• Journal of Ocean Engineering and Technology
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• v.34 no.3
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• pp.167-179
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• 2020

Recently, the increasing importance of artificial intelligence (AI) technology has led to its increased use in various fields in the shipbuilding and marine industries. For example, typical scenarios for AI include production management, analyses of ships on a voyage, and motion prediction. Therefore, this study was conducted to predict a response amplitude operator (RAO) through AI technology. It used a neural network based on one of the types of AI methods. The data used in the neural network consisted of the properties of the vessel and RAO values, based on simulating the in-house code. The learning model consisted of an input layer, hidden layer, and output layer. The input layer comprised eight neurons, the hidden layer comprised the variables, and the output layer comprised 20 neurons. The RAO predicted with the neural network and an RAO created with the in-house code were compared. The accuracy was assessed and reviewed based on the root mean square error (RMSE), standard deviation (SD), random number change, correlation coefficient, and scatter plot. Finally, the optimal model was selected, and the conclusion was drawn. The ultimate goals of this study were to reduce the difficulty in the modeling work required to obtain the RAO, to reduce the difficulty in using commercial tools, and to enable an assessment of the stability of medium/small vessels in waves.

• Structural Engineering and Mechanics
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• v.49 no.1
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• pp.23-40
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• 2014

In this article, using finite element method of analysis (FEM), behavior of the endplate moment connection subjected to axial force and bending moment is investigated. In the FEM model, all the nonlinear characteristics such as material, geometry, as well as contact have been included. First, in order to verify the numerical model of the connection, an analysis of the endplate moment connection conducted without the application of the axial force. Results obtained from FEM indicating a close and good correlation with the experimental results. Then to investigate the influence of the axial forces, the connections subjected to axial forces as well as the bending moment are analyzed. To observe the overall effect of these actions, the momentaxial force interaction diagrams are drawn. It is observed that the presence of axial force even in a small value can change the behavior of the connection significantly. It is also shown that the axial forces can alter the failure mode of the connection; and therefore it could result in a different than the predicted moment capacity of the connection.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.719-723
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• 2007

It is very active that existing companies of providing e-Learning contents try to differentiate themselves through a business model based on Web 2.0. For instance, Etoos, online education website (www.etoos.com) run by SK Communications has made more space where students can participate in the Web 2.0 era and overhauled its website completely, turning into an open-ended one, which strengthens learning and fun in 2007. This study is to analyze the present state of e-Learning contents with representative e-learning sites for middle and high school students, to find that the development direction for next generation e-Learning lies in developing contents focusing on learners that can get effective feedback and drawing collective intelligence grounded on the essence of Web 2.0, and to suggest 'the project to form virtual private tutor community in e-Learning contents.'

• Journal of the Korean Society for information Management
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• v.24 no.4
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• pp.173-189
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• 2007

By measuring satisfaction index of the users of Information System, it is possible not only to estimate ROI(Return on Investment) but also to draw the device for the efficiency and improvement of the System. This study tries to give User Satisfaction Index Model for the System, and present operators and managers of the system with the method for improving satisfaction and efficiency by measuring the User Satisfaction Index of representative information systems. For this, the survey was carried out for the representative information systems. On the basis of the analysis, Satisfaction Index was drawn and through Matrix Analysis, the strategy for system improvement was derived.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1167-1176
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• 2009

Few studies have investigated the quantitative relationship between port ownership structure and port efficiency with mixed results. This paper therefore contributes to the empirical literature by investigating the impact of port privatization on port efficiency using sample data drawn from the world's major ports. Moreover, this study applies the Bayesian approach to estimate the impact of port ownership on port efficiency. We fit Bayesian stochastic frontier model which is introduced by Griffin and Steel (2007) by WinBUGS. World's 25 main ports data are used for analysis. Based on MCMC sampling, we estimate parameters of the model and efficiency index of each ports. Moreover, we add estimates from package Frontier 4.1c in order to compare them with Bayesian results.

• Journal of Magnetics
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• v.19 no.4
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• pp.315-322
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• 2014

In this work, Artificial Neural Network (ANN) was used to model the dynamic behavior of ferromagnetic hysteresis derived from performing the mean-field analysis on the Ising model. The effect of field parameters and system structure (via coordination number) on dynamic critical points was elucidated. The Ising magnetization equation was drawn from mean-field picture where the steady hysteresis loops were extracted, and series of the dynamic critical points for constructing dynamic phase-diagram were depicted. From the dynamic critical points, the field parameters and the coordination number were treated as inputs whereas the dynamic critical temperature was considered as the output of the ANN. The input-output datasets were divided into training, validating and testing datasets. The number of neurons in hidden layer was varied in structuring ANN network with highest accuracy. The network was then used to predict dynamic critical points of the untrained input. The predicted and the targeted outputs were found to match well over an extensive range even for systems with different structures and field parameters. This therefore confirms the ANN capabilities and indicates the ANN ability in modeling the ferromagnetic dynamic hysteresis behavior for establishing the dynamic-phase-diagram.

• Journal of Digital Contents Society
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• v.13 no.4
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• pp.625-629
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• 2012

This paper is presented to prepare NGN quality assurance management process under the quality system test methodology. The process should be drawn for NGN quality measurement framework of multimedia traffic. NGN test bed management process model are QoS measurement metrics, measurement interval meter above, and measuring tools, measuring equipment, measurement methods and measurement results from a series of processes for the analysis and methodology. This model, NGN quality assurance activities should be utilized in the future. Quality target level only when themselves constantly measured and managed, does not guarantee the communication quality of service. It is sensitive to the importance of NGN network technology paradigm for research on quality management in the NGN.

• Child Health Nursing Research
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• v.24 no.1
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• pp.37-47
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• 2018

Purpose: The purpose of this study was to construct a model to explain the parenting satisfaction associated with the role transition of older mothers with preschool children. Methods: The participants of this study were mothers of 3- to 6-year-old children who gave birth after 35 years of age, and were drawn from 16 child care centers and 8 kindergartens in 4 administrative districts of B city. Data were analyzed using SPSS for Windows version 22.0 and AMOS for Windows version 22.0. Results: Parental stress, mother-child interactions, parental beliefs regarding personality, and socioeconomic status (income, education, and occupation) had direct effects on parenting satisfaction. Social support also showed direct and indirect effects. Among the sub factors of child temperament, sociability had a significant effect. These variables explained 57.4% of the variation in parenting satisfaction. Conclusion: The results of this study will contribute to the development of effective programs to enhance the parenting satisfaction of older mothers, and will help older mothers through the role transition necessary for the growth of their children.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.21 no.2
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• pp.97-110
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• 2010

The purpose of this study was to develop a curriculum model for the professional development of children's librarians at the university level through literature reviews, theoretical studies, survey of children's librarians' needs for their professional development, and investigation of the conditions of operation in the course of library and information sciences. The curriculum consists of five areas: (1) children's librarian, (2) child, (3) materials, (4) service, and (5) library management. There are two tracks: one for refinement in 90 hours, and the other for professional development in 165 hours. Some courses are made up practical activities drawn from theoretical foundations. The courses blend on-line and off-line styles of learning.

• Journal of Information Technology Applications and Management
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• v.11 no.1
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• pp.1-14
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• 2004

Increasing affectability of high-speed Internet and convenient access devices has made the Internet a major source of information search and sharing. As the provision of information has rapidly becomes an important and viable business model, the objective utility and marketability of information contents have become a focus of interest among many academicians and managers. Researchers have traditionally focused on the design of the interface, availability of resources, network accessibility, the format of web sites and their underlying systems. However, the usefulness of contents has been left as a little explored issue. To correctly diagnose and pursue the viability of contents provision business a shift of perspective is required : a shift from technology-oriented perspective toward user-oriented perspective, and a shift from form and design focus toward content focus. This research attempted to analyze consumer-oriented information quality in a more systematic way by focusing on a limited domain travel-related information contents. We proposed a relationship among consumers'behavior, characteristics of information, and the values of information measured by users. An empirical examination of the model was performed using a survey on Internet users in Korea. Implications are drawn for managers responsible for creating marketable contents.