• 한국경영과학회지
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• 제38권4호
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• pp.35-52
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• 2013

Markowitz's portfolio selection model is used to construct an optimal portfolio which has minimum variance, while satisfying a minimum required expected return. The model uses estimators based on analysis of historical data to estimate the returns, standard deviations, and correlation coefficients of individual stocks being considered for investment. However, due to the inaccuracies involved in estimations, the true optimality of a portfolio constructed using the model is questionable. To investigate the effect of estimation inaccuracy on actual portfolio performance, we study the changes in a portfolio's realized return and standard deviation as the accuracy of the estimations for each stock's return, standard deviation, and correlation coefficient is increased. Furthermore, we empirically analyze the portfolio's performance by comparing it with the performance of active mutual funds that are being traded in the Korean stock market and the KOSPI benchmark index, in terms of portfolio returns, standard deviations of returns, and Sharpe ratios. Our results suggest that, among the three input parameters, the accuracy of the estimated returns of individual stocks has the largest effect on performance, while the accuracy of the estimates of the standard deviation of each stock's returns and the correlation coefficient between different stocks have smaller effects. In addition, it is shown that even a small increase in the accuracy of the estimated return of individual stocks improves the portfolio's performance substantially, suggesting that Markowitz's model can be more effectively applied in real-life investments with just an incremental effort to increase estimation accuracy.

• 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.

• 한국경영과학회지
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• 제39권2호
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• pp.49-66
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• 2014

This paper studies optimal consumption and investment behaviors of an individual when risky asset returns and her income are affected by the business cycle. The investor considers the incomplete information risk of unobservable macroeconomic conditions and updates her belief of expected risky asset returns through Bayesian learning. We find that the optimal investment strategy, certainty equivalent wealth, and portfolio hedging demand significantly depend on the belief about the macroeconomic conditions.

• International Journal of Advanced Culture Technology
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• 제10권3호
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• pp.220-225
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• 2022

The purpose of this study is to develop an e-teaching portfolio to perform a teaching portfolio of an instructor on the web. I order to carry out this study, an initial model of the e-teaching portfolio was developed through systematic literature review, and the final e-teaching portfolio was developed by selecting and applying five students, then modifying and supplementing them. The study period was from May 1 to May 20, 2022. As a result of the study, the components of the finally developed e-teaching portfolio are Step 1: Understanding oneself, Step 2: Goal setting, Step 3: Learning strategy, Step 4: Self-check. In conclusion, the program developed through this study is a convenient function that can process everything in one place by connecting the fragmented teaching results, and the developed e-teaching portfolio can promote interaction between individuals by building a community. It has possible characteristics. In order to systematically activate the e-teaching portfolio developed through this study, it is necessary to establish an online management system for systematic operation. Furthermore, an institutional device is needed to guarantee the result of the developed e-teaching portfolio. In order to continuously manage the quality of the teaching portfolio, extrinsic rewards that stimulate the instructor's intrinsic motivation should be provided.

• 공학교육연구
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• 제8권4호
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• pp.20-30
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• 2005

본 연구의 목적은 공학 프로그램의 교육목표에 따라 학생의 학습 성과 성취도를 높일 수 있도록 학생포트폴리오 관리프로그램을 개발하는 데 있다. 학생 포트폴리오 관리 프로그램(SPMP: Student Portfolio Management Program)은 인증요건, 학생들의 학습자료, 학습과제와 그 결과물들을 테이터 베이스 체계를 통하여 관리할 수 있도록 개발하였다. 또한 학생 포트폴리오 관리 프로그램은 공학교육인증에 있어서 요청되는 요건들을 통계적으로 처리하여 종합적으로 제공할 수 있도록 개발하였다. 학생포트폴리오 관리 프로그램을 구성하는 3가지 주요 기능은 첫째, 학생 개인 이력관리 기능으로서 개인정보자료, 교육프로그램에 관련된 자료 등 다양한 입력 자료로 구성되며 둘째, 학생 인증요건 관리 기능으로서 학습 성과, 이수과목 성적 등 인증요건 평가항목으로 구축되며 셋째, 학습과제관리 기능으로서 학습과제 작성, 검색 그리고 과제제출 항목들로 구성된다. 학생 포트폴리오 관리 프로그램을 통한 체계적인 프로젝트 관리는 공학인증이 목표로 하는 사회가 요구하는 능력 향상 및 인재양성에 긍정적인 효과를 가져 올 수 있다. 또한 관리 프로그램에서 제공하는 지속적인 결과물의 기록 및 관리는 대상 학생들이 자신의 포트폴리오를 상시로 필요한 곳에 제출 할 수 있게 도움을 준다.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1551-1556
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• 2012

본 연구에서는 KOSPI에 상장된 기업을 대상으로 기업의 효율성을 고려하여 포트폴리오를 구성하는 방안을 제시한다. 이를 위해 한국거래소(KRX)에서 구분하는 산업 업종별로 DEA(Data Envelopment Analysis) 기법을 이용하여 기업 효율성 분석을 실시하고 효율성이 우수한 기업들을 대상으로 마코위츠 모형을 통해 포트폴리오를 구성한다. 본 연구에서 제안한 포트폴리오 구성 방안의 성능 실험을 위해 KOSPI에 상장된 약 600개의 기업의 주식을 대상으로 4년 (2007~2010) 동안 매해 포트폴리오를 구성하였고 각각의 포트폴리오 수익률을 경영 효율성을 고려하지 않고 구성한 포트폴리오 및 시장 수익률과의 비교 분석을 통해 그 우수성을 입증하였다.

• 한국산학기술학회논문지
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• 제12권9호
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• pp.3849-3855
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• 2011

본 연구에서는 배당을 중심으로 한 기업의 성장가능성을 평가하여 효율적 포트폴리오를 선택하는 전략을 제시한다. 이를 위해 선행실험을 통해 양질의 성장주를 가려내기 위한 4 개의 범주(category)를 선정하고, 각 범주별 점수 산출식을 포함하는 스코어링 테이블을 개발하였다. 스코어링 테이블에 의해 구성된 포트폴리오의 효과를 보이기 위해 한국거래소에 상장된 KOSPI 및 KOSDAQ의 927개 주식을 대상으로 2007~2010년의 4년 동안 매해 3 그룹의 포트폴리오를 구성하였고, 각 포트폴리오의 수익률을 시장수익률과 비교 분석을 실시하여 그 성능을 입증하였다.

• 유통과학연구
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• 제17권9호
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• pp.117-125
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• 2019

Purpose - We investigate how to increase consumer incentives to buy public offering funds, resulting in activating the public offering fund market. In particular, this study aims to find ways to expand diversity and to improve efficiency of public offering fund. The public fund market of Korea has been stagnant in recent years. However, the public offering fund market plays a very significant role in terms of consumer welfare. Since only a few wealthy investors can participate in the private equity market, the stagnation in the public offering fund market usually reduces the opportunity of consumer's buying funds thus ultimately affecting their future wealth. Research design, data, and methodology - To attain our purpose, the 'factor-based portfolio strategy' has been considered. It is an alternative portfolio strategy, which composites the advantages of the passive management and active management. For our empirical anaylsis, we used global stock distribution market data over the period of 1991 and 2016. Then we constructed portfolios based on firm-size, firm-value, and momentum. Finally, a regression model was set, then hypotheses were tested, analyzing the performances. Results - First, among the 15 factor-based portfolios of global, Europe, Asia-Pacific(ex Japan), US and Japan, in eight portfolios, positive excess returns are observed at 5% significance level. Further, there is another portfolio with positive excess return at 10% significance level. Second, most of the portfolios with significant excess performance show positive relationship with the market portfolio. However, the firm-value based portfolio in Asia-Pacific region shows no relationship, and the firm-value based portfolio in US shows negative relationship. Third, we confirmed that the two firm-value factor portfolios in Asia-Pacific region and US, not having positive relationship with market portfolio, provide significant excess returns. Conclusions - In this paper, we provide empirical evidences supporting that the factor-based portfolios expand the diversity of funds and improve the efficiency of investment performance. However, there is no guarantee that the efficiency will continue in the future. In addition, various constraints and costs must be considered. Nevertheless, our novel findings in the advanced financial market such as US and Asia-Pacific are very interesting and offers important implications.

• 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.

• 대한산업공학회지
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• 제39권4호
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• pp.260-270
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• 2013

This paper proposes a strategic portfolio model for managing performance of online games. The portfolio matrix is composed of two dimensions: financial performance and non-financial performance. Financial performance is measured by the conventional measure, average revenue per user (ARPU). In terms of non-financial performance, five non-financial key performance indicators (KPIs) that have been widely used in the online game industry are utilized: RU (Register User), VU (Visiting User), TS (Time Spent), ACU (Average Current User), MCU (Maximum Current User). Data envelopment analysis (DEA) is then employed to produce a single performance measure aggregating the five KPIs. DEA is a linear programming model for measuring the relative efficiency of decision making unit (DMUs) with multiple inputs and outputs. This study employs DEA as a tool for multiple criteria decision making (MCDM), in particular, the pure output model without inputs. Combining the two types of performance produces the online game portfolio matrix with four quadrants: Dark Horse, Stop Loss, Jack Pot, Luxury Goods. A case study of 39 online games provided by company 'N' is provided. The proposed portfolio model is expected to be fruitfully used for strategic decision making of online game companies.