• Geomechanics and Engineering
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• v.6 no.4
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• pp.391-401
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• 2014

In an attempt to make a numerical modeling of the nailed walls with a view to assess the stability has been used. A convenient modeling which can provide answers to nearly situ conditions is of particular significance and can significantly reduce operating costs and avoid the risks arising from inefficient design. In the present study, a nailing system with a excavation depth of 8 meters has been modeled and observed by using the three constitutive behavioral methods; Mohr Coulomb (MC), hardening soil (HS) and hardening soil model with Small-Strain stiffness ensued from small strains (HSS). There is a little difference between factor of safety and the forces predicted by the three models. As extremely small lateral deformations exert effect on stability and the overall deformation of a system, the application of advanced soil model is essential. Likewise, behavioral models such as HS and HSS realize lower amounts of the heave of excavation bed and lateral deformation than MC model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3018-3040
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• 2018

The mobility model is one of the most important factors that impacts the evaluation of any transportation vehicular networking protocols via simulations. However, to obtain a realistic mobility model in the dynamic urban environment is a very challenging task. Several studies extract mobility models from large-scale real data sets (mostly taxi GPS data) in recent years, but they do not consider the statuses of taxi, which is an important factor affected taxi's mobility. In this paper, we discover three simple observations related to the taxi statuses via mining of real taxi trajectories: (1) the behavior of taxi will be influenced by the statuses, (2) the macroscopic movement is related with different geographic features in corresponding status, and (3) the taxi load/drop events are varied with time period. Based on these three observations, a novel taxi mobility model (T-START) is proposed with respect to taxi statuses, geographic region and time period. The simulation results illustrate that proposed mobility model has a good approximation with reality in trajectory samples and distribution of nodes in four typical time periods.

• Journal of Energy Engineering
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• v.12 no.2
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• pp.101-108
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• 2003

The purpose of this study is to develop an entrainment model of the Pressurized Water Reactor (PWR) U-tube Steam Generator (SG) for Main Steam Line Break (MSLB) analyses. Generally, the temperature of the inside containment vessel at MSLB is decreased by introducing the liquid entrainment effect. This effect makes a profit on the aspect of integrity evaluation for Equipment Environmental Qualification (EEQ) in the containment. However, the target plant, Kori unit 1 does not have the entrainment data. Therefore, this study has been performed. RETRAN-3D and LOFTRAN computer programs are used for the model development. There are several parameters that are used for the initial benchmark, such as Combustion Engineerings (CE) experimental data and the RETRAN-3D model which describes the test leg. A sensitivity study is then performed with this model in which the model parameters are varied until the calculated results provide reasonable agreement with the measured results for the entire test set. Finally, a multiplication factor has been obtained from the 95/95 values of the calculated (best-estimate) quality data relative to the measured quality data. With this new methodology, an additional temperature margin of about 40$^{\circ}C$ can be obtained. So, the new methodology is found to have an explicit advantage to EQ analyses.

• Child Health Nursing Research
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• v.13 no.2
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• pp.201-211
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• 2007

Purpose: This study was designed to construct a structural model to explain the quality of life of grandmothers caring for their grandchildren. Method: Data were collected by self-report questionnaires from 232 grandmothers caring for their grandchildren living in Busan. The data collection period was from June to Oct. 2006. Data analysis was done with SAS 9.13 for descriptive statistics and PC-LISREL 8.52 program for Covariance Structural analysis. Results: The findings found that the fit of the hypothetical model to the data was good, but considering theoretical implications and statistical significances of parameter estimates, paths and variables of the model were modified by excluding 2 paths. The Modified Model with 17 paths showed a good fitness to the empirical data ($X^2=15.492$ (df=11, p=.161), GFI=.985 AGFI=.940 NFI=.982 RMSR=.037 RMSEA=.042). Health status, health problems, economical status, life events, caring stress, caring efficacy and life satisfaction had significant effects on quality of life in the grandmother caring their grandchildren, but of these variables, self-esteem was the most essential factor. All predictive variables of quality of life together explained 63.9% of the variance. Conclusion: The derived model in this study was confirmed to be proper in explaining and predicting the quality of life of the grandmothers caring their grandchildren.

• Women's Health Nursing
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• v.17 no.4
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• pp.328-336
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• 2011

Purpose: The purpose of this study is to develop the optimal nursing fee for nurse-midwifery center (MC) in the national health insurance system. Methods: The three methodologies used to calculate the conversion factors for the MCs in the national health insurance include cost accounting method, sustainable growth rate (SGR) model, and index model. In this study, the macro-economic indicators and the national statistics were used to estimate the conversion factors for the MCs. Results: The optimal nursing fee for the MCs in 2011 was estimated to be an increase of 57.7% by cost accounting analysis, a decrease of 17.1% by SGR model, and a decrease of 16.1% by index model. The results from SGR model and index model could had been biased due to the upswing of medical spendings in the short-term period (2008~2009). A sensitivity analysis of pre-delivery subsidy program for OB & GYN hospitals and clinics showed that the program has substantially diminished the demand for the MC services. Conclusion: More reliable methodologies to estimate nursing fees precisely are required to prove the value of nurses' services and a government subsidy program for the MC services should be followed from a social perspective.

• Wind and Structures
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• v.31 no.4
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• pp.321-334
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• 2020

Engineering type tropical cyclone (TC) wind field models are used to estimate TC wind hazard. Some of the models are well-calibrated using observation data, while others are not extensively compared and verified. They are all proxies to the real TC wind fields. The computational effort for their use differs. In the present study, a comparison of the predicted wind fields is presented by considering three commonly used models: the gradient wind field model, slab-resolving model, and a linear height-resolving model. These models essentially predict the horizontal wind speed at a different height. The gradient wind field model and linear height-resolving model are simple to use while the nonlinear slab-resolving model is more compute-intensive. A set of factors is estimated and recommended such that the estimated TC wind hazard by using these models becomes more consistent. The use of the models, including the developed set of factors, for estimating TC wind hazard over-water and over-land is presented by considering the historical tracks for a few sites. It is shown that the annual maximum TC wind speed can be adequately modelled by the generalized extreme value distribution.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.432-438
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• 2014

BACKGROUND/OBJECTIVES: This research was conducted to develop a construct model regarding the dietary style, late night snacking choice attributes and health promotion behaviors of industrial workers. SUBJECTS/METHODS: The surveys were collected during the period between January and February 2013. A statistical analysis of 888 industrial workers was conducted using SPSS 12.0 for Windows and SEM (Structural Equation Model) using AMOS (Analysis of Moment Structure) 5.0 statistics package. RESULTS: The results of the correlations between all variables showed significant positive correlations (P < 0.05). Results of factors analysis on dietary styles were categorized into five factors and health promotion behaviors were categorized into four. The reliability of these findings was supported by a Cronbach's alpha coefficient of 0.6 and higher for all other factors. After obtaining the factors from processing an exploratory factor analysis and the end results supported the validity. In an attempt to study the late night snacking choice attributes in accordance to dietary styles and the health promotion behaviors of industrial workers, a structural equation model was constructed and analyzed. CONCLUSIONS: All tests proved the model satisfied the recommended levels of the goodness on fit index, and thus, the overall research model was proved to be appropriate.

• Journal of Information Technology Services
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• v.11 no.sup
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• pp.51-60
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• 2012

In this paper, we provide the analysis of device model and method between device models for compatible M&S V&V of the NetSPIN. First of all, we analysis features, structure, and classification of the NetSPIN. The second, as a part of reliable V&V process, we analysis network system modeling process, correlation between device modeling process for M&S of the NetSPIN. The third, we suggest making a kind of pool of reference model and module of devices for the increase factor of reuse between device model. We also, at the point view of M&S V&V, conclude that there is the validity of the fidelity in device modeling process. Through the analysis of the NetSPIN device model and suggestion of the method for higher compatibility between device modes, the development process of device model be clearly understood. Also we present the effective method of the development for reliable device mode as the point of V&V.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.355-369
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• 2013

Purpose: This study is about Lean-NPD (New Product Development). Lean-NPD is Pulip Line's New Product Development type. This study introduced Lean-NPD Definition, Case Study, and Research Model of Lean-NPD. Empirical results of this survey will be provide suggestions to workers. Methods: Researcher developed research model about Lean-NPD activities. And researched Lean-NPD. This study analyzed model fitness and path significant with SEM(Structural Equation Model). Results: Fitness of the research model was satisfactory level. Leadership capabilities and production operations were significantly influence marketing capabilities(t> ${\pm}1.96$). Organizational culture significantly affected marketing capabilities(t> ${\pm}1.96$). R&D capabilities and marketing competencies had significant influence on business performance(t> ${\pm}1.96$). Marketing capabilities had significant influence on quantitative management performance(t> ${\pm}1.96$). Outstanding leadership appear to directly affect Qualitative Performance(t> ${\pm}1.96$). Conclusion: Under the excellent leadership and management environment definite organic Lean-NPD organizational culture significantly affects the operation can be seen. Lean-NPD of operational activities to provide value to customers, customer-oriented marketing activities can be seen that more important than anything. Lean NPD based on customer needs is key factor of growth.

• The Korean Journal of Applied Statistics
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• v.29 no.1
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• pp.75-83
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• 2016

We propose methodology to analyze the dynamic mechanisms of financial market contagion under market integration using a biological contagion analytical approach. We employ U-statistic to measure market integration, and a dynamic model based on an error correction mechanism (single equation error correction model) and latent factor model to examine market contagion. We also use quantile regression and Wald-Wolfowitz runs test to test market contagion. This methodology is designed to effectively handle heteroscedasticity and correlated errors. Our simulation results show that the single equation error correction model fits well with the linear regression model with a stationary predictor and correlated errors.