心头很压抑.
努力,却为何又要退缩.
山盟海誓,承诺种种
现如今,却又是阴雨 绵绵.
只想停靠，哪怕不再远航

原来blog是避风港口。1团塞结在心中的无助，化解不了。
老板不在的日子，云淡风清，内心却暗潮涌动。

The fluctuation for the stock market these days serves as satisfied materials for stochastics learning. 

Originally, price of stock is concerned to fulfill the function: ds=udt+b*dW, where dW is a Wenier process.
However, in the process of huge simulation, S probably goes into negative, which contraticts the common 
sense. Thus, a new formular is put forward.

dLn(S)=a*S*dt+bS*dW. this guarantees that S remains in the positive interval. But in the long run, S is gradually
increasing. Still, it's not satisfactory to depict the fluctuation phenomenon.

Then comes up with the dLn(s)=(v-a*S)dt+b*dW. The formular would adjust the trend in the following ways.
if S goes too high, say, above v/a, the coefficient of dt turns to negative, subsquently pulls down the trend; 
vice vesa when the price is lower. This seems better. However, it implies that the voliatility constant.

Thus, the last version, seemingly more realisitic, dLn(S)=(v-a*s)dt+b*S^(1/2)dW. It not only includes the third version's 
merits, but also, gives the volatility a vivd exlaination, the higher the price, the higher the volatility, or the fluctuation.

Tango曲，5分25秒。
一步之遥，不可解读的悲伤。
第一次听到应该是在LG手机广告，那个惊艳的女子转身的刹那，曲调高潮部分的倾泻。
偶然的机会得以寻觅到这首曲子，终于有了机会完整欣赏一番。
曲子的中文译名取得很妙，一步咫尺，却遥在天涯。恰当地体现了曲子本身所赋予我的冲击。
华丽是第一印象，在转承起合间，华丽终于破碎，代之以浓重的悲情。
高潮的三次重现，每一次都迸发别具一格的力量。
咀嚼悲的意味，追逐华丽却在退去铅华后为别无它物而神伤。
真正渴望触及的，一步之远，却终于曲终散去，遥不可及了。