• International conference on construction engineering and project management
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• 2005.10a
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• pp.1208-1211
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• 2005

The design phase has a great influence on the success of subsequent phases in the project which can be connected with the success of the overall project. Several studies have focused on the effective design management. However, it is too complicated and difficult to manage the design process for the reason that it has a lot of participants and design information and consists of thousands of decisions by an architect alone. Accordingly, it is the main issue for the success of the project how well the design phase be organized and managed. In recent, even in domestic, the importance of design phase has begun to be referred in the conferences. Lean Construction also has a close look at those issues and makes ready to apply specific management methods, called to Lean Design & Construction. Managers can consider a variety of uncertainties to be under control through making the overall process effectively from the early stage. By establishing the efficient process from the design phase before the construction phase, managers can result in a desirable productivity. The aim of this study is to bring the concept (Lean Design & Construction) in domestic design circumstances and verifies the possibility how to apply the concept to the design phase.

• International Journal of High-Rise Buildings
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• v.11 no.2
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• pp.115-124
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• 2022

Welding is a significant part of the construction industry. Since most high-rise building construction structures rely on a robust metal frame welded together, welding defect can damage welded structures and is critical to safety and quality. Despite its importance and heavy usage in construction, the labor shortage of welders has been a continuous challenge to the construction industry. To deal with the labor shortage, the ultimate goal of this study is to design and develop an automated robotic welding system composed of a welding machine, unmanned ground vehicle (UGV), robotic arm, and visual sensors. This paper proposes and focuses on automated weaving using the robotic arm. For automated welding operation, a microcontroller is used to control the switch and is added to a welding torch by physically modifying the hardware. Varying weave patterns are mathematically programmed. The automated weaving is tested using a brush pen and a ballpoint pen to clearly see the patterns and detect any changes in vertical forces by the arm during weaving. The results show that the weave patterns have sufficiently high consistency and precision to be used in the actual welding. Lastly, actual welding was performed, and the results are presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.200-201
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• 2021

According to the dispute cases filed for claiming the collective defect repair fees, inter-layer concrete joints turned out to be the most frequently disputed item. For this reason, this study selects the inter-layer concrete joints to further analyze the primary causes and details of each dispute case. From the results of this study, three primary causes of the disputes are found, which are 1) the absence of standard specifications for construction quality control and management after construction; 2) the absence of established standards for repair when construction defects are found. In order to prevent construction defects in inter-layer concrete joints, this study provides three suggestions including 1) the current standard specifications for inter-layer concrete joints should be further specified by the Ministry of Land, Infrastructure and Transport; 2) a construction defect should be judged according to the compliance to the standard specifications; and 3) a clear and institutional protocol needs to be established for defect repair in cases that new public apartment houses have been judged to have defects.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.344-348
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• 2015

The image data of the web camera is used to identify the construction status of the site in a remote office and it can be used for safety management. This study develops a construction schedule simulation system based on the active nD object linked with real image data of web camera from the construction site. The progress control method by 4D object uses a method that the progress of each activity is represented with different colors by progress status. Since this method is still based on a virtual reality object, it is less realistic description for practical engineers. Therefore, in order to take advantage of BIM more realistic, the real image of actual construction status and 4D object of planned schedule in a data date should be compared in a screen simultaneously. Those methodologies and developed system are verified in a case project where a web camera is installed for the verification of the system.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1104-1111
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• 2024

In recent years, the development of digital design methods and structural analysis has made it possible to design complex building shapes. However, the construction of such buildings requires advanced knowledge of production, interaction with actual craftsmen, and verification of construction methods through mock-ups. Despite this, however, design education in Japanese universities is often limited to proposals at the predesign and schematic design stages, and students have few opportunities to study the design development and construction stages. However, in recent years, computer numerical control (CNC) machine tools have become relatively inexpensive and can be handled easily, even by beginners. Therefore, practical training programs intended to familiarize students with manufacturing techniques using such machines are becoming increasingly popular at Japanese universities. This paper reports on the content of a practical training program intended to provide students with practical experience from production to design in the field of manufacturing by using CNC machine tools and other digital fabrication equipment to create a mock-up of a complex curved surface for a building and simulate the process of construction production in the design development and construction management. It is difficult to create curved surfaces using only digital fabrication, and manual processes, such as bending wooden boards along curved surfaces, are required. Therefore, students were required to combine digital fabrication knowledge with hands-on manufacturing skills, including hand-bending and experiential learning, which helped students think about the necessary processes for constructing the shapes they designed.

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.595-602
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• 2007

Recently, concrete structures with carbon fiber reinforced polymer (CFRP) reinforcements have been commonly used for the bridge and building construction. In this paper, pier caps were strengthened by prestressed near surface mounted CFRP. To verify the effectiveness of the strengthening method, 7 pier cap specimens were fabricated. One specimen was designed for control, two for external prestressing steel strands, two for CFRP plates, and two for CFRP bars. Experimental variables consist of type of reinforcement materials and prestressing levels. The results of laboratory have shown that the ultimate load capacities of prestressed near surface mounted CFRP specimens were about $20{\sim}33%$ greater than that of a control specimen. Also, ultimate load capacities of prestressed near surface mounted CFRP specimens were similar to those of external prestressing specimens with steel strands.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.444-447
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• 2006

Construction managers need to pay a close attention to the resource utilization in order to deliver the construction project successfully. Construction scheduling is crucial for resource control in that it provides information when and how much to bring down work force to sites. In scheduling, activity duration is projected based on the productivity of historical data or the intuition of scheduler. This paper studies the opportunity of applying cost-based productivity for estimating activity duration. For cost-based productivity, the cost of resource is used as an input and the work quantities as an output. Out of historical data, regression model has been developed to understand the validity of applying cost-based productivity in projecting activity duration. The result of study will work as a prerequisite for implementing the environment of database-based construction scheduling.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.449-454
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• 2008

The purpose of this study is to analyze, applications of the construction management delivery systems according to characteristics of facilities. The adapted research method is to selected four mall in the capital region and then divided them into two groups: CM for Fee or CM at Risk. After analyze each applications and administrations, it could propose proper applications of CM for fee according to CM at Risk. The results of this study are as follows: 1) the CM for Fee was suitable for the projects focused on completing on time and constructing the effective business plan of quality control, and 2) the CM at Risk was suitable for the projects concentrated on the cost reduction through shorten the construction time and the related businesses on quality control.

• Journal of the Korea Concrete Institute
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• v.25 no.2
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• pp.195-200
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• 2013

New thermal crack control system for mass concrete was developed to increase quality and to save construction period and cost. The principle of this system is that the curing water having proper temperature is supplied automatically to the surface of mass concrete member to keep the temperature difference between center and surface of concrete less than generally recommended temperature difference ($20^{\circ}C$). Mock-up test was conducted to investigate the validity of newly developed curing system. As a result, no crack was founded in the specimen using automated curing system developed in this study, while many cracks occurred in another specimen without automated curing system. It was also confirmed that the strength and the durability of the concrete cured by automated curing system were improved.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.495-498
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• 2007

The latest parceling-out price upper limit ancestor memorial service enforcement, Sale in lots circle is elated interest of society each floor for construction working expenses by open etc. but private investment law for society basis facilities, because circle that is presenting in parceling-out price upper limit ancestor memorial service back is different system (configuration item), cross is expected. A lot of study results connected with cost control expense arbor in the mountains etc. were presented until present, but persistent DB expulsion prohibition. Cost information is standardization unpreparedness of system. It is real condition that is hoarded since research and development by practical use plan presentation unpreparedness etc. Therefore, in this study, desire does actual date use plan presentation by purpose through DB construction after process by information form of good quality so that can collects efficiently and manages and utilizes at construction production step flag firm' s results data which is achieved. Can utilize to data of tool development that maximize ultimately comprehension about employer' s business and business order ability through persuasion, and diverts in cost control business hereafter.