• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.481-487
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• 2019

Additive manufacturing is a state-of-the-art manufacturing process technology in which three-dimensional structures are fabricated by laminating two-dimensional sections of a structure using various materials such as plastic, ceramics, and metals. The additive manufacturing technology has the advantage of high design freedom, while the surface property (roughness) of the finished product varies depending on the process conditions, which necessitates performing a post-process after the products are manufactured. In this study, the surface roughness of a structure made of polyamide 12, which was manufactured by SLS (Selective Laser Sintering) and MJF (Multi Jet Fusion) process was compared. The processing condition was classified by the building orientation of structure as 0, 45, and 90 degrees, which is the angle between the analytical surface and the horizontal plane of the fabrication platform. Structures with a hole of various diameters ranging from 1mm to 10mm were manufactured and the hole characteristics (ratio of hole depth to diameter) and results of the specimens were compared. As a result of the surface characteristics analysis, the surface roughness value of the specimens manufactured with a building orientation of $45^{\circ}$ was the highest in both technologies. In the case of the through-hole structure fabrication, the shape was maintained with 5mm and 10mm diameter holes regardless of the building orientation, although the hole forming was difficult for the smaller holes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.347-362
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• 2019

Underground excavation using TBM machines has been increasing to reduce complaints caused by noise, vibration, and traffic congestion resulted from the urban underground construction in Korea. However, TBM excavation design and construction still need improvement because those are based on standards of the technologically advanced countries (e.g., Japan, Germany) that do not consider geological environment in Korea at all. Above all, although TBM performance is a main factor determining the TBM machine type, duration and cost of the construction, it is estimated by only using UCS (uniaxial compressive strength) as the ground parameters and it often does not match the actual field conditions. This study was carried out as part of efforts to predict penetration rate suitable for Korean ground conditions. The effective parameters were defined through the correlation analysis between the penetration rate and the geotechnical parameters or TBM performance parameters. The effective parameters were then used as variables of the multiple regression analysis to derive a regression model for predicting TBM penetration rate. As a result, the regression model was estimated by UCS and joint spacing and showed a good agreement with field penetration rate measured during TBM excavation. However, when this model was applied to another site in Korea, the prediction accuracy was slightly reduced. Therefore, in order to overcome the limitation of the regression model, further studies are required to obtain a generalized prediction model which is not restricted by the field conditions.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.173-180
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• 2019

This study was conducted to understand factors affecting TSS and heavy metals transport on the road, parking lot and roof. During storm events, heavy metals, which were mostly attached to TSS, were also transported when TSS was washed off in the road, parking lot and roof. This finding may be supported by the significant correlations between TSS load and total and soluble heavy metals load including Cr, Fe, Cu, and Pb (Pearson r value: 0.52 to 0.73; probability p value<0.01). Generation and transport of TSS and heavy metals were greater in the road and parking lot compared to the roof due to vehicular activities, slope and greater catchment areas of these sites. It was found that TSS transport during peak flows of storm events ranges from 65% to 75% implying that by controlling peak flows, TSS transportation to nearby water bodies may be decreased. Depending on the target TSS and heavy metal reduction, sizing of low impact development (LID) technologies and green infrastructures (GI) such as infiltration trench, tree box filter, and rain garden may be calculated. Future researchers were recommended to assess the limitations of the systems and determine the design considerations for these types of facilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.272-278
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• 2018

Traffic volume has been greatly increasing due to urban development and the improvement of living standards, and many complaints are being raised due to the increasing road noise. As a countermeasure against these problems, highly soundproof walls are installed on the sides of roads. However, the ability to bear wind loads is a major design requirement for soundproof walls, which contributes to the exponential increases in construction costs and restricts the height of the walls. The aim of this study is to improve the performance of soundproof walls and to dramatically reduce wind loads while maintaining excellent price competitiveness. Based on Helmholz's resonator theory, a new concept is proposed for a ventilation-type soundproofing plate that can pass through a fluid like air and reduce noise. A full-scale metal soundproofing plate was produced to satisfy the quality standards of highways by conducting a sound-pressure transmission-loss test, wind tunnel test, and material quality test. To verify the reliability, the wall was manufactured and installed, and the sound insulation effect was examined by measuring the noise over time. In the future, ventilated soundproof walls on roads could create a pleasant living environment due to the high noise-insulation effect.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.281-302
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• 2021

Railway projects have been consistently increasing in Korea. In relation to this trend, the mechanized tunneling using Tunnel Boring Machine (TBM) is preferably applied for mining urban areas and passing under rivers. The TBM tunneling under difficult grounds like mixed faces with high water pressure could require ground improvements for stable TBM advance or safe cutter head intervention (CHI). In this study, pre-grouting works for CHI in Daegok-Sosa railway project are presented in terms of the grouting zone design, the executions and the results, the lessons learned from the experience. It should be mentioned that the grouting from inside TBM was carried out several times and turned out to be inefficient in the project. Therefore, grouting experiences from the surface are highlighted in this study. Jet grouting was implemented on CHI points on land, while permeation grouting off shore in the Han River, which mostly allow to access the cutter head of TBM in free air with stable faces. The results of CHI works have been analyzed and the lesson learned are suggested.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.45-52
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• 2018

Currently, apartments have become an important research subject for the overall area of politics, economics, and culture as well as urban architectural study. However, there are few analyses of the research trends related to the current interest in the apartment research and prediction of the future changes of an apartment in politics and industry. In this study, the research information related to the apartment has classified, and the changes in the research trends have analyzed. Based on the classified data, the first thesis and dissertation related to the apartment and changes of academic notation have discovered. In addition, future interests and future research directions through Frequency of Appearance, Degree Centrality Analysis, and Betweenness Centrality Analysis of author keywords were predicted. As a result of the analysis, 'Space,' 'Residential Mobility' and 'Apartment Complex' studies were found to be important research topics throughout the entire period. 'Han Gang Apartment,' 'Small Size Apartment,' 'Civic Apartments,' 'Jamsil,' and 'Child' were newly interested topics until 70's era. '(Super) High-rise Apartment,' 'Perception,' 'Jugong Apartment,' 'Housing Environment,' 'Housewife,' 'Apartment Layout,' and 'Busan' were newly interested topics during the 80's and 90's era. 'Apartment Price,' 'Energy,' 'Remodeling,' 'Noise,' 'Resident Satisfaction,' 'Community,' and 'Apartment Lotting-out' were newly interested topics after the year 2000. New concerns for last decade are found to be 'Super High-rise Apartment', 'Remodeling', 'Indoor'(2007), 'Apartment Reconstruction Project', 'Brand', 'AHP', 'Housing Environment'(2008), 'Ventilation'(2009), 'Apartment Lotting-out'(2010), 'Economic Assessment'(2011), 'Cost'(2012), 'Green Building', 'Apartment Sales', 'Law', 'Society'(2013), 'Floor Impact Noise', 'Seoul'(2014), 'Noise'(2015), 'Hedonic Model'(2016). In addition, following research topics are expected to be active in the future: In maturity stage of the research development is going to be 'Apartment Price', 'Space', 'Management of Apartment Housing'; the hedonic model, which is research growth and development stage, is going to be '(Floor Impact) Noise', 'Community', 'Energy.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.7
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• pp.109-117
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• 2019

Recently, child safety map making education has attracted attention as a way to reduce crimes against children. In Korea, the Ministry of Gender Equality and Family organized a child safety map making education program in 2011. The program's manual was revised in 2013 and the Ministry implemented it as a project to promote the rights of women and children. Child safety map making education aims to raise a child's understanding of their neighborhood, to have voluntary control and normal consciousness as a local inhabitant, to be aware of wrong behavior and crime, and to be part of creating a safe urban environment. However, when compared to educational programs in other major developed countries, the child safety map making education program in Korea currently does not improve a child's awareness of their surroundings. In this workshop study, we proposed and ran a new program to improve children's awareness of their environment based on the active participation of children in the existing safety map educational program. The workshop was held for 4 weeks for 48 students from 5th and 6th grade at Osan Daeho Elementary School. We analyzed this new program's effects with the following results. First, an analysis of the effects of the program on children's recognition of safe and dangerous spaces revealed that their understanding of these spaces increased by 30.4% after the workshop. The safety-related factor in the mind map key concept increased from 0.94 to 4.94, indicating that the children's perception of neighborhood risk and safety factors improved. Second, the analysis of the effects of the program on the children's coping ability in dangerous situations showed that their understanding of how to deal with dangerous situations increased by 11.3%. The children's understanding of facilities they could ask for help, such as police boxes and child safety guard houses, improved by 17.9%. Third, analysis of the effects of child safety map making education on children's understanding of their neighborhood, their perception of responsibility in the neighborhood, and their neighborhood attachment showed that these levels of children's understanding of the neighborhood improved by 6.0% after the workshop.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.19-27
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• 2011

By studying 'Sauidangzi' written by Honggyungmo(1774~1851), this paper shows on the location, the space organization, and the landscape culture of 'Sauidang' which was upper class's house in late period of the Joseon. Sauidang was the residence of about 530 kan(about $1,750m^2$) which was given to Jeongmyunggongju(daughter of Sunzo) by Injo when she married with Hongjuwon, located at the good place where Mt. Mokmyuk, Mt. Dobong, Mt. Inwang, and Janwon peak are harmonized all together. The residence was on the foothill of Mt. Mokmyuk, facing to the northeast. The main house was facing to the east with the inner and back yards, and the separate house(Sauidang) was facing to the west with the garden, and a vegetable field was set in the outer yard where is connected with a main road where willow trees were lined up, 'Sauidang' was called as "the garden of princess", and a stair-shaped flower garden was made to the south, and one could look down the Hanyang castle as a whole. In the garden, there were trees and house plants enriching one's mind to wish an eternal life with oddly shaped stones or flowers, and symbolizing a fairly land. There were 38 types of trees that were planted either on the ground or in pots as various bundles like 1 tree, 2 trees, 3 trees, 4 trees, 5 trees, 8 trees, and 9 trees. Taehosuk, oddly shaped stones, stone panels, stone pillars, jade panels, sundial, walls and fences, stone stairs, steppingstones, and buildings were set for the landscape. Also, the residence had rare luxuries of landscaping culture like Wangheeji's Nanjungsoogyeseo, Sosik's Cheeongjeongi, Jomangboo's Jeokbyukboo, and Anpyungdaegoon's Behaedangcheop.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.73-80
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• 2011

The study reviewed the content and the meaning of the present Yeoju Palkyung(eight scenery) through analyzing and interpreting the Palkyung poems, old maps and paintings, and classic materials transmitted in Yeoju area, and investigated the landscape structure of the area around the Cheongshimru(淸心樓: pavilion). On the other hand, many Palkyung poems and Noojeongjeyong(樓亭) poems illustrating the Cheongshimru as the view point or the objective have clarified the scenic excellence when the Cheongshimru is the view point. The Yeoju Palkyung viewed from the Cheongshimru was described as constructing all around allocation structure, and six scenes are categorized as a distant view of the visual influence while the 7th scene Ireungdogyeon and the 8th scene Pasagwau are a psychologically influencing landscapes. The panoramic composition of the Yeoju Palkyung at the Cheongshimru is interpreted as the Seunggyeong distribution considering Palchaejigyeongsaek(八采之景色), where main viewpoint is the Cheongshimru and the distant landscape is Paldaejangrim. The reputation of the Cheongshimru, the central place of the Yeoju Palkyung, is confirmed by the technique of scene processing describing a various way of illustrating landscapes such as near view, distant view, pulling view and collecting view. The restoration of Cheongshimru and Paldaesup(八大藪) currently undertaken is the essential business for the full recovery of the Yeoju Palkyung, which will be not only for physical restoration but also for the shortcut to revitalize the history and the spirit of Yeoju. Furthermore, the business direction should be reconsidered to truly understand the meaning, the value, and the structure of the Yeoju Palkyung to ensure the pursuit of the sustainability aiming at the project "Local attractions", one of the Namhangnag Four rivers project of the ministry of Land, Transport and Maritime Affairs.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.90-98
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• 2011

This study aims to discuss the characteristics of garden architecture in Italian Renaissance Villa Lante that was constructed by the cardinal in Bagnaia at 16th century through actual survey and analysis of the garden's elements. To do this, it was studied in two ways: Analysis of the present conditions and review historical documents. The results are as follows. First, the buildings, the gardens and the surrounding landscapes are visually connected each other in relations between the topography and the surrounding landscapes. Second, the spatial composition accepted Neoplatonic law of multiple proportions and was influenced by ancient myth and "Liber ruralium commodorum" of Pietro de Crescenzi(1305). Third, the garden's elements consist of plants, buildings and items. In plants, the upper plants are fir tree, cypress and pine tree and the lower plants are english holly, box tree and sweet oleander. The buildings are casino, loggia and terrace. The items are pot, sundial, chair, viewing platform and fountain. The result of this study, the political and social, technical phenomena which constitute construction pattern affected the locational property and the spatial organization of the neighbor on Villa Lante.