• Communications for Statistical Applications and Methods
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• v.16 no.3
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• pp.479-485
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• 2009

When a part of data is unobserved the marginal likelihood of parameters given the observed data often involves analytically intractable high dimensional integral and hence it is hard to find the maximum likelihood estimate of the parameters. Simulated maximum likelihood(SML) method which estimates the marginal likelihood via Monte Carlo importance sampling and optimize the estimated marginal likelihood has been used in many applications. A key issue in SML is to find a good proposal density from which Monte Carlo samples are generated. The optimal proposal density is the conditional density of the unobserved data given the parameters and the observed data, and attempts have been given to find a good approximation to the optimal proposal density. Algorithms which adaptively improve the proposal density have been widely used due to its simplicity and efficiency. In this paper, we describe a fully adaptive algorithm which has been used by some practitioners but has not been well recognized in statistical literature, and evaluate its estimation performance and robustness via a simulation study. The simulation study shows a great improvement in the order of magnitudes in the mean squared error, compared to non-adaptive or partially adaptive SML methods. Also, it is shown that the fully adaptive SML is robust in a sense that it is insensitive to the starting points in the optimization routine.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.366-369
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• 2004

Construction demands will become high. Defects liability is treating with a consumer on a defect. Maintenance bond is overlooking excessive responsibility of construction industry participants. This study classified the problem that are divided to systematic and internal matter. And this study presented an improvement proposal. An improvement proposal of a process may reduce a financial burden of contractors and sub-contractors. And improved rate decision will do additional consideration of the study result, so that it is appropriated a rate rationally.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.173-180
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• 2008

The major objective of this study is to proposal of measuring method and design for the testing curved railway in which the tilting train runs. In order to the speed-up of conventional lines that have many curve lines, there needs a improvement construction of substructure such as the straight or double track work and so on. But in this case, it needs to have a plenty of the cost and the period. Therefore, the tilting train which provides the high-speed service effectively in curve tracks was developed. Besides, the efficiency prediction and the linear synthesis of the existing conventional line for a tiling train service were examined on the preceding studies. So, in this paper we propose the measuring plan and the design of the improvement sections in the testing curved track which was decided as a results of material analysis and field research concerning the extension possibility of transition curves and the bearing of track due to the new developed train traveling. And we look forward to playing a decisive role as reference data on the improvement construction project for the commercial service of the tilting train.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.4
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• pp.70-79
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• 2018

This study would suggest a measure for the improvement of the commentary program on the building concentration area of Changdeokgung Palace. In the process of the survey, the researcher attended the commentary site and tape-recorded commentaries two times. The researcher conducted an analysis of the times and contents of the tape-recorded commentaries and evaluated their appropriateness, including historicity and connectivity to the site. In addition, the researcher figured out the commentaries and the visitors' movements through drawings and field surveys and analyzed the locations and conditions of the main facilities. Through a field survey and analysis, it was found out that the commentaries included the facts and anecdotes about the buildings, the related figures and history. However, it was found out that there were very insufficient commentaries on the buildings arranged according to the commentary movements, the outside space, in particular, the traditional landscape facilities. In addition, it was found out that there are areas that would need commentaries and opening for viewing. A proposal for the improvement of the commentary program was drawn up based on the analysis. New commentary points were added, and the commentaries of the outside space of the area and the traditional landscape facilities could improve through modifying the existing commentaries. With the proposal for improvement, the time required was calculated through reading aloud at a speed the same as the existing commentary speed. Through this, it was found out that the proposal for improvement could be implemented within one hour, the same as the present commentary program. This study has a significance that it provided a measure for practical improvement that could provide the visitors with quality commentary information and more interesting experience.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1997.10a
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• pp.37-40
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• 1997

This paper presents a performance improvement of distributed fuzzy control system by changing the triangular membership function widths according to the input variables. The control region consists of 4 parts according to the sign of error and change of error terms. Each control part is operated by the suitable nonuniform triangular membership function. Through the simulation for the boiler-turbin model of a fossil power plant using decentralized contol, it is verified this proposal

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.138-145
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.234.2-234.2
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• 2003

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1150-1153
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• 2005

The orders of Design-Build Delivery System (DBDS) in a large and public construction project have been increasing. Single Source Responsibility (SSR) for design and construction, which contributes to quality improvement of design and construction, has been performed. The DBDS performs SSR for design and construction, but, it has not maximized effect because of the dissatisfied alternative analysis procedures which are based on constructability evaluation and the information system in the design step. In this research, Constructability Evaluation Factors (CEFs) that must be evaluated, investigated, and reflected in the basic design step for design-build projects. The CEF proposed and the business process of each conductor has been systematized. To propose constructability evaluation factors, first classify drawing information by the constructability evaluation sphere. CEFs must be proposed to evaluate factors according to interference among work items. Second, applicable CEFs must be classified by preference ranking and weight. Third, the values of constructability factors in accordance with building elements and work items, need to be calculated. Finally, the CEFs proposal will support rational decision making, design cost reduction, and quality improvement through the values for constructability of building elements and work items.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.201-207
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• 2010

This paper covers a series of activities including initial proposal and actual development for the performance improvement of large-scale public facility management system under the application of green IT concept, which finally produced various excellent results in the administration of expense control, human resources, and general affairs. Actual development procedure starts from the analysis required by system users with the purpose of finding cost reduction opportunities under the application of green IT concept, which is followed by a series of activities including making a proposal for performance improvement, the development of trial system and the actual application into real system. As an example of large-scale public facility management system, national qualification management system was taken in order to convert the existing individual test storage unit into on-line storage space equipped with reinforced security function, resulting in acquisition of efficient productivity and greater savings in human resources as well as general expenses. A comparison with existing system and newly developed system was made in the area of number of operators, abnormal processing, system maintenances. It proved that efficiency increased to the minimum of 2 times and to the maximum 12 times with the 5 million savings of personal storage unit.

• Journal of Environmental Impact Assessment
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• v.7 no.1
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• pp.117-123
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• 1998

The present study was performed to improve the Environmental Impact Assessment system by comparing and analysing EIA systems for Residential Developments in the light of the business practice. For the improvement of EIA system, future strategies from each of three part ; the organ of approval(Construction&Transportation Dept.) for residential developments, the organ of consultation(Environment Dept.) for EIA and a developer(Korea Nation Housing Corp.), were analysed, and EIA systems and the processes of Residential developments were analysed. Results from the analysis of problems have provided a proposal for improvement of the Environmental Impact Assessment.