• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.5
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• pp.221-230
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• 2023

This study proposes a methodology for assessing seismic liquefaction hazard by implementing high-resolution three-dimensional (3D) ground models with high-density/high-precision site investigation data acquired in an area of interest, which would be linked to geotechnical numerical analysis tools. It is possible to estimate the vulnerability of earthquake-induced geotechnical phenomena (ground motion amplification, liquefaction, landslide, etc.) and their triggering complex disasters across an area for urban development with several stages of high-density datasets. In this study, the spatial-ground models for city development were built with a 3D high-precision grid of 5 m × 5 m × 1 m by applying geostatistic methods. Finally, after comparing each prediction error, the geotechnical model from the Gaussian sequential simulation is selected to assess earthquake-induced geotechnical hazards. In particular, with seven independent input earthquake motions, liquefaction analysis with finite element analyses and hazard mappings with LPI and LSN are performed reliably based on the spatial geotechnical models in the study area. Furthermore, various phenomena and parameters, including settlement in the city planning area, are assessed in terms of geotechnical vulnerability also based on the high-resolution spatial-ground modeling. This case study on the high-precision 3D ground model-based zonations in the area of interest verifies the usefulness in assessing spatially earthquake-induced hazards and geotechnical vulnerability and their decision-making support.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.139-155
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• 2019

The Plays of Kang Yang Won and the Theatre Troupe Dong don't aim to use the body as a system of sign in order to express the mind. They want to show the physical presence of an actor which induces sensuous perception of audience, so the possibility of the aesthetics of performativity can be open. Therefore, the properties of body sound and space have important meaning. At the same moment the body of audience has to be open to the perception. It means that the audience has to be ready to perceive the energy breathing density and tension etc. which the body of actor causes. As a result, the audience experiences a simultaneous opening of consciousness and perception: simultaneous opening of consciousness and perception gives the chance of receiving the emergent meaning.

• Journal of the Korea Computer Graphics Society
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• v.16 no.1
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• pp.9-20
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• 2010

In order to visualize participating media in 3D space, they usually calculate the incoming radiance by subdividing the ray path into small subintervals, and accumulating their respective light energy due to direct illumination, scattering, absorption, and emission. Among these light phenomena, scattering behaves in very complicated manner in 3D space, often requiring a great deal of simulation efforts. To effectively simulate the light scattering effect, several approximation techniques have been proposed. Volume photon mapping takes a simple approach where the light scattering phenomenon is represented in volume photon map through a stochastic simulation, and the stored information is explored in the rendering stage. While effective, this method has a problem that the number of necessary photons increases very fast when a higher variance reduction is needed. In an attempt to resolve such problem, we propose a different approach for rendering particle-based volume data where kernel smoothing, one of several density estimation methods, is explored to represent and reconstruct the light in-scattering effect. The effectiveness of the presented technique is demonstrated with several examples of volume data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1180-1187
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• 2006

We Studied the method of structuring the sign system for pedestrians in the underground space by investigating and analyzing the sign system at Tae-jon Underground Commercial Area in Korea by 1) classifying the signs by types and comparing their numder for each type in sections, 2) classiflying the signs by the points of installation, types, functions and contents of information and comparing their numbers, 3) classifying the signs by their height and comparing by the points of installation, and 4) classifying the signs by their points of installation finding patterns. As a result, we found out that the current pedestrian signs in Tae-jon Underground Commercial Area could by classified into those installted with a certain regularity and those concentrated in at certain points. We also found out that there were many problems with the current signs system. The big gap of the type and numble of the signs, concentration of the signs at the gate (entrance), and the big gap of the function of the signs by their points of installation. And the gap of the signs by the number of installation is big between the North side and the South side. Most of signs concentrated in the South side show the problems of installation attached by the types and quantity of information. We suggest that type of information has consistency by posting of signs, at the same time, the necessary information should be offered in order for the pedestrians to easily recognize as they more in the Underground space.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.5
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• pp.1131-1141
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• 2015

In this paper, we proposed a new approach of machine learning based method for detecting game-bots from normal players in MMORPG by inspecting the player's action log data especially in-game money increasing/decreasing event log data. DBSCAN (Density Based Spatial Clustering of Applications with Noise), an one of density based clustering algorithms, is used to extract the attributes of spatial characteristics of each players such as a number of clusters, a ratio of core points, member points and noise points. Most of all, even game-bot developers know principles of this detection system, they cannot avoid the system because moving a wide area to hunt the monster is very inefficient and unproductive. As the result, game-bots show definite differences from normal players in spatial characteristics such as very low ratio, less than 5%, of noise points while normal player's ratio of noise points is high. In experiments on real action log data of MMORPG, our game-bot detection system shows a good performance with high game-bot detection accuracy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5191-5198
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• 2010

Although numerous studies have analyzed the relationship between subway travel demand (STD) and various characteristics of subway catchment area (SCA), a few studies examined the relationship between STD and the structure of pedestrian networks within each SCA. Hence, this study evaluates the structure of pedestrian networks within 79 SCAs in the city of Busan using Space syntax and investigates the relationship between STD and several characteristics of SCA including the spatial structure of pedestrian network. The analysis results show that the spatial integration of pedestrian networks within the SCAs, which represents the magnitudes of walking accessibility to subway station, is positively associated with STD among the three spatial indexes such as integration, connectivity, and intelligibility. In addition, the results show that STD significantly increases as the number of travel gathering facilities and the average floor area ratio within the SCAs increase. This study ultimately corroborates that designing the grid pedestrian network and assigning the travel gathering facilities to the compact buildings within SCAs are needed to ameliorate the spatial structure of SCA in the city of Busan as transit-oriented development system.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.4
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• pp.36-47
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• 2008

The purpose of this study is to classify and assess the characteristics of urban Korean parks by on-site park users' reactions, such as satisfaction, preference and cognitive image of the park and park facilities. The park facilities are classified into five types of satisfaction: management status, activity facilities, convenient facilities, circulation and density, and landscape facilities. The park users are satisfied with conversation, rest and relaxation in the parks, but not satisfied with studying and nature experience. The behaviors in the park are classified as park activities, emotional and experiential activities, and nature activities. The results indicate that the images of the parks are stable, comfortable and natural. There are three factors to classifying the park images: nature-harmony, openness, uniqueness. Preferences for each parks are generally good. According to the criteria such as satisfaction of park facility, behavioral satisfaction, images and preference for each park, the 12 parks are divided into 5 different types: multi-purpose park, well-balanced park with natural elements, urban open space, park to be improved, and ecological park. The characteristics of each park was analyzed and categorized. This study dealt with only the parks in Seoul and its environs, and the survey was only done during the summer season. Therefore, further research is necessary to enlarge and generalize the results of this study, considering seasonal and regional variations.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.355-373
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• 2017

Tunnelling in urban areas, it is essential to understand existing structure-tunnel interactive behavior. Serviced structures in the city are supported by pile foundation, since they are certainly effected due to tunnelling. In this research, thus, pile load distribution and ground behavior due to tunnelling below grouped pile were investigated using laboratory model test. Grouped pile foundations were considered as 2, 3 row pile and offsets (between pile tip and tunnel crown: 0.5D, 1.0D and 1.5D for generalization to tunnel diameter, D means tunnel diameter). Soil in the tank for laboratory model test was formed by loose sand (relative density: Dr = 30%) and strain gauges were attached to the pile inner shaft to estimate distribution of axial force. Also, settlements of grouped pile and adjacent ground surface depending on the offsets were measured by LVDT and dial gauge, respectively. Tunnelling-induced deformation of underground was measured by close range photogrammetric technique. Numerical analysis was conducted to analyze and compare with results from laboratory model test and close range photogrammetry. For expression of tunnel excavation, the concept of volume loss was applied in this study, it was 1.5%. As a result from this study, far offset, the smaller reduction of pile axial load and was appeared trend of settlement was similar among them. Particulary, ratio of pile load and settlement reduction were larger when the offset is from 0.5D to 1.0D than from 1.0D to 1.5D.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.795-810
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• 2019

In this paper, The study was conducted on the method to roughly determine the area and length of the multi-utility tunnel before the planning and design phase of the multi-utility tunnel construction. For this purpose, four feasibility indexes were used: traffic density, population density, disaster prevention index (number of workers), and urbanization rate, which reflect the regional characteristics. The installation criteria were set in consideration of the average value and minimum value of the feasibility indexes for the tunnel type among areas that can be installed in the multi-utility tunnel of Seoul. The analysis area included 200 areas based on 14 zones. The results of the analysis based on the minimum value of feasibility indexes indicated that the tunnel type of multi-utility tunnel is suitable for 39 areas with high traffic volume and population. On the other hand, the 'gun' area, etc., has a wider population than the 'si' and 'gu', suggesting that it is not suitable to install multi-utility tunnel. In addition, it can be seen that the larger the index value centered on the minimum value of each index, the smaller the tunnel type of multi-utility tunnel installation area.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.217-221
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• 2007

To provide the basic data essential for developing varieties of broad-leaved tree, the study investigated the utmost growth requirement for the growth characteristic and biomass production in accordance with planting density of Styrax obassia. The planting density of seedling can be a significant factor in contributing growth of seedling for tree growing in general. While growth of tree according to $1m^2$ planting density of Styrax obassia showed an excellent growth in tree height and the root collar diameter from $49no./m^2$, those low planting density showed decreased tendency with tree height growth while increasing the root collar diameter growth. As similar to the growth characteristic, the biomass production showed significant and statistic difference in $49no./m^2$, showing high volume of biomass production which is $3.12{\pm}0.80g$ compare to other processing section and high figure with T/R ratio which is 1.59. The special trait of photosynthetic also showed relatively high photosynthetic rate in $49no./m^2\;and\;64no./m^2$ of Styrax obassia and as the density increase, photosynthetic efficiency decreased. The plant showed stable and physiological planting pattern, displaying the best photosynthetic rate, which was the final metabolism through reserving proper space in the growth and development environment condition. This obstacle of required space essential for growth substantially deteriorated planting and ultimately, it demonstrated lower tendency of photosynthetic rate, which is the highest level of metabolism.