• The Journal of Information Technology
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• v.9 no.3
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• pp.77-89
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• 2006

The event study analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Stock split announcements are generally associated with positive abnormal returns. It is important to investigate the responses of stocks to new information contained in the announcements of stock splits. So It is important to study the long term performance in the case of Stock Split. This Study forced to two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.153-163
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• 2009

Unlike the mean-variance approach, the stochastic dominance approach is to form a portfolio that stochastically dominates a predetermined benchmark portfolio such as KOSPI. This study is to search a set of portfolio weights for the first-order stochastic dominance with maximum expected return by managing the constraint set and the objective function separately. A nonlinear programming algorithm was developed and tested with promising results against Korean stock market data sets.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.1
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• pp.145-149
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• 2014

I consider the optimal consumption and portfolio selection problem with nonnegative wealth constraints using the dynamic programming approach. I use the constant relative risk aversion (CRRA) utility function and disutility to derive the closed-form solutions.

• The Journal of Asian Finance, Economics and Business
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• v.1 no.2
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• pp.31-37
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• 2014

The portfolio selection is one of the most important and vital decisions that a real or legal person, who invests in stock market, should make. The main purpose of this article is the determination of the optimal portfolio with regard to relations among stock returns of companies which are active in Tehran's stock market. For achieving this goal, weekly statistics of company's stocks since Farvardin 1389 until Esfand 1390, has been used. For analyzing statistics and information and examination of stocks of companies which has change in returns, factors analysis approach and clustering analysis has been used (FC approach). With using multivariate analysis and with the aim of reducing the unsystematic risk, a financial portfoliois formed. At last but not least, results of choosing the optimal portfolio rather than randomly choosing a portfolio are given.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.1-21
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• 2016

The Markowitz portfolio selection model uses estimators to deduce input parameters. However, the estimation errors of input parameters negatively influence the performance of portfolios. Therefore, this model cannot be reliably applied to real-world investments. To overcome this problem, we suggest an algorithm that can exclude stocks with large estimation error from the portfolio by applying a tracking signal to the Markowitz portfolio selection model. By calculating the tracking signal of each stock, we can monitor whether unexpected departures occur on the outcomes of the forecasts on rate of returns. Thereafter, unreliable stocks are removed. By using this approach, portfolios can comprise relatively reliable stocks that have comparatively small estimation errors. To evaluate the performance of the proposed approach, a 10-year investment experiment was conducted using historical stock returns data from 6 different stock markets around the world. Performance was assessed and compared by the Markowitz portfolio selection model with additional constraints and other benchmarks such as minimum variance portfolio and the index of each stock market. Results showed that a portfolio using the proposed approach exhibited a better Sharpe ratio and rate of return than other benchmarks.

• Journal of Engineering Education Research
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• v.15 no.4
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• pp.35-40
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• 2012

This study presents an analysis of the current situation (management, approach, adjustment, transportation, and others) of teaching portfolio by examining the teaching portfolio managers (staffs, researchers, teaching assistants, etc.) of 6 universities in the southeast of Korea. The rationale for the study focus is that the existing teaching portfolio either suffers a problem in the transportation, approach, adjustment and/or management or is likely to raise a problem in the future. In order to solve this problem, this study builds a web-based e-teaching portfolio. According to the analysis results, the engineering education system was established in all 6 universities (Ed- note that '6 universities' has already been specified as the study sample). The teaching portfolio was partially digitalized in this system, despite some problems of converting analog data into digital data, which induced difficulties in constructing the overall e-teaching portfolio. Therefore, this study focused on constructing an e-teaching portfolio without developing any additional system by using the existing system positively, and also on determining the appropriate components among the existing teaching portfolio components. Accordingly, in order to convert the analog data into the digital data required for this study, we used a digital camera as the conversion device and converted the teaching portfolio components into those appropriate for the e-teaching portfolio. Finally, we constructed an existing system appropriate for the e-teaching portfolio by using these devices and components.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.2
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• pp.329-336
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• 2016

The optimal portfolio choice problem with a stochastic income is considered in continuous-time framework. We provide a novel approach to treat the stochastic income when the market is complete. The developed method is useful to obtain closed-form solutions of the problems under borrowing constraints.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.134-137
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• 2007

Unlike the mean-variance approach, the stochastic dominance approach is to form a portfolio that stochastically dominates a predetermined benchmark portfolio such as KOSPI. This study is to search a set of portfolio weights for the first degree stochastic dominance with maximum expected return by managing the constraint set and the objective function separately. An algorithm was developed and tested with promising results against Korean stock market data sets.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.1
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• pp.25-36
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• 2003

Unlike the mean-variance approach, the stochastic dominance approach Is to form a portfolio that first-degree stochastically dominates a predetermined benchmark portfolio, e.g. KOSPI. Analytically defining the first derivative of the objective function, an optimal algorithm of nonlinear programming was developed to search a set of optimal weights systematically and tested with promising results against veal data sets from Korean stock market.

• The Journal of Fisheries Business Administration
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• v.45 no.1
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• pp.109-119
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• 2014

This study aimed to examine the applicability of a portfolio approach to the ecosystem-based fisheries management targeting the large purse seine fishery. Most fisheries are targeting multispecies and species are biologically and technically interacted each other. It enables a portfolio approach to be applied to find optimal production of each species through expected returns and risk analyses. Under specific assumptions on the harvest quota by species, efficient risk-return frontiers were generated and they showed a combination of optimal production level. Comparisons between portfolio and actual production provided a useful information for targeting strategy and management. Results also showed the possibility of effective multispecies fisheries management by imposing constraints on each species such as total allowable catch quotas.