• Journal of Construction Engineering and Project Management
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• 제1권3호
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• pp.28-37
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• 2011

Domestic construction companies are suffering from financing difficulties in the wake of the economic slump in Korea and abroad. During this economic slump, real estate investment trusts (REITs), facilitators for improving financing and stimulating construction businesses, have increasingly expanded since their introduction in 2001. However, in terms of growth speed and marketing size, Korean REITs are falling behind those of other nations. The purpose of this study is to suggest a method for composing a portfolio using the Markowitz portfolio selection model to stimulate REITs. The main contents are as follows. First, a comparative analysis was conducted of increased REIT profit with the application of the Markowitz model and the average REIT profit rate from July 3, 2007, to July 21, 2008, during the investment analysis periods. The results showed that the total profit rate from the Markowitz model was about 10% higher than the average REIT profit rate. Second, the sensitivity was analyzed according to the portfolio's data-gathering and replacement cycle to measure the optimum cycle and yield. The six-mouth profit data collection period showed about 16% higher profits with the Markowitz model than with the REITs. The two-week portfolio change period resulted in about 11% higher profits with the Markowitz model than with the REITs.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5809-5818
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• 2013

본 논문에서는 '파이프라인 건전도(Pipeline Soundness)와 특허유효성(Patent Validity)개념을 적용하여 제약기업이 적합한 기술 아웃소싱 대상기업을 선정하기 위한 기술 포트폴리오 방법을 제시하고자 한다. 또한 이를 최근 발표한 Amgen의 Onyx Pharmaceuticals 인수사례에 적용하여 개발된 포트폴리오 분석방법의 실제 적용 가능성을 검토하고 사례기업의 기술아웃소싱 타당성을 분석하기로 한다. 본 연구를 통해 제시된 기술포트폴리오의 사례 적용 분석 결과 Amgen은 주력분야인 Cancer 분야의 특허유효성 개선이 시급한 것으로 분석되었으며 Onyx Pharmaceuticals의 인수를 통해 Cancer 분야의 기술포트폴리오를 안정적인 영역에 도달시킬 것으로 기대된다. Amgen의 실제 Onyx Pharmaceuticals 인수 이유 또한 Cancer 분야의 파이프라인 강화와 의약품 도입이라는 점을 고려할 때 새롭게 개발된 기술포트폴리오 분석방법이 실제사례에 잘 적용됨을 알 수 있었으며, 본 연구를 통해 개발된 기술포트폴리오 분석 방법이 제약기업의 기술현황 파악 및 인수대상기업 선정을 위한 도구로 충분히 활용 가능할 수 있을 것으로 판단된다.

• Journal of the Korean Data and Information Science Society
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• 제25권1호
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• pp.107-117
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• 2014

본 연구에서는 투자자 거래 정보를 활용한 포트폴리오 투자전략을 제안했다. 포트폴리오를 구성하는 과정에서 군집분석을 활용하여 기대수익이 높은 종목을 선정하고, 유전자 알고리즘으로 포트폴리오를 최적화하여 투자성과를 높이고자 했다. 2007년 4월부터 2013년 6월까지의 국내 주식시장을 대상으로 한 실증분석을 통하여, 본 연구에서 제안한 포트폴리오 투자전략의 유용성과 우수성을 확인 했다. 본 연구의 결과는 특정 투자 주체의 매매행태를 분석하여 투자 의사결정에 이용할 수 있으며, 이를 통하여 높은 투자성과를 얻을 수 있음을 보여준다. 또한 인공지능 기법이 투자 의사결정에 유용하게 사용될 수 있음을 시사한다.

• 한국정보시스템학회지:정보시스템연구
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• 제28권3호
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• pp.203-225
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• 2019

Purpose The purpose of this study is to empirically verify an ePortfolio success model which shows the structural causal relationships among the basic modeling constructs. We developed the success model based on DeLone and Mclean(2003) from IS perspective and on Balaban et al(2013) from ePortfolio perspective. And we are focused on the success of ePortfolio system designed for college students and professors. Design/methodology/approach Structural equation modeling techniques were applied to data collected 375 users of the ePortfolio system, K-Folio, at least one semester during one academic year. The structural model was analyzed using a Lisrel 8.54 statistical program. Findings The followings are the findings of the study. First, the constructs of IS success model are well applied to ePortfolio for college education. Second, the proposed model which has direct causal relationships from ePortfolio's quality to performance is more significant than the D&M and Balaban's model(2013). Third, the information quality among ePortfolio quality constructs does not have effect on system usability and performance. It means that information contents' quality issued by professor or system manager is not satisfied with the students yet. Finally, by using indirect analysis of structural equation model, we found that the ePortfolio operation manager should focus on ensuring system maintenance activities and providing fast and accurate services for improving ePortfolio performance.

• 산업경영시스템학회지
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• 제46권4호
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• pp.63-73
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• 2023

This study explores modern portfolio theory by integrating the Black-Litterman portfolio with time-series clustering, specificially emphasizing K-shape clustering methodology. K-shape clustering enables grouping time-series data effectively, enhancing the ability to plan and manage investments in stock markets when combined with the Black-Litterman portfolio. Based on the patterns of stock markets, the objective is to understand the relationship between past market data and planning future investment strategies through backtesting. Additionally, by examining diverse learning and investment periods, it is identified optimal strategies to boost portfolio returns while efficiently managing associated risks. For comparative analysis, traditional Markowitz portfolio is also assessed in conjunction with clustering techniques utilizing K-Means and K-Means with Dynamic Time Warping. It is suggested that the combination of K-shape and the Black-Litterman model significantly enhances portfolio optimization in the stock market, providing valuable insights for making stable portfolio investment decisions. The achieved sharpe ratio of 0.722 indicates a significantly higher performance when compared to other benchmarks, underlining the effectiveness of the K-shape and Black-Litterman integration in portfolio optimization.

• 지식경영연구
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• 제19권3호
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• pp.63-87
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• 2018

In a rapidly changing technology environment, managing and rearranging the patent portfolios is one of the main sources of competitive advantage for firms. This study analyzes the effects of patent portfolio composition on new product introduction related to resource allocation. This study also looks at the moderating role of rearranging the patent portfolios on new product introduction. Our empirical analysis of the global pharmaceutical industry shows that firms with high-value patent portfolios exhibit a tendency to launch new products, and patent portfolio diversity shows a U-shaped relationship with new product introduction. In addition, the patent portfolio rearrangement positively moderates the relationship between patent portfolio diversity and new product introduction. The results are expected to provide implications for firms' patent portfolio composition and patent portfolio rearrangement related to innovation performance such as new product introduction.

• 경영과학
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• 제26권2호
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• pp.19-35
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• 2009

This paper investigated performance of the Markowitz's portfolio selection model with applications to Korean stock market. We chose Samsung-Group-Funds and KOSPI index for performance comparison with the Markowitz's portfolio selection model. For the most recent one and a half year period between March 2007 and September 2008, KOSPI index almost remained the same with only 0.1% change, Samsung-Group-Funds showed 20.54% return, and Markowitz's model, which is composed of the same 17 Samsung group stocks, achieved 52% return. We performed sensitivity analysis on the duration of financial data and the frequency of portfolio change in order to maximize the return of portfolio. In conclusion, according to our empirical research results with Samsung-Group-Funds, investment by Markowitz's model, which periodically changes portfolio by using nonlinear programming with only financial data, outperformed investment by the fund managers who possess rich experiences on stock trading and actively change portfolio by the minute-by-minute market news and business information.

• 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.

• 한국안전학회지
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• 제27권4호
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• pp.121-127
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• 2012

Vehicle Inspection System is to examine the condition of vehicle regularly at the national level to protect lives and properties of the people from traffic accidents due to vehicle's fault. However, the vehicle inspection method, criteria, period and effectiveness have become a controversial issue, because of examining safety management of vehicle by drivers regardless of regular vehicle inspection. Therefore, the aim of this study is to investigate vehicle inspection timeliness and risk level of inspection items through basic statistical survey and portfolio analysis. The results of the research through practical analysis are: (1) The inspection failure rates between 3 and 6 model year tend to increase. (2) The failure of inspection items for safety highly impacts on traffic accident rate in terms of accident risks. (3) According to the result of portfolio analysis, faulty items located 1st quadrant are riding device, driveline system, controlling device, steering actuator, and fuel system.

• 품질경영학회지
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• 제31권3호
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• pp.160-171
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• 2003

Criteria for the comparison of quality of asset portfolio management are risk and return. In this paper a method to use structural time-series model to determine an optimal portfolio for the improvement of quality of asset portfolio management is suggested. In traditional mean variance analysis expected return is assumed to be time-invariant. However, it is more realistic to assume that expected return is temporally dynamic and structural time-series model can be used to reflect time-varying nature of return. A data set from an insurance company was used to show validity of suggested method.