New luminescent material, 6,11-Dihydroxy-5,12-naphthacenedione (Alq 2 -Ncd) was synthesized. And extended efforts have been made to obtain high-performance electro-luminescent (EL) devices, since the first report of organic lightemitting diodes (OLEDs) based on tris-(8-hydroxy-quinoline) aluminum (Alq 3 ). Current-voltage characteristics, brightness-voltage characteristics, luminous efficiency and external quantum efficiency were measured at room temperature. The maximum wavelength of the EL is at around 504 nm and the brightness is up to 2702 cd/m 2 with the maximum efficiency up to 3.91 lm/W.
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.
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