• Knowledge Management Research
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• v.19 no.3
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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.

• Korean Management Science Review
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• v.26 no.2
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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.

• The Journal of the Korea Contents Association
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• v.8 no.5
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• pp.260-267
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• 2008

The portfolio provides a method which can properly evaluate the student's long term period of learning and growth, and this allows students to have practical learning through self-reflection. However, following the realities of portfolio's operation, the portfolio is being operated formally just once only for the evaluation due to the difficulty of long custody and its time-consuming process. In this paper, after grasping the overall process of learning and the result of growth, we design the 'e-portfolio' which combines both learning and evaluation in order to minimize the physical constraint factors along with operating portfolio. After operating our newly designed 'e-portfolio' based on blog in order to verify it's effect, we found the meaningful changes in student's academic achievement and the positive possibility of its application to teachers. Therefore, with the operation of our suggested 'e-portfolio', we are expecting progressed and integrated portfolio education which combines the function of the learning and the evaluation.

• Journal of Korean Elementary Science Education
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• v.24 no.3
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• pp.301-309
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• 2005

The purpose of this study was to investigate the measuring range of portfolio assessment on students' abilities, using correlation coefficients of portfolio assessment with four other assessment methods. A portfolio system was developed based on low units of elementary fourth grade science, and applied to three fourth-grade science classes in Daejeon Metropolitan area and Gyunggi-do. Four different assessment methods, multiple-choice (short answer type), essay-type item, mind-mapping and laboratory assessment were also administered and scored by two elementary teachers attending graduate school. Correlation coefficients between portfolio assessment and four assessment methods were calculated with SPSS. Portfolio assessment showed moderate correlation with multiplechoice (short answer), essay-type, and mind-mapping, and low correlation with laboratory assessment. Portfolio assessment showed high correlation with multiple-choice assessment in 'understanding' and 'application' domains, but showed low correlation in 'recall' and 'inquiry' domains. In conclusion, portfolio assessment could measure various abilities measured by other assessment methods.

• Journal of Engineering Education Research
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• v.13 no.1
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• pp.70-77
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• 2010

The purpose of this study was to verify the educational value of student portfolio and to give the direction of making student portfolio. Qualitative research method was used to accomplish objectives of the study. 9 students who were winner in competition of student portfolio in I University at Incheon Province were interviewed. Data were recorded, transcribed and analyzed. Most students started to make student portfolio by compulsory, but they realized that it was necessary to start student portfolio from the lower grades. They had difficulties in not having materials of activities and hesitated at the beginning of making student portfolio even though they got standard form from the university. Students recognized that making student portfolio was effective tool because it could enhance self-reflection, awareness of importance of record, preparation of future, obtaining of motivation for anonther activities, getting self-confidence, and improvement of writing skill.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.83-94
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• 2007

The portfolio can be used as a methodology supporting the learning of constructivism. Recently, the use of portfolios has been increased gradually in the education field, but a study on the current state analysis and design direction of portfolios leaves much to be desired. In this paper, we analyze statistical data on the portfolio application of teachers in domestic elementary, middle, and high school. We also propose a design direction of e-portfolio needed in the society of knowledge information based on this analysis. The results of research show that the following problems will be improved: understanding portfolio, analyzing the current state according to the types of portfolio application, designing a distinguished system according to the level of school, expanding education of teachers with high career, and developing a guide helper. The design of total system that combines the learning and evaluation is needed to improve a problem that spends lots of time to make portfolio, and operates temporally and formally achievement evaluation. In addition, the design of e-portfolio supporting efficiently interaction and self-directed teaming is required.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.107-116
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• 2008

This paper deals with modelling and introducing of the project portfolio construction and evaluation problem under uncertainty. The common way in industry of managing project portfolio is construction of initial portfolio considering uncertainties which exist inside and outside of portfolio, and periodic revision of portfolio due to the deviation from plans. In this paper, we introduce algorithm which reflecting the industrial common practice of initial planning and periodic revision. With this simulation method, probabilistic distribution of portfolio's performance in consideration can be found.

• Industrial Engineering and Management Systems
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• v.13 no.4
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• pp.442-448
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• 2014

Portfolio optimization in the presence of estimation error can be stabilized by incorporating norm-constraints; this result was shown by DeMiguel et al. (A generalized approach to portfolio optimization: improving performance by constraining portfolio norms, Management Science, 5, 798-812, 2009), who reported empirical performance better than numerous competing approaches. We extend the idea of norm-constraints by introducing a powerful enhancement, grouped selection for portfolio optimization. Here, instead of merely penalizing norms of the assets being selected, we penalize groups, where within a group assets are treated alike, but across groups, the penalization may differ. The idea of groupwise selection is grounded in statistics, but to our knowledge, it is novel in the context of portfolio optimization. Novelty aside, the real benefits of groupwise selection are substantiated by experiments; our results show that groupwise asset selection leads to strategies with lower variance, higher Sharpe ratios, and even higher expected returns than the ordinary norm-constrained formulations.

• The Mathematical Education
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• v.52 no.2
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• pp.175-190
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• 2013

The purpose of this article is to suggest using portfolio for professional development of secondary pre-service mathematics teachers based on actual application case. To achieve this goal, 28 pre-service mathematics teachers developed their own portfolios in the regular study course for one semester under the pre-planned components of portfolio. Then they participated in the survey of their beliefs in mathematics and mathematics education and in the structured interview for drawing implications of using a pre-service mathematics teacher portfolio. According to the collected data, developing a pre-service mathematics teacher portfolio made a significant difference in beliefs of mathematics teachers' roles and showed the potential to improve the professional development of pre-service mathematics teachers as well as their learning. Continued investigation for more effective components of a pre-service mathematics teacher portfolio would be needed.

• IE interfaces
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• v.25 no.2
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• pp.163-169
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• 2012

This paper proposes an efficient portfolio management methodology named sSPPM with consideration of risk and required return. sSPPM employs Markowitz's portfolio model to select securities and adopts ($s$, $S$) policy that is a well-known technique in the inventory control area to revise the current portfolio. Computational experiments using virtual stock prices generated by monte carlo simulation method as well as real stock ones of KOSPI for recent 4 years are conducted to show the excellence of the portfolio management under ($s$, $S$) policy framework. The result shows that sSPPM is remarkably superior to both 6 or 12 months based periodic portfolio revision method and market (KOSPI index).