Cosmological inflation is widely considered an integral and empirically successful component of contemporary cosmology. It was originally motivated (and usually still is) by its solution of certain so-called fine-tuning problems of the hot big bang model, particularly what are known as the horizon problem and the flatness problem. Although the physics behind these problems is clear enough, the ...

transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

Micro data shows a significant dispersion in wealth at retirement at all levels of lifetime earnings and a weak correlation between lifetime earnings and retirement wealth. Previous research has shown that standard models have trouble generating these important features of the data. This paper studies a quantitative general equilibrium lifecycle model with intergenerational links of voluntary a...

Due to geographic and climatic conditions in mountainous northwest area, Roads in these areas are often covered with snow, ice and mud. Hence Transportation of equipment and soldiers encounter hardship and difficulties in rural area and specially outposts. To solve these problems, it is needed to fabricate portable roadway or traction mats. These high strength mats cover surface of roads and ar...