• KIEAE Journal
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• 제8권3호
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• pp.13-18
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• 2008

Recently it is urgent issue in every department that problem from environmental disruption such as global warming. As the case of streetscape works essentially at city scenery, it is inevitable that changing from present view, which centers facilities and buildings, to environmental harmonic scenery. This study plans climate adjusting ability and improvement of thermal efficiency by putting ecological elements to buildings on a street which are essential factors of streetscape. Ultimately, this not only makes a pleasant environment but also revives being withered earth. Street-environment on eco-scape will take a part in designing sustainable city. This study acquires the way how buildings on a street get applied ecological elements as following. Roof level part : the greening surface of the rooftop(included plant box type), the greening roof as a type of pergola, the greening surface of the middle floor rooftop(included plant box type). Elevation part : climbing type, downfall type, espalier, flower bed in balcony type, wall-installing type, water wall type, other design types. Ground level part : paving the whole surface with permeability, paving the gap with permeability, plant box type, ground plant type, waterside zone, wetland, fence greening type, terrace greening type, retaining wall greening type.

• KSTLE International Journal
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• 제3권2호
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• pp.79-83
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• 2002

Sealing an oil-air mixture plays important roles to have an enhanced lubrication for high speed spindle. High speed spindle requires non-contact type of sealing mechanism. Current work emphases on the investigation of the air jet effect on the protective collar type labyrinth seal. To improve the sealing capability of conventional labyrinth seal, air jet was injected against through the leakage flow, It has a combined geometry of a protective collar type and an air jet type. Both of a numerical analysis by CFD (Computational Fluid Dynamics) and experimental measurements are carried out to verify sealing improvement The sealing effects of the leakage clearance and the air jet magnitude are studied in various parameters. The results of pressure drop in the experiment match reasonably to those of the simulation by introducing a flow coefficient Effect of sealing improvement is explained as decreasing of leakage clearance by air jetting. Thus, sealing effect is improved by amount of air jetting even though clearance becomes larger.

• 한국건축시공학회지
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• 제13권3호
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• pp.227-234
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• 2013

본 연구에서는 3종 조강시멘트에 비해 경제성을 개선하고, 1종 보통포틀랜드시멘트에 비해 조강성능을 개선한 조기강도 개선형 시멘트를 사용한 조강콘크리트의 양생온도 및 물시멘트비에 따른 굳지 않은 콘크리트 특성 및 조기강도 발현 특성을 검토함으로써, 이를 활용한 조강콘크리트의 실용화를 위한 기초자료를 제시하고자 하였다.

• KIEAE Journal
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• 제13권4호
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• pp.27-32
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• 2013

This study focus on shaft box facade, special form of box window construction. It consists of a system of box window with continuous vertical shafts that extend over a number of stories to create a stack effect. The subject building was decided by analyzing various types of exiting apartments. Shaft box type balcony was devised by setting up shaft space at a part of balcony. Air flow and indoor air temperature were simulated, performance of shaft box type balcony was compared with existing types using VE computer simulation program. Research consequence can be summarized as follow: 1) In the case of existing types, the change of window opening rate has only a little effect on the improvement of indoor temperature. But, air flow rate increased two times in the case that changed opening rate 20% to 40% 2) In the case of existing types, the growth of air flow rate has little effect on the improvement of indoor temperature. But, shaft box type represented the remarkable effect on the improvement of indoor temperature as well as the growth of air flow rate.

• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.18-21
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• 2013

$SiO_2$ layer grown by rapid thermal oxidation and $SiN_x$ layer were used for passivating the surface of n-type silicon solar cell, instead of only $SiN_x$ layer generally used in photovoltaic industry. The rapid thermal oxidation provides the reduction of processing time and avoids bulk life time degradation during the processing. Improvement of 30 mV in Voc and $2.7mA/cm^2$ in Jsc was obtained by applying these two layers. This improvement led to fabrication of a large area ($239cm^2$) n-type solar cell with 17.34% efficiency. Internal quantum efficiency measurement indicates that the improvement comes from the front side passivation, but not the rear side, by using $SiO_2/SiN_x$ stack.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제17권4호
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• pp.39-47
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• 2011

Population ageing and the disabled population is increasing. so disabled population and elderly people in the physical environment for Barrier-Free recently has been getting attention. according to a recent welfare paradigm shift of life support promoting for the housing remodeling. but basic remodeling made of simple living environment improvement and facilities installation for the type of disability customised housing remodeling. efficient housing remodeling plan for remodeling before and after through change the safety accidents occurred ratio. living environment for the improvement of housing and reconstruction for the benefit of comprehensively considering for disability subject in Indoor living type and the type of disability, housing type etc. and personalize house was remodeling for corresponding each space problem for identify obstacles and living types. as a result satisfaction changes & safety accident rate changes as follow. first, have complained that there was a in to residents environment furniture for reconstruction of the former housing remodeling needs survey. 80.2% of total for the percentage of households with high needs remodeling. second, The survey did not meet the 29 furniture as after the construction for died about recipient & up sticks & long absence. this leave out after the safety accident Corporation about 101 housing in the 88% of households did not happen. as a result, the lower the ratio of safety accidents occurring very revealed. third, grasp the meaning for indoor living type. showed that each approach(83%), front porch(90%), kitchen, living room(91%), bedroom(93%), toilet(92%) for each space remodeling satisfaction flow through customized housing remodeling.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.79-88
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• 1993

The purpose of this study is to provide a firm base for the quality improvement of high strength concrete and the development of ultra high strength concrete as well as enviromental con-servation and utilization of byproducts from industrial processing such as Fly ash and Silica fume. A comprehensive experimental study was performed to investigate the effects on the quality improvement of high strength concrete using mineral admixtures. As results, 400~500kg/$\textrm{cm}^2$ compressive strength and excellent flowability can be obtained if fly ash is replaced with cement in the range of 305. In case of using powder type silica fume, 600~700 kg/$\textrm{cm}^2$ compressive strength is showed and 600~800kg/$\textrm{cm}^2$ compressive strength cam be obtained with liquid type silica fume. But it is necessary to increase dosage of high range water reducer for flowability using powder type silica fume. Especially, higher strength concrete cam be obtained when maximum size of coarse aggregate is lower than 25mm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.855-860
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• 2001

In this study, the improvement work to reduce the steering wheel vibration of a forklift truck is performed. The forklift truck newly developed possesses a trans-axle type power train to achieve a compact and low-price design. The forklift truck is directly subjected to a high-level engine vibration through hard mounted trans-axle housing. The engine vibration shakes the whole system of the forklift truck, and then a high level local vibration of steering wheel could not be avoided. As the results, the vibration source and path mechanisms are experimentally identified and then an improvement design is proposed to minimize the steering wheel vibration.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.120-121
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• 2017

Generally, slump of plain concrete slab is about 120~150mm and slump loss is easy to occur. So, water is added to concrete because this method is convenient for Placing. In order to solve this problem, performance evaluation of concrete using improvement type PC admixture was carried out. Target slump is 210mm and compressive strength is 18MPa. As a result, slump reference value was satisfied 60 minutes after placing and 7-day compressive strength was 21~25MPa.

• 유공압시스템학회논문집
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• 제6권1호
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• pp.17-24
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• 2009

The performance improvement of a small-size integrated-type fully hydraulic breaker is studied in this paper. Mathematical modeling of the breaker is established and verified by experiment. Through sensitivity analysis using AMESim, the key design parameters are selected and nearly optimized to maximize the impact energy as well as to improve the dynamic characteristics such as the piston upper chamber pressure, piston and valve displacements. As a result, the impact energy, blows per minute(bpm) and output power are increased by 52.9%, 1%, and 55.6%, respectively compared with the current design. The dynamic characteristics of the piston upper chamber pressure, piston and valve displacements are also improved by the design change.