevant to information protection behavior of FinTech services. A new extended information protection behavior model in which the influence factors of information protection behavior (i.e., perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, subjective norms) affect perceived threats and perceived responsiveness positively, leading to information protection behavior of FinTech users eventually. This study developed an extended information protection behavior model to explain the protection behavior intention in FinTech users and collected 272 survey responses from the mobile users who had experiences with such mobile payments and FinTech services. Findings The finding of this study suggests that the influence factors of information protection behavior affect perceived threats and perceived responsiveness positively, and information protection behavior of FinTech users as well.