• 에너지공학
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• 제5권1호
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• pp.87-92
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• 1996

본 연구는 전력계통이 3개의 발전기로 구성되었고, 요금적용 시간대가 3개인 경우 동태적 최적화를 이용한 최적 가격 및 투자 정책을 도출하기 위한 것이다. 이를 위하여 최대원리법(Maximum Principle)을 이용하였으며, 종전에는 수요함수에서 고려되지 않았던 교차가격 탄력성을 수요함수에 포함시켰다. 분석 결과 다음과 같은 결론을 얻을 수 있다. 첫째, 설비가 충분한 경우 각 시간대의 최적 가격은 단기한계비용과 일치한다. 그러나 시간이 경과함에 따라 수요증가에 의하여 설비제약이 활성화되면 각 시간대의 가격은 설비비를 포함하는 장기한계비용 형태를 띄게 된다 둘째, 각 시간대에 있어서 발전기의 설비비의 분담은 요금적용 시간대의 길이에 의하여 영향을 받는다. 즉, 해당 시간대의 요금적용 시간대가 길어지면 길어질수록 해당시간대에 대응되는 설비의 설비비 분담은 감소하고, 짧아지면 질수록 설비분담은 높아지게 된다. 셋째, 동태적 분석에서의 설비투자는 기본적으로 각 시간대의 수요증가율과 같은 비율로 증가하며, 또한 신규설비 투자규모는 각 시간대의 투자설비를 서로 분담하게 된다.

• 상하수도학회지
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• 제18권2호
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• pp.145-154
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• 2004

A long-term sewer rehabilitation project consuming an enormous budget needs to be conducted systematically using an optimization skill. The optimal budgeting and ordering of priority for sewer rehabilitation projects are very important with respect to the effectiveness of investment. In this study, the sewer rehabilitation optimization model using fast-messy genetic algorithm is developed to suggest a schedule for optimal sewer rehabilitation in a subcatchment area by modifying the existing GOOSER$^{(R)}$ model having been developed using simple genetic algorithm. The sewer rehabilitation optimization model using fast-messy genetic algorithm can improve the speed converging to the optimal solution relative to GOOSER$^{(R)}$, suggesting that it is more advantageous to the sewer rehabilitation in a larger-scale subcatchment area than GOOSER.

• The Journal of Asian Finance, Economics and Business
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• 제7권7호
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• pp.113-121
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• 2020

Multi-criteria stock selection is a critical issue for effective investment since the improper stock investment might cause many problems affecting investors negatively. Investors need a range of financial indicators while they are choosing the optimal set of stocks to invest. This study aims to rank the stock of agriculture companies indexed on the Vietnam Stock Exchange Market. The data of 13 agriculture companies during the 2016-2019 periods was analyzed by analytical hierarchy process (AHP) integrated with grey relational analysis (GRA), multi-objective optimization ratio analysis (MOORA), and technique for order performance by similarity to ideal solution (TOPSIS). The AHP method is employed to determine the weights of the proposed financial ratios, and GRA, TOPSIS, and MOORA approaches are used to obtain final ranking. The results indicated that HSL is the top stock with the highest rank and GRA, MOORA, and TOPSIS rankings have strong correlation values between 0.78-1. The findings suggest that the integrated model could be implemented effectively to specific analysis of industries such as oil and gas, textiles, food, and electronics in future research. Further, other techniques like COPRAS, KEMIRA, and EDAS could be employed to evaluate the financial performance of other companies to solve investment problems.

• 유통과학연구
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• 제11권1호
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• pp.15-23
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• 2013

Purpose - During a reform period lasting 30 years, the Blue Economic Zone (BEZ) in the Shandong Peninsula has made progress in attracting foreign investment, and has acquired the foreign direct investment (FDI) essential for economic growth. It is therefore important to conduct a proactive and systematic study of FDI in the BEZ. Research design, data, methodology - This dissertation discusses the contribution of FDI on economic growth, from both a theoretical and empirical perspective. Taking seven core cities for study, statistics and econometrics are used, and panel data are used to validate FDI contribution to import and export in the BEZ. Results- FDI was found to exert both positive and negative influences on the imports and exports of the BEZ. In other words, the research findings are consistent with Trade Generated and Inverse Trade Generated theories put forward by Kojima and Mundell, among other researchers mentioned earlier in this paper. Further, FDI has greatly increased imports and exports for the BEZ. Conclusions - According to the results of this empirical study on local investment environment optimization, FDI plays an important role in foreign trade. This dissertation puts forward recommendations on using FDI to better promote economic growth in the BEZ.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제19권4호
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• pp.429-441
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• 2015

We study optimal consumption/investment and life insurance purchase rules for a wage earner with mortality risk under regime-switching financial market conditions, in a continuous time-horizon. We apply the Markov chain approximation method and suggest an efficient algorithm using parallel computing to solve the simultaneous Hamilton-Jaccobi-Bellman equations arising from the optimization problem. We provide numerical results under the utility functions of the constant relative risk aversion type, with which we illustrate the effects of regime switching on the optimal policies by comparing them with those in the absence of regime switching.

• 한국경영과학회지
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• 제34권4호
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• pp.73-89
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• 2009

Circular shareholdings among three companies are formed when company A owns stock in company B, company B owns stock in company C, and company C owns stock in company A. Since circular shareholdings among large family-controlled firms are used to give the controlling shareholder greater control or more opportunities to expropriate minority investors, the government has encouraged large business groups to gradually remove their circular shareholdings. In this paper, we propose a combinatorial optimization model that can answer the question, which equity investments among complicated investment relationships of one large business group should be removed to resolve its circular shareholdings. To the best knowledge of the authors, our research is the first one that has approached the circular shareholding problem in respect of management science. The proposed combinatorial optimization model are formulated into integer programming problem and applied to some Korean major business groups.

• 조명전기설비학회논문지
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• 제24권8호
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• pp.1-7
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• 2010

전력계통의 신뢰도와 배전계통의 유지보수는 매우 밀접한 관계가 있다. 본 논문에서는 정전비용의 최소화를 목적함수로 배전계통의 유지보수 계획을 수립하는 방안을 제시한다. 시변고장률을 이용하여 배전계통 내 특정설비의 고장으로 인한 정전비용을 수식화하고 공급구역의 정전비용을 목적함수로 최적화를 수행하며 경제성 분석을 통하여 투자비용 제약을 적용하여 유지보수를 위한 투자설비 우선순위를 결정한다. 제안한 방안을 검증할 모델계통은 국내의 도심지역 변전소를 통해 만들었으며, 제안된 방안의 신뢰도의 이득을 평가함으로서 그 타당성을 검증하였다.

• 품질경영학회지
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• 제51권4호
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• pp.573-588
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• 2023

Purpose: This study presents a research approach that utilizes deep reinforcement learning to construct optimal portfolios based on the business cycle for stocks and other assets. The objective is to develop effective investment strategies that adapt to the varying returns of assets in accordance with the business cycle. Methods: In this study, a diverse set of time series data, including stocks, is collected and utilized to train a deep reinforcement learning model. The proposed approach optimizes asset allocation based on the business cycle, particularly by gathering data for different states such as prosperity, recession, depression, and recovery and constructing portfolios optimized for each phase. Results: Experimental results confirm the effectiveness of the proposed deep reinforcement learning-based approach in constructing optimal portfolios tailored to the business cycle. The utility of optimizing portfolio investment strategies for each phase of the business cycle is demonstrated. Conclusion: This paper contributes to the construction of optimal portfolios based on the business cycle using a deep reinforcement learning approach, providing investors with effective investment strategies that simultaneously seek stability and profitability. As a result, investors can adopt stable and profitable investment strategies that adapt to business cycle volatility.

• 경영정보학연구
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• 제25권4호
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• pp.27-45
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• 2023

정보통신기술의 발달로 정보보호의 중요성이 커졌지만, 기업은 제한된 예산 내에서 적절한 대책을 선택하는 데 어려움을 겪고 있다. Sönmez and Kılıç(2021)는 정보 보안 침해를 완화하기 위한 최적의 투자 조합을 결정하기 위해 AHP 및 혼합 정수 계획을 사용하는 모델을 제안했다. 그러나 1) 보안 위협에 대한 보안 대책의 효과를 객관적으로 측정하지 못하고, 2) 투자로 인한 위험 감소가 투자 이전에 측정한 위험 수준을 초과하는 비현실적인 현상이 발생하고, 3) 여러 위협에 대해 단일 대응책을 사용할 때 중복된 투자가 이루어진다는 한계가 있었다. 본 연구에서는 베타 확률 분포를 사용하여 대책의 효과를 객관적으로 정량화하고, 위험 감소 수준이 투자 이전에 측정된 위험 수준을 초과하지 않고 보안 대책이 중복 투자되지 않도록 최적화 모델을 개선했다. 개선된 모델을 국내 중소기업을 대상으로 실증분석한 결과, Sönmez and Kılıç(2021)의 최적화 모델보다 더 나은 결과를 도출했다. 개선된 최적화 모델을 사용하면 정보보호 비용, 수량, 대책 효율성을 고려하여 고정된 예산 내에서 최적의 대책별 투자 포트폴리오를 도출할 수 있고, 정보 보안 예산을 확보하고 정보 보안 위협을 효과적으로 해결하는데 도움이 될 것이다.

• 충청수학회지
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• 제26권3호
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• pp.571-576
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• 2013

In this paper, we solve the optimal investment problem when the investor gets labor income and may have a wage increase. We assume the investor has constant absolute risk aversion(CARA) utility and obtain closed form solutions.