• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.113-114
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• 2016

This paper proposes a technical requirements analysis of implementation of multi-trade prefabrication. Recently, there has been a rise in the use of prefabrication to minimize on-site work for time reduction to increase productivity. Prefabrication technique is evolved into multi-trade prefabrication combining other trades from single-trade prefabrication. For implementation of new technique, not only itself but complementary techniques have to be prepared. In this paper, MEP corridor rack, a major item of multi-trade prefabrication, was implemented in the test bed and its process was analyzed to find out technical requirements. As a result, comparatively high level of IT technique was required for efficient use of multi-trade prefabrication in design, lifting and construction phase. In design phase, component level of BIM library was needed for manufacturing; and in lifting phase, BIM-based site logistics process was required. Also in construction phase, laser scanning was implemented for gathering shape and geometry of the wall and slab that were attached to multi-trade prefabrication module.

• Journal of KIISE:Software and Applications
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• v.31 no.3
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• pp.308-316
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• 2004

This paper proposed mediator agent system that guarantees reciprocity to attendances in bilateral negotiations for electronic commerce that is different from regular commercial transactions. The optimal agreement was supposed to provide the total maximum profits and the minimum difference in profits of both attendances in negotiations. In the mediator agent system, mediator agent conducted the negotiations considering multi attributes of product and Multi Attribute Utility Theory(MAUT) was applied to evaluate the profits of buyer and seller. 1'he negotiation model in mediator agent system was transformed into linear programming according to the information of bargain for attendances in negotiations. In order to compare with mediator agent system under the same conditions of reciprocity, another negotiation agent system was implemented using trade-off mechanism that is an algorithm for agent interactions in negotiation. The negotiation agent system using trade-off mechanism did not guarantee the optimal agreement, whereas mediator agent system provided attendances in negotiations with optimal agreement rapidly in comparison with trade-off mechanism.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.76-77
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• 2015

In construction industry, management of construction factors such as cost, schedule, quality and safety is the most important key for delivering successful projects. According to the Smart Market Report, a magazine specialized in construction industry, recently said 'Off-site Prefabrication' is a significant trend related with construction productivity in global construction industry. It is a kind of practice shift from On-site to Off-site. A lot of general contractors in oversea have been using 'Multi-trade MEP Ceiling Rack Prefabrication' method for getting benefits such as decreased cost & schedule and increased labor productivity. Thus, in this paper, critical management factors at each phase from design to installation was derived by researching case studies. Forwardly, it can be a basic guideline for applying Multi-trade MEP Ceiling Rack Prefabrication in Korea construction industry.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.84-85
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• 2013

Integrating multi-trade works system helps to reduce to minimize the conflict of subcontract business and improve communication to increase productivity of construction. However it takes such a big risk if subcontract of integrating multi-trade works went bankrupt during the project so some of construction companies executed to only small project and it's not sufficient to adopt overall project. This paper suggested the improvement scheme of work classification integrating multi-trade works, which takes a consideration into work zoning in order to apply current work situation.

• Journal of Korea Trade
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• v.23 no.3
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• pp.118-137
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• 2019

Purpose - As global trade disputes intensify and global trade uncertainty increases due to the prevailing trade protectionism all over the world, mega-FTAs such as the RCEP and CPTPP are suggested as strategic trade policy options for export-driven small open economies, such as Korea. This paper aims to provide a comprehensive analysis of Korea's mega-FTA participation and the induced implications for the Korean economy. Design/methodology - We use a multi-region, multi-sector global CGE model, and investigate the different effects of both the US-China and US-EU trade wars on the relative changes in GDP, welfare, and trade under different trade policy regimes; (i) Korea does not participate in any mega-FTA, (ii) Korea participates in the RCEP, and (iii) Korea participates in the CPTPP. Findings - We show, among others, that though industrial effects might be largely varied, the overall enlarging of free trade zones through multilateral mega-FTA participation may contribute significantly to the macroeconomic soundness and stability of Korea, even when global trade protectionism prevails. Under RCEP and CPTPP trade regimes, Korea's GDP may increase even when the global trade environment deteriorates as trade wars occur and intensify between the US and China, or between the US and EU. It is also estimated that RCEP participation increases Korea's GDP, welfare (measured in equivalent variation), and total trade by 1.12%, $1.09 billion, and 2.54%, respectively, while CPTPP participation increases them by 0.19%, $0.92 billion, and 0.13%, respectively. Originality/value - Existing studies usually focus on the direct impacts of mega-FTA participation on macroeconomic variables such as GDP, welfare, and trade, and do not consider the possible buffer effects of a mega-FTA when the global trade environment worsens. In this paper, we analyze and quantify not only the direct impacts of RCEP and CPTPP on the main macroeconomic variables but also the possible buffer effects of the RCEP and CPTPP in the cases of the US-China and US-EU trade wars.

• Structural Engineering and Mechanics
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• v.71 no.2
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• pp.139-151
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• 2019

In a project schedule, it is possible to reduce the time required to complete a project by allocating extra resources for critical activities. However, accelerating a project causes additional expense. This issue is addressed by finding optimal set of time-cost alternatives and is known as the time-cost trade-off problem in the literature. The aim of this study is to identify the optimal set of time-cost alternatives using a multiobjective teaching-learning-based optimization (TLBO) algorithm integrated with the non-dominated sorting concept and is applied to successfully optimize the projects ranging from a small to medium large projects. Numerical simulations indicate that the utilized model searches and identifies optimal / near optimal trade-offs between project time and cost in construction engineering and management. Therefore, it is concluded that the developed TLBO-based multiobjective approach offers satisfactorily solutions for time-cost trade-off optimization problems.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.385-388
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• 2002

The construction industry has complicated production processes with diverse disciplines and subcontractors, which is the major cause of lowered productivity. To solve this problem, multi-trade subcontract system is recently suggested. Some general construction companies have applied this method to some sections of work process. However, this is in the early stage of application. The purpose of this study is to define an integrated contract package for improving both contractor and subcontractor efficiency. First, this study recognizes construction company to need of multi-trade subcontract system. Finally, it suggests feasible activities which can be useful for a construction company to apply to this subcontract system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.158-166
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• 2019

In pursuing carbon emission reduction efforts, companies have focused for the most part on reducing emissions due to the more efficient equipment and facilities. However they overlook a significant source of carbon emissions, one that is driven by operational policies. Currently companies are looking for solutions to reduce carbon emissions associated with their operations. Operational adjustments, such as modifications in order quantities could an effective way in reducing carbon emissions in the supply chain. Also, Cap-and-Trade mechanism is generally accepted as on of the most effective market-based mechanism to reduce carbon emissions. In this paper, we investigate a supply chain with single manufacturer and multiple retailers multi-product inventory model under the cap-and-trade system incorporating the carbon emissions caused by transportation and warehousing activities. Also, we provide an iterative solution algorithm and derive the common order interval and the number of intervals for each product. We show by numerical example that the inventory model incorporating cap & trade mechanism can reduce total cost and carbon emissions compared to the classical inventory model. Using the numerical examples, we also investigates different carbon price on the performance of the inventory model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.61-68
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• 2019

Currently many companies are interested in reduction of the carbon emissions associated with their supply chain activities such as transportation and operations. Operational decisions, such as modifications in order quantities could an effective way in reducing carbon emissions in the supply chain. Cap-and-trade regulation, sometimes called emissions trading, is a market-based tool to limit greenhouse gas emissions. Under cap-and-trade regulation, emission credits are allocated to the firms and the firms trades emissions under cap-and-trade schemes. In this paper, we propose a single-manufacturer single-buyer two-echelon supply chain problem under the cap-and-trade mechanism incorporating the carbon emissions caused by transportation and warehousing activities where a single manufacturer produces a family of items in order to deliver a family of items to a single buyer at a fixed interval of time for effective implementation of Just-In-Time (JIT) Purchasing. An integrated multi-product lot-splitting model of facilitating multiple shipments in small lots between buyer and manufacturer is developed in a JIT Purchasing environment. Also, an iterative heuristic algorithm is developed to derive the common order interval, the number of intervals for each product and the number of shipments between the buyer and the manufacturer during the common interval. A numerical example is given to illustrate the savings in reduction of total cost and carbon emissions by the inventory model incorporating cap-and-trade mechanism compared to the classical inventory model. The proposed inventory model could be useful for the practical solution of two-echelon supply chain inventory problem under cap-and-trade mechanism.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.35-44
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• 2013

Multi-trade Contract Method was introduced as a means of cutting down construction cost of public housing for low income people. Before a specific project delivery method is applied to large public construction project, it is necessary to discuss all the issues raised up from all the parties in construction industry and all the issues which can impact project performance. Thus the interviews were conducted with industrial professionals from diverse organizations and previous studies were investigated to figure out how this newly introduced project delivery method may impact owner's role and responsibility and project performance in terms of cost, schedule, quality and risk. Under the Multi-trade Contract Method, project owner's management tasks will be highly increased, so it should be checked out if the owner can do its role and responsibility. Public owner's organization also needs to be changed and proper project management procedure and system need to be established. In addition, for efficient application of Multi-trade Contract Method, public owner should consider diverse management approach to deliver the project, and how to select and maintain qualified specialty trades.