• Journal of the Korean earth science society
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• v.24 no.1
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• pp.7-21
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• 2003

The state-of-art third generation wave prediction model WAM was applied to the Korean seas for a winter monsoon period of January 1997. The wind field used in the present study is the global NSCAT-ERS/NCEP blended winds, which was further interpolated using a bi-cubic spline interpolator to fine grid limited area shallow water regime surrounding the Korean seas. To evaluate and investigate the accuracy of WAM, the hindcasted wave heights are compared with observed data from two shallow water buoys off Chil-Bal and Duk-Juk. A detailed study has been carried with the various meteorological parameters in observed buoy data and its inter-dependency on model computed wave fields was also investigated. The RMS error between the observation and model computed wave heights results to 0.489 for Chil-Bal and 0.417 for Duk-Juk. A similar comparison between the observation and interpolated winds off Duk-Juk show RMS error of 2.28 which suggest a good estimate for wave modelling studies.

• Journal of Korean Library and Information Science Society
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• v.44 no.2
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• pp.27-50
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• 2013

In this study, a smart Learning instruction model for school library was developed in terms of library instruction. Based on ADDIE model and ASSURE model, this model is organized considering the characteristics of school library, including facilities, materials, human resources, information problem solving process, collaborative teaching and blended learning, and utilizing smart devices. The entire procedure of this model is as follows: "establishment of instructional objectives${\rightarrow}$learner analysis${\rightarrow}$analyzing the learning environment${\rightarrow}$analyzing the learning task${\rightarrow}$instructional process design${\rightarrow}$developing instructional tool${\rightarrow}$instruction${\rightarrow}$evaluation". In addition, an instructional practice is provided for actual experience of smart Learning in school libraries.

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.115-121
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• 2012

Existing but largely unused binary star model capabilities are examined. An easily implemented scheme is parameterization of starspot growth and decay that can stimulate work on outer convection zones and their dynamos. Improved precision in spot computation now enhances analysis of very precise data. An existing computational model for blended spectral line profiles is accurate for binary system effects but needs to include damping, thermal Doppler, and other intrinsic broadening effects. Binary star ephemerides had been found exclusively from eclipse timings until recently, but now come also from whole light and radial velocity curves. A logical further development will be to expand these whole curve solutions to include eclipse timings. An attenuation model for circumstellar clouds, with several absorption and scattering mechanisms, has been applied only once, perhaps because the model clouds have fixed locations. However the clouds could be made to move dynamically and be combined into moving streams and disks. An area of potential interest is polarization curve analysis, where incentive for modeling could follow from publication of observed polarization curves. Other recent advances include direct single step solutions for temperatures of both stars of an eclipsing binary and third body kinematics from combined light and velocity curves.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.75-76
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• 2014

The present study has numerically investigated the effects of the oxidizer-side nitrogen dilution on the precise structure and NOx formation characteristics of the turbulent syngas nonpremixed flames. Eulerian particle flamelet model was used to predicted the NOx formation characteristics in the turbulent syngas swirling nonpremixed flames. Current numerical simulation was conducted for the syngas gas turbine combustor. Numericla results indicate that as the H2O portion is increased in diluent, the formation of NOx decreased effectively in turbulent syngas swirl nonpremixed flames.

• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.149-167
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• 2005

The minimum disparity estimators introduced by Lindsay and Basu (1994) are studied empirically. An extensive simulation in this paper provides a location estimate of the small sample and supplies empirical evidence of the estimator performance for the univariate contaminated normal model. Empirical results show that the minimum generalized negative exponential disparity estimator (MGNEDE) obtains high efficiency for small sample sizes and dominates the maximum likelihood estimator (MLE) and the minimum blended weight Hellinger distance estimator (MBWHDE) with respect to efficiency at the contaminated model.

• The Journal of Information Systems
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• v.17 no.4
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• pp.233-260
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• 2008

Universities have recognized e-Learning Systems as the critical IT resources which contribute to improving the competitiveness of the universities as well as the quality of the traditional class-based lectures. Instructors deliver the main contents in the class. Other supplementary activities like online discussions, sharing of teaching-learning materials, submission of homeworks, communication among the learners and between the instructors and the learners, and so on can be efficiently facilitated using e-Learning Systems. In other words, e-Learning Systems enable a blended learning combined class-based lectures and e-learning in a variety of ways. Nonetheless, compared to the level of implementation of e-Learning Systems, the usage of both the instructors and the learners is not high. Accordingly, this study examines the determinants to affect on the usage of e-Learning Systems from the learners perspective. To draw the key determinants, we review the IS literatures related to adoption or use of the IS like Media Richness Theory (MRT), Technology Acceptance Model (TAM), Social Influence Model (SIM), and Self-efficacy Model. The variables are drawn out to be expected on the usage of e-Learning like Media Richness, Ease of Use from MRT, TAM and Instructor's Influence, Co-learner's Influence from SIM, and Self-efficacy. To test our model and hypotheses, we have collected data in the class-based lectures using e-Learning System complementary. The results of the test with 192 data are as follows: Firstly, it shows that the Instructor's Influence and the Media Richness are the influential determinants to affect on the Perception of Usefulness of e-Learning Systems. Additionally, the Co-learner's Influence and Ease of Use in order is significant to the Perception of Usefulness. Secondly, as to the degree of use of the e-Learning Systems, the Co-leaner's Influence, the Media Richness, and the Ease of Use are, in that order, the significant determinants. The Perception of Usefulness, also, founded a key factor on increasing the use of e-Learning Systems. On the other hand, the Instructor's Influence is not significant to the use of e-Learning Systems. Finally, it has been found that Self-efficacy is significant to the Perception of Media Richness, Ease of Use, but not significant to the Perception of Usefulness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2305-2310
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• 2011

Recently, communication industry based on data and voice and broadcasting industry centering around images have been rapidly blended. Thereupon, this article aims to suggest a multi-approach method which minimizes the use of network bandwidth allowing multimedia streaming transmission to secure IP-based continuity and let users get multimedia services of one channel or several simultaneously. Also, this study intends to design a buffering strategy that can absorb network delay and an object model to assign and maintain stable channel bandwidth.

• Korean Journal of Computational Design and Engineering
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• v.12 no.3
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• pp.220-232
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• 2007

Current geometric modeling and analysis are commonly based on B-Rep modeling and a finite elements method respectively. Furthermore, it is difficult to represent an object whose material property is heterogeneous using the B-Rep method because the B-Rep is basically used for homogeneous models. In addition, meshes are required to analyze a property of a model when the finite elements method is applied. However, the process of generating meshes from B-Rep is cumbersome and sometimes difficult especially when the model is deformed as time goes by because the topology of deforming meshes are changed. To overcome those problems in modeling and analysis including homogeneous and heterogeneous materials, we suggest a unified modeling and analysis method based on implicit representation of the model using R-function which is suggested by Rvachev. For implicit modeling of an object a distance field is approximated and blended for a complex object. Using the implicit function mesh-free analysis is possible where meshes are not necessary. Generally mesh-free analysis requires heavy computational cost compared to a finite elements method. To improve the computing time of function evaluation, we utilize GPU programming. Finally, we give an example of a simple pipe design problem and show modeling and analysis process using our unified modeling and analysis method.

• Journal of Industrial Technology
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• v.41 no.1
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• pp.1-6
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• 2021

Fly ash and silica fume belong to industry by-products that can be used to produce concrete. This study shows the model of a neural network to evaluate the strength development of blended concrete containing fly ash and silica fume. The neural network model has four input parameters, such as fly ash replacement content, silica fume replacement content, water/binder ratio, and ages. Strength is the output variable of neural network. Based on the backpropagation algorithm, the values of elements in the hidden layer of neural network are determined. The number of neurons in the hidden layer is confirmed based on trial calculations. We find (1) neural network can give a reasonable evaluation of the strength development of composite concrete. Neural network can reflect the improvement of strength due to silica fume additions and can consider the reductions of strength as water/binder increases. (2) When the number of neurons in the hidden layer is five, the prediction results show more accuracy than four neurons in the hidden layer. Moreover, five neurons in the hidden layer can reproduce the strength crossover between fly ash concrete and plain concrete. Summarily, the neural network-based model is valuable for design sustainable composite concrete containing silica fume and fly ash.

• The Journal of Industrial Distribution & Business
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• v.9 no.2
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• pp.65-72
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• 2018

Purpose - One of the biggest problems in the e-learning distribution process is the lack of quality content and learners' discredit in e-learning content. In order to respond to the various demands of the corporate education field appropriately, it is necessary to search for directions of new e-learning models that are out of traditional e-learning contents. The purpose of this study is to identify recent trend issues related to corporate e-learning and to suggest directions for development. Research design, data, and methodology - Based on the literature review, trend issues that should be considered important in corporate e-learning were derived. Online survey was conducted to evaluate the importance-feasibility of each issue to 13 experts on e-learning and corporate education. The contents of the questionnaire are as follows: 1) recognition of importance and feasibility of trend issues to be considered important in the future corporate education field; 2) factors to be considered in developing future e-learning contents. Results - Six trends derived from a comprehensive literature review. The most important e-learning trends for corporate education field were 'mobile learning', 'micro learning', 'blended learning', 'social learning', 'adaptive learning', 'engaged learning'. As a result of evaluating the importance and feasibility of each issue, experts point out that 'mobile learning' and 'micro learning' should be actively considered for introduction and utilization at present. In addition, 'social learning' and 'blended learning' need to be actively considered in the near future. On the other hand, experts recognized that 'adaptive learning' and 'engaged learning' need to be prepared from a long-term perspective. Conclusions - There are two main reasons for this result. First, in corporate e-learning, it is important to 1) be able to update on time, 2) the connection with the workplace is important. Second, it requires realistic verification of the expected performance of the learning model. To be considered part of the future are as follows: First, the value and effectiveness of the new e-learning type should be studied. Seconds, e-learning contents should be developed through adopting SAM or Agile methodology. Through this process, we would be able to enhance the quality in e-learning content.