• Geomechanics and Engineering
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• v.23 no.5
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• pp.455-466
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• 2020

This paper presents analysis of the interaction between tunnel and Qanat with a particular interest for the optimization of Qanat shape using the discrete element code, PFC2D, and the results will be compared with the FEM results of PLAXIS2D. For these concerns, using software PFC2D based on Discrete Element Method (DEM), a model with dimension of 100m ^⁎ 100 m was prepared. A circular tunnel with dimension of 9 m was situated 20 m below the ground surface. Also one Qanat was situated perpendicularly above the tunnel roof. Distance between Qanat center and ground surface was 8 m. Five different shapes for Qanat were selected i.e., square, semi-circular, vertical ellipse, circular and horizontal ellipse. Confining pressure of 5 MPa was applied to the model. The vertical displacement of balls situated in ground surface was picked up to measure the ground subsidence. Also two measuring circles were situated at the tunnel roof and at the Qanat roof to check the vertical displacements. The properties of the alluvial soil of Tehran city are: γ_dry=19 (KN/㎥), E= 750 (kg/㎠), ν=0.35, c=0.3(kg/㎠), φ=34°. In order to validate the DEM results, a comparison between the numerical results (obtained in this study) and analytical and field monitoring have been done. The PFC2D results are compared with the FEM results. The results shows that when Qanat has rectangular shape, the tensile stress concentration at the Qanat corners has maximum value while it has minimum value for vertical ellipse shape. The ground subsidence for Qanat rectangular shape has maximum value while it has minimum value for ellipse shape of Qanat. The vertical displacements at the tunnel roof for Qanat rectangular shape has maximum value while it has minimum value for ellipse shape of Qanat. Historical shape of Qante approved the finding of this research.

• Journal of Korea Technology Innovation Society
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• v.15 no.4
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• pp.837-861
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• 2012

In the knowledge society, the importance of sharing knowledge, technology, and information has been increasing. Due to the different characteristics of information itself, information marketing is a newly emerging perspective. This study aims to identify the factors which effect information customer value and satisfaction of the national R&D information service. The results show that information quality and service quality have a significant influence on customer value. In addition, the information quality, service quality and the information customer value have a significant positive effect on customer satisfaction. However, customer value of information acts as an intermediary between information quality and customer satisfaction. The indirect effects of information quality on the satisfaction are higher than the direct effect. On the other hand, the difference between the direct and indirect effect of service quality was not significant. After an analysis of research result, we discussed implications and limits of the study as well as future result direction.

• International Area Studies Review
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• v.14 no.3
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• pp.312-338
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• 2010

This paper investigates the value relevance of advertising activity over the period from 2001 to 2009 in the listed Korean stock markets(KOSPI and KOSDAQ). In addition, this paper divide all sample firm into several subsample, based on R&D intensity and export ratio in total sales. The empirical result of this paper shows following two evidence; First, advertising intensity, which proxies for advertising activity, is significantly related to firm value at the 1% level of significance. Second, advertising activity of high R&D intensity and high export ratio sample firms has more significant value relevance than for firms with low R&D intensity and low export ratio. The empirical results suggest that moderation effect of R&D intensity and export ratio are very important factor in determining the value relevance of advertising activity.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2010.11a
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• pp.203-212
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• 2010

Examining the relation between market structure and the value of innovation is important for competition and STI policy. If the value is large in a specific industry structure, government may lead the industry to take that form to enhance innovation. Our simple calibration in the case of linear demand and constant MC results in the conclusion that the incentive for R&D in the case of major and minor innovation in Cournot competition is less than that of merger and cooperative R&D. This emphasizes again "necessary evil" as a monopoly for innovation.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.430-438
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• 2012

This study researches the correlation between the firm value, which can be represented as Tobin's Q in this paper, and other financial information. The research is based on the financial statistics of KOSDAQ-listed Venture manufactures, which is comprised of the venture businesses group and the general group. The multiple regression, the correlation test tool, shows the R&D expenditures and tangible assets have the positive relation with the firm value while training expenses and the return on assets have the negative one. More specifically, R&D expenditures and total assets have the affirmative relations with the firm value among the venture businesses, whereas tangible assets, advertising expenses, and training expenses have the negative ones. The positive correlation between total assets and the firm value of venture business, shows that the volume of intangible assets impacts on the firm value of venture businesses. It also reflects the features of venture businesses highly relying on the technology development. The results are summarized as follows: First, The R&D expenditures and firm value have been positively correlated in the KOSDAQ-listed companies. Second, total assets and firm value has the positive correlation in the venture businesses.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.875-881
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• 1998

Microemulsion is prepared by the method of phase inversion emulsification with d-limonene that is environmental friendly substance and nontoxic to human body as dispersed phase. Emulsifier used for preparation of microemulsion is nonionic surfactants, polyoxyethylene nonylphenyl ether. Stability of prepared microemulsion was estimated by the various method of ξ-potential, hydrodynamic diameter and electric conductivity. When d-limonene is emulsified by NP series, microemulsion is most stable and narrowly distributed at HLB value of 12.3(either one emulsifier or mixed emulsifiers). Stability of microemulsion is increased as the amount of emulsifiers is increased at same HLB value of 12.3. In the case of using the same amount of emulsifiers, number of produced micelle are relatively large as hydrodynamic diameter is small. Therefore, the state of microemulsion is stable and the electric conductivity is increased. One can determine that higher electric conductivity value means that microemulsion has more micelles and is more stable.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.14-22
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• 2007

In this paper, the acoustic emission(AE) behaviors were investigated with single-and 2-spot resistance spot welded SPCC specimens. Test specimens were welded horizontally and/or vertically according to the rolling direction of base netal in 2-spot welding. In the case of 2-spot welding, when tensile-shear test has below amplitudes: crack initiation $50{\sim}60dB;$ tear fracture $40{\sim}50dB$. And when cross tensile test has below amplitudes: early stage $75{\sim}85dB;$ yielding point $65{\sim}75dB;$ post yielding $40{\sim}60dB;$ plug fracture $70{\sim}80dB\;or\;90{\sim}100dB$. Also, from the b-value that is slope of AE amplitude, we knew that there are lots of low amplitudes if b-value is big(i.e., tensile-shear $specimen{\rightarrow}tear$ fracture or shear fracture), and there are lots of high amplitudes if b-value is small(i.e.. cross tensile $specimen{\rightarrow}plug$ fracture). As the results of fiacture mechanism analyses through AE amplitude distributions, change of the b-value represented fracture patterns of materials. Correspondingly, low amplitude signals appeared in crack initiation, and high amplitude signals appeared in base metal fracture. We confirmed that these amplitude distributions represented the change or degradation of materials.

• STI Policy Review
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• v.2 no.3
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• pp.35-44
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• 2011

Korea has rapidly increased R&D investment over the last few decades and the intensity of R&D investment is among the highest in the world; however, there are serious concerns about R&D performance and R&D efficiency. This study is to improve the economic assessment methodology regarding a feasibility study for national R&D programs that are thought to be one of the most prominent ways to enhance R&D efficiency. In order to improve the methodology of economic assessment, a few of important factors such as technical or market uncertainty, spillover effect, and R&D contribution ratio should be covered in the model. The focus of this article is technological and market uncertainty that has a close relation with strategic flexibility and utilization potential to increase the value of R&D programs. To improve the current linear and definitive R&D process, a new framework with strategic flexibility is suggested, in which the result of economic assessment that considers technological and market uncertainty is reflected in planning. That kind of feedback process is expected to enhance the value of the program/project as well as R&D efficiency.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.1
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• pp.14-26
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• 2010

This study investigates the effectiveness of fashion coordination presentation formats when people buy apparel products online. This study conducted an online survey with 595 females who shopped online at the simulated website by a single apparel plan picture (n=189), coordination plane picture (n=187), and 3-D coordination image (n=216). For data analysis, factor analysis, Cronbach's alpha, MANCOVA, ANOVA, Duncan test, correlation analysis, and chi-square are used. The results of this study are: First, the hedonic shopping value was significantly the highest when respondents shopped at a 3-D coordination image shopping mall, the next highest-scored presentation type was the coordination plane picture, and the case of presenting only the single apparel picture was significantly the lowest. The utilitarian shopping value and information shopping value were higher in the coordination plane picture and the 3-D coordination image shopping mall than the single apparel picture. Second, transactions satisfaction was high when respondents shopped at a 3-D coordination image, coordination plane image, and single apparel image in decreasing order.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.356-362
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• 2000

Yakju(rice wine) was sterilized with high-voltage square-wave pulses of $1\;{\mu}s$ duration at various electric field strengths and frequencies on a serial multiple electrode pulsed electric field(PEF) treatment system consisted of 7 electrodes connected in series. The initial microbial counts of Yakju were $1.88{\times}10^3{\sim}2.13{\times}10^4$ CFU/mL for total aerobes, $1.55{\times}10^3{\sim}2.85{\times}10^4$ CFU/mL for lactic acid bacteria and $1.72{\times}10^3{\sim}2.39{\times}10^4$ CFU/mL for yeasts. The sterilization of microorganisms in Yakju was a first order reaction and the sterilization effect increased as the field strength and the frequency increased. The $D_{Hz}-value$ and the $D_{PEF}-value$ decreased with the electric field strength. Yeast showed lower $D_{PEF}-value$ than bacteria. Lactic acid bacteria showed lower $D_{PEF}-value$ than general aerobic bacteria under the electric field strength below 30 kV/cm, but higher ones under that above 40 kV/cm. The $Z_{PEF}-value$ of general aerobic bacteria, lactic acid bacteria and yeast in Yakju were 39.4, 49.3 and 47.6 kV/cm, respectively. The PEF sterilization resulted in less changes in color and sensory properties than heat sterilization, and the PEF treated Yakju showed superior quality to the heat treated one. The commercial sterilization of Yakju was accomplished with 2-cycle treatment on the tested serial PEF treatment system.