• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.252-252
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• 2017

• IE interfaces
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• v.24 no.4
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• pp.314-322
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• 2011

This study analyzes a relationship between Data Envelopment Analysis(DEA) efficiency scores and a normalization index in order to examine the validity of DEA models. A normalization index concerned in this study is 'sales per R&D project fund' which is regarded as a crucial R&D project performance evaluation index in practice. For this correlation analysis, three distinct DEA models are selected such as DEA basic model, DEA/AR-I revised model(i.e. DEA basic model with Acceptance Region Type I constraints) and Super-Efficiency(SE) model. Especially, SE model is adopted where efficient R&D projects(i.e. Decision Making Units, DMU's) with DEA efficiency score of unity from DEA basic model can be further differentiated in ranks. Considering the non-normality and outliers, two rank correlation coefficients such as Spearman's ${\rho}_s$ and Kendall's ${\tau}_B$ are investigated in addition to Pearson's ${\gamma}$. With an up-to-date empirical massive dataset of n = 482 R&D projects associated with R&D Loan Program of Korea Information Communication Promotion Fund in the year of 2011, statistically significant (+) correlations are verified between the normalization index and every model's DEA efficiency scores with all three correlation coefficients. Especially, the congruence verified in this empirical analysis can be a useful reference for enhancing the practitioner's acceptability onto DEA efficiency scores as a real-world R&D project performance evaluation index.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.91-91
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• 2004

• Journal of Environmental Science International
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• v.6 no.1
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• pp.9-16
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• 1997

We investigated and analysed the actual conditions and characteristics of railroad noise levels for 17 sites in the vicinity of the Seoul-Pusan Line. The results i,we summarized as follows : 11 Railroad noise level ranged to 64 ~ 74 $L_{eq}$ dB(A) at day time and ranged to 60 ~ 72 $L_{eq}$ dB(A) at night time. 21 Increased night noise level depend on the increase of trains passing at night time. 31 The major factor of Increased noise level in the vicinity of stations are using loudspeakers and stream whistle on trains. 4) Decreased effect of noise according to distance is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$=$78.59^{X-0.056}$, n =25, r=-0.994, s.e. =1.007 $P_{av}$ = $105.68X^{-0.073}$, n =25, r =-0.997, s.e. = 1.007 Also increased and decreased effect of noise according to floor in apartment Is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$ = $64.238X^{0.0567}$, n = 39, r = 0.787, s.e. = 1.004 $P_{av}$ =79.963X0.0524, n =39, r =0.689, s.e. = 1.056 5) Average noise level in high floor is over 70 $L_{eq}$ dB(A) at day and night time. so more detailed soundproofing countermeasured in high floors apartment is required.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.794-803
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• 1987

In this paper, the SPICE 2.G6 JFET subroutine and other related subroutines are modified for circuit simulation of GaAs MESFET IC's. The hyperbolic tangent model is used for the drain current-voltage characteristics of GaAs MESFET's and derived channel-conductance and drain-conductance model from the above current model are implemented into small-signal model of GaAs MESFET's. And, device capacitance model which consider after-pinch-off state are modified, and device charge model for SPICE 2G.6 are proposed. The result of modification is shown to be suitable for GaAs circuit simulator, showing good agreement with experimetal results. Forthermore the DC convergence of this paper is better than that of SPICE 2.G JFET subroutine. GaAs MESFET model in this paper is applied for both depletion mode GaAs MESFET and enhancement-mode GaAs MESFET without difficulty.

• The Journal of Information Systems
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• v.28 no.3
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• pp.203-225
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• 2019

Purpose The purpose of this study is to empirically verify an ePortfolio success model which shows the structural causal relationships among the basic modeling constructs. We developed the success model based on DeLone and Mclean(2003) from IS perspective and on Balaban et al(2013) from ePortfolio perspective. And we are focused on the success of ePortfolio system designed for college students and professors. Design/methodology/approach Structural equation modeling techniques were applied to data collected 375 users of the ePortfolio system, K-Folio, at least one semester during one academic year. The structural model was analyzed using a Lisrel 8.54 statistical program. Findings The followings are the findings of the study. First, the constructs of IS success model are well applied to ePortfolio for college education. Second, the proposed model which has direct causal relationships from ePortfolio's quality to performance is more significant than the D&M and Balaban's model(2013). Third, the information quality among ePortfolio quality constructs does not have effect on system usability and performance. It means that information contents' quality issued by professor or system manager is not satisfied with the students yet. Finally, by using indirect analysis of structural equation model, we found that the ePortfolio operation manager should focus on ensuring system maintenance activities and providing fast and accurate services for improving ePortfolio performance.

• Cross-Cultural Studies
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• v.25
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• pp.549-596
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• 2011

This paper aims to introduce some useful multimedia freewares, and also support Chinese instructor with discussing how to operate them for instructional design of multimedia language learning class. For this aims, this paper consists of three parts: First, instructional design. This part is focused to what kind of instructional model to be based on, for example, Dick & Carey model, ADDIE model, ASSURE model etc. This part introduces these models, and modifies ADDIE and ASSURE model to D.D.A.I.E.S and S.S.A.U.R.E.S as 'A(nalysis)' in these model may apply to the next 'D(evelopment)' on ADDIE, 'S(elect Methods, Media and Materials)' on ASSURE in the practical Chinese class. Second, Programme: What to use. This part is focused to what kind of free software we can use. In the web site online, there are huge free softwares so we usually hesitate to select and also don't know how to operate even though selected one of them. This part, accordingly, introduces ten of useful freewares and compares each other in terms of usefulness for Chinese instructors. Third, Programme: How to use. It is of no use just to know what to use but not to know how to operate, so this part describes how to use freewares like a kind of manual in detail as far as possible. In conclusion, we hope more Chinese instructors to learn and use more useful freewares for designing the better multimedia Chinese class by this paper.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.3
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• pp.347-354
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• 2014

The color appearance of a yarn-dyed woven fabric depends on the color of the yarn as well as on the weave structure. Predicting the final color appearance or formulating the recipe is a difficult task, considering the interference of colored yarns and structure variations. In a modern fabric design process, the intended color appearance is attained through a digital color methodology based on numerous color data and color mixing recipes (i.e., color prediction models, accumulated in CAD systems). For successful color reproduction, accurate color prediction models should be devised and equipped for the systems. In this study, the final colors of yarn-dyed woven fabrics were predicted using six geometric-color mixing models (i.e., simple K/S model, log K/S model, D-G model, S-N model, modified S-N model, and W-O model). The color differences between the measured and the predicted colors were calculated to evaluate the accuracy of various color models used for different weave structures. The log K/S model, D-G model, and W-O model were found to be more accurate in color prediction of the woven fabrics used. Among these three models, the W-O model was found to be the best one as it gave the least color difference between the measured and the predicted colors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2551-2557
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• 2012

This study analyses the relative importance of R&D business model of the small and medium manufacturing firm. We also compare samples by classifying by its properties, technology and market circumstance. The most important factor of the R&D business model is marketing factor and infrastructure factor is relatively less important. Also the relative importance of the R&D business model is different according to firm's properties and technology. So when government establishes the R&D policy, he focuses on designing the R&D business model.

• Macromolecular Research
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• v.17 no.10
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• pp.797-806
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• 2009

The mechanical and thermal behaviors of polyamide-6/clay nanocomposites were studied using the continuum-based, micromechanical models such as Mori-Tanaka, Halpin-Tsai and shear lag. Mechanic-based model prediction provides a better understanding regarding the dependence of the nanocomposites' reinforcement efficiency on conventional filler structural parameters such as filler aspect ratio ($\alpha$), filler orientation (S), filler weight fraction (${\Psi}_f$), and filler/matrix stiffness ratio ($E_f/E_m$). For an intercalated and exfoliated nanocomposite, an effective, filler-based, micromechanical model that includes effective filler structural parameters, the number of platelets per stack (n) and the silicate inter-layer spacing ($d_{001}$), is proposed to describe the mesoscopic intercalated filler and the nanoscopic exfoliated filler. The proposed model nicely captures the experimental modulus behaviors for both intercalated and exfoliated nanocomposites. In addition, the model prediction of the heat distortion temperature is examined for nanocomposites with different filler aspect ratio. The predicted heat distortion temperature appears to be reasonable compared to the heat distortion temperature obtained by experimental tests. Based on both the experimental results and model prediction, the reinforcement efficiency and heat resistance of the polyamide-6/clay nanocomposites definitely depend on both conventional (${\alpha},\;S,\;{\Psi}_f,\;E_f/E_m$) and effective (n, $d_{001}$) filler structural parameters.