• Journal of the Korean Regional Science Association
• /
• v.31 no.3
• /
• pp.39-54
• /
• 2015

To assess an economic value of Cheonggyecheon river restoration project, an in-depth exit survey data was collected to apply travel cost method in this study. Poisson model, Negative Binomial, Zero-truncated Poisson, and Zero-truncated Negative Binomial model were executed due to the nature of count data. Empirical results showed that regressors were statistically significant and corresponded to general consumer theory. Since our survey data showed over-dispersion, Zero-truncated Negative Binomial was selected as an optimal one to analyze travel demand of Cheonggyecheon by model goodness of fit test among those aforementioned empirical models. Estimating an economic value of Cheonggyecheon river restoration project, which is known as an ecological river restoration project, we used annual visit of individual traveler and an optimal model. Suffice to say that the annual economic value of Cheonggyecheon river restoration project was estimated as 193.4 billion won in 2013.

• Journal of the Korea Convergence Society
• /
• v.6 no.4
• /
• pp.55-64
• /
• 2015

The purpose of this study is to analyze the relationship between the safety, working condition and the organizational commitment among crews members of airline companies in Korea. The data were collected from 230 employees of the a private airline company who gave their informed consent and completed a self-reported questionnaire in November, 2014. A structural equation model was established. The fitness of the hypothetical model was adequate (${\chi}^2=88.424$, df=48, RMR=0.044, GFI=0.940, CFI=0.964, NFI=0.926, IFI=0.965). Analysis of the hypothetical model demonstrated that effects of safety, working condition were significantly correlated with organizational justice and organizational commitment. The results of this study indicate that it is necessary to develop a safety program and working condition to encourage better organizational commitment of the pilot, leading to a brighter future for domestic airline business.

• Journal of Navigation and Port Research
• /
• v.28 no.6
• /
• pp.557-564
• /
• 2004

The WAM wave model has been widely used for wave hindcasting in the ocean by many domestic and foreign researchers due to its relative simplicity and high accuracy. As this model was originally developed for the condition of deepwater and comparatively coarse grid size covering wide area, it might produce in a fault result caused by the improper distribution of directional spreading. We extensively investigated involved problems based on WAM Cycle 4 model and suggested the improved WAM model so that it is applicable to both shallow water sea and fine mesh wave simulation The modified W AM model is verified here by comparing the computed result with and the observed data at Ieodo Ocean Research Station for September of 2003.

• Journal of Korea Water Resources Association
• /
• v.30 no.3
• /
• pp.279-291
• /
• 1997

This study is to evaluate the accuracy and practicality of the existing four conceptual models, two linear models of Clark and Nash model and two nonlinear models of Laruenson and WBN model, and to select an appropriate model to simulate the rainfall-runoff process in a given catchment. The variability of parameters for linear models is generally larger than that of nonlinear models. The errors in peak discharge are similar among the four conceptual models buy the errors in time to peak are quite different. Nonlinear models produce better results for time distribution than linear models. A comparison of the conceptual models to predict overall hydrograph using Friedman two-way analysis of variance by rank test indicates that nonlinear models are slightly better than linear models.

• Analytical Science and Technology
• /
• v.13 no.3
• /
• pp.304-308
• /
• 2000

The iodide was recovered from a simulated spent fuel to the sodium bisulfite aqueous solution. It was discussed that the trace iodide (below 1 ppm) was determined without the matrix effect of 0.1 M sodium bisulfite and 1 mM $HNO_3$ in aqueous solution by ion chromatography with UV detection. AS4A-SC (DIONEX) column and UV-absorption spectrophotometer were used. The UV-absorption spectra of sodium bisulfite, nitric acid and iodide were obtained, and then 230 nm was selected as an absorption wavelength for iodide determination. 0.1 M NaCl eluent was optimum condition. In this condition the calibration curve of iodide was obtained on the range of about 0-1,000 ppb. The linear coefficient was 0.99993 and the detection limit was 5 ppb. The relative standard deviation was 1.26%.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.5
• /
• pp.1354-1358
• /
• 2008

Environmental-friendly nontocxic flame retardant paint which can overcomes the restriction of harmful materials for human body and environments such as Pb, Hg, Cd, $C^{+6}$, PBB/PBDE by EU and domestic Ministry of Environment was developed. Developed paint is the water-soluble organic inorganic hybrid material that VOC(volatility organic compound) discharge is low, and that human riskiness and environmental pollution is minimized not using the kinds of halogen materials. $Mg(OH)_2$, $Sb_{2}O_{3}$, and Zinc borate were used as flame retardant materials, 2% Micell and water were used as binder and solvent, respectively. Results showed the optimum activity was obtained when the ratio of those frame retardant agents($Mg(OH)_2$, $Sb_{2}O_{3}$, Zinc borate made by 1: 2: 2), binder(2% Micell) and water was 1: 0.5: 0.5.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.319-322
• /
• 2018

Unplugged computing, the teaching and learning method, helps you learn the principles and concepts of computer science, and its advantage is that even elementary school students can easily understand it. Most of the North Korean Defector specialized alternative schools in the country have the purpose of having their students pass the qualification exam and be admitted to college. Therefore, the data, or information courses, are comprised of simple typing practices and basic office program handling. The purpose of the present study is to offer a teaching plan for these North Korean refugee adolescents, and we had assessed the courses in terms of its effectivity through a verification process. As a result, during the stage where we analyzed the answers from surveys, that they considered suggested curriculum for these specialized North Korean refugee alternative school was appropriate and have the potential to increase the student's satisfaction and interest.

• Journal of the Korea Convergence Society
• /
• v.8 no.5
• /
• pp.117-125
• /
• 2017

This is a convergence study to present strategies for performance enhancement by verifying the causal relationship between the influencing factor on the performance of the healthcare-associated infection control guidelines in hospital nurses. Participants were 388 nurses recruited from 16 different tertiary and general hospitals in Korea. Data collection was conducted using self-report questionnaires and analyzed using SPSS 21.0 and AMOS 21.0 programs. The overall fitness was ${\chi}^2=99.64$ (df=14, p<.01), GFI=.94, RMSEA=.10, NFI=.84, CFI=.90. The explanatory power of predictive variables on intention were 23.8%, and those on behavior were 17.7%. As a result of this study, it was found that TPB is an appropriate theory to explain the performance of healthcare-associated infection control guidelines, and repeated studies including multi-level modeling of career experience and organizational influences on behavior with strong social characteristics are needed.

• Journal of Korean Society of Forest Science
• /
• v.106 no.2
• /
• pp.213-218
• /
• 2017

The purpose of this study was to develop age-biomass model in Chungnam region containing random effect. To develop the biomass model by species and tree component, data for Pinus densiflora in central region is collected to 30 plots (150 trees). The mixed model were used to fixed effect in the age-biomass relation for Pinus densiflora, with random effect representing correlation of survey area were obtained. To verify the evaluation of the model for random effect, the akaike information criterion (abbreviated as, AIC) was used to calculate the variance-covariance matrix, and residual of repeated data. The estimated variance-covariance matrix, and residual were -1.0022, 0.6240, respectively. The model with random effect (AIC=377.2) has low AIC value, comparison with other study relating to random effects. It is for this reason that random effect associated with categorical data were used in the data fitting process, the model can be calibrated to fit the Chungnam region by obtaining measurements. Therefore, the results of this study could be useful method for developing biomass model using random effects by region.

• Environmental and Resource Economics Review
• /
• v.23 no.2
• /
• pp.331-347
• /
• 2014

The purpose of this study is to estimate the economic value of the recreational sea fishing in the Yellow Sea using count data model. For estimating consumer surplus, we used several count data model of travel cost recreation demand such as a poisson model(PM), a negative binomial model(NBM), a truncated poisson model(TPM), and a truncated negative binomial model(TNBM). Model results show that there is no exist the over-dispersion problem and a NBM was statistically more suitable than the other models. All parameters estimated are statistically significant and theoretically valid. The NBM was applied to estimate the travel demand and consumer surplus. The consumer surplus pre trip was estimated to be 254,453won, total consumer surplus per person and per year 1,536,896won.