• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.119-131
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• 2007

Design build (DB) is a construction project delivery system which has become one of the favored ones and the growth of DB by the public agencies has been steadily increasing. DB can be viewed as an evolutionary project delivery system, since DB project team members collaborate on work with each other, keep seeking cost effective and innovative alternatives that meet the construction needs of the project. Thus DB outperformed others in delivery speed, cost saving, and turnover quality. In Korea, DB projects likewise have steadily increased that it is needed to analyze characteristics of DB delivery system in Korea. For that purpose, this research would offer an analysis of characteristics of DB delivery system in Korea using system dynamics model with investigating the public market trend, comparing DB performance to DBB, and analyzing questionnaire survey.

• Korean Journal of Construction Engineering and Management
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• v.4 no.1 s.13
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• pp.90-96
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• 2003

The purpose of this study is to present an improvement building construction process by using prefabricated materials. The current slab form work has waste factor by unnecessary process and not complete integration with the finishing process. Therefore the study used value stream analysis methodology for effective improvement of slab form work process. The main contents of the study are as follows; 1) Non-value adding activities were found at existing slab form work process by current state mapping(CSM) 2) Future state mapping(FSM) suggest process Integration to slab form work. 3) Slab form work is analyzed reduction time-cost by prefabricated material. The study recommends that, as a future research, development of tool and technique for the non-value adding activities are eliminated in building construction and application of prefabricated material should be increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.325-325
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• 2017

빗물펌프장은 도시지역 저지대의 우수를 강제로 배출하여 제내지의 치수안전도를 향상시키기 위한 방재시설이다. 변화하는 기상조건에 맞추어 침수취약지역의 치수안전도를 유지 또는 향상시키기 위해서는 빗물펌프장 설계시 목표한 치수성능을 지속적으로 구현할 필요가 있다. 그러나, 펌프시설의 고속운전, 변화하는 펌프운영조건 등의 영향으로 펌프의 성능은 지속적으로 저하된다. 이와 같은 펌프성능의 주요원인은 펌프운영시 발생하는 공기연행이 주요 원인중 하나이다. 흡수정 설계단계에서는 와류에 의한 공기연행을 제어하기 위하여 흡입관경, 흡수정 벽면으로부터의 이격거리 등의 설계요소를 반영하고 있지만, 도심지역의 제한적인 공간특성으로 인하여 설계기준치를 만족하지 못하는 경우가 발생하게 된다. 설계시 흡수정 내에 형성되는 와류를 억제하기 위하여 흡수정의 벽면 모서리를 완만하게 시공하거나, 흡수정 내에 날개벽 또는 별도의 시설을 설치하는 방법을 채택하고 있다. 그러나, 이와 같은 와류방지시설은 고정된 설계조건에 대하여 성능구현이 가능하지만, 홍수시 흡수정 내의 흐름은 하천의 수위 및 유입되는 유량에 의하여 시시각각 변화하게 된다. 이와 같은 운영조건의 변화에 대응할 수 있는 방법을 제시하기 위하여 본 연구에서는 수면에 부유식 와류방지장치를 설치하고 이에 대한 성능을 3차원 수치모의를 통하여 재현한 후 정량적으로 분석하였다. 부유식 와류방지장치에 대한 성능검토결과, 다양한 운영조건에서도 부유식 와류방지장치가 유효한 와류저감효과를 구현하고 있는 것을 확인하였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.367-375
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• 2022

In this study, the characteristics of recycled aggregate concrete according to the mixing ratio of recycled fine aggregate were analyzed by design strength to explore its use in the production of ready-mixed concrete. The results show that, depending on the ratio of recycled aggregate, the compressive strength is similar to that of normal concrete and does not deteriorate. Therefore, it is possible to achieve a strength similar to the target design strength. Furthermore, if the ratio of recycled fine aggregate for concrete is up to 25 % of the total aggregate amount (50 % of the to-tal fine aggregate), slump does not cause problems. Our findings show that the higher the de-sign standard strength, the greater the amount of powder, and management of slump reduction, unit quantity, and performance system is necessary. The obtained results show that recycled ag-gregate can be used for the production of ready-mixed concrete after adjusting its mixing ratio and concrete mix proportions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.6
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• pp.625-635
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• 2013

Although the TBM method is mainly adopted in overseas market including the Europe, etc, the method scarcely adopted in domestic market. For highly enhancing applications of the TBM method for railway, It is needed to select the optimal cross-section considering design elements of civil engineering and aerodynamic effects. Also, it is needed to establish plan of proper section as well as reviewing aerodynamic effects and consideration about civil engineering elements such as length of tunnel, speed of railway, height of whole lines and size of utility tunnel, etc. Even though it should be recently considered high-speed railway tunnels and required to be standard establishments in aerodynamic reviews, it is being applied to be criteria of inconsistent pneumatic analysis owing to be not related with domestic standards. In this study, therefore, we are willing to establishment of domestic and foreign aerodynamic standards and investigate correlation between optimal cross-section and aerodynamic effects of TBM railway tunnels.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.369-380
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• 2023

The incorporation of innovative technology systems into domestic construction practices has catalyzed an organic evolution of the industry, significantly enhancing the level of domestic construction technology and intensifying competitiveness. In particular, the on-site implementation of these groundbreaking construction technologies has proven effective in diminishing construction costs and accelerating project timelines. Nevertheless, despite a period of 33 years since the inception of this new construction technology system, both the volume of designated construction technologies and their practical application on construction sites remain static. As a consequence, this study introduces a strategic plan to dissect and overcome the barriers faced in the adoption of new construction technology across a multitude of sectors. The chief outcomes encompass the inception of a new construction technology utilization surveillance system, an assessment of distinct technologies, refinement of the post-evaluation system, and the creation of a new technology market system. This systematic enhancement is anticipated to foster the practical application of new construction technologies within the industry.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.253-262
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• 2018

Oscillating Water Column (OWC) Wave Energy Converters (WEC) harness electricity through a Power-Take-Off (PTO) system from the induced-airflow by seawater oscillating inside a chamber. In general, an air chamber with a relatively small cross-sectional area is required compared to seawater chamber to obtain high-velocity air in the PTO system, and in order to simulate an accurate air flow rate in the air chamber, a three-dimensional study is required. In this study, the dynamic response of OWC-WEC that is equipped with the channel of seawater exchange for the case of irregular waves has been numerically studied. The open source CFD software, OLAFLOW for the simulation of wave dynamics to the openFOAM and FOAM-extend communities, was used to simulate the interaction between the device and irregular waves. Based on the numerical simulation results, we discussed the fluctuation characteristics of three dimensional air flow in the air-chamber, wave deformation around the structure and the seawater flow inside the channel of seawater exchange. The numerical results the maximum air flow velocity in the air-chamber increases as the Ursell value of the significant wave increases, and the velocity of airflow flowing out from the inside of air chamber to the outside is greater than the speed of flowing into the air chamber from the outside.

• Journal of the KSME
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• v.32 no.3
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• pp.230-240
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• 1992

이 글에서는 국내 특성에 적합한 초고층아파트 설비시스템의 설계기법 확립 및 설비시스템의 최적모델을 정립함으로써 초고층 아파트 설비시스템의 효율향상은 물론 공사비절감, 품질향상, 공기단축 등의 효과를 통해 양질의 저렴한 주택의 기술개발에 기여하고 건설업의 대외개방에 대비한 국제경쟁력을 고취시키는데 필요한 초고층아파트 수직통로내의 열유동현상, 배관부식 방지기법 및 설비시스템의 구성요소별 설계방안 등에 대해 소개하고자 한다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.246-249
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• 2004

While the recovery of local construction industry is picking up steam, and the number of the employed in the construction industry is on the increase, workforce supply is out of balance in its quality as well as quantity, and with economic crisis facing the country, construction and recruitment methods are in transition. In addition, rising demand in skilled workforce and a workforce in short supply have expedited wage rises and have brought broad effects on construction including productivity and construction time. Such imbalance in construction workforce supply also causes various structural changes by category. This research compares and analyzes data on annual wages of construction workforce, analyzes the state of construction workforce supply, understands recruitment structure in accordance with workforce supply conditions, and looks over characteristic changes in recruitment structure. With reflections drawn from these, this paper suggests responsive measures to future construction circumstances - changes to wages of construction workforce - as well as prospects of future construction workforce supply and measures designed for stable medium and long-term workforce supply.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.11a
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• pp.87-91
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• 2005

최근 언론매체나 인터넷을 통해 자주 접하게 되는 용어 중 하나가 '유비쿼터스'이다. 각종 서비스, 도시건설, 아파트 등 다양한 대상에 'Ubiquitous' 또는 'U-'라는 수식어를 붙이는 것을 흔히 접할 수 있으며, 마치 매우 편리한 환경을 상징하는 키워드처럼 인식되고 있다. 이와 관련하여 현재 우리나라에서는 정보화도시(U-City 또는 디지털시티라고도 함) 건설 추진 및 그에 대한 논의가 활기를 띠고 있다. 이를 통한다면 우리나라는 건설 및 IT강국이라는 핵심역량을 바탕으로 내수경기 부양뿐만 아니라 지역 간 불균형을 해소할 수 있고, 국내성공 사례로 글로벌 시장개척을 위할 수 있으며 넓게는 동북아 비즈니스 허브구축의 발판이 마련될 수 있겠다. 이밖에도 정보화도시(U-City)건설은 많은 산업화의 가치를 가지고 있기 때문에 정부와 지자체, 또한 기업체에서 기술 개발 및 시범사업에 박차를 가하고 있다. 그러나 새로운 도시유형으로서 정보화도시(U-City)의 개념은 아직까지 제도적으로 정립되어 있지 않을 뿐만 아니라 도시건설 시 어떤 특별한 유인책도 마련되어 있지 않다. 그리하여 지방자치단체, 공기업 등 추진주체마다 전개되는 양상이 다르며 이에 수반되는 다양한 문제가 발생한다. 따라서 정보화도시(U-City)의 성공을 위해서는 글로벌 인재들이 유인할 수 있는 매력을 갖추어야 하며 사회적 투자를 지속시킬 수 있는 효과적 방안이 필요하겠고 핵심기술과 이의 활용방안이 마련되어야겠다. 그러나 무엇보다도 정보화도시 건설관련 법, 제도, 사회시스템 정비가 선행되어야하겠다.