• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.6
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• pp.606-612
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• 1987

In this study, numerical model was developed to predict behavior of several layers in a solar pond and was solved by finite difference method. The empirical correlation that described heat and salt fluxes across interfacial boundary layer between mixed layer and diffusive layer in a solar pond were obtained from experiments and utilized in developing numerical model. As the results of this study, heat and salt fluxes across the interfacial boundary layer was found to depend on density ratio ${\beta}{\Delta}M_s/{\alpha}{\Delta}T.$ It was also found that the predicted value obtained by using the modified Weinberger's stability criteria showed a good agreement with experiment data.

• Journal of the Korean Geosynthetics Society
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• v.16 no.3
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• pp.31-39
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• 2017

Applicability of Skempton's and Hansbo's equation for estimating strength incremental ratio of Korean marine clayey soil was analyzed. These empirical equations have been commonly applied to design soft ground improvement by, especially, staged loading method. Strength incremental ratios proposed by Skempton (1954, 1957) and Hansbo (1957) using field vane tests(FVTs), measured in Scandinavia depends on plasticity index and liquid limit. Although lean clay in Scandinavia can be classified as clay based on USCS, this soil contains no clay mineral because it was produced by the glacial grinding of rock, sometimes, called rock flour. On the contrary, plasticity indices of Korean marine clayey soils increase linearly with the percentage of clay fraction (% finer than $2{\mu}m$ by weight). Except for strength incremental ratios using $q_u/2$ values in the case of soils having a low plasticity, such as Incheon, Hwaseong and Gunsan soils, these values are in the range of 0.25 to 0.35, independently of the plasticity index, $I_p$.

• The Journal of Information Systems
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• v.26 no.1
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• pp.21-51
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• 2017

Recently there have been an increasing number of companies suffering a negative brand image in the major media. Thompson et al. (2006) defined this as "$Doppelg{\ddot{a}}nger$ Brand Image." The images mentioned above have been created and propagated on Internet communities, which are one of the major paths of online spreading. This study will empirically analyze the effect of each $Doppelg{\ddot{a}}nger$ brand image on the customer's brand attitude, using a text-mining method focusing on "A company"'s case. This study will also cover the change in customer brand attitudes related to the company's correspondence in a situation in which the $Doppelg{\ddot{a}}nger$ brand image exists. In addition, the study will determine the presence of a priming effect after the spread of the $Doppelg{\ddot{a}}nger$ brand image. To that end, we collected 974 comments from 94,889 posts and A's official blogs related to A from B community, the largest automobile community site in Korea. Through this investigation, we obtained the following results. First, there was a significant difference in the ratio of negative sentiment of internet community before and after $Doppelg{\ddot{a}}nger$ brand image. Second, with regard to the topic modeling, the ratio of articles including negative topics increased and the other article ratio decreased over time. Finally, we found that there is a priming effect about negative brand image of "A company."

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.4
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• pp.282-289
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• 2001

This study analyzed the relationship between the physical properties of soil and the compression index of the soft clay in Gyungnam coastal region. Tests of physical and mechanical properties of soil have been carried out under the undisturbed condition at 82 Gimhae, 18 Jinhae and 27 Geojespecimens. The result showed that Terzaghi & Peck's empirical equation of the compression index were not applicable. The compression index of soft clay in Gyungnam coastal region was correlated with the water contents, the liquid limit and the initial void ratio. Among these, the initial void ratio showed the highest correlation with the compression index of soft clay in Gyungnam coastal region and the relationship is shown in the following. (1) The compression index of soft clay in Gyungnam coastal region is represented as follows: $C_c=0.74(e_o-0.7$ (2) The relationship between compression index and the swelling index in Gyungnam coastal region is represented as follows: $C_s=(1/8-1/15)C_c$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.118-122
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• 2006

For the development of a gas generator of a liquid rocket engine, the prediction of thermodynamic properties of combustion gas with respect to a propellant mixture ratio becomes critical. The present study focuses on the temperature measurement of exit combustion gas as a function of a mixture ratio through combustion tests of a fuel-rich gas generator propelled by Lox/Jet A-1. The measurement of combustion dynamic and static pressures allowed indirect estimation of thermodynamic properties like specific heat ratio, gas constant, and constant pressure specific heat. Comparing the results with empirical prediction through an interpolation reveals that the interpolation method calibrated using temperature results can be utilized as an effective tool for the design of a fuel-rich gas generator.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.179-190
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• 2008

Consumers earn a number of points for every purchase and then they can exchange a specified number of points for a desired reward in a typical loyalty program. The immediate payoff of their effort given as points is not the real reward they actually care about. It is merely an instrument (or medium) which has no value in itself. In a real world, consumers frequently choose the option with a bigger medium even though the economic value of the option is not changed by the medium. We call it 'medium effect'. In this study we explored if the size of medium affects on consumers' preferences. For this we controlled the reward options with three types of medium (small, medium, big) and measured the magnitude of preference difference among the three types of reward options. In addition, we manipulated comparability of reward options with wine and gas discount coupon. We confirmed that choosing one of two wines was easier than that of the two gas coupons. 164 respondents were allocated into three experimental groups and one control group. In three experimental groups, the ratios of the focused reward option's medium to the compared reward option's medium were different. For example, the focused reward option has 10 million points whereas the compared reward option has 10 million points for 1 million won purchase amount in the first group. Then each respondent was asked to choose one of two loyalty programs (focused program vs. compared program) in two different conditions (comparability between reward options: easiness vs. difficulty). To compare the medium effects among the experiment conditions we used chi-squares tests. The empirical results show the medium effect increases and then decreases as the ratio of reward mileages/points to purchase amount increases. Additionally, they let us know that comparability of alternatives affects on the medium effects depending on the ratio of reward mileages/points to purchase amount.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.462-471
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• 2008

The quality control for DCM is based on the unconfined compressive strength of laboratory treated soils, the cement contents, setting and checking the strength of in-situ treated soils. Also the strength of in-situ is checked mainly by the core boring. In case of large size construction, it might be considered the distribution of DCM strength data as normal distribution, so it might be employed a statistical method to evaluate DCM strength easily. In Japan, it has been established correlation between the strength of laboratory treated soils, the strength of in-suit treated soil and the design strength. Also It has been employed domestically the correlation suggested by Japan. But the correlation, so called $\lambda$(ratio in the strength of laboratory treated soils and the in-suit) and $\gamma$(ratio in the strength of in-suit and the design strength), might be far different with the domestic due to different DCM system and soil properties. so it might be restrictive to use domestically. Therefore in this paper, It is presented correlation between the strength of laboratory treated soils and in-suit treated soil to be employed domestically by evaluating $\lambda$ based on the domestic in-suit illustrations.

• Culinary science and hospitality research
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• v.23 no.2
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• pp.126-134
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• 2017

The purpose of this paper was to examine the dynamics of the price discovery function between lean hog futures and spot markets using the vector error correction model (VECM). The researcher also investigated the existence of the long-run equilibrium relationship between the lean hog futures and spot markets. Daily time series data of lean hog futures and spot observed in the Korean market during the period from 5 Jan. 2011 to 28 Dec. 2012 were analyzed. To examine the price discovery, this study employed the Gonzalo and Granger's (1995) information ratio and Hasbrock's (1995) information ratio measurement method. The significant findings of the study are summarized as follows. First, lean hog futures and spot market are significantly correlated. Secondly, the lean hog future market plays a more dominant role in price discovery than the spot market. Finally, price discovery measures based on the VECM suggested that the lean hog future market plays a more dominant role in price discovery than the lean hog spot market. This is the important systematic empirical work to find the relationship between the lean hog future and spot market.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.11
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• pp.1039-1048
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• 2008

new computational procedure for the Non-Linear Vortex Lattice Method (NLVLM) is suggested in this work. Conventional procedures suggested so far usually involves inner iteration loop to update free vortex shape and an under-relaxation based iteration loop to determine the free vortex shape. In this present work, we suggest a new formula based on quasi-steady concept to fix free vortex shape which eliminates the need for inner iteration loop. Further, the ensemble averaging of the induced velocities for a given free vortex segment evaluated at each iteration significantly improves the convergence property of the algorithm without resorting to the under-relaxation technique. Numerical experiments over several low aspect ratio wings are carried out to obtain optimal empirical parameters such as the length of the free vortex segment, the vortex core radius, and the rolled-up wake length.

• Management & Information Systems Review
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• v.33 no.3
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• pp.93-104
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• 2014

This study investigates price discovery between BlueNext spot and futures in EU ETS carbon emission markets using vector error correction model, GG and Hasbruck information ratio. Especially EUA is European Union Allowances traded on the Emissions Trading Scheme. This emission asset attracts and increasing attention among operators, investors and brokers on emission markets. In this study, we found BlueNext spot and EUA futures market are cointegrated. Following the preceding studies, we judged that EUA futures market contribute to the price discovery process than BlueNext spot market when this GG and Hasbrouck information ratio for BlueNext market are larger than 0.5. In other words, the futures market of EUA plays a more dominant role in price discovery than the spot market.