• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.323-331
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• 2018

This study was conducted to examine the effects of constructing streetside urban forests on particulate matter (PM) content in pedestrian paths and open spaces created between the main streets and buildings in a high-rise, high-density urban area. The study site is a 70m-wide open space between Busan City Hall and Jungang-street in Busan, Korea. The results showed that the density of PM differences between the open space and the adjacent main street were small in regions without linear trees and shrub rows during both the weekdays and weekend. On the other hand, the areas with linear trees and shrub rows were found to have significantly higher concentrations of PM compared to the roadway. In particular, sections with linear trees and shrub rows had higher PM levels both on roads and in adjacent open space, indicating that the composition of linear trees and shrub rows increased the concentration of PM in the off-street open space in areas with wide space between the roadway and building. The impact was more significant in the open space than the roadway. This phenomenon can be explained by the fact that PM generated by vehicles flows through the roadside shrubs by rapid wind flow but does not disperse widely in the pedestrian paths where the wind flow was reduced. In this study, we found that the roadside tree and shrub walls slowed the flow of wind, causing vehicle-emitted PM to accumulate if a wide open space was created between the road and building, resulting in higher concentration of PM in the open space. We confirmed that the distance between the road and building was a critical factor for constructing linear trees and shrub rows to reduce PM generated by vehicle traffic.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.3-12
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• 2012

The slowdown of private building industry resulted in growth of remodeling market as a way to improve energy performance. Remodeling is considered more cost-effective and eco-friendly approach for energy efficient building than new construction. Since 2008, Seoul has promoted Building Retrofit Project (BRP) preponderantly to attract energy-saving renovation by supporting building owners to switch building system into energy-saving system when they remodel their old buildings. According to 2012 press release, 254 Private sectors participated in this green building project and annually reduced 41000ton of greenhouse gas emission, 14000TOE, which also result in 7.5 billion won energy cost savings per year. The paper focuses on the building envelope remodeling as a way to improve energy efficiency. Different components of the building envelope such as wall insulation, window, and shading, were applied to the baseline model and the comparison was analyzed to come up with the ideal solution. This study only assesses the building envelope as to suggest the way to redesign the better energy performing building. Offering solution focusing on the architectural feature is essential because it will provide basic information and standard when remodeling a building for energy efficiency, especially, for the nonresidential buildings used as rental offices.

• Land and Housing Review
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• v.15 no.1
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• pp.147-156
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• 2024

This study aims to reduce CO₂ generated during the manufacturing process by using limestone (CaCO₃), a carbonate mineral used in the production of cement clinker, as a decarbonated raw material that does not contain CO₂. Among various industrial by-products, we attempted to use cement paste attached to waste concrete. In general, limestone for cement must have a CaCO₃ content of at least 80% (CaO, 44% or more) to ensure the quality of cement clinker. However, the CaO content of waste concrete fine powder is about 20% on average, so in order to use it as a cement clinker raw material, the CaO content must be increased to more than 35%. Therefore, by using the difference in hardness of the mineral composition of waste concrete fine powder to selectively crush CaO type minerals with relatively low hardness, classify and sieve, the CaO content can be increased by more than 35%. Accordingly, in this study, we experimentally and statistically reviewed and analyzed the optimal conditions for efficiently separating CaO and SiO₂ and other components by selectively pulverizing minerals containing relatively low CaO through a grinding process. As a result of the optimal grinding conditions experiment, it was found that the optimal conditions were a grinding time of less than 5 minutes, a type of material to be crushed of 30 mm, and an amount of material to be crushed of 1.0 or more. However, it is judged that it is necessary to review pulverized materials of mixed particle sizes rather than pulverized products of single particle size.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.6
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• pp.66-72
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• 2010

Seoul City planned "Dreamland" to be in harmony with the huge woods and park. It is located in the life zone in the northern region of Seoul as part of an extensive park development plan that the municipal government has promoted. The space configuration technique of the aesthetics of "Empty" rather than "Full" gives the potentiality to cope with the uncertain changes in the city. Furthermore, the traditional element of the mountain landscape of Seoul was introduced and appropriated as the axis of the landscape for landscape configuration. In that configuration, the images of tree, sky, wind, water and soil are elegantly unfolded like a landscape painting. The purpose was to create a dominant landmark in the city landscape with the figures of Korean mountains and hills which were differentiated from architectural landmarks in the western cities by making nature, which was excluded from the urbanization plans up to now, an important subject for consideration. As a result, this study madethe space in a park including existing yards and streets in a city have the traditional hierarchy by applying the facility arrangement technique and elements extracted from Korean space types and traditional landscape concepts. Moreover, the North Seoul Dream Forest was designed by pursuing diversity and potentiality in the experience of space using a large open field in a city.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.265-272
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• 2011

Even though concrete is the most important material for building structures, its intrinsic gray color degrades urban esthetics. In order to improve this problem, coloring methods of mixing pigment in concrete batch and painting the surface of concrete surface have been tried. However, applications of the coloring methods in construction field are difficult due to high cost and low durability. Recently, acid stain agent is emerging as a new coloring method for concrete. It is able to apply a remarkably thin colored layer on a concrete surface from chemical reaction between acid and alkaline solutions. This study has examined the changes and variations of the surface layer of mortar specimen from chemical reaction of acid stained agents. The colors were changed into natural irregular stains according to aging. After the staining, no shape change was found from visible inspections. Microstructure of the colored surface applied with acid stained agent was much rougher than that of original mortar. When the colored layer was compared to original surface, crystals of hydrate such as $Ca(OH)_2$ and C-S-H gel were observed. Surface hardness was same or slightly higher in the colored layer. The value of pH was reduced by approximately 10%, weight contents of elements such as Ca, Si, and Al were low. In the chemical composition of the colored layer, the non-cement based elements of Mn, Cr, and Cu increased. Also, Fe and alkali elements of K and Na increased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.229-235
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• 2019

A floating photovoltaic generation system is a new concept that combines existing photovoltaic generation technology with floating technology. This is installed in the water not on conventional land and a building. The system is designed as a unit module type that can be connected to other modules according to the power generation capacity, thereby forming a large-scale power generation facility. As a renewable energy source, it is composed of a floating structure, mooring device, photovoltaic power generation facility, and underwater cable. Because this system is installed outdoors, the effect of the wind load on the structure is very large. In this study, the wind loads most affected on the floating photovoltaic generation structure were obtained by computational fluid dynamic analysis. The flow characteristics and wind loads were analyzed for a range of wind orientations and angles of inclination. The analysis showed the position and magnitude of the maximum wind load to the wind direction and the flow characteristics around the solar panel and floating system. The wind load increased with increasing angle of inclination of the panel to the ground.

• Resources Recycling
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• v.28 no.6
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• pp.64-72
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• 2019

Fly ash has different chemical composition depending on the type and quality of flaming coal. Fly ash is classified according to carbon content and particle size. Waste glass powder is manufactured by crushing glass. Exterior Insulation Finish System (EIFS) is generally applied by using poly-styrene foam which is economical and has excellent thermal insulation performance. However, poly-styrene foam has excellent insulation performance, but it is vulnerable to fire, which is becoming a serious problem. In this study, using a fly ash and waste glass powder to produce a finishing mortar at high temperatures. Also, High temperature strength and flame retardant properties were tested according to the cover thickness. From the test result, finishing mortar prepared using fly ash and waste glass powder is due to the improved heat resistance by alkali-activated bonding. However, since the strength decreases at high temperatures, it is necessary to select an appropriate mixing proportion.

• Journal of the Korean GEO-environmental Society
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• v.11 no.4
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• pp.51-59
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• 2010

This article is a case study for the example of the foundation design, in the project area of the silty sand layer that is spread shallowly with loose status, to make the site for a structure and build it up. The site is located on the dredged and reclaimed land in Gun-San and In-Cheon that is formed the silty sand layer with loose status range around 10 meters underground level, the solid ground for the lower pile is shown around 20 meters underground level. Therefore, this area has to be done by ground improvement when applying for the shallow method of foundation. Dynamic compaction method considering the conditions of the design loads in each zone has to be decided through comparative review on the method of foundations and pilot field test was conducted, and drilling investigation and plate bearing test were achieved as well. The analysis results of the tests prove that stability against bearing capacity was acquired by ground improvement effect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.1-9
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• 2018

In this paper, we propose a film-type dual-band frequency selective structure for improving the wireless communication environment in a building. The proposed frequency-selective structure is a miniaturized structure that can control the resonant frequencies of 2.4 GHz and 5 GHz dual band through simple design parameters. We fabricated the frequency-selective surface by screen printing using conductive ink on a thin transparent film and confirmed its performance by measurement. We analyzed the attenuation performance of the unnecessary signal from the outside when the frequency-selective structure designed using the software to analyze the propagation environment performance is applied to the building. To verify the analytical results, the signal strength of the indoor environment was measured by applying the frequency-selective film fabricated on the inner wall of the actual building. The measurement results show that the dual-band frequency-selective film has 29.4 dB and 15.94 dB attenuation performance in the 2.4 GHz and 5 GHz, respectively.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.13 no.1
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• pp.39-46
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• 2007

종고대도현재하단전재건신양생방면점착흔중요위치. 의가(醫家), 도가(道家), 불가등위료보지건강타문주료흔다노력화각식적연구. 하단전시태아재모친복중생활적지방(下丹田是胎兒在母親腹中生活的地方), 시정자재부친체내생장적중요부위시생명성장적지방(是精子在父親體內生長的重要部位是生命成長的地方), 위료보유지건강적영혼화육체취요단련단전보지단전기중최보편적방법취시단전호흡화수기(爲了保維持健康的靈魂和肉體就要鍛鍊丹田保持丹田其中最普遍的方法就是丹田呼吸和手技)(침구(鍼灸), 약(藥), 안마(按摩)), 본고취시통과수기유지건강적단전소주적고찰(本告就是通過手技維持健康的丹田所做的考察). 한의학설(韓醫學說);(종동양사상주기초(從東洋思想做基礎))치인체질병유음양설(治人體疾病有陰陽說), 오행설등동양문화적근원음양설시포괄인간자연계적세계만물(五行說等東洋文化的根源陰陽說是包括人間自然界的世界萬物), 음화양적상대성(陰和陽的相對性), 상보성(相補性), 상련성등(相連性等) 원리주적관찰(原理做的觀察), 오행설시목(五行說是木), 화(火), 토(土), 금(金), 수자연계적삼라만상오류군적상생(水自然界的森羅萬象五類群的相生), 상극(相剋), 상화사득만물질서조율(相和使得萬物秩序調律), 인체시삼라만상(人體是森羅萬象), 우주중적소우주(宇宙中的小宇宙), 산화계곡(山和溪谷), 천화강해(川和江海), 동식물(動植物), 생활도구(生活道具), 건축물(建築物), 천체화무의등조성료인체구조자연화생명적조화중한의학시용침술화약재치료료인적질병(天體和巫醫等組成了人體構造自然和生命的造化中韓醫學是用鍼術和藥材治療了人的疾病). 저양조화유지료신체건강, 여과파배료저종조화상호보충적관계취회출현이상, 취회질인병기질병(就會疾引病起疾病), 소이위료유지신체적조화취요호호적이해신체적구성(所以爲了維持身體的調和就要好好的理解身體的構成), 관리호신체적각부분(管理好身體的各部分). 저시논문규명적취시신체내양생최중요적지방시단전, 하단전적구조이해지후취회명백유지신체조화적경혈적관계(下丹田的構造理解之後就會明白維持身體調和的經穴的關係).