• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2000.09a
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• pp.176-181
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• 2000

This paper briefly outline the approach we are now setting for improving the existing global ocean tidal charts in next few years. There has been notable progress in predicting global ocean tide in mid 90s to improve correction procedures for tidal signals in altimetry with more accurate tidal models (http://podaac.jpl.nasa.gov/) than existing ones. (omitted)

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.141-147
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• 2006

BOK-X12-ARIMA has been developed by the Bank of Korea in order to accomodate special features such as lunar effect, labor day and election effect which are intrinsic in Korean seasonal time series. Irregular component resulting from BOK-X12-ARIMA is usually treated as white noise time series. If this shows dependency structure, it may be advisable to incorporate dependency in irregular component into prediction. This article illustrates how to refine point forecast using dependency structure in irregular component.

• Health Policy and Management
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• v.25 no.3
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• pp.185-196
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• 2015

Background: Issues concerning with the classification accuracy of Korean Outpatient Groups (KOPGs) have been raised by providers and researchers. The KOPG is an outpatient classification system used to measure casemix of outpatient visits and to adjust provider risk in charges by the Health Insurance Review & Assessment Service in managing insurance payments. The objective of this study were to refine KOPGs to improve the classification accuracy and to evaluate the refinement. Methods: We refined the rules used to classify visits with multiple procedures, newly defined chemotherapy drug groups, and modified the medical visit indicators through reviews of other classification systems, data analyses, and consultations with experts. We assessed the improvement by measuring % of variation in case charges reduced by KOPGs and the refined system, Enhanced KOPGs (EKOPGs). We used claims data submitted by providers to the HIRA during the year 2012 in both refinement and evaluation. Results: EKOPGs explicitly allowed additional payments for multiple procedures with exceptions of packaging of routine ancillary services and consolidation of related significant procedures, and discounts ranging from 30% to 70% were defined in additional payments. Thirteen chemotherapy drug KOPGs were added and medical visit indicators were streamlined to include codes for consultation fees for outpatient visits. The % of variance reduction achieved by EKOPGs was 48% for all patients whereas the figure was 40% for KOPGs, and the improvement was larger in data from tertiary and general hospitals than in data from clinics. Conclusion: A significant improvement in the performance of the KOPG was achieved by refining payments for visits with multiple procedures, defining groups for visits with chemotherapy, and revising medical visit indicators.

• Journal of Soil and Groundwater Environment
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• v.28 no.2
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• pp.12-29
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• 2023

Conceptual site model (CSM) development and enhancement for contaminated sites assists in identifying data gaps during the site investigation process. In this study, CSM was developed and enhanced for a contaminated site in Korea as a case study. Site Y was scrutinized four times previously. The site profiles for each scrutiny were reorganized based on the scrutiny reports, and the relevant data was utilized to develop and enhance CSMs. CSM for the first investigation was developed in various forms including table, flowchart, diagram, and narrative formats. CSM was enhanced in a stepwise manner by incorporating the updated profile information obtained in next investigation to existing CSM. The hypothetical data gap analysis between each investigation step was established to meet the purpose of the follow-up investigation. This case study showed that CSM is a useful tool to identify the history and current status of contaminated sites and thereby help in planning supplementary investigations for better site characterization.

• Journal of The Korean Association For Science Education
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• v.23 no.3
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• pp.276-285
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• 2003

In the earlier study, Park (2002) described the process of student' conceptual change as a successive refinement and articulation of their conceptual framework. In this study, the process of conceptual change for three university students were analyzed more in depth. As results, six types of conceptual change through successive refinement and articulation were observed: (1) original conception was elaborated in detail, (2) conception was differentiated according to the context, (3) some conceptions were re-explained theoretically after construction it based on experimental data, (4) non-coherent conceptions in the early stage get to have coherency in the later stage, (5) model of explanation gets to be complicated by excluding ideal conditions, (6) qualitative explanations were changed into quantitative ones.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.6
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• pp.621-629
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• 2008

Procedures involved in the refinement of the regional geoid for the area encompassing the Korean peninsula and the East Sea are described, and the computational results are provided. A comparison between the geoid height data, the mean sea surface height and the final product of the refinement work is provided and analyzed. The regional marine geoid thus refined seems to have a better resolution, in terms of its correlation with the bathymetry, and shows the bottom features in a more detailed manner when compared with previously used procedures. The general pattern of the computed geoid profile matches reasonably well with the existing studies, where the correlations between the refined regional marine geoid and the bathymetry are (1) 0.44 for the area $117{\sim}142.5^{\circ}E/24{\sim}52^{\circ}N$ and (2) 0.47 for the area $127{\sim}142.5^{\circ}E/32{\sim}50^{\circ}N$ in the East Sea respectively.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.258-267
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• 2013

New incremental learning algorithm using extended data expression, based on probabilistic compounding, is presented in this paper. Incremental learning algorithm generates an ensemble of weak classifiers and compounds these classifiers to a strong classifier, using a weighted majority voting, to improve classification performance. We introduce new probabilistic weighted majority voting founded on extended data expression. In this case class distribution of the output is used to compound classifiers. UChoo, a decision tree classifier for extended data expression, is used as a base classifier, as it allows obtaining extended output expression that defines class distribution of the output. Extended data expression and UChoo classifier are powerful techniques in classification and rule refinement problem. In this paper extended data expression is applied to obtain probabilistic results with probabilistic majority voting. To show performance advantages, new algorithm is compared with Learn++, an incremental ensemble-based algorithm.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.773-775
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• 2003

From the view point of data fusion, we integrate LIDAR data and digital aerial images to perform 3D building modeling in this study. The proposed scheme comprises two major parts: (1) building block extraction and (2) building model reconstruction. In the first step, height differences are analyzed to detect the above ground areas. Color analysis is then performed for the exclusion of tree areas. Potential building blocks are selected first followed by the refinement of building areas. In the second step, through edge detection and extracting the height information from LIDAR data, accurate 3D edges in object space is calculated. The accurate 3D edges are combined with the already developed SMS method for building modeling. LIDAR data acquired by Leica ALS 40 in Hsin-Chu Science-based Industrial Park of north Taiwan will be used in the test.

• Journal of the Mineralogical Society of Korea
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• v.9 no.1
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• pp.43-53
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• 1996

The detailed crystal chemistry of ilmenite from the Hadong massif was studied by the EPMA, M ssbauer spectroscopy, and Rietveld structural refinement using X-ray powder diffraction data. The ilmenite-bearing anorthosite shows complicated mineral assemblage which consists of plagioclase, clinopyroxene, hornblende, biotite, chlorite, apatite, allanite, and zircon. Anorthite is andesine in composition (Ab 28-57), and clinopyroxene drops in ferro-hypersthene (Fs 62-70). Ilmenite is trigonal symmetry with R space group, whose structure shows the alternation of Fe2+ (M1 site) octahedral layer and Ti (M2 site) layer along c axis. M ssbauer spectroscopy indicates that there are three doubles which assigned to couple of Fe2+($\delta$=0.812, 0.890mm/sec) and one Fe3+($\delta$=0.303mm/sec) in octahedral sites. Their Fe3+/$\Sigma$Fe is 0.065 and chemical formula is established as Fe2+0.94Fe3+0.07Ti0.97O3 using both EPMA and M ssbauer analysis. Rietveld structural refinement reveals that site occupancies of Fe in M1 and Ti in M2 are 91.2% and 89.4%, respectively. This implies that Ti and Fe2+ are alternatively occupy M1 and M2 sites. In addition, smaller M2 site is more preferable to Fe3+ occupancy over M1.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.288-295
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• 2003

An adaptive procedure in finite element analysis is presented by p-refinement of meshes in conjunction with a posteriori error estimator that is based on the recovery technique. In case of the recovery technique, the SPR(superconvergent patch recovery) approach has been modified for p-adaptive mesh refinement. The strategy of finding a nearly optimal distribution of polynomial degrees on a fixed finite element mesh is discussed such that a particular element has to be refined automatically to obtain an acceptable level of accuracy by increasing p-levels non-uniformly. To verify the proposed algorithm, the limit value approach is proposed which utilizes the exact strain energy computed from the extrapolation equation. A new pre-processor is developed for the p-version finite element program in which the vector graphic editor is used for the automatic generation of node connection and coordinate by halfedge solid data structure according to uniform or nonuniform p-distribution. The general 2-D algorithm is also developed to generate face modes and internal modes in accordance with different mesh types. The quality of the error estimator is investigated with the help of two mumerical examples. The results show that the sequences of p-distributions obtained by the proposed error indicator closely follow the optimal trajectory.