• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.223-229
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• 2011

The taxonomy of the Isodon excisus complex has been ambiguous and problematic because the morphological characters, especially characters related to the leaf distinguishing subgroups of the complex in the original descriptions, are variable. To elucidate the taxonomic structure of the I. excisus complex in Korea, 34 characters were measured from 70 OTUs representing different locations and analyzed by principal component analysis (PCA). The analysis showed that principle component axis 1, 2, 3 (PC1, PC2, PC3) represents 52.0% of the total variance and characters showing high loading values for PC1 were leaf shape, density of non-glandular hairs on the lower surface of the leaf, and characters related to the teeth of the leaf. The length of apical tooth and the angle between two widest points of the leaf were highly correlated to PC2 and PC3, respectively. Three-dimensional scatter plotting of OTUs for PC1, PC2, and PC3 axis showed that the areas of previously recognized three subgroups of I. excisus completely overlapped. Our result supported that just one taxon, I. excisus var. excisus, should be recognized in the complex at the variety level.

• Earthquakes and Structures
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• v.11 no.6
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• pp.1043-1060
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• 2016

The engineering background of this article is an ancient wooden building with extremely high historic and cultural values in Tibet. A full understanding of the dynamic behaviour of this historic building under in-service environments is the basis to assess the condition of the structure, especially its responses to earthquake, environmental and operational loading. A dynamic monitoring system has been installed in the building for over one year and the large amounts of high quality data have been obtained. The paper aims at studying the dynamic behaviour of the wooden building in seismic and operational conditions using the field monitoring data. Specifically the effects of earthquake and crowd loading on the structure's dynamic response are investigated. The monitoring data are decomposed into principal components using the Singular Spectrum Analysis (SSA) technique. The relationship between the average acceleration amplitude and frequencies of the principle components and operational conditions has been discussed. One main contribution is to understand the health condition of complex ancient building based on large databases collected on the field.

• Journal of Information Display
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• v.3 no.3
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• pp.1-11
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• 2002

Multi-view function is important to three-dimensional displays without dedicated glasses. It is the reason that the observers earnestly desire to change their positions freely. Multi-viewing is also principal to the reality of three-dimensional (3D) image displayed on the screen. The display of projection type has the advantage that the number of viewing points can be easily increased according to the number of projectors. The authors research on multi-view projection display with hologram screen. Powerful directionality of the diffracted beam from hologram screen is required unlike two-dimensional (2D) display. We developed a new method that all diffracted beams satisfied the same Bragg condition and became sufficiently bright to observe the 3D image under usual indoor light. The principle is based on the essential Bragg diffraction in the three-dimensional space. Owing to such three-dimensional Bragg diffraction we achieved an excellent hologram screen that could be multiple reconstructed in spite of single recording. This hologram screen is able to answer arbitrary numbers of viewing points within wide viewing zone. The distortion of 3D image becomes also sufficiently small with the method of dividing the cross angle between illumination and diffraction beam.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.11a
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• pp.21-27
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• 2001

Springs are widely utilized in machine element. To find out stiffness of frustum-shaped coil spring, the space beam theory using the finite element method is adopted in this paper In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. To find out load vector of coil spring subjected to distributed compression, principle of virtual work is adapted The displacements of nodal points due to small increment of force are calculated by the finite element method and the calculated nodal displacements are added to coordinates of nodal points. The new stiffness matrix of the system using the new coordinates of nodal points is adopted to calculate the another increments of nodal displacements, that is, the step by step method is used in this paper. The results of the finite element method are fairly well agreed with those of various experiments. Using MATLAB program developed in this paper, spring constants and stresses can be predicted by input of few factors.

• The Journal of Korean Medicine
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• v.32 no.5
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• pp.41-49
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• 2011

Objectives: To optimize the preservation method of herbal decoction, we investigated the content of principle components of Pyungwi-san, liquiritin, glycyrrhizin, and hesperidin according to preservation temperature and period. We also investigated the changing patterns of pH and microbial population in Pyungwi-san decoction as a model case. Methods: With samples preserved at different temperatures, the content of liquiritin, glycyrrhizin, and hesperidin was determined using HPLC and microbial population was determined as viable counting method up to 8 times every month. Identification of isolated bacteria was performed by 16S rDNA analysis. Results: The content of liquiritin and glycyrrhizin did not change according to the preservation temperature and period, but that of hesperidin was severely decreased at room temperature. The isolate from the decoction was identified as Bacillus licheniformis by 16S rDNA sequence analysis. Microbial population appeared after 3 months' preservation and reached maximum value at 4 months; at all tested temperatures, the pH showed the lowest value (4.4-4.5) simultaneously. Conclusion: From the results, it seems to be that the microbial growth affects the pH of preserved decoction but not the change of liquiritin and glycyrrhizin content.

• Korean Journal of Clinical Laboratory Science
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• v.44 no.4
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• pp.178-183
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• 2012

We investigated the latest trend of u-Health and relations with clinical technologist. Since 2000, Korea has become an aging society. Korea will become an aged society by 2018, and it is expected to enter the ultra-high aged society by 2026. Increase in over 65 years population means that the desire of medical service and care demand for the elderly is greatly required. In addition, many predicted Korean national health insurance would falter financially. Medical suppression policies and regulations are also amended continuously. U-Health based on the IT industry and development of related technologies and industries contains the variety concepts of telemedicine, telehealth, e-health, u-healthcare and POCT. Especially, the use of POCT supplied quick clinical examination is extending steadily in medical center and hospital, which will generate the field friction between nurses and medical technologists. In the transition situation from provider-centric service to consumer-driven health care system, this study recommended the principal role and correspondence of clinical laboratory workers and offered information about changes in healthcare market and the basic concept of expert system, measurement and the diagnosis principle to clinical technicians throughout the investigation of the recent research and government policy trends.

• Journal of Multimedia Information System
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• v.8 no.4
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• pp.277-284
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• 2021

Despite skepticism about commercial potential, the stereoscopic 3D cinema is still a form that any filmmaker can choose to employ for its aesthetics and its immersive potential. Based on a haptic illusion, the stereoscopic media content requires a new perspective different from the principle of 2D media content in terms of creation and acceptance. This paper examines the technical and aesthetic issues of stereoscopic 3D film production from the perspective of today's emerging realistic and immersive media through a case study. One of the key factors for successful content creation and research and development in stereoscopic 3D cinema is the combination of artistic principles together with technical mastering of the new image technology. The purpose of this paper is to outline the principal challenges and research topics in stereoscopic 3D cinema through a case study of stereoscopic 3D pilot film production for the 'User-Selective UHD Stereoscopic Media Service Platform' of the ETRI (Electronics and Telecommunications Research Institute). This paper intends to examine stereoscopic 3D filmmaking workflow and production methodologies, as well as technical elements and aesthetic issues.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1439-1446
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• 2011

This paper describes the algorithm that lowers the dimension, maintains the object recognition and significantly reduces the eigenspace configuration time by combining the higher correlation feature information and Principle Component Analysis. Since the suggested method doesn't require a lot of computation than the method using existing geometric information or stereo image, the fact that it is very suitable for building the real-time system has been proved through the experiment. In addition, since the existing point to point method which is a simple distance calculation has many errors, in this paper to improve recognition rate the recognition error could be reduced by using several successive input images as a unit of recognition with K-Nearest Neighbor which is the improved Class to Class method.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.815-822
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• 2004

A knowledge of in situ stress state is important to design various engineering structures such as dams, tunnels and so on. There are about three wellknown indicators that is, borehole will breakouts, hydraulic fracturing, ellipsoidal cross section of borehole that have been attributed to the state of stress in the vicinity of borehole. Fortunately, Televiewer traveltime image can be used as a caliper log with 144 or 288 arms, which allows to determine the borehole shape. Televiewer amplitude image will give detailed information about the distribution and character of breakouts and hydraulic fracturing as well. For investigation purposes, a series of boreholes(total 195 boreholes: 12.239m) that have been logged all over the country during past 10 years are analyzed. The primary objective of this paper are to examnine the ability of a Televiewer to determine the shape of borehole, to present data inferred by stress indicators, to indicate their possible relationship with the anisotropic horizontal stresses. It is shown that in most cases the fracture orientation statistically estimated from observed fractures denotes an excellent correlation with the orientations inferred by stress indicators. Many intervals of breakouts are terminated at the intersection of oblique fracture with the borehole. The results from Televiewer data are further compared with those of hydraulic fracturing techniques.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.703-708
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• 2022

K-means clustering is a representative clustering technique. However, there is a limitation in not being able to integrate the performance evaluation scale and the method of determining the minimum number of clusters. In this paper, a method for numerically determining the minimum number of clusters is introduced. The explained variance is presented as an integrated measure. We propose that the k-means clustering method should be performed in the subspace of the PCA in order to simultaneously satisfy the minimum number of clusters and the threshold of the explained variance. It aims to present an explanation in principle why principal component analysis and k-means clustering are sequentially performed in pattern recognition and machine learning.