• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.387-391
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• 2007

A proper selection of formwork greatly affects project success in tall building construction. The tall building construction, however, has not been selected properly using the characteristics by formwork and demands the comprehensive consideration of cost, duration, quality, safety, and environment. Therefore, this study compares and analyzes the application by formwork of five aspects. In order to perform an analysis, the questionnaire was performed to research the priority order of management as determining formwork and application by formwork of tall building construction engineers. This study is expected to help reasonable selection of formwork.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.6
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• pp.242-252
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• 2018

It is well known that an Oscillating Water Column Wave Energy Converter (OWC-WEC) is one of the most efficient wave absorber equipment. This device transforms the vertical motion of water column in the air chamber into the air flow velocity and produces electricity from the driving force of turbine as represented by the Wells turbine. Therefore, in order to obtain high electric energy, it is necessary to amplify the water surface vibration by inducing resonance of the piston mode in the water surface fluctuation in the air chamber. In this study, a new type of OWC-WEC with a seawater channel is used, and the wave deformation by the structure, water surface fluctuation in the air chamber, air outflow velocity from the nozzle and seawater flow velocity in the seawater channel are evaluated by numerical analysis in detail. The numerical analysis model uses open CFD code OLAFLOW model based on multi-phase analysis technique of Navier-Stokes solver. To validate model, numerical results and existing experimental results are compared and discussed. It is revealed within the scope of this study that the air flow velocity at nozzle increases as the Ursell number becomes larger, and the air velocity that flows out from the inside of the air chamber is larger than the velocity of incoming air into the air chamber.

• Korean Journal of Construction Engineering and Management
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• v.9 no.5
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• pp.159-167
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• 2008

This study provides a effective approach to the construction management problem with the limited number or amount of available resources using the analytic hierarchy process. Construction management is a series of decision making processes for planning and controling of cost, time and quality as main objectives in construction works. When several activities need the limited same resource at the same time, it is very hard to decide the priority of the activities in the real situations. For that the scientific decision making method and procedure for resource allocation are required. This study solves the resource allocation problem by dealing with the decision making problem which the activities are distributed to multiple projects and under multiple criteria. The analytic hierarchy process is a method devised to solve complex multi-criteria decision problems. The result shows that this study can be effectively used to make decisions in situations involving multiple objectives by evaluating the prioritized ranking and degree of the activity alternatives based on the overall preferences.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.363-369
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• 2008

Change is inevitable and is a reality of construction projects. Change adjustment includes the cost associated with materials, labor, etc. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. What is needed is a reliable method to identify and quantify the loss of productivity caused by cumulative impact of change orders. This study survey the change orders data in domestic area for public construction and analyze to quantify change order impact. This study developed concepts of "%CO", "%Delta", "%T" to capture change order effect on project and search the relationships between them. Finally, this study find strong relationship between change order and loss.

• Journal of Navigation and Port Research
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• v.33 no.3
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• pp.227-233
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• 2009

This experimental study has been carried out to investigate the reduction in side friction of open caisson using air-jet method. For this study, the large size caisson having air-pockets was used. This caisson was used as substructure of bridge. By using air-jet method, settlement time was decreased and even settlement was reached to the depth which conventional methods could not be. We found that the side resistance decreases to less then half the expected value. In addition to these merits, the air-jet method can result in self-weight settlement without applying additional load. Also the open caisson damage caused by blasting can be prevented with this method.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.555-561
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• 2015

The construction industry is a labor-oriented and quality, cost, and schedule performance is effected by technicians. However, the construction industry have faced a labor shortage problem. Therefore, technician graying and no new workers inflow cause labor shortage and decline of worker's skill level. The utilization of foreign technicians instead of domestic technicians has been increased in the construction industry. This paper performed questionnaire survey for 43 managers on 14 project fields to determine the current status and problems of construction technicians and to propose a improvement plan. As a result, most foreign technicians are carpenters and iron workers, but the skill levels are generally lower than domestics. The major problems for foreign technicians are communication and non-skilled. Then, labor productivity and accident rates of foreign technicians are higher than domestics. This paper proposes that skill training programs, language lessons, and multi-cultural programs are effective to improve foreign workers' problems.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.545-550
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• 2001

Domestic construction industry has faced with many problems in productivity, quality, safety and skilled-labor availability because of the national economic depression, insufficient supply of skilled labors and so on. There is a growing need for improving productivity and quality, and savings in cost. In the case of advanced countries, they have made a number of research efforts to solve these problems with construction automation and robotics. Recently, there are growing interests in construction automation and robotics but such interests have not been further increased due to the difficulties in gathering or accessing valuable information on the research and development of construction automation and robotics. The main purpose of this study is to provide a web-based research database and decision support system for an effective research and development of automated construction system and robots. It is expected that this system would be able to provide a framework for the successful research, development and implementation of the construction automation and robotics in domestic construction industry

• Korean Journal of Construction Engineering and Management
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• v.23 no.5
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• pp.34-42
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• 2022

Construction site layout is attracting attention as efficient use of construction site space greatly affects the duration and cost of the overall construction. Therefore, there are many studies that automate and optimize construction site layout planning. However, the usability of construction site, which consists of goal variables of the studies, has still been unknown. Therefore, the authors present the evaluation criteria for usability of construction site layout and evaluate the usability of domestic construction sites through user survey. Furthermore, the difference in usability between construction site managers and construction site workers was confirmed. As a result of the survey, domestic construction site layout had a low effectiveness and had the lowest score in the environment category. In addition, construction site workers scored lower overall than construction site managers. Through such usability evaluation results, it contributed to the construction site layout theory by assessing current construction site layout practice and suggesting an improvement direction for automating site layout planning.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.379-384
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• 2002

A road construction project needs a large scale of investment and tine. In this study, we will review some elements of feasibility analysis and derive points of the existing analyses. And we make some suggestions to improve the existing methods. We propose a 'A Feasibility Information System' for road construction projects. The system will be useful to make a feasibility study for road construction project and help us to predict risks in process of the projects.

• Information and Communications Magazine
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• v.30 no.10
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• pp.25-31
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• 2013

본고에서는 건설기술과 IT기술이 융합된 건설IT융합기술에서 스마트 빌딩과 관련하여 안전, 건강, 편의, 에너지를 위한 기술들로 분류하여 사례와 함께 서술한다. 고층 빌딩의 안전성을 위한 건축 구조물 건전도 모니터링 기술, 빌딩 실내 또는 지하 주차장에서 쾌적한 공기 환경을 유지하기 위한 스마트 환기제어 시스템 기술, 빌딩 정보의 체계적인 데이터 관리를 위한 빌딩정보모델링 기반의 센서와 영상 인터페이스, 스마트 빌딩 네트워크 관리 시스템에 관하여 소개한다. 또한, 에너지 절감을 위한 빌딩 에너지 관리 시스템에 관하여 냉난방, 조명, 환기설비, 전력모니터링 관련 기술에 대하여 설명한다. 이러한 기술들을 적용한 스마트 빌딩은 유무선통신, 스마트디바이스와 같은 IT기술을 건축공학 및 빌딩자동제어, 설비 기술에 적용하여 빌딩 사용자에게는 안전 및 최적 환경을 제공하고 빌딩 소유주나 관리자에게는 관리비용 절감, 관리 편의, 빌딩가치 상승 등을 제공할 수 있다.