• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.377-383
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• 2011

This study proposed the new method of discerning the assembled parts and presuming the position of central point in a Cowl Cross Bar (CCB) using a Charge-Couple Device (CCD) camera attached to a robot in the auto assembly line. Three control points of an ellipse were decided by three reference points, which were equally distanced. The radii of these reference points were determined by the size of the object, and the repeated presumption secured the precise determination. The comparison of the central point of ellipse presumed by Randomized Hough Transform (RHT) with the part information stored in a database was used for determining the faulty part in an assembly. The method proposed in this study was applied for the real-time inspection of elliptical parts, such as bolt, nut hole and so on, connected to a CCB using a CCD camera. The findings of this study showed that the precise decision on whether the parts are inferior or not can be made irrespective of the lighting condition of industrial site and the noises of the surface of the part. In addition, the defect decision on the individual elliptic parts assembled in a CCB showed more than 98% accuracy within a 500-millisecond period at most.

• Journal of Korean Association for Spatial Structures
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• v.18 no.1
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• pp.67-75
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• 2018

Steel roof construction is on the most important and critical factors in the large spatial construction and necessary to be prepared under a radical planning. Therefore, the major management factors of steel roofing structure assembly must be critically reviewed during planning. Through the review process, it is necessary to reduce the construction cost, to prevent delays in the construction schedule, and to minimize construction errors. However, domestically due to the lack experience in large spatial constructions, a planning of roof construction is limited to have a radical planning. Especially due to unclear organization of the management factors in hierarchy, using them in reality for construction planning is difficult and reliability is low. Therefore, in this study, the goal is to conduct the major management factors in the large spatial construction. To achieve this, we have reviewed and analyzed the numbers of construction plans and construction reports and conducted a total 68 of the management factors. Based on the conducted factors, we have interviewed 16 experts with experience in large spatial construction. From the interview result, we have deduced the factors scored above 4.20 of 10 for critical factors. The results of this study will be used as a guidance for planning steel roofing structure assembly in large spatial construction. The critical factors will be provided to the site mangers for the quality management of large spatial constructions in practice.

• Architectural research
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• v.24 no.2
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• pp.21-27
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• 2022

For the past decade, South Korea had experienced catastrophic building fires, which resulted in consider-ably high number of casualties. This motivated research to develop fire-safe wall assemblies. In this study Fire Risk Analysis (FRA) is conducted as part of the project designing phase to ensure fire safety of the final product. Traditional approach was to consider fire performance at the end of the designing stage, when PASS/FAIL fire test results are required to be submitted to the Authority Having Jurisdiction (AHJ). By applying a fire risk analysis to guide the designing phase, overall fire safety of a wall assembly can be achieved more systematically as conducting FRA allows designers to clearly identify elements that are more vulnerable to fire and simply replace them with other practical options. Severity of fire risk is determined by considering the fire hazards of a wall assembly such as the exterior layer, insulation, vertical connectivity, and external ignition sources (e.g., photovoltaic panels). Frequency of fire risk is assessed based on the factors affecting fire likelihood, which are air cavity and fire-stopping applied in the design, and random design changes occurring during on-site construction. Fire risk matrix is proposed based on these fire risk factors and efforts to reduce the fire risk level associated with the wall assembly are given by systematically assessing the fire risk factors identified from fire risk analysis. Current study demonstrates how fire risk analysis can be applied to develop fire-safe walls by reducing the relevant fire risks- both severity and frequency.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.13-26
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• 2021

To promote the off-site construction (OSC) in Korea, technical innovation applied to each phase, such as design, engineering, factory production, and site assembly, is important and equally necessary is the development of management and operation methods that are different from existing construction production methods. However, the current OSC-related studies in Korea are conducted from the technical development viewpoints, such as construction methods. Additionally, few studies have been conducted to derive a management measure for successful OSC projects. Therefore, studies to derive a management measure based on a clear understanding of the core success factors of OSC projects are required. This study aims to analyze several studies related to the success factors of OSC projects conducted overseas and to show its core implications for the successful management of OSC projects in Korea. We expect this study to improve the viability of OSC projects, which will be expanded in Korea in the future.

• Land and Housing Review
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• v.10 no.3
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.253-254
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• 2023

The production plan of Precast Concrete members is closely related to the assembly plan of Precast Concrete members, and is an important management factor for the process planning of Precast Concrete construction. This may cause a delay in the construction period due to manufacturing errors occurring in the production process of members and transportation errors according to the production sequence. Therefore, it is necessary to have an efficient production plan for Precast Concrete members that can produce the necessary quantity from the point of assembly of the members and supply them in a timely manner. This study is a basic study for establishing a production plan for Precast Concrete members, and the purpose of the study is to examine the factors that affect the establishment of a production plan for Precast Concrete members. In this study, the influencing factors according to the production method and conditions when establishing a production plan for Precast Concrete members were considered. In the future, correlation analysis among influencing factors will be carried out, and it is expected that it will be used as basic data for schedule management of Precast Concrete construction and derivation of construction period calculation standards.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.129-136
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• 2010

The present annexed parking lot standards for buildings in Parking Act are categorized in 9 groups in terms of recreation, culture and assembly, housing, factory, and so on, in which same grouped facilities have uniform parking standards. The local governments have authority to itemize groups and adjust parking standards within ${\pm}50%$ ranges. These days diversity in building types and functions need more fractionated parking standards; however, most local governments focusing merely on applying strengthened parking standards in general without systematic rules of consistency. The current problem of parking standards being used is lack of regarding facility characteristics; expecially, a large sized high-tech manufacturing facility located in industrial site is still applied by same parking standards as normal manufacturing facility, even though most part of manufacturing process is automated and hence less manpower is employed. This paper presents a systematic method of analyzing parking generation unit for factory facilities in industrial site in terms of facility use and scale characteristics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.37-44
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• 2010

The present annexed parking lot standards for buildings in Parking Act are categorized in 9 groups with 13 parking standards in terms of recreation, culture and assembly, housing, factory, warehouse, and so on, in which same grouped facilities have same parking standards. These days diversity in building types and functions need more fractionated parking standards; however, most local governments focusing merely on applying strengthened parking standards in general without systematic rules of consistency. The current problem of parking standards being used is lack of regarding facility characteristics; expecially, a large sized high-tech manufacturing facility located in industrial site is still applied by same parking standards as normal manufacturing facility, even though most part of manufacturing process is automated and hence less manpower is employed. This paper presents a parking generation forecasting model for factory facilities in industrial site in terms of facility use and scale characteristics.

• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.96-106
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• 2021

The PC structure based on the OSC (Off-Site Construction) is mentioned as a representative method of innovation in the construction industry that converts the existing construction environment from site-centered to factory production-transportation-site assembly. However, recent research on PC method has focused on improving the functions of subsidiary materials and improving the production system to increase productivity and institutional / policy R&D that can be universally applied to the life-cycle stage of ordering / design /construction is insufficient. In particular, the absence of standardized cost calculation standards makes it difficult to calculate and verify of objectified appropriate construction cost. So which is an obstacle to the activation of the PC method. In this study, the standards for construction costs of domestic and foreign PC method were surveyed and similar Construction Standard Production Rates were analyzed to confirm the product structure suitable for PC method. Subsequently, the construction procedures and input resources for each PC subsidiary materials were identified through on-site surveys to derive component for subsidiary materials, and the factors of change in the product according to the construction characteristics(height, weight of subsidiary material) were verified. As a result the standard product calculation system suitable for the site installation of the PC method for apartment was presented.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.192-200
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• 2017

With the acceleration of construction industrialization, the buildings that China has adopted the construction of industrialization technology are increasing day by day, and Precast Concrete (PC) Structure technology is one of the main technologies of construction industrialization. Compared with the traditional cast-in-place concrete structure, PC structure is more conducive to shorten the construction period, reduce the number of construction workers and the site construction waste. Nevertheless, PC structure improves the requirements of hoisting machinery in the construction site, and the lay-out and selection of hoisting machinery become an important factor influencing the construction cost. The paper regards the typical tower crane in China as the research object, and establishes the time optimization model for the lifting scheme. The influence of the different precast rate on the selection of the tower crane is analyzed. This paper obtains the time variation of the tower crane under different precast rate, provides a theoretical basis for the design of precast concrete structures under the influence of assembly construction, and lays the foundation for the selection of tower crane under the precast rate.