• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.318-325
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• 2010

This study is to examine loyalty building model which reflected differentiated traits of professional service to establish strong loyalty for gaining competitive edge. Professional service is where consumer can not easily predict the result of service as well as other common traits. It also has trait that is difficult to evaluate service satisfaction and quality even after using the service because knowledge imbalance between service provider and user is great. Therefore, in professional service, satisfaction and emotion that consumer perceives in the service use process will play critical role in loyalty formation. As a result, the model of this study divided dimension into responsiveness satisfaction which is satisfaction dimension of professional service use process, interaction satisfaction, technical satisfaction and structurally examined the relationship between emotional commitment and cognitive commitment and the relationship between dimension of commitment and loyalty. The analysis result show that dimension of satisfaction which perceived in professional service use process increases both emotional commitment and cognitive commitment and these commitments effect to loyalty formation.

• Journal of Korea Water Resources Association
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• v.53 no.1
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• pp.1-13
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• 2020

The most common approach for computing engineering flow problems at high Reynolds number is still the Reynolds-averaged Navier-Stokes (RANS) computations based on turbulence models with wall functions. The recently developed generalized wall functions blending between the wall-limiting viscous and the outer logarithmic relations ensure a smooth transition of flow quantities across two regions. The performances and convergence properties of widely used turbulence models with wall functions that are applicable for turbulence kinetic energy (TKE), turbulent and specific dissipation rates, and eddy viscosity are presented through a series of near wall flow simulations. The present results show that RNG k-𝜖 model should be carefully applied with small tolerance to get the stable solution when the first grid lies in the buffer layer. The standard k-𝜖 and RNG k-𝜖 models are not sensitive to the selection of wall functions for both TKE and eddy viscosity, while the k-ω SST model should be applied together with kL-wall function for TKE and nutUB-wall functions for eddy viscosity to ensure accurate and stable boundary conditions. The applications to a backward-facing step flow at Re=155,000 reveal that the reattachment length is reasonably well predicted on appropriately refined mesh by all turbulence models, except the standard k-𝜖 model which about 13% underestimates the reattachment length regardless of the grid refinement.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.205-213
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• 2012

Transforming response variable is a general tool to adapt data to a linear regression model. However, it is well known that response transformations in linear regression are very sensitive to one or a few outliers. Many methods have been suggested to develop transformations that will not be influenced by potential outliers. Recently Cheng (2005) suggested to using a trimmed likelihood estimator based on the idea of the least trimmed squares estimator(LTS). However, the method requires presetting the number of outliers and needs many computations. A new method is proposed, that can solve the problems addressed and improve the robustness of the estimates. The method uses a stepwise procedure, suggested by Hadi and Simonoff (1993), to detect outliers that determine response transformations.

• Journal of Korea Water Resources Association
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• v.43 no.1
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• pp.1-13
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• 2010

For the first time, this study identifies Nash model parameters by GIUH theory based on grid of GIS with heterogeneity of drainage path. Identified parameters have advantages to improve accuracy and usefulness with considering hillslpoe-flow, geomorphological dispersion and easily extracting geomorphological factors by GIS in the watershed. Calculated results by identified parameters compare with observation data for verification of this model. The comparison is well correspondence between observed data and calculated results. And the comparison results of changing trends about lag time and the variance as hillslope and channel characteristic velocities sensitively present changes about hillslope characteristic velocity. Thus this model justifies that estimation of hillslope characteristic velocity demands with the great caution.

• The Korean Journal of Applied Statistics
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• v.7 no.2
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• pp.183-200
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• 1994

Data-adaptive sequential suboptimal designs for very complex computer simulation codes are considered based on a spatial prediction model. These designs are constructed for two simulators of the computational nuclear fusion devices model. The difficulty of constructing the optimal designs due to the irregular design region, and its alternatives are also discussed with some computational algorithms for obtaining the designs.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.186-191
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• 2017

The goal of this study was to develop an optimal formula for cookies containing soybean/seoritae, Hwanggum, and isomalto-oligosaccharide using response surface methodology to achieve a blood glucose lowering effect. The model showed a good fit with the experimental data [$R^2=0.92$ (soybean) and 0.93 (seoritae)]. However, the p-value of lack of fit was less than 0.05 and ridge analysis was used to determine an optimal formula. The estimated optimal conditions were as follows: soybean cookie: 68.7% soybean, 2.5% Hwanggum, and 75.2% isomalto-oligosaccharide; seoritae cookie: 56.5% soybean, 3.8% Hwanggum, and 56.2% isomalto-oligosaccharide. The area under the curve and glycemic index were significantly lower in the soybean cookie group than in the control. The glycemic load (GL) index of the soybean (19.9) cookie was in the range of a low-glycemic food (<20 GL). These results can be applied to develop a cookie with a blood glucose lowering effect.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.149-157
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• 2005

Typical water quality (WQ) parameters defined in the governing equation of the WQ model are the pollutant loads from atmosphere and watersheds, pollutant release rates from sediment, diffusion coefficient and reaction coefficient etc. The direct measurement of these parameters is very difficult as well as requires high cost. In this study, the pollutant budget equation including these parameters was used to construct the linear simultaneous equations. Based on these equations, the inverse problems were constructed and WQ parameter estimation method minimizing the sum of squared errors between the computed and observed amounts of the mass changes was suggested. WQ parameters, i.e., the atmospheric pollutant loads, sediment release rates, diffusion coefficients and reaction coefficient, were estimated using .this method by utilizing the vertical concentration profile data which has been observed in Cheonsu Bay and Ulsan Port. Values of the estimated parameters show a large temporal variation. However, this technique is persuasive in that the RHS (root mean square) error was less than $5.0\%$ of the observed value ranges and the agreement index was greater than 0.95.

• Journal of the Korean Geophysical Society
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• v.9 no.1
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• pp.27-36
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• 2006

The radiative convective equilibrium (RCE) temperature was calculated for the climate change study at King Sejong Station in West Antarctica. As a result of RCE model sensitivity test, the increases of surface albedo, solar zenith angle, and cloud optical thickness decrease surface temperature. On the other hand, the increases of carbon dioxide and cirrus cloud amount are caused by surface warming due to the greenhouse effect. According to the model calculation result, annual mean surface temperature shows a upward trend of 0.012oC/year during the period of 1958-2001. During the period of 1989∼2001, the trend of monthly mean surface temperature by model calculation is 0.01oC/month and the observation trend is 0.005oC/month.

• Geophysics and Geophysical Exploration
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• v.15 no.4
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• pp.219-226
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• 2012

This study provides an analysis on results of neutron logging for various borehole environments through numerical simulation based on a Monte Carlo N-Particle (MCNP) code developed and maintained by Los Alamos National Laboratory. MCNP is suitable for the simulation of neutron logging since the algorithm can simulate transport of nuclear particles in three-dimensional geometry. Rather than simulating a specific tool of a particular service company between many commercial neutron tools, we have constructed a generic thermal neutron tool characterizing commercial tools. This study makes calibration chart of the neutron logging tool for materials (e.g., limestone, sandstone and dolomite) with various porosities. Further, we provides correction charts for the generic neutron logging tool to analyze responses of the tool under various borehole conditions by considering brine-filled borehole fluid and void water, and presence of borehole fluid.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.857-870
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• 2010

This study was conducted to investigate the relationship between the socio-demographic factors and the Korean consumers palatability evaluation grades with Hanwoo sensory evaluation data from 2006 to 2008 by National Institute of Animal Science. The dichotomy logistic regression model and the multinomial logistic regression model are fitted with the independent variables such as the consumer living location, age, gender occupation, monthly income, beef cut and the the palatability grade as the categorical dependent variable and tenderness, 리avor and juiciness as the continuous dependent variable. Stepwise variable selection procedure is incorporated to find the final model and odds ratios are calculated to nd the associations between categories.