• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.89-99
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• 2010

Military Barracks and Bachelor Officer's Quarters are public buildings representing architectural characteristics with repeating the same room modules. These buildings require easy dismantling and reusing for the next generation' military re-organization. For these reasons, since 2005, the modular construction has been applied to military buildings. The most important factors required for modular military buildings are standardization, lowcost construction and reusable construction method. However, conventional modular building system have not been matched with these requirements. This study suggests a new modular system for Bachelor Officer's Quarters using Six-sigma design tool. To reflect the voices of customers, market study and surveys were carried out. Through the QFD, the voices of customers were converted into quality characteristics of building system for BOQ. The various design concepts meeting customer's requirement were derived by the QFD and Pugh matrix methodology. The proposed modular building system shows 80% increased factory production rate and 62% decreased weight of steel frame as compared with the conventional modular building system.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.33-41
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• 2017

A modular specification is a contract document that specifies the requirements of production, transformation and installation in a modular construction. A problem of the currently used specification is that it does not guarantee the level of performance required by the modular construction and fails to accommodate unique characteristics of each construction because it widely uses the standard specification as it is. This study proposes a specification that reflects the unique feature of modular construction in order to improve the quality of modular construction. Research focuses on the leakage in waterproof and mechanical equipment because it is the area with the highest rate of defects. This study suggests ways to improve the modular specification as follows: 1)Descriptive specifying (following MasterFormat) 2)Propose leakage verification method and test clause 3) Reflect characteristic of modular construction. Proposed modifications to modular specification are reviewed by experts for validation and their opinion verifies suggested improvements as a way to secure the quality of modular construction and to promise characteristics of the modular specification. This improvement will be used for reference when writing construction project specification, which can be an important contract document, so that it could lower occurrence rate of the modular defects.

• 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.22 no.3
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• pp.31-39
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• 2021

The modular construction method is an off-site construction method using built-in structures from the manufacturing facilities. Modular construction is commonly applied to buildings which have relatively smaller and simpler structures than other types of buildings. Although modular building has emerged in the domestic construction industry as an alternative building strategy, previous researches on the environmental characteristics of modular building has not been comprehensively studied. Thus, this study empirically analyzed the insulation performance of thermal bridge and condensation parts of the modular buildings by using IR image analysis, Air-Surface Temperature Ratio method, and temperature difference ratio. The insulation performance analysis was conducted by comparing a modular building and a RC building in Seoul. The results shows that there was no significant difference between insulation performances of RC building and modular building. Furthermore

• Journal of the Korean housing association
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• v.27 no.6
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• pp.137-144
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• 2016

In modular architecture, manufacturing drawing which includes whole information for modular unit production is essential since works for modular unit have to be performed in manufacturing factory not construction field. Although the manufacturing drawing is important as known it is insufficient to utilize the manufacturing drawing in modular architecture project and this makes modular unit low-quality with re-work and work time delay. To prevent low-quality modular unit caused by insufficient manufacturing drawing, in this research firstly manufacturing drawing's current situation and error cases in manufacturing phase of past modular housing project were analyzed, and correlation between reduction of errors occurance frequency and improving manufacturing drawing was verified. Secondly manufacturing drawing improvement factors were deducted in interior, furniture, mechanical work phase which errors' occurance rate is high and the way of deducting manufacturing drawing lists and contents were suggested with light-weight work as an example in case of new type of errors occurance. A series of research process can contribute to good-quality modular unit by errors reduction. As a result of research, about half of errors occurance can be reduced with suggested manufacturing drawing improvement factors. And the manufacturing drawing process can contribute to modular production which have uniform quality.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.642-647
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• 2006

Recently Ministry of National Defense is reconstructing old facilities using modular construction method for enhancing soldiers' quality of living. In the future, the use of modular construction method is expected to be increased. But in beginning stage as ROK military facilities that was built by modular was not designed and constructed efficiently, problems for pilot projects need to be analyzed by phases and construction methods should be improved. For the maximized efficiency, design should be made to minimize on-site works, factory automation in an assembly plant should be installed for the better productivity, roads that will be used for transportation should be checked, and joint and connection methods between modules in on-site assembly should be improved for a better quality.

• 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.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.595-605
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• 2023

With the escalating prevalence of modular construction projects, there is a concurrent surge in scholarly and industrial intrigue in this domain, leading to a broadened spectrum of its applications. Modular construction, inherently facilitated by controlled factory settings, boasts the capability to consistently deliver edifices of superior quality. To optimize this advantage, the judicious integration of quality assurance methodologies during the site-specific phases of lifting and assembly is non-negotiable. This research embarked on a survey directed at project stakeholders, aiming to gauge the perceived significance and efficaciousness of prevailing quality preservation and oversight protocols during the aforementioned site stages, subsequently employing the Importance-Performance Analysis(IPA) for data interpretation. The findings elucidated that, while a majority of quality assurance procedures were adeptly executed, perceptual disparities existed among stakeholders regarding certain aspects, prompting recommendations for enhancement. This investigative endeavor lays a foundation, aiding future studies in amplifying the quality assurance cognizance among professionals during modular construction's site-assembly phase.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.101-111
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• 2015

The modular construction method has been getting more attention followed by global eco-friendly trend as the domestic construction industry has focused more on remodeling and extension work. The modular construction method is an industrialized construction system which is not likely as the existing construction method it manufactures more than 70% modules at the factory then assembling can be completed in a short amount of time on site. The modular construction method has various strengths; shortening of construction period by on-site work decrease, weight pressure reduction by usage of light steel frames and cost saving by repetitive manufacturing. However, it is currently not expanded due to the existing commercialized construction method. Therefore, this research is in order to help the related authorities make decisions to select the construction method and motivate expansion of modular construction method which can be utilized effectively in the extension works. The intention of this research is to stress differentiation from other construction methods in construction period, construction expenses, labor and forces by comparing and analyzing actual cases, to inform competitiveness of modular construction method by concrete effect analysis and to support adoption of the modular construction method into the domestic industry.

• Journal of the Korea Institute of Building Construction
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• v.22 no.5
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• pp.485-496
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• 2022

Modular construction projects offer advantageous over conventional construction projects in the area of quality control through factory production. However, as clear standards and definitions for quality control activities have yet to be not established, it is difficult to judge the appropriateness of the scale of quality control costs, and it is also difficult to classify quality control activities by process stage. Therefore, in this study, a method for classifying quality management activities based on activity standards was presented, in addition to a method for classifying quality costs according to the PAF standards to check how effective the costs and activities are for quality control in the future. The findings of this study can be used to define the quality management activities for each stage of the modular construction project in the future, and to develop a database of evidence to determine the appropriateness of cost distribution accordingly.