• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.779-797
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• 2017

Recently, underground road construction is attracting attention because the ground transportation facilities in the urban area have reached the saturation level and traffic volume has increased and the air pollution has risen. Construction of underground roads is not only reduce trafficjam in downtown but also design the city eco-friendly, so existing roads as well as new roads go underground. It is essential to construct divergence tunnels that serve as IC (interchage) and JC (Junction) when constructing underpasses. Therefore, the analysis of the effect of the existing tunnel by the divergence tunnel should be considered. In this study, numerical analysis is performed to analyze the effect of existing tunnel on the excavation of the divergence tunnel. The divergence tunnels were set in 5 cases at $45^{\circ}$ intervals in the clockwise direction starting from the lower part of the existing tunnel. In each case, numerical analyses were carried out by using the DCM (Displacement Controlled Model) for applying the volume loss of 0.5%, 1.0% and 1.5%. As a result, when the volume loss increased, the effect on displacement, fracture range, and effect on stability increased as well. In addition, it was confirmed that the divergence tunnel located directly underneath is the weakest for the stability, and the case where the divergence tunnel is located diagonally rather than the vertical and horizontal direction is found to be vulnerable to displacement and lining destruction.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.212-235
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• 2010

The purpose of this study is to examine the characteristics of the location and the spatial composition of Uireung that is located in Seokgwan-dong, Seongbuk-gu, Seoul, in order to understand the landscape architectural characteristics. The results are as follows. First, Uireung is 6.4km from Changdeokgung Palace and 5.5km from Heunginjimun Gate. It did not violate the distance standard (40km) for the royal tombs according to Joseon Dynasty Neung-won Myo-je. Second, Uireung is in harmony with the nature and shows the authoritative characteristics of the royal authority through the spatial composition and rank(Entrance Area, Ceremonial Area, Burial Area). Third, there are burial mound, stone sheep, stone tiger, stone table, stone watch pillars in the upper platform, and stone civil official, stone horse, stone lantern in the middle platform, and stone military official, stone horse in the lower platform, and T-shape shrine, worship road in the ceremonial area. There is no pond and a tomb keeper residence, but the position, size, and form can be approximated through historical research materials. There are a colony of pine trees around the burial mound and 64 species of trees such as pine tree, zelcova tree, and fir tree below the burial mound.

• 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 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.1019-1023
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• 2006

The slope information based on DEM is very useful for urban planning, landscape, road design and water resource areas such as rainfall-runoff and soil erosion estimation. The resolution of slope, which is from DEM, can be variously decided by an application fields and the kinds of modeling method. In particular, the more decreased resolution makes the more decreased slope value because of the increased horizontal distance. This study presents slope evaluation method by aggregation method based on discharge and Manning's velocity equation to advance the loss of slope information in according to the resolution, and then applied it to calculate topographic factors of soil erosion model. As a result, conventional method shows 34.8% errors but aggregation method shows 12.6% errors. This study selected up-, middle-, and downstream region in watershed and analyzed the capability of aggregation method in order to estimate the influence of topographic characteristics. As a result of estimation, aggregation method shows more advanced results than conventional method. Therefore, the slope evaluation method by aggregation method can improve efficiently the loss of slope information in according to the variation of resolution in water resource area such as rainfall-runoff model.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.266-279
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• 2014

For the evaluation of roadway safety, diverse methods, including before-after studies, simple comparison using historic traffic accident data, methods based on experts' opinion or literature, have been applied. Especially, many research efforts have developed traffic accident prediction models in order to identify critical elements causing accidents and evaluate the level of safety. A traffic accident prediction model must secure predictability and transferability. By acquiring the predictability, the model can increase the accuracy in predicting the frequency of accidents qualitatively and quantitatively. By guaranteeing the transferability, the model can be used for other locations with acceptable accuracy. To this end, traffic accident prediction models using non-linear regression, artificial neural network, and structural equation were developed in this study. The predictability and transferability of three models were compared using a model development data set collected from 90 signalized intersections and a model validation data set from other 33 signalized intersections based on mean absolute deviation and mean squared prediction error. As a result of the comparison using the model development data set, the artificial neural network showed the highest predictability. However, the non-linear regression model was found out to be most appropriate in the comparison using the model validation data set. Conclusively, the artificial neural network has a strong ability in representing the relationship between the frequency of traffic accidents and traffic and road design elements. However, the predictability of the artificial neural network significantly decreased when the artificial neural network was applied to a new data which was not used in the model developing.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.1007-1018
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• 2009

Hydrocyclone is widely used in industry, because of its simplicity in design, high capacity, low maintenance and operational cost. The separation action of a hydrocyclone treating particulate slurry is a consequence of the swirling flow that produces a centrifugal force on the fluid and suspended particles. In spite of hydrocyclone have many advantage, the application for treatment of urban stormwater case study were rare. We conducted a laboratory scale study on treatable potential of micro particles using hydrocyclone filter (HCF) that was a combined modified hydrocyclone with perlite filter cartridge. Since it was not easy to use actual storm water in the scaled-down hydraulic model investigations, it was necessary to reproduce ranges of particles sizes with synthetic materials. The synthesized storm runoff was made with water and addition of particles; ion exchange resin, road sediment, commercial area manhole sediment, and silica gel particles. Experimental studies have been carried out about the particle separation performance of HCF-open system and HCF-closed system. The principal structural differences of these HCFs are underflow zone structure and vortex finder. HCF was made of acryl resin with 120 mm of diameter hydrocyclone and 250 mm of diameter filter chamber and overall height of 800 mm. To determine the removal efficiency for various influent concentrations of suspended solids (SS) and chemical oxygen demand (COD), tests were performed with different operational conditions. The operated maximum of surface loading rate was about 700 $m^3/m^2$/day for HCF-open system, and 1,200 $m^3/m^2$/day for HCF-closed system. It was found that particle removal efficiency for the HCF-closed system is better than the HCF-open system under same surface loading rate. Results showed that SS removal efficiency with the HCF-closed system improved by about 8~20% compared with HCF-open system. The average removal efficiency difference for HCF-closed system between measurement and CFD particle tracking simulation was about 4%.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.90-103
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• 2009

The poem 'Kyungjusipiyung(慶州十二詠)' written by Seo, Geo-jeong(徐居正) describes sentiments felt for the ruined historical and cultural landscape of Silla's capital city, Kyungju. It differs from the existing 'Eight Sceneries(八景)' as it conveys the strong metaphorical aesthetics of ruins as the episodes and figures are sung, as well as the myths and stories related to the representative holy places of the Silla culture: Gyelim(鷄林), Banwolseong(半月城), Najeong(蘿井), Oneung(五陵), Geumosan(金鰲山), the scenic beauty of deep placeness, Poseokjeong(鮑石亭), Mooncheon(蚊川), Cheomseongdae(瞻星臺), Boonhwangsa(芬皇寺), Youngmyosa(靈妙寺) and Grave of the General Kim Yu-Sin(金庾信墓). Compared with the former "Eight Sceneries" Poems, including Seo Geojeong's 'Kyungjusipiyung', there is a difference in the content of theme recitation, as well as in structure and form, especially with the deep impression of the classical features of the meanings and acts. The sequence of theme recitation seems to be composed of more than two visual corridors visited during trips that last longer than two days. The dominant emotions expresses in this poem, through written in the spring, are regret and sadness such as 'worn', 'broken and ruined', 'old and sad', without touching on the beauty of nature and the taste for life that is found in most of the Eight Sceneries Poems. Thus, the feelings of the reciter himself, Seo, Geo-jeong, about the described sceneries and their symbolism are more greatly emphasized than the beauty of form. The characteristic aspect of his experiences of ruins expressed from 'Kyungjusipiyung' is that the experiences were, first of all, qualitative of the aura conveyed; that is, the quality omnipresent throughout the culture of Silla as reflected in the twelve historical and cultural landscapes. In this poem, the cultural ruins of the invisible dimension such as the myths and legends are described by repetition, parallelism, juxtaposition, reflection and admiration from the antiphrases, as well as the civilized ruins of the visible dimension such as the various sceneries and features of Kyungju. This seems to be characteristic of the methods by which Seo, Geo-jeong appreciates 'Silla' in the poem 'Kyungjusipiyung'. Ruins as an Aesthetic Object imply the noble pride of Seo, Geo-jeong in identifying himself with the great nature of ruins. In 'Kyungjusipiyung', the images of the ruins of Silla and Kyungju are interspersed in spite of his positive recognition of 'the village of Kyungju' based on his records. However, though the concept of ruins has a pessimistic tone connoting the road of extinction and downfall, the aspect here seems to ambivalently contain the desire to recover and revive Kyungju through the Chosun Dynasty as adominant influence on the earlier Chosun's literary tide. The aesthetics of the scenery found in Seo, Geo-jeong's 'Kyungjusipiyung' contain the strongest of metaphor and symbolism by converting the experiences of the paradoxical ruins into the value of reflective experiences.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.347-365
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• 2020

In order to resolve traffic problems in urban areas and to increase the area of green spaces, tunnels in downtown areas are being increased. Additionally, the application of large port smoke extraction ventilation systems is increasing as a countermeasure to smoke extraction ventilation for tunnels with high potential for traffic congestion. It is known that the smoke extraction performance of the large port smoke extraction system is influenced not only by the amount of the extraction flow rate, but also by various factors such as the shape of the extraction port (damper) and the extraction air velocity through a damper. Therefore, in this study, the design standards and installation status of each country were investigated. When the extraction air flow rate was the same, the smoke extraction performance according to the size of the damper was numerically simulated in terms of smoke propagation distance, compared and evaluated, and the following results were obtained. As the cross-sectional area of the smoke damper increases, the extraction flow rate is concentrated in the damper close to the extraction fan, and the smoke extraction rate of the damper in downstream decreases, thereby increasing the smoke propagation distance on the downstream side. In order to prevent such a phenomenon, it is necessary to reduce the cross-sectional area of the smoke damper and increase the velocity of passing air through the damper so that the pressure loss passing through the damper increases, thereby reducing the non-uniformity of smoke extraction flow rate in the extraction section. In this analysis, it was found that when the interval distance of the extraction damper was 50 m, the air velocity passing through damper was 4.4 m/s or more, and when the interval distance of the extraction dampers was 100 m, the air velocity passing through damper was greater than 4.84 m/s, it was found to be advantageous to ensure smoke extraction performance.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.97-110
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• 2012

This study aimed at considering the original shape of Iljiam Tea Garden at Mt. Daedun. In order to accomplish our goal, we tried to strengthen the authenticity of construction of Iljiam by comparing its space structure depicted in the poetry of Choeui(艸衣) the monk with its current restored state. According to the clues and situation in the poetry along with symbolic words like 'Choeui' and 'Ilji(一枝)', Iljiam seemed to be a tea garden with elegant and celestial beauties, and with a nice view where Choeui the famous monk searched for the highest state of enlightenment by enjoying and living in nature. When we compared the plural aspects of Iljiam like Dacheon(茶泉), Dajo, Mulhwak, Darim(茶林), Chaewon(菜園), and Yeonji(蓮池) with those of Dasan Tea Garden[茶山草堂], we could see that the basic components of tea-culture space of both gardens are the same, showing the organizational principle of the top and bottom area to stress reading and studying. When it is restored, the authenticity of Iljiam should be pursued by linking spatial, historical, and landscaping characteristics as the space of which Choeui the monk carried out Zen meditation and mastered tea. However, the recent grand scale Buddhist business like the expansion of access road and construction of Buddhist sanctuary and Seolimdang became the biggest threat to the authenticity. Especially, it was emphasized many times in various poetry that the view from Iljiam and its surroundings is extraordinary, so it is critical to get rid of obstacles to the view from Iljiam and its surroundings in order to restore Iljiam as its genuine form. The current Iljiam should be re-made because it is like a leaf-roofed garden, not like a hermitage. However, the opinion that Jawoohongryeon-sa(紫芋紅蓮社) is somewhat a Taoistic and Taoist hermit space with a special shape adopted the pattern of building of the Joseon period rather than a Buddhist building can be accepted as long as other convincing historical evidences are found out, considering the ideology of uniting Confucianism and Buddhism and the spirit of Taoist hermit found out from poetry of Choeui and his friends. In conclusion, the restoration of Iljiam in 1979 was carried out to restore the place of Iljiam rather than to restore the originality of Iljiam by combining and referring domestic cases of tea gardens. However, there is not much material for restoration even though the main frame of Iljiam was distorted. Nevertheless, the top and bottom ponds should be constructed as a rectangle shape. In addition, it can be improved much in terms of plants and trees. It is necessary to restore bamboo forest, which was razed in order to make a tea plantation around Seolimdang, to set vines of arbors above the upper limbs, to plant pine trees and willow trees inside of the garden, and to put Dajeolgu under the corner of the eaves. Especially, the bamboo forest emphasized in poetry and took care of by Choeui himself should be restored inside of the garden.