• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6128-6134
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• 2012

In so many real estate development projects, there were strong needs to have a powerful tool to check feasibility of those projects. But there were not enough tool and measure to cover risk of real estate development and construction. Therefore I tried to find a real tool to measure investment value of development properly and efficiently, by means of case studies of many real estate development projects. Finally I found a fact that no tools of investment value analysis are perfect and efficient to hedge all kinds of risks in projects. Especially NPV(Net Present Value) and IRR(Internal Rate of Return) were not sufficient by themselves to measure investment value. So I found out that MIRR(Modified IRR), XIRR(X-IRR), ARR(Average Rate of Return), PP(Payback Period) and so on, would be supplementaries of proper and efficient investment value analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1424-1432
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• 2009

For the efficient management of hospital sickbeds, it is important to predict the length of stay (LoS) of appendicitis patients. This study analyzed the patient data to find factors that show high positive correlation with LoS, build LoS prediction models using neural network and decision tree models, and compare their performance. In order to increase the prediction accuracy, we applied the ensemble techniques such as bagging and boosting. Experimental results show that decision tree model which was built with less number of variables shows prediction accuracy almost equal to that of neural network model, and that bagging is better than boosting. In conclusion, since the decision tree model which provides better explanation than neural network model can well predict the LoS of appendicitis patients and can also be used to select the input variables, it is recommended that hospitals make use of the decision tree techniques more actively.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.10a
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• pp.151-157
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• 1999

선석계획 및 크레인 일정계획은 컨테이너 터미널에서 입항하는 선박들의 빈번한 변동상황에 능동적으로 대처하고 유연하면서도 신속한 의사결정이 가능하도록 여러 명의 전문가가 장기적인 계획을 바탕으로 지속적으로 수정 보완해 나가는 방법으로 이루어지고 있다. 본 논문에서는 선사 및 컨테이너 터미널에서 수시로 변경되는 다양한 요구조건을 수용하는 최적의 선석 및 크레인 일정계획 수립을 위하여 제약만족기법과 휴리스틱 교정(Heuristic Repair)기법을 이용하였다. 선석계획 및 크레인 일정 계획문제는 기본적으로 제약조건 만족문제로 정형화할 수 있지만 선박의 접안위치를 결정하는 문제는 목적함수를 가지는 최적화문제이다. 따라서 이 문제는 제약조건 만족문제와 최적화문제가 혼합된 문제(CSOP, Constraint Satisfaction and Optimization Problem)로 볼 수 있다. 이러한 문제를 해결하기 위해서 각 선박의 최적 전압위치를 찾고 최우선 순위 선박의 최적 접안위치로부터 주어진 모든 제약조건을 만족하는 해를 찾는 탐색기법을 활용했고 휴리스틱 교정기법을 사용해서 제약만족기법에서 찾은 해를 교정했다. 우선순위가 가장 높은 선박부터 탐색을 하기 위해 Variable Ordering 기법을 사용했고 그 선박의 최적 접안위치부터 탐색을 해 나가는 Value Ordering 기법을 사용하였다. 실제 부산 신선대 컨테이너 터미널의 선석계획자료를 사용해서 실험을 하였다.

• Journal of Korea Water Resources Association
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• v.50 no.3
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• pp.169-179
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• 2017

Recently, due to global warming and climate change in Korea, local heavy storm occurs frequently. In this study, the risky areas for flooding in urban areas are analyzed for flood inundation based on two-dimensional urban flood runoff model (XP-SWMM) focusing on coastal high flood-risk urban areas. In addition, the MCDM (Multi-Criteria Decision Making) technique is utilized in order to establish the flood defense structural measures. The alternative flood reduction method are compared and the optimum flood defense measures are selected. A simulation model was used with three structural flood prevention measures (drainage pipe construction, water detention, flood pumping station). In order to decrease the flooding area, flood assessment criteria are suggested (flooded area, maximum inundation depth, damaged residential area, construction cost). Priorities of alternatives are determined by using compromise programming. As a result, the optimal flood defence alternative suggested for Janghang Zone 1 is flood pumping station and for Janghang Zone 2, 3 are drainage pipe construction.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.3-15
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• 2013

The purpose of this study is to propose a methodology for operating variable speed limit (VSL) strategies in freeway work zones. A notable feature in this study is to incorporate a multi-criteria decision making process into deriving better VSL strategies. Decision criteria in this study include operational efficiency, safety, and environmental impacts. Travel speed, acceleration noise, and CO2 were used as performance measures for evaluating VSL strategies. A multi-criteria value function was developed through an analytical hierarchical process (AHP) for representing expert's knowledge. Then, a variety of VSL operations scenarios were investigated utilizing a microscopic traffic simulation suite, VISSIM. The proposed methodology would be useful in supporting more efficient, safer, and more environment-friendly traffic operations and control in freeway work zones.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.183-196
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• 2017

In this study, policy evaluation scheme was established to encourage the efficient implementation of EcoMobility which has been expanding gradually all around the world. A total of eight evaluation goals and 22 evaluation items are reviewed and suggested based on the three major evaluation categories of "Basic elements for EcoMobility", "Land use and transport system for EcoMobility", and "Implications and impact of EcoMobility". The results of this study are as follows: the result of AHP analysis which reflects only the hierarchical structure shows a high priority in "Elements for EcoMobility promotion", "Eco-fiendly transport infrastructure", and "Safety in transport". While in result of ANP which considered the elements' dependencies, "Eco-fiendly transport Services", "Welfare in transport", and "Environment by transport" have high weights and importances. In conclusion, this study would be useful to make reasonable judgment based on the analysis results of the two techniques in order to ensure reliability in evaluation of EcoMobility policy. Furthermore we have confirmed appropriate evaluation technique between AHP and ANP which is better to reflect the features of EcoMobility.

• 한국벤처창업학회:학술대회논문집
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• 2022.11a
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• pp.167-173
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• 2022

임팩트투자는 재무적인 수익과 더불어 사회에 긍정적인 영향을 만들고자 하는 의도를 가진 기업, 조직, 펀드를 대상으로 하는 투자 방식으로서 사회적 문제를 해결하기 위해 혁신적인 기술과 아이디어를 기잔 소셜벤처 기업에 재무적 지원을 위한 초기단계 투자로서 많은 관심을 받고 있다. 임팩트투자자는 재무적 수익과 사회적 가치추구라는 이중적인 판단 요인 때문에 사회적가치지표(SVI: Social Value Index)를 투자판단에 참고로 활용하고 있으나 투자를 결심하는 판단요인에 있어서는 여전히 개인의 경험과 주관적인 판단에 의존하고 있는 실정이다. 본 연구를 통하여 임팩트투자자가 복합적으로 고려하는 투자판단 요인들에 대한 타당도와 상대적 가중치를 객관화 하고, 재무적 수익과 사회적 가치의 이중적이 가치판단 중에서 어느 쪽을 더 주요하게 고민하는 지에 대하여 분석하였다. 본 연구는 판단분석기법을 활용하였으며 '임팩트투자자의 소셜벤처 투자결정에 대한 종합적인 평가'를 판단문제로 정의하고, 임팩트투자자의 투자의사결정 요인을 도출하기 위하여 투자자로서 재무적 이익과 회수 가능성 판단을 위한 ①초기투자단계에서의 투자의사결정 요인, 사회에 미치는 영향과 파급력, 소셜벤처의 상생과 연대를 위한 ②창업가(팀)의 정치적 기술, 임팩트투자펀드 조성 목적에 부합하는 ③소셜벤처기업의 소셜미션 등 세가지의 분류로 구성하여 연구를 진행하였다.

• Journal of Korea Entertainment Industry Association
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• v.15 no.2
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• pp.1-10
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• 2021

The purpose of this study is to explore a significant HPWS(High Performance Work System) model for the entertainment industry. HPWS is one of the most studied themes for managing human resources as well as a set of practices to elicit employees' commitment to an organization. Recently, the entertainment industry is growing rapidly, but it is difficult for entertainment firms to retain a stable profit unlike the manufacturing industry. This is because the performance of entertainment business tends to rely heavily on the capabilities and synergy of human resources. In order to suggest a systematic way to manage these, this research identified an effective HPWS model for entertainment business and provides a competitive advantage to entertainment firms, using ANP(Analytic Network Process). ANP is a multicriteria decision making technique that allows dependences and feedbacks among decision elements in the hierarchical or network structures in a holistic manner. The pairwise comparison data that prioritized the criteria of HPWS was collected from 28 team leaders in entertainment firms. According to our results, the most critical factor for HPWS in entertainment business is "employee involvement in decision-making." The sub-factors such as "open communication," "distributive decision-making," and "performance-driven reward" have a greater effect. These findings could provide implications for entertainment firms to determine which practices should be taken into account to accomplish HPWS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.639-645
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• 2018

This paper is intended to develop a decision model that can be applied to autonomous vehicles and autonomous mobile vehicles. The developed module has an independent configuration for application in various driving environments and is based on a platform for organically operating them. Each module is studied for decision making on lane changes and for securing safety through reinforcement learning using a deep learning technique. The autonomous mobile moving body operating to change the driving state has a characteristic where the next operation of the mobile body can be determined only if the definition of the speed determination model (according to its functions) and the lane change decision are correctly preceded. Also, if all the moving bodies traveling on a general road are equipped with an autonomous driving function, it is difficult to consider the factors that may occur between each mobile unit from unexpected environmental changes. Considering these factors, we applied the decision model to the platform and studied the lane change decision system for implementation of the platform. We studied the decision model using a modular learning method to reduce system complexity, to reduce the learning time, and to consider model replacement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7061-7070
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• 2015

Multi-Response Surface Optimization aims at finding the optimal setting of input variables considering multiple responses simultaneously. The Weighted Mean Squared Error (WMSE) minimization approach, which imposes a different weight on the two components of mean squared error, squared bias and variance, first obtains WMSE for each response and then minimizes all the WMSEs at once. Most of the methods proposed for the WMSE minimization approach to date are classified into the prior preference articulation approach, which requires that a decision maker (DM) provides his/her preference information a priori. However, it is quite difficult for the DM to provide such information in advance, because he/she cannot experience the relationships or conflicts among the responses. To overcome this limitation, this paper proposes a posterior preference articulation method to the WMSE minimization approach. The proposed method first generates all (or most) of the nondominated solutions without the DM's preference information. Then, the DM selects the best one from the set of nondominated solutions a posteriori. Its advantage is that it provides an opportunity for the DM to understand the tradeoffs in the entire set of nondominated solutions and effectively obtains the most preferred solution suitable for his/her preference structure.