In the option pricing with martingale way, the most important aspect is finding the equivalent martingale measure to make the discounted stock price process become martingale.
在期权定价的鞅方法中最重要是找到等价鞅测度，使得贴现的股票价格过程是鞅。
2
In the spectrum bandwidth and cost aspect, Spectrometers with prisms and grating are equivalent.