• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.158-159
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• 2016

Construction project consists of several stages such as planning, design, construction, operation/maintain, etc. Decisions made in the planning and design stage have a significant impact on the construction and operation/maintain stages. Identifying key resources contributing to duration and cost of design alternatives is an important measure to achieve effective coordination between design and construction. This study proposes a method which finds an optimal design alternative by taking into account of resource planning, expected duration, and cost in construction stage. Base on literature review relative to the assessment of design alternatives, a method which predicts required resources, duration, and cost of the design alternative is established. Then, a method that identifies an optimal design alternative based on the preference of a certain project criteria is developed. Finally, a case study is presented.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.1
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• pp.53-61
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• 2008

In this research, the layout and geometry of U-type ribs in the part, including significant process conditions, are automatically optimized to reduce part warpage with robustness in consideration. The optimization procedure are based on an iterative redesign methodology integrated with computer aided injection molding simulation, Taguchi's Design of Experiment(DOE), and a direct search-based optimization method. The robustness of a design alternative is efficiently measured by introducing composite noise factor and Taguchi's signal-to-noise ratio. As a solution search methodology, the modified design space reduction method based on orthogonal arrays is employed to exploit an optimal robust design alternative. To illustrate the proposed methodology, a case study is performed on simulation results, where an optimal robust design alternative is obtained with a moderate number of iterations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.153-161
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• 2020

Building information modeling (BIM) is a smart construction technique that is recognized as essential for current construction facility projects. The Public Procurement Service (a construction project-ordering agency) announced a plan to introduce BIM and has required changing the operation of projects by using BIM design information. LCC analysis is essential for items, quantity, and cost information of the construction, and it is expected that efficient work will be achieved by using BIM design information. In this study, a BIM-LCC analysis system was established for selecting optimal design alternatives by actively using open KBIMS libraries. The BIM-LCC analysis system consists of a single alternative and an optimal alternative LCC analysis, but it has a limitation in that only the architecture and machine libraries have been applied. However, by applying BIM, practical use and work efficiency can be expected. In order to use the method as an LCC analysis support tool with BIM design information in the future, it will be necessary to collect user opinions and improve the UI.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.559-569
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• 1998

Cellular manufacturing system (CMS) has been recognized as an alternative to improve manufacturing productivity in conventional batch-type manufacturing systems through reducing set-up times, work-in-process inventories and throughput times by means of group technology. Most of the studies on the design of CMS assumed that each part has a unique process plan, and that its demand is known as a deterministic value despite of the probabilistic nature of the real world problems. This study suggests an approach for designing CMS, considering both alternative process plans and uncertain demand. A mathematical model is presented to show how to minimize the expected amortized and operating costs satisfying these two relaxations. Four heuristic algorithms are developed based on tabu search which is well suited for getting an optimal or near-optimal solution. Example problems are carried out to illustrate the heuristic algorithms and each of them is compared with the deterministic counterpart.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.2
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• pp.29-33
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• 2013

This study has been conducted to propose an optimal design guidance of underfloor air distribution system by examining air pattern and proper exhaust status of floor plenum using CFD (Computational Fluid Dynamics). Simulation shows deficient air pattern and exhaust status at BPG (Bypass Grille) of the current design. As a means to find an alternative design, four cases have been developed and tested. Case 1, 2 and 3 show similar results in comparison to the current design. However, case 4 shows improved air pattern and exhaust status at BPG(Bypass Grille), and has been chosen as the optimal alternative.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.662-665
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• 2008

This research attempts to develop 4D CAD function to support optimal road design by expanding the existing 4D CAD utilization system, which focused on construction phase, to the design phase. The functions such as earthwork simulation for selecting of road alignment, alternative route simulation and structure type simulation were suggested as functions to support road design. Through those virtual reality (VR) functions, visual confirmation of the condition of route and earthwork Is possible by the developed system, and an optimal alternative route can be selected by carrying out layout simulation of the alternative route. The functions presented in this research provide the decision making tools based virtual model for efficient support to road design.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.3-10
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• 2022

An estimated investment gap of $176 billion needs to be filled over the next ten years to improve America's inland waterway transportation systems. Many of these infrastructure systems are now beyond their original 50-year design life and are often behind in maintenance due to funding constraints. Therefore, long-term maintenance strategies (i.e., asset management (AM) strategies) are needed to optimize investments across these waterway systems to improve their condition. Two common AM strategies include policy-driven maintenance and performance-driven maintenance. Currently, limited research exists on selecting the optimal AM approach for managing inland waterway transportation assets. Therefore, the goal of this study is to provide a decision model that can be used to select the optimal alternative between the two AM approaches by considering key uncertainties such as asset condition, asset test results, and asset failure. We achieve this goal by addressing the decision problem as a single-criterion problem, which calculates each alternative's expected value and certain equivalence using allocated monetary values to determine the recommended alternative for optimally maintaining navigable waterways. The decision model considers estimated and predicted values based on the current state of the infrastructure. This research concludes that the performance-based approach is the optimal alternative based on the expected value obtained from the analysis. This research sets the stage for further studies on fiscal constraints that will effectively optimize these assets condition.

• Journal of the Korea Construction Safety Engineering Association
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• s.52
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• pp.58-66
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• 2011

This study presents an algorithm to select the best alternative plane among various bridge superstructure types (Steel box girder, Rational girder, PSC-I girder) using Value Engineering (VE). Economical efficiency, landscape, constructability, maintenance, stability, function of bridge superstructure were taken into consideration in the designing of bridge. Economical efficiency was evaluated for each alternative plan with optimal design considering Life Cycle Cost (LCC), Repair and rehabilitation histories and some factors were set to get reasonable results. In the application of Analytic Hierarchy Process (AHP), consistency of Pairwise Comparisons Matrix was evaluated and the best plan was determined.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.79-85
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• 2009

This study presents an algorithm to select the best alternative plane among various bridge superstructure types(Steel box girder, Rational girder, PSC-I girder) using Value Engineering(VE). Economical efficiency, landscape, constructability, maintenance, stability, function of bridge superstructure were taken into consideration in the designing of bridge. Economical efficiency was evaluated for each alternative plan with optimal design considering Life Cycle Cost(LCC). Repair and rehabilitation histories and some factors were set to get reasonable results. In the application of Analytic Hierarchy Process(AHP), consistency of Pairwise Comparisons Matrix was evaluated and the best plan was determined.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.1
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• pp.36-43
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• 2015

Optimizing multiple design characteristics which are usually in conflict with each other in the injection molding process is frequently becoming a critical problem for designers who work in this area. The purpose of this work is to develop an automated design methodology for optimizing two such design characteristics found in injection-molded parts. A value function based on decision-making theory is used as a means of evaluating the performance of a two-characteristic design alternative. Also, a design space reduction algorithm based on Taguchi's orthogonal arrays is utilized to discover an optimal design alternative. Verification of the developed design methodology is carried out for an actual model with two design characteristics, the weld line and the gate location, to be optimized in computer simulation experiments.