• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.49-56
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• 2016

Recent research has been ongoing for modular buildings in the country and interest increases. However, the activation of modular building projects is obstructed in the construction industry. There are many reasons to identity for this obstruction but one issue should be focussed. Modular buildings require to change the existing construction production system to a new construction production system, which is factory production - transportation - erection. However, the existing project delivery system in the public sector could not be adapted for this new construction production system due to the obligation of multi prime contract use, such as electrical, communication, fire fighting contracts by Law. Therefore, modular buildings in the existing project delivery system are separately contracted by multi prime contracts and modular units composed of the buildings are contracted by an architectural prime contractor as a commodity. As results, construction costs are increased, potential quality problems are raised and the existing project delivery system is finally an obstacle not to maximize benefits of the modular buildings. In this paper, we propose a new project delivery system for the modular buildings to adapt then ew construction production system.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.69-77
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• 2017

By producing pre-engineered modular system in the factory, It is enable to expedite construction and can be distinguished from two types by the method resisting load. One is the open-sided modular system composed of beams and columns. The other is enclosed modular system composed of panels and studs. Of the modular systems, the open-sided modular system buildings the connection between modules are difficult due to closed member sections, and the overall strength is reduced as a result of local buckling. In this study, in order to solve these problems, a modular system with folded steel members filled with concrete are proposed. The capacity spectrum method presented in ATC 40 is used for seismic performance assessment of the proposed model structure and the structure with conventional steel members. The analysis results show that at the performance point of each model the number and rotation of plastic hinge formed in the proposed modular system are smaller than those in the conventional system. Based on this observation it is concluded that the proposed system with composite sections has superior seismic capacity compared with conventional system.

• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.138-146
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• 2014

Modular construction is one of the arising issues in the Korean construction industry due to shorter construction period and higher productivity on site. It is also expected that modular construction market would expand rapidly because of increasing demand of small houses by nuclear families and eco-friendly construction. However modular construction cases have been limited in Korea because of little demand in the market and the construction prices are even higher that the regular reinforced concrete methods. Even worse, because there is no standard bill of services exists in the industry, it may lead to the risk of construction expenses. So, the purpose of this study is focused on the development of bill of services which reflects characteristics and process of modular construction. In order to do this, the concepts and process of modular construction, WBS and CBS are analyzed. Analyses of the case studies and experts interview were executed so that proper principles for organizing bill of service of modular construction is established. Finally according to the 3 steps of modular construction, factory manufacturing, on-site modular construction and on-site general construction, the standard bill of services were suggested with the related coding system.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.12-20
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• 2015

Construction industry pays attention to modular construction recently which based on factory production not on labor intensive site production. Since modular construction has high time shortening effect and easiness of demolition and recycling, it has been applied to the temporary residential building. Domestic modular construction market are not activated yet, however, due to the high initial cost to realize modular construction. This study proposes demand-sensitized movable modular building in order to reduce the financial burden. The study compares between RC method building and Modular building which moves building when the demand falls off from Life-Cycle Cost's viewpoint. As a result of the economical evaluation, RC method achieved profits faster than Modular model, but Modular model's gross earnings during the life-cycle are much bigger than RC method. In other words, the result means that the market-sensitized movement of the modular building would be an economci choice in Life-Cycle Costing aspect.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.78-86
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• 2014

Modular system is a construction method which installs factory-manufactured units on site. It enables to reduce the duration and improve the quality of the construction. Nevertheless, the unit modular system is restrictively applied to domestic market such as barracks, education facilities, low-rise housing. To motivate the application of unit modular system, this study figures out important attributes of the unit modular system in a domestic construction market. Finally this study suggest marketing strategies and influential factors by Importance-Performance Analysis(IPA) based on those attributes focusing on the apartment housing. As a result, Unit modular System in the domestic market has strength on constructability, but it show weakness on usability and economic aspects which are more important in apartment housing market. Thus an improved technology in usability and economic aspects are required to activate the market.

• Korean Journal of Construction Engineering and Management
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• v.18 no.6
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• pp.98-108
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• 2017

Recently, the development of middle and high-rise building technology using modular construction method has emphasized the importance of site construction error management. The modular construction method is very limited to adjust the construction error in the field because of the factory production characteristics. Therefore, in order to prevent the construction error in advance, a management plan reflecting the characteristics of the modular construction method is required, and it is important to make the decision of the construction participant at each stage. This study analyzed the factor of construction error of modular construction and suggested a decision support model for construction error management based on construction process. The result of this study is expected to be a guideline for the modular construction participant to derive the construction error management plan.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.628-631
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• 2006

Modular Construction is a method, which factory-produced units are transferred to on-site and assembled to form complete buildings. It is expected that its demand will increase gradually. Because it has some advantages such as duration reduction, movement, reuse and environmental friendliness etc. For the Modular Construction to be introduced and applied, we needs the objective and reasonable performance criteria. This study presents the acoustic performance criteria of the modular building. For this one, this paper reviews legal standard related to performance, analyzes the performance evaluation and survey on pilot projects. The presented performance criteria can be specifically asked the demand by owner in a design guideline. In addition, it makes designer and general contractor accomplish target performance. Eventually, it can improve the performance of Modular Building.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.124-134
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• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.

• Korean Journal of Construction Engineering and Management
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• v.24 no.2
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• pp.37-49
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• 2023

In this study, we proposed resource allocation methodologies to improve the productivity of steel bridge manufacturing plants based on the constraint theory which is very popular in the area of manufacturing industries. To this end, after defining the painting process as a bottleneck, three resource allocation methodologies were developed: Operation Specific Resource Allocation (OSRA), Product Specific Resource Allocation (PSRA), and General Resource Allocation (GRA). As a result of experiments for performance evaluation using a simulation model of the steel bridge supply chain, GRA showed the best performance in terms of the Number of Work-In-Process (NWIP) and Waiting Time (WT), in particular, as workload itself and its variability were increased, the performance gap with the specific resource allocation became further deepened. On average, GRA reduced NWIP by 36.2% and WT by 34.6% compared to OSRA, and reduced NWIP by 71.0% and WT by 70.4% compared to PSRA. The reduction of NWIP and WT means alleviating the bottleneck of the painting process, which eventually means that the productivity of the steel bridge manufacturing plant has improved.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.164-174
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• 2013

It has been seriously difficult to create demand of modular construction because Korean modular method has been considered as container house or lightweight steel house. Actually, barrier factor of modular construction for activation was difficult to produce modular continuously in factories based on stable amount of demands. So, this research found successive factors of modular construction and proposed the method of demand creation through a plethora of case analysis by building types. In addition, this research found the scale of modular potential market. Owners will be able to use this strategy that is proposed in this research when they make a decision about construction system. Also, the modular construction can make potential market in Korea. As a result, modular system producer can make their business strategies and make continuous demand by conjugating the method of creating demand for modular construction which is proposed in this research.