• Convergence Security Journal
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• v.8 no.4
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• pp.81-89
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• 2008

This paper introduces u-learning service model based on context awareness. Also, it concentrates on agent-based WPAN technology, OSGi based middleware design, and the application mechanism such as context manager/profile manager provided by agents/server. Especially, we'll introduce the meta structure and its management algorithm, which can be updated with learning experience dynamically. So, we can provide learner with personalized profile and dynamic context for seamless learning service. The OSGi middleware is applied to our meta structure as a conceptual infrastructure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.169-170
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• 2012

The efforts for improving 'Maritime Traffic Safety Assessment Scheme(MTSA scheme)' have continued to the present since May 27th, 2009. But recently, there's a controversy about whether it has been performed properly or the results is significant. These new discussions were arose from lack of validity and appropriateness we had yet to find. At this point, it needs to establish sound MTSA scheme through the comprehensive review. This research developed a suitable meta-evaluation model for MSTA with applying theory of the teta-evaluation, that is the evaluation of evaluations and verified by using meta-evaluation methods like as literature studies, expert reviews, surveys and etc. The results of this study can be used to evaluate MTSA activities and it will contribute to improving MTSA scheme.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1799-1810
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• 2011

Origin-Destination(OD) trip survey being used in travel demand forecasting has been obtained through totalizing process with direct sample survey techniques such as plate license survey, roadside interview, household travel survey, and cordon line counts. However, the OD survey has many discrepancies in sampling, totalizing process, and such discrepancies contains problems of difference between forecasted traffic volume and observed data. On the other hand, transit smart card data recently collected has credible resource of obtaining travel information for bus and metro. This paper presents parameter estimation of gravity model by using transit smart card data. Through the parameter estimation method, we estimated =0.57, ${\beta}$=0.14 of gravity model for bus, and ${\alpha}$=-0.21, ${\beta}$=0.05 for metro. The statistical test such as T-test, coefficient of correlation, Theil`s inequality coefficient showed no difference between observed volume and estimated volume. Elasticities of bus and metro derived in this paper are also reasonable.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.253-260
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• 2005

Recently, the storms which hit Korean Peninsula are getting bigger, and the damages from the storms are wide spreaded. Thus, and approach with disaster prebention to offshore area and/or opened island area is neccessary. The existing wave design parameter was calculated with linear regular wave models inputting deep water design wave or wind sources. so it wasn't able to deal with wind-induced waves, interactions with waves, and redistribution of wave energy simultaneously. In this study, we made numerical simulation with SWAN(Simulation Waves Nearshore) Model which can consider development of waves and winds and their interference. The result from this model shows much different with those from existing model's. so the result from this study, especially in this modeling area, could be used for harbor design and coastal disaster prevention field in the future.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.101-115
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• 2003

Lately there has been much theoretical and applied interest in linear models with non-normal heavy tailed error distributions. Starting Zellner(1976)'s study, many authors have explored the consequences of non-normality and heavy-tailed error distributions. We consider hierarchical models including selection models under a skewed heavy-tailed e..o. distribution proposed originally by Chen, Dey and Shao(1999) and Branco and Dey(2001) with Dirichlet process prior(Ferguson, 1973) in order to use a meta-analysis. A general calss of skewed elliptical distribution is reviewed and developed. Also, we consider the detail computational scheme under skew normal and skew t distribution using MCMC method. Finally, we introduce one example from Johnson(1993)'s real data and apply our proposed methodology.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.119-130
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• 2003

SP data have been widely used in assessing new transport policies and transport related plans. However, one of criticisms of using SP is that respondents may show different reaction between hypothetical experiments and real life. In order to overcome the problem, combination of SP and RP data has been suggested and the combined methods have been being developed. The purpose of this paper is to suggest a new SP and RP combined method using error component method and to verify the method. The error component method decomposes IID extreme value error into non-IID error component(s) and an IID error component. The method estimates both of component parameters and utility parameters in order to obtain relative variance of SP data and RP data. The artificial SP and RP data was created by using simulation and used for the analysis, and the estimation results of the error component method were compared with those of existing SP and RP combined methods. The results show that regardless of data size, the parameters of the error component method models are similar to those assumed parameters much more than those of the existing SP and RP combined models, indicating usefulness of the error component method. Also the values of time for error component method are more similar to those assumed values than those of the existing combined models. Therefore, we can conclude that the error component method is useful in combining SP and RP data and more efficient than the existing methods.

• Journal of the Korean Society for information Management
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• v.15 no.3
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• pp.95-112
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• 1998

This study is to investigate the problems in mapping between MARC data and Dublin core metadata, and to evaluate metadata as a source of cataloging. In addition resource description framework and its XML syntax for processing metadata in different format were analyzed in the view from encoding and transporting metadata in the network environments.

• Journal of the Korean Society for information Management
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• v.17 no.1
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• pp.21-47
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• 2000

Keeping the semantic interoperability between different formats is very important for reuseing and consistently processing metadata. This article is to design common schema and KORMARC schema based on RDF schema. For this, common elements are made by comparison of Dublin Core elements and KORMARC fields. The schema of these elements is designed for construction of semantic interoperability, basing RDF schema specification and syntax specification. Eventually, the semantic interoperability between a number of metadata formats can be constructed by matching the common elements to each attribute of format. KORMARC schema is designed by the application of common schema.

• Journal of the Korean Society for information Management
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• v.27 no.4
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• pp.169-191
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• 2010

This study aimed at developing preservation metadata elements and its applications for research information which is considered as a valuable digital resource these days. Specifically, the developed preservation metadata intends to provide a basis for the research information of the government-funded research institutes in economic and social science fields which are major knowledge producers of national policy. To ensure the interoperability of the research information across various departments and organizations, this study compared the elements from the CERIF(European Standard) and those from the PREMIS Data Dictionary which is based on OAIS reference model (ISO 14721). Based on this comparative analysis, this study developed complementary preservation metadata elements based on the two standards' characteristics. Consequently, this study suggested a new preservation metadata elements and its applications that are compatible between the two systems and can be implemented in practice.

• The Korean Journal of Applied Statistics
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• v.33 no.4
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• pp.439-449
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• 2020

Meta-analysis provides a way of integrating several independent studies of interest. Since small studies with statistically significant results are more likely to be published, publication bias, which is a special case of selection bias, often occurs in meta analysis. Conditional likelihood and weighted estimating equation have been proposed to deal with publication bias, but they require to specify a correct selection probability model. In contrast, the pairwise pseudolikelihood approach can correct publication bias without fully specifying the correct selection probability model, but its performance in meta-analysis was not investigated. In this paper, we perform a numerical study about whether the pairwise pseudolikelihood approach is effective for solving publication bias arising from typical meta-analysis settings.