• Korean Journal of Plant Taxonomy
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• v.37 no.3
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• pp.255-273
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• 2007

The morphological characters for 4 taxa of Korean Symplocaceae were examined. Based on morphological examination, numerical analysis was performed to clarify the taxonomic relationships among the taxa. It was found that epidermal characters of leaves, cellular deposition of petals, cellular boundary of petioles, growth of stigmas and pollen grains and their surfaces were useful diagonostic characters. From the results of PCA analysis, four taxa were grouped as species clusters including each populations. Four species of Symplocos were clustered as species groups with clear delimitation. Morphological, numerical, and palynological analyses supported the previous morphological studies on this family.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.48-56
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• 2010

Since ancient times, Korea has been called a land of beauty. Scenic sites under the Cultural Properties Protection Act include picturesque places that are famous for their natural scenic beauty as well as their historical and cultural value. Scenic sites are managed as natural assets to promote their preservation and use. However, the management of scenic sites can produce adverse effects on regional development and ownership rights. Moreover, the purpose of their designation as cultural assets is not fully understood because scenic sites are managed by focusing on restraint on users' act the same as was applied to historic sites. Therefore, the purpose of this study is to protect inhabitants' rights of ownership by arranging the boundaries of designated areas and by providing standard permission for condition changes in the Buryeongsa Valley, which was designated as a Scenic Site in 1979. The results of this study can be summarized as follows: First, arranging the boundaries of the designated area includes the arrangement of the edge lines standardized on the visual range of the mountain ridge, preventing the loss of landscape beauty in the designated district; the internal clearing district focuses on the existing settlement. Gearing the designated areas after the arrangement of the boundaries results in $11,928,932m^2$, 38.6% compared to the existing designated areas. Second, it establishes a 500m buffer zone inside the radius of the boundary of the cultural asset as a standard for condition changes that seriously affect landscape preservation. Third, the standards for permission on building 'height regulations' are divided into flat and gable, according to the roof shape. The adopted standard is 8m high for 2 story flat roofs, and 12m high for 2 story gable roofs.

• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.57-65
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• 2012

Various numerical methods in simulation of seismic wave propagation have been developed. Recently an innovative numerical method called as the Spectral Element Method (SEM) has been developed and used in wave propagation in 3-D elastic media. The SEM that easily implements the free surface of topography combines the flexibility of a finite element method with the accuracy of a spectral method. It is generally used a weak formulation of the equation of motion which are solved on a mesh of hexahedral elements based on the Gauss-Lobatto-Legendre integration rule. Variational formulations of velocity-stress motion are newly modified in order to implement ADE-PML (Auxiliary Differential Equation of Perfectly Matched Layer) in wave propagation in 3-D elastic media, because a general weak formulation has a difficulty in adapting CFS (Complex Frequency Shifted) PML (Perfectly Matched Layer). SEM of Velocity-Stress motion having ADE-PML that is very efficient in absorbing waves reflected from finite boundary is verified with simulation of 1-D and 3-D wave propagation.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.6
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• pp.67-86
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• 2009

In this study, a 3D transmitting boundary in water-saturated transversely isotropic soil strata has been developed based on u-w formulation for application to general 3D analysis. Behavior in the far field region is expanded in the Fourier series, and dynamic stiffness for each term is obtained based on the u-w formulation. Transformation of the dynamic stiffness is presented to combine the transmitting boundary with the 3D finite elements for the near field region formulated in a 3D Cartesian coordinate system. The developed transmitting boundary is verified through a comparison of the dynamic behavior of a rigid circular foundation with the results from the existing numerical method. In addition, the developed transmitting boundary is applied to the analysis of the dynamic behavior of rigid foundations of diverse shapes, and the effects of the level of the groundwater table on the dynamic stiffness of a rigid rectangular foundation in the water-saturated transversely isotropic layered stratum are studied.

• Journal of the Korean earth science society
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• v.31 no.1
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• pp.88-94
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• 2010

A simple laboratory device and methodology are developed for deep understanding of the western boundary current (WBC). The apparatus consists of a rotating (count-clockwise) rectangular tank with a sloping bottom in order to simulate the beta effect, the variation of the Coriolis parameter with latitude. We also used a clockwise rotating disk at the surface water to mimic the wind stress forcing in mid-latitude oceans. Four experiments were carried out using some combination of a bottom type and a rotation of the tank. Experiment with the beta effect clearly demonstrated the WBClike flow as well as the Sverdrup interior. However, the water in a tank gave rise to an inertial motion under the influence of a constant Coriolis force alone. We also discussed a stiffening of the rotating fluid on the basis of the Taylor-Proudman effect. We believe that the apparatus and methods developed in this study help to understand the WBC due to the beta effect.

• Journal of KIISE:Software and Applications
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• v.27 no.3
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• pp.201-209
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• 2000

Recent works regarding video shot change detection algorithms show that abrupt shot changes are detected fairly well. However, gradual shot changes including wipes and dissolves are often missed or falsely detected. A robust shot change detection system, therefore, must include a shot verification step to further enhance the overall system performance. In this paper, we introduce the concept of the visual rhythm which is a single image, a subsampled version of a full video. On the visual rhythm, the different video edit effects such as cuts, wipes and dissolves manifest themselves as different patterns. Using this characteristic, it becomes possible, without sequentially playing the entire video, to find false positive shots as well as undetected shots. Thus, inclusion of the visual rhythm in the shot boundary verification process will aid the operator to exclude falsely detected shots as well as to find undetected shots fast and efficiently. For this purpose we have developed a new tool, a shot verifier incorporating the visual rhythm. The usefulness of the visual rhythm during the shot verification process will be presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.7
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• pp.481-487
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• 2017

The interaction between a shock wave and a boundary layer causes boundary layer separation, shock train, and in some cases, strong unsteadiness in the flow field. Such a situation is also observed in a shock tube, where the reflected shock wave interacts with the unsteady boundary layer. However, only a few studies have been conducted to investigate the shock train phenomenon in a shock tube. In the present study, numerical studies were conducted using the two-dimensional axisymmetric domain of a shock tube, and compressible Navier-Stokes equations were solved to clarify the flow characteristics of shock train phenomenon inside a shock tube. A detailed wave diagram was developed based on the present computational results, which were validated with existing experimental data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.10
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• pp.1305-1313
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• 2013

In this study, a method to apply feature-based simplification to boundary representation models is proposed. For feature-based simplification, a volume decomposition tree is created from a boundary representation model. The volume decomposition tree is represented by regularized Boolean operations of additive volumes, subtractive volumes, and fillet/round/chamfer volumes, and it is generated by stepwise volume decomposition, which consists of fillet/round/chamfer decomposition, wrap-around decomposition, volume split decomposition, and cell-based decomposition. After the volume decomposition tree is transformed to an infix expression, the CAD model can be simplified by reordering the volumes. To verify the proposed method, a prototype system was implemented, and experiments on test cases were conducted. From the results of the experiments, it is verified that the proposed method is useful for simplifying CAD models based on boundary representation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.4
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• pp.421-429
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• 1999

It is estimated that, in the twenty-first century, 70％ of global citizens will live in urban areas. This accelerated urbanization will require a greater need for the building DEM and orthoimagery along with Geographic Information System for urban management. The building DEM requires the detection of outlines showing building shapes. To do this, automatic and semiautomatic building extractions are usually used. However, in cases where automatic extraction is performed directly from the aerial images, accurate building outline extraction is very difficult because of shadow, roof color, and neighboring trees making it hard to discern building roofs. To overcome this problem semiautomatic building extraction was suggested in this paper. When a roof texture was homogeneous, building outline detection was performed by mouse-clicking on a part of the roof. To construct the building outlines when the texture was not homogeneous, a computer program was developed to search out corner points by clicking spots near corner points. The building DEM was generated by taking into account building outlines and heights calculated by image matching.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.139-152
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• 2004

This paper proposes to improve the results of image classification with spatial region growing segmentation by using an MRF-based classifier. The proposed approach is to re-classify the pixels in the boundary area, which have high probability of having classification error. The MRF-based classifier performs iteratively classification using the class parameters estimated from the region growing segmentation scheme. The proposed method has been evaluated using simulated data, and the experiment shows that it improve the classification results. But, conventional MRF-based techniques may yield incorrect results of classification for remotely-sensed images acquired over the ground area where has complicated types of land-use. A multistage MRF-based iterative class-modification in boundary is proposed to alleviate difficulty in classifying intricate land-cover. It has applied to remotely-sensed images collected on the Korean peninsula. The results show that the multistage scheme can produce a spatially smooth class-map with a more distinctive configuration of the classes and also preserve detailed features in the map.