• 경영과정보연구
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• 제28권1호
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• pp.25-44
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• 2009

신규공모주(initial public offerings)는 기업의 중요한 자금조달 수단 중 하나에 속한다. 우리나라는 그 동안 신규공모주의 공모가를 산정하는 절차 및 제도에 많은 변화를 겪어 왔다. 특히 수요예측제도(book building)는 신규공모주의 공모가를 결정하는 방식에 있어서 획기적인 변화를 초래하였다고 볼 수 있다. 이에 본 연구는 코스닥시장을 대상으로 수요예측제도 도입 이후의 신규공모주의 장기성과를 분석한다. 본 연구에서는 분석결과에 신뢰성을 제고하고자 이벤트타임 포트폴리오(event time portfolio) 접근법과 더불어 캘린더타임 포트폴리오(calendar time portfolio) 접근법을 이용하여 신규공모주의 장기성과를 측정하였다. 본 연구의 결과는 다음과 같다. 이벤트타임 포트폴리오 접근법인 보유초과수익률(BHAR)과 누적초과수익률(CAR)을 이용한 분석에서 신규공모주의 장기성과가 통계적으로 유의한 양(+)의 값을 보이며, 왜도(Skewness)를 조정한 통계검정에서도 동일하게 나타났다. 또한, 상대적 부(Wealth Relatives)의 경우 대부분의 기간에서 1보다 크게 나타나 양(+)의 장기성과를 보였다. 캘린더타임 포트폴리오 접근법인 Fama-French의 3요인 모형, 캘린더타임 초과수익률(CTAR), RATS(Return Across Time and Securities) 모형 등을 이용한 분석결과, 신규공모주의 초과수익률이 대체로 유의한 양(+)의 값을 지니는 것으로 나타났다. 이러한 결과는 벤처기업 여부와 관계없이 모든 집단에 동일하게 나타남이 확인되었다. 따라서 본 연구결과는 신규공모주의 장기성과가 저평가되었다는 기존의 대다수 주장과 달리, 신규공모주가 장기적으로 고성과를 지닌다는 주장을 지지한다.

• 아태비즈니스연구
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• 제13권2호
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• pp.123-138
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• 2022

Purpose - This study compares the performances of dynamic asset allocation strategies using Korean stocks and U.S. dollar, which have been negatively correlated for a long time, to examine the diversification effects in the portfolios of them. Design/methodology/approach - In the current study, we use KOSPI200 index, as a proxy of the aggregated portfolio of Korean stocks, and USDKRW foreign exchange rate to implement various portfolio management strategies. We consider the equally-weighted, risk-parity, minimum variance, most diversified, and growth optimal portfolios for comparison. Findings - We first find the enhancement of risk adjusted returns due to risk reduction rather than return increasement for all the portfolios of consideration. Second, the enhancement is more pronounced for the trading strategies using correlations as well as volatilities compared to those using volatilities only. Third, the diversification effect has become stronger after the global financial crisis in 2008. Lastly, we find that the performance of the growth optimal portfolio can be improved by utilizing the well-known momentum phenomenon in stock markets to select the length of the sample period to estimate the expected return. Research implications or Originality - This study shows the potential benefits of adding the U.S. dollar to the portfolios of Korean stocks. The current study is the first to investigate the portfolio of Korean stocks and U.S. dollar from investment perspective.

• 대한수학회보
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• 제60권4호
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• pp.1101-1129
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• 2023

In this study we propose a model of optimal retirement, consumption and portfolio choice of an individual agent, which encompasses a large class of the models in the literature, and provide a methodology to solve the model. Different from the traditional approach, we consider the problems before and after retirement simultaneously and identify the difference in the dual value functions as the utility value of lifetime labor. The utility value has an option nature, namely, it is the maximized value of choosing the retirement time optimally and we discover it by solving a variational inequality. Then, we discover the dual value functions by using the utility value. We discover the value function and optimal policies by establishing a duality between the value function and the dual value function. The model and approach offer a significant advantage for computation of optimal policies for a large class of problems.

• 한국경영과학회지
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• 제39권2호
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• pp.83-95
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• 2014

In this paper, we develop a portfolio selection model that can be used to invest in markets with margin requirements such as the foreign exchange market. An investment algorithm to implement the proposed portfolio selection model based on objective historical data is also presented. We further conduct empirical analysis on the performance of a hypothetical investment in the foreign exchange market, using the proposed portfolio selection model and investment algorithm. Using 7 currency pairs that recorded the highest trading volume in the foreign exchange market during the most recent 10 years, we compare the performance of 1) the Dollar Index, 2) a 1/N Portfolio which equally allocates capital to all N assets considered for investment, and 3) a hypothetical investment portfolio selected and managed according to the portfolio selection model and investment algorithm proposed in this paper. Performance is compared in terms of accumulated returns and Sharpe ratios for the 10-year period from January 2003 to December 2012. The results show that the hypothetical investment portfolio outperforms both benchmarks, with superior performance especially during the period following financial crisis. Overall, this paper suggests that a mathematical approach for selecting and managing an optimal investment portfolio based on objective data can achieve outstanding performance in the foreign exchange market.

• 품질경영학회지
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• 제45권3호
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• pp.427-445
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• 2017

Purpose: This paper provides a method to identify cost-effective standards by analyzing the relationships between certified company and standards. It also aims to provide a evaluation model to establish a certification portfolio strategy of institutions. Methods: By analysing the networks of certified company and certification standards, this paper developed an evaluation model of standards. The evaluation model uses an index(Certificated Standard Evaluation Index; CSEI) to assess the value of standards. Results: To verify the applicability of the evaluation model, the proposed model and the CSEL index have been applied to certification standards of Korean Standard Association. The results show that the evaluation model can effectively identify potential customers and thereby establish a certification portfolio strategy. Conclusion: The main contribution of this study is a provision of a new approach to certification portfolio strategy by evaluating the value of standards. The proposed model is expected to provide implications for the certification portfolio strategy.

• Asian Journal of Business Environment
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• 제7권4호
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• pp.17-25
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• 2017

Purpose - The purpose of this study is to present a framework for determining the most appropriate business model for e-learning. Research design, data, and methodology - The Electronics Branch of Azad University has been elected as a case study in this research. This study conducted using a descriptive method. The information was obtained using interviews with experts including managers, faculty and students at the Electronics Branch of Azad University. Results - Three service-product system (product oriented system, use an oriented and result oriented system) approaches determined a framework for the formation of a portfolio. This portfolio is including three types of e-learning business models. Examining the relevant characteristics, correspondence of behaviorism learning theory with a product-oriented approach, correspondence of cognitivism theory with a user-oriented approach and in finally match correspondence of constructivist learning theory with a results-oriented approach which is evident. Conclusions - After reviewing the literature on the fields of e-learning, business model and product - service systems, we have achieved three types of e-learning business models. Then the variables in any of the business models were defined by using business model canvas tool and thus a portfolio consisting of three types of e-learning business model canvas was obtained.

• 경영과학
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• 제30권3호
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• pp.55-70
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• 2013

In this study we suggested two optimization models to determine conversion weight of convertible bonds. The problem of this study is same as that of Park and Shim [1]. But this study used Value-at-Risk (VaR) for risk measurement instead of CVaR, Conditional-Value-at-Risk. In comparison with conventional Markowitz portfolio models, which use the variance of return, our models used VaR. In 1996, Basel Committee on Banking Supervision recommended VaR for portfolio risk measurement. But there are difficulties in solving optimization models including VaR. Benati and Rizzi [5] proved NP-hardness of general portfolio optimization problems including VaR. We adopted their approach. But we developed efficient algorithms with time complexity O(nlogn) or less for our models. We applied examples of our models to the convertible bond issued by a semiconductor company Hynix.

• 경영과학
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• 제30권3호
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• pp.1-16
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• 2013

In this paper, we deal with an enhanced index fund strategy by implementing the exchange trade funds (ETFs) within the context of the Black-Litterman approach. The KOSPI200 index ETF is used to build risk-controlled portfolio that tracks the benchmark index, while the proposed Black-Litterman model mitigates estimation errors in incorporating both active investment views and equilibrium views. First, we construct a Black-Litterman model portfolio with the active market perspective based on the momentum strategy. Then, we update the portfolio with the KOSPI200 index ETF by using the equilibrium return ratio and weighted averages, while devising optimization modeling for improving the information ratio (IR) of the portfolio. Finally, we demonstrate the empirical viability of the proposed enhanced index strategies with KOSPI 200 data.

• 대한안전경영과학회지
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• 제15권4호
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• pp.407-416
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• 2013

This paper proposes an approach to analyzing the relationship between technology and services, and to identifying promising service areas for technology-based firms with the analysis of business model (BM) patents. First, BM patents and technology patents are collected and classified into their relevant categories, respectively. Second, patent citation analysis is conducted to analyze the linkage and impacts between each technology and service field at macro level. Third, as a micro level analysis, patent co-classification analysis is employed to identify the interrelationships among specific technology and service areas. Finally, the promising service areas for technology-based firms seeking service areas for diversification is investigated with portfolio analysis. The working of the proposed approach is provided with the help of a case study of IT and mobile services. The proposed approach could guide and help managers of technology-based firms to discover the opportunity of the diversification to new areas in emerging service fields.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.972-975
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• 2003

The purpose of this study is to integrate Decision Theory Approach(DTA) and OR Theory Approach(OTA) systemically. and to develop Combination Theory Approach to build an optimal R&D project portfolio by strategies. To Integrate two approaches. Utility theory is introduced. Evaluation Results aye converted into utility values by the utility functions and the values are optimized by 0-1 programming. Scoring method and Integer programming is used to evaluation a correspondence with a goal and to allocation the limiting resources. And utility function is used to reflect the preference of decision makers on the project evaluation.