• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.486-492
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• 2019

The system-based approach is needed to select an optimal mix of weapon systems and ship platform among a variety of design alternatives with the uncertainties of the initial required operational capability. In the early-phase design, which included a feasibility study and concept design, it is possible to cause problems when a review of the operational concept, database development, and systematic design are not done, thereby producing uncertain and unstable requirements. To select the best solution without trial-and-error, the U.S. navy has applied the set-based method for the early-phase design of a new ship-to-shore connector. The ship synthesis model plays an important role in applying the set-based method, but only a few countries possess this model and have prohibited this model from being transferred to other countries. This paper suggests a set-based method using a genetic algorithm and decision-making theory through benchmarking existing ship data. The algorithm was verified using the DDG-51 class ship synthesis model to optimize the weapon system design, which has been released for research purposes.

• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.84-94
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• 2017

Recently, domestic construction companies have increasingly engaged in international PPP projects a result of both uncertainties in the domestic construction market and low competitiveness in international EPC project business. These international PPP projects usually require long-term preparations and substantial sales costs, which make it important for decision-makers to select winning-award potential project in early stage of the projects. However, most previous research has analyzed success factors in terms of project development across all stages. Thus, this study investigated 28 success factors of 4 categories in the early stage of 31 international PPP projects. First, results indicate that unsolicited PPP projects require better implementation capabilities and financial conditions compared to solicited PPP projects. Second, implementation capability is important because it is not easy to improve as the project proceeds. Third, commercial conditions are identified as important even if conditions are not fixed in the early stage of PPP projects. Fourth, non-commercial conditions, strategy, and public interest are not found to be meaningful in the early stage of PPP projects because they can vary as the project proceeds. This study helps to improve selection criteria aimed towards more winning-award potential project in the early stage of international PPP projects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.5
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• pp.467-476
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• 2010

For the very light jet aircraft design, the design baseline configuration has been selected using the logical decision making process, and the design optimization problem is formulated by considering the airworthiness regulations as design constraints. Airworthiness regulations are the minimum requirements for the safe aircraft flight and must be considered from the conceptual design stage. After carefully selecting the airworthiness constraints and the user specified requirements, a series of design making models including the affinity diagram, nested column diagram, quality function deployment (QFD), Pugh concept selection matrix, are used to find and evaluate alternative configuration baselines. From the feasible design space searching process, the best altenative design, which satisfies the airworthiness constraints while excluding the user subjective decisions as much as possible, has been successfully derived.

• Korean Journal of Construction Engineering and Management
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• v.17 no.2
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• pp.70-79
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• 2016

The current remodeling cost estimation process is not only dependent on the historical data of new building construction, but it also has a poor linkage with risk-based estimation approach. As such, there is a high risk of falling short of initial budget. To overcome this, a risk-based estimation approach is necessary by providing a probabilistic estimation in consideration of the potential risk factors in conducting the remodeling projects. In addition, the decision-making process should be linked with the risk-based estimation results in stead of intuitive and/or experience-based estimation. This study provides a probabilistic estimation process for residential remodeling projects by developing a detailed methodology in which a step-by-step approach can be achieved. The new proposed estimation approach can help in decision-making for remodeling projects in terms of whether to proceed or not, by effectively reflecting the potential risk factors in the early stage of the project. In addition, the study can enhance the reliability of the estimation results by developing a sustainable estimation process model where a risk-based evaluation can be accomplished by setting up the cost-risk relationship database structure.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.4
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• pp.83-96
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• 2020

Traditionally social problems had been largely left to be handled by non-profit organizations, not because of lack of interests in social causes but mostly because of lack of innovative ideas to solve them in commercially viable ways. This market failure has recently been fixed by social enterprises, which manage to provide both solutions for social issues and commercially viable business models. As a result, we have been witnessing a sudden spike of public interests in these social enterprises as well as a call for empirical investigation on social enterprises by prior studies. However, empirically investigating a social enterprise has been a challenging endeavor mostly due to the insufficient number of successful social enterprises. Answering to the call in this study, we empirically investigate Goyohan Taxi, a successful social enterprise that partners with visually impaired cabdrivers and offers a taxi service, by both longitudinally interviewing the founder and adopting in vivo observation throughout the entrepreneurial journey of Goyohan Taxi. Based on the single case study method, we find that Goyohan Taxi adopts two distinctive decision-making mechanisms, the de-escalation of commitment and the orthogonality of commercial and social goals. Although generalizability of the our finding is minimal due to the limitation of single case study method, our finding contributes to the research of social entrepreneurship by offering new avenue of research in decision-making process of social entrepreneurs.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.75-87
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• 2016

This study examines the impact of government funds to venture capital on investment in early-stage firms. We provide novel explanations about this relationship focusing on mechanisms by which government funds influence the perceived uncertainty, decision about investment priority, scale economy of investment, information asymmetry in investment decision, and capital expense. We argue that venture capital's investment in early-stage firms increases as government funds increase and as government funds are explicitly directed for early-stage firms. However, we further claim that the impact of government funds on early-stage investment will be decreasing as their size increases and finally be reverted to negative impact beyond a certain amount of funds to show inverse-U relationship. Our empirical examination using data from 105 Korean venture firms active as of 2013 consistently supports the claims. This study contributes to the venture capital literature by providing novel arguments about mechanisms and effects of policy intervention in venture capital. In practice, we expect our results will provide an opportunity for relevant policy makers to review their venture support policy based on empirical evidences for policy effects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3D
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• pp.373-379
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• 2009

Cost estimation in the early phase enables government to plan public budgeting more efficiently by providing information about construction cost. However, cost estimation in the early phase is difficult to predict because only a little information can be utilized. The cost estimation method now being used by the government is calculated by length of the road multiplied by unit cost per length and shows high error rate because it cannot reflect the unique characteristics of each project. As the project is being proceeded, level of available information also changed. So, reflecting available information of a project is important. This paper divided early phase into two parts : planning phase and early design phase, and developed cost estimation model considering level of available information of each phase. Total 143 cases are utilized to find influencing variables and develop cost estimation model and model validation is done by adopting required accuracy level. This cost estimation model reflecting level of available information can be applied to public budgeting, feasibility test, and comparison between routes.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.26-33
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• 2009

The required level of detail in scheduling depends on the stages in the construction life-cycle. The objective of this study is to provide a Standardized Schedule Model (SSM) with an aim to facilitate the estimating of construction duration in the planning stage. The SSM modularizes work items; establishes relations between preceding and succeeding activities; and calculates approximate construction duration. The estimated duration of the SSM was compared with the detailed duration from the commercial scheduling tool using actual work activities. The difference showed to be ranged between -3.1% and +15%, which demonstrates that the SSM can be feasibly applied to the approximate estimation of construction duration.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.3-11
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• 2016

Recently, overseas plant orders of domestic enterprises are steadily increased, and the amount of orders in the first half of 2014 were 93% increased compared to the previous year. In addition, now which is the third quarter of 2015, overseas plant orders are already over 249.8 billion dollars so the interests of plant industry research has been increased. In the life cycle of the plant project, CM before the construction stage is to complement the uncertainties that are inherent in the early stages of the project, and from the viewpoint of supporting the rational decision-making, the importance of its role is on the rise. Among them, excavating and investing participation plan in the planning stage is an important work that has a large impact force to influence the success and failure of future project. However, the work has become a problem with frequent consultations due to decision-making, continuous modification, and inefficient repetitive tasks. Therefore, it is needed that work process should be changed to effectively accommodate. The purpose of this paper is to derive the major work items for excavating and investing participation plan in the planning stage of the plant project, and establish a standardized work process through the Delphi analysis. The result of this study is expected to be utilized for EPC companies in ensuring the technical competitiveness in planning on overseas markets, and improve the efficiency of work.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.255-266
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• 2011

In order to evaluate the environmental load occurring from the whole life cycle of a facility, LCA (Life Cycle Assessment) adopted by ISO is not only applied as an individual product but rather a complicated system involving buildings and/or infrastructure in a wide range of scope. The introducing of LCA to a wastewater reuse facility will assist to understand not only the treatment of water contaminants but also the overall system related to the interaction of involved, potential issues. This research implemented LCA for the establishment of the wastewater reuse facility. The results show that a fresh water aquatic Eco-toxicological Impact (88.3%) is the largest environment concern and the maintenance & operation phase has the most impact on the environment utilizing life cycle for the wastewater reuse facility. The civil works and chemical treatments in the maintenance & operation phase led to the biggest environmental impact. The results of this research can provide pertinent data of investigating opportunities for environmental improvement not limited to public officers regulating environmental policies, and could be used to make decisions for an environmentally sound and sustainable design in the initial phase of construction.