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Pricing Liquidity Risk with Heterogeneous Investment Horizons
We develop an asset pricing model with stochastic transaction costs and investors with heterogeneous horizons. Depending on their horizon, investors hold different sets of assets in equilibrium. This generates segmentation and spillover effects for expected returns, where the liquidity (risk) premium of illiquid assets is determined by investor horizons and the correlation between liquid and illiquid asset returns. We estimate our model for the cross-section of U.S. stock returns and find that it generates a good fit, mainly due to a combination of a substantial expected liquidity premium and segmentation effects, while the liquidity risk premium is small
Ultrafast all-optical wavelength conversion in silicon-insulator waveguides by means of cross phase modulation using 300 femtosecond pulses
In this paper we report the ultrafast all-optical wavelength conversion in Silicon-on-Insulator (SOI) waveguides. We used a pump-probe setup with 300 femtosecond pulses to demonstrate large temporal phase-shifts, caused by the Kerr effect and free carrier generation. Large wavelength shifts of a 1683nm probe signal have been observed. The wavelength conversion, ranging from 10nm redshifts to 15nm blueshifts, depending on the time delay between the pump and probe pulses, is caused by the pump induced Cross Phase Modulation. Furthermore, an all-optical switching scheme using SOI microring resonators is discussed. These results enable ultrafast all-optical switching using SOI microring resonators
Nd-complex-doped polymer channel waveguide laser
Laser operation at 1060 nm with slope efficiency of 0.95% and 440 μW output power for 2% outcoupling was demonstrated in Nd-complex-doped FDA/epoxy channel waveguides, in what to our knowledge is the first report of a rare-earth-ion-doped polymer waveguide laser. The threshold was 45 mW of absorbed pump power
Continuous-wave Lasers in Polymer waveguides
Channel waveguides based on a polymer, 6-fluorinated-dianhydride/epoxy, which is actively doped with a rare-earth-ion-doped complex, Nd(thenoyltrifluoroacetone)3 1,10-phenanthroline, have been fabricated. Photoluminescence peaks at 880 nm, 1060 nm, and 1330 nm have been experimentally observed. By optimization of the fabrication\ud
procedure of both, host material and optical structure, continuous-wave laser operation on both, the four-level and quasi-three-level transitions near 1060 nm and 880 nm, respectively, has been demonstrated in channel waveguides
Health inequalities and development plans in Iran: An analysis of the past three decades (1984–2010)
Introduction: Reducing inequalities in health care is one of the main challenges in all countries. In Iran as in other oil-exporting upper middle income countries, we expected to witness fewer inequalities especially in the health sector with the increase in governmental revenues.
Methods: This study presents an inequalities assessment of health care expenditures in Iran. We used data from the Household Income and Expenditure Survey (HIES) in Iran from 1984–2010. The analysis included 308,735 urban and 342,532 rural households.
Results: The results suggest heightened inequality in health care expenditures in Iran over the past three decades, including an increase in the gap between urban and rural areas. Furthermore, inflation has affected the poor more than the rich. The Kakwani progressivity index in all years is positive, averaging 0.436 in rural and 0.470 in urban areas during the time period of analysis. Compared to inequality in income distribution over the last 30 years, health expenditures continuously show more inequality and progressivity over the same period of time.
Conclusions: According to the result of our study, during this period Iran introduced four National Development Plans (NDPs); however, the NDPs failed to provide sustainable strategies for reducing inequalities in health care expenditures. Policies that protect vulnerable groups should be prioritized
Ultrafast all-optical wavelength conversion in silicon waveguides using femtosecond pump-probe pulses
Experimental results on ultrafast all-optical wavelength conversion in silicon-on-insulator waveguides are presented. Red and blue shifts of 10nm have been observed in femtosecond pump-probe experiments. Alloptical switching and the importance of waveguide dispersion are discussed
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